Gastrodia elata Blume water extracts improve insulin resistance by decreasing body fat in diet-induced obese rats: vanillin and 4-hydroxybenzaldehyde are the bioactive candidates.

Abstract

BACKGROUND:

Insulin resistance is a common symptom of metabolic diseases such as obesity, type 2 diabetes and hyperlipidemia.

AIM OF THE STUDY:

We investigated whether Gastrodia elata Blume water extract(GEB), containing phenolic compounds, had a beneficial action on insulin resistance in male Sprague-Dawley rats fed a high fat diet(HFD) and determined how this effect was produced. In addition, the bioactive candidates involved were identified.

METHODS:

Rats fed HFD were daily administered with 0.3 g GEB(GEB-L), 1 g GEB(GEB-H), or 1 g cellulose(control) per kg body weight for 8 weeks, while rats in the fourth group were fed a low fat diet(LFD). In vitro study, 4 major components of GEB were tested for their impact on fat accumulation.

RESULTS:

Rats in the control group exhibited a higher weight gain of epididymal and retroperitoneal fat pads than those fed LFD, while GEB prevented such an increment in a dose-dependent manner. GEB-H significantly decreased energy intake partly through potentiating STAT3 phosphorylation and attenuating AMPK phosphorylation in the hypothalamus. GEB-H also increased energy expenditure with the increase in fat oxidation. GEB-H increased whole body glucose disposal rates and decreased hepatic glucose output compared to the control. Among the major components of GEB, 4-hydroxybenzaldehyde and vanillin decreased triglyceride accumulation by modulating the expression of genes involved in fat metabolism in 3T3-L1 adipocytes. They increased insulin-stimulated glucose uptake to reduce insulin resistance.

CONCLUSIONS:

GEB-H, mainly as a result of the action of 4-hydroxybenzaldehyde and vanillin, reduces insulin resistance by decreasing fat accumulation in adipocytes by activating fat oxidation and potentiating leptin signaling in diet-induced obese rats.

• Authors: Sunmin Park, Da Sol Kim, Suna Kang
• Journal: European journal of nutrition (Eur J Nutr) Vol. 50 Issue 2 Pg. 107-18 (Mar 2011) ISSN: 1436-6215 [Electronic] Germany
• PMID: 20577883 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Benzaldehydes
• Dietary Fats
• Insulin
• Leptin
• Plant Extracts
• STAT3 Transcription Factor
• Stat3 protein, rat
• vanillin
• Adenylate Kinase
• 4-hydroxybenzaldehyde

Topics

• Adenylate Kinase (metabolism)
• Adipose Tissue (drug effects)
• Animals
• Benzaldehydes (pharmacology)
• Body Weight
• Cell Line
• Diet, Fat-Restricted
• Dietary Fats (administration & dosage)
• Energy Intake
• Energy Metabolism
• Gastrodia (chemistry)
• Glucose Tolerance Test
• Hypothalamus (metabolism)
• Insulin (blood)
• Insulin Resistance
• Leptin (metabolism)
• Male
• Mice
• Obesity (drug therapy)
• Plant Extracts (pharmacology)
• Rats
• Rats, Sprague-Dawley
• STAT3 Transcription Factor (metabolism)