Depot-specific effects of coffee parchment polyphenols on subcutaneous and visceral adipose tissue: metabolic and antioxidant insights in obesity

Coffee parchment, an abundant by-product of coffee processing, is rich in bioactive compounds and represents a nutraceutical resource. This study investigates the differential effects of aqueous and hydro-methanolic coffee parchment extracts on visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) metabolism and oxidative status in an obesity rat model. Dried coffee parchment was used to prepare aqueous extracts using distilled water and ultrasonic treatment, and hydro-methanolic extracts using water/methanol mixture. Male Wistar rats were fed a cafeteria diet to induce obesity, and then treated with aqueous or hydro-methanolic extracts (100 mg/kg/day). SAT and VAT depots were analyzed for lipids, lipogenic/lipolytic enzymes, and redox markers. Coffee parchment supplementation reduced VAT mass, increased SAT mass, improved insulin sensitivity, and restored antioxidant capacity in obese rats. In VAT, both extracts decreased lipids, with enzyme modulation. In SAT, extracts promoted lipid storage via increased lipogenic enzymes with reduced lipolysis. The aqueous extract exerted stronger effects on VAT lipid reduction and subcutaneous fat preservation. In conclusion, parchment polyphenols modulate adipose tissue distribution, shifting lipid storage from metabolically harmful VAT to SAT, while improving systemic metabolic and oxidative status. These findings highlight the potential of coffee parchment as a sustainable functional ingredient for obesity management.