Anti-obesity effect and signaling mechanism of Chaenomeles sinensis extracts

다국어 초록 (Multilingual Abstract)

ABSTRACT

Anti-obesity effect and signaling mechanism of Chaenomeles sinensis extracts

Kim, Da Hye
Dept. of Pharmacy
College of Pharmacy
Graduate School of
Woosuk University

Obesity is one of the most serious health problem because it induced numerous metabolic syndrome and increases the incidence of various disease, including diabetes, hypertension, dyslipidemia, atherosclerosis, and cancer. In 3T3-L1 adipocytes, increases in reactive oxygens species (ROS) occur with lipid accumulation. NADPH oxidase (NOX), producing superoxide anion, may contribute to the development of obesity-associated insulin resistance and type 2 diabetes. In this study, our purpose is to investigate Chaenomeles sinensis Koehne extract (CSE) whether reduced the development of obesity through inhibition of adipogenesis. CSE remarkably reduced intracellular ROS increase and mechanism of NOX1, NOX4, Rac1 protein expression, and phosphorylation of p47phox and p67phox. CSE also decreased triglyceride content and inhibited the expression of adipogenic transcription factors including peroxisome proliferator-activated receptor (PPAR)g, CCAT/enhancer binding protein (C/EBP)a and sterol regulatory element-binding protein (SREBP-1). CSE highly increased antioxidant activity in a dose-dependent manner.
We investigated the effect of CSE on weight gain induced by High fat diet (HD). The oral treatment of CSE (500 mg/kg, body weight) in diet-induced obese (DIO) mice showed decrease triglyceride and adipocyte size. Therefore, these results indicate that the effect of CSE on anti-obesity effect, adipocyte differentiation and reducing triglyceride contents as well as adipocyte size in obese mice, may be associated with inhibit NOX-induced ROS production and adipose transcription factors.

Key words : Chaenomeles sinensis Koehne, 3T3-L1, Obesity, NADPH oxidase, reactive oxygen species

목차 (Table of Contents)

• List of Figures ⅷ
• List of Abbreviations ⅸ
• Abstract 1
• Ⅰ. INTRODUCTION 3
• Ⅱ. MATERIALS AND METHODS
• 1. Chemicals and Materials 6
• 2. Preparation of the C. sinensis extract (CSE) 6
• 3. Solvent fractionation and isolation 7
• 4. Cell culture and adipocyte differentiation 8
• 5. Cell viability 8
• 6. Oil red O staining 9
• 7. Measurement of triglyceride content 9
• 8. Antioxidant effect assay 10
• 8-1. DPPH radical scavenging activity 10
• 8-2. ABTS radical scavenging activity 10
• 8-3. Superoxide dismutase (SOD) assay 11
• 8-4. Measurement of reactive oxygen species (ROS) 11
• 9. Animals 12
• 10. Western blot analyis 13
• 11. Histological analysis 14
• 12. RNA extraction and reverse transcriptase-polymerase chain reaction (RT-PCR) 14
• 13. Statistical analysis 16
• Ⅲ. RESULTS 17
• 1. C. sinensis water extracts (CSE) prevents adipogenesis in 3T3-L1 adipocytes 17
• 2. Cytotoxicity of CSE in 3T3-L1 cells 18
• 3. Antioxidant activities of CSE 18
• 3-1. DPPH radical scavenging activity 18
• 3-2. ABTS radical scavenging activity 18
• 3-3. Superoxide dismutase (SOD) activity 18
• 4. CSE effect on ROS generation in 3T3-L1 19
• 5. CSE attenuates NOX-induced ROS production 19
• 6. Effect of CSE on the expression of adipogenic-specific genes and proteins 20
• 7. CSE reduced body weight gain and total fat mass in mice with HFD-induced obesity 21
• 8. CSE suppresses lipid droplet accumulation in the liver and visceral adipose tissue 22
• 9. Anti-adipogenic effect of partitioned fractions from CSE in 3T3-L1 cells 22
• 10. Analysis of phenolic compounds in CSE and their effect on lipid accumulation in 3T3-L1 cells 24
• Ⅳ. DISCUSSION 26
• Ⅴ. CONCLUSION 29
• References 30
• Korean abstract 41