Hypoglycemic effects of aqueous persimmon leaf extract in a murine model of diabetes

Mol Med Rep. 2015 Aug;12(2):2547-54. doi: 10.3892/mmr.2015.3766. Epub 2015 May 8.

Abstract

Previously, powdered persimmon leaves have been reported to have glucose- and lipid-lowering effects in diabetic (db/db) mice. As persimmon leaf is commonly consumed as tea, an aqueous extract of persimmon leaves (PLE) was prepared and its anti-diabetic efficacy was investigated. In the present study, PLE was tested for its inhibitory activity on α-glucosidase in vitro. An oral maltose tolerance test was performed in diabetic mice. Next, the acute effect of PLE was examined in streptozotocin-induced diabetic mice. Last, the long-term effect of PLE supplementation was assessed in db/db after eight weeks. An oral glucose tolerance test, biochemical parameters, as well as histological analyses of liver and pancreas were evaluated at the end of the study. PLE inhibited α-glucosidase activity and increased antioxidant capacity. Streptozotocin-induced diabetic mice pre-treated with PLE displayed hypoglycemic activity. Daily oral supplementation with PLE for eight weeks reduced body weight gain without affecting food intake, enhanced the glucose tolerance during the oral glucose tolerance test (OGTT), improved blood lipid parameters, suppressed fat accumulation in the liver and maintained islet structure in db/db mice. Further mechanistic study showed that PLE protected pancreatic islets from glucotoxicity. In conclusion, the results of the present study indicated that PLE exhibits considerable anti-diabetic effects through α-glucosidase inhibition and through the maintenance of functional β-cells. These results provided a rationale for the use of persimmon leaf tea for the maintenance of normal blood glucose levels in diabetic patients.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antioxidants / isolation & purification
  • Antioxidants / pharmacology*
  • Biphenyl Compounds / antagonists & inhibitors
  • Blood Glucose / drug effects
  • Body Weight / drug effects
  • Diabetes Mellitus, Experimental / chemically induced
  • Diabetes Mellitus, Experimental / drug therapy*
  • Diabetes Mellitus, Experimental / metabolism
  • Diabetes Mellitus, Experimental / pathology
  • Diospyros / chemistry*
  • Eating
  • Glucose Tolerance Test
  • Glycoside Hydrolase Inhibitors / isolation & purification
  • Glycoside Hydrolase Inhibitors / pharmacology*
  • Humans
  • Hypoglycemic Agents / isolation & purification
  • Hypoglycemic Agents / pharmacology*
  • Insulin / agonists
  • Insulin / biosynthesis
  • Islets of Langerhans / drug effects
  • Islets of Langerhans / metabolism
  • Lipogenesis / drug effects
  • Liver / drug effects
  • Liver / metabolism
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Phytotherapy / methods*
  • Picrates / antagonists & inhibitors
  • Plant Extracts / chemistry
  • Plant Leaves / chemistry
  • Streptozocin
  • alpha-Glucosidases / metabolism

Substances

  • Antioxidants
  • Biphenyl Compounds
  • Blood Glucose
  • Glycoside Hydrolase Inhibitors
  • Hypoglycemic Agents
  • Insulin
  • Picrates
  • Plant Extracts
  • Streptozocin
  • 1,1-diphenyl-2-picrylhydrazyl
  • alpha-Glucosidases