Green Tea Compound Shows Potential to Protect Podocytes in FSGS

Focal segmental glomerulosclerosis (FSGS) has an estimated global incidence of about 7 per million and is strongly tied to progression to end-stage kidney disease. It remains a difficult disease to treat. Supportive care and immunosuppression help some patients, but podocytes are terminally differentiated and cannot regenerate, so each one lost is gone for good. A preclinical study published in Renal Failure investigated whether epigallocatechin-3-gallate (EGCG), a bioactive polyphenol with antioxidant and anti-apoptotic properties, could reduce podocyte injury and alleviate FSGS-associated kidney damage. The team worked across three systems: human tissue, an animal model, and cultured cells.

Identifying Molecular Signatures of Podocyte Injury
The investigators combined human kidney tissue analysis with mouse and cell culture experiments to characterize podocyte injury and evaluate EGCG's protective effects. Kidney biopsies from three patients with primary FSGS were compared with non-tumorous kidney tissues from three patients undergoing nephrectomy.

Using single-nucleus RNA sequencing (snRNA-seq), researchers identified distinct populations of healthy and injured podocytes. Similar analyses were performed in mice with adriamycin-induced nephropathy, an experimental model that reproduces features of FSGS. Across both human and mice, snRNAseq identified 360 commonly dysregulated genes, with enrichment in pathways associated with apoptosis and fatty acid metabolism. Additional analyses suggested increased activity of ROS-related and apoptotic pathways in injured podocytes, supporting oxidative stress as a potential therapeutic target.

EGCG Reduces Kidney Injury in Mice
To evaluate EGCG's effects, researchers administered 100 mg/kg/day orally for six weeks to mice with adriamycin-induced nephropathy. Compared with untreated mice, EGCG-treated mice demonstrated significant improvements in several measures of kidney injury:

• Proteinuria: The urinary albumin-to-creatinine ratio decreased significantly (p<0.001), although it remained elevated compared with healthy controls.
• Glomerular scarring: Histological examination showed reduced glomerulosclerosis, accompanied by a significantly lower glomerulosclerosis index (p=007).
• Oxidative stress: EGCG significantly restored the reduced glutathione-to-oxidized glutathione (GSH/GSSG) ratio in serum and kidney tissue, indicating improved antioxidant balance.

These findings suggest that EGCG may alleviate FSGS-associated kidney injury, potentially through its antioxidant effects.

Cellular Experiments Reinforce Protective Effects 
To take a closer look at how EGCG might protect podocytes, the researchers tested its effects in cultured mouse podocytes exposed to Adriamycin. Adriamycin reduced cell viability to approximately 50%, whereas EGCG treatment improved viability to approximately 70% (p=0.002). Flow cytometry further demonstrated reduced intracellular ROS accumulation and fewer apoptotic cells following EGCG treatment, which reinforces the proposed connection between EGCG's antioxidant activity and improved podocyte survival.

Implications for Future FSGS Treatment 
The study provides preliminary evidence that EGCG may protect podocytes by reducing oxidative stress and apoptosis, potentially offering an adjunctive therapeutic strategy for FSGS.

However, the findings remain preclinical. The small human tissue sample, limitations of the adriamycin model, and absence of comparisons with established therapies restrict their clinical applicability. Additionally, the investigators did not fully characterize EGCG's molecular mechanisms or its effects on renal tubular cells.

Further mechanistic investigations and clinical studies are needed to determine whether these protective effects translate into meaningful benefits for patients with FSGS.

Reference:
Wang X, Shen X, Qing J, Lu D. Epigallocatechin-3-gallate attenuates oxidative stress and apoptosis in podocytes of focal segmental glomerulosclerosis. Ren Fail. 2026;48(1):2711462. doi:10.1080/0886022X.2026.2711462