Natural dietary agents can protect against DMBA genotoxicity in lymphocytes as revealed by single cell gel electrophoresis assay.

Many natural agents including fruits and vegetables are known to provide protection from different degenerative diseases including cancer, by preventing damage to the cellular components. The effect of two important dietary agents, alpha tocopherol, and the flavonoid quercetin, along with two commonly consumed vegetables, bitter gourd and tomato, were investigated on spontaneous and dimethylbenz(a)anthracene (DMBA)-induced DNA damage in murine lymphocytes in vitro. DNA damage was determined by single cell gel electrophoresis (comet assay). The rationale for such an approach for this study is that DNA damage can lead to genetic disorders that occur at different stages of carcinogenesis and protection from such damages may in the long run help to prevent development of cancer. Both alpha tocopherol and quercetin as single agents were found to be potent inhibitors of DNA damage (spontaneous and carcinogen induced) in a dose-dependent manner. Fresh juices of bitter gourd and tomato could also protect from DMBA-induced DNA damage but not as effectively as the single agents. The anticarcinogenic role of nutrients as well as non-nutrient dietary components need to be explored more extensively. The Comet assay is a simple, fast, and reliable method to determine the protective effect against DNA damage, one of the prerequisites for carcinogenesis. Copyright 2003 Wiley-Liss, Inc.