title: Preventive effects of bitter melon (Momordica charantia) against insulin resistance and diabetes are associated with the inhibition of NF-κB and JNK pathways in high-fat-fed OLETF rats.
abstract: Bitter melon (BM; Momordica charantia) has been used as a treatment method for various diseases including cancer and diabetes. The objective of this study was to investigate whether BM has preventive effects against insulin resistance and diabetes and to identify the underlying mechanism by which BM ameliorates insulin resistance in obese and diabetic rats. The rats were separated into three groups as follows: (a) high-fat (HF) diet control, (b) HF diet and 1% BM and (c) HF diet and 3% BM. After 6 weeks of assigned treatments, body weight and food intake were not altered by BM administration. Bitter melon treatment significantly improved glucose tolerance and insulin sensitivity. The levels of proinflammatory cytokines were significantly down-regulated in liver, muscle and epididymal fats from BM-treated rats. The activation of nuclear factor-κB (NF-κB) in the liver and muscle was decreased by BM compared with HF controls. The 3% BM supplementation significantly increased the levels of phospho-insulin receptor substrate-1 (Tyr612) and phospho-Akt (Ser473). It also significantly decreased the levels of phospho-NF-κB (p65) (Ser536) and phospho-c-Jun N-terminal kinase (JNK) (Thr183/Tyr185) in liver, muscle and epididymal fats. The findings of this study indicate that BM exerted preventive effects against insulin resistance and diabetes through the modulation of NF-κB and JNK pathways. Therefore, BM may be useful in the prevention of insulin resistance and diabetes.
authors.affiliation: Department of Food and Nutrition and Human Ecology Research Institute, Chonnam National University, Gwangju, Korea.
authors.forename: Soo Jin
authors.initials: SJ
authors.lastname: Yang
authors.affiliation: Diabetes Research Institute, Sungkyunkwan University School of Medicine, Kangbuk Samsung Hospital, Seoul, Korea.
authors.forename: Jung Mook
authors.initials: JM
authors.lastname: Choi
authors.affiliation: Department of Endocrinology and Metabolism, Sungkyunkwan University School of Medicine, Kangbuk Samsung Hospital, Seoul, Korea.
authors.forename: Se Eun
authors.initials: SE
authors.lastname: Park
authors.affiliation: Department of Endocrinology and Metabolism, Sungkyunkwan University School of Medicine, Kangbuk Samsung Hospital, Seoul, Korea.
authors.forename: Eun Jung
authors.initials: EJ
authors.lastname: Rhee
authors.affiliation: Department of Endocrinology and Metabolism, Sungkyunkwan University School of Medicine, Kangbuk Samsung Hospital, Seoul, Korea.
authors.forename: Won Young
authors.initials: WY
authors.lastname: Lee
authors.affiliation: Department of Endocrinology and Metabolism, Sungkyunkwan University School of Medicine, Kangbuk Samsung Hospital, Seoul, Korea.
authors.forename: Ki Won
authors.initials: KW
authors.lastname: Oh
authors.affiliation: Department of Endocrinology and Metabolism, Sungkyunkwan University School of Medicine, Kangbuk Samsung Hospital, Seoul, Korea.
authors.forename: Sung Woo
authors.initials: SW
authors.lastname: Park
authors.affiliation: Department of Endocrinology and Metabolism, Sungkyunkwan University School of Medicine, Kangbuk Samsung Hospital, Seoul, Korea. Electronic address: cydoctor@chol.com.
authors.forename: Cheol-Young
authors.initials: CY
authors.lastname: Park
mesh_terms: D052436:Adipose Tissue, White / Q000276:immunology / Q000378:metabolism; D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000008:administration & dosage / Q000627:therapeutic use; D002467:Cell Nucleus / Q000276:immunology / Q000378:metabolism; D016207:Cytokines / Q000037:antagonists & inhibitors / Q000378:metabolism; D003924:Diabetes Mellitus, Type 2 / Q000209:etiology / Q000517:prevention & control*; D059305:Diet, High-Fat / Q000009:adverse effects; D019587:Dietary Supplements; D005638:Fruit / Q000737:chemistry; D007004:Hypoglycemic Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D007333:Insulin Resistance; D048031:JNK Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D008099:Liver / Q000276:immunology / Q000378:metabolism; D020935:MAP Kinase Signaling System; D008297:Male; D029777:Momordica charantia / Q000737:chemistry*; D018482:Muscle, Skeletal / Q000276:immunology / Q000378:metabolism; D016328:NF-kappa B / Q000037:antagonists & inhibitors / Q000378:metabolism; D009765:Obesity / Q000209:etiology / Q000276:immunology / Q000378:metabolism / Q000503:physiopathology*; D010936:Plant Extracts / Q000008:administration & dosage / Q000627:therapeutic use*; D021381:Protein Transport; D020334:Rats, Inbred OLETF
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D016207:Cytokines; D007004:Hypoglycemic Agents; D016328:NF-kappa B; D010936:Plant Extracts; D048031:JNK Mitogen-Activated Protein Kinases
keywords: Bitter melon; Glucose tolerance; Inflammation; Insulin resistance; Obesity