Preliminary Phytochemical Screening and In vitro Antioxidant Prop-erties of Trichilia monadelpha (Thonn.) J. J. de Wilde (Meliaceae)

Abstract

The study evaluated the antioxidant potential and phytochemical constituents in the stem bark extracts of Trichilia monadelpha (Thonn) JJ De Wilde (Family: Meliaceae). Petroleum ether (PEE), ethyl acetate (EthE) and ethanol extracts (EAE) of the stem bark of T. monadelpha were screened for the presence of phytochemicals. The in vitro antioxidant potential of the extracts were also determined using the reducing power and 2, 2-diphenyl-1-picryl-hydrazyl radical (DPPH) scavenging tests respectively. Total phenol content of the extracts was also estimated. Phytochem-ical analysis revealed the presence of important secondary metabolites. Alkaloids, terpenoids, phy-tosterols, reducing sugars and coumarins were present in PEE. EAE had tannins, alkaloids, terpe-noids, phytosterols, reducing sugars, flavonoids, cardiac glycosides, anthraquinones and saponins whiles EthE contained tannins, alkaloids, reducing sugars, cardiac glycosides, anthraquinones, terpenoids and phytosterols. Total phenol contents were estimated to be 7.51±0.87 mg tannic acid equivalent/g of petroleum ether extract, 34.14±0.78 mg tannic acid equivalent/g of ethyl acetate extract and 119.30±3.20 mg tannic acid equivalent/g of hydroethanol extract. The extracts showed a concentration-dependent reduction of Fe³⁺ to Fe²⁺ in the reducing power test as well as concen-tration-dependent DPPH radical scavenging. Of the three extracts, EAE had the most antioxidant activity. Findings of this study suggests that the stem bark of Trichilia monadelpha may be a good source of natural antioxidants and might be useful in treating the diseases associated with oxida-tive stress.

Keywords: Phytochemicals, total phenol content, reducing power, DPPH, antioxidant, free radicals.