Phytochemical Analysis and Antibacterial Activity of Ethanolic Leaf Extract of Solanum torvum Sw. Against Pathogenic Bacteria

Abstract

Solanum torvum Sw. is one of the important medicinal plants belonging to the family Solanaceae. Different parts of the plant are reported to possess a number of medicinal properties. This study determined the phytochemical constituents and antibacterial activity of the ethanolic extract of S. torvum leaves using gas chromatography-mass spectrometry and broth microdilution assays, respectively. Phytochemical analysis demonstrated the presence of 32 chemical constituents which were mainly phenolic compounds, terpenoids, palmitic acid, palmitic acid ester, linoleic acid, linolenyl alcohol, linolenic acid ester and stearic acid. The antibacterial activity of the extract was tested against five pathogenic bacteria (Staphylococcus aureus, Staphylococcus intermedius, Staphylococcus epidermidis, Bacillus cereus and Pseudomonas aeruginosa) and exhibited growth inhibition against all tested bacteria with minimum inhibitory concentration and minimum bactericidal concentration values that ranged between 1.95 and 31.25 mg.mL-1. The strongest antibacterial activity of the extract was found against Bacillus cereus. This corresponded to the efficacies of the phenolic compounds and terpenoids detected in the extract. The study suggested that the ethanolic extract of S. torvum leaves is promising for development in the treatment of various infectious diseases in the future.