The increased prevalence of obesity and associated insulin resistance calls for effective therapeutic treatment of metabolic diseases. The current PPARγ-targeting antidiabetic drugs have undesirable side effects. The present study investigated the anti-diabetic and anti-obesity effects of withaferin A (WFA) in diet-induced obese (DIO) C57BL/6J mice and also the anti-adipogenic effect of WFA in differentiating 3T3- F442A cells. DIO mice were treated with WFA (6 mg/kg) or rosiglitazone (10 mg/kg) for 8 weeks. At the end of the treatment period, metabolic profile, liver function and inflammatory parameters were obtained. Expression of selective genes controlling insulin signaling, inflammation, adipogenesis, energy expenditure and PPARγ phosphorylation-regulated genes in epididymal fats were analyzed. Furthermore, the anti-adipogenic effect of WFA was evaluated in 3T3- F442A cell line. WFA treatment prevented weight gain without affecting food or caloric intake in DIO mice. WFA-treated group also exhibited lower epididymal and mesenteric fat pad mass, an improvement in lipid profile and hepatic steatosis and a reduction in serum inflammatory cytokines. Insulin resistance was reduced as shown by an improvement in glucose and insulin tolerance and serum adiponectin. WFA treatment upregulated selective insulin signaling ( insr , irs1 , slc2a4 and pi3k ) and PPARγ phosphorylation-regulated ( car3 , selenbp1 , aplp2 , txnip , and adipoq ) genes, downregulated inflammatory ( tnf-α and il-6 ) genes and altered energy expenditure controlling ( tph2 and adrb3 ) genes. In 3T3- F442A cell line, withaferin A inhibited adipogenesis as indicated by a decrease in lipid accumulation in differentiating adipocytes and protein expression of PPARγ and C/EBPα. The effect of rosiglitazone on physiological and lipid profiles, insulin resistance, some genes expression and differentiating adipocytes were markedly different. Our data suggest that WFA is a promising therapeutic agent for both diabetes and obesity.

Purpose We hypothesized that low estrogen levels aggravate obesity-related complications. Diet-induced obesity can cause distinct pathologies, including impaired glucose tolerance, inflammation, and organ injury that leads to fatty liver and chronic kidney diseases. To test this hypothesis, ovariectomized (OVX) rats were fed a high-fat style diet (HFSD), and we examined structural changes and inflammatory response in the kidney and liver. Methods Sprague-Dawley female rats were ovariectomized or sham-operated and divided into four groups: sham-operated rats fed a normal diet (ND); ovariectomized rats fed a normal diet (OVX-ND); sham-operated rats fed a HFSD; ovariectomized rats fed a high-fat style diet (OVX-HFSD). Mean blood pressure and fasting blood glucose were measured on weeks 0 and 10. The rats were sacrificed 10 weeks after initiation of ND or HFSD, the kidney and liver were harvested for histological, immunohistochemical and immunofluorescence studies. Results HFSD-fed rats presented a significantly greater adiposity index compared to their ND counterparts. Liver index, fasting blood glucose and mean blood pressure was increased in OVX-HFSD rats compared to HFSD rats at study terminal. Histological and morphometric studies showed focal interstitial mononuclear cell infiltration in the kidney of HFSD rats with mesangial expansion being greater in the OVX-HFSD rats. Both HFSD fed groups showed increased expressions of renal inflammatory markers, namely TNF-alpha, IL-6 and MCP-1, and infiltrating M1 macrophages with some influence of ovarian hormonal status. HFSD-feeding also caused hepatocellular steatosis which was aggravated in ovariectomized rats fed the same diet. Furthermore, hepatocellular ballooning was observed only in the OVX-HFSD rats. Similarly, HFSD-fed rats showed increased expressions of the inflammatory markers and M1 macrophage infiltration in the liver; however, only IL-6 expression was magnified in the OVX-HFSD. Conclusion Our data suggest that some of the structural changes and inflammatory response in the kidney and liver of rats fed a HFSD are exacerbated by ovariectomy.

The present study compared high-fat style diet (HFSD)-induced renal nerve-dependent dysregulation of the baroreflex control of renal sympathetic nerve activity (RSNA) in ovary-intact and ovariectomized (OVX) rats. Female rats received a normal diet (ND) or a HFSD for 10 weeks prior to the acute study. The rats were anesthetized; RSNA and heart rate (HR) were measured. Acute bilateral renal denervation was performed, and baroreflex gain curves were constructed from the baroreflex changes in RSNA to vasopressor and vasodepressor drugs. Cardiopulmonary baroreflex control of RSNA was assessed by acute saline volume expansion (VE). Mean blood pressure was elevated in the OVX-HFSD rats compared to the HFSD group reaching significance on week 6 of the experimental study (P < 0.01). Adiposity index and creatinine clearance were significantly greater in all HFSD rats compared to their ND counterparts. Fractional excretion of sodium rose initially in all HFSD rats but was normalized towards the end of the study although absolute sodium excretion remained high. In the acute study, baroreflex gain curve sensitivity (A2) of RSNA was similarly decreased in both the HFSD and OVX-HFSD rats by 88% (P < 0.005) and 94% (P < 0.001) respectively compared to their control counterparts, but was normalized following bilateral renal denervation. VE-reduced RSNA in ND and OVX-ND rats by 55% and 52% (both P < 0.001) respectively, but did not alter RSNA in both HFSD and OVX-HFSD female rats. Following bilateral renal denervation, HFSD and OVX-HFSD rats exhibited 37% (P < 0.01) and 24% (P < 0.01) reduction in RSNA respectively. These findings demonstrate that although obesity-induced impairment of baroreflex control of RSNA occurred similarly in HFSD and OVX-HFSD rats, mean blood pressure was increased only in the ovarian hormones deprived-group suggesting that ovarian hormones could have modulatory role on other mechanisms that regulate blood pressure in female obesity. Impact statement Over activation of renal sensory nerve in obesity blunts the normal regulation of renal sympathetic nerve activity. To date, there is no investigation that has been carried out on baroreflex regulation of renal sympathetic nerve activity in obese ovarian hormones deprived rat model, and the effect of renal denervation on the baroreflex regulation of renal sympathetic nerve activity. Thus, we investigated the role of renal innervation on baroreflex regulation of renal sympathetic nerve activity in obese intact and ovariectomized female rats. Our data demonstrated that in obese states, the impaired baroreflex control is indistinguishable between ovarian hormones deprived and non-deprived states. This study will be of substantial interest to researchers working on the impact of diet-induced hypertension in pre- and postmenopausal women. This study provides insight into health risks amongst obese women regardless of their ovarian hormonal status and may be integrated in preventive health strategies.