Protective Effects of Astragali Radix on Cell Apoptosis in Denervated Skeletal Muscle in Rat

OBJECTIVE To study the influence of Astragali Radix upon apoptosis in denervated skeletal muscle atrophy at the early stage of peripheral never injury in rats.METHODS 54 male SD rats were randomized into 3 groups.In positive control group,the sciatic nerve was transected and prevented form regenerating.In experimental model group,the sciatic nerve were transected,and Astragali Radix was performed.In negative control group,the gastrocnemius were removed 2,14 and 28 days later.Muscle-wet weight(GAS) and body mass(BM) are weighed.The ratio of muscle wet weight served as the degree of muscle atrophy.A search for marker of apoptosis,nuclear DNA fragmentation,using terminal deoxyribonucleotidyl transferase mediated dUTP nick end labeling(the TUNEL medthod) in situ.Another portion of gastrocnemius muscle was homogenized and then analysed the activity of caspase-8 and caspase-9 by spectrophotometry.RESULTS The experimental model group had a higher ratio of muscle wet weight comparing with positive control group at the same time points(P0.05).TUNEL labeling of fragmented DNA on histological sections in experimental model group revealed higher levels of apoptotic nuclei than negative control group,but lower than positive control group at the early stage(P0.05).The activity of caspase-8 and caspase-9 in experimental model group is also higher than positive control group,lower than negative control group(P0.05).CONCLUSION Astragali Radix can significantly retard denervated skeletal muscle atrophy at the initial stage of peripheral never injury in rat and has protective effect on skeletal muscle cell apoptosis after peripheral never injury in rats.