Natural products against renal fibrosis: molecular mechanisms, safety concerns, and translational perspectives

Renal fibrosis represents a shared pathological endpoint that drives the progression of chronic kidney disease (CKD) toward end-stage kidney disease (ESKD). Although current therapies can delay CKD progression, they have limited capacity to reverse established fibrotic remodeling, underscoring the need for mechanism-oriented anti-fibrotic interventions. Plant-derived preparations have long attracted attention because of their multi-component, multi-target, and multi-pathway pharmacological profiles. More recently, advances in separation, purification, and pharmacological evaluation have redirected research interest from crude extracts toward defined bioactive natural products. A growing body of evidence suggests that flavonoids, alkaloids, terpenoids, glycosides, polyphenols, quinones, and other natural products may exert anti-fibrotic effects by targeting key pathological processes, including inflammation, oxidative stress, mitochondrial dysfunction, metabolic reprogramming, autophagy dysregulation, epigenetic regulation, and regulated cell death. This review summarizes recent advances in the use of natural products for the treatment of renal fibrosis, with a particular focus on their underlying molecular mechanisms, current status of clinical translation, and the challenges that remain.