Evaluation of bioflavonoids as potential chemotherapeutic agents

Bioflavonoids are compounds that are natural plant antioxidants. Antioxidants have been shown to prevent damage caused by free radicals to DNA and other molecules. Bioflavonoids have demonstrated several cancer preventive properties. In addition to antioxidant activity, these compounds may reduce abnormal cell growth and inflammation; help the body get rid of cancer-causing agents; and restore communication between different cells in the body. The objective of this study is to compare nontoxic phenols as cancer chemotherapeutic, agents and to apply these agents in treating human cancers. In this study the effects of a single dose of 10 microM Green Tea Extract (EGCG), 5 microM Tannic Acid (TA), or 5 microM Thymoquinone (TQ) on Hep-2 cells were determined. Compounds were evaluated in their effectiveness to reduce cell number. The cells were also evaluated for membrane damage, and alterations in cellular morphology after 24, 48, and 72 hours in culture. The results showed a 50% reduction in Hep-2 cell numbers after 24 hours in TQ treated cells. After 48 hours, the cells treated with TQ and TA exhibited a four-fold decrease in total cell number compared to the control and EGCG treated cells. Cell numbers were similar in all treatment groups by 72 hours. At 48 hours the only significant increase in cell damage was seen in cells treated with EGCG. The results indicated that naturally occurring bioflavonoids given in a bolus dose could alter cellular viability. It appears the drug is either utilized by the cells or chemically degraded in the media leading to increased cell numbers back toward control values with time in culture. In order for the compounds to be effective chemotherapeutic agents, the data also suggests a need for continuous administration over bolus dosing.