Hypoglycemic and hypolipidemic effects of Epigynum auritum in high fat diet and streptozotocin-induced diabetic rats

Mei-Lian Yang; Can Lu; Zhi-Feng Fan; Tian-Rui Zhao; Gui-Guang Cheng; Yu-Dan Wang; Jian-Xin Cao; Ya-Ping Liu

doi:10.1016/j.jep.2022.114986

Hypoglycemic and hypolipidemic effects of Epigynum auritum in high fat diet and streptozotocin-induced diabetic rats

J Ethnopharmacol. 2022 Apr 24:288:114986. doi: 10.1016/j.jep.2022.114986. Epub 2022 Jan 13.

Authors

Mei-Lian Yang¹, Can Lu², Zhi-Feng Fan³, Tian-Rui Zhao¹, Gui-Guang Cheng¹, Yu-Dan Wang⁴, Jian-Xin Cao⁵, Ya-Ping Liu⁶

Affiliations

¹ Faculty of Food Science and Engineering, Kunming University of Science and Technology, Kunming, 650500, People's Republic of China.
² Department of Cardiology, The First People's Hospital of Yunnan Province, The Affiliated Hospital of Kunming University of Science and Teco, People's Republic of China.
³ Faculty of Food Science and Engineering, Kunming University of Science and Technology, Kunming, 650500, People's Republic of China; Engineering Research Center of Biopolymer Functional Materials of Yunnan, Yunnan Minzu University, Kunming, 650500, People's Republic of China.
⁴ Faculty of Food Science and Engineering, Kunming University of Science and Technology, Kunming, 650500, People's Republic of China; Engineering Research Center of Biopolymer Functional Materials of Yunnan, Yunnan Minzu University, Kunming, 650500, People's Republic of China. Electronic address: sdlcwyd@163.com.
⁵ Faculty of Food Science and Engineering, Kunming University of Science and Technology, Kunming, 650500, People's Republic of China. Electronic address: jxcao321@hotmail.com.
⁶ Faculty of Food Science and Engineering, Kunming University of Science and Technology, Kunming, 650500, People's Republic of China. Electronic address: liuyaping@kust.edu.cn.

PMID: 35032587
DOI: 10.1016/j.jep.2022.114986

Abstract

Ethnopharmacological relevance: Epigynum auritum is mainly distributed in Southwest China, and has been used as a "dai" folk medicine with promising Besides, the leaves and barks of E. auritum have detoxifying, analgesic and relieving swelling effects. Previous studies evidenced that E. auritum was rich in pregnanes and their glycosides. However, the hypoglycemic and hypolipidemic effects of the extract from E. auritum (EAE) and its molecular mechanism are still not studied.

Aim of the study: The aim of this study is to investigate the hypoglycemic and hypolipidemic effects of EAE on high-fat diet and streptozocin-induced type 2 diabetic rats.

Materials and methods: The high-fat diet and streptozocin induced type 2 diabetic model was established. The diabetic rats were treated with 70% ethanol extract of E. auritum (100 and 300 mg/kg/d) or metformin (DMBG, 100 mg/kg/d) every day for 4 weeks. Fasting blood glucose was recorded weekly. The phenotypic changes were evaluated by the measurement of biochemical indexes and immunohistochemical. The expressions of signaling-related proteins were explored by western blotting.

Results: EAE could effectively regulate the metabolism of glucose and lipids in diabetic rats by increasing insulin sensitivity. In addition, EAE ameliorated the oxidative stress damage and further mitigated the liver, kidney, and pancreatic damage. Mechanism research results show that EAE treatment increased the phosphorylation of Akt, AMPK and GSK-3β, up-regulated the expression of GLUT-2, GLUT-4 and PPAR-α, and reduced PPAR-γ and FAS expressions.

Conclusion: EAE exhibited significant hypoglycemic and hypolipidemic effects in HFD/STZ-induced diabetes rats. The mechanism may be related to the effective upregulation of AMPK/Akt/GSK-3β pathway and the decreased expression of PPAR-γ and FAS. It could be a promising natural product with potential value for the development of drugs to prevent or treat type 2 diabetic.

Keywords: AMPK/Akt/GSK-3β pathway; Dyslipidemia; Epigynum auritum; Oxidative stress; Type 2 diabetic.

Publication types

Comparative Study

MeSH terms

Animals
Apocynaceae / chemistry*
Blood Glucose / drug effects
Diabetes Mellitus, Experimental / drug therapy*
Diabetes Mellitus, Type 2 / drug therapy*
Diet, High-Fat
Dose-Response Relationship, Drug
Hypoglycemic Agents / administration & dosage
Hypoglycemic Agents / isolation & purification
Hypoglycemic Agents / pharmacology
Hypolipidemic Agents / administration & dosage
Hypolipidemic Agents / isolation & purification
Hypolipidemic Agents / pharmacology
Insulin Resistance
Male
Metformin / pharmacology
Oxidative Stress / drug effects
Plant Extracts / pharmacology*
Rats
Rats, Sprague-Dawley
Streptozocin

Substances

Blood Glucose
Hypoglycemic Agents
Hypolipidemic Agents
Plant Extracts
Streptozocin
Metformin