[email protected] equallyKey words: Fructus Schisandrae, PP58 manufacturer muscle atrophy, dexamethasone,proteolysis, antioxidant effectsKIM et al: ANTIMUSCLE ATROPHY EFFECTS OF Fructus Dihydrofuran-3(2H)-one custom synthesis SchisandraeVarious animal models of skeletal muscle atrophy have already been employed in investigation, which includes unloading (8), immobilization (9), starvation (10), denervation (11) plus the administration of GLU (12). Among these, the administration of high concentrations of dexamethasone (a representative GLU) causes catabolic alterations in skeletal muscle, mainly as a result of the stimulation of muscle proteolysis. This GLUinduced protein degradation is mainly mediated by the activation of the ubiquitinproteasome and lysosomal pathways (13,14). In unique, the musclespecific E3ligases, atrogin1 and muscle RINGfinger protein1 (MuRF1), as well as the lysosomal enzyme, cathepsin L, are highly stimulated by GLUs (15,16). The upregulation of myostatin, a member on the transforming development factor (TGF) loved ones, is also a vital adverse regulator of skeletal muscle mass which is involved in GLUinduced catabolic muscle atrophy (17). These findings suggest that GLUinduced skeletal muscle atrophy may serve as a valuable and rapid animal model for screening agents that may avert abnormal catabolic muscle atrophy (18,19). The dried fruit of Schizandra chinensis Baillon (S. chinensis), Fructus Schisandrae (FS), is a wellknown standard herb applied for pharmacological purposes in Asian nations (e.g., Korea, China and Japan) and in Russia to raise physical functioning capacity and for its stressprotective effects against aseptic inflammation and heavy metal intoxication. It also has useful effects around the central nervous, sympathetic nervous, endocrine, immune, respiratory, cardiovascular and gastrointestinal systems. It inhibits the improvement of experimental atherosclerosis, controls blood sugar and acidbase balance, and regulates uterus myotonic activity (20,21). Also, current studies have recommended that FS exerts favorable effects on diabetes and related complications (2225) on account of its smooth muscle relaxant effects (26,27). Having said that, the effectiveness of FS administration inside the prevention of GLUinduced muscle atrophy remains unclear. The aim on the present study was to investigate the effects from the administration of FS ethanol extracts on dexamethasoneinduced skeletal muscle atrophy in vivo. Additionally, we evaluated the molecular mechanisms involved in dexamethasoneinduced muscle atrophy and also the inhibitory effects of FS on these molecular events, in an aim to figure out regardless of whether the administration of FS has therapeutic value as a treatment for GLUinduced muscle atrophy. Materials and procedures Test components. The fruits of S. chinensis have been collected from an area around the city of Mungyeong (Gyeongsangbukdo, Korea) and washed 3 times with tap water just before being stored at 20 . The frozen samples have been lyophilized and homogenized employing a grinder prior to extraction. The materials had been extracted with 20 ethanol (FS) at room temperature for 24 h. The extract answer was filtered and concentrated employing a rotary vacuum evaporator (Buchi Rotavapor R144, B hi Labortechnik AG, Flawil, Switzerland). Oxymetholone [17hydroxy2(hydroxymethylene)17methyl5androstane3one; Celltrion Pharm Inc., Jincheon, Korea], which can be an orally active 17alkylated anabolicandrogenic steroid, was used as the reference drug. Oxymetholone was dissolved at 5 mg/ml in distilled water and FS was dissolved at 50 mg/ml in dist.