Title: Cytotoxicity and antioxidant activities of leaf extracts of Varthemia sericea (Batt. et Trab.) Diels
Abstract: Varthemia sericea, is a plant which belongs to the Asteraceae family, and grows wild in the Central Algerian Sahara. According to the traditional medicine pharmacopeia it is used to treat several diseases. This study aimed to assess the phytochemical profile of leaf extracts of Varthemia sericea and investigate in vitro cytotoxicity and antioxidant activities. Total phenolic and flavonoids were analyzed through using colorimetric methods. The antioxidant activity was evaluated by using different complementary tests: Free-radical scavenging, β-carotene bleaching inhibition, reducing power and copper chelation ability. The cytotoxicity was determined by the MTT colorimetric assay. The highest total phenolic content recorded with methanol extract with a value of 283.61 ± 0.58 µg GAE/mg. The ethyl acetate and aqueous residue extracts contained the highest flavonoids contents with values of 54.48 ± 1.29 µg QE/mg and 44.56 ± 0.14 µg QE/mg, respectively. Interesting antioxidant activity was exhibited by the different extracts especially the ethyl acetate and aqueous residue, ethanol and methanol extracts. Furthermore, the petroleum ether, ethyl acetate and aqueous residue extracts showed a significant cytotoxicity activity against MCF-7, HeLa and HL60 cells with IC50 values ranging from 16.15±0.79 to 211.96±3.38 µg/ml, after 72 h of treatment. There is a significant correlation to high level amounts of flavonoids in these extracts which can be attributed to their cytotoxic effects. The extracts from leaves of V. sericea showed promising antioxidant and cytotoxic effects. It suggests that it could be further explored as a potential natural source for the development of a new cancer drug.