Abstract

IN-VITRO ASSESSMENT OF XANTHINE OXIDASE, SKIN ENZYMES INHIBITORY ACTIVITIES, ANTIRADICAL POTENTIAL AND ULTRAVIOLET SPECTRAL CHARACTERISTICS OF THE METHANOL EXTRACT OF ADENOSTEMMA PEROTTETTII AND ITS COLUMN CHROMATOGRAPHIC FRACTIONS

Olugbenga Kayode Popoola* and Azeez Kola Otunola

ABSTRACT

This study evaluates the antioxidant capacities (AOX) such as: Ferric Reducing Antioxidant Power (FRAP), Trolox Equivalent Antioxidant Capacity (TEAC), Oxygen Radical Absorbance Capacity (ORAC), lipid peroxidation (LPO) inhibition, and oxidative stress related degenerating enzymes (ENZ): xanthine oxidase (XO), tyrosinase (TYR), and elastase (ELA) inhibitory activities using diverse battery of in vitro assays on methanol soluble fractions of Adenostemma perottettii (AP) extract and its chromatographic fractions. The results indicate AP and some column fractions exhibited notable antioxidant activities as: FRAP (IV = 620.99±5.45; V =642.46±6.88; VI = 722.86±2.69; AP = 779.94±3.38 µM AAE/g); TEAC (IV = 1,000.4 ± 0.45; V = 1,149.2±5.21; VI = 2,088.6±0.30; AP = 2,435.3±1.42 µM TE/g); ORAC (VI = 1,431.7± 2.24; AP = 2,175.03± 1.28 µM TE/g), and LPO (AP IC50 = 92.88 µg). Notable enzymes inhibitory activities demonstrated by the tested samples are expressed as IC50 as: TYR (V
=162.5; VI = 125.0; AP = 96.88 µg); ELA (VI = 263.28; AP = 183.59 µg); XO (VI = 197.66; AP = 115.63 µg). The findings suggest that AP extract and some of its fractions contain essential bioactive compounds with promising AOX properties & ENZ inhibitory properties. These results underscore the potential of AP as a source of natural antioxidants and inhibitors for the development of therapeutics targeting oxidative stress-related disorders. Further research is warranted to identify and characterize the active compounds responsible for these beneficial effects.

Keywords: Adenostemma perottettii; Antioxidant; Xanthine Oxidase; Oxidative Stress; Skin Enzymes; Chromatography.