Cedrol supplementation ameliorates memory deficits by regulating neuro-inflammation and cholinergic function in lipopolysaccharide-induced cognitive impairment in rats

Background: Cedrol, a sesquiterpene alcohol, is found in a high amount in several conifers. It possess several beneficial health effects, including antioxidant and anti-inflammatory properties. Objective: This study evaluates the neuroprotective role of cedrol against lipopolysaccharide (LPS)-induced neuroinflammation and memory loss in rats.

Methods: Wistar rats were treated with cedrol (7.5, 15, and 30 mg/kg, oral, two weeks). During the last week, the rats (except for the control group) were treated with LPS (intraperitoneal injection, 1 mg/kg) to induce memory impairment. After that, the animals were subjected to behavioral studies (Morris water maze and passive avoidance) and biochemical assessments.

Results: Our results showed a significant decrease in learning and memory function-in LPS-induced rats which were reversed by cedrol. Also, there was a significant increase in the cerebral levels of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and malondialdehyde (MDA) as well as acetylcholinesterase (AChE) activity in LPS-treated rats. Besides, a significant reduction in total thiol and superoxide dismutase levels was observed in LPS-treated rats. However, cedrol significantly decreased the brain level of AChE, TNF-α, and IL-1β. Administration of cedrol also restored the oxidative stress markers.

Conclusion: the beneficial effects of cedrol against LPS-induced memory impairment could be due to antioxidant activities and modulation of neuro-inflammatory mediators.