Free radical-dependent suppression of growth of mouse myeloma cells by alpha linolenic acid and eicosapentaenoic acids in vitro.
Free radical-dependent suppression of growth of mouse myeloma cells by alpha linolenic acid and eicosapentaenoic acids in vitro.
Year: 1995
Authors: G S Kumar, U N Das,
Publication Name: Cancer Lett.
Publication Details: Volume 92; 27.
Abstract:
Previous work by these investigators has demonstrated significant anticarcinogenic effects of EFA in tumor cells. Cis PUFAs including ALA, AA, EPA and DHA have been reported to selectively kill tumor cells in vitro. These PUFAs appear to act by increasing free radical and super?oxidase generation, and lipid peroxidation in tumor cells. It has been hypothesized that these products may cause damage to the DNA of the tumour cells and result in a regression in tumor growth. In order to expand their findings, the objective of the present study was to determine the effects of cis PUFAs on their ability to damage DNA and to alter the antioxidant system of tumor cells in vitro. A mouse myeloma cell line was cultured with several fatty acids including oleic, ALA, EPA, DHA, GLA and DGLA. Free radicals, lipid peroxidation products and damage to DNA were measured and compared to control cells with added LA. Of the PUFA tested, ALA and EPA exhibited the most potent cytotoxic effects. Antioxidants such as Vitamin E and superoxidase dismutase (SOD) were reported to inhibit the action of ALA and EPA suggesting that the anti-carcinogenic effects of these EFA is partly due to free radical and oxidative mechanisms. Both ALA and EPA enhanced the generation of free radicals and lipid peroxidation products as well as induced significant damage to tumor cell DNA. Research has shown that lipid peroxides disrupt the cell membrane and induce DNA-protein cross links contributing to the death of the cell. The tumor specific action of cis PUFAs may be associated with the observation that tumor cells have decreased activity of some antioxidant enzymes such as SOD. Similar results have been noted in human leukemic B and T cells. The authors concluded that ALA and EPA inhibit anti-oxidant defenses of cancer cells and disrupt their DNA, which can ultimately lead to tumor cell lysis and death.
