IP6 GOLD – originalna formula.
IP6 Gold predstavlja novi standard najčistijih i najpotentnijih suplemenata IP6 (Inozitol heksafosfata) i Inozitola koji se mogu naći u svetu. IP6 Gold je dijetetski suplement.
Ovaj tekst je edukativnog karaktera, namenjen za opšte obrazovanje i u informativne svrhe, nije zamena za profesionalni medicinski savet, ispitivanje, dijagnozu ili lečenje. Svaka izjava je linkovana (zelena boja) ka publikovanom naučnom radu objavljenom na “Medline” (najvećoj u svetu medicinskoj elektronskoj naučnoj bazi podataka koju održava Američka vlada).
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Najvažnije pravilo u medicini je “Primum non nocere” to je latinski izraz koji znači “prvo , ne nanesi nikakvo zlo “. Jako malo preparata u svetu može da se pohvali time. IP6 i Inozitol može time da se pohvali.
IP6 i Inozitol nalaze se na listi GRAS (Generally Recognized as Safe – opšte priznatih bezbednih) supstanci sastavljenoj od strane američke Uprave za hranu i lekove (FDA); GRAS je oznaka FDA da stručnjaci smatraju hemikaliju ili supstancu koja se dodaje hrani bezbednom. IP 6 sa inozitolom se prirodno nalazi u svakoj ćeliji tela. Opsežne istraživačke studije ukazuju na to da IP 6 i Inozitol su potpuno bezbedna prirodna kombinacija.
Naučna istraživanja dokazuju da IP6 i Inozitol (Pogledajte svaki link ka objavljenom naučnom radu)
- poboljšava zdravlje srca (http://www.ncbi.nlm.nih.gov/pubmed/1929656)
- pomaže održavanje normalnog metabolizma glukoze (http://www.ncbi.nlm.nih.gov/pubmed/15999878?ordinalpos=2)
- stimuliše ćelije pankreasa da luče insulin, snižava nivoe glukoze u krvi, sprečava i poništava mnoge komplikacije dijabetesa (http://www.ncbi.nlm.nih.gov/pubmed/12837755?ordinalpos=1)
- snažno antikancerogeno dejstvo (http://www.ncbi.nlm.nih.gov/pubmed/17044765)
- podstiče proces preobražaja maligne ćelije indukujući diferencijaciju u njoj da se ponaša kao normalna (http://www.ncbi.nlm.nih.gov/pubmed/17044765)
- preventivno dejsvo na ćelije raka (http://www.ncbi.nlm.nih.gov/pubmed/16896044)
- stimuliše aktivnost NK ćelija (glavna uloga NK ćelija u organizmu je borba protiv tumorskih ćelija, virusa i njihova eliminacija) (http://www.ncbi.nlm.nih.gov/pubmed/16124063)
- prevencija Multiple skleroze (http://ip-6.net/other-benefits.html)
- sprečava kardiovaskularnu kalcifikaciju (http://www.ncbi.nlm.nih.gov/pubmed/18508720)
- smanjuje abnormalnu lepljivost (agregaciju) trombocita. (http://www.ncbi.nlm.nih.gov/pubmed/10625941)
- preventivno dejstvo na osteoporozu kod žena u postmenopauzi (http://www.ncbi.nlm.nih.gov/pubmed/22905230)
- pokazuje jak afinitet prema uranijumu, štiti od raznih oblika zracenja (http://www.ncbi.nlm.nih.gov/pubmed/21819680)
B vitamin inozitol i njegov derivat IP6 (inozitol heksafosfat) su sveprisutni, u zemljištu, semenu biljaka poput pirinča, kukuruza, soje, pšenice, susama, kao i u svim ćelijama sisara. IP6 + Inozitol ponašaju se kao koktel širokog spektra dejstva koji sprečava pojavu raka, poboljšava imunitet, pomaže u snižavanju holesterola, sprečava pojavu kamenja u bubregu i komplikacija koje izaziva dijabetes, i smanjuje rizik od kardiovaskularnih oboljenja, uključujući infarkt, moždani udar, itd.
IP6 (ili InsP6) je cikloheksanheksol, ugljeni hidrat (inozitol) sa 6 fosfatnih grupa prirodno zasićenih Ca++ i Mg++. Njegovo prisustvo u semenkama otkrio je 1855.-1856. Hartig; zbog svog biljnog porekla nazvan je “fitin”, a 1910. razjašnjena je njegova molekularna struktura, mio-inozitola-1,2,3,4,5,6-heksa dihidrogen fosfata. Poznat i kao fitinska kiselina, okrivljen je za nedostatak minerala (kalcijuma, gvožđa, cinka itd.) kod određenih vrsta ljudske populacije.
Eksperimenti o antikancerogenim svojstvima Inozitola & Cal Mag IP6 izvedeni su po prvi put u laboratoriji Prof AbulKalam M Shamsuddin MD PhD, da bi ih kasnije naučnici širom svete reprodukovali i proširili, i potvrdili ova fascinantna otkrića. Inozitol & Cal Mag IP6, i drugi fosfati inozitola, tj. IP1, IP2, IP3, IP4, IP5 obično su prisutni u svim ćelijama sisara. IP3 je ključni molekul odgovoran za prenos signala, kontroliše vitalne funkcije, uključujući ćelijsku proliferaciju i diferencijaciju. IP6 može otpustiti jedan ili više fosfata (P) dok ih inozitol može primiti. Zato kombinacija Inozitola & Cal Mag IP6 može doneti više ključnog IP3. Teorija je sledeća: pošto i) svi kanceri, bez obzira na vrstu i poreklo, imaju zajednički nedostatak nekontrolisane proliferacije ćelija, ii) IP3 je ključni regulator ćelijskog rasta i iii) pomoću Inozitol a & Cal Mag IP6 dobija se IP3, stoga bi, Inozitol & Cal Mag IP6 trebalo da budu efikasni protiv mnogih različitih vrsta kancera, i to kod svih vrsta.
Prof AbulKalam M Shamsuddin MD PhD i ostali su pokazali u proučavanjima ćelija raka i kod životinja i kod ljudi da IP6 smanjuje stopu ćelija raka, tako što smanjuje proizvodnju nove DNK. Pošto ne vrši istu inhibiciju u normalnim ćelijama, IP6 se dramatično razlikuje od uobičajenih antikancerogenih agenasa. Lekovi za hemoterapiju, na primer, deluju tako što bukvalno ubijaju sve ćelije bez razlike, i rezultat je da su prilično toksični, jer ubijaju i dobre i loše. IP6 se dramatično razlikuje jer pomaže ćeliji da funkcioniše normalno, bez oštećenja zdravih ćelija.
Tokom preobražaja normalnih ćelija u maligne, ćelije raka gube normalne šablone ponašanja, i taj fenomen se zove dediferencijacija. Istovremeno, one takođe izgledaju drugačije: ćelije raka imaju veće telo (citoplazmu) i disproporcionalno veliko jedro, tj. povećanu razmeru jedro: citoplazma. Još jedan široko rasprostranjen mehanizam dejstva IP6 & Inozitola je preokretanje tog procesa ili vraćanje diferencijacije ćelija u normalu, tako da maligne ćelije počinju i da izgledaju kao normalne ćelije.
Nekoliko kliničkih studija o delotvornosti IP6+Inozitola predstavljeno je na 7. Međunarodnoj konferenciji o istraživanjima u borbi protiv raka održanoj na Krfu u Grčkoj 25.-30. oktobra 2004. One su obuhvatile rak debelog creva, pluća i dojke. Pacijenti su prošli tretman IP6+Inozitolom (8-24 gm/dan) i sa i bez paralelne standardne hemoterapije i/ili zračenja. Primećeno je da su IP6+Inozitol smanjili nuspojave hemoterapije i zračenja, delovali u sinergiji i omogućili bolje efekte terapije; u najmanju ruku, pacijentima se povećao kvalitet života(Anticancer Research Volume 24 No. 5D, September – October 2004; pages 3474-3475 and 3617-3618). Levo je prikazan CT snimak šezdesettrogodišnjeg pacijenta s IV stadijumom raka debelog creva s metastazama na jetri i njegovo smanjenje u period od 4 meseca.
Za razliku od većine antikancerogenih agenasa, IP6 i Inozitol nisu citotoksični, tj. oni sami ne ubijaju ćelije raka u farmakološkoj dozi; u velikim dozama izazivaju apoptozu (programiranu ćelijsku smrt). IP6 i Inozitol pre svega teraju ćelije raka da se ponašaju i izgledaju kao normalne ćelije (diferencijacija). Dok ćelije raka rastu nekontrolisano, diferencirane ćelije ne rastu. Povećana diferencijacija uzrokovana IP6 primećena je u svim testiranim ćelijskim linijama raka, odnosno ćelijskim linijama raka dojke, debelog creva, prostate, leukemije, rabdomiosarkoma (raka mišićnog tkiva u detinjstvu), i ćelijskih linija jetre. Posledica tretmana IP6 je smanjenje sekrecije ili ekspresije različitih tumorskih markera ovih kancera; npr. PSA (antigena specifičnog za prostatu) kod raka prostate, alfa feto-proteina (AFP) kod raka jetre, itd. Stoga se efikasnost tretmana IP6+Inozitol može pratiti preko nivoa markera tumora.
Još jedan način na koji se IP6+Inozitol bore protiv kancera je poboljšanjem imuniteta. Iako sami IP6+Inozitol ne ubijaju direktno ćelije raka, postoji podtip T-limfocita koji se zove ćelije ubice (NK ćelije) i koji radi baš to. A njihovu sposobnost ubijanja ćelija raka IP6+Inozitol povećavaju (KARCINOGENEZA tom 10: s. 1461-1463 & 1595-1598, 1989; Patent SAD #5,082,833). Nedavno objavljeni rad profesora Zhang Z i grupe autora Zhang Z, Song Y, Wang XL) (potvrđuje sposobnost IP6 da poboljša aktivnost NK ćelija. U martu 2010. u radu objavljenom u ONKOLOŠKOM IZVEŠTAJU (tom 23: s. 787-793), dr. L. Šroterova i njene kolege s Karlovog univerziteta iz Praga, Republika Češka potvrdili su da je kombinacija IP6+Inozitola najbolja za inhibiciju rasta ćelija raka. Testirali su i IP6 i Inozitol (Ins) pojedinačno, i zajedno na različitim ćelijskim linijama raka kod ljudi (HT-29, SW-480 i SW-620) dobijenih od kolorektalnog carcinoma u različitim stadijumima. Dejstvo IP6, Inozitola ili IP6+Inozitola na ćelije mereno je korišćenjem testa metaboličke aktivnosti, testa sinteze proteina i apoptoze “s jasnim indikacijama da je Ins pojačao proapoptičko dejstvo IP6 na sve proučavane ćelijske linije [raka].”, kako su autori zaključili.Molimo vas, pogledajte skorašnje izveštaje o klničkim testiranjima inozitola kod pacijenata s rakom pluća objavljenih u večernjim vestima NBC od 7. aprila 2010. “Novi test identifikuje pušače sklone dobijanju raka pluća.” S obzirom na činjenicu (molimo vas, pogledajte gore) da kombinacija IP6+ Inozitola daje najbolje rezultate, studija predstavlja ohrabrujući prvi korak.
Prevencija pojave Alchajmerove, Parkinsonove, multiple skleroze, kamena u bubregu – pomoću vitamina?!
Patentni zavod SAD izdao je nekoliko patenta za korišćenje IP6 za lečenje Alchajmerove bolesti, multiple skleroze i Parkinsonove bolesti. Rad laboratorije dr Mandžu Redi u SAD-u pokazuje “značajno neurozaštitno dejstvo” IP6 na ćelijski model Parkinsonove bolesti. Profesor Grases iz Španije sugerisao je da manjak IP6 može predstavljati faktor rizika za Alchajmerovu bolest i tačno godinu dana kasnije u januaru 2011, rad objavljen u Časopisu Alchajmerove bolesti pokazao je efikasnost IP6 u lečenju na eksperimentalnim modelima; “…[IP6] može obezbediti održivu opciju lečenja AD [Alchajmerove bolesti]”, zaključuju autori. Profesor DžoEn Maklorin i njene kolege s Univerziteta u Torontu dokazali su da inozitol može da se veže s amiloid β proteinom (Aβ) – krivcem za uništavanje ćelija mozga, i tako smanji toksičnost Aβ. “…lečenje pacijenata obolelih od AD-a inozitolom može pomoći u sprečavanju taloženja Aβ i toksičnosti izazvane Aβ.”, zaključuju autori. Zato će se kombinacija inozitol + IP6 verovatno efikasnije boriti protiv ovog bauka nego bilo koji od ta dva elementa zasebno.
Profesor Grases i njegove kolege takođe su pokazali da IP6 sprečava kardiovaskularnu kalcifikaciju. Abnormalna ili patološka kalcifikacija mekog tkiva poput krvnih sudova, srca, itd. može imati ozbiljne posledice kad su u pitanju ateroskleroza i infarkt miokarda. Zato sprečavanje patološke kalcifikacije u telu smanjuje rizik od kardiovaskularnih bolesti. Još jedan kritični faktor kod kardiovaskularnih bolesti je tromboza krvnih sudova u srcu koja dovodi do infarkta miokarda (srčanog udara). Jedan od prvih događaja kod formiranja tromba je agregacija trombocita. IP6 smanjuje abnormalnu lepljivost (agregaciju) trombocita.
Prof. Giorgio Lambertenghi Deliliers i njegove kolege s Univerziteta u Milanu, Italija, objavili su u Britanskom časopisu za hematologiju [tom. 117: s. 577-587] u junu 2002. da je IP6 uzrokovao citotoksičnost zavisnu od doze na različitim ćelijskim linijama mijeloične leukemije kod ljudi, kao i kod novih progenitornih ćelija hronične mijeloične leukemije (CML); IP6, pak, nije imao toksične posledice po normalne ljudske hematopoetične ćelije kao što se obično viđa nakon standardnih hemoterapijskih agenasa. Autori zaključuju: “… spektar neoplazije na koji IP6 ima antiprofilerativno dejstvo može se proširiti na akutnu i hroničnu mijeloičnu leukemiju “.
IP6 + Inozitol kod dijabetesa
Eksperimenti s izolovanim beta ćelijama pankreasa miševa pokazali su da IP6 stimuliše te ćelije da luče insulin“ [Hoj i grupa autora, Časopis biološke hemije Tom: 278 #37 s. 35168-35171, 12. septembar 2003.]. A Dilvort i njegove kolege izvestili su da suplementacija IP6 uz prehranu snižava nivoe glukoze u krvi. Činjenicu da dijabetičari mogu imati koristi od IP6 + Inozitola još više su poduprli podaci Našimenta i njegovih kolega koji su 3. Januara 2006. u jednom od izdanja PNAS-a izvestili da u njihovom eksperimentalnom modelu sam inozitol može delovati kao antioksidans, i ne samo da sprečava, već i poništava mnoge komplikacije dijabetesa. Tako, s jedne strane, IP6 uzrokuje direktnu stimulaciju insulina u beta ćelijama pankreasa, a inozitol, s druge strane, pomaže u prevenciji komplikacija dijabetesa; kombinacija IP6 + Inozitola pruža dvostruku prednost.
Zaštita od zračenja od strane IP6 & Inozitola
Radijacija je energija distribuirana preko elektromagnetskog spektra. Oko 80% sve radijacije s kojom se susreću sisari potiče iz prirodno nastalih izvora. Izveštaj u časopisu Doziometrija zaštite od radijacije (2007.) dr D. Sebriana i kolega s Radiobiološke laboratorije Katedre za zaštitu životne sredine, CIEMAT, Madrid, Španija, pokazuje da “jak afinitet inozitola heksafosfata (IP6) prema uranijumu, sugeriše da inozitol može biti delotvoran helatni agens za uranijum in vivo.”
In vivo (kod laboratorijskih miševa) IP6 je značajno smanjio pojavu i mnogostrukost UV- indukovanih tumora kože. Ti podaci, dakle, sugerišu da IP6 + inozitol mogu da pomognu u zaštiti od raznih oblika štete koje nastaju radijacijom, poput štete od UV zračenja od izloženosti suncu, radijacije od zračenja, kosmičkog zračenja, slučajnih ili namerno izazvanih nuklearnih eksplozija, itd.
IP6 najpoznatiji je kao antioksidant, bez obzira što je poznat i kao “anti-nutrijent”. Visoko reaktivne toksične hemikalije u našem talu poput •OH (hidroksil radikala) nastale su kao posledica oksidacije Fe2+ to Fe3+ tokom reakcije Fe2+ s H2O2 posredstvom Fenton reakcije. Ovi radikali reaguju s DNK, proteinima ili lipidima i uzrokuju oštećenje ćelija, pa čak i ćelijsku smrt; inkriminisani su da uzrokuju sve, od Alchajmerove bolesti, raka, oštećenja miokarda tokom infarkta,itd.
Povezivanjem sa i deaktivacijom Fe2+, IP6 sprečava formiranje toksičnih •OH. Premda je oksidacija štetna za nas, nije ništa manje štetna za naše neprijatelje- mikrobe i rak. Ubijanje ćelija raka zračenjem dešava se posredstvom štete nastale oksidacijom, baš kao i uništavanje bakterija od strane naših ćelija “pešadinaca”, polimorfonuklearnih neutrofila. Kao i prilikom normalizacije proliferacije ćelija (videti dole), i ovde IP6, dok s jedne strane deluje kao antioksidans i štiti od štetnih slobodnih radikala, takođe povećava sposobnost tela za ubijanje invazivnih mikroba putem povećane proizvodnje superoksida unutar neutrofila!
Još jedan mehanizam dejstva IP6 i inozitola je inhibicija prekomernog i nekontrolisanog rasta ćelija (normalizacija) u uslovima bolesti, bez uticaja na stepen rasta normalnih ćelija. U veoma visokim dozama IP6 može ubiti ćelije raka, ali ne i normalne ćelije, po čemu se jasno razlikuje od većine antikancerogenih agensa.
Tokom preobražaja normalnih ćelija u maligne, ćelije raka gube normalne šablone ponašanja, i taj fenomen se zove dediferencijacija. Istovremeno, one takođe izgledaju drugačije: ćelije raka imaju veće telo (citoplazmu) i disproporcionalno veliko jedro, tj. povećanu razmeru jedro: citoplazma. Još jedan široko rasprostranjen mehanizam dejstva IP6 & Inozitola je preokretanje tog procesa ili vraćanje diferencijacije ćelija u normalu, tako da one počinju i da izgledaju kao normalne ćelije. Panel dat dole ilustruje i inhibiciju rasta ćelija i indukciju diferencijacije ćelijske linije mlečnih ćelija kod ljudi.
Na mikrofotografiji dole levo nalazi se puno MCF-7 humanih ćelija raka dojke (kontrola). Posledica lečenja IP6 je smanjenje broja ćelija raka kao i povećanje diferencijacije, kao što tamnosmeđom bojom (prikaz gore levo) predstavljena povećana proizvodnja laktalbumina- markera normalnih mlečnih ćelija epitela pokazuje.Trakasti grafikon prikazuje povećanje proizvodnje laktalbumina u skladu s povećanjem doze. Imajte u vidu da ne postoji dokaz ćelijske smrti (Istraživanje usmereno ka suzbijanju raka 1996.).
U toku su istraživanja koja nam pružaju nove podatke o načinima na koje IP6 modulira druge međućelijske regulatore poput p53, p27, PI-3 kinaze, NFκB, PKCδ, ppRb, Akt, ERK 1/2 itd. Ovo su neki od načina na koje IP6/Inozitol deluju. Za najnovije istraživačke radove, molimo vas posetite PubMed i ukucajte “ip6” ili “InsP6” ili “inozitol heksafosfat” ili “inozitol heksakisfosfat”
Koliko su bezbedni Inozitol i IP6?
I IP6 (kalcijum fitat) i inozitol nalaze se na listi GRAS (Generally Recognized as Safe – opšte priznatih bezbednih) supstanci sastavljenoj od strane američke Uprave za hranu i lekove (FDA); GRAS je oznaka FDA da stručnjaci smatraju hemikaliju ili supstancu koja se dodaje hrani bezbednom.
Naučnici koji se bave dejstvom IP6 i inozitola preporučuju korišćenje 2 kapsule dva puta dnevno (2 x 2) kao hemopreventiva dobrog zdravlje . Za one sa poznatim poteškoćama imunog sistema preporučuje 12 kapsula (3 x 4) dnevno . Da bi se postigla maksimalna korist IP – 6 Gold se najbolje uzima na prazan stomak.
Ovaj tekst i sajt su edukativnog karaktera, namenjeni za opšte obrazovanje i u informativne svrhe, nisu zamena za profesionalni medicinski savet, ispitivanje, dijagnozu ili lečenje.
Memorial Sloan–Kettering Cancer Center (MSKCC) – Čak i najveći i najstariji privatni centar za proučavanje raka u svetu, sa sedištem u New Yorku je priznao dokumentovano lekovita dejstva medicinskih gljiva.
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- Raina K, Ravichandran K, Rajamanickam S, et al. Inositol Hexaphosphate Inhibits Tumor Growth, Vascularity, and Metabolism in TRAMP Mice: A Multiparametric Magnetic Resonance Study. Cancer Prev Res (Phila). 2013 Jan;6(1):40-50.
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Inositol hexaphosphate (IP(6)) is a naturally occurring polyphosphorylated carbohydrate, abundantly present in many plant sources and in certain high-fiber diets, such as cereals and legumes. In addition to being found in plants, IP(6) is contained in almost all mammalian cells, although in much smaller amounts, where it is important in regulating vital cellular functions such as signal transduction, cell proliferation, and differentiation. For a long time IP(6) has been recognized as a natural antioxidant. Recently IP(6) has received much attention for its role in cancer prevention and control of experimental tumor growth, progression, and metastasis. In addition, IP(6) possesses other significant benefits for human health, such as the ability to enhance immune system, prevent pathological calcification and kidney stone formation, lower elevated serum cholesterol, and reduce pathological platelet activity. In this review we show the efficacy and discuss some of the molecular mechanisms that govern the action of this dietary agent. Exogenously administered IP(6) is rapidly taken up into cells and dephosphorylated to lower inositol phosphates, which further affect signal transduction pathways resulting in cell cycle arrest. A striking anticancer action of IP(6) was demonstrated in different experimental models. In addition to reducing cell proliferation, IP(6) also induces differentiation of malignant cells. Enhanced immunity and antioxidant properties also contribute to tumor cell destruction. Preliminary studies in humans show that IP(6) and inositol, the precursor molecule of IP(6), appear to enhance the anticancer effect of conventional chemotherapy, control cancer metastases, and improve quality of life. Because it is abundantly present in regular diet, efficiently absorbed from the gastrointestinal tract, and safe, IP(6) + inositol holds great promise in our strategies for cancer prevention and therapy. There is clearly enough evidence to justify the initiation of full-scale clinical trials in humans.
A significant anticancer activity of the naturally occurring carbohydrate inositol hexaphosphate (IP(6)) has been reported against numerous cancer models. Since tumors require angiogenesis for growth and metastasis, we hypothesize that IP(6) reduces tumor growth by inhibiting angiogenesis. Because angiogenesis depends on the interaction between endothelial and tumor cells, we investigated the effect of IP(6) on both. IP(6) inhibited the proliferation and induced the differentiation of endothelial cells in vitro; the growth of bovine aortic endothelial cells (BAECs) evaluated by MTT proliferation assay was inhibited in a dose-dependent manner (IC(50) = 0.74 mM). The combination of IP(6) and vasostatin, a calreticulin fragment with anti-angiogenic activity, was synergistically superior in growth inhibition than either compound. IP(6) inhibited human umbilical vein endothelial cell (HUVEC) tube formation (in vitro capillary differentiation) on a reconstituted extracellular matrix, Matrigel, and disrupted pre-formed tubes. IP(6) significantly reduced basic fibroblast growth factor (bFGF)-induced vessel formation (P < 0.01) in vivo in Matrigel plug assay. Exposure of HepG2, a human hepatoma cell line, to IP(6) for 8 h, resulted in a dose-dependent decrease in the mRNA levels of vascular endothelial growth factor (VEGF), as assessed by RT-PCR. IP(6) treatment of HepG2 cells for 24 h also significantly reduced the VEGF protein levels in conditioned medium, in a concentration-dependent manner (P = 0.012). Thus, IP(6) has an inhibitory effect on induced angiogenesis.
Inositol hexaphosphate IP6) inhibits key events of cancer metastasis: II. Effects on integrins and focal adhesions.
We have shown that inositol hexaphosphate (IP6), a natural compound and a potent anti-cancer agent, inhibited cancer cell adhesion to the extracellular matrix (ECM) proteins, thereby leading to inhibition of cell migration and invasion. Cell adhesion to ECM is mediated by specific cell surface integrins, which transduce intracellular signals through their interaction and activation of other proteins that are recruited to the focal adhesion. We hypothesize that IP6 decreases cell adhesion by suppressing the integrin receptors and their subsequent signaling pathway.
MATERIALS AND METHODS:
We analyzed integrin expressions of the highly invasive estrogen receptor-negative human breast cancer MDA-MB 231 cells exposed to IP6 by flow cytometry. The expression of focal adhesion proteins was investigated by immunocytochemistry and Western blotting.
IP6 treatment caused a significant (P < 0.005) decrease in the expression of integrin heterodimers alpha 2 beta 1 (collagen receptor), alpha 5 beta 1 (fibronectin receptor) and alpha v beta 3 (vitronectin receptor); flow cytometry showed that it was the alpha 5 subunit that was down-regulated ( < 0.001). However, the expression of the alpha 2, alpha v, beta 1 and beta 3 subunits were not affected by IP6 treatment. When the expression of integrins on the cell surface was assessed, there was a dramatic 82% decrease in the expression of alpha 5 beta 1 on IP6-treated cells (P < 0.0001), indicating a decrease in cell surface expression of the heterodimers. No effect was seen when inositol hexasulfate (IS6), an analogue of IP6, was used as a control. Immunocytochemistry showed a lack of clustering of paxillin; tyrosine-phosphorylated proteins in IP6-treated cells were discontinuous and scattered around the cell periphery, whereas the patterns were more dense and localized in control cells. Consistent with these observations, focal adhesion kinase (FAK) autophosphorylation at tyrosine-397 residue was suppressed, albeit modestly, by IP6 treatment, suggesting a down-regulation in the integrin-mediated signaling pathway.
The results of this study indicate that IP6-induced inhibition of cancer cell adhesion, migration and invasion may be mediated through the modulation of integrin dimerization, cell surface expression and integrin-associated signaling pathway.
- [PubMed – indexed for MEDLINE]
Inositol hexaphosphate (IP6) inhibits key events of cancer metastasis: I. In vitro studies of adhesion, migration and invasion of MDA-MB 231 human breast cancer cells.
The anti-cancer agent inositol hexaphosphate (IP6) is an abundant intrinsic component of both plant and mammalian cells. In addition to inducing differentiation and inhibiting growth of numerous cancer cell lines in vitro, IP6 has been demonstrated to prevent and abrogate both primary tumor and metastasis in vivo.
MATERIALS AND METHODS:
Using MDA-MB 231 human breast cancer cells, we studied the potential of IP6 to inhibit cell adhesion, migration and invasion, the key steps in cancer metastasis, utilizing the extracellular matrix (ECM) proteins, a culture wounding assay, modified Boyden chambers, immunocytochemistry and zymography.
IP6 treatment caused a 65% reduction of cell adhesion to fibronection (p = 0.002) and a 37% reduction to collagen (p = 0.005). To determine whether a decrease in cell adhesion leads to a decrease in cell motility, migration assays were performed; IP6 decreased both the number of migrating cells and the distance of cell migration into the denuded area by 72% (p < 0.001). Haptotatic cell migration in a modified Boyden chambers was also reduced in a dose-dependent manner. While cell migration on fibronectin was inhibited by 65% (p < 0.001), migration on collagen and laminin was decreased by 32% (p < 0.01) and 13% (p < 0.05), respectively. Immunocytochemistry revealed the absence of lamellipodia structure in IP6-treated cells as compared to untreated cells, corresponding to a diminished ability of cancer cells to form cellular network as determined by Matrigel outgrowth assay. Likewise, cell invasion also was decreased (by 72% after IP6 treatment, p = 0.001) in a dose-dependent fashion. Additionally, IP6 significantly (p = 0.006) inhibited the secretion of matrix metalloproteinase (MMP)-9 as assessed by zymography.
The results of this study show that IP6 inhibits the metastasis of human breast cancer cells in vitro through effects on cancer cell adhesion, migration and invasion.
- [PubMed – indexed for MEDLINE]
Inositol hexaphosphate (IP6) is a naturally occurring polyphosphorylated carbohydrate that is present in substantial amounts in almost all plant and mammalian cells. It was recently recognized to possess multiple biological functions. A striking anticancer effect of IP6 was demonstrated in different experimental models. Inositol is also a natural constituent possessing moderate anticancer activity. The most consistent and best anticancer results were obtained from the combination of IP6 plus inositol. In addition to reducing cell proliferation, IP6 increases differentiation of malignant cells, often resulting in a reversion to normal phenotype. Exogenously administered IP6 is rapidly taken into the cells and dephosphorylated to lower-phosphate inositol phosphates, which further interfere with signal transduction pathways and cell cycle arrest. Enhanced immunity and antioxidant properties can also contribute to tumor cell destruction. However, the molecular mechanisms underlying this anticancer action are not fully understood. Because it is abundantly present in regular diet, efficiently absorbed from the gastrointestinal tract, and safe, IP6 holds great promise in our strategies for the prevention and treatment of cancer. IP6 plus inositol enhances the anticancer effect of conventional chemotherapy, controls cancer metastases, and improves the quality of life, as shown in a pilot clinical trial. The data strongly argue for the use of IP6 plus inositol in our strategies for cancer prevention and treatment. However, the effectiveness and safety of IP6 plus inositol at therapeutic doses needs to be determined in phase I and phase II clinical trials in humans.
Inositol hexaphosphate (IP6) enhances the anti-proliferative effects of adriamycin and tamoxifen in breast cancer.
The current treatment of breast carcinomas recognizes the importance of combination therapy in order to increase efficacy and decrease side effects of conventional chemotherapy. Inositol hexaphosphate (IP6), a naturally occurring polyphosphorylated carbohydrate, has shown a significant anti-cancer effect in various in vivo and in vitro models, including breast cancer. In this study, we investigated the in vitro growth inhibitory activity of IP6 in combination with adriamycin or tamoxifen, against three human breast cancer cell lines: estrogen receptor (ER) alpha-positive MCF-7, ER alpha-negative MDA-MB 231 and adriamycin-resistant MCF-7 (MCF-7/Adr) using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Much lower concentrations of IP6 were required after 96 h of treatment to inhibit the growth of MCF-7/Adr cells than MCF-7 cells; the IC50 for MCF-7/Adr cells was 1.26 mM compared to 4.18 mM for MCF-7 cells. The ER-negative MDA-MB 231 cells were also highly sensitive to IP6 with IC50 being 1.32 mM. To determine the effects of IP6 in combination with either adriamycin or tamoxifen, the median effect principle and Webb’s fraction method were used to determine the combination index (CI) and the statistical differences. Growth suppression was markedly increased when IP6 was administered prior to the addition of adriamycin, especially against MCF-7 cells (CI = 0.175 and p < 0.0001). Synergism was also observed when IP6 was administered after tamoxifen in all three cell lines studied (CI = 0.343, 0.701 and 0.819; p < 0.0001, p = 0.0003 and 0.0241 for MCF-7/Adr, MCF-7 and MDA-MB 231, respectively). The growth of primary culture of breast cancer cells from patients was inhibited by IP6 with LC50 values ranging from 0.91 to 5.75 mM (n = 10). Our data not only confirm that IP6 alone inhibits the growth of breast cancer cells; but it also acts synergistically with adriamycin or tamoxifen, being particularly effective against ER alpha-negative cells and adriamycin-resistant cell lines.
- [PubMed – indexed for MEDLINE]
Inositol hexaphosphate (InsP6 or IP6) has shown a striking anti-cancer activity in both in vivo and in vitro models. In an attempt to elucidate the mechanism(s) underlying the anti-neoplastic potential of IP6, we investigated its effect on cell cycle progression of MCF-7 estrogen receptor (ER)-positive and MDA-MB 231 ER-negative human breast cancer cell lines and HT-29 human colon cancer cells.
The anti-proliferative effect of IP6 was evaluated using dual-parameter flow cytometric measurements of DNA content, versus the incorporation of 5-bromo-2-deoxyuridine (BrdU) to determine cells actively synthesizing DNA. Combined analysis of the expression of cell cycle-related proteins, proliferation marker Ki-67 and proliferating cell nuclear antigen (PCNA) versus DNA content were used to determine the amount of proliferating cells in each phase, engaged in cell cycle transit.
After 3 days of treatment with 5 mM IP6, S-phase, as estimated by BrdU uptake, was significantly decreased in all three cell lines (p = 0.002). MCF-7 and HT-29 cells accumulated in the G0/G1 range of DNA contents (p = 0.002 and p = 0.001, respectively). MDA MB-231 cells transiently accumulated in G0/G1 only after 2 days (p = 0.01). There was a significant decrease in the percentage of Ki-67 expression in IP6-treated cells, from 82.8+/-3.0% to 66.8+/-4.2% in MCF-7 (p = 0.007), from 93.4+/-4.6% to 71.7+/-3.3% in MDA-MB 231 (p = 0.004), and from 95.2+/-1.2% to 73.5+/-2.5% in HT-29 cells (p = 0.002) respectively. PCNA expression levels were also significantly decreased by IP6 in all three cell lines (MCF-7 p = 0.0007; MDA-MB 231 p = 0.0006; HT-29 p = 0.0001).
These results show that IP6 controls the progression of cells through the cycle by decreasing S- phase and arresting cells in the G0/G1-phase of the cell cycle. A significant decrease in the expression of proliferation markers indicated that IP6 disengaged cells from actively cycling. Further investigations of cell cycle regulators may lead us to a better understanding of the mechanism(s) of the anti-neoplastic action of IP6.
- [PubMed – indexed for MEDLINE]
Inositol hexaphosphate, a natural substance found in whole kernel corn and brown rice, activates natural killer cell function – inhibits cancer.
- [PubMed – indexed for MEDLINE]
A two-stage mouse skin carcinogenesis model was used to examine the effects of IP6 on initiation and promotion phases of tumorigenesis. Seven week old ICR female mice were divided into 6 groups, each consisting of 20 animals. Initiation was performed by a single application of the carcinogen 7,12-dimethyl benz(a)anthracene (DMBA) (50 micrograms) to the back skin. Three weeks later, local application of the promoter TPA was started (2.5 micrograms, 2 x/week) and continued up to the end of the experiment (22 weeks). Mice were also administered 2% IP6 in drinking water over the entire duration of the experiment, or during the initiation (initial 3 weeks) or promotion (final 19 weeks) periods only. The animals consuming IP6 during the initiation stage showed an approximately 50% reduction in the mean number of papillomas per animal, as well as in the number of tumor bearing mice. However, no such inhibition was observed when IP6 was given during the tumor promotion stage. In a separate experiment the effects of IP6 on epithelial cell growth were assessed by BrdU labeling at several time points. Statistically significant inhibition of cell proliferation was observed during the initiation stage (one week after DMBA treatment) in the group given IP6. No inhibition was evident during the promotion stage.
- [PubMed – indexed for MEDLINE]
Inositol hexaphosphate (IP6) has a demonstrably effective anti-cancer action against a variety of experimental tumors. However, the mechanisms of its actions are yet to be completely discerned. Studies in my laboratory have shown that IP6 is rather rapidly absorbed by rats in vivo. Ion exchange chromatography demonstrates the presence of inositol and IP1-6 in gastric epithelial cells as early as within 1 h of intragastric 3H-IP6 administration. The metabolized IP6, in the form of inositol and IP1 is transported via plasma and reaches distant organs as well as tumors. In rats, the urinary metabolites of IP6 are inositol and IP1. However, in humans 1-3% of total administered IP6 is excreted in the urine as IP6; the level shows a normal oscillation between 0.5-6 mg/L [F. Grases et al]. Investigations of the uptake and metabolism by a variety of cancer cell lines in vitro also demonstrate an instantaneous absorption of IP6. The rate and pattern at which IP6 is metabolized by cancer cells varies depending on the cell type. Intracellular inositols accumulated mostly (80-97%) in the cytosol as inositol and IP1-6. IP6 treatment of all the cell lines tested so far demonstrates that it is cytostatic and not cytotoxic. Along with inhibition of cell proliferation, there is enhanced differentiation of malignant cells to a more mature phenotype, often resulting in reversion to normal. Studies of the expression of tumor suppressor gene demonstrate up-regulation of wild type p53 and down-regulation of the mutant form. Since p53-mediated cell cycle arrest may be the direct result of induction of WAF-1 gene (p21WAF-1/CIP1), our studies demonstrate that IP6 up-regulates the expression of p21WAF-1/CIP1 in a dose-dependent manner. These data strongly point towards the involvement of signal transduction pathways, cell cycle regulatory genes, differentiation genes, oncogenes and perhaps, tumor suppressor genes in bringing about the observed anti-neoplastic action of IP6.
- [PubMed – indexed for MEDLINE]
Platelet adhesion to endothelial cells, their aggregation and subsequent release of platelet-derived mediators are key steps in the pathogenesis of thrombosis and atherosclerosis. Using impedance technology the effect of inositol hexaphosphate (IP6) on platelet aggregation and adenosine triphosphate (ATP) release were simultaneously measured in whole blood obtained from healthy volunteers (n = 10). The platelets were activated with adenosine diphosphate (ADP) (10 microM), collagen (2 micrograms/mL), or thrombin (1 U/mL) in the presence or absence of IP6. IP6 significantly inhibited platelet aggregation induced with all agonists in a dose-response manner (p < 0.0001 for ADP and collagen, p = 0.0103 for thrombin), with the IC50 values of 0.9, 1.6 and 0.8 mM. Secretion of platelet dense granule content was measured in parallel. IP6 strongly and significantly reduced agonist-induced ATP release (p = 0.00247 for ADP; p = 0.0074 for collagen; p = 0.0069 for thrombin). These data demonstrate that IP6 effectively inhibits human platelet aggregation in vitro, suggesting its potential in reducing the risk for cardiovascular disease.
- [PubMed – indexed for MEDLINE]
While most studies of diet and breast cancer are focused on the role of fat, very few have addressed the effect of fiber. Emerging epidemiological data, and careful review of previous studies point to a negative correlation of breast cancer with high fiber cereal diets. Inositol hexaphosphate (IP6) is abundant in cereals and legumes, particularly in the bran part of mature seeds. Experimental studies using 7,12-dimethylbenz [alpha]anthracene (DMBA) and N-methylnitrosourea (NMU) in rats and mice in vivo, as well as human cell lines in vitro demonstrate a reproducible and striking anti-cancer action of IP6. It therefore appears that IP6 is one of the components, if not the most active ingredient, of high fiber cereal diet responsible for cancer inhibition. Could eating high fiber diet afford the same protection as IP6? Thus, we investigated whether dietary fiber containing high IP6 shows a dose-response inhibition of DMBA-induced rat mammary carcinogenesis, and if pure IP6 is more active as a cancer preventive agent, compared to that in diet. Our data show that supplemental dietary fiber in the form of bran exhibited a modest, statistically nonsignificant inhibitory effect. In contrast, animals given IP6 in drink showed significant reduction in tumor number, incidence and multiplicity. Therefore, pure IP6 is definitively more effective than a high fiber diet in preventing experimental mammary tumors. Thus, for cancer prevention, prophylactic intake of IP6 may be not only more effective, but also more practical than gorging on large quantities of fiber.
- [PubMed – indexed for MEDLINE]
IP6 in treatment of liver cancer. II. Intra-tumoral injection of IP6 regresses pre-existing human liver cancer xenotransplanted in nude mice.
Hepatocellular carcinoma (HCC) is a deadly malignant disease with extremely poor prognosis. Many therapeutic modalities have been proposed, but considerable uncertainty still remains about their effectiveness. Inositol hexaphosphate (IP6), a naturally occurring polyphosphorylated carbohydrate, has novel anti-cancer function both in vitro and in vivo. We have recently demonstrated that IP6 inhibits HepG2 human liver cancer cell line. The aim of this study was to assess whether IP6 can (a) inhibit tumorigenicity, and (b) suppress or regress the growth of HepG2 cells in a transplanted nude mouse model. To test the inhibition of tumorigenicity, HepG2 cells were treated with a single exposure to 5.0 mM IP6 in vitro; 48 h later they were inoculated (1 x 10(7) cells/mouse) subcutaneously. No tumor was found in mice which had received HepG2 cells pretreated with IP6 whereas 71% of mice receiving the same number of control untreated HepG2 cells developed solid tumors at the transplantation site (p < 0.03). For a tumor suppression/regression study, when the transplanted tumors reached 8-10 mm in diameter, intra-tumoral injection of IP6 (40 mg/kg) was given for 12 consecutive days, after which the animals were sacrificed. At autopsy, the tumor weight in IP6-treated mice was 86% to 1180% (340% average) less than that in control mice (0.33 +/- 0.12 g versus 1.13 +/- 0.25 g, p = 0.016). These data show that IP6 inhibits the formation of liver cancer and regresses pre-existing human hepatic cancer xenograft; therefore, it has the potential for clinical use as a preventive and therapeutic agent for hepatocellular carcinoma as well.
- [PubMed – indexed for MEDLINE]
IP6 in treatment of liver cancer. I. IP6 inhibits growth and reverses transformed phenotype in HepG2 human liver cancer cell line.
Hepatocellular carcinoma (HCC) is a common tumor world-wide with extremely poor prognosis. Recent studies have shown that inositol hexaphosphate (IP6), a naturally occurring carbohydrate, has novel anti-cancer function in various in vitro and in vivo models. The aim of this study was to assess whether IP6 could inhibit the growth of human hepatocellular carcinoma. We treated HepG2, a human liver cancer cell line in vitro with IP6 and evaluated its effect on growth and differentiation. IP6 treatment of HepG2 cells caused a dose-dependent growth inhibition. Compared to other cancer cell lines, HepG2 cells were quite sensitive to IP6, IC50 (50% inhibition of cell growth) of IP6 being < 1.0 mM (0.338 mM). Treatment with IP6 decreased the ability of HepG2 cells to form colonies, as assessed in the plating efficiency assay. Morphological changes induced by IP6 were consistent with differentiation of HepG2 cells. Exposure of HepG2 cells to IP6 drastically decreased the rate of production of alpha-fetoprotein (AFP), a tumor marker of HCC, indicating also that IP6 treatment leads to differentiation of malignant liver cells. Further, IP6 treatment caused a decreased expression of mutant p53 protein in HepG2 cells, with no significant change in the expression of wild-type p53. The expression of p21WAF1 protein was increased by 1.5 fold, as determined by immunocytochemical staining and ELISA assay. These data demonstrate that IP6 inhibits the growth, and induces differentiation, and a less aggressive phenotype of HepG2 cells, suggesting a role of IP6 in the treatment of HCC.
- [PubMed – indexed for MEDLINE]
Up-regulation of the tumor suppressor gene p53 and WAF1 gene expression by IP6 in HT-29 human colon carcinoma cell line.
Inositol hexaphosphate (InsP6 or IP6) ubiquitous in various cells has a novel anti-cancer action both in vivo and in vitro. IP6 inhibits cell growth, decreases cell proliferation and also causes differentiation of various cell lines, including HT-29 human colon carcinoma cell. We hypothesize that the tumor suppressor genes such as p53 and WAF1/CIP1 may be involved in mediating the anti-neoplastic action of IP6 p53 acts as a molecular policeman prevention of genetically damaged cells; it causes the cells to arrest in the G1 phase of cell cycle, and regulates the level of p21waf1/cip1 which acts as a growth inhibitor. We therefore investigated the effects of IP6 on the expression of p53 and WAF1/p21 in HT-29 human colon carcinoma by immunocytochemistry and quantitative ELISA. Our immunocytochemical studies with anti p53 antibodies (wild type-PAb246 and PAb1620) and anti p21waf1/cip1 (EA10) antibodies demonstrated an increased level of p53 and p21waf1/cip1 after 3 and 6 days of treatment with 3.3 and 5 mM IP6. Quantitative assay for p53 and p21waf1/cip1 by ELISA did not show detectable levels in untreated control cells, while strong expression of p53 and p21waf1/cip1 protein by 3.3 and 5 mM IP6 was seen on day 3 and day 6 of treatment. This increase was dose-dependent; however, a definite time-dependent increase was not observed. These data demonstrate that IP6 up-regulates the expression of the tumor suppressor gene p53 and p21WAF1/CIP1 gene and their modulation may be one of the mechanisms of the anti-neoplastic action of IP6. Since loss of p53 function enhances cancer cells’ resistance to chemotherapeutic agents, the stimulating function of IP6 on p53 makes it an attractive adjuvant chemotherapeutic agent as well.
- [PubMed – indexed for MEDLINE]
Novel anticancer function of inositol hexaphosphate: inhibition of human rhabdomyosarcoma in vitro and in vivo.
Inositol hexaphosphate (IP6) is a naturally occurring polyphosphorylated carbohydrate that has been shown to suppress the growth of epithelial cancers, including those of breast and colon. The objective of this study was to investigate whether IP6 inhibits growth of rhabdomyosarcoma (RMS), a tumor of mesenchymal origin, which is the most common soft tissue sarcoma in children. We performed both in vitro and in vivo studies to evaluate the effect of IP6 on human RD cells growth. Our results show that IP6 suppresses growth of rhabdomyosarcoma cell line (RD) in vitro in a dose-dependent fashion. A 50% inhibition of cell growth (IC50) was induced by < 1.0 mM IP6. However, the removal of IP6 from the media, after 72 hours of treatment, allowed cells to recover their logarithmic growth. Exposure of RD cells to IP6 led to differentiation; cells became larger with abundant cytoplasm, expressing higher levels of muscle-specific actin. Consistent with in vitro observation, IP6 suppressed RD cell growth in vivo, in a xenografted nude mice model. When compared to controls, IP6-treated mice produced a 25 fold smaller tumors (p = 0.008), as observed after a two weeks treatment. In a second experiment, wherein the treatment period was extended to five weeks, a 49 fold (p = 0.001) reduction in tumor size was observed in mice treated with IP6. Histologically no evidence of tumor cell necrosis was observed. These data suggest a potential usefulness of this cytostatic, and non-cytotoxic, compound in novel therapeutic strategies for these types of tumor.
- [PubMed – indexed for MEDLINE]
Inositol hexaphosphate (InsP6 or IP6) is ubiquitous. At 10 microM to 1 mM concentrations, IP6 and its lower phosphorylated forms (IP(1-5)) as well as inositol (Ins) are contained in most mammalian cells, wherein they are important in regulating vital cellular functions such as signal transduction, cell proliferation and differentiation. A striking anti-cancer action of IP6 has been demonstrated both in vivo and in vitro, which is based on the hypotheses that exogenously administered IP6 may be internalized, dephosphorylated to IP(1-5), and inhibit cell growth. There is additional evidence that Ins alone may further enhance the anti-cancer effect of IP6. Besides decreasing cellular proliferation, IP6 also causes differentiation of malignant cells often resulting in a reversion to normal phenotype. These data strongly point towards the involvement of signal transduction pathways, cell cycle regulatory genes, differentiation genes, oncogenes and perhaps, tumor suppressor genes in bringing about the observed anti-neoplastic action of IP6.
Comparison of pure inositol hexaphosphate and high-bran diet in the prevention of DMBA-induced rat mammary carcinogenesis.
Inositol hexaphosphate (IP6), abundant in cereals and legumes, has been demonstrated to be a promising anticancer agent in different in vivo and in vitro models. Because IP6 is particularly abundant in the bran part of certain mature seeds such as wheat, we investigated whether a high-fiber bran diet containing high IP6 shows a dose-response inhibition of 7,12-dimethylbenz[a]anthracene (DMBA)-induced rat mammary carcinogenesis. Starting at two weeks before DMBA intubation, rats were divided into five groups and fed AIN-76A diet only or AIN-76A diet containing 5%, 10%, or 20% Kelloggs’ All Bran; the fifth group received 0.4% IP6 given in drinking water, an amount equivalent to the IP6 content in 20% bran. After carcinogen administration, the rats remained on these regimens for 29 weeks. Compared with the carcinogen control, at 29th week, tumor incidence was reduced by 16.7%, 14.6%, and 11.4% in rats fed 5%, 10%, and 20% bran, respectively (not statistically significant). However, rats given 0.4% IP6 in drinking water, equivalent to that in 20% bran, had a 33.5% reduction in tumor incidence (p < 0.02) and 48.8% fewer tumors (p < 0.03). These data show that supplemental dietary fiber in the form of bran exhibited a very modest, statistically nonsignificant inhibitory effect, which was also not dose dependent. In contrast, animals given IP6 showed significant reduction in tumor number, incidence, and multiplicity. Thus IP6 an active substance responsible for cereal’s beneficial anticancer effect, is clearly more effective than 20% bran in the diet. In practical terms, intake of IP6 may be a more pragmatic approach than gorging enormous quantities of fiber for cancer prophylaxis.
Novel anti-cancer functions of IP6: growth inhibition and differentiation of human mammary cancer cell lines in vitro.
Inositol hexaphosphate (InsP6 or IP6) is an active ingredient of high fiber diet that has anti-cancer action in both in vitro and in vivo models. Recently we have demonstrated that InsP6 significantly inhibits DMBA-induced rat mammary cancer in vivo. To test the hypothesis that InsP6 mediates its function via inhibition of cell proliferation irrespective of hormonal dependence, its effect on growth inhibition and differentiation were studied in two human mammary carcinoma cell lines with different estrogen receptor status. Cell growth was measured by MTT incorporation assay, DNA synthesis by 3H-Tdr uptake and differentiation marker lactalbumin by immunocytochemistry. Dose-dependent growth inhibition was observed in both estrogen receptor-positive (MCF-7) and receptor-negative cells (MDA-MB-231). Statistically significant growth inhibition (p < 0.05) was observed starting at 1 mM InsP6 as early as after the first day of treatment and continued up to 6 days for both the cell lines. DNA synthesis in both the cell lines was suppressed by InsP6 occurring as early as 3 h after the beginning of treatment and continued up to 48 h; significant inhibition (p < 0.05) started at 1 mM InsP6 after 6 h of treatment. Compared to untreated cells, a 5-fold (p < 0.05) and 22-fold (p < 0.01) increase in expression of lactalbumin, associated with luminal cell differentiation was identified by immunocytochemistry after 48 h of treatment with 1 and 5 mM InsP6. Our data show that the inhibition of DNA synthesis and cell growth and induction of differentiation of human mammary cancer cell lines by InsP6 is independent of the estrogen receptor status of the cells. Taken together with results from in vivo studies, InsP6 may be an important candidate for the prevention and treatment of human breast cancer.
- [PubMed – indexed for MEDLINE]
IP6-induced growth inhibition and differentiation of HT-29 human colon cancer cells: involvement of intracellular inositol phosphates.
Inositol hexaphosphate (InsP6 or IP6) ubiquitous in plants and animals is not only a natural antioxidant, but may also be the precursor/storage of intracellular inositol phosphates, important for various cellular functions. A novel anti-tumor action of InsP6 was demonstrated in models of experimental colon and mammary carcinogenesis in vivo. We now show its effects on growth and differentiation of HT-29 human colon carcinoma cells in vitro. A dose- and time-dependent (0.33-20 mM InsP6 and 1-6 days treatment) growth inhibition was observed as tested by MTT- incorporation assay. The inhibition was statistically significant (p < 0.05) at 1 mM concentration as early as first day after treatment and continued up to 6 days. DNA-synthesis was also suppressed by InsP6 and significantly inhibited as early as 6 h after treatment at 1 mM concentration (p < 0.05) and continued to 48 h (p < 0.01). The expression of proliferation marker PCNA was down-regulated (p < 0.05) by InsP6 (1 and 5 mM) after 48 h of treatment. To investigate the mechanism of action of InsP6 the intracellular phosphatases (including phytase) were inhibited by F to slow down the dephosphorylation of InsP6. Ion-exchange chromatographic separation of intracellular inositol phosphates demonstrated a 84-98% decrease of Ins, InsP1 and InsP2 InsP3 was reduced by 39% and InsP4 and InsP5 by 21% and 13% respectively, whereas intracellular InsP6 was increased by 24.6% at 5 min following 3H-InsP6. Since neither the rate of uptake of 3H-InsP6 was unaffected, nor was the efficacy of growth inhibition altered by F inhibition of phytase, data suggest that contrary to the popular misconception, phytase plays no role in influencing the anti-neoplastic action of InsP6. Alkaline phosphatase activity (brush border enzyme, associated with absorptive cell differentiation), increased following 1 and 5 mM InsP6 treatment for 1-6 days. The expression of a mucin antigen associated with goblet cell differentiation and defined by the monoclonal antibody CMU10 was augmented (p < 0.0001) by InsP6. The tumor mucin marker Gal-GalNAc, expressed by precancer and cancer of colon, but not by the normal cells showed a time-dependent biphasic change by InsP6; an increased expression after 1 day of treatment followed by suppression after 2 days suggest progression of mucin synthesis and differentiation of cancer cells with reversion to normal phenotype. Because the tumor marker Gal-GalNAc is a) easily detected in rectal mucin of patients with colonic cancer and precancer with high sensitivity and specificity, and b) suppressed by InsP6 treatment, it can be used to monitor the efficacy of chemoprevention by InsP6 or other such agents. Since InsP6 a natúral dietary ingredient of cereals and legumes, inhibits growth and induces terminal differentiation of HT-29 cancer cells, it is an excellent candidate for adjuvant chemotherapy and prevention of cancer.
- [PubMed – indexed for MEDLINE]
Epidemiological data demonstrate correlations between dietary factors and the incidence of large intestinal cancer (LIC). Certain high-fiber diets are associated with a lower risk of LIC; these high-fiber diets are also rich in inositol hexaphosphate (IP6 or phytic acid). In a pilot study, we have used F344 rats to investigate the effect of sodium inositol hexaphosphate (Na-IP6) prior to (experiment I) and following injections of the carcinogen azoxymethane (AOM) (experiment II). In experiment I, rats started on 1% Na-IP6 in drinking water 1 week prior to the carcinogen treatment showed a 34.7% decrease (P less than 0.01) in LIC compared to control carcinogen treatment group. A similar reduction in the incidence of LIC was also observed in experiment II, wherein Na-IP6 supplementation was started 2 weeks following the last dose of the carcinogen. Comparison of the incidence of mitosis in the colonic crypts of the animals in different groups show that animals on AOM + IP6 demonstrate a significantly lower (P less than 0.001) mitotic rate than those receiving AOM only. Pilot studies of free radical generation demonstrate a reduction in .OH radical formation by Na-IP6. Further studies to expand this pilot data and to understand the mechanism of IP6 mediated LIC suppression are needed for it may have significance in our strategies for LIC control.
- [PubMed – indexed for MEDLINE]