Berberine promotes glucagon-like peptide-1 (7-36) amide secretion in streptozotocin-induced diabetic rats.
Berberine (BBR), a hypoglycemic agent, has shown beneficial metabolic effects for anti-diabetes, but its precise mechanism was unclear. Glucagon-like peptide-1 (GLP-1) is considered to be an important incretin that can decrease hyperglycemia in the gastrointestinal tract after meals. The aim of this study was to investigate whether BBR exerts its anti-diabetic effects via modulating GCG secretion. Diabetes-like rats induced by streptozotocin received BBR (120 mg/kg per day, i.g) for 5 weeks. Two hours following the last dose, the rats were anaesthetized and received 2.5 g/kg glucose by gavage. At 15-minute and 30-minute after glucose load, blood samples, pancreas, and intestines were obtained to measure insulin and GCG using ELISA kit. The number of L cells in the ileum and beta-cells in the pancreas were identified using immunohistology. The expression of proglucagon mRNA in the ileum was measured by RT-PCR. The results indicated that BBR treatment significantly increased GCG levels in plasma and intestine (P<0.05) accompanied with the increase of proglucagon mRNA expression and the number of L-cell compared with the controls (P<0.05). Furthermore, BBR increased insulin levels in plasma and pancreas as well as beta-cell number in pancreas. The data support the hypothesis that the anti-diabetic effects of BBR may partly result from enhancing GCG secretion.
Lu
Shou-Si
SS
Key Lab of Drug Metabolism and Pharmacokinetics, China Pharmaceutical University, Nanjing 210009, People's Republic of China.
Yu
Yun-Li
YL
Zhu
Hao-Jie
HJ
Liu
Xiao-Dong
XD
Liu
Li
L
Liu
Yao-Wu
YW
Wang
Ping
P
Xie
Lin
L
Wang
Guang-Ji
GJ
D000818:Animals; D000903:Antibiotics, Antineoplastic / Q000494:pharmacology; D001599:Berberine / Q000008:administration & dosage*; D003920:Diabetes Mellitus / Q000139:chemically induced / Q000188:drug therapy*; D004195:Disease Models, Animal; D015870:Gene Expression; D052216:Glucagon-Like Peptide 1 / Q000097:blood* / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D007004:Hypoglycemic Agents / Q000008:administration & dosage*; D007328:Insulin / Q000097:blood; D007413:Intestinal Mucosa / Q000378:metabolism; D010446:Peptide Fragments / Q000097:blood* / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D052336:Proglucagon; D051381:Rats; D017207:Rats, Sprague-Dawley; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013311:Streptozocin / Q000494:pharmacology
D000903:Antibiotics, Antineoplastic; D007004:Hypoglycemic Agents; D007328:Insulin; D010446:Peptide Fragments; D001599:Berberine; C055453:glucagon-like peptide 1 (7-36)amide; D052336:Proglucagon; D013311:Streptozocin; D052216:Glucagon-Like Peptide 1