Natural Products in Anti-Obesity Therapy

Brown adipocyte activation mediates lipid metabolism through exosomal tRNA-derived fragments

Human obesity is related with intrinsic impairments of adipocyte lipolysis and ectopic lipid accumulation. Small regulatory RNAs, such as tRNA-derived fragments (tRFs) and tRNA halves (tiRNAs), are enriched in exosomes and play a crucial role in lipid metabolism. To determine certain tRFs for lipolysis, brown adipocytes were treated with forskolin. Using tRFs sequencing, 207 different expressed exosomal tRFs were determined. In forskolin samples, 145 downregulated and 62 upregulated tRFs were identified. Further, qRT-PCR validated that three notably upregulated tRFs (tRF-Gly-GCC-007, tRF-Gly-GCC-008, and tRF-Gly-GCC-009) were in accordance with the sequencing result. Target genes of tRFs were involved in positive regulation of protein phosphorylation and cell adhesion process by significantly downregulating UCHL1 expression, which might participate in lipolysis. This study might provide therapeutic targets and potential diagnostic biomarkers for obesity treatment.

Evaluation of the Anti-Obesity Effect of Zeaxanthin and Exercise in HFD-Induced Obese Rats

Obesity is a worldwide epidemic associated with many health problems. One of the new trends in health care is the emphasis on regular exercise and a healthy diet. Zeaxanthin (Zea) is a carotenoid with many beneficial effects on human health. The aim of this study was to investigate whether the combination of Zea and exercise had therapeutic effects on obesity induced by an HFD in rats. Sixty male Wistar rats were randomly divided into five groups of twelve: rats fed a standard diet; rats fed a high-fat diet (HFD); rats fed an HFD with Zea; rats fed an HFD with Exc; and rats fed an HFD with both Zea and Exc. To induce obesity, rats were fed an HFD for twelve weeks. Then, Zea and exercise were introduced with the HFD for five weeks. The results showed that the HFD significantly increased visceral adipose tissue, oxidative stress, and inflammation biomarkers and reduced insulin, high-density lipoprotein, and antioxidant parameters. Treatments with Zea, Exc, and Zea plus Exc reduced body weight gain, triacylglycerol, glucose, total cholesterol, and nitric oxide levels and significantly increased catalase and insulin compared with the HFD group. This study demonstrated that Zea administration and Exc performance appeared to effectively alleviate the metabolic alterations induced by an HFD. Furthermore, Zea and Exc together had a better effect than either intervention alone.

Pharmacological Activity of Garcinia indica (Kokum): An Updated Review

Garcinia indica (commonly known as kokum), belonging to the Clusiaceae family (mangosteen family), is a tropical evergreen tree distributed in certain regions of India. It has been used in culinary and industrial applications for a variety of purposes, including acidulant in curries, pickles, health drinks, wine, and butter. In particular, G. indica has been used in traditional medicine to treat inflammation, dermatitis, and diarrhea, and to promote digestion. According to several studies, various phytochemicals such as garcinol, hydroxycitric acid (HCA), cyanidin-3-sambubioside, and cyanidin-3-glucoside were isolated from G. indica, and their pharmacological activities were published. This review highlights recent updates on the various pharmacological activities of G. indica. These studies reported that G. indica has antioxidant, anti-obesity, anti-arthritic, anti-inflammatory, antibacterial, hepatoprotective, cardioprotective, antidepressant and anxiolytic effects both in vitro and in vivo. These findings, together with previously published reports of pharmacological activity of various components isolated from G. indica, suggest its potential as a promising therapeutic agent to prevent various diseases.

Effect of Forskolin on Body Weight, Glucose Metabolism and Adipocyte Size of Diet-Induced Obesity in Mice

The purpose of this study was to investigate the effects of forskolin on body weight, glucose metabolism and fat cell diameter in high-fat diet-induced obese mice. Four-week-old male mice (C57BL/6) were randomly assigned to 1 of 3 treatment groups: a high-fat diet plus 5% dimethyl sulfoxide (vehicle), high-fat diet plus 2 mg/kg of forskolin (dissolved in 5% dimethyl sulfoxide) and high-fat diet plus 4 mg/kg of forskolin (dissolved in 5% dimethyl sulfoxide). Forskolin or dimethyl sulfoxide was administered intraperitoneally every two days. The results indicated that no significant difference was observed in the body weight, feed intake and serum lipid parameters among groups at 20 weeks of age. The blood glucose levels were significantly reduced in the groups treated with 2 mg/kg of forskolin before glucose tolerance test. Forskolin administration linearly decreased blood glucose levels of high-fat diet-fed mice at 90 min and total area under curve (AUC) after insulin tolerance test. The subcutaneous adipocyte diameter was significantly reduced in the groups treated with 2 mg/kg of forskolin. Forskolin administration linearly reduced the gonadal adipocyte diameter of high-fat diet-fed mice. Forskolin significantly reduced the differentiation of murine mesenchymal stem cells into adipocytes and this was accompanied by a decrease in intracellular triglyceride content and an increase in glycerol concentration in the culture medium. The subcutaneous adipocyte diameter, gonadal adipocyte diameter and total AUC of insulin tolerance test were moderately negatively correlated with the concentration of forskolin in the high-fat diet-induced obese model. These results demonstrate that forskolin can regulate glucose metabolism and reduce fat cell diameter of high-fat diet-fed mice and inhibit the adipocyte differentiation of murine mesenchymal stem cells.

Effect of Deglycosylated Rutin by Acid Hydrolysis on Obesity and Hyperlipidemia in High-Fat Diet-Induced Obese Mice

The present study evaluated the effects of acid-treated rutin on hyperlipidemia and obesity in high-fat diet (HFD)-induced obese mice. The mice consumed a HFD with or without acid-treated rutin for 7 weeks. Body weight gain considerably decreased, by approximately 33%, in the acid-treated rutin (AR) and quercetin (Q) groups compared to that in the HFD group. The adipocytes' size in epididymal fat in AR and Q groups was significantly reduced compared to that in the HFD group (p < 0.05). Treatment with AR decreased the levels of triglycerides, total cholesterol, and low-density lipoprotein cholesterol compared to the HFD group. In particular, administration of AR significantly decreased serum triglyceride (36.82 mg/dL) by 46% compared to HFD (69.30 mg/dL). The AR group also showed significantly decreased atherogenic indices and cardiac risk factors. These results suggest that deglycosylated rutin generated by acid treatment enhances the anti-obesity and hypolipidemic effects in obese mice, and provides valuable information for improving the functional properties of glycosidic flavonoids.

Bioactivity-Guided Isolation and Identification of Anti-adipogenic Constituents from the n-Butanol Fraction of Cissus quadrangularis

Obesity is marked by the buildup of fat in adipose tissue that increases body weight and the risk of many associated health problems, including diabetes and cardiovascular disease. Treatment options for obesity are limited, and available medications have many side effects. Thus there is a great need to find alternative medicines for treating obesity. This study explores the anti-adipogenic potential of the n-butanol fraction of Cissus quadrangularis (CQ-B) on 3T3-L1 mouse preadipocyte cell line. The expression of various lipogenic marker genes such as adiponectin, peroxisome proliferator-activated receptor gamma, leptin, fatty acid-binding proteins, sterol regulatory element-binding proteins, fetal alcohol syndrome, steroyl-CoA desaturase-1, lipoproteins, acetyl-CoA carboxylase alpha, and acetyl-CoA carboxylase beta were variously significantly downregulated. After establishing the anti-adipogenic potential of CQ-B, it was fractionated to isolate anti-adipogenic compounds. We observed significant reduction in neutral lipid content of differentiated cells treated with various fractions of CQ-B. Gas chromatography-mass spectrometry analysis revealed the presence of thirteen compounds with reported anti-adipogenic activities. Further studies to purify these compounds can offer efficacious and viable treatment options for obesity and related complications.

Effect of Enzymatic Treatment of Chrysanthemum indicum Linné Extracts on Lipid Accumulation and Adipogenesis in High-Fat-Diet-Induced Obese Male Mice

Enzyme treatment of the foods and herbs has been used to improve the absorption rate the efficiency of plant extracts by converting the glycosides of the plant into aglycones. In this study, we examined the obesity-inhibitory effect of Chrysanthemum indicum Linné (CI) treated with enzymes such as viscozyme and tannase, which are highly efficient in converting glycosides to aglycones and then compared with untreated CI extract. The enzyme-treated CI ethanol extract (CIVT) was administered orally at various doses for 7 weeks in the high fat diet (HFD)-fed male mice. CIVT administration reduced the body weights, the food efficiency and the serum levels of lipid metabolism-related biomarkers, such as triglycerides (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-c) and leptin in the dose-dependent manner but not those high-density lipoprotein cholesterol (HDL-c) and adiponectin. CIVT also reduced considerably the total lipid amount in the liver and the size of adipocytes in the epididymal white adipose tissue (eWAT). CIVT effectively downregulated the adipogenesis-related transcription factors such as peroxisome proliferation activated receptor (PPAR)-γ and CCAAT/enhancer binding protein-α (C/EBP-α) but up-regulated PPAR-α, in the liver and eWAT. In addition, when compared to the enzyme-untreated CI 50% ethanol extract (CIEE), CIVT enhanced the reduction of body weight and lipid accumulation. Moreover, the viscozyme and tannase treatment of CI increased the flavonoid contents of the aglycone form. Therefore, our results support that the enzymatic treatment induced the production of aglycones for potentially suppressing the adipogenesis and lipid accumulation in HFD-fed mice. It suggests that CIVT might be an effective candidate for attenuating the over-weight and its related diseases.

Milk Fat Globule Membrane Attenuates High-Fat Diet-Induced Obesity by Inhibiting Adipogenesis and Increasing Uncoupling Protein 1 Expression in White Adipose Tissue of Mice

Milk fat globule membrane (MFGM), a protein-lipid complex surrounding the fat globules in milk, has many health benefits. The aim of the current study was to investigate whether MFGM could prevent obesity through inhibiting adipogenesis and promoting brown remodeling of white adipose tissue (WAT) in mice fed with high-fat diet. C57BL/6 mice were fed a normal diet (ND), high-fat diet (HFD), HFD plus MFGM at 100 mg/kg BW, 200 mg/kg BW or 400 mg/kg BW for 8 weeks. Results showed that MFGM suppressed body weight gain induced by HFD, reduced white adipose tissue (WAT) mass accompanied with the decrease in adipocyte sizes. MFGM was found to have partially improved serum lipid profiles, as well as to have suppressed HFD-induced adipogenesis as shown by reduced expression of peroxisome proliferators-activator receptor-γ (PPARγ), CCAAT/enhancer-binding protein-α (C/EBPα) and sterol regulatory element-binding protein-1c (SREBP-1c). MFGM also markedly increased the phosphorylation of AMP-activated protein kinase (AMPK) and acetyl-CoA carboxylase (ACC), showing activation of AMPK pathway. Moreover, MFGM promoted browning of inguinal WAT by upregulation the protein expression of uncoupling protein 1 (UCP1) in HFD mice. Taken together, these findings provide evidence that MFGM may protect against diet-induced adiposity by suppressing adipogenesis and promoting brown-like transformation in WAT.