Effect of High Doses of Salep Aqueous Extract on Serum Levels of Urea Nitrogen, Creatinine, Uric Acid, and Kidney Histopathological Changes in Adult Male Wistar Rats

Kidneys are critical in the clearance and maintenance of active metabolites. One of the medical properties of Salep is treating bladder and kidney inflammation. Due to the widespread use of Salep in traditional medicine and the food industry, and since the effects of Salep on kidney function have not been studied, the present study aimed to investigate the impact of Salep on kidney function. In this experimental study, 48 male rats were divided randomly into six groups as control, sham, and four experimental groups receiving different doses of Salep intraperitoneally (80, 160, 320, and 640 mg/kg). On day 29, after weighing the animals, blood samples were taken from the heart, and serum blood urea nitrogen (BUN), uric acid, and creatinine were analyzed and compared in different groups. All the animal's kidneys were exposed after dissection, and tissue sections were prepared for histopathological evaluation. From day 28 to 29, rats were kept in metabolic cages to collect urine samples and measure water intake and urine volume. The serum concentration of BUN and uric acid in the groups receiving Salep at all doses decreased non-significantly compared to the control group. Furthermore, a significant reduction was seen in creatinine serum levels in groups receiving 320 and 640 mg/kg of Salep extract (<0.05). No evidence of damage to renal tissue was observed in this study. In conclusion, Salep could decrease serum BUN, uric acid, and creatinine levels due to its antioxidant properties and had no devastating effect on kidneys.