Treatment with Rhodiola crenulata root extract ameliorates insulin resistance in fructose-fed rats by modulating sarcolemmal and intracellular fatty acid translocase/CD36 redistribution in skeletal muscle.

Ting Chen,Liang Zhou,Jianwei Wang,Ling Yao,Jian Jiang,Johji Yamahara,Yuhao Li,Weiguo Cao,Guowei Zuo,Dazhi Ke

doi:10.1186/s12906-016-1176-z

Ting Chen, Liang Zhou + Show 8 more

Open Access

https://doi.org/10.1186/s12906-016-1176-z

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Abstract

BackgroundRhodiola species have been used for asthenia, depression, fatigue, poor work performance and cardiovascular diseases, all of which may be associated with insulin resistance. To disclose the underlying mechanisms of action, the effect of Rhodiola crenulata root (RCR) on insulin resistance was investigated.MethodsMale Sprague-Dawley rats were treated with liquid fructose in their drinking water over 18 weeks. The extract of RCR was co-administered (once daily by oral gavage) during the last 5 weeks. The indexes of lipid and glucose homeostasis were determined enzymatically and/or by ELISA. Gene expression was analyzed by Real-time PCR, Western blot and/or confocal immunofluorescence.ResultsRCR extract (50 mg/kg) suppressed fructose-induced hyperinsulinemia and the increases in the homeostasis model assessment of insulin resistance index and the adipose tissue insulin resistance index in rats. Additionally, this treatment had a trend to restore the ratios of glucose to insulin and non-esterified fatty acids (NEFA) to insulin. Mechanistically, RCR suppressed fructose-induced acceleration of the clearance of plasma NEFA during oral glucose tolerance test (OGTT), and decreased triglyceride content and Oil Red O staining area in the gastrocnemius. Furthermore, RCR restored fructose-induced sarcolemmal overexpression and intracellular less distribution of fatty acid translocase/CD36 that contributes to etiology of insulin resistance by facilitating fatty acid uptake.ConclusionThese results suggest that RCR ameliorates insulin resistance in fructose-fed rats by modulating sarcolemmal and intracellular CD36 redistribution in the skeletal muscle. Our findings may provide a better understanding of the traditional use of Rhodila species.

Highlights

Rhodiola species have been used for asthenia, depression, fatigue, poor work performance and cardiovascular diseases, all of which may be associated with insulin resistance
To better understand the traditional application of Rhodila species, the present study investigated the effect of an extract of Rhodiola crenulata root (RCR) on insulin resistance and the possible involvement of CD36 in the underlying mechanisms of action in liquid fructose-fed rats
The present study clearly demonstrated that treatment with RCR extract suppressed fructose-induced hyperinsulinemia, and increases in the homeostasis model assessment of insulin resistance (HOMA-IR) index and the Adipo-IR index in rats

Summary

Introduction

Rhodiola species have been used for asthenia, depression, fatigue, poor work performance and cardiovascular diseases, all of which may be associated with insulin resistance. A large body of evidence has suggested that depression and fatigue are linked to some metabolic disorders, such as obesity, insulin resistance, diabetes and liver disease [2,3,4,5,6,7,8,9]. It has been suggested that insulin resistance is a part of the pathophysiology of affective disorders, and that improvement of insulin resistance may reduce the severity of depressive symptoms [10, 11]. These research findings suggest that amelioration of insulin resistance may result in improvement of depression and fatigue, and effective prevention or treatment of depression may reduce insulin resistance-associated health consequences

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