The Protective Effects of Zanthoxylum bungeanum Maxim Pharmacopuncture on Disuse Muscle Atrophy in Rat Gastrocnemius Muscle

Abstract

Background: This study aimed to investigate the protective effects of Zanthoxylum bungeanum Maxim pharmacopuncture on disuse muscle atrophy in the gastrocnemius muscle of rats. Methods: Thirty male 250 g Sprague-Dawley rats were distributed randomly into 3 groups. The left hindlimb immobilization was performed with casting tape for 2 weeks, and no treatment was given to the right hindlimb. Rats received pharmacopuncture and were injected daily on the BL57 with either 2 mL of Zanthoxylum bungeanum Maxim aqueous extract (ZM-W group), 1 mL pharmacopuncture of Zanthoxylum bungeanum Maxim ethanol extract (ZM-E group), or 2 mL normal saline (control group). After 2 weeks of immobilization, the weight of the whole gastrocnemius muscle was measured, and the morphology of both the left and the right gastrocnemius muscles were assessed by Hematoxylin and Eosin staining. To investigate the immobilization-induced muscular apoptosis, the immunohistochemical analysis of BAX and Bcl-2 was carried out. Results: ZM-W and ZM-E significantly inhibited the reduction in weight of the left gastrocnemius muscle, the reduction in the left myofibrils, and the cross-sectional area of gastrocnemius, as compared with the control. Moreover, the ZM-W and ZM-E groups showed significantly reduced immunoreactivity for BAX, and increased immunoreactivity of Bcl-2 in left gastrocnemius muscle compared with the control group. Conclusion: These results suggest that Zanthoxylum bungeanum Maxim pharmacopuncture has protective effects against immobilization-induced muscle atrophy by regulating the activity of apoptosis-associated BAX / Bcl-2 proteins in the gastrocnemius muscle.