Ameliorative effect of carveol on scopolamine-induced memory impairment in rats

Carveol is a naturally occurring terpenoid with antispasmodic, carminative, astringent, indigestion, and dyspepsia properties, as well as anti-diabetic, anti-oxidant, anti-hyperlipidemia, and anti-inflammatory properties in the liver. Research also suggests that it has memory-enhancing and anti-oxidant properties. The purpose of this research was to see whether carveol could protect rats against scopolamine-induced memory loss in a rat model.

Thirty male Sprague-Dawley rats (200-250 g) were grouped as the saline group receiving saline, disease group receiving scopolamine, and four treatment groups among which three groups received scopalamine+carveol and one group received scopalamine+donepezil for 28 days. Followed by in vitro, behavioral, anti-oxidant, and molecular studies were done. P<0.005 was considered statistically significant.

The in vitro assay showed that carveol caused diphenyl-1-picrylhydrazyl inhibition. In-vivo findings revealed that carveol (50, 100, and 200 mg/kg) significantly improved dementia by reducing escape latency and spending more time in the targeted quadrant in the Morris water maze test. Increased number of entries and percent spontaneous alterations were observed in rats' Y-maze test. In animal brain tissues, i.e., cortex and hippocampus, carveol enhanced glutathione, glutathione-s-transferase, catalase, and reduced lipid peroxide levels. Carveol also improved cellular architecture in histopathological examinations and decreased expression of inflammatory markers such as amyloid-beta, nuclear factor kappa light chain activated B cells, tumor necrosis factor-alpha, cyclooxygenase 2, prostaglandin E2, and interleukin-18, as evidenced by immunohistochemistry and enzyme-linked immunosorbent assays, as well as molecular investigations.

This study suggests that the compound could be potent against amnesia mediated through anti-oxidant, amyloid-beta inhibition, and anti-inflammatory pathways.