The effect of Cannabis sativa leaves extract on memory retention in alzheimeric adult male rats

Cannabis (Cannabis sativa L.) has long been known to have analgesic, immunomodulatory and anti-inflammatory effects. Cannabinoids are a group of C21 terpenophenolic compounds uniquely produced by Cannabis sativa plant. In the present study, the effect of cannabis ethanolic extract on neurodegeneration induced by intracerebroventricular (ICV) administration of streptozotocin (STZ), was investigated in adult male Wistar rats. The rats were randomly divided into 9 groups: normal control, Sham-operated control (saline, ICV), cannabis extract (0.05, 0.1, and 0.2 g/kg intragastrically, daily) alone, alzhiemeric control rats (STZ, 110 mg/ml, 3 μ/site, ICV), cannabis extract (0.05, 0.1, and 0.2 g/kg intragastrically, daily) together with STZ, and treatment was performed accordingly. Animals were injected with STZ bilaterally, on the 1st and 3rd days. Administration of cannabis extract (0.05, 0.1 and 0.2 g/kg) was started 1 h before the first dose of STZ and continued up to 30 days. The learning and memory behavior was assessed by a passive avoidance test 30 days after the first dose. The rats were sacrificed on day 31 and parameters of oxidative stress, superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX) and malondialdehyde (MDA) activity, were measured in brain homogenate. Also TNF-α and activated protein of ϒ-secretase level were measured in brain homogenate. Histopathological changes were examined by Bielschowsky staining. Our results showed that administration of cannabis extract (0.1 and 0.2 g/kg) significantly improved STZ-induced cognitive impairment. Cannabis extract increased the levels of antioxidant enzymes, including SOD, CAT, GPX, while decreased MDA levels. Also, cannabis extract decreased the levels of TNF-α and activated protein of ϒ-secretase in brain homogenate. Histopathological examination showed that cannabis extract decreased cell loss in cerebral cortex and hippocampus in Alzhiemeric rats. These results indicate that cannabis extract is effective in providing protection against memory deficit, oxidative stress, and neuronal damage induced by STZ.

کلیدواژه ها:

Cannabis ، Cannabis sativa L. ، Memory ، Streptozotocin ، Rat