ScienceAsia 18 (1992): 129-140 |doi: 10.2306/scienceasia1513-1874.1992.18.129
INHIBITORY EFFECT OF CAPSAICIN ON INTESTINAL THIAMINE ABSORPTION IN MICE
CHAIVAT TOSKULKAO,a PANADDAHA HATTHACHOTE,a PORNCHAN SAITONGDEEb AND THIRAYUDH GLINSUKONa
ABSTRACT: The effect of capsaicin, a pungent principle oE Capsicum fruits, on intestinal thiamine absorption was examined in mice. In situ study with 14C-thiamine hydrochloride by using intact jejunal loops, active thiamine absorption was found to reduce after exposed to Capsaicin 742 mg% for 30 minutes. The maximum inhibition was observed approximately 45.82% at a concentration of capsaicin 42 mg%. The percent inhibition of thiamine absorption
was related to capsaicin concentration. In contrast, capsaicin did not affect absorption of
high concentration of thiamine in the intestinal lumen. The possible mechanism of capsaicin inhibitory action on thiamine absorption was also investigated. Capsaicin at concentrations of 3.5, 7, 14 and 21 mg% reduced the activity of Na+-K+ ATPase by 6.97%, 14.26%,
17.21 % and 19.40% respectively while the mucosal ATP content was significandy inhibited by capsaicin only at 42 mg%. Moreover, no inhibitory dfect of Capsaicin on thiamine uptake in the intestinal brush-border membane vesicles was seen. These results suggest that there is a correlation between capsaicin inhibition of mucosal Na+-K+ ATPase activity and mucosal ATP content and the reduction of thiamine absorption in mouse jejunum in situ.
Departments of Physiologya and Anatomy,b Faculty of Science, Mahidol University, Rama 6 Road, Bangkok 10400, Thailand.
Received May 22, 1992