Effects Of Different Compatibility Proportion Of The Couplet Medicines For Radix Astragali And Angelica Sinensis On Disuse Muscle Atrophy

Background:Preious studies on human or animal showed that disuse muscle atrophy occurs as the consequences of bed rest, immobilization or space flight. It needs to take long time for the recovery of muscle following atrophy. Disuse atrophy could impair the movement ability of theastronauts and threaten their security. Clinically, long period of bed rest or inactivity also results in disuse atrophy, which negatively affects the quality of life and hinders rehabilitation.Although disuse atrophy is a common clinical complication, currently there are limited treatment options to prevent skeletal muscle atrophy. The development of therapeutics atrophy is becoming urgent in aerospace and rehabilitation medicine fields.As characteristic drug for Chinese nation, Traditional Chinese medicine has been used in China for thousands of years. In recent years, traditional Chinese medicine is increasingly used for prevention or therapy of disuse muscle atrophy. For years of research, our laboratory has characterized several traditional Chinese medicine that could significantly prevent disuse muscle atrophy through promoting blood circulation and removing blood stasis or tonic, including Ligusticum chuanxiong, Angelica sinensis and Radix Astragali.The results of modern pharmacological researches indicated that due to difference in the effective components, Radix Astragali and Angelica sinensis have different targets, therefore, their compatibility takes the advantage of multiple therapeutic targets and proved better effective than single drug. The aim of the current study is to identify a couplet medicines composed of Radix Astragali and Angelica sinensis and investigate its curative effects and potential mechanisms on disuse muscle atrophy.Objective:1. By Comparing the effects of single Radix Astragali or Angelica on Soleus muscle(SOL) and extensor digitorum longus(EDL) from hindlimb unloading(HLU) rats to that of the couplet medicines, we aim to investigate the feasibility of the couplet medicines for cure of disuse muscle atrophy.2. By analyzing the effects of different compatibility proportion of the couplet medicines on SOL and EDL from HLU rats, we aim to confirm the best compatibility for cure of disuse muscle atrophy.3. By investigating the effects of the couplet medicines on protein expression of Bax and Bcl-2 in skeletal muscles of HLU rats, we aim to study the molecular mechanism of the couplet medicines against disuse muscle atrophy.Methods:1. Muscle fiber cross-sectional area and muscle fiber distribution were investigated using immunohistochemical method.2. The protein expressions of apoptosis factors Bax and Bcl-2 were measured using the Western-Blotting assay.Results:1. Compared with HLU+W group, the type Ⅰ muscle fibers Cross sectional area(CSA) of soleus muscle of the HLU+Rad, HLU+Ang and HLU+5R:1A groups were increased by 15.61% (P＜0.05),9.58% (P>0.05), and 56.32% (P＜0.001), respectively; the type Ⅱ muscle fiber CSA were increased by 76.63% (P＜0.001),64.74% (P＜0.001,) and 90.83% (P＜0.001), respectively; the percentage of type Ⅰ muscle fibers were increased by 26.38% (P＜0.01),17.67% (P＜0.05),33.38% (P＜0.001), respectively.2. Compared with HLU+W group, the type Ⅰ muscle fibers CSA of the HLU+5R:1A, HLU+1R:lA and HLU+1R:5A groups were increased by 37.94% (P＜0.001),28.92% (P＜0.05) and 56.41% (P＜0.001), respectively; the type Ⅱ muscle fiber CSA were increased by 79.38% (P＜0.001),70.83% (P＜0.001) and 90.28% (P＜0.001), respectively; the percentage of type Ⅰ muscle fibers increased by 12.14% (P＜0.05),10.40% (P＜0.05),33.38% (P＜0.01), respectively.3. Compared with HLU+W group, the protein expression of anti apoptosis factor Bcl-2 of the HLU+5R:1A group were increased by 6.88% (P>0.05)in SOL and 7.55% (P>0.05) in EDL; the expression of Bax were decreased by 42.89% (P＜0.01) in SOL and 0.24% (P>0.05) in EDL;the ratios of Bax/Bcl-2 in SOL and EDL were decreased by 34.50% (P＜0.01) and 18.33% (P＜0.05), respectively.Conclusions:1. The curative effect of the couplet medicines composed of Radix Astragali and Angelica sinensis on disuse muscle atrophy is better than single Radix Astragali or Angelica sinensis.2. The optimal ratio of the couplet medicines composed of Radix Astragali and Angelica sinensis for prevention of disuse muscle atrophy is 5 to 1.3. For the couplet medicines composed of Radix Astragali and Angelica sinensis, preserving protein mass by inhibiting of cell apoptosis induced by oxidative stress is an alternative molecular mechanism preventing disuse muscle atrophy, but not a major mechanism.