Epigallocatechin-3-gallate ameliorates renal endoplasmic reticulum stress-mediated inflammation in type 2 diabetic rats

Epigallocatechin-3-gallate (EGCG), an essential polyphenolic constituent found in tea leaves, possesses various potent biological activities. This research was undertaken to investigate the impact of EGCG against endoplasmic reticulum (ER) stress-mediated inflammation and to clarify the underlying molecular mechanism in type 2 diabetic kidneys. The male rats were randomized into four groups: normal, diabetic, low-dose EGCG, and high-dose EGCG. In type 2 diabetic rats, hyperglycemia and hyperlipidemia noticeably caused renal structural damage and dysfunction and aggravated ER stress. Meanwhile, sustained ER stress activated the NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasome and then upregulated the contents of inflammatory cytokines in the diabetic kidney. Following supplementation with 40 mg/kg and 80 mg/kg EGCG, hyperglycemia, hyperlipidemia, and renal histopathological alterations and dysfunction were noticeably ameliorated; renal ER stress, NLRP3 inflammasome, and inflammatory response were markedly repressed in the EGCG treatment groups. In summary, the current study highlighted the renoprotective effects of EGCG in type 2 diabetes and its mechanisms are mainly associated with the repression of ER stress-mediated NLRP3 inflammasome overactivation.