[Effect of Psidium guajava leaf extract on alpha-glucosidase activity in small intestine of diabetic mouse].
OBJECTIVE
To investigate the inhibition effect of Psidium guajava linn (PGL), a leaf water-soluble extract, on the activities of alpha-glucosidases.


METHODS
The PGL water-soluble extract (PGL WE) was obtained by the procedure of distilled water immersion, filtration, extracted fluid concentration and dry of Psidium guajava leaf. The diabetes of Kunming mice was induced by intraperitoneal injection of Streptozotocin (STZ). The small intestinal mucosa of diabetic mice was scraped to make the homogenate for the preparation of alpha-glucosidases. In vitro, the homogenates were incubated with sucrose and maltose. The formed glucose represented the activities of alpha-glucosidases. The Lineweaver-Burk plot was applied to determine the type of alpha-glucosidase activity inhibited.


RESULTS
The water-soluble extract from PGL significantly inhibited, in the dose-dependent manner, the activities of alpha-glucosidase from small intestinal mucosa of diabetic mice. The PGL extract inhibition concentration (IC50) to sucrase or maltase was 1.0 g/L or 3.0 g/L respectively. The mixed inhibition type was showed to be the competitive and non-competitive inhibition.


CONCLUSIONS
The GPL water-soluble extract possesses the potential effect of inhibition on the alpha-glucosidase activity from the small intestinal mucosa of diabetic mouse.
Wang
Bo
B
Department of Nutrition and Food Hygiene, West China School of Public Health, Sichuan University, Chengdu 610041, China.
Liu
Heng-Chuan
HC
Hong
Jun-Rong
JR
Li
Hong-Gu
HG
Huang
Cheng-Yu
CY
D000818:Animals; D001667:Binding, Competitive; D001786:Blood Glucose / Q000378:metabolism; D003920:Diabetes Mellitus / Q000201:enzymology* / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology; D065089:Glycoside Hydrolase Inhibitors; D020128:Inhibitory Concentration 50; D007421:Intestine, Small / Q000187:drug effects* / Q000201:enzymology*; D008297:Male; D051379:Mice; D010936:Plant Extracts / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D018515:Plant Leaves / Q000737:chemistry*; D031647:Psidium / Q000737:chemistry*; D012995:Solubility; D014867:Water / Q000737:chemistry; D000520:alpha-Glucosidases / Q000378:metabolism
D001786:Blood Glucose; D004791:Enzyme Inhibitors; D065089:Glycoside Hydrolase Inhibitors; D010936:Plant Extracts; D014867:Water; D000520:alpha-Glucosidases