title: Emodin ameliorates high-fat-diet induced insulin resistance in rats by reducing lipid accumulation in skeletal muscle.
abstract: Emodin, an anthraquinone derivative isolated from root and rhizome of Rheum palmatum, has been reported to have promising anti-diabetic activity. The present study was to explore the possible mechanism of emodin to ameliorate insulin resistance. Insulin resistance was induced by feeding a high fat diet to Sprague-Dawley rats. The blood glucose and lipid profiles in serum were measured by an enzymatic method, and a hyperinsulinaemic-euglycaemic clamp was used to evaluate insulin resistance. L6 cells were cultured and treated with palmitic acid and emodin. The lipid content was assayed in the soleus muscle and L6 cells by Oil Red O staining. Western blot, qRT-PCR, and immunohistochemical staining were used to detect the following in the rat soleus muscle and L6 cells: protein levels, mRNA levels of FATP1, FATP4, transporter fatty acid translocase (FAT/CD36), and plasma membrane-associated fatty acid protein (FABPpm). We found that blood glucose, triglyceride (TG), total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) were significantly decreased in the emodin group. Oil Red O staining and the level of TG in skeletal muscle and L6 cells confirmed that lipid deposition decreased after treatment with emodin. Furthermore, the protein levels and mRNA levels of FATP1 in skeletal muscle and in L6 cells of rats were significantly decreased, yet the protein levels and mRNA levels of FATP4, FAT/CD36 and FABPpm did not drop off significantly. The study suggest that emodin ameliorates insulin resistance by reducing FATP1-mediated skeletal muscle lipid accumulation in rats fed a high fat diet.
authors.affiliation: Department of Pharmacy, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, People's Republic of China.
authors.forename: Yanni
authors.initials: Y
authors.lastname: Cao
authors.affiliation: Department of Obstetrics and Gynecology, The Second Affiliated Hospital of Chongqing Medical University, Chongqing 400016, People's Republic of China.
authors.forename: Shufang
authors.initials: S
authors.lastname: Chang
authors.affiliation: Department of Pharmacy, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, People's Republic of China.
authors.forename: Jie
authors.initials: J
authors.lastname: Dong
authors.affiliation: Department of Pharmacy, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, People's Republic of China. Electronic address: zhushenyin0486@sina.com.
authors.forename: Shenyin
authors.initials: S
authors.lastname: Zhu
authors.affiliation: Department of Pharmacy, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, People's Republic of China.
authors.forename: Xiaoying
authors.initials: X
authors.lastname: Zheng
authors.affiliation: Department of Pharmacy, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, People's Republic of China.
authors.forename: Juan
authors.initials: J
authors.lastname: Li
authors.affiliation: Department of Pharmacy, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, People's Republic of China.
authors.forename: Rui
authors.initials: R
authors.lastname: Long
authors.affiliation: Department of Pharmacy, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, People's Republic of China.
authors.forename: Yuanda
authors.initials: Y
authors.lastname: Zhou
authors.affiliation: Department of Pharmacy, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, People's Republic of China.
authors.forename: Jianyu
authors.initials: J
authors.lastname: Cui
authors.affiliation: Department of Pharmacy, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, People's Republic of China.
authors.forename: Ye
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D000818:Animals; D018955:CD36 Antigens / Q000378:metabolism; D059305:Diet, High-Fat / Q000009:adverse effects; D004642:Emodin / Q000494:pharmacology*; D050612:Fatty Acid Transport Proteins / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects; D007333:Insulin Resistance; D050356:Lipid Metabolism / Q000187:drug effects*; D008055:Lipids / Q000097:blood; D008297:Male; D018482:Muscle, Skeletal / Q000187:drug effects* / Q000378:metabolism*; D019308:Palmitic Acid / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D018955:CD36 Antigens; D050612:Fatty Acid Transport Proteins; D008055:Lipids; D019308:Palmitic Acid; D004642:Emodin
keywords: Emodin; FATP1; Insulin resistance; Lipid accumulation; Skeletal muscle