[Effect and mechanism of moxibustion on oxidative stress injury in rats with Parkinson's disease by activating Nrf2/ARE pathway].

Objective: To observe the effect of moxibustion on oxidative stress injury of nigrostriatal system in rats with Parkinson's disease (PD) based on nuclear factor erythroid 2-related factor (Nrf2)/antioxidant response element (ARE) pathway, and to explore its mechanism.

Methods: A total of 48 SD rats were randomized into a blank group, a sham-operation group, a model group and a moxibustion group, 12 rats in each group. Unilateral two-point injection with 6-hydroxydopamine (6-OHDA) was adopted in the model group and the moxibustion group to establish the PD model; the operation manipulation in the sham-operation group was the same as the model group and the moxibustion group, and the same volume of 0.9% sodium chloride solutions was given by unilateral two-point injection. Moxibustion was adopted at "Baihui" (GV 20) and "Sishencong" (EX-HN 1) in the moxibustion group for 20 min, once a day, 6 times a week for 6 weeks. No intervention was given in the other 3 groups. Morphology of right mesencephalon substantia nigra was observed by HE staining, the expression of tyrosine hydroxylase (TH) in right mesencephalon substantia nigra was detected by immunohistochemistry method, the expression of reactive oxygen species (ROS), malondialdehyde (MDA), glutathione (GSH), and glutathione peroxidase (GSH-Px) in corpus striatum was detected by colorimetry method, and the expression of Nrf2 and heme oxygenase-1 (HO-1) proteins was detected by Western blot in the 4 groups.

Results: Clear tissue structure and complete dopaminergic neurons of right mesencephalon substantia nigra were observed in the blank group and the sham-operation group; unclear tissue structure, decreased and swelling dopaminergic neurons were observed in the model group; compared with the model group, more neurons were observed and the swelling of cyton was reduced in the moxibustion group. Compared with the sham-operation group, the expression of TH in right mesencephalon substantia nigra was decreased in the model group (<0.01); compared with the model group, the expression of TH in right mesencephalon substantia nigra was increased in the moxibustion group (<0.05). Compared with the sham-operation group, the expression of ROS, MDA was increased (<0.01), the expression of GSH, GSH-Px, Nrf2 and HO-1 was decreased in the model group (<0.01, <0.05); compared with the model group, the expression of ROS, MDA was decreased (<0.05, <0.01), the expression of GSH, GSH-Px, Nrf2 and HO-1 was increased in the moxibustion group (<0.05, <0.01).

Conclusion: Moxibustion can alleviate oxidative stress injury of nigrostriatal system in rats with Parkinson's disease by activating the Nrf2/ARE pathway, and protect the dopamine neurons.