Protecive effects of alpha-lipoic acid on brain substantia nigra dopaminergic neurons in rats with Parkinson' s disease and its action mechanism

doi:10.3969/j.issn.1002-7386.2017.14.006

Abstract：Objective To investigate the protecive effects of alpha-lipoic acid ( LA ) on brain substantia nigra dopaminergic neurons in rats with Parkinson 's disease ( PD) induced by rotenone, and to explore its action mechanism. Methods Sixty healthy male Wistar rats (3-month age) were randomly divided into three groups:control group, experimental group and drug intervention group, with 20 rats in each group. The rats in control group were given sunflower oil by subcutaneous injection, however, the rats in experimental group and drug intervention group were given rotenone by subcutaneous injection to establish PD models,moreover,the rats in drug intervention group were given LA simultaneously by peritoneal injection. The expression levels of tyrosine hydroxylase ( TH ) , transcription factor NF-E2 related factors, anti-oxidant response elements (Nrf2-ARE) and heme oxygenase 1 (HO-1) in brain substantia nigra of rats were detected by Western Blot,moreover, the levels of malondialdehyde ( MDA) and reduced glutathione ( GSH) in brain striatum of rats were detected by spectrophotometric method. Results The expression levels of TH protein in mesencephalon of rats in experimental group were significantly lower than those in control group (P<0. 05),however, the expression levels of TH protein in brain substantia nigra of rats in drug intervention group were significantly higher than those in experimental group (P<0. 05), but which in drug intervention group were significantly lower than those in control group (P<0. 05). The expression levels of Nrf2 and HO-1 protein in experimental group were significantly lower than those in control group (P<0. 05),however, which in drug intervention group were significantly higher than those in experimental group (P <0. 05),moreover,which in drug intervention group were significantly lower than those in control group (P<0. 05). As compared with those in control group, the levels of MDA in striatum tissues of rats in experimental group were significantly increased (P<0. 05),however, after drug intervention,the levels of MDA were significantly decreased (P<0. 05),but which were still significantly higher than those in control group (P<0. 05). As compared with those in control group, the levels of GSH in experimental group were significantly decreased (P<0. 01), however, after drug intervention,the levels of GSH were significantly increased (P<0. 05), but which were still significantly lower than those in control group (P<0. 05). Conclusion LA can effectively activate the Nrf2-ARE signal pathway to relieve the injury of dopaminergic neurons in brain of rats,moreover,which can improve the symptoms of PD.