Anti-inflammatory and antioxidant effects of anthocyanins in Nonalcoholic fatty liver disease (NAFLD): a systematic review of in vivo studies

Anthocyanins are natural flavonoids, which belong to a group of polyphenols with antioxidant, anti-inflammatory, hypolipidemic and hepatoprotective activities. The aim of this systematic review is to answer the questions "What are the impacts of anthocyanins on inflammatory and oxidative mediators of NAFLD in vivo?" and "What are the possible molecular mechanisms involved in the effects of anthocyanins on NAFLD and hepatic steatosis?" The search was performed at PubMed, Scopus, Web of Science, and Embase databases, and the risk of bias was assessed by the SYRCLE tool. The data analysis was conducted following the PRISMA guidelines. Twenty-three studies performed in animal models evaluating the effects of anthocyanins in inflammatory and oxidative stress mediators in NAFLD were included and evaluated. The anthocyanins demonstrated potential positive effects on inflammation and oxidative stress (OS), in addition to reduced hepatic steatosis. The main results identified were a reduction in TLR, NF-κB, MCP-1/CCL-2, TNF-α, IL-6, and IL-1β in addition to an improvement in antioxidant defense with an increase in Nrf2, SOD, GSH, GPx and CAT and a reduction in OS. The findings from this review provide insights for the development of future studies with anthocyanins on liver health and inflammatory and oxidative parameters. PROSPERO (CRD42024502710).