The tannin content and anti platelet-aggregation activity of Cinnamomum sintoc extract

Abstract

Plants of the genus Cinnamomum are known to have anti-thrombotic activity via the inhibition of platelet activation and improvement to blood circulation. Previous studies have indicated that Cinnamomum sintoc (CS) has a potent anti-platelet aggregation activity, which is induced by adenosine diphosphate (ADP). In this study, we report the anti-platelet activity of the CS extract and its correlation with the tannin content. Dried powder of CS bark was macerated using dichloromethane, which was followed by the same procedure using methanol. The filtrate was then evaporated and the dried methanolic-extract was triturated using ethyl acetate, yielding ethyl acetate soluble and insoluble fractions. Both fractions were then evaluated for their tannin content and tested for antiplatelet aggregation activity induced by ADP in a light transmission aggregometer. It was found that the tannin content and the anti-platelet activity had a positive correlation. The dichloromethane, methanol, ethyl acetate-soluble, and ethyl acetate-insoluble fractions inhibited platelet aggregation by 26.9%, 53.6%, 7.2% and 51.4%, respectively. While their tannin content was, not detected (n.d), 24.8, 0.2 and 21.4 mg catechin equivalent (CE) per 100 mg of extract, respectively. Furthermore, it was established that the inhibitory concentration 50% (IC50) for the methanolic extract was 98.62 ppm. These results indicated that tannin may be responsible for the anti-platelet activity of the CS methanolic extract.