Phytochemical Screening, Antioxidant and Antiplasmodial Activities of Entandrophragma utile from the Central African Republic

An ethnobotanical survey was conducted in Mbaïki, located in the center of the Lobaye prefecture on National Route 6, 107 km from Bangui, specifically 5 km from Ndolobos in the Moboma commune of Kaou. Its main objective was to understand the traditional uses of Entandrophragma utile (E. utile), a tree known as Sipo, belonging to the Meliaceae family and widely distributed in this area. Information gathered during the ethnobotanical survey and from the literature on the plant enabled chemical screening and the evaluation of its antioxidant activity. Extraction was carried out by sequential cold maceration with four solvents of increasing polarity: cyclohexane (CYHA), dichloromethane (DMC), ethyl acetate (EtOAc) and methanol (MeOH). The methanol extract gave the best yield (10.67%), followed by the ethyl acetate extract (1.1%), dichloromethane (0.84%), and cyclohexane (0.70%). Chemical screening carried out by tube reactions and thin layer chromatography confirmed the presence of: alkaloids (very little present), anthocyanins, catechins, sterols, anthraquinones and triterpenes, flavonoids, very abundant saponosides, narcotics specifically (Tetrahydrocannabinols) and very little coumarins. Chemical family analysis using a 96-well plate reader revealed high polyphenol content in all families compared to others. The polyphenol content of the EtAOc extract was high, at 496.3 ± 18.2 mg eq/g. The EtAOc extract inhibited DPPH more effectively than the others, with an inhibition percentage of 96.00 ± 0.89%. This same extract yielded a resistance index (RI = 0.35) less than one, confirming predominant antiplasmodial activity against the resistant strain. Extracts from the trunk bark of E. utile contained high levels of polyphenols and possessed antioxidant and antiplasmodial activities.