Antimicrobial activity, cytotoxicity, and phytochemical screening of Voacanga globosa (Blanco) Merr. leaf extract (Apocynaceae)

ObjectiveTo determine the antibacterial, antifungal, antiprotozoal, cytotoxic, and phytochemical properties of ethanol extracts of leaves of Voacanga globosa (Blanco) Merr. (V. globosa).MethodsThe extracts were tested against bacteria and fungus through disc diffusion assay; against protozoa through growth curve determination, antiprotozoal and cytotoxicity assays.ResultsThe extract revealed antibacterial activities, inhibiting the growth of Staphylococcus aureus, Bacillus cereus, Pseudomonas aeruginosa, Micrococcus luteus, and Salmonella typhimurium. Antifungal assay showed that it inhibited Candida albicans. The antiprotozoal assay against Trichomonas vaginalis and Entamoeba histolytica showed that V. globosa can inhibit the parasites, wherein the action can be comparable to metronidazole. With the in situ cell death detection kit, Trichomonas vaginalis and Entamoeba histolytica exposed to V. globosa leaf extract was observed to fluoresce simultaneously in red and yellow signals signifying apoptotic-like changes. Preliminary phytochemical screening revealed the chemical composition of plant extract containing alkaloids, saponins, 2-deoxysugars, and hydrolysable tannins.ConclusionsThus, this study provides scientific evidence on the traditional use of V. globosa leaf extract in treating microbial diseases. Further, the leaf extract can possibly be used to produce alternative forms of antimicrobials.