Background/Objectives: Metabolic dysfunction-associated steatotic liver disease (MASLD) is associated with cardiometabolic risk. Although studies have shown that estradiol positively contributes to energy metabolism via estrogen receptor alpha (ERα), its role specifically in the liver is not defined. Therefore, this study aimed to evaluate the effects of ERα overexpression, specifically in the liver in mice fed a high-fat diet (HFD). Methods: Male C57BL/6J mice were divided into four groups, vehicle fed with regular chow (RC) (RC-Vehicle); vehicle fed an HFD (HFD-Vehicle); AAV-treated fed with RC (RC-AAV); and AAV-treated fed an HFD (HFD-AAV), for 6 weeks (8–10 mice per group). AAV was administered intravenously to induce ERα overexpression. Results: We demonstrate that overexpression of ERα in RC-fed mice reduces body fat (28%). These mice show increased oxygen consumption in cultured primary hepatocytes, both in basal (19%) and maximal respiration (34%). In HFD-fed mice, we showed a decrease in hepatic TAG content (43%) associated with improved hepatic insulin sensitivity (145%). Conclusions: From this perspective, our results prove that hepatic ERα signaling is responsible for some of the metabolic protective effects of estrogen in mice. Overexpression of ERα improves hepatocyte mitochondrial function, consequently reducing hepatic lipid accumulation and protecting animals from hepatic steatosis and hepatic insulin resistance. Further investigations will be needed to determine the exact molecular mechanism by which ERα improves hepatic metabolic health.

Menopause is characterized by a reduction in sex hormones in women and is associated with metabolic changes, including fatty liver and insulin resistance. Lifestyle changes, including a balanced diet and physical exercise, are necessary to prevent these undesirable changes. Strength training (ST) has been widely used because of the muscle and metabolic benefits it provides. Our study aims to evaluate the effects of ST on hepatic steatosis and insulin resistance in ovariectomized mice fed a high-fat diet (HFD) divided into four groups as follows: simulated sedentary surgery (SHAM-SED), trained simulated surgery (SHAM-EXE), sedentary ovariectomy (OVX-SED), and trained ovariectomy (OVX-EXE). They were fed an HFD for 9 weeks. ST was performed thrice a week. ST efficiently reduced body weight and fat percentage and increased lean mass in OVX mice. Furthermore, ST reduced the accumulation of ectopic hepatic lipids, increased AMPK phosphorylation, and inhibited the de novo lipogenesis pathway. OVX-EXE mice also showed a better glycemic profile, associated with greater insulin sensitivity identified by the euglycemic–hyperinsulinemic clamp, and reduced markers of hepatic oxidative stress compared with sedentary animals. Our data support the idea that ST can be indicated as a non-pharmacological treatment approach to mitigate metabolic changes resulting from menopause.

Metabolic dysfunction-associated steatohepatitis (MASH) is characterized by hepatic steatosis, inflammation, fibrosis, and metabolic dysfunction, with limited therapeutic options currently available. This study investigated whether pharmacological inhibition of Galectin-3 (Gal-3), a β-galactoside-binding lectin implicated in inflammation and fibrosis, using modified citrus pectin (MCP), attenuates established MASH in ApoE-deficient mice. Mice were assigned to four groups: standard chow (CTL), standard chow plus MCP (CTL + MCP), Western diet with fructose-enriched drinking water (WD), and WD plus MCP (WD + MCP). MCP (1% in drinking water) was administered during the final four weeks of the 11-week experimental protocol, after the establishment of metabolic dysfunction and hepatic steatosis. Compared with untreated WD mice, WD + MCP mice exhibited improved glucose tolerance, as evidenced by a 22.9% reduction in glucose area under the curve (p = 0.01), and enhanced hepatic insulin signaling, reflected by a 254.1% increase in insulin-stimulated AKT2 phosphorylation (p = 0.0002). MCP treatment also reduced hepatic lipid accumulation (39.8%, p = 0.0055) and hepatic triglyceride content (26.1%, p = 0.0003), accompanied by reductions in circulating triglyceride and cholesterol concentrations. Furthermore, WD + MCP mice exhibited reduced hepatic Gal-3 expression (25.8%, p = 0.0199), decreased F4/80 immunoreactivity (49.2%, p = 0.0061), attenuated JNK phosphorylation (46.6%, p = 0.0118), reduced collagen deposition (47.0%, p = 0.0002), and lower plasma ALT (52.9%, p = 0.0009) and AST (48.8%, p = 0.04) activities. Collectively, these findings demonstrate that MCP attenuates multiple metabolic, inflammatory, fibrotic, and hepatic injury features of established Western diet-induced MASH, supporting Gal-3 as a promising therapeutic target and MCP as a potential pharmacological strategy for MASH.