Rutin impedes indoleamine 2, 3-dioxygenase activity/expression to mitigate heat stress-mediated testicular dysfunction

Testicular heat stress (THS)-induced male reproductive dysfunction is a growing concern due to its link to rising male infertility associated with occupational and lifestyle factors. Rutin, a dietary flavonoid known for its anti-inflammatory and antioxidant properties, was evaluated for its potential to mitigate THS-mediated testicular damage, while vitamin e was used as a standard drug. Wistar rats exposed to scrotal hyperthermia showed that rutin significantly reduced oxidative-inflammatory damage, preserved testicular architecture, improved sperm parameters, and restored testosterone levels. Mechanistic studies demonstrated that rutin alleviated oxidative stress by enhancing antioxidant enzyme activities and reducing lipid peroxidation, as well as suppressing inflammatory responses and downregulated indoleamine 2, 3-dioxygenase (IDO) activity/expression. The results for the first time demonstrate rutin’s dual action of IDO inhibition and oxidative-inflammatory modulation making it a promising therapeutic agent for preventing heat stress-induced male infertility. Using molecular docking and molecular dynamics simulations, rutin was identified as a possible inhibitor of indoleamine 2,3-dioxygenase (IDO). These simulations revealed stable binding interactions between rutin and the active site of IDO1, further accentuating its inhibitory potential, which warrants further studies.