The Korean traditional medicine gyeongshingangjeehwan inhibits adipocyte hypertrophy and visceral adipose tissue accumulation by activating PPARalpha actions in rat white adipose tissues

Ascorbic acid inhibits visceral obesity and nonalcoholic fatty liver disease by activating peroxisome proliferator-activated receptor α in high-fat-diet-fed C57BL/6J mice

BACKGROUND/OBJECTIVES

Ascorbic acid is a known cofactor in the biosynthesis of carnitine, a molecule that has an obligatory role in fatty acid oxidation. Our previous studies have demonstrated that obesity is regulated effectively through peroxisome proliferator-activated receptor α (PPARα)-mediated fatty acid β-oxidation. Thus, this study aimed to determine whether ascorbic acid can inhibit obesity and nonalcoholic fatty liver disease (NAFLD) in part through the actions of PPARα.

DESIGN

After C57BL/6J mice received a low-fat diet (LFD, 10% kcal fat), a high-fat diet (HFD, 45% kcal fat), or the same HFD supplemented with ascorbic acid (1% w/w) (HFD-AA) for 15 weeks, variables and determinants of visceral obesity and NAFLD were examined using metabolic measurements, histology, and gene expression.

RESULTS

Compared to HFD-fed obese mice, administration of HFD-AA to obese mice reduced body weight gain, visceral adipose tissue mass, and visceral adipocyte size without affecting food consumption profiles. Concomitantly, circulating ascorbic acid concentrations were significantly higher in HFD-AA mice than in HFD mice. Ascorbic acid supplementation increased the mRNA levels of PPARα and its target enzymes involved in fatty acid β-oxidation in visceral adipose tissues. Consistent with the effects of ascorbic acid on visceral obesity, ascorbic acid not only inhibited hepatic steatosis but also increased the mRNA levels of PPARα-dependent fatty acid β-oxidation genes in livers. Similarly, hepatic inflammation, fibrosis, and apoptosis were also decreased during ascorbic acid-induced inhibition of visceral obesity. In addition, serum levels of alanine aminotransferase, aspartate aminotransferase, total cholesterol, and LDL cholesterol were lower in HFD-AA-fed mice than in those of HFD-fed mice.

CONCLUSIONS

These results suggest that ascorbic acid seems to suppress HFD-induced visceral obesity and NAFLD in part through the activation of PPARα.

Anti-Obesity Property of Lichen Thamnolia vermicularis Extract in 3T3-L1 Cells and Diet-Induced Obese Mice

Thamnolia vermicularis (TV) is an edible lichen that is prevalent in the alpine zone of East Asia. This study evaluated the feasibility of using TV acetone extracts as a functional food based on experiments using cell line and obese mice. The cellular triglyceride levels and Oil red O staining of 3T3-L1 cells indicated that TV extracts (5 and 10 μg/mL) dose-dependently suppressed adipocyte differentiation and lipid accumulation compared with the control. The TV extract (0.4%, w/w) in a high-fat diet (HFD) was supplemented to C57BL/6N mice for 12 weeks, and TV extract supplement significantly reduced visceral fat mass and body weight compared with HFD feeding alone. The TV extract also induced significant decreases in serum and hepatic lipids, whereas it increased the serum high-density lipoproteins-cholesterol/total cholesterol ratio and fecal lipids levels. Moreover, the TV extract led to significantly lower homeostasis model assessment of insulin resistance in diet-induced obese mice. Taken together, these results suggest that the TV extract may have anti-obesity effects, including lipid-lowering, and it is a natural resource with the potential for use in obesity management.

Do In Seung Gi‑Tang extract suppresses adipocyte differentiation in 3T3‑L1 cells

Blood stasis syndrome (BSS), additionally called Eohyul, is a basic pathological concept in Traditional Korean Medicine. Do In Seung Gi‑Tang (DISGT) is herbal medicine used for the treatment of BSS. It primarily treats metabolic diseases (MDs) including obesity, hypertension, diabetes mellitus and gynecological diseases, by promoting blood circulation. The present study aimed to investigate the anti‑adipogenesis effect of DISGT in 3T3‑L1 adipocytes using Oil Red O staining, and assessing levels of triglycerides (TGs) and leptin in adipocytes by ELISA and western blot analysis. The results demonstrated that DISGT treatment had inhibitory effects on fat droplet formation, TG accumulation, leptin production and cytokine content, during 3T3‑L1 adipocyte differentiation, without affecting cell viability. Additionally, DISGT treatment significantly suppressed the protein expression levels of peroxisome proliferator‑activated receptor γ and CAAT/enhancer binding protein α. These results provide evidence that DISGT has anti‑adipogenesis effects on preadipocytes and adipocytes by significantly blocking adipocyte differentiation and lipid accumulation, and suppressing adipogenic gene expression. Therefore, the present study demonstrated the potential of DISGT as a therapeutic agent for the treatment of MDs.

The effects of herbal composition Gambigyeongsinhwan (4) on hepatic steatosis and inflammation in Otsuka Long-Evans Tokushima fatty rats and HepG2 cells

ETHNOPHARMACOLOGICAL RELEVANCE

Hepatic steatosis has risen rapidly in parallel with a dramatic increase in obesity. The aim of this study was to determine whether the herbal composition Gambigyeongsinhwan (4) (GGH(4)), composed of Curcuma longa L. (Zingiberaceae), Alnus japonica (Thunb.) Steud. (Betulaceae), and the fermented traditional Korean medicine Massa Medicata Fermentata, regulates hepatic steatosis and inflammation.

MATERIALS AND METHODS

The effects of GGH(4) on hepatic steatosis and inflammation in Otsuka Long-Evans Tokushima fatty (OLETF) rats and HepG2 cells were examined using Oil red O, hematoxylin and eosin, and toluidine blue staining, immunohistochemistry, quantitative real-time polymerase chain reaction, and peroxisome proliferator-activated receptor α (PPARα) transactivation assay.

RESULTS

Administration of GGH(4) to OLETF rats improved hepatic steatosis and lowered serum levels of alanine transaminase, total cholesterol, triglycerides, and free fatty acids. GGH(4) increased mRNA levels of fatty acid oxidation enzymes (ACOX, HD, CPT-1, and MCAD) and decreased mRNA levels of lipogenesis genes (FAS, ACC1, C/EBPα, and SREBP-1c) in the liver of OLETF rats. In addition, infiltration of inflammatory cells and expression of inflammatory cytokines (CD68, TNFα, and MCP-1) in liver tissue were reduced by GGH(4). Treatment of HepG2 cells with a mixture of oleic acid and palmitoleic acid induced significant lipid accumulation, but GGH(4) inhibited lipid accumulation by regulating the expression of hepatic fatty acid oxidation and lipogenic genes. GGH(4) also increased PPARα reporter gene expression. These effects of GGH(4) were similar to those of the PPARα activator fenofibrate, whereas the PPARα antagonist GW6471 reversed the inhibitory effects of GGH(4) on lipid accumulation in HepG2 cells.

CONCLUSIONS

These results suggest that GGH(4) inhibits obesity-induced hepatic steatosis and that this process may be mediated by regulation of the expression of PPARα target genes and lipogenic genes. GGH(4) also suppressed obesity-related hepatic inflammation. Thus, GGH(4) may be a promising drug for the treatment of obesity-related liver diseases.

Identification of Picrasidine C as a Subtype-Selective PPARα Agonist

Picrasidine C (1), a dimeric β-carboline-type alkaloid isolated from the root of Picrasma quassioides, was identified to have PPARα agonistic activity by a mammalian one-hybrid assay from a compound library. Among the PPAR subtypes, 1 selectively activated PPARα in a concentration-dependent manner. Remarkably, 1 also promoted PPARα transcriptional activity by a peroxisome proliferator response element-driven luciferase reporter assay. Furthermore, 1 induced the expression of PPARα-regulated genes involved in lipid, glucose, and cholesterol metabolism, such as CPT-1, PPARα, PDK4, and ABCA1, which was abrogated by the PPARα antagonist MK-886, indicating that the effect of 1 was dependent on PPARα activation. This is the first report to demonstrate 1 to be a subtype-selective PPARα agonist with potential application in treating metabolic diseases, such as hyperlipidemia, atherosclerosis, and hypercholesterolemia.

Herbal composition Gambigyeongsinhwan (4) from Curcuma longa, Alnus japonica, and Massa Medicata Fermentata inhibits lipid accumulation in 3T3-L1 cells and regulates obesity in Otsuka Long-Evans Tokushima Fatty rats

ETHNOPHARMACOLOGICAL RELEVANCE

Adipocyte lipid accumulation due to impaired fatty acid oxidation causes adipocyte hypertrophy and adipose tissue increment, leading to obesity. The aim of this study was to determine the antiobesity effects of the herbal composition Gambigyeongsinhwan (4) (GGH(4)) composed of Curcuma longa L. (Zingiberaceae), Alnus japonica (Thunb.) Steud. (Betulaceae), and the fermented traditional Korean medicine Massa Medicata Fermentata.

MATERIALS AND METHODS

The effects of GGH(4) and the individual components on lipid accumulation in 3T3-L1 adipocytes and body weight gain in Otsuka Long-Evans Tokushima Fatty (OLETF) rats were examined using Oil red O staining, hematoxylin and eosin staining, quantitative real-time PCR, and peroxisome proliferator-activated receptor α (PPARα) transactivation assay.

RESULTS

GGH(4), individual components, and an active principle of Curcuma longa curcumin inhibited lipid accumulation and mRNA levels of adipocyte-specific genes (PPARγ, aP2, and C/EBPα) in 3T3-L1 adipocytes compared with control cells. Treatment with GGH(4), the individual components or curcmumin increased mRNA levels of mitochondrial (CPT-1, MCAD, and VLCAD) and peroxisomal (ACOX and thiolase) PPARα target genes. GGH(4) and the individual components also increased PPARα reporter gene expression compared with control cells. These effects were most prominent in GGH(4)-treated cells. However, the PPARα antagonist GW6471 reversed the inhibitory effects of GGH(4) on adipogenesis. An in vivo study showed that GGH(4) decreased body weight gain, adipose tissue mass, and visceral adipocyte size with increasing mRNA levels of adipose tissue PPARα target genes in OLETF rats.

CONCLUSIONS

These results demonstrate that GGH(4) has an antiobesity effects through the inhibition of adipocyte lipid accumulation, and this process may be mediated in part through adipose PPARα activation.

Dohaekseunggi-tang extract inhibits obesity, hyperlipidemia, and hypertension in high-fat diet-induced obese mice

Background

Dohaekseunggi-tang (DHSGT) is a traditional plant-based medicine prescribed to promote blood circulation and to treat obesity and hypertension. The present study aimed to identify potential anti-obesity activities of DHSGT extract.

Methods

Anti-obesity, anti-hyperlipidemic, and anti-hypertensive effects of orally-administered DHSGT extract were evaluated in high-fat diet- (HFD)-induced obese mice. Serum biochemistry profiles and expression of diverse metabolic regulatory gene mRNAs in mouse visceral fat were assessed by RT-PCR. The effects of DHSGT on angiotensin-1 converting enzyme (ACE) and pancreatic lipase activities were determined using in vitro inhibition assays.

Results

Oral DHSGT treatment reduced obese HFD C57BL/6 J mouse body weight, liver and adipose tissue mass, adipocyte size, and blood pressure versus untreated HFD mice. DHSGT also decreased serum total cholesterol, LDL-cholesterol, triglyceride, glucose, and leptin concentrations, and increased HDL-cholesterol and adiponectin levels in HFD mice. Furthermore, DHSGT markedly increased mRNA expression of peroxisome proliferator activated receptor-gamma, uncoupling protein-2, and adiponectin in visceral adipose tissue of HFD mice. In vitro tests revealed that DHSGT effectively inhibited porcine pancreatic lipase and ACE activities, with IC₅₀ values of 7.58 mg/ml and 0.56 mg/ml, respectively.

Conclusions

These results validate traditional knowledge and suggest that DHSGT may be potentially useful for managing hyperlipidemia, hyperglycemia, hypertension, and obesity.

Anti‑obesity effects of Actinidia polygama extract in mice with high‑fat diet‑induced obesity

Actinidia polygama has been used as a herbal folk medicine for treating pain, gout, rheumatoid arthritis and inflammation. In the present study, the anti‑obesity properties of Actinidia polygama extract (APE) were investigated in mice with high‑fat diet‑induced obesity. APE treatment of high‑fat diet (HFD)‑fed obese mice significantly reduced body weight, adipose tissue mass and serum triglyceride and leptin levels relative to the HFD‑fed mice. Food intake did not differ between the HFD and HFD+APE groups, although the food efficiency ratio (FER) was significantly decreased in the HFD+APE group compared with the HFD group. Histological examination showed that the sizes of the adipocytes were significantly smaller in the HFD+APE group compared with the HFD group. Serum levels of aspartate transaminase were significantly decreased in the HFD+APE mice compared with the HFD‑fed mice, but serum levels of alanine transaminase (ALT), blood urea nitrogen and creatinine were not significantly changed in the HFD+APE mice compared with the levels in the normal diet (ND)‑fed and HFD‑fed mice. These results suggest that APE may be useful for treating metabolic diseases, including obesity and hyperlipidemia, without toxic side‑effects.

Selenium significantly inhibits adipocyte hypertrophy and abdominal fat accumulation in OLETF rats via induction of fatty acid β-oxidation

A combination of selenium (Se) with other trace element is associated with partially modulate fatty acid distribution as well as reduction of the body weight and feed efficiency. To investigate whether or not Se treatment has an impact on lipid metabolism, we examined the levels of lipid metabolism-related factors, including abdominal fat, adiponectin, cholesterol, very long chain dehydrogenase (VLCAD), and medium chain acyl-CoA dehydrogenase (MCAD) in 20-week-old Otsuka Long-Evans Tokushima Fatty (OLETF) rats following sodium selenite treatment for 2 weeks. Herein, we observed that (a) Se treatment induced insulin-like effects by lowering the serum glucose level in rats; (b) Se-treated rats showed significance values decreases in abdominal fat mass, adipocyte size, and adiponectin, which are associated with lipid metabolism; (c) Se treatment led to reduced levels of cholesterol, triglycerides, low-density lipoprotein (LDL), and high-density lipoprotein (HDL) cholesterol; (d) fat tissue in Se-treated rats displayed significantly lower expression of adipocyte marker genes along with increased expression of VLCAD and MCAD; and (e) fatty liver formation and β-oxidation gene expression were both significantly reduced in liver tissue of Se-treated rats. Therefore, our results suggest that Se may induce inhibition of adipocyte hypertrophy and abdominal fat accumulation along with suppression of fatty liver formation by the differential regulation of the gene expression for fatty acid β-oxidation in the OLETF model.

Use of cereal bars with quinoa (Chenopodium quinoa W.) to reduce risk factors related to cardiovascular diseases

Quinoa is considered a pseudocereal with proteins of high biological value, carbohydrates of low glycemic index, phytosteroids, and omega-3 and 6 fatty acids that bring benefits to the human health. The purpose of this study was to investigate the effects of quinoa on the biochemical and anthropometric profile and blood pressure in humans, parameters for measuring risk of cardiovascular diseases. Twenty-two 18 to 45-year-old students were treated daily for 30 days with quinoa in the form of a cereal bar. Blood samples were collected before and after 30 days of treatment to determine glycemic and biochemical profile of the group. The results indicated that quinoa had beneficial effects on part of the population studied since the levels of total cholesterol, triglycerides, and LDL-c showed reduction. It can be concluded that the use of quinoa in diet can be considered beneficial in the prevention and treatment of risk factors related to cardiovascular diseases that are among the leading causes of death in today's globalized world. However, further studies are needed to prove the benefits observed.

Euchresta horsfieldii Benn. activates peroxisome proliferator-activated receptor α and regulates expression of genes involved in fatty acid metabolism in human HepG2 cells

AIM OF THE STUDY

Euchresta horsfieldii Benn., an oriental medicinal plant, has been used for the traditional treatment of hyperlipidemia and has been reported to possess bioactive isoflavones; however, the molecular mechanism underlying its hypolipidemic effects remains unclear. In the present study, we investigated the effect of Euchresta horsfieldii on peroxisome proliferator-activated receptor α (PPARα) activation and fatty acid metabolism in HepG2 hepatocytes.

MATERIALS AND METHODS

The dried Euchresta horsfieldii fruits were extracted with 100% ethanol, and the ethanol evaporated to produce Euchresta horsfieldii extract (EHX). The effect of EHX on fatty acid metabolism was evaluated by PPARα transactivation assay, real-time reverse transcription-polymerase chain reaction, and Western blot analysis.

RESULTS

We demonstrated that EHX significantly increased PPARα activation in a dose-dependent manner. In human HepG2 hepatocytes, EHX increased mRNA levels of the following genes involved in fatty acid oxidation: carnitine palmitoyltransferase 1, liver form (CPT1L), acyl-CoA synthetase (ACS), medium-chain acyl-CoA dehydrogenase (MCAD), 3-hydroxy-3-methylglutaryl-CoA synthase 2 (HMGCS2), acyl-CoA 1 (ACO1), acyl-CoA 2 (ACO2), and enoyl-CoA hydratase 1 (ECH1). EHX treatment also increased levels of proteins related to fatty acid oxidation, such as CPT1L, PPARα, and uncoupling protein 2 (UCP2). In contrast, sterol regulatory element binding protein 1 (SREBP1), a key lipogenic transcription factor, was downregulated.

CONCLUSION

Consistent with significant PPARα activation, EHX increased PPARα target genes expression and regulated protein expression for lipid metabolism. Taken together, these results indicate that Euchresta horsfieldii shows potential as a natural lipid-lowering agent.