Phytochemical Screening, Nutrient Analysis and Antimicrobial Activity of the Leaves of Lasianthera africana and Dennettia tripetala on Clinical Isolates

Abstract

The spate of resistance to conventional antibiotics is becoming worrisome. As alternatives, plants are investigated for bioactive components with antimicrobial activity. The aim of this study was therefore to investigate the nutrients and anti-nutrients composition, phytochemical components and antimicrobial activity of Dennettia tripetala and Lasianthera africana extracts on clinical isolates. The leaves were screened qualitatively and quantitatively for phytochemicals using aqueous and ethanolic extracts while the antimicrobial activity was done using standard microbiological techniques. The results of the phytochemical screening showed the presence of alkaloids, glycosides, reducing compounds and polyphenol in both plants. Quantification of the phytochemicals showed that polyphenol was the most abundant with values of 17.63% and 14.66% respectively, in D. tripetala and L. africana. Proximate composition in mg/100 g showed that protein was (19.86 - 5.70), fibre (10.80 -13.86), ash (3.16 - 9.28), carbohydrate (49.70 - 73.04) and fat (7.30 each) in both plants, respectively. The anti-nutrients composition in mg/100 g showed the presence of hydrocyanic acid (6.17 - 7.56), soluble oxalate (7.30 - 17.62), total oxalate (17.10-39.70) and phytate (10.19 - 13.20) in both plants. The antimicrobial activity showed that the aqueous and ethanolic extracts of both plants inhibited the growth of Staphylococcus sp, Esherichia coli, Salmonella sp, Shigella sp, Bacillus sp, and Pseudomonas aeruginosa. The highest inhibition (25 mm) was obtained with the ethanolic extract of L. africana on P. aeruginosa. The minimum inhibitory concentration (MIC) of the extracts ranged from 10 mg to 50 mg with        E. coli and Shigella sp being the most inhibited. The findings of the study reveal that the plants are rich in nutrients, phytochemicals and have antimicrobial activity against isolates. Given the results in this study, there is a need to further exploit the antimicrobial potentials of these plants.