Phytochemical evaluation and in vitro antioxidant status of Clerodendrum volubile (an indigenous medicinal plant)

Clerodenrum volubile is an important locally used medicinal plant. It is one of the essential herbs,nature has provided for mankind to be consumed as spices, vegetable and is also used in the treatment of diseases. Qualitative phytoconstituent screening of the plant revealed the presence of steroids, flavonoids, tannins, saponinsand phenolic compound while chalcones, alkaloid and anthraquinone were absent. Quantitative phytochemical evaluation showed values of 8.29±1.26mg/g rutin equivalent for flavonoids, 3.53±0.05mg/g gallic acid equivalent for phenol, 3.97±0.03mg/g tannic acid equivalent for tannins and 13.67±1.27% for saponin per dry weight. As it is imperative to extend research work on therapeutic effects of the arsenal of plants,nature has given to us in Africa,so as to obtain a cure for various diseases attacking human's health, antioxidant properties of the plant was evaluated. Antioxidant models used include iron chelating, DPPH(2,2-diphenyl-1-picrylhydrazyl) radical, superoxide ion, hydrogen peroxide, ABTS (2,2′-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid) radical, hydroxyl radical scavenging activities and ferric ion reducing properties. The obtained IC50(concentration of an inhibitor where the response (or binding) is reduced by half) values against DPPHradical were 141.342 and 120.349µg/mL for Clerodendrum volubile and trolox respectively. The chelating effect of the plant extract at 50% inhibition was close to that of ascorbic acid (standard) with 134.34 and 131.19µg/mL concentration respectively. Overall, the aqueous extract of the plant showed antioxidant potential which was close to the effects exerted by known standard antioxidants (ascorbic acid, trolox and EDTA). The plant could hence provide natural antioxidants which are needed to combat numerous free radical-mediated diseases and complications such asaging, cancer and atherosclerosiswhich are linked with oxidative stress.