Correlation Between Total Phenols Content, Antioxidant Power and Cytotoxicity

Abstract

Plants are commonly used in traditional medicines against diseases according to their cytotoxic effect. Therefore, studying the relationship between antioxidant activity and cytotoxicity is remaining interesting to find a simple indicator for plant cytotoxicity. The objective of this study is to give scientific evidence of the correlation between antioxidant activity and cytotoxicity in 10 different plants. Phytochemical screening of 70% ethanolic extracts (EEs) has been shown to be rich in steroids, terpenoids, flavonoids, tannins, and phenols. The antioxidant activity of EEs gave IC50 ranged between 42.33 (Ipomoea batatas) and 1,519.76 μg ml-1 (Citrullus colocynthis) by DPPH method and 31.60 (Avicennia marina) and 1,133.79 μg ml-1 (Cichorium endivia L.) by ABTS method. The total phenolic content of EEs was ranged between 8.72 ± 0.08 (Daucus carota L.) and 91.67 ± 0.13 (Avicennia marina) as mg GAE g-1 dried sample. The Pearson’s correlation coefficient (r) between antioxidant activity (IC50) as related to total phenolic content was strongly correlated, moderately correlated with brine shrimp cytotoxicity, weakly correlated with carcinogenic liver and breast cells cytotoxicity, and weakly or moderately correlated with antimicrobial activity. These results proved that the total phenolic content could be indicating the antioxidant scavenging activity but not the cytotoxic effect.