�Science.2001 Dec 7; 294(5549):2166-70
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| The effect of water extract of Cinnamon on dexamethasone induced diabetes in albino rats. | ||||||||||||||||||||||||||||||||||||||
| Shyamjith, Chakradhar U.S., Anoop C.H., N Nayak | ||||||||||||||||||||||||||||||||||||||
| Department of Pharmacology, KMC, Mangalore. | ||||||||||||||||||||||||||||||||||||||
| Introduction: | ||||||||||||||||||||||||||||||||||||||
| Elevated glucocorticoids in the body either endogenous (that is in Cushing?s syndrome) or exogenous (in the form of medication) increase insulin resistance and may precipitate diabetes mellitus1.Diabetes mellitus induced by glucocorticoids is similar to type 2 diabetes mellitus (T2DM) where insulin resistance forms an essential component. Further it may be mentioned that glucocorticoids also cause obesity, hypertension, hyperuricemia, increased plasminogen activator inhibitor-1, low HDL cholesterol along with glucose intolerance. The cluster of these abnormalities was coined as "Metabolic syndrome" by WHO in 1999 2. Obese diabetics have excess of 11-beta-HSD enzyme in their visceral fat. This enzyme converts inactive cortisone to active cortisol. Transgenic mice producing excess of 11-beta-hsd develop typical features of the metabolic syndrome, suggesting excess of cortisol in tissues might be responsible for the insulin resistance, core feature of T2DM 3. Dexamethasone produces dose dependent inhibition of insulin release caused by glucose, tolbutamide & other insulin releasers 4. Therefore only insulin sensitisers & insulin are likely to be effective in dexamethasone induced diabetes. Insulin sensitisers like Rosiglitazone & metformin are being evaluated for primary prevention of T2DM in high risk patients 5. They produce several adverse effects. | ||||||||||||||||||||||||||||||||||||||
| Water extract of cinnamon has insulin sensitizing activity in vitro. 6�� Methyl hydroxyl chalcone polymer has been identified as the active chemical. 7 �Clinical trial in human beings has demonstrated the hypoglycemic & hypolipidemic effects of cinnamon. 8 However no study has been done in glucocorticoid induced diabetes. Hence we undertook this study. | ||||||||||||||||||||||||||||||||||||||
| Materials & Methods: | ||||||||||||||||||||||||||||||||||||||
| Two groups of male albino rats, six in each group, weighing around two hundred grams were injected with 12mg/kg of dexamethasone i.p. for a period of six days. One group received 10ml/kg of water extract of cinnamon representing water soluble content in 5g of the powder orally & the other group received 10ml/kg of distilled water for seven days before & during dexamethasone administration. Fasting & fed blood glucose levels 1 hour after a glucose load of 2.5g/kg/i.p were recorded on the sixth day. | ||||||||||||||||||||||||||||||||||||||
| Statistical significance was measured by paired?t? test. Probability values less than 0.05 are considered significant. Results have been depicted in graphical format | ||||||||||||||||||||||||||||||||||||||
| Results: | ||||||||||||||||||||||||||||||||||||||
| Water extract of cinnamon produced 30% reduction of FBS & 25% reduction in fed glucose level, 1 hour after the glucose load. | ||||||||||||||||||||||||||||||||||||||
| Discussion & Conclusion: | ||||||||||||||||||||||||||||||||||||||
| Water extract of Cinnamon produced significant reduction in both fasting & fed blood glucose levels. In our model, only drugs with efficacy comparable to metformin & rosiglitazone are effective. In the case of cinnamon clinical trials have shown beneficial results confirming our belief that large dose dexamethasone induced diabetes in rats is suitable for screening insulin sensitizers of clinical efficacy. | ||||||||||||||||||||||||||||||||||||||
| References: | ||||||||||||||||||||||||||||||||||||||
| 1 J.I Bell, T.D.R Hockaday. Diabetes Mellitus In: D.J Weatherall, J.G.G Ledingam, D.A Warell, et al, editors. Oxford Textbook of Medicine 3rd ed.� New York: Oxford Medical Publication; 1996. P. 1448-504. | ||||||||||||||||||||||||||||||||||||||
| 2 Melvin R. Hayden and Suresh C. Tungi. Review Article: Intimal redox stress: Accelerated atherosclerosis in metabolic syndrome and type 2 diabetes mellitus Atheroscleropathy. Cardiovascular Diabetology 2002; September.P.1-27. | ||||||||||||||||||||||||||||||||||||||
| 3. Masuzaki H, Paterson J, Shinyama H, Morton NM, Mullins JJ, Seckl JR, Flier JS.� A transgenic model of visceral obesity and the metabolic syndrome. �Science.2001 Dec 7; 294(5549):2166-70 |
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| 4.C�cileLambillotte, Patrick Gilon, and Jean-Claude Henquin,�� Direct Glucocorticoid Inhibition of Insulin Secretion. J.Clin. Invest.1997;99:414-423 | ||||||||||||||||||||||||||||||||||||||
| 5.�Roopa R Sathyaprakash and Robert R Henry, �Preventing Diabetes by Treating Aspects of the Metabolic Syndrome, ��Current Diabetes Reports 2002; 2: 416-422 | ||||||||||||||||||||||||||||||||||||||
| 6.Broadhurst CL, Polansky MM, Anderson RA: Insulin-like biological activity of culinary and medicinal plant aqueous extracts in vitro. J Agric Food Chem 48:849?852, 2000 | ||||||||||||||||||||||||||||||||||||||
| 7 Jarvill-Taylor KJ, Anderson RA, Graves DJ: A hydroxychalcone derived from cinnamon functions as a mimetic for insulin in 3T3?L1 adipocytes. J Am Coll Nutr 20:327?336, 2001 | ||||||||||||||||||||||||||||||||||||||
| 8. Alam Khan,� Mahpara Safdar,� Mohammad Muzaffar Ali Khan,� Khan Nawaz Khattak,� Richard A. Anderson : Cinnamon Improves Glucose and Lipids of People With Type 2 Diabetes� Diabetes Care 26:3215-3218, 2003 | ||||||||||||||||||||||||||||||||||||||
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