The effect of calcineurin activator, extracted from Chinese herbal medicine, on memory and immunity in mice.

Calcineurin (CN) is a highly abundant phosphatase in the brain and it is the only Ca(2+)- and calmodulin-dependent protein serine/threonine phosphatase. There is considerable evidence to suggest that CN plays an essential role in activity-dependent modulation of synaptic efficacy. It has been shown recently that inhibitors of CN, such as CsA or FK506, impair memory formation in day-old chicks. In our present study, extract of Fructus cannabis (EFC) with activation of CN, extracted from Chinese traditional medicine, was used to determine the effects on memory and immunity. In the step-down-type passive avoidance test, the plant extract (0.2 g/kg) significantly improved amnesia induced by chemical drugs in mice, and greatly enhanced the ability of cell-mediated type hypersensitivity and nonspecific immune responses in normal mice. The present study provided pharmacological evidence for Chinese herbal medicine screening from molecular model.

Extract from Fructus cannabis activating calcineurin improved learning and memory in mice with chemical drug-induced dysmnesia.

AIM: To investigate the effects of extract from Fructus cannabis (EFC) that can activate calcineurin on learning and memory impairment induced by chemical drugs in mice. METHODS: Bovine brain calcineurin and calmodulin were isolated from frozen tissues. The activity of calcineurin was assayed using p-nitrophenyl phosphate (PNPP) as the substrate. Step-down type passive avoidance test and water maze were used together to determine the effects of EFC on learning and memory dysfunction. RESULTS: EFC activated calcineurin activity at a concentration range of 0.01-100 g/L. The maximal value of EFC on calcineurin activity (35 %+/-5 %) appeared at a concentration of 10 g/L. The chemical drugs such as scopolamine, sodium nitrite, and 45 % ethanol, and sodium pentobarbital induced learning and memory dysfunction. EFC administration (0.2, 0.4, and 0.8 g/kg, igx7 d) prolonged the latency and decreased the number of errors in the step-down test. EFC, given for 7 d, enhanced the spatial resolution of amnesic mice in water maze test. EFC overcome amnesia of three stages of memory process at the dose of 0.2 g/kg. CONCLUSION: EFC with an activation role of calcineurin can improve the impaired learning and memory induced by chemical drugs in mice.