Sutherlandia frutescens limits the development of insulin resistance by decreasing plasma free fatty acid levels

Intake of high caloric food induces raised plasma free fatty acids, culminating in insulin resistance (IR) and Diabetes mellitus type 2 (DMT2). The present study has shown for the first time that Sutherlandia frutescens reduces plasma free fatty acid levels in rats fed a high fat diet, thereby preventing the development of insulin resistance. A commercially available S. frutescens extract was administered to rats to examine its effects on the progression of high fat diet induced IR. In comparison to rats fed high fat diet only (positive control for IR), levels of plasma free fatty acids (FFA) were significantly reduced after one week (p < 0.025). Twelve weeks of treatment with S. frutescens reduced the level of plasma free fatty acids below that of rats fed a normal diet (negative control) (p < 0.025). QUICKI and HOMA‐IR index confirmed that S. frutescens treated rats did not develop IR when fed a high fat diet for twelve weeks. In addition to preventing IR and reducing plasma FFA, chronic medication over twelve weeks decreased total cholesterol levels and the LDL/HDL ratio. We propose that S. frutescens is an effective medicinal remedy to prevent elevated plasma free fatty acids and IR, and therefore DMT2. Copyright © 2009 John Wiley & Sons, Ltd.     

The Beneficial Effect of Anthocyanidin‐Rich Vitis vinifera L. Grape Skin Extract on Metabolic Changes Induced by High‐Fat Diet in Mice Involves Antiinflammatory and Antioxidant Actions

We hypothesized that a polyphenol‐rich extract from Vitis vinifera L. grape skin (GSE) may exert beneficial effects on obesity and related metabolic disorders induced by a high‐fat diet (HFD). C57/BL6 mice were fed a standard diet (10% fat, control, and GSE groups) or an HFD (60% fat, high fat (HF), and HF + GSE) with or without GSE (200 mg/kg/day) for 12 weeks. GSE prevented weight gain; dyslipidemia; insulin resistance; the alterations in plasma levels of leptin, adiponectin, and resistin; and the deregulation of leptin and adiponectin expression in adipose tissue. These beneficial effects of GSE may be related to a positive modulation of insulin signaling proteins (IR, pIRS, PI3K, pAKT), pAMPK/AMPK ratio, and GLUT4 expression in muscle and adipose tissue. In addition, GSE prevented the oxidative damage, evidenced by the restoration of antioxidant activity and decrease of malondialdehyde and carbonyl levels in muscle and adipose tissue. Finally, GSE showed an anti‐inflammatory action, evidenced by the reduced plasma and adipose tissue inflammatory markers (TNF‐α, IL‐6). Our results suggest that GSE prevented the obesity and related metabolic disorders in HF‐fed mice by regulating insulin sensitivity and GLUT4 expression as well as by preventing the oxidative stress and inflammation in skeletal muscle and adipose tissue. Copyright © 2017 John Wiley & Sons, Ltd.     

Upregulation of PPARγ by Aegle marmelos ameliorates insulin resistance and β-cell dysfunction in high fat diet fed-streptozotocin induced type 2 diabetic rats

The global epidemic of type 2 diabetes demands the rapid evaluation of new and accessible interventions. This study investigated whether Aegle marmelos fruit aqueous extract (AMF; 250, 500 and 1000 mg/kg) improves insulin resistance, dyslipidemia and β‐cell dysfunction in high fat diet fed‐streptozotocin (HFD‐STZ)‐induced diabetic rats by modulating peroxisome proliferator‐activated receptor‐γ (PPARγ) expression. The serum levels of glucose, insulin, homeostasis model assessment of insulin resistance (HOMA‐IR), homeostasis model assessment of β‐cell function (HOMA‐B), lipid profile, TNF‐α and IL‐6 were evaluated. Further, the TBARS level and SOD activity in pancreatic tissue and PPARγ protein expression in liver were assessed. In addition, histopathological and ultrastructural studies were performed to validate the effect of AMF on β‐cells. The HFD‐STZ treated rats showed a significant increase in the serum levels of glucose, insulin, HOMA‐IR, TNF‐α, IL‐6, dyslipidemia with a concomitant decrease in HOMA‐B and PPARγ expression. Treatment with AMF for 21 days in diabetic rats positively modulated the altered parameters in a dose‐dependent manner. Furthermore, AMF prevented inflammatory changes and β‐cell damage along with a reduction in mitochondrial and endoplasmic reticulum swelling. These findings suggest that the protective effect of AMF in type 2 diabetic rats is due to the preservation of β‐cell function and insulin‐sensitivity through increased PPARγ expression. Copyright © 2011 John Wiley & Sons, Ltd.     

Prenylated flavonoid‐standardized extract from seeds of Psoralea corylifolia L. activated fat browning in high‐fat diet–induced obese mice

We investigated the effects of the prenylated flavonoid‐standardized extract (PFE) from the seeds of Psoralea corylifolia L. on countering obesity, which increases energy expenditure and stimulates thermogenesis in subcutaneous white adipose tissue (sWAT) and brown adipose tissue (BAT). For 12 weeks, C57BL/6 mice were fed a controlled high‐fat diet (HFD) or HFDs with 0.2% or 0.5% w/w PFE. In vitro, the differentiation of 3 T3‐L1 cells was used to elicit thermogenesis in the presence of PFE. PFE obviously reduced body weight and fat mass in a dose‐dependent manner, increased energy expenditure, improved insulin sensitivity, and prevented hepatic steatosis by increasing lipid oxidation and secretion in HFD‐fed mice. Moreover, PFE induced clear browning in sWAT, significantly increased phosphorylation of AMPKα1/2 and p38, increased BAT activity and the differentiation of 3 T3‐L1 by increasing the expression of uncoupling protein 1 and other thermogenic genes. Our study showed that PFE prevented obesity by increasing browning and activating thermogenic genes in sWAT and BAT, improving glucose homeostasis, and protecting hepatic steatosis.     

Umbelliferone Improves an Impaired Glucose and Lipid Metabolism in High‐Fat Diet/Streptozotocin‐Induced Type 2 Diabetic Rats

Umbelliferone (UMB) is a natural product that has several pharmacological effects including antihyperglycemic activity in diabetic rats. Thus, the objective of this study was to investigate the effect of UMB on insulin resistance and on the regulation of glucose and lipid metabolism in type 2 diabetic rats. Type 2 diabetes was induced in rats by feeding a high‐fat diet (45 kcal% fat) and a single dose of streptozotocin injection. After 8 weeks of treatment, UMB significantly reduced the elevated blood glucose levels and insulin resistance and increased the liver glycogen and serum adiponectin. Moreover, the serum lipid and the storages of triglyceride and non‐esterified fatty acid in liver tissue were reduced. From histological examination, the lipid droplets in liver tissue were clearly decreased, and the fat cell size in the fat tissue was smaller in diabetic rats treated with UMB. Interestingly, UMB increased fat cell adiponectin, plasma membrane glucose transporter 4 (GLUT4) and peroxisome proliferator‐activated receptor gamma (PPARγ), and liver PPARα protein expressions. Our findings demonstrate that UMB improves glucose and lipid metabolism in type 2 diabetes by stimulating the insulin secretion and the related mechanisms via stimulating expression of adiponectin, GLUT4, PPARγ, and PPARα‐protein expressions. Copyright © 2015 John Wiley & Sons, Ltd.     

Korean red ginseng (Panax ginseng) improves insulin sensitivity in high fat fed Sprague-Dawley rats

Many studies have documented that ginseng has antidiabetic and antiobesity effects, but the mechanism of the effects has not been elucidated. The aim of this study was to determine the effect of Korean red ginseng (KRG, Panax ginseng) and investigate the mechanism of antidiabetic and antiobesity effects in obese insulin resistant animal models. Sprague‐Dawley (SD) rats were divided into three groups: a control group (group I) fed a normal diet, another group (group II) fed only high fat diet (HFD) and a third group (group III) fed HFD with KRG (200 mg/kg, oral) for 18 weeks. The body weight, food intake, adipose tissues, liver, kidney, pancreas, adiponectin, and leptin were measured. Blood glucose, insulin tolerance test, and hyperinsulinemic euglycemic clamp test were investigated. A significant weight reduction, especially fat mass reduction, was observed in the KRG treated group. Increased insulin sensitivity was found in the KRG treated group. We observed increased insulin signalling, increased phosphorylation of IR, IRS‐1, Akt, and membranous GLUT4 in muscle by Western blotting assay. In conclusion, KRG may have antidiabetic and antiobesity effects due to partly increased insulin sensitivity by increased adipokine and partly enhanced insulin signalling. Copyright © 2011 John Wiley & Sons, Ltd.     

苦瓜乙醇提取物对肥胖大鼠糖代谢和内脏脂肪的影响

目的 研究苦瓜乙醇提取物对喂饲高脂饲料所致肥胖大鼠糖代谢和内脏脂肪量的影响.方法 高脂饲料饲养制备肥胖大鼠模型.肥胖大鼠随机分为模型组,苦瓜乙醇提取物低、中、高剂量(9、18、36 g/kg)组,左旋肉碱(600 mg/kg)阳性对照组,另设对照组(正常饲料饲养)和苦瓜乙醇提取物36 g/kg给药组.各组大鼠每天ig相应药物或等体积0.5％羧甲基纤维素钠溶液,每天记录摄食量,每周记录体质量.给药第6周进行糖耐量实验:给药7周后所有动物禁食18h,麻醉后腹主动脉采血,检测血清葡萄糖和胰岛素水平;分离附睾、肾周和肠系膜脂肪并称质量,附睾脂肪组织随后进行HE染色检测脂肪细胞病变.结果 苦瓜乙醇提取物36 g/kg能够明显降低肥胖大鼠体质量,抑制大鼠食物利用率,减少附睾、肾周和肠系膜白色脂肪量,降低空腹血糖浓度,抑制附睾脂肪细胞肥大;苦瓜乙醇提取物18 g/kg也明显降低肥胖大鼠附睾脂肪质量.但苦瓜乙醇提取物对肥胖大鼠的糖耐量和胰岛素抵抗指数无明显影响.结论 苦瓜乙醇提取物通过抑制肥胖大鼠内脏脂肪聚积和附睾脂肪细胞肥大以及降低空腹血糖浓度发挥减肥和抗糖尿病作用.     

黄金胶囊改善糖尿病大鼠胰岛素抵抗与PI-3K,GLUT4蛋白的表达

目的:研究黄金胶囊对糖尿病(DM)大鼠磷脂酰肌醇3激酶(PI-3K),葡萄糖转运因子4(GLUT4)在肝脏及骨骼肌组织中的蛋白表达,并探讨其改善大鼠血糖的可能机制。方法:SPF级雄性Wistar大鼠65只,血糖在4.77~7.77 mmol·L~(-1)的大鼠入选,入选大鼠60只,正常组12只外,其余大鼠采用高脂饲料喂养联合小剂量链脲佐菌素ip的方法,建立DM大鼠模型。将造模成功大鼠随机分为黄金胶囊组(2.025 g·kg~(-1)),罗格列酮组(0.36 mg·kg~(-1)),模型组,继续高脂饲料喂养,并予以相应药物ig治疗10周,其中模型组与正常组均予以生理盐水ig,观察大鼠一般状态,体重及摄食量,干预10周后,予10%水合氯醛麻醉大鼠,检测大鼠空腹血糖(FBG),空腹胰岛素(FINS)及胰岛素敏感指数(ISI)。采用苏木素-伊红(HE)检测各组大鼠肝脏、骨骼肌组织的病理改变及免疫组化检测PI-3K和GLUT4蛋白的表达。结果:与正常组比较,模型组DM大鼠FBG,FINS水平明显升高,ISI水平明显降低,肝脏及骨骼肌组织中PI-3K,GLUT4蛋白表达明显降低(P0.05),病理学检测发现大鼠肝脏、骨骼肌组织的病变较为明显;与模型组比较,药物干预后,黄金胶囊组与罗格列酮组均可降低DM大鼠的FBG,FINS水平,提高ISI水平,明显升高肝脏及骨骼肌组织中PI-3K,GLUT4蛋白表达(P0.05),大鼠肝脏、骨骼肌组织的病变明显改善。结论:黄金胶囊提高胰岛素敏感性的作用,与激活肝脏及骨骼肌组织胰岛素信号传导通路中PI-3K和GLUT4的蛋白表达有关。     

两色金鸡菊有效成分抑制体内外的代谢紊乱

目的:为了探讨两色金鸡菊乙酸乙酯提取物（EAEC）对高糖高脂引起诱导的大鼠胰岛素抵抗的影响。 方法：采用高糖高脂饲养SD雄性大鼠并灌胃给与EAEC 8周。给药结束后,采取血液测定血糖、胰岛素、血脂等指标,收集肝脏组织进行HE染色观察病理变化。细胞实验中,利用高糖处理HepG2细胞制备胰岛素抵抗模型,使用两色金鸡菊有效成分马里苷处理细胞,观察细胞糖摄取、代谢组学等。 结果：高糖高脂明显导致大鼠血糖、胰岛素、血清TC,TG,LDL-C水平显著升高,而给与EAEC则明显改善血糖代谢和血脂代谢。高糖处理的HepG2细胞显著降低肝糖原的合成,增加PEPCK,G6Pase和三羧酸循环有关的酶的蛋白水平,导致HepG2的细胞代谢紊乱,而马里苷则明显改善高糖诱导的细胞代谢紊乱。 结论：EAEC明显改善大鼠胰岛素抵抗,而马里苷能改善HepG2细胞代谢紊乱。     

Regulation of obesity and lipid disorders by extracts from Angelica acutiloba root in high-fat diet-induced obese rats

The aim of this study was to investigate the antiobesity and antihyperlipidemic effects of Angelica acutiloba root (Japanese Dong Quai). High‐fat diet (HFD)‐induced obese rats were treated orally with the polyphenolic‐rich extract of Angelica acutiloba root (AARE) once daily for 8 weeks. The AARE (300 mg/kg per day) supplementation significantly lowered body weight gain, visceral fat‐pad weights and plasma lipid levels, as well as the coronary artery risk index and the atherogenic index of HFD‐fed rats. The AARE caused dose related reductions in the hepatic triglyceride and cholesterol contents, as well as lowered hepatic lipid droplet accumulation and epididymal adipocyte size in the HFD‐fed rats. The AARE reversed the HFD‐induced down‐regulation of the hepatic peroxisome proliferator activated receptor‐α (PPARα). The HFD‐induced decreases of the hepatic protein level of acyl‐CoA oxidase (ACO), and the cytochrome P450 isoform 4A1 (CYP4A1) was up‐regulated by AARE. The elevated expressions of hepatic sterol regulatory element binding proteins (SREBPs) of HFD‐fed rats were lowered by AARE. These results suggest that AARE attenuated visceral fat accumulation and improved hyperlipidemia in HFD‐induced obesity by increasing lipid metabolism through the down‐regulation of SREBPs and enhanced the expression of ACO and CYP4A1 in the liver, which was likely mediated by up‐regulation of the expression of hepatic PPARα. Copyright © 2011 John Wiley & Sons, Ltd.     

三七皂苷Rbl改善2型糖尿病大鼠胰岛素抵抗的作用研究

目的：构建2型糖尿病大鼠模型,探讨三七皂苷Rbl在2型糖尿病大鼠胰岛素抵抗中的作用及其机制。方法：高脂、高胆固醇灌胃＋腹腔注射链脲佐菌素构建2型糖尿病大鼠模型,同时给予三七皂苷Rbl治疗,检测血清糖化血清蛋白（FMN）、甘油三酯（TG）、总胆固醇（TCHOL）、超敏c反应蛋白（CRP）、血糖（FGLU）、胰岛素（JNS）、c肽（c-P）的含量和丙二醛（MDA）、谷胱甘肽（GSH）、谷胱甘肽还原酶（GR）的含量。结果：模型组FMN、TG、TCHOL、CRP、C-P、INS和IRI明显高于对照组（P〈0．05）;模型组的T-SOD、GSH和GR的含量明显低于对照组（P〈0．05）;而MDA明显高于对照组（P〈0．05）。经三七皂苷Rbl治疗后,明显改善模型大鼠高脂血症和胰岛素抵抗,提高模型大鼠内源性巯醇抗氧化物酶的含量和减少肝组织的脂质过氧化。结论：三七皂苷Rbl能通过调控肝组织内源性巯醇抗氧化物（酶）的含量,改善2型糖尿病中的IR。     

黄连解毒汤对胰岛素抵抗大鼠脂肪组织胰岛素受体及其底物信号转导的影响

目的观察黄连解毒汤对胰岛素抵抗大鼠脂肪组织中胰岛素受体（InsR）酪氨酸磷酸化和胰岛素受体底物1（IRS-1）表达及其酪氨酸磷酸化水平的影响,探讨其改善胰岛素抵抗的分子机制。方法采用小剂量链脲佐菌素尾静脉注射加高糖高脂饲料喂养方法建立Wistar大鼠胰岛素抵抗模型,以黄连解毒汤干预治疗10周,检测血糖和血清胰岛素,用免疫沉淀和Westernblot方法检测黄连解毒汤治疗后胰岛素抵抗大鼠附睾脂肪组织内InsR酪氨酸磷酸化和IRS-1蛋白表达水平及酪氨酸磷酸化水平。结果黄连解毒汤治疗胰岛素抵抗大鼠后,脂肪组织内IRS-1表达较模型组增加,InsR和IRS-1酪氨酸磷酸化水平较模型组显著增加。结论黄连解毒汤促进胰岛素抵抗大鼠脂肪组织InsR和IRS-1酪氨酸磷酸化水平的表达,这可能是其降血糖并改善组织胰岛素敏感性的机制之一。     

Ficus carica Leaf Extract Modulates the Lipid Profile of Rats Fed with a High‐Fat Diet through an Increase of HDL‐C

Ficus carica has been traditionally used for the treatment of several metabolic syndrome‐related health problems. It was the objective of this study to investigate the preventive effects of a Ficus carica (FC) leaf extract on hyperlipidemia in high fat diet (HFD)‐induced obese male rats. Male Sprague–Dawley rats (180 – 200 g) were fed with a regular diet, HFD or a HFD + oral treatment of either 50 mg/kg or 100 mg/kg of FC or 30 mg/kg pioglitazone for six weeks. A range of parameters was evaluated including body weight development, plasma levels of total cholesterol, triglycerides (TG), low‐density‐lipoprotein cholesterol, high‐density lipoprotein cholesterol (HDL‐C), adiponectin, leptin, glucose, insulin, interleukin‐6 (IL‐6), atherogenic index (AI) and the coronary risk index (CRI). FC significantly lowered TG and IL‐6 levels and elevated HDL cholesterol (p < 0.05). The effects of FC on lipid parameters were more pronounced than those of the positive control pioglitazone. FC significantly lowered AI and CRI (p < 0.01) while it had no effect on adiponectin and leptin levels. Our results demonstrate that preventive treatment with FC significantly improved the lipid profile and decreased adipogenic risk factors in HFD rats most likely mediated through an increase in HDL‐C levels. Copyright © 2013 John Wiley & Sons, Ltd.     

Anti-diabetic activity and potential mechanism of total flavonoids of Selaginella tamariscina (Beauv.) Spring in rats induced by high fat diet and low dose STZ

Aim of the study

To evaluate the anti-diabetic effects of the total flavonoids of Selaginella tamariscina (Beauv.) Spring (TFST), and to explore the pertinent mechanism.

Materials and methods

High fat diet and STZ (35 mg/kg) induced diabetic rats were administered with TFST at graded oral doses (100, 200 and 400 mg/kg/day, ig.) for 8 weeks. A range of parameters, including blood glucose and lipid, serum insulin and glucagon, glucose tolerance, were tested to evaluate its anti-diabetic effects. The determination of protein expression of peroxisome proliferator activated receptor γ (PPAR-γ) in adipose tissue and insulin receptor substrate 1 (IRS-1) in hepatic and skeletal muscle tissues was used to study the mechanism of TFST. Moreover, the preliminary study of TFST on the antioxidant activity was performed.

Results

The TFST possessed anti-diabetic activities as shown by the decreased serum levels of fast blood glucose (FBG), glycosylated hemoglobulin A1C (HbA1c), triglyceride (TG), total cholesterol (TC), free fatty acid (FFA), low density lipoprotein-cholesterol (LDL-C) and glucagon, as well as increased serum levels of high density lipoprotein-cholesterol (HDL-C), insulin and C-peptide. TFST also improved the oral glucose tolerance test (OGTT) to a certain degree. Furthermore, TFST increased the protein expression of PPAR-γ in adipose tissue, and increased the protein expressions of IRS-1 in hepatic and skeletal muscle tissues. These benefits were associated with increased superoxide dismutase (SOD) and decreased malondialdehyde (MDA) in serum.

Conclusions

TFST exert beneficial effects on hyperglycosemia and hyperlipoidemia in diabetic rats possibly through regulating the levers of PPAR-γ in adipose tissue and IRS-1 in hepatic and skeletal muscle tissues.     

Aurantio‐obtusin improves obesity and insulin resistance induced by high‐fat diet in obese mice

Aurantio‐obtusin (AUR) is the main bioactive compound among the anthraquinones, from Cassia seed extract. This study was conducted to identify whether AUR could improve obesity and insulin resistance, induced by a high‐fat diet in obese mice. Mice were fed a high‐fat diet for 6 weeks and were then assigned to the high‐fat diet (HFD) control group, the AUR 5 mg/kg group, or the AUR 10 mg/kg group. AUR improves glucose by activating the expression of PI3K, Akt and GLUT4, GLUT2. AUR altered the expression levels of several lipid metabolism‐related and adipokine genes. AUR decreased the mRNA expression of PPAR‐γ, FAS and increased the mRNA expression of PPAR‐α in liver. AUR lowered SREBP‐1c, FAS, SCD‐1, inflammatory cytokines, and increased the expression of PPAR‐γ, PPAR‐α, CPT‐1, and adiponectin in white adipose tissue (WAT). AUR docking with the insulin receptor showed that the residues of the insulin receptor, ectodomain, were the same as those around the emodin. The effect of AUR may be elicited by regulating the activity of the insulin signaling pathway, expression of lipid metabolism‐related genes, and expression of inflammatory cytokine markers to improve adiposity, insulin resistance, and dyslipidemia.     

Triterpenoids‐Enriched Extract from the Aerial Parts of Salvia miltiorrhiza Regulates Macrophage Polarization and Ameliorates Insulin Resistance in High‐Fat Fed Mice

Adipose tissue inflammation and macrophage polarization are tightly associated with the development of obesity‐associated insulin resistance. Our previous studies have demonstrated the triterpenoids‐enriched extract from the aerial parts of Salvia miltiorrhiza (TTE) could significantly improve atherosclerosis in LDLR^?/? mice. However, its molecular mechanisms of TTE ameliorating insulin resistance remain unclear. In the present study, obesity model with insulin resistance induced by feeding high‐fat diet (HFD) was established. Dietary TTE attenuated hyperlipidemia, improved glucose intolerance in mice and mediated the activation of IRS‐1/PI3K/Akt insulin signaling pathway. Meanwhile, dietary TTE also attenuated macrophage infiltrations into adipose tissue and modified the phenotype ratio of M1/M2 macrophages. Furthermore, our results showed that TTE regulated the polarization of macrophages partly via adenosine monophosphate‐activated kinase (AMPK). Taken together, these findings suggested that TTE has a potential clinical utility in improving insulin resistance. Its mechanisms might be contributed to its beneficial effects on macrophage polarization via AMPK. Copyright © 2016 John Wiley & Sons, Ltd.     

The Anti‐Obesity Effects of the Dietary Combination of Fermented Red Ginseng with Levan in High Fat Diet Mouse Model

In this study, to evaluate the anti‐obesity effects of fermented red ginseng (FG), levan (L), and their combination (FGL), we investigated their effects on the weights of body, liver and white adipose tissue, lipid profiles, and biomarkers for insulin resistance in high fat diet (HFD)‐induced obese C57BL/6J male mice. Furthermore, the levels of leptin in the serum were measured. FG (150 mg/kg/d), L (100 mg/kg/d), and FGL (150 mg/kg/d of FG plus 100 mg/kg/d of L) were administered orally to mice daily for 11 weeks. After 11 weeks feeding, FGL showed significantly lower body weight and fat mass with decreasing food efficiency ratio than the HFD control mice. In addition, the FGL group was significantly lower in the levels of total cholesterol and fasting blood glucose and score of the homeostatic model assessment of insulin resistance. Furthermore, FGL decreased serum leptin levels compared to the HFD control group. Taken together, FGL showed a significant anti‐obesity effect in HFD‐induced obese mice and prevent insulin and leptin resistance. FGL may be potentially useful for the prevention of obesity. Copyright © 2013 John Wiley & Sons, Ltd.     

Effects of Atractylodes macrocephala Koidzumi rhizome on 3T3-L1 adipogenesis and an animal model of obesity

Ethnopharmacological relevance: Atractylodes macrocephala Koidzumi (AMK) is an herbal medicine traditionally used for treatment of abdominal pain, gastrointestinal disease, obesity, and related complications.Aim of the study: We investigated the effects and molecular mechanism of AMK rhizome water extract on 3T3-L1 adipogenesis and an animal model of obesity.

Materials and methods

To study the effect of AMK on adipogenesis in vitro, differentiating 3T3-L1 cells were treated every two days with AMK at various concentrations (1-25 μg/ml) for eight days. Oil Red O staining was performed to determine the lipid accumulation in 3T3-L1 cells. To elucidate the inhibitory mechanism of AMK on adipogenesis, phosphorylation levels of Akt and expression of perilipin, were analyzed by Western blotting. AMK was administered orally to high fat diet (HFD)-induced obese rats to confirm its effect in vivo.

Results

AMK inhibited 3T3-L1 adipocyte differentiation in a dose-dependent manner without cellular toxicity. Phospho-Akt expression was highly decreased by AMK treatment, whereas there was no significant change in perilipin expression. AMK administration significantly reduced the body weight of rats fed a HFD. Plasma triglyceride levels were significantly lower in the AMK-treated HFD group than those in the HFD control group or normal diet (ND) group, although serum total, HDL- and LDL-cholesterol levels did not differ between the groups.

Conclusion

These results demonstrate an inhibitory effect of AMK on adipogenesis through reduction of an adipogenic factor, phospho-Akt. AMK had a beneficial effect, reducing body weight gain in a HFD-induced animal model of obesity.