Phytochemical trials and evaluation of the antioxidant activity of plants used in the treatment of type 2 diabetes in the Central African Republic- Case of Khaya anthotheca, Desmodium tortuosum and Millettia laurentii

Abstract

Excess free radicals equivalent to oxidative stress is an important cause of many diseases that pose a serious public health problem. Type 2 diabetes is one of these diseases. In the Central African Republic, it is estimated that more than 60,000 diabetics and 75% of diabetic deaths are caused by cardiovascular complications [1]. The traditional African pharmacopoeia offers an alternative to synthetic antidiabetics. The objective of this study is the phytochemical sorting and evaluation of the antioxidant activity of three samples of plants of the Central African pharmacopoeia known for their antidiabetic activity. The extracts of the three plants are obtained after maceration in ethanol or methanol for 48 hours at room temperature (25 °C.) followed by double filtration on cotton, then on 3 mm wattman paper and evaporation of the filtrates at rotary evaporator. The powder thus obtained allowed us to carry out phytochemical and antioxidant tests. After the phytochemical sorting, the antiradical activity by the DPPH and the inhibition of the lipid peroxidation by the ferric thiocyanate method were evaluated Phytochemical sorting revealed that these plants contain sterols, polyterpenes, polyphenols, flavonoids and saponins. Those exhibiting the antioxidant and antiradical important activity are Khaya anthotheca and Desmodium tortuosum with respectively 10.4 ± 0.3; 9.5 ± 0.7, rich in polyphenols and flavonoids, whereas for Millettia laurentii 13.6 ± 0.5 contains more sterols and polyterpenes with ethanol as solvent but thin-layer chromatography for methanol extracts indicates that the latter also contains a fairly high content of polyphenols.