Evaluation of phytochemical, antioxidant and antibacterial activity of Parkia biglobosa STEM bark extract

Abstract

The powdered bark of Parkia biglobosa (Jacq.) Br. ex G. Don., is used by the indigenous traditional medicine men of Yobe State to treat bleeding from cuts and wounds, burns, ulcers, and also in the treatment of abnormal menstrual bleeding. Three crude extracts were prepared from the stem bark of Parkia biglobosa by successive cold extraction with n-Hexane, ethyl acetate and methanol respectively. The dried extracts were subjected to phytochemical screening and antibacterial/antioxidant studies. Phytochemical screening revealed the presence of Alkaloids, carbohydrates, flavonoids, tannins, terpenoids, glycosides, saponins, sterols, and phenols in all the extracts, but saponins and phenols were only present in the methanolic extracts. Oxalates and quinones were not detected in all the three samples. The antioxidant studies (using DPPH Radical Scavenging Activity) revealed that all the three extracts exhibited tremendously higher antioxidant activities than the standard ascorbic acid. Among them the ethyl acetate extract showed the highest activity (-226.16µg/ml) followed by n-hexane (-21.6µg/ml) and methanol (and -2.11µg/ml). Results from the antibacterial studies of the crude extracts showed significant inhibitory activity against the tested pathogenic organisms with zones of inhibition ranging between 27.5-57.5 mm (E. coli), 30-62.5 mm (B. subtilis) 22.5-50mm (S. aureus) and 25-60mm (S. typhi.) as compared to 21-45mm for the control (Ciprofloxacin). These results were taken to indicate that Parkia biglobosa is a promising herbal remedy that contains phytochemicals with strong antioxidant and antibacterial properties. This study further validates and strengthens its continuous use in traditional medicine as remedy for cut/wound healing arising from many sources.