Evaluation of phytochemicals, antimicrobial activity and antioxidant potential of methanolic extract of Vitellaria paradoxa nut (shea nut)

The side effects of commonly used antimicrobial drugs and frequent development of antimicrobial resistance motivate scientific researchers to search for new antimicrobial agents. This study evaluated the phytochemical constituents, antimicrobial activity and antioxidant potential of Vitellaria paradoxa nut (shea nut) extract. The phytochemical screening was done to know the secondary metabolites present in the shea nut extract. Antimicrobial assays were done on S. aureus ATCC 25923, E. faecalis ATCC 29212, E. coli ATCC 25922, P. aeruginosa ATCC 4853, MRSA, E. coli ESLB (NCTC13351), S. typhi (ATCC334538), S. typhimurium (ATCC13311), N. gonorrhoeae (NCTC12700), K. pneumoniae (ATCC7004603), B. cereus (NCTC10320), and C. albicans (ATCC10031), by employing an agar diffusion method and broth dilution method. Antioxidant activity was carried out by DPPH radical scavenging activity mechanism. The results revealed a diverse array of bioactive compounds, including terpenoids, steroids, alkaloids, tannins, flavonoids, reducing sugars and saponins. The shea nut extract exhibited significant antimicrobial activity against Salmonella typhimurium, Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, and Pseudomonas aeruginosa, with minimum inhibitory concentration (MIC) of 0.78125 mg/mL for these organisms. The highest DPPH radical scavenging potential exhibited by the extract was found to be 93.92±0.21 %. At the lowest concentration of 3.90625 µg/mL the DPPH radical scavenging activity of the extract was 31.12±0.16 % while that of ascorbic acid was 17.71±0.48 %. The methanolic extract of Vitellaria paradoxa nut possessed antimicrobial and antioxidant activities and were found to contain many secondary metabolites which may be responsible for its biological activity.