Carvacrol attenuated neuroinflammation, oxidative stress and depression and anxiety like behaviors in lipopolysaccharide-challenged rats

OBJECTIVE: The beneficial effect of carvacrol on neuroinflammation, oxidative damage of brain tissue, and depressive- and anxiety-like behaviors after lipopolysaccharide (LPS) administration were evaluated in rats. MATERIALS AND METHODS: Vehicle (1% Tween 80), 1 mg/kg of LPS, and carvacrol (25, 50, or 100 mg/kg administered prior to LPS) were injected and behavioral and biochemical tests were done. RESULTS: The results of forced swim test revealed that carvacrol attenuated immobility time and increased activity and climbing times (p<0.05 to p<0.001). The results of elevated plus maze also revealed that treatment by carvacrol prolonged the open arms time and entries and decreased the time and entries in the closed arms (p<0.05 to p<0.01). Carvacrol enhanced crossing, time, and traveled distance in the central segment of the open field and increased total crossing and distance while attenuating the peripheral zone time (p<0.05 to p<0.001). All doses of carvacrol attenuated TNF- α (tumor necrosis factor α) and NO (nitric oxide) in the brain (p<0.01 to p<0.001). The 50 and the 100 mg/kg doses of carvacrol decreased malondialdehyde (p<0.001 for both), and the 100 mg/kg dose of carvacrol increased the content of the thiol (p<0.001). CONCLUSION: In conclusion, carvacrol improved the behavioral consequences of LPS challenge and attenuated neuroinflammation and brain tissue oxidative stress in rats.