Extract of grains of paradise and its active principle 6-paradol trigger thermogenesis of brown adipose tissue in rats.

Grains of paradise (GP) is a species of the ginger family, Zingiberaceae, extracts of which have a pungent, peppery taste due to an aromatic ketone, 6-paradol. The aim of this study was to explore the thermogenic effects of GP extracts and of 6-paradol. Efferent discharges from sympathetic nerves entering the interscapular brown adipose tissue were recorded. Intragastric injection of a GP extract or 6-paradol enhanced the efferent discharges of the sympathetic nerves in a dose-dependent manner. The enhanced nerve discharges were sustained for as long as 3h. The rats did not become desensitized to the stimulatory effects these compounds on sympathetic nerve activity. The tissue temperature of brown adipose tissue showed significant increase in rats injected with 6-paradol. These results demonstrate that GP extracts and 6-paradol activate thermogenesis in brown adipose tissue, and may open up new avenues for the regulation of weight loss and weight maintenance.