Investigations on possible serotonergic involvement in effects of OB-200G (polyherbal preparation) on food intake in female mice

Summary

Background OB-200G is a polyherbal preparation containing aqueous extracts of Garcinia cambogia, Gymnema sylvestre, Zingiber officinale, Piper longum and resin from Commiphora mukul, all possessing thermogenic properties. Our previous studies reveal OB-200G to exert antiobesity effects in dietary animal models of obesity. Aim of the study The present study investigated the possible involvement of serotonergic system in the effect of OB-200G on food intake. We examined the effects of systemic pretreatment with 5-HT depletor, p-chlorophenylalanine (PCPA, 300 mg/kg, i. p. for 6 days), 5-HAT_1A agonist, (8-hydroxy-2-(di-N-propylamino)-tetralin (8-OH-DPAT, 0.1 mg/kg, i. p.), nonselective 5-HT antagonist, cyproheptadine (1 mg/kg, i. p.), 5-HAT² receptor antagonist, seganserin (1 and 2 mg/kg, i. p.) and 2-deoxy-D-glucose (2-DG, glucose antimetabolite, 500 mg/kg, i. p.) on satiety induced by OB-200G (500 mg/kg, p. o.) in non-deprived female mice. The results were compared with fluoxetine (10 mg/kg, i. p.), a selective serotonin reuptake inhibitor. Methods Fifteen minutes after the last drug administration, groups of mice were presented with sweetened chow and the amount of food consumed was recorded at 0.5, 1, 2, 3 and 4 h time intervals. Results The hyperphagic effect of PCPA, 8-OH-DPAT, cyproheptadine and 2-DG was significantly (p < 0.05) antagonized by both OB-200G and fluoxetine. However, the anorectic effect of fluoxetine was not reversed by centrally acting 5-HAT² antagonist, seganserin but the latter markedly attenuated the satiety action of OB-200G. Conclusion The present observations suggest the role of serotonin in mediation of satiety by OB-200G and hence its antiobesity effect.