Gallic acid mitigates lipopolysaccharide-induced testicular inflammation via regulation of the NF-κB and PK2/PKR1 pathway.

Genital tract infections are common causes of male infertility, and most of diagnosed men are asymptomatic. This study examined the effect of gallic acid (GA) against lipopolysaccharide (LPS)-induced testicular inflammation. Thirty-two Spraque Dawley, 2.5-3 month-old male rats were separated into four groups (n = 8). Control group; saline at 3 ml/kg, and in the GA group; GA was dissolved in saline, by gavage at 100 mg/kg for 14 days. LPS group; LPS 5 mg/kg as a single dose was given intraperitoneal on the 11th day. LPS + GA group; GA was given for 14 days and LPS 5 mg/kg on the 11th day. After 72 h of LPS injection, all samples were collected. Semen analysis, biochemical assays, histological evaluations, and immunohistochemical or Western blot analyses for nuclear factor-kappa B (NF-κB) and Prokineticin 2/prokineticin receptor 1(PK2/PKR1) pathways were performed. There was a significant decrease in body and testicular weight, sperm parameters, serum testosterone level, mean seminiferous tubule diameter, germinal epithelial thickness, and Johnsen score in the LPS group compared to control and GA groups. However, a significant increase was found in interstitial space width, percentage of abnormal sperm, NF-κB and PK2 immunoreactivities, and expression of PK2 and PKR1 proteins. In the LPS + GA group, GA administration was observed to significantly prevent these adverse effects. In conclusion, the inhibitory effects of GA on the NF-κB and PK2/PKR1 pathways not only suppressed the inflammatory response but also restored impaired sperm parameters and testicular structure. These findings indicate GA's potential for treating testicular inflammation and protecting male reproductive health.