Chronic (-)-Hydroxycitrate Administration Spares Carbohydrate Utilization and Promotes Lipid Oxidation during Exercise in Mice

Abstract

(-)-Hydroxycitrate (HCA) is an active ingredient that is extracted from the rind of the Indian fruit, Garcinia cambogia, which is available as an herbal supplement and is used to lose weight. In this study, the acute and chronic 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 water (control) orally. Serum free fatty acid levels were significantly higher 100 min after administration in the HCA group, but the respiratory exchange 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 after administration, and in a separate study, the maximum swimming time until 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 administration. Other mice were administered 10 mg HCA or water orally twice a day for 25 d. On d 26, they were placed into metabolic chambers after administration 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 significantly lower in the HCA group during both resting and exercising conditions. These results suggest that chronic administration of HCA promotes lipid oxidation and spares carbohydrate utilization in mice at rest and during running.

Capsiate, a Nonpungent Capsaicin Analog, Increases Endurance Swimming Capacity of Mice by Stimulation of Vanilloid Receptors

“…Details of these equations have been described elsewhere. 10) The data for each chamber were collected every 7 min.…”

“…This same apparatus has been used to evaluate the effects of food and nutrients such as capsaicin, 1) overdose of caffeine 11) and hydroxycitrate. 10) The running system was a treadmill (Simplex II; Columbus, OH, USA) for mice. The system consisted of three running lanes of equal dimensions (28:8 Â 4:7 Â 4 cm); each lane was encased in a metabolic chamber with an internal volume of about 1000 cm 3 .…”

The Anti-fatigue Effects of the Low-Molecular-Weight Fraction of Bonito Extract in Mice

“…The gas analyzer used for the assessment of metabolic rate consisted of twelve acrylic metabolic chambers, an O 2 /CO 2 , analyzer (model RL-600, AlcoSystem Inc., Chiba, Japan), and a switching system (model ANI6-A-S, AlcoSystem Inc., Chiba, Japan) to collect gas from each metabolic chamber. This method was previously used to evaluate the change in metabolic rate after the administration of various compounds 22,23) and to monitor metabolic changes in knockout mice under several conditions. 24) The details of this apparatus were described previously.…”

“…24) The details of this apparatus were described previously. 22,23) Briefly, room air was pumped through the chambers, and expired air from each chamber was dried in a thin cotton column and then directed to an O 2 /CO 2 analyzer. The O 2 and CO 2 concentrations were measured and used for the calculation of oxygen consumption and the respiratory exchange.…”

“…The gas analyzer used for the assessment of metabolic rate consisted of twelve acrylic metabolic chambers, an O 2 /CO 2 , analyzer (model RL-600, AlcoSystem Inc., Chiba, Japan), and a switching system (model ANI6-A-S, AlcoSystem Inc., Chiba, Japan) to collect gas from each metabolic chamber. This method was previously used to evaluate the change in metabolic rate after the administration of various compounds 22,23) and to monitor metabolic changes in knockout mice under several conditions.24) The details of this apparatus were described previously.22,23) Briefly, room air was pumped through the chambers, and expired air from each chamber was dried in a thin cotton column and then directed to an O 2 /CO 2 analyzer. The O 2 and CO 2 concentrations were measured and used for the calculation of oxygen consumption and the respiratory exchange.…”