Evaluation of the Antioxidant Activity of Aqueous and Methanolic Extracts of Tetrapleura tetraptera Leaves (Schum. & Thonn.) Taub. (Fabaceae)

Abstract

The objective of this study was to perform the determination of polyphenol and antioxidant activity evaluation of aqueous and methanolic extracts of Tetrapleura tetraptera (Fabaceae) leaves, a plant that is used in the traditional treatment of diabetes in Western Côte d’Ivoire. The quantitative estimation of total phenol contents by the colorimetric method showed that Methanolic Extract (ME) of leaves at 170 ± 0.88 mg GAE/g of extracts while Aqueous Extract (AqE) contains 140 ± 6.9 mg GAE/g of extracts. For flavonoids, the amount determined for ME is 87.33 ± 0.45 mg EQ/g of extracts, while AqE of leaves gave 54.66 ± 5.9 mg EQ/g. The results obtained indicate that ME of leaves from T. tetraptera contains more polyphenol compounds than AqE of leaves. The evaluation of the antioxidant activity of the various extracts was carried out according to two methods: the trapping of free radicals by the DPPH and the measurement of reducing power (FRAP). The antiradicalar power of ME of leaves gave an CI50 = 03.80 ± 0.97 μg/mL close to vitamin C (CI50 = 01.25 0.02 μg/mL) and higher than that of AqE of leaves with an CI50 = 08.60 ± 0.5 μg/mL. Similarly, for reducing power, ME of leaves with an CI50 = 04.24 ± 0.27 μg/mL, is similarly close to vitamin C (CI50 = 04.08 ± 0.01 μg/mL) and more effective than AqE of leaves (CI50 = 24.80 ± 0.37). So, this antioxidant activity could be an additional asset for the use of this plant in the traditional treatment of diabetes and other pathologies related to oxidative stress.