Syzygium cumini ameliorates insulin resistance and β-cell dysfunction via modulation of PPAR, dyslipidemia, oxidative stress, and TNF-α in type 2 diabetic rats.

Abstract

Syzygium cumini (SC) is well known for its anti-diabetic potential, but the mechanism underlying its amelioration of type 2 diabetes is still elusive. Therefore, for the first time, we investigated whether SC aqueous seed extract (100, 200, or 400 mg/kg) exerts any beneficial effects on insulin resistance (IR), serum lipid profile, antioxidant status, and/or pancreatic β-cell damage in high-fat diet / streptozotocin-induced (HFD-STZ) diabetic rats. Wistar albino rats were fed with HFD (55% of calories as fat) during the experiment to induce IR and on the 10th day were injected with STZ (40 mg/kg, i.p.) to develop type 2 diabetes. Subsequently, after confirmation of hyperglycemia on the 14th day (fasting glucose level > 13.89 mM), diabetic rats were treated with SC for the next 21 days. Diabetic rats showed increased serum glucose, insulin, IR, TNF-α, dyslipidemia, and pancreatic thiobarbituric acid-reactive substances with a concomitant decrease in β-cell function and pancreatic superoxide dismutase, catalase, and glutathione peroxidase antioxidant enzyme activities. Microscopic examination of their pancreas revealed pathological changes in islets and β-cells. These alterations reverted to near-normal levels after treatment with SC at 400 mg/kg. Moreover, hepatic tissue demonstrated increased PPARγ and PPARα protein expressions. Thus, our study demonstrated the beneficial effect of SC seed extract on IR and β-cell dysfunction in HFD-STZ-induced type 2 diabetic rats.

• Authors: Ashok Kumar Sharma, Saurabh Bharti, Rajiv Kumar, Bhaskar Krishnamurthy, Jagriti Bhatia, Santosh Kumari, Dharamvir Singh Arya
• Journal: Journal of pharmacological sciences (J Pharmacol Sci) Vol. 119 Issue 3 Pg. 205-13 ( 2012) ISSN: 1347-8648 [Electronic] Japan
• PMID: 22786584 (Publication Type: Journal Article)

Chemical References

• Antioxidants
• Blood Glucose
• Hypoglycemic Agents
• Insulin
• Lipids
• Peroxisome Proliferator-Activated Receptors
• Plant Extracts
• Thiobarbituric Acid Reactive Substances
• Tumor Necrosis Factor-alpha
• Streptozocin
• Catalase
• Glutathione Peroxidase
• Superoxide Dismutase

Topics

• Animals
• Antioxidants (metabolism)
• Blood Glucose (metabolism)
• Catalase (metabolism)
• Diabetes Mellitus, Experimental (drug therapy, metabolism)
• Diabetes Mellitus, Type 2 (blood, drug therapy, metabolism)
• Dyslipidemias (drug therapy, metabolism)
• Female
• Glutathione Peroxidase (metabolism)
• Homeostasis (drug effects)
• Hyperglycemia (drug therapy, metabolism)
• Hypoglycemic Agents (pharmacology)
• Insulin (blood)
• Insulin Resistance
• Insulin-Secreting Cells (drug effects, metabolism)
• Islets of Langerhans (drug effects, metabolism)
• Lipids (blood)
• Male
• Oxidative Stress (drug effects)
• Pancreas (drug effects)
• Peroxisome Proliferator-Activated Receptors (metabolism)
• Plant Extracts (pharmacology)
• Rats
• Rats, Wistar
• Seeds (chemistry)
• Streptozocin (pharmacology)
• Superoxide Dismutase (metabolism)
• Syzygium (chemistry)
• Thiobarbituric Acid Reactive Substances (metabolism)
• Tumor Necrosis Factor-alpha (blood, metabolism)