Extract of lotus leaf (Nelumbo nucifera) and its active constituent catechin with insulin secretagogue activity
Journal
Journal of Agricultural and Food Chemistry
Journal Volume
59
Journal Issue
4
Pages
1087-1094
Date Issued
2011
Author(s)
Abstract
The effect of lotus leaf (Nelumbo nucifera Gaertn.) on diabetes is unclear. We hypothesized that lotus leaf can regulate insulin secretion and blood glucose levels. The in vitro and in vivo effects of lotus leaf methanolic extract (NNE) on insulin secretion and hyperglycemia were investigated. NNE increased insulin secretion from β cells (HIT-T15) and human islets. NNE enhanced the intracellular calcium levels in β cells. NNE could also enhance phosphorylation of extracellular signal-regulated protein kinases (ERK)1/2 and protein kinase C (PKC), which could be reversed by a PKC inhibitor. The in vivo studies showed that NNE possesses the ability to regulate blood glucose levels in fasted normal mice and high-fat-diet-induced diabetic mice. Furthermore, the in vitro and in vivo effects of the active constituents of NNE, quercetin, and catechin, on glucose-induced insulin secretion and blood glucose regulation were evaluated. Quercetin did not affect insulin secretion, but catechin significantly and dose-dependently enhanced insulin secretion. Orally administered catechin significantly reversed the glucose intolerance in high-fat-diet-induced diabetic mice. These findings suggest that NNE and its active constituent catechin are useful in the control of hyperglycemia in non-insulin-dependent diabetes mellitus through their action as insulin secretagogues. ? 2011 American Chemical Society.
SDGs
Other Subjects
(NNE); catechin; diabetesmellitus; Extracellular signal-regulated protein kinase; Nelumbo nucifera Gaertn; protein kinase C; Blood; Enzyme activity; Enzymes; Fatty acids; Glucose; Insulin; Nutrition; Organic compounds; Phosphorylation; Physiology; Plants (botany); Phenols; calcium; catechin; insulin; plant extract; animal; article; cell line; chemistry; drug effect; experimental diabetes mellitus; fat intake; glucose blood level; human; Institute for Cancer Research mouse; male; mouse; Nelumbo; pancreas islet; pancreas islet beta cell; plant leaf; secretion; Animals; Blood Glucose; Calcium; Catechin; Cell Line; Diabetes Mellitus, Experimental; Dietary Fats; Humans; Insulin; Insulin-Secreting Cells; Islets of Langerhans; Male; Mice; Mice, Inbred ICR; Nelumbo; Plant Extracts; Plant Leaves; Mus; Nelumbo nucifera
Type
journal article