Phytochemical, antimicrobial and acute toxicity studies of <i>Ipomoea asarifolia</i> leaves (Convolvulaceae)

Abstract

Plants have provided sources for novel drug compounds, as plant derived medicines have made large contributions to human health and well-being. The leaves of Ipomoea asarifolia were ground in to powder followed by successive extraction (methanol and water) and then screened for phytochemicals using the standard methods. Antimicrobial activities of the crude extract against clinical isolates were investigated using agar well diffusion, broth dilution methods. The antibiotic susceptibility profiles of the microbial isolates to standard antifungals and antibacterial such as fluconazole and ciprofloxacin respectively were determined using standard methods. Phytochemical screening revealed the presence of tannins, saponins, flavonoids, triterpenes, phenols and alkaloids. The methanol extract of the plant leaves produced the moderate antifungal and antibacterial activity when compared with the standard drug. The antimicrobial sensitivity results revealed that methanolic extract had promising antibacterial and fungal activity at highest concentration 500 mg/ml. Shigella sp. was found to be the most susceptible clinical isolate at 500mg/ml with inhibition zones of 16 mm, Candida kfyer was next most susceptible isolate to methanol extract of the leaves with inhibition zone of 15 mm. Klebsiella sp., Escherichia coli and Shigella sp. showed MIC and MBC of 31.25 mg/ml and 62.5 respectively. The LD50 of Ipomoea asarifolia was found to be greater than 5000 mg /kg and could be considered safe for consumption. Further investigations should be carried out to isolate pure compounds and determine the mechanisms of action of the plant.