Abstract
OBJECTIVES: Retinaldehyde inhibits adipogenesis, increases metabolic rate, reduces weight gain, and improves tolerance to a glucose load. We assessed the effects of citral - an inhibitor of retinaldehyde dehydrogenase (the primary enzyme metabolizing retinaldehyde), on body weight, glucose tolerance, fasting plasma glucose and insulin levels, metabolic rate, adipocyte size, and morphology in a diet-induced model of obesity. MATERIALS AND METHODS: Out of the 5 groups of 6-week-old male Sprague-Dawley rats, 4 were maintained on an energy-intense, palatable, diet for a period of - 42 days, while 1 served as the control. After obesity had been induced, 3 groups were treated with daily doses of citral (10, 15, and 20 mg/kg body weight) for a period of 28 days. They were then subjected to metabolic experiments. Body weight, fasting plasma glucose, glucose tolerance to an intraperitoneal glucose load, metabolic rate, and adipocyte size were assessed. RESULTS: Citral-treated groups showed a dose-dependent reduction in body weight gain. They significantly had lower fasting glucose levels, improved glucose tolerance, lower fasting plasma glucose, higher metabolic rate, and smaller adipocytes after drug administration. CONCLUSION: The findings suggest that citral increased energy dissipation (and also reduced lipid accumulation) consequently preventing and ameliorating diet-induced obesity. In addition it improved insulin sensitivity and glucose tolerance. In the current scenario of increasing prevalence of obesity and diabetes, citral may prove as novel agent in its management.