Thesis (Ph.D.) - Cairo University - Faculty of Agriculture - Department of Agricultural Biochemistry

Plants are commonly used in traditional medicines against number of diseases according to its cytotoxic effect. Therefore, studying the relation between antioxidant activity and cytotoxicity is remaining interesting to find a simple indicator for plant cytotoxicity. Moreover, the nanoparticle of bio molecules in plants can acts as capping and reducing agents and they have investigated in order to find an eco-friendly technique for production of well characterized effective nanoparticles. The objective of this study aimed to give the scientific evidence of the correlation between antioxidant activity and cytotoxicity in 11 different Egyptian plants and study the effect of nanotechnology technique on the biological activity of the most promising plants which have the ability to synthesis of silver nanoparticles. Phytochemical screening of 70% ethanolic extracts (EEs) has shown to be rich in steroids, terpenoids, flavonoids, tannins and phenols. The antioxidant activity of EEs gave inhibitory concentration of IC50 ranged between 42.33 (Ipomoea batatas leaves) and 1,519.76 og/ml (Citrullus colocynthis fruits) by DPPH method. The antioxidant activity of EEs gave inhibitory concentration of IC50 ranged between 31.60 (Avicennia marina leaves) and 1,133.79 og/ml (Cichorium endivia L. leaves) by ABTS method. The total phenolic content of EEs were ranged between 8.72 ± 0.08 (Daucus carota L. seeds) and 91.67 ± 0.13 (Avicennia marina leaves) as mg GAE/g 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 no correlation with antimicrobial activity. These results proved that the total phenolic content could be indicator to the antioxidant scavenging activity but not the cytotoxic effect

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