Abstract

Olga Nana*, Jean Momeni, Roli KaroleTsatsop, Philemon Zé Bilo’o and Martin Benoit Ngassoum

ABSTRACT

A seek was made in this study to determine the influence of different factors on the extraction process of Trichilia emetica (Vahl) root bark. Conventional solvent extraction (CSE) and microwave assisted extraction (MAE) were practised, then compared. The obtained extracts were used to conduct different antioxidant investigations. A monothetic analysis method was used for the designing experiments. Four independent variables were tested and the maximum extraction efficiency was achieved with irradiation time X1 of 90 s, microwave irradiation power X2 of 700 W, liquid-to-solid ratio X3 of: 20:0.7 (mL/g) and methanol concentration X3 30%. The total flavonoids content of 529.01 μg QE/g DW were obtained under these optimum conditions. The antioxidant investigation of the later MAE extract exhibited the highest values of DPPH radical-scavenging assay with inhibition percentage (IP) of 86 %, an antioxidant activity (AOA) of 90.36 % in the β-carotene bleaching test and the chelating power (CP) of 82.5% compared to CSE. The total flavonoids contents obtained by microwave-assisted extraction were twice those obtained by conventional solvent extraction. Second-order polynomial model could be employed to obtain the maximum total flavonoids. A correlation study of a mathematical regression model and “one-variable-at-a-time” (OVAT) were used for describing the effects of the MAE factors on the extraction. The response surface methodology is conductive to optimize the extraction process. With such good antioxidant potentials of flavonoids from T. emetica root bark, this plant is suitable to solve the antioxidant deficiency manifested over time by the body through degenerative diseases and oxidative stress.