Therapeutic effects of Lingguizhugan decoction in a rat model of high-fat diet-induced insulin resistance

BACKGROUND Lingguizhugan(LGZG)decoction is a widely used classic Chinese medicine formula that was recently shown to improve high-fat diet(HFD)-induced insulin resistance(IR)in animal studies.AIM To assess the therapeutic effect of LGZG decoction on HFD-induced IR and explore the potential underlying mechanism.METHODS To establish an IR rat model,a 12-wk HFD was administered,followed by a 4-wk treatment with LGZG.The determination of IR status was achieved through the use of biochemical tests and oral glucose tolerance tests.Using a targeted metabolomics platform to analyze changes in serum metabolites,quantitative real-time PCR(qRT-PCR)was used to assess the gene expression of the ribosomal protein S6 kinase beta 1(S6K1).RESULTS In IR rats,LGZG decreased body weight and indices of hepatic steatosis.It effectively controlled blood glucose and food intake while protecting islet cells.Metabolite analysis revealed significant differences between the HFD and HFDLGZG groups.LGZG intervention reduced branched-chain amino acid levels.Levels of IR-related metabolites such as tryptophan,alanine,taurine,and asparagine decreased significantly.IR may be linked to amino acids due to the contemporaneous increase in S6K1 expression,as shown by qRT-PCR.CONCLUSIONS Our study strongly suggests that LGZG decoction reduces HFD-induced IR.LGZG may activate S6K1 via metabolic pathways.These findings lay the groundwork for the potential of LGZG as an IR treatment.

Monascus pilosus-fermented black soybean inhibits lipid accumulation in adipocytes and in high-fat diet-induced obese mice

Objective:To explore the anti-obesity effects and the mechanism of action of Monascus pilosus(M.pilosus)-fermented black soybean(MFBS)extracts(MFBSE)and MFBS powders(MFBSP)in adipocytes and high-fat diet(HFD)-induced obese mice,respectively.Methods:Black soybean was fermented with M.pilosus,and the main constituents in MFBS were analyzed by HPLC analysis.In vitro,MFBSE were examined for anti-adipogenic effects using Oil-Red O staining.In vivo,mice were fed a normal-fat diet(NFD)control,HFD control or HFD containing 1 g/kg MFBSP for 12 weeks,and then body weight gain and tissues weight measured.Real-time PCR and western blot assay were used to determine the mechanism of anti-adipogenic effects.Results:MFBSE inhibited lipid accumulation in 3T3-L1 adipocytes without exerting cell cytotoxicity.MFBSP treatment in HFD-fed mice significantly decreased the body weight gain compared with the HFD control mice.MFBSE and MFBSP treatment resulted in significantly lower mRNA levels of adipogenesis-related genes,such as peroxisome proliferator-activated receptorγ(PPARγ),fatty acid-binding protein 4(FABP4),and fatty acid synthase(FAS),in adipocytes and in white adipose tissue(WAT)of HFD-induced obese mice.Conclusions:These results suggest that the anti-obesity effects of MFBS are elicited by regulating the expression of adipogenesis-related genes in adipocytes and WAT of HFDinduced obese mice.

Effect of Soy Isoflavone Crude Extract Supplementation on High Fat Diet-induced Insulin Resistance in Ovariectomized Rats

Female Wister rats aged 8 weeks were randomly divided into sham operation group, ovariectomized （OVX） control group, and 20VX groups fed with soy isoflavone crude extract supplementation. The rats had free access to high fat diet and water for 9 weeks. No significant difference was found in body weight （BW）, total abdominal fat, food intake and food utilization rate between OVX control group and 20VX groups. However, the fasting blood glucose and blood lipid levels were significantly higher in 20VX groups than in OVX control group （P〈0.05）. Intraperitoneal glucose tolerance test （IGTI＂） showed that the area under AUC was smaller in 20VX groups than in OVX control group （P〈0.05）. These findings showed that soy isoflavone crude extract supplementation can improve glucose tolerance and prevent high fat diet-induced insulin resistance in ovariectomized rats.

Obese diet-induced mouse models of nonalcoholic steatohepatitis-tracking disease by liver biopsy

AIM:To characterize development of diet-induced nonalcoholic steatohepatitis(NASH)by performing live biopsy in wild-type and genetically obese mice.METHODS:Male wild-type C57BL/6J(C57)mice(DIO NASH)and male Lep ob/Lep ob(ob/ob)mice(ob/ob-NASH were maintained on a diet high in trans-fat(40%)fructose(22%)and cholesterol(2%)for 26 and 12 wk respectively.A normal chow diet served as control in C57 mice(lean chow)and ob/ob mice(ob/ob chow)After the diet-induction period,mice were liver biopsied and a blinded histological assessment of steatosis and fibrosis was conducted.Mice were then stratified into groups counterbalanced for steatosis score and fibrosi stage and continued on diet and to receive daily PO dosing of vehicle for 8 wk.Global gene expression in liver tissue was assessed by RNA sequencing and bioin formatics.Metabolic parameters,plasma liver enzyme and lipids(total cholesterol,triglycerides)as well a hepatic lipids and collagen content were measured b biochemical analysis.Non-alcoholic fatty liver disease activity score(NAS)(steatosis/inflammation/ballooningdegeneration)and fibrosis were scored.Steatosis and fibrosis were also quantified using percent fractional area.RESULTS:Diet-induction for 26 and 12 wk in DIONASH and ob/ob-NASH mice,respectively,elicited progressive metabolic perturbations characterized by increased adiposity,total cholesterol and elevated plasma liver enzymes.The diet also induced clear histological features of NASH including hepatosteatosis and fibrosis.Overall,the metabolic NASH phenotype was more pronounced in ob/ob-NASH vs DIO-NASH mice.During the eight week repeated vehicle dosing period,the metabolic phenotype was sustained in DIO-NASH and ob/ob-NASH mice in conjunction with hepatomegaly and increased hepatic lipids and collagen accumulation.Histopathological scoring demonstrated significantly increased NAS of DIO-NASH mice(0 vs4.7±0.4,P<0.001 compared to lean chow)and ob/ob-NASH mice(2.4±0.3 vs 6.3±0.2,P<0.001compared to ob/ob chow),respectively.Furthermore,fibrosis stage was significantly elevated for DIO-NASH mice(0 vs 1.2±0.2,P<0.05 compared to lean chow)and ob/ob NASH(0.1±0.1 vs 3.0±0.2,P<0.001compared to ob/ob chow).Notably,fibrosis stage was significantly(P<0.001)increased in ob/ob-NASH mice,when compared to DIO-NASH mice.CONCLUSION:These data introduce the obese dietinduced DIO-NASH and ob/ob-NASH mouse models with biopsy-confirmed individual disease staging as a preclinical platform for evaluation of novel NASH therapeutics.

Diet-Induced Thermogenesis

An immense amount of information has now accrued about the factors that influence the increment of heat and the efficiency with which the energy of food is used by different animal species. Heat increment is one of the major factors that decrease the efficiency of energy utilization. In growing animals, the free energy content of the basal ATP requirement is typically about one-third of dietary basal heat production （thermogenesis）. Thermogenesis is an evolutionary and biologically significant mechanism for adaptive, homeostatic heat production in animals, including shivering thermogenesis （ST）, nonshivering thermogenesis （NST）, diet-induced thermogenesis （DIT）, febrile response （fever）, and so on. The main focus of this review is on the effect of DIT on energy metabolism.

Bitter Melon Powder Protects against Obesity-associated Fatty Liver Disease by Improving Colonic Microenvironment in Rats with High-fat Diet-induced Obesity

This study explored how bitter melon powder （BMP） alters the colonic microenvironment during the development of obesity-associated fatty liver in rats. We observed that BMP effectively inhibited the body weight gain and lipid accumulation in the liver, ameliorated glucose intolerance, and increased the colon weight after an 8-week treatment compared to that in the high-fat diet （HFD） group. BMP significantly decreased fecal water toxicity towards HT-29 cells, as revealed by the cell counting kit （CCK）-8 assay results, and the mRNA expression of Toll-like receptor 4 （TLR4） in colon mucosa. Additionally, gut permeability in the BMP group was restored to normal levels. Finally, BMP alleviated the inflammatory state of the rat colon mucosa and liver tissues as well as the systemic inflammation.

Docosahexaenoic acid-rich fish oil prevented insulin resistance by modulating gut microbiome and promoting colonic peptide YY expression in diet-induced obesity mice

It is unclear how docosahexaenoic acid(DHA)improves insulin resistance via modulating gut microbiome in obese individuals.We used diet-induced obesity(DIO)mice as a model to study the effects of DHA-rich fish oil(DHA-FO)on host metabolic disorders and colonic microbiome.DHA-FO reduced fat deposition,regulated lipid profiles and alleviated insulin resistance in DIO mice.Probably because DHA-FO prevented the permeation of lipopolysaccharide across intestinal epithelial barrier,and promoted peptide YY(PYY)secretion via the mediation of short chain fatty acids receptor(FFAR2)in colon.Furthermore,DHA-FO might regulate PYY expression by reversing microbial dysbiosis,including increasing the abundance ofAkkermansia muciniphila and Lactobacillus,and suppressing the growth of Helicobacter.DHA-FO also altered gut microbial function(e.g."linoleic acid metabolism")associated with PYY expression(r>0.80,P<0.05).Herein,DHA-FO enhanced insulin action on glucose metabolism by altering gut microbiome and facilitating colonic PYY expression in DIO mice.

The Effects of Xylitol on Body Weight Loss Management and Lipid Profile on Diet-Induced Obesity Mice

Xylitol is an alternative sweetener which has been previously reported to have many beneficial effects such as prevention from dental caries, reduction of visceral fat and increased synthesis of collagen. However, its role in body weight loss management has not been uncovered before. This study sought to investigate the effects of xylitol on body weight loss management, blood glucose and lipid profile on diet-induced obesity (DOI) mice. Fifteen male mice were subjected to high fat diet (60 kcal%) and normal drinking water for 28 days and then randomly divided into three (control, glucose and xylitol) groups. Each group of mice was then fed with normal diet for another 28 days with supplied normal drinking water (control);glucose solution 10% and xylitol solution 10%. Body weight loss was found to be significantly high in xylitol mice (2.56 ± 0.21, p = 0.003) compared to the other two groups. Lowest blood glucose level was found in the control group mice with the mean 7.65 ± 0.10 (p = 0.001). Xylitol mice had also showed the lowest total cholesterol level (4.20 ± 0.90, p = 0.000) than the other groups, but highest in HDL level (2.72 ± 0.14, p = 0.000). In conclusion, these findings proved that xylitol has the potential to reduce body weight, lowering the blood glucose but yet increase the HDL level.

Effects of Maternal Linseed Oil Supplementation on Metabolic Parameters in Cafeteria Diet-induced Obese Rats

Because linseed oil may influence maternal and fetal metabolisms, we investigated its role in the modulation of lipid metabolism in cafeteria diet-induced obese rats and their offspring. Female Wistar rats were fed control or cafeteria food, which were either supplemented or not supplemented with linseed oil （5%） for I month before and during gestation. At parturition, serum and tissue lipids and enzyme activities were analyzed. Cafeteria diet induced adverse metabolic alterations in both mothers and offspring. Linseed oil improved metabolic status. In conclusion, linseed oil displayed health benefits by modulating tissue enzyme activities in both obese mothers and their newborns.

Calorie control increased vaspin levels of serum and periepididymal adipose tissue in diet-induced obese rats in association with serum free fatty acid and tumor necrosis factor alpha

Background Vaspin was recently identified as a novel adipokine that is predominantly secreted from adipose tissue and exerts insulin-sensitizing effects. This study was undertaken to elucidate the regulative effects of calorie control on the expression of vaspin and its potential mechanism.Methods Diet-induced obese Sprague Dawley （SD） rats were adopted as experimental models and accepted interventions of various ingestions and pioglitazone. Various differentiated stages of cultured 3T3-L1 cells were dealt with pioglitazone or TNFα in vitro for 48 hours to further verify findings in animal experiments.Results The rats were successfully induced into an obese experimental model with hyperinsulinemia, hyperlipidemia, and increased serum free fatty acid and TNFa by 12-week high-fat diet. It was found that depending on whether the rats were fed by a high-fat diet or a basal diet, there was extremely higher vaspin in the periepididymal fat pad than in subcutaneous adipose tissues by 16 weeks. Vaspin in sera and the periepididymal fat pad was much lower in rats with a high-fat diet than those with a basal diet （all P 〈0.05）, but vaspin in subcutaneous fat tissues was prone to increase in rats with a high-fat diet. A 4-week calorie restriction or pioglitazone on the obese rats resulted in a partial recovery of vaspin levels in sera and periepididymal adipose tissues, especially the latter revealed a more obvious superiority and increased vaspin levels of subcutaneous adipose. Surprisingly, the treatment of 4-week high-fat diet on non-obese rats did not significantly depress vaspin of sera and periepididymal adipose tissues. However, it is unknown if re-feeding generated the effect on vaspin levels of obese and non-obese rats on sera or adipose tissues. The correlation analysis showed that vaspin levels of serum and periepididymal fat tissues were negatively correlated with serum FFA, TNFα and insulin; meanwhile, there was a positive correlation between serum vaspin and vaspin of periepididymal fat tissues. Pioglitazone enhanced vaspin levels in cultured 3T3-L1 cells and supernatant in various differentiated stages, and this effect became more and more obvious along with the change of preadipocytes into mature fat cells. Administration of TNFα caused suppression on vaspin expression in differentiated stages of 3T3-L1 cells.Conclusions The present data indicated that a long-term high-fat diet could induce obesity metabolic syndrome in SD rats and finally lead to lower vaspin of sera and periepididymal fat, while pioglitazone and chronic calorie-control ingestion could enhance the production of vaspin. It was undoubtedly demonstrated that vaspin expression was strongly associated with insulin sensitivity, serum FFA, and TNFα.

TRPC5 is essential in endothelium-dependent contraction of aorta from diet-induced obese mice

The role of the Ca^(2+)-permeable ion channel TRPC5 in regulating vasocontraction in obesity is poorly understood.Here,we investigated whether TRPC5 contributes to vascular dysfunction in obesity by promoting endothelium-dependent contraction via activation of cytosolic phospholipase A2(cPLA_(2))in the aortic endothelial cells of obese mice.Acetylcholine-induced endothelium-dependent relaxation and contraction in the aorta were measured us-ing wire myography.PLA_(2)activity was measured by the fluorogenic PLA_(2)substrate Bis-BODIPY^(TM)FL C_(11)-PC.The intracellular Ca^(2+)level in response to acetylcholine was measured by Fluo-4 fluorescence.Endothelium-derived contracting factors were assessed by enzyme immunoassay.Diet-induced obesity(DIO)attenuated endothelium-dependent vasodilation,enhanced endothelium-dependent contraction(EDC),and increased the expression of TRPC5 in the mouse aorta.Activation of TRPC5 promoted EDC in the wild-type mouse aorta,whereas pharma-cological inhibition and genetic knockout of TRPC5 decreased EDC in the DIO mouse aorta.Moreover,cPLA_(2)phosphorylation and activity were higher in aortic endothelial cells from DIO mice,and this was attenuated by inhibition and knockout of TRPC5.Cyclooxygenase 2(COX-2)expression was increased in DIO mouse endothe-lium and was decreased by a TRPC5 inhibitor and knockout of TRPC5.Release of prostaglandins F_(2α(PGF_(2α)and E 2(PGE 2)was involved in TRPC5-regulated EDC in DIO mice.This study demonstrated that TRPC5 contributes to endothelial and vascular dysfunction and is involved in EDC through activation of cPLA_(2)and enhanced COX-2-PGF_(2α)/PGE_(2)levels in DIO mice.

Effect of rAd-p53 on glucose metabolism in diet-induced and genetic T2DM mice

Objective To explore the possible mechanism of rAd-p53 involved in glucose metabolism by observing the different effects of rAd-p53 on high-fat diet(HFD)fed with low-dose streptozotocin(STZ)treated(HFD/STZ)mice(β-cell dysfunction model)and db/db mice(genetic insulin resistance model).Methods The established HFD/STZ and db/db diabetic mice were respectively

Changes of Neuronal Activities after Gut Electrical Stimulation with Different Parameters and Locations in Lateral Hypothalamus Area of Obese Rats

This study tested the effects of the gastrointestinal pulse train electrical stimulation with different parameters and at different locations on the neuronal activities of the lateral hypothalamus area（LHA） in obese rats in order to find the optimal stimulation parameter and location. Eight gastric electrical stimulations（GES） with different parameters were performed and the neuronal activities of gastric-distension responsive（GD-R） neurons in LHA were observed. The effects of stimulations with 8 parameters were compared to find the optimal parameter. Then the optimal parameter was used to perform electrical stimulation at duodenum and ileum, and the effects of the duodenal and ileac stimulation on the GD-R neurons in LHA were compared with the gastric stimulation of optimal parameter. The results showed that GES with the lowest energy parameter（0.3 ms, 3 mA, 20 Hz, 2 s on, 3 s off） activated the least neurons. The effects of GES with other parameters whose pulse width was 0.3 ms were not significantly different from those of the lowest energy parameter. Most gastric stimulations whose pulse width was 3 ms activated more LHA neurons than the smallest energy parameter stimulation, and the effects of those 3 ms gastric stimulations were similar. Accordingly, the lowest energy parameter was recognized as the optimal parameter. The effects of stimulations with the optimal parameter at stomach, duodenum and ileum on the LHA neuronal activities were not different. Collectively, gastrointestinal electrical stimulation（GIES） with relatively large pulse width might have stronger effects to the neuronal activities of GD-R neurons in LHA of obese rats. The effects of the GIES at different locations（stomach, duodenum and ileum） on those neurons are similar, and GES is preferential because of its easy clinical performance and safety.

Effect of mango seed kernel extract on the adipogenesis in 3T3-L1 adipocytes and in rats fed a high fat diet

Mangoes (Mangifera indica L.) are one of the most important tropical foods. The seed is one of the main by-products of mango processing. Therefore, it is important to find an economically viable use for this waste (e.g., as a food additive or supplement with high nutraceutical value). We investigated the anti-obesity effects of mango seed kernel extract with hot water (MSKE-W) in 3T3-L1 adipocytes and in a high fat diet (HFD)-induced obesity rat model. MSKE-W caused a significant decrease in the activity of glycerol 2-phosphate dehydrogenase in 3T3-L1 adipocytes without eliciting cell cytotoxicity and inhibited cellular lipid accumulation through down-regulation of transcription factors such as PPARγ and C/EBPα. In the animal model, rats fed an HFD containing 1% MSKE-W gained less weight than rats fed an HFD alone. The visceral fat mass in rats fed an HFD containing 1% MSKE-W tended to be lower than that in rats fed an HFD alone. Furthermore, histological examination of rat livers from an HFD showed steatohepatitis. However, rats on an HFD containning 1% MSKE-W showed no histopathological changes in liver tissue. Our results indicate that MSKE-W influences anti-obesity effects, both in vitro and in vivo, and suggest that MSKE-W provides a novel preventive potential against obesity.

Supplements of an aqueous combination of Justicia adhatoda and Ocimum tenuiflorum boost antioxidative effects and impede hyperlipidemia

Background: Justicia adhatoda and Ocimum tenuiflorum, locally known as bashok and tulsi, are two ethnomedicinally important herbs that have been using as dietary supplements for several therapeutic applications. This study evaluated the combined effect of both the herbs as an antioxidative and antihyperlipidemic agent.Methods: Antihyperlipidemic effect was assessed in a high-fat diet-induced hyperlipidemic model in Wistar albino rats. The rats were treated orally with extracts of bashok(J adhatoda, 200 mg/kg bw), tulshi(O tenuiflorum, 200 mg/kg bw), and a combination of bashok and tulshi(50:50), as well as with a reference drug, atorvastatin(10 mg/kg/day), with or without high-fat diet for 14 days. The antioxidative effect was studied using established in vitro models. The studies were supported by experimentally testing the effects of the extracts on membrane stabilization and inhibition of protein denaturation.Results: The results showed that the serum lipid profile was significantly decreased in the different treatment groups, with bashok having the greatest effect. Body weights, total serum protein, LDH, and relative liver and adipose tissue weights were markedly restored towards baseline values, the lowest atherogenic index being achieved with the combined extract. The combination treatment significantly enhanced total phenolic content and antioxidative capacity and greatly potentiated membrane stabilization, but inhibition of protein denaturation was not significantly affected.Conclusion: The data demonstrate that a combination of Justicia adhatoda and Ocimum tenuiflorum could be developed as a food supplement with antioxidative and antihyperlipidemic benefits.

Comparative study on the difference of obesity model induced by two kinds of high fat diet in Sprague-Dawley rats

Objective: To explore the differences of obese Sprague-Dawley(SD)rats model induced by lard oil high-fat(HF)diet or purified HF diet. Methods: SD weanling rats were randomly divided into three groups: D1 group,where rats were fed by lard oil HF diet;D2 group,where rats were fed by purified HF diet;C group,where rats were fed on chow. After 12 weeks,diet-induced obesity rat(stop 33% based on weight)were selected for further study,and the rest rats from group D1 and D2 were excluded. The food intake and weight were weighted daily and weekly,respectively. The subcutaneous,visceral and total fat contents of rats was measured by 256-row CT scan and the Lee index was calculated accordingly. The kidney,liver,testis,spleen and heart were weighted respectively. Serum leptin and insulin levels were quantified. The pathology in liver and adipose tissues were analyzed by HE staining. Oral glucose tolerance test(OGTT)was used to compare the glucose tolerance ability. Serum total cholestero(lT-CHO),high density lipoprotein(HDL-C),low density lipoprotein(LDL-C),triglyceride(TG)and inflammatory cytokines IL-6,TNF-α were detected as well. Results: After 12 weeks,the body weight,subcutaneous fat,visceral fat,total fat mass,wet weight of liver,kidney and heart,area under blood glucose curve and the levels of serum insulin,leptin,T-CHO,LDL-C,TG,IL-6 and TNF-α in group D2 were significantly increased compared to those of group C and group D1. HDL-C of group D2 was markedly lower than that in group C(P<0. 05). The visceral fat,total fat content and HDL-C in group D1 were significantly different from those of group C(P<0. 05). Steatosis and enlarged adipocyte were found in the livers of rats in group D1 and D2,and the lesions were more significant in group D2. Conclusion: Purified HF diet was more effective in inducing metabolic abnormalities,steatosis,peripheral chronic inflammation in obese SD rat models. But lard oil HF diet was more economical when only inducing visceral steatosis was required.

Reducing obesity and inflammation in mice with organically-derivatized polyoxovanadate clusters

Obesity,characterized by the dysregulation of energy balance in adipose tissue and other metabolic organs,is frequently accompanied by chronic low-grade inflammation.As long-acting insulin sensitizers,the organically-derivatized polyoxovanadates(POVs),can extend the dosing interval of antidiabetic drugs from hourly to almost daily.In this work,the protective activity of POVs is investigated by an eight-week in vivo experiment,in which a small amount of POVs was administrated orally to a mouse model of dietinduced obesity every day.The present study shows that administration of POVs significantly decreases the body weight of mice,reduces adipose tissue accumulation,and simultaneously reduces adipose tissue inflammation.In addition,the anti-obesogenic population of i NKT cells is protected potentially by POVs,which subsequently alleviates visceral adipose tissue inflammation in high-fat-diet(HFD)-fed mice against diet-induced obesity.By contrast,the change in body weight after POV treatment is the result of a substantial reduction in fat mass,with no obvious effects on lean body mass.These findings demonstrate that supplementary of POVs would be an effective way to combat obesity and metabolic disorders while lowering metabolic inflammation.

Impact of obese levels on the hepatic expression of nuclear receptors and drug-metabolizing enzymes in adult and offspring mice

The prevalence of obesity-associated conditions raises new challenges in clinical medication.Although altered expression of drug-metabolizing enzymes(DMEs)has been shown in obesity,the impacts of obese levels(overweight,obesity,and severe obesity)on the expression of DMEs have not been elucidated.Especially,limited information is available on whether parental obese levels affect ontogenic expression of DMEs in children.Here,a high-fat diet(HFD)and three feeding durations were used to mimic different obese levels in C57BL/6 mice.The hepatic expression of five nuclear receptors(NRs)and nine DMEs was examined.In general,a trend of induced expression of NRs and DMEs(except for Cyp2c29 and 3a11)was observed in HFD groups compared to low-fat diet(LFD)groups.Differentialeffects of HFD on the hepatic expression of DMEs were found in adult mice at different obese levels.Family-based dietary style of an HFD altered the ontogenic expression of DMEs in the offspring older than 15 days.Furthermore,obese levels of parental mice affected the hepatic expression of DMEs in offspring.Overall,the results indicate that obese levels affected expression of the DMEs in adult individuals and that of their children.Drug dosage might need to be optimized based on the obese levels.