Sulforaphane (Sul) reduces renal interstitial fibrosis (RIF) by controlling the inflammation and TGF-β/Smad signaling pathway

Abstract

All chronic renal disorders eventually lead to renal interstitial fibrosis (RIF). Chronic inflammation and pro-fibrotic substances are familiar companions of the fibrotic process. The Sulforaphane (Sul) molecule is particularly useful in protecting the liver from oxidative damage. To investigate the Sul effects on fibrosis markers and inflammatory proteins in the kidney of NRK52E cell line and rats and clarify the mechanism of TGF-β/Smad signaling pathway in a rat model of RIF were developed in the present study. Sul (50, 100, and 200 ng/ml) remarkably reduced the gene expressions of tumor necrosis factor (TNF-α), interleukin-6 (IL-6), interleukin (IL)-1β, collagen 3 (COL3A1), collagen 1 (COL1A1), and α-smooth muscle actin (α-SMA) in fibrotic NRK52E cells compared with those in cells inspired by transforming growth factor-α (TGF-α). Histopathological investigations showed that Sul administration retained renal tissue structure and decreased kidney tissue fibrosis in rats subjected to unilateral ureteral blockage (UUO). The expression level of TNF-α, IL-6, IL-1β, COL3A1, COL1A1, and α-SMA in the rats’ kidneys exposed to UUO was also suppressed by the treatment of Sul. In the present study, western blot analysis showed that Sul upregulated the expressions of fibrotic NRK52E cells Smad7 and rat model UUO groups while simultaneously decreasing the stimulation of Smad2/3 and the expressions of cyclooxygenase-2, NF-κB, Smad4, activator protein-1, and high-mobility group protein B1. Ultimately, Sul’s ability to inhibit the TGF-β/Smad pathway and the development of inflammation factors may mitigate RIF.