Medicinal properties of Bulbine natalensis

Bulbine natalensis Baker is a medicinal plant with succulent, aloe-like leaves from the Asphodelaceae family, commonly used by traditional healers to treat blood clotting-related diseases. This research tested the anti-platelet aggregation effect of B.natalensis extracts on rat platelet aggregation separately induced by thrombin, ADP, collagen, epinephrine, papain, bromelain and trypsin. Fresh plant material was extracted sequentially using hexane, chloroform, ethyl acetate, methanol, and water. The chloroform extract had the highest yield. Phytochemical screening revealed the presence of anthraquinones, cardiac glycosides, saponins, tannins, flavonoids and alkaloids. The hexane extract revealed the highest contents of total phenols, flavonoids and proanthocyanidin. Hexane extract also displayed the highest ABTS scavenging activity. Studies reveal that B.natalensis is a good antioxidant. Anti-platelet aggregation activities on rat platelets were observed. The chloroform extract inhibited ADP-induced clotting by 100%. Two compounds were isolated but they were unstable. Based on the spectra obtained and comparing to existing literature data, they were envisaged to be a knipholone.