Hepato-Renal Axis: A Systematic Review of Anthocyanin Protective Mechanisms of Preclinical Evidence.

Hepatic and renal dysfunctions are interrelated through oxidative stress and inflammatory cascades, establishing a bidirectional pathogenic loop. Anthocyanins, potent polyphenols, are known for hepato-renal protective effects. This systematic review synthesizes preclinical evidence on the protective mechanisms of anthocyanins in hepatic and renal models and evaluates methodological rigor using validated risk-of-bias tools. A comprehensive search was conducted in Web of Science, Scopus, ScienceDirect, Taylor & Francis Online, Wiley Online Library, PubMed, and Google Scholar, complemented by grey literature and citation searching, covering January 2010 to November 2025 (accessed November 25, 2025). Eligible in vitro and in vivo studies were assessed using the Modified ToxRTool for in vitro and the SYRCLE tool for animal studies. Of the initially identified 667 records, 31 studies met the inclusion criteria: 3 in vitro, 7 using both in vitro and in vivo models, and 21 in vivo. In vitro studies showed low bias except for compound stability confirmation, whereas among in vivo studies, 16 showed high, 9 moderate, and 3 low risk of bias. Anthocyanin administration decreased ALT, AST, BUN, and creatinine, enhanced antioxidant enzymes, and reduced histopathological injury via Nrf2/HO-1 activation and NF-κB suppression.