Curcumin alleviates heatstroke-induced liver injury in dry-heat environments by inhibiting the expression of NF-κB, iNOS, and ICAM-1 in rats

Abstract

we aimed to monitor liver injury in rat model during heat stress and heatstroke in dry-heat environment and investigate the effects of curcumin on heatstroke-induced liver injury and the underlying mechanisms. Sprague-Dawley (SD) rats were randomly divided into four groups: normal saline (NS), and 50 (50-cur), 100 (100-cur), and 200 mg/kg curcumin (200-cur) groups. They were administered the indicated doses of curcumin by gavage once daily for 7 days. On day 8, the rats were transferred to a simulated climate cabin, At 0, 50, 100, and 150 min, the core temperature (Tc) was measured respectively. After sacrificing the rats, tissue samples were collected, measure histology indices, serum enzymes, lipopolysaccharides (LPSs), cytokines, nuclear factor-kappa B (NF-κB), inducible nitric oxide synthase (iNOS), and intercellular adhesion molecule-1 (ICAM-1). The Tc increased with time in all groups. Curcumin alleviation of symptoms and improvement in pathological scores. The level of enzymes, LPS, and cytokines increased during heatstroke in the NS group, but curcumin decreased the levels of these indicators. The differences of the indicators between NS and 200-cur groups at 150 min were significant (P < 0.05). The expression of NF-κB p65, iNOS, and ICAM-1 was upregulated in the NS group at 150 min, but their expression was relatively lower in the curcumin groups (P < 0.05). Thus, our findings indicate acute liver injury during heat stress and heatstroke. The mechanism involves cascade-amplification inflammatory response induced by the gut endotoxin. Furthermore, curcumin alleviated heatstroke-induced liver injury in a dose-dependent manner by downregulating NF-κB, iNOS, and ICAM-1.