Cardiovascular actions of capsaicinoid extract from Thai capsicum

Abstract

Capsaicinoids are spicy substance found in capsicum fruits, the best known component of capsaicinoids being capsaicin. The objective of this study is to develop the extraction method of capsaicinoids from fruits of Capsicum frutescens L. found in Thailand and to study the cardiovascular actions of the extract on rat aorta, platelet aggregation, skin blood flow as well as skin irritation in comparison with capsaicin. Formulation of a capsaicinoid cream and test for its effect on skin blood flow in healthy volunteers were also performed. It was found that the extraction of capsaicinoids using dichloromethane, followed by column chromatography eluted with dichloromethane and methanol (98:2) yielded 2.6% capsaicinoids. Cardiovascular studies on blood vessels showed that both capsaicinoids and capsaicin could inhibit vasconstriction induced by norepinephrine and the vasocilatation effect of capsaicinoids might be due to the action of capsaicin. Both capsaicinoids and capsaicin caused significant decrease in platelet aggregation induced by ADP and collagen. Comparison of capsaicin with capsaicinoid extract having the same amount of capsaicin revealed that capsaicin had higher anti-platelet aggregating activity than capsaicinoids. This indicated that there might be other substances in the mixture which could decrease the anti-platelet aggregating effect. As for the irritation effects, capsaicinoids and capsaicin caused the same degree of irritation on rabbit skin. Both capsaicinoid and capsaicin significantly increased skin blood flow in healthy volunteers.