Summary: Research in mice suggests that quercetin inhibits kidney fibrosis and may be a therapeutic candidate for patients with chronic kidney diseases.
Kidney fibrosis occurs in virtually every type of chronic kidney disease. It is the consequence of an excessive accumulation of extracellular matrix (ECM). The ECM is a collection of extracellular molecules secreted by cells that provides structural and biochemical support to the surrounding cells for example collagen. In a simplistic view, kidney fibrosis is a failed wound-healing process of the kidney tissue after chronic, sustained injury/disease. It is a progressive process that ultimately leads to kidney failure and requires dialysis or kidney transplantation.
Previous studies reported that quercetin may inhibit fibroblast activation and ameliorate organ fibrosis in liver, lung and ski. In this study the reseachers investigated the anti-fibrotic role of quercetin in kidneys that have a condition called obstructive nephropathy. They created a kidney fibrosis mouse model where quercetin was injected at 25 mg/kg/day. Analyses showed that renal fibrotic lesions were significantly ameliorated and matrix production was decreased in the quercetin-treated group at day 14 compared to the control group. Also the total collagen content in the kidneys was quantified. Compared to the control group in the mice that received quercetin the collagen deposition was significantly suppressed. Analyses also showed that Quercetin diminishes macrophage accumulation and inflammatory cytokines expression.
To verify toxity the researchers detected the body weight, serum albumin, ALT, AST, total bilirubin (TB) and direct bilirubin (DB) in both groups. There was no obvious difference in those parameters, suggesting that quercetin treatment for 2 weeks didn’t induce obvious toxicity in the mice.
The mechanism via which quercetin acted appeared to be by inhibiting mTOR and β-catenin signaling pathways but doing it independent of Smad3 and Smad1/5/9 phosphorylation in kidney fibroblasts.
Altogether the study demonstrated that quercetin may have potential as a novel therapeutic strategy for treatment of kidney fibrosis.