Intragastric administration of cuminaldehyde, a natural TRPA1 agonist, enhanced carbohydrate oxidation and reduced body fat accumulation in mice

Transient receptor potential ankyrin 1 (TRPA1) is a nociceptive receptor activated by chemical compounds such as allyl isothiocyanate, cinnamaldehyde, and carvacrol, found in spices and herbs. Since the intake of some TRPA1 agonists inhibits visceral fat accumulation, TRPA1 agonists are expected to serve as ingredients in anti-obesity foods. Recently, it has been reported that anisaldehyde, tiglic aldehyde, and cuminaldehyde activate TRPA1. In the present study, we measured metabolic changes after a single intragastric administration of each of these three compounds by respiratory gas analysis in mice, revealing cuminaldehyde's outstanding carbohydrate metabolism-enhancing effect. Next, mice were fed a high-fat diet for 4 weeks, during which they received daily administration of either cuminaldehyde or vehicle. The cuminaldehyde-treated group exhibited a significant suppression of visceral fat accumulation. Respiratory gas analysis confirmed that oxygen consumption and fat oxidation in normal conditions were significantly higher in the cuminaldehyde group than in the vehicle group at 2 weeks post-administration. These results suggest that the intake of cuminaldehyde, a TRPA1 agonist, enhances energy metabolism and reduces visceral fat accumulation.