The hepato-renal protective potential of walnut seed skin extract against acute renal ischemia/reperfusion damage

Abstract

Acute kidney damage is defined as a sudden change in kidney functions that prevents the removal of nitrogenous wastes from the body, thus disrupting the body's fluid and electrolyte balance. When acute kidney injury occurs, the kidneys and liver are most affected in the body. Agents used in the treatment of acute kidney injury often have nonsteroidal anti-inflammatory properties that can produce toxic effects on the gastrointestinal tract and kidneys. Natural antioxidants can be recommended as an alternative to existing treatment or in combination to protect tissues against these toxic effects. Therefore, we conducted our current study on whether walnut seed skin (WSS) extract might have hepato-renal protective effects in kidney-damaged Sprague-Dawley rats. This study is the first to use walnut seed skin extract in liver and kidney tissues in renal ischemia/reperfusion (IR) injury. Female Sprague-Dawley rats were randomly divided into three groups: Healty control (HC), renal IR (50 min ischemia - 3 h reperfusion), and renal IR + 450 mg/kg/p.o. WSS extract (the rats were treated with WSS extract orally once 1 h before the IR procedure). For this purpose, blood, liver and kidney tissues of rats were used. In serum samples, aspartate aminotransferase (AST), alanine aminotransferase (ALT), lactate dehydrogenase (LDH), urea and creatinine values were determined separately for the administration groups. We also performed histopathological studies on liver and kidney tissues. Finally, gene markers (endothelial nitric oxide synthase (eNOS), interleukin-6 (IL-6), tumor necrosis factor alpha (TNF-α), Caspase-4 and Caspase-9) determined to evaluate the anti-oxidant, anti-inflammatory and apoptotic effect of walnut seed skin were measured by q-RT PCR method. As a result of the study it was determined that pre-application of WSS extract improved the deteriorated serum parameters in rats with renal ischemia. In the histopathological analysis results, it was observed that WSS had a protective effect on kidney and liver tissue. In studies on gene expression, although there were different and contradictory results for liver and kidney tissue, we determined that WSS was more protective on liver tissue. In conclusion, the healing potential of WSS in renal and hepatic tissues seems to act by inhibiting the inflammatory response, oxidative stress and apoptosis. Therefore, the potential of this extract is remarkable and may serve as a potential therapeutic that may protect against acute organ damages due to renal IR.

Keywords: Apoptosis; Inflammation; Ischemia/reperfusion; Walnut Seed Skin; q-RT PCR.