Delaying denervated skeletal muscle atrophy by Radix Astragali via the NF-kappaB/MuRF1 pathway

Objective To study the influence of Radix Astragali on the expression of nuclear factor of kappaB (NF-kappaB)p65 and muscle RING finger protein l(MuRF1)and explore the preventive and therapeutic effect and mechanisms of Radix Astragali on prevention of denervation muscle atrophy. Methods Denervation of the right gastrocnemius muscle was created in 54 Wister rats. The animals were randomized into Radix Astragali treatment group and control group. Levels of NF-kappaB p65 and MuRF1 mRNA and protein in the gastrocnemius muscle at 2, 7, 14 and 28 days after denervation were detected by RT-polymerase chain reaction (RT-PCR)and Western Blot. The ratio of muscle wet weight was also analyzed for comparison. Results After gastrocnemius muscle denervation, the levels of NF-kappaB p65 and MuRFl mRNA and protein increased with time( P < 0.05). On the 7th , 14th and 28th day after denervation muscle wet weight of the Radix Astragali treated group was heavier than that of the control group (P < 0.05), while expression of NF-kappaB and MuRFl was remarkably lower than that of the control group at the same time points( P < 0.05) . Conclusion Radix Astragali can significantly delay atrophy of denervated skeletal muscle. This effect may be related with its inhibition of the NF-kappaB/MuRFl pathway. Key words: Muscular atrophy;  Astragalus membranaceus;  Nuclear factor of kappaB;  Muscle RING finger protein 1