Phytochemical, analgesic, antioxidant and antimicrobial activities of <i>Calotropis procera</i> (apple of Sodom) leaves

With the emergence of new drug resistant microorganisms and current anti-oxidative drugs, many medicinal plants will continue to be the best source of drugs which could be administered as herbal supplements. The present study was designed to evaluate the phytochemical content, antimicrobial and analgesic activities of Calotropis procera leaf (methanol extract). Antimicrobial activities was carried out against selected clinical isolates by agar well diffusion method. The anti-oxidative activities of the extracts were determined by means of 2, 2-diphenyl-1-picrylhydrazyl (DPPH) assay. Phytochemical screening revealed the presence of alkaloids, flavonoids, saponins, tannins, phenol, carbohydrate, steroids and triterpenes. Staphylococcus aureus was found to be the most susceptible bacteria at 500 mg/ml with inhibition zone of 17 mm followed by Escherichia coli, Streptococcus pyogenes, and Aspergillus niger, Staphylococcus aureus with 14 mm and MIC of 31.25 mg/ml each. The extract demonstrated dose-dependent varying degrees of anti-oxidative efficacy in the 2, 2-diphenyl-1-picrylhydrazyl radical scavenging assays. For the DPPH assay, IC50 values of 115.2 μg/mL. The analgesic effects observed at 20 mg/kg more than that of 40 mg/kg and 80 mg/kg of the extract. The results showed that Calotropis procera leaf extract possess compounds with antimicrobial, antioxidant as well as analgesic properties. The findings will add value to the traditional uses of Calotropis procera leaves and conservation is necessary due to the significant medicinal properties demonstrated by the plant. Further research on isolation and characterization of the active compounds from fractions that showed antimicrobial and analgesic activities is recommended.