title: Antihyperglycemic and antioxidative potential of Psidium guajava fruit in streptozotocin-induced diabetic rats.
abstract: Psidium guajava Linn. (family Myrtaceae; PG) is a tropical fruit with a blood-glucose-lowering effect in diabetic rats, but its mechanism of action is still unknown. We investigated the antihyperglycemic efficacy and mechanisms of action of PG in streptozotocin (STZ)-induced diabetic rats. After 4 weeks of PG supplementation (125 and 250 mg/kg), PG significantly restored the loss of body weight caused by STZ and reduced blood glucose levels in a dose-dependent manner compared with that in diabetic control rats. Mechanistically, PG protected pancreatic tissues, including islet β-cells, against lipid peroxidation and DNA strand breaks induced by STZ, and thus reduced the loss of insulin-positive β-cells and insulin secretion. Moreover, PG also markedly inhibited pancreatic nuclear factor-kappa B protein expression induced by STZ and restored the activities of antioxidant enzymes, including superoxide dismutase, catalase, and glutathione peroxidase. We conclude that PG has a significant antihyperglycemic effect, and that this effect is associated with its antioxidative activity.
authors.affiliation: Department of Health and Nutrition Biotechnology, Asia University, Taichung, Taiwan. cshuang@asia.edu.tw
authors.forename: Chin-Shiu
authors.initials: CS
authors.lastname: Huang
authors.forename: Mei-Chin
authors.initials: MC
authors.lastname: Yin
authors.forename: Lan-Chi
authors.initials: LC
authors.lastname: Chiu
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D001786:Blood Glucose / Q000032:analysis; D015153:Blotting, Western; D020552:Comet Assay; D003921:Diabetes Mellitus, Experimental / Q000378:metabolism*; D007004:Hypoglycemic Agents / Q000494:pharmacology*; D007150:Immunohistochemistry; D015227:Lipid Peroxidation; D008297:Male; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D031647:Psidium / Q000737:chemistry*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013311:Streptozocin
chemical_list: D000975:Antioxidants; D001786:Blood Glucose; D007004:Hypoglycemic Agents; D010936:Plant Extracts; D013311:Streptozocin