[Effect and mechanism of curcumin on learning and memory dysfunction induced by gp120 in rats].

AIM: To explore the effect and mechanisms of curcumin on learning and memory dysfunction induced by HIV-1 enveloped protein gp120. METHODS: The SD rats were treated with gp120 by intracerebroventricular (ICV) infusion imitating the HIV-1 associated dementia (HAD) animal model. Subsequently, we applied the water maze test to evaluate the effect of gp120 on the learning and memory dysfunction in rats. The SD rats were divided into six groups: control group, sham group, model group, low dose curcumin group, middle dose curcumin group and high dose curcumin group. Except control and sham group, the others four groups received slowly 5 microL/d gp120 which dissolved in artificial cerebrospinal fluid (ACSF) for 3 days. Since the fourth day, the rats of low, middle, high dose curcumin groups were treated with 50 mg/(kg.d), 100 mg/(kg.d), 200 mg/(kg.d) curcumin, respectively. The others groups were treated with redistilled water. The treatment lasted for 14 days. Subsequently, the water maze test and NMDA2BR immunohistochemical staining were applied to evaluate the effect of curcumin on the rats. RESULTS: The rats were treated with gp120 50 ng/d by ICV infusion for 3 days can imitate the HAD animal model. The Morris water maze (MWM) test showed that the rats in model group had longer escape latencies compared with those in control group (P<0.05) and that rats in low, middle, high dose curcumin groups had shorter escape latencies compared with those in model group (P<0.05), and low dose curcumin group was better than the other two groups (P<0.05). Immunohistochemical staining showed that the expressions of NMDA2BR in model group decreased compared with the control groups (P<0.01), while the expressions of NMDA2BR in low, middle and high dose curcumin groups increased compared with the model groups. CONCLUSION: The SD rats were treated with gp120 by ICV infusion imitating the HAD animal model. The curcumin can improve the learning and memory dysfunction induced by gp120, the mechanism may be related to against the downregulation the expression of NMDA2BR.