Powder bergamot juice attenuates skeletal muscle complications in an experimental model of metabolic syndrome.

BACKGROUND

Metabolic syndrome (MetS) promotes skeletal muscle complications, which can impair glucose uptake and contribute to the development of diabetes. In contrast, powder bergamot juice (PBJ) possesses bioactive compounds with potential therapeutic applications.

OBJECTIVE

To evaluate the effects of PBJ on skeletal muscle complications in an experimental model of metabolic syndrome.

METHODS

Male Wistar rats were fed a control diet (n = 20) or a high-sugar fat diet (n = 20) with 25% sucrose in drinking water (w/v) for 20 weeks to induce MetS. After this period, animals were then redistributed into two groups (n = 7 each): MetS and MetS + PBJ. PBJ was administered by gavage at 250 mg/kg daily for 10 weeks. Systemic metabolic parameters were measured, and lipid content, fatty acid profile, inflammatory and oxidative stress biomarkers, insulin signaling proteins, and histological outcomes were evaluated in the quadriceps.

RESULTS

PBJ treatment significantly attenuated systemic adiposity and dyslipidemia. In the quadriceps, PBJ markedly reduced triglyceride accumulation and modulated the fatty acid composition, lowering saturated fatty acid (SFA) levels and increasing the desaturation index. Oxidative stress markers, including malondialdehyde, advanced oxidation protein products, and protein carbonylation, were reduced, while antioxidant defenses were enhanced by upregulating nuclear factor erythroid 2-related factor 2 (NRF-2) signaling. Pro-inflammatory cytokines, tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6), were significantly decreased and interstitial collagen deposition was also attenuated. Crucially, PBJ modulated the endocrine response and increased total protein expression of glucose transporter type 4 (GLUT-4) without altering IRS-1 phosphorylation.

CONCLUSION

PBJ attenuated skeletal muscle complications resulting from MetS. However, due to the absence of a healthy control group, these findings demonstrate an improvement relative to the diseased condition, but cannot confirm a return to a normal physiological baseline.