title: Bitter melon extracts in diabetic and normal rats favorably influence blood glucose and blood pressure regulation.
abstract: Bitter melon (BM) was tested in normal and streptozotocin (STZ)-induced diabetic rats. First, normal and diabetic Wistar rats were given four test extracts (EX-1-EX-4) of a wild-genotype BM or metformin by intubation. Second, normal Sprague-Dawley rats were divided into control and three test groups given for 52 days one of three BM preparations in food: Chinese or Indian commercial preparations or EX-4 from experiment I. In experiment I, extracts of BM administered at 50 mg/kg of body weight in normal rats reduced blood sugar for 4 hours without, unlike metformin, inducing hypoglycemia. In STZ-induced diabetic rats, two extracts administered at 250 mg/kg decreased glucose levels to values comparable to metformin at 150 mg/kg. At 4 hours, EX-1 and EX-4 significantly reduced blood glucose 67% and 63%, respectively, compared with metformin's 54%. In experiment II, all test groups had lowered systolic, but not diastolic, blood pressure. The China and EX-4 arms had significantly lowered serum glucose levels compared with the control. In the glucose tolerance test, only EX-4 had significantly lowered glucose levels. Only EX-4 had significantly lowered angiotensin converting enzyme (ACE) activity. All active arms showed significance in the losartan challenge (the renin-angiotensin system [RAS]), with the greatest effect in the EX-4 group. In the N(ω)-nitro-l-arginine-methyl ester challenge, only EX-4 exhibited a significant impact on the nitric oxide system, suggesting higher activity in this group. In the STZ-induced diabetic rat model, wild-type BM powerfully lowered glucose levels, and, in healthy adult rats, wild-type BM exhibited beneficial effects in the regulation of blood glucose, in RAS and ACE inhibition, and in nitric oxide generation.
authors.affiliation: Glykon Technologies Group, LLC, Santa Monica, California, USA. dallasclouatre@mac.com
authors.forename: Dallas L
authors.initials: DL
authors.lastname: Clouatre
authors.forename: Sadanand N
authors.initials: SN
authors.lastname: Rao
authors.forename: Harry G
authors.initials: HG
authors.lastname: Preuss
mesh_terms: D000818:Animals; D001786:Blood Glucose / Q000032:analysis / Q000187:drug effects*; D001794:Blood Pressure / Q000187:drug effects*; D019662:Cucurbitaceae / Q000737:chemistry*; D003921:Diabetes Mellitus, Experimental / Q000188:drug therapy* / Q000503:physiopathology; D005638:Fruit / Q000737:chemistry; D005951:Glucose Tolerance Test; D007004:Hypoglycemic Agents / Q000494:pharmacology*; D019808:Losartan / Q000494:pharmacology; D008297:Male; D008687:Metformin / Q000494:pharmacology; D019331:NG-Nitroarginine Methyl Ester; D009569:Nitric Oxide / Q000032:analysis / Q000378:metabolism; D010936:Plant Extracts / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D017208:Rats, Wistar; D012084:Renin-Angiotensin System / Q000187:drug effects
chemical_list: D001786:Blood Glucose; D007004:Hypoglycemic Agents; D010936:Plant Extracts; D009569:Nitric Oxide; D008687:Metformin; D019808:Losartan; D019331:NG-Nitroarginine Methyl Ester