Protective effects of hops (Humulus lupulus L.) extract on analgesic activity and oxidative stress markers in the brain of rats with carrageenan-induced paw edema

Abstract

Hops (Humulus lupulus L.) are widely utilized worldwide as a raw material for various medical applications due to their numerous beneficial health effects. This study aimed to assess the potential neuroprotective effects of hop extract on cerebral oxidative markers and pain using rat models. In the experimental study, rats were divided into five groups and administered varying doses of Humulus lupulus L. extract (HLE) for a period of 15 days prior to the administration of carrageenan. To induce acute inflammation in rats, carrageenan (1 %) was injected into the sub-plantar region of the left paw. Subsequently, analgesic responses, the antioxidant activity and lipid peroxidation in the cerebral cortex were assessed. In the investigation of pain tolerance caused by inflammation in the hot plate test, the HLE treatment groups as exhibited a significant increase (P < 0.001) in delay time for removing the paw from the hot plate compared to the carrageenan group. The results demonstrate that HLE treatment significantly increased the activity of CAT (P < 0.001) and SOD (P < 0.01) enzymes, while decreasing the level of MDA (P < 0.01). It can be concluded that the consumption of hops may alleviate pain caused by inflammation and mitigate cerebral oxidative stress in rats.