Chronic (-)-hydroxycitrate administration spares carbohydrate utilization and promotes lipid oxidation during exercise in mice

(-)-Hydroxycitrate (HCA) is an active ingredient that is extracted from the rind of the Indian fruit, Garcinia cambogia, which is available as an herb al supplement and is used to lose weight. In this study, the acute and chro nic effects of HCA on energy metabolism were examined in male Std ddY mice. Mice were placed into metabolic chambers and administered 10 mg HCA or wat er (control) orally. Serum free fatty acid levels were significantly higher 100 min after administration in the HCA group, but the respiratory exchang e ratio was not different from that in the control group. The concentration of glycogen in the gastrocnemius muscle was higher in the HCA group 16 h a fter administration, and in a separate study, the maximum swimming time unt il fatigue was slightly longer (P = 0.21) than that in the control group on d 1.The difference was significant on d 3 after 3 d of HCA or water admini stration. Other mice were administered 10 mg HCA or water orally twice a da y for 25 d. On d 26, they were placed into metabolic chambers after adminis tration and allowed to rest for 1 h, followed by 1 h of running at 15 m/min . Respiratory gas was monitored. The respiratory exchange ratio was signifi cantly lower in the HCA group during both resting and exercising conditions . These results suggest that chronic administration of HCA promotes lipid o xidation and spares carbohydrate utilization in mice at rest and during run ning.