Antioxidant Activity and Phenolic Composition of Ethanol Extracts of Momordica charantia and Datura stramonium

Abstract

Medicinal plants in the world are natural antioxidant sources as they contain some secondary metabolites such as phenolic acids and flavonoids. Therefore, they are used to prevent or treat many diseases in many parts of the world. However, the use of antioxidants in cancer treatment is still controversial. Accordingly, the phenolic composition and antioxidant potential of the ethanol extracts of Momordica charantia L. (Cucurbitaceae) and Datura stramonium L. (Solanaceae), which are used traditionally in Turkey and have cytotoxic potential on human cancer cells, were investigated. The antioxidant assays (DPPH, metal chelating, phosphomolybdenum, and ferric reducing power) were applied to the ethanol extracts of the fruits of M. charantia and the leaves of D. stramonium. The total phenolic and flavonoid contents were determined. The phenolic compounds contained in ethanolic extracts were identified using HPLC method. Fifteen phenolic compounds were identified in the extracts. Caffeic acid was the major constituent in both extracts. The amount of caffeic acid was detected to be 6282.51 and 15183.36 µg g-1 extract in M. charantia extract and the D. stramonium extracts, respectively. D. stramonium leaf extract showed higher antioxidant activity than M. charantia fruit extract and this activity may be associated with high phenolic compound concentrations. Hence, further studies about screening of bioactive compounds from various part of these plants will be a great importance for obtaining of source of novel natural antioxidants.