Phloroglucinaldehyde Alleviates High-Fat-Diet-Induced MAFLD via Its Antioxidant and Anti-Inflammatory Properties

Metabolic associated fatty liver disease (MAFLD), redefined from non-alcoholic fatty liver disease (NAFLD), is a global health concern driving the search for dietary interventions based on natural compounds. Phloroglucinaldehyde (PGA), a primary phenolic metabolite of the widely consumed anthocyanin cyanidin-3-glucoside (C3G) found in berries and other fruits, has emerged as a promising candidate due to its potential higher bioavailability than its parent compound. This study investigates the protective effects of PGA against high-fat diet (HFD)-induced MAFLD. Using both in vitro (LO2 cells) and in vivo (C57BL/6J mice) models, we found that PGA administration significantly attenuated body weight gain and hepatic steatosis, while reducing serum levels of TG, TC, liver transaminases (AST & ALT), and insulin resistance (p < 0.05). Further liver lipidomic profiling revealed that PGA supplementation specifically down-regulated 46 lipid species (p < 0.05), predominantly triglycerides characterized by long-chain and very-long-chain saturated fatty acids. Mechanistically, PGA enhanced the hepatic antioxidant capacity by increasing superoxide dismutase (SOD) activity (p < 0.05) and decreasing malondialdehyde (MDA) (p < 0.05) and exerted anti-inflammatory effects by reducing pro-inflammatory cytokines (IL-6, TNF, MCP-1) (p < 0.05) and endotoxin levels (p < 0.05). Correlation analyses further linked the down-regulated lipids to improvements in oxidative stress and inflammation. Our findings underscore that PGA, a key bioactive metabolite derived from dietary anthocyanins, alleviates MAFLD through its potent antioxidant and anti-inflammatory properties, highlighting its potential as a functional food ingredient or nutraceutical for metabolic health.