title: The vitamin C:vitamin K3 system - enhancers and inhibitors of the anticancer effect.
abstract: The oxidizing anticancer system of vitamin C and vitamin K₃ (VC:VK₃, producing hydrogen peroxide via superoxide) was combined individually with melatonin, curcumin, quercetin, or cholecalciferol (VD₃) to determine interactions. Substrates were LNCaP and PC-3 prostate cancer cell lines. Three of the tested antioxidants displayed differences in cell line cytotoxicity. Melatonin combined with VC:VK₃ quenched the oxidizing effect, while VC:VK₃ applied 24 hours after melatonin showed no quenching. With increasing curcumin concentrations, an apparent combined effect of VC:VK₃ and curcumin occurred in LNCaP cells, but not PC-3 cells. Quercetin alone was cytotoxic on both cell lines, but demonstrated an additional 50-percent cytotoxicity on PC-3 cells when combined with VC:VK₃. VD₃ was effective against both cell lines, with more effect on PC-3. This effect was negated on LNCaP cells with the addition of VC:VK₃. In conclusion, a natural antioxidant can enhance or decrease the cytotoxicity of an oxidizing anticancer system in vitro, but generalizations about antioxidants cannot be made.
authors.affiliation: Bastyr University, Kenmore, WA, USA. davisl@seanet.com
authors.forename: Davis W
authors.initials: DW
authors.lastname: Lamson
authors.forename: Yu-Huan
authors.initials: YH
authors.lastname: Gu
authors.forename: Steven M
authors.initials: SM
authors.lastname: Plaza
authors.forename: Matthew S
authors.initials: MS
authors.lastname: Brignall
authors.forename: Cathy A
authors.initials: CA
authors.lastname: Brinton
authors.forename: Angela E
authors.initials: AE
authors.lastname: Sadlon
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D000975:Antioxidants / Q000494:pharmacology*; D001205:Ascorbic Acid / Q000494:pharmacology*; D002453:Cell Cycle / Q000187:drug effects; D002762:Cholecalciferol / Q000494:pharmacology; D003474:Curcumin / Q000494:pharmacology; D003603:Cytotoxins / Q000494:pharmacology*; D004347:Drug Interactions; D004359:Drug Therapy, Combination; D006801:Humans; D008297:Male; D008550:Melatonin / Q000494:pharmacology; D018384:Oxidative Stress / Q000187:drug effects; D011471:Prostatic Neoplasms / Q000188:drug therapy*; D011794:Quercetin / Q000494:pharmacology; D014407:Tumor Cells, Cultured; D024483:Vitamin K 3 / Q000494:pharmacology*
chemical_list: D000970:Antineoplastic Agents; D000975:Antioxidants; D003603:Cytotoxins; D002762:Cholecalciferol; D024483:Vitamin K 3; D011794:Quercetin; D003474:Curcumin; D008550:Melatonin; D001205:Ascorbic Acid