Ameliorative effects of sinapic acid against vancomycin-induced testicular oxidative damage, apoptosis, inflammation, testicular histopathologic disorders and decreased epididymal sperm quality

In this study, it was aimed to determine the effect of sinapic acid (SNP), a polyphenol with antioxidant, anti-inflammatory and antibacterial properties, on testicular damage caused by vancomycin (VCM), a widely used antibiotic against gram positive bacteria. A total of 35 male Sprague Dawley rats were used in the study, divided into five groups: control, VCM, SNP, VCM + SNP 10, and VCM + SNP 20. Following a week of oral administration, the rats were euthanized under sevoflurane anesthesia. While the VCM group had a significant increase in MDA levels, the SNP administration inhibited the increase in MDA levels. VCM led to a significant decrease in GSH levels, SOD, CAT, and GPx activity in the testicular tissue of rats, while SNP administration increased these antioxidant levels. SNP administration decreased the mRNA expression levels of VCM induced Nrf-2, HO-1, and NQO1 in testicular tissue while increasing the levels of MAPK14, MAPK15, JNK, P53, Apaf-1, Caspase-3, Caspase-6, Caspase-9, and Beclin-1 mRNA transcript levels. The VCM group showed a significant increase in Bax and NF-κB levels in testicular tissue, while Bcl-2 levels decreased. VCM significantly decreased sperm motility and increased the percentage of damaged sperm in rats. Histopathological results revealed that VCM caused disruption of basement membranes and disorganization of seminiferous tubules, but SNP administration preserved testicular histology. As a result, VCM increased oxidative stress, apoptosis, and autophagy in the testicular tissue of rats, altered testicular histopathology, and decreased sperm quality, while SNP decreased these effects.