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-HT1A 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-HT2 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 4h 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-HT2 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.