Investigation of Phytoconstituents, Antibacterial Activity and Cytotoxic Effect of Ficus exasperata Leaf Extracts

Abstract

Aim: The aim of this study was to subject Ficus exasperata to standard scientific scrutiny by investigating the phytochemical composition as well as the antibacterial activity and cytotoxic effect of its leaf extract. Methodology: The plant leaf was air-dried under shade and thereafter ground mechanically, macerated in a solvent (ethanol) for 48 hr and dried using rotary evaporator. The presence of phytochemicals was assayed qualitatively; agar well diffusion method was used to assess the antibacterial activity while brine shrimp assay was used to determine the cytotoxic potential of the plant extract. Results: The qualitative phytochemical screening of Ficus exasperata leaf extract revealed the presence of alkaloid, tannin, flavonoids and cardiac glycoside whereas saponin and steroids were absent. In the antibacterial activity assay, Klebsiella pneumoniae showed the highest susceptibility against the leaf extracts at all the test concentrations recording inhibition zone range of 7.33±0.58 mm to 18.33±0.58 mm. The least zone of inhibition (11.67±0.58 mm) was recorded against Streptococcus pneumonia at the highest concentration used (50 mg/ml). The lowest minimum inhibitory concentration (2.5 mg/ml) of the extract was found against S. aureus, S. pneumoniae, E. faecalis and K. pneumonia while the highest MIC value (25 mg/ml) was recorded against S. typhi and Ps. aeruginosa. The plant’s leaf extract completely killed three of the pathogens within 10 minutes of exposure these were S. aureus, E. faecalis and K. pneumoniae. Higher mortality percentage of brine shrimp was observed with the increase in concentrations of the extracts with an LC50 value of 39.76 ppm was obtained for the extract. Conclusion: From the foregoing, there is a great amount of evidence suggesting that the ethanol extract of Ficus exasperata leaf contained bio-active substances which confer on it antibacterial activity and cytotoxic effect. Therefore, it may be expediently exploited in the development of new antibiotics especially against susceptible bacteria.