Antiplatelet activity of white and pink Nelumbo nucifera Gaertn flowers

Nelumbo nucifera Gaertn (Nelumbonaceae) a plant used in Ayurvedic medicine (common name: lotus), is a perennial, large and rhizomatous aquatic herb most prevalent in South India. Preliminary phytochemical screening of both white and pink Nelumbo nucifera flowers revealed the presence of phytochemical constituents (flavonoids, alkaloids, phenols etc,). Hence, an attempt has been made to screen the effect of Nelumbo Into} era flowers (both types) on platelet aggregation. The antiplatelet activity of hydroethanolic extract of both types of flowers was studied using platelet-rich plasma in different concentrations (100-500 mu g/ml). Both white and pink Nelumbo nucifera flower extracts showed dose-dependent effective antiplatelet activity with maximum activity at 500 mu g/ml concentration; prevention of platelet aggregation was 50% of that achieved with standard aspirin. Furthermore, the antiplatelet activity of white flowers was relatively high (p<0.05; ANOVA) compared to pink flowers. In conclusion, these observations suggest that both varieties of Nelumbo nucifera flower extracts exert different levels of inhibitory action on platelets in vitro (secretion and platelet aggregation suppression) due to differences in phytochemical content (alkaloids, flavonoids, phenols, tannins, phytosteroids, glycosides and saponins).