University of Siena | Italy
Title: The anticancer properties of Vitamin C: In vitro update
Biography: Domenico Mastrangelo
Background: Vitamin C (ascorbic acid) is an essential nutrient with a number of beneficial functions, for the organism, among which it is worth mentioning its antioxidant activity and its role in the synthesis and stabilization of collagen. The anticancer/anti leukemic properties of Vitamin C are also known since at least 1969, even though the interest in Vitamin C as a potential anticancer molecule has only recently revived, thanks to experiments performed on human tumour cell lines in vitro.
Material and Methods: We used human tumour cell lines derived from retinoblastoma (Y79), uveal melanoma (C918, and OCM1) and human myeloid leukaemia (HL60, K562, U937, NB4, Nb4-R1, and NB4/As) exposed to different concentrations (in the order of magnitude of the millimoles) of the sodium salt of Vitamin C (sodium ascorbate). To evaluate cell viability before and after exposure to Vitamin C (sodium ascorbate), we used a standard flow cytometer and morphological/cytochemical methods, to further characterize the biological events produced by the exposure to the nutrient.
Results: All the cells used in our experiments showed apoptosis, autophagy, autoschizis, and still other forms of cell death degeneration after 1-2 hours exposure to millimolar concentrations of Vitamin C (sodium ascorbate). The apoptotic/cytotoxic effect of Vitamin C showed a peak at around 3 millimoles although Y79 cell lines appeared to be more sensitive than the rest of the cell lines tested.
Discussion: There are at least seven different pathways, through which Vitamin C in high concentration may be cytotoxic for cancer cells. The most commonly accepted cause of cell death, after exposure to millimolar concentrations of Vitamin C is considered the production of H2O2, consequent to the oxidation of the nutrient to dehydroascorbate (DHAA) and subsequent reduction to ascorbate, but other mechanisms, such as the downregulation of hypoxia inducible factor (HIF) are also involved.
In this experience with a variety of human tumour cell lines, we have showed that Vitamin C kills very efficiently different cancer cell, in vitro, being, at the same time, completely harmless for normal cells. The data reported herein imply that Vitamin C in high concentrations, such as those that can be reached by intravenous injection of the nutrient, represents a very promising, natural molecule in the routine treatment of different cancers.