Effects of Crude Polysaccharides from Lentinula edodes Obtained by Ultrasound-Assisted Water Extraction on Metabolic and Hepatic Parameters in Obese Rats

A high-fat diet is associated with metabolic disorder, including obesity, insulin resistance, dyslipidemia, and hypertension. Polysaccharides derived from mushrooms have attracted interest for their potential metabolic and anti-inflammatory effects. Nevertheless, the impact of crude polysaccharides derived from the Lentinula edodes (Berk.) Pegler (PSC) on metabolic conditions linked to high-fat diets remains insufficiently studied. This study aimed to evaluate the bioactivity of PSC obtained using ultrasound-water extraction (UW) on metabolic parameters, hepatic function, and inflammation in rats fed a high-fat diet (HFD). Male Wistar rats (5 weeks old, 180–200 g; n = 6 per group) were assigned to normal-diet (ND) or high-fat-diet (HFD) groups, with or without PSC administration. PSC was administered by oral gavage at 400 mg/kg body weight/day for 4 weeks. Compared with the HFD group at week 20, the HFD+PSC group showed 30.44% lower body-weight gain, while LDL-C, AST, ALT, and IL-6 levels were 42.31%, 35.77%, 55.15%, and 41.78% lower. Histopathological examination showed reduced hepatic steatosis and inflammatory alterations following PSC extract administration, with the NAS decreasing from 5.60 ± 0.51 in the HFD group to 2.00 ± 0.32 in the PSC extract administration. The findings indicate that a PSC extract decreased various metabolic, hepatic, and inflammatory changes correlated with HFD. This study supports the potential of PSC extract as a mushrooms-derived functional ingredient to improve metabolic function.