Saponin-rich extract of Tribulus terrestris alleviates systemic inflammation and insulin resistance in dietary obese female rats: Impact on adipokine/hormonal disturbances

Abstract

Tribulus terrestris saponins (TTS) have been longley used as an overall tonic and recent studies showed they influence inflammatory conditions. We examined the ameliorative effect of a commercial formula of a saponin-rich extract of TT in a model of dietary obesity in female rats focusing on their ability to control the inflammatory burden, insulin resistance (IR), adipokine expression and the related reproductive system pathologies. Female rats were fed with high fat diet (HFD) for 14 weeks to launch diet-induced obesity; they were assigned as: the obese control female rats (OFR) which received no treatment and TTS (5 and 10 mg/kg/day) treated rats; they were compared to a normal rat group. We determined the IR index, serum/tissue inflammatory cytokines, and adipose tissue adipokine expression and examined the secondary ovarian pathologies. Body weight gain, serum triglycerides and IR (>5-fold) in the OFR group were greater than the normal group; TTS lessened these parameters compared with the OFR group. TTS, at 10 mg/kg dose, ameliorated mRNA expression of leptin and visfatin genes in addition to serum inflammatory cytokine levels. Moreover, TTS corrected the hyperprolactinemia and other hormonal disturbances and ameliorated the ovarian pathologies. This study highlighted that the anti-inflammatory properties of TTS helped in alleviation of IR and body weight gain in OFR. Upon correction of obesity manifestations, the gonadal hormone dysregulations and ovarian pathologies were subsequently ameliorated. We can consider TTS as a promising candidate that may alleviate the inflammatory burden, IR and adipokine expression in obesity and hence prevent the secondary gonadal complications in female subjects if appropriate clinical studies are available.

Keywords: Adipokine expression; Insulin resistance; Ovarian/uterine pathology; Rat dietary obesity; Reproductive hormone dysregulation; Saponins rich extract of Tribulus terrestris; Systemic inflammation.