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

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.

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.

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).

In conclusion, carvacrol improved the behavioral consequences of LPS challenge and attenuated neuroinflammation and brain tissue oxidative stress in rats.