Vitamin D Mitigates Hepatic Fat Accumulation and Inflammation and Increases SIRT1/AMPK Expression in AML-12 Hepatocytes.

Emerging evidence has demonstrated a strong correlation between vitamin D status and fatty liver disease. Aberrant hepatic fat infiltration contributes to oxidant overproduction, promoting metabolic dysfunction, and inflammatory responses. Vitamin D supplementation might be a good strategy for reducing hepatic lipid accumulation and inflammation in non-alcoholic fatty liver disease and its associated diseases. This study aimed to investigate the role of the most biologically active form of vitamin D, 1,25-dihydroxyvitamin D (1,25(OH)2D), in hepatic fat accumulation and inflammation in palmitic acid (PA)-treated AML-12 hepatocytes. The results indicated that treatment with 1,25(OH)2D significantly decreased triglyceride contents, lipid peroxidation, and cellular damage. In addition, mRNA levels of apoptosis-associated speck-like CARD-domain protein (ASC), thioredoxin-interacting protein (TXNIP), NOD-like receptor family pyrin domain-containing 3 (NLRP3), and interleukin-1ß (IL-1ß) involved in the NLRP3 inflammasome accompanied by caspase-1 activity and IL-1ß expression were significantly suppressed by 1,25(OH)2D in PA-treated hepatocytes. Moreover, upon PA exposure, 1,25(OH)2D-incubated AML-12 hepatocytes showed higher sirtulin 1 (SIRT1) expression and adenosine monophosphate-activated protein kinase (AMPK) phosphorylation. A SIRT1 inhibitor alleviated the beneficial effects of 1,25(OH)2D on PA-induced hepatic fat deposition, IL-1ß expression, and caspase-1 activity. These results suggest that the favorable effects of 1,25(OH)2D on hepatic fat accumulation and inflammation may be, at least in part, associated with the SIRT1.

Anti-Obesity Effects of Marine Macroalgae Extract Caulerpa lentillifera in a Caenorhabditis elegans Model.

Obesity is a multifactorial disease characterized by an excessive accumulation of fat, which in turn poses a significant risk to health. Bioactive compounds obtained from macroalgae have demonstrated their efficacy in combating obesity in various animal models. The green macroalgae Caulerpa lentillifera (CL) contains numerous active constituents. Hence, in the present study, we aimed to elucidate the beneficial anti-obesity effects of extracts derived from C. lentillifera using a Caenorhabditis elegans obesity model. The ethanol (CLET) and ethyl acetate (CLEA) extracts caused a significant decrease in fat consumption, reaching up to approximately 50-60%. Triglyceride levels in 50 mM glucose-fed worms were significantly reduced by approximately 200%. The GFP-labeled dhs-3, a marker for lipid droplets, exhibited a significant reduction in its level to approximately 30%. Furthermore, the level of intracellular ROS displayed a significant decrease of 18.26 to 23.91% in high-glucose-fed worms treated with CL extracts, while their lifespan remained unchanged. Additionally, the mRNA expression of genes associated with lipogenesis, such as sbp-1, showed a significant down-regulation following treatment with CL extracts. This finding was supported by a significant decrease (at 16.22-18.29%) in GFP-labeled sbp-1 gene expression. These results suggest that C. lentillifera extracts may facilitate a reduction in total fat accumulation induced by glucose through sbp-1 pathways. In summary, this study highlights the anti-obesity potential of compounds derived from C. lentillifera extracts in a C. elegans model of obesity, mediated by the suppression of lipogenesis pathways.

Effects of Melatonin Supplementation on Lipid Metabolism and Body Fat Accumulation in Ovariectomized Rats.

Postmenopausal obesity is a rising problem. Melatonin (Mel) is a hormone secreted by the pineal gland that regulates the circadian rhythms and improves obesity. In this experiment, ovariectomized (OVX) rats were used as a menopause model to explore the effects of Mel supplementation on lipid metabolism, body fat accumulation, and obesity. Nine-week-old female rats underwent an OVX surgery and were assigned to the following groups: control group (C), low-dose group (L, 10 mg/kg body weight (BW) Mel), medium-dose group (M, 20 mg/kg BW Mel), and high-dose group (H, 50 mg/kg BW Mel), administered by gavage for 8 weeks. The results showed that the OVX rats supplemented with low, medium, and high doses of Mel for 8 weeks exhibited reduced BW gain, perirenal fat mass, and gonads fat mass, and an increased serum irisin level. Low and high doses of Mel induced brite/beige adipocytes in the white adipose tissues. In addition, the messenger RNA levels of the fatty acid synthesis enzymes were significantly reduced after the high-dose Mel supplementation. Thus, Mel can reduce the hepatic fatty acid synthesis and promote the browning of white adipose tissues through irisin; thereby, improving obesity and body fat accumulation in OVX rats.

Effects of epigallocatechin gallate, caffeine, and their combination on fat accumulation in high-glucose diet-fed Caenorhabditis elegans.

Epigallocatechin gallate (EGCG) and caffeine are inevitable to be ingested together in the process of drinking green tea. This study used Caenorhabditis elegans as an organism model to examine whether the binding of EGCG and caffeine could influence the fat-reduction effect. The results revealed that EGCG significantly reduced the Nile Red fluorescence intensity and the triglyceride/protein ratio of the C. elegans obesity model by 14.7% and 16.5%, respectively, while the effect of caffeine was not significant. Moreover, the degree of reduction in fluorescence intensity and triglyceride/protein ratio by EGCG + caffeine was comparable to that of EGCG. In the exploration of underlying mechanism, we found that EGCG and EGCG + caffeine treatments had no influence on food intake and energy expenditure of C. elegans. Their fat-reduction effects were dependent on the regulation of lipogenesis, as shown by the decreased expression of the sbp-1, fat-7, and daf-16 genes.

Goishi tea leaf powder affects lower body weight and visceral fat accumulation during energy restriction in obese rats.

Goishi tea is a unique Japanese post-fermented tea produced in Kochi prefecture. The aim of this study was to investigate whether the supplementation of energy-restricted diet with Goishi tea leaves affects body weight, visceral fat accumulation, and fecal lipids in diet-induced obese rats. 18 male Wistar rats were fed a high-fat diet for 12 weeks. Subsequently, the diet-induced obese rats were fed a low-energy diet containing 1% (G1 group) or 3% (G3 group) of Goishi tea leaf powder, or without any tea extracts (C group) for 4 weeks. After 4 weeks, body weight and body fat ratio were significantly lower in the G3 group than in the C group. Plasma insulin levels were significantly higher in the C group than in the G1 and G3 groups, whereas plasma leptin levels were significantly lower in the G3 group than in the C group. In addition, the lipid absorption rate was significantly lower in the G3 group than in the C and G1 groups. In conclusion, the administration of Goishi tea leaves under dietary restrictions might contribute to body weight reduction and inhibition of lipid absorption, as a diet therapy to help prevent obesity and metabolic syndrome. J. Med. Invest. 70 : 60-65, February, 2023.

Antidiabetic and anti-obesity properties of a polyphenol-rich flower extract from Tagetes erecta L. and its effects on Caenorhabditis elegans fat storages.

Diabetes mellitus (DM) is a metabolic disease characterized by a high blood sugar level that can cause severe complications to the organism or even death when not treated. However, certain dietary habits and foods may have beneficial effects on this condition. A polyphenolic-rich extract (containing hyperoside, isoquercitrin, quercetin, ellagic acid, and vanillic acid) of Tageres erecta L. (T. erecta) was obtained from yellow and orange flowers using an ethanolic Soxhlet extraction. These extracts were screened for antidiabetic and anti-obesity properties using in vitro and in vivo procedures. The capacity to inhibit the enzymes lipase and α-glucosidase, as well as the inhibition of advance glycation end-products (AGEs) was tested in vitro. Caenorhabditis elegans (C. elegans) was used as an obesity in vivo model to assess extracts effects on fat accumulation using the wild-type strain N2 and a mutant with no N3 fatty acid desaturase activity BX24. Extracts from both cultivars (yellow and orange) T. erecta presented in vitro inhibitory activity against the enzymes lipase and α-glucosidase, showing lower IC50 values than acarbose (control). They also showed important activity in preventing AGEs formation. The polyphenol-rich matrices reduced the fat content of obese worms in the wild-type strain (N2) down to levels of untreated C. elegans, with no significant differences found between negative control (100% reduction) and both tested samples (p < 0.05). Meanwhile, the fat reduction was considerably lower in the BX24 mutants (fat-1(wa-9)), suggesting that N3 fatty acid desaturase activity could be partially involved in the T. erecta flower effect. Our findings suggested that polyphenols from T. erecta can be considered candidate bioactive compounds in the prevention and improvement of metabolic chronic diseases such as obesity and diabetes.

Effects of Pawpaw (Asimina triloba) Seed Extract on the Differentiation and Fat Accumulation of 3T3-L1 Cells under Different Glucose Conditions.

Asimina triloba (pawpaw) contains various bioactive alkaloids and acetogenins. In the present study, the effects of pawpaw seed extract (PSE) on adipocyte differentiation and fat accumulation were investigated in 3T3-L1 cells under different glucose conditions. Treatment of undifferentiated cells with 10 ng/mL PSE increased lactic acid production, suggesting enhanced anaerobic glycolysis. PSE treatment also suppressed cell proliferation and decreased the nicotinamide adenine dinucleotide (NAD)+/NADH ratio in low-glucose medium; however, this effect was not observed in high-glucose medium. Additionally, PSE treatment under low-glucose conditions resulted in reduced accumulation of triglycerides and decreased expression of peroxisome proliferator-activated receptor (PPAR)-γ, CAAT/enhancer-binding protein (C/EBP)-α, and sterol regulatory element binding protein (SREBP)-1c in adipocyte-differentiated cells. PSE exerted greater effects on adipocyte differentiation and triglyceride content in 3T3-L1 cells under low-glucose conditions than under high-glucose conditions. These findings indicate that PSE enhances anaerobic glycolysis and inhibits adipocyte differentiation and fat accumulation in 3T3-L1 cells under glucose-restricted conditions.

Naringin Alleviates Glucose-Induced Aging by Reducing Fat Accumulation and Promoting Autophagy in Caenorhabditis elegans.

Naringin (Nar) is a dihydroflavonoid compound, widely found in citrus fruit and used in Chinese herbal medicine. As a phytochemical, it acts as a dietary supplement that can delay aging and prevent aging-related disease, such as obesity and diabetes. However, its exact mechanism remains unclear. In this study, the high-glucose-induced (HGI) Caenorhabditis elegans model was used to evaluate the anti-aging and anti-obesity effects of Nar. The mean lifespan and fast movement span of HGI worms were extended roughly 24% and 11%, respectively, by Nar treatment. Oil red O staining revealed a significant reduction in fat accumulation and dFP::LGG-labeled worms showed the promotion of autophagy. Additionally, whole transcriptome sequencing and gene set variation analysis suggested that Nar upregulated the lipid biosynthesis and metabolism pathways, as well as the TGF-ß, Wnt and longevity signaling pathways. Protein-protein interaction (PPI) network analysis identified hub genes in these pathways for further analysis. Mutant worms and RNA interference were used to study mechanisms; the suppression of hlh-30, lgg-1, unc-51, pha-4, skn-1 and yap-1 disabled the fat-lowering, lifespan-prolonging, and health-promoting properties of Nar. Collectively, our findings indicate that Nar plays an important role in alleviating HGI-aging and anti-obesity effects by reducing fat accumulation and promoting autophagy.

Effects of supplemental tannic acid on growth performance, gut health, microbiota, and fat accumulation and optimal dosages of tannic acid in broilers.

This study was conducted to investigate the effects of different dosages of tannic acid (TA) on growth performance, nutrient digestibility, gut health, immune system, oxidative status, microbial composition, volatile fatty acids (VFA), bone mineral density, and fat digestion and accumulation in broilers and to find optimal dosages of TA for efficient growth and gut health in broilers. A total of 320 male Cobb500 broilers were randomly distributed to 4 treatments with 8 replicates including 1) tannic acid 0 (TA0): basal diet without TA; 2) tannic acid 0.5 (TA0.5): basal diet with 0.5 g/kg TA; 3) tannic acid 1.5 (TA1.5); and 4) tannic acid 2.5 (TA2.5). Supplemental TA at levels greater than 972 mg/kg tended to reduce BW on D 21 (p = 0.05). The TA2.5 had significantly lower apparent ileal digestibility (AID) of crude protein compared to the TA0 group. The AID of ether extract tended to be reduced by TA at levels greater than 525 mg/kg (p = 0.08). The jejunal lipase activities tended to be reduced by TA at levels less than 595.3 mg/kg (p = 0.09). TA linearly decreased goblet cell density in the crypts of the jejunum (p < 0.05) and reduced mRNA expression of mucin two at levels less than 784.9 mg/kg and zonula occludens two at levels less than 892.6 mg/kg (p < 0.05). The TA0.5 group had higher activities of liver superoxide dismutase compared to the TA0 group (p < 0.05). Bone mineral density and contents tended to be linearly decreased by TA (p = 0.05), and the ratio of lean to fat was linearly decreased (p < 0.01). Total cecal VFA production tended to be linearly reduced by TA at levels greater than 850.9 mg/kg (p = 0.07). Supplemental TA tended to increase the relative abundance of the phylum Bacteroidetes (p = 0.1) and decrease the relative abundance of the phylum Proteobacteria (p = 0.1). The relative abundance of the family Rikenellaceae was the lowest at 500 mg/kg TA, and the relative abundance of the family Bacillaceae was the highest at 1,045 mg/kg TA. Collectively, these results indicate that the optimum level of supplemental TA would range between 500 and 900 mg/kg; this range of TA supplementation would improve gut health without negatively affecting growth performance in broilers under antibiotic-free conditions.

Amycenone reduces excess body weight and attenuates hyperlipidaemia by inhibiting lipogenesis and promoting lipolysis and fatty acid ß-oxidation in KK-Ay obese diabetic mice.

Excess body weight and hyperlipidaemia cause severe health problems and have social implications. Amycenone is an active substance extracted from Yamabushitake mushrooms with no reports of its activity against excess body weight and hyperlipidaemia. This research clarifies the effects and mechanisms of action of amycenone on the inhibition of body weight excess and hyperlipidaemia attenuation using KK-Ay mice. Amycenone or water was administered to 8-week-old male KK-Ay mice by gavage for 8 weeks. Their body weight and food intake were recorded during the experiment. At the end of the experimental period, the mice were dissected, and blood samples, lipid metabolism-related organs and tissues were collected and stored for further analysis. Amycenone treatment suppressed body weight gain and improved serum levels of fasting blood glucose and non-esterified fatty acids. Additionally, serum and hepatic cholesterol and triacylglycerol levels were reduced after this treatment, whereas the phosphorylation levels of AMPK, PKA and HSL increased and the expression level of FAS decreased. The protein level of C/EBPß and gene expression level of Cpt1 were higher in the perirenal adipose tissue of amycenone-treated KK-Ay mice. Furthermore, amycenone phosphorylated AMPK, PKA and ACC, and PPARγ expression was lower in the mesenteric adipose tissue. The phosphorylation levels of AMPK, LKB1, PKA and ACC were also induced, and FAS expression level was reduced in the liver of the amycenone-treated group. Amycenone could reduce excess body weight and attenuate hyperlipidaemia in KK-Ay mice by inhibiting lipogenesis and promoting lipolysis through lipid metabolism pathway stimulation and fatty acid ß-oxidation acceleration.

A Combined Supplement of Probiotic Strains AP-32, bv-77, and CP-9 Increased Akkermansia mucinphila and Reduced Non-Esterified Fatty Acids and Energy Metabolism in HFD-Induced Obese Rats.

Obesity is referred to as a condition in which excess body fat has accumulated to an extent that it causes negative impacts on health. The formation of body fat is regulated by complicated networks in relation to energy metabolism, and gut microbiota have been regarded as a key player. Studies have shown that supplements of probiotics provide benefits to health, including an improvement in metabolic syndrome and the control of body weight. In the present study, three probiotic strains, AP-32, bv-77, and CP-9, stood out from nine candidates using a lipid consumption assay, and were subsequently introduced to further animal tests. A rodent model of obesity was induced by a high-fat diet (HFD) in Sprague-Dawley (SD) rats, and three probiotic strains were administered either separately or in a mixture. A low dose (5 × 109 CFU/kg/day) and a high dose (2.5 × 1010 CFU/kg/day) of probiotics were orally provided to obese rats. The bioeffects of the probiotic supplements were evaluated based on five aspects: (1) the body weight and growth rate; (2) ketone bodies, non-esterified fatty acids (NEFAs), and feed efficiency; (3) blood biochemistry; (4) fat content; and (5) gut microbiota composition. Our results demonstrated that the supplement of AP-32, CP-9, and bv-77 alleviated the increasing rate of body weight and prevented the elevation of NEFAs and ketone bodies in obese rats. Although the effect on fat content showed a minor improvement, the supplement of probiotics displayed significant improvements in HFD-induced poor blood biochemical characteristics, such as alanine aminotransferase (ALT), aspartate Transaminase (AST), and uric acid, within 4 weeks. Furthermore, the combined supplement of three strains significantly increased Akkermansia mucinphila as compared with three individual strains, while its enrichment was negatively correlated with NEFAs and energy metabolism. In general, a mixture of three probiotic strains delivered a better outcome than a single strain, and the high dose of supplements provided a more profound benefit than the low dose. In conclusion, three probiotic strains, AP-32, bv-77, and CP-9, can alleviate body fat formation in obese rats. Furthermore, a combined supplement of these three probiotic strains may have potential in treating or controlling metabolic disorders.

Effects of tannic acid supplementation on growth performance, gut health, and meat production and quality of broiler chickens raised in floor pens for 42 days.

A study was conducted to investigate the effects of tannic acid (TA) supplementation on growth performance, gut health, antioxidant capacity, gut microbiota, and meat yield and quality in broilers raised for 42 days. A total of 700 one-day-old male broiler chickens (Cobb500) were allocated into 5 treatments with 7 replicates of 20 birds per pen. There were five treatments: 1) tannic acid 0 (TA0: basal diet without TA); 2) tannic acid 0.25 (TA0.25: basal diet+0.25 g/kg TA); 3) tannic acid 0.5 (TA0.5: basal diet+0.5 g/kg TA); 4) tannic acid 1 (TA1: basal diet+1 g/kg TA); and 5) tannic acid 2 (TA2: basal diet+2 g/kg TA). The dietary phases included starter (D 0 to 18; crumble feed), grower (D 18 to 28; pellet feed), and finisher (D 28 to 42; pellet feed). On D 18, the supplementation of TA linearly reduced body weight (BW) and average daily feed intake (ADFI) (p < 0.05), and on D 28, the supplementation of TA linearly reduced BW, average daily gain (ADG), and feed conversion ratio (FCR) (p < 0.05). Relative mRNA expression of genes related to mucin production (MUC2), tight junction proteins (CLDN2 and JAM2), and nutrient transporters (B0AT1 and SGLT1) was linearly increased by the supplementation of TA (p < 0.05). The supplementation of TA tended to linearly increase the relative abundance of the family Enterobacteriaceae (p = 0.08) and quadratically increased the relative abundance of the families Lachnospiraceae and Ruminococcaceae in the cecal microbial communities (p < 0.05). On D 36, the ratio of the phyla Firmicutes and Bacteroidetes was quadratically reduced by the supplementation of TA (p < 0.05). On D 42, bone mineral density and the lean to fat ratio were linearly decreased by the supplementation of TA (p < 0.05). On D 43, total chilled carcass weight was linearly reduced (p < 0.05), and proportion of leg weight was increased by supplementation of TA (p < 0.05). The supplementation of TA linearly reduced pH of the breast meat (p < 0.05) and linearly increased redness (a*) (p < 0.05). Although the supplementation of TA positively influenced gut health and gut microbiota in the starter/grower phases, it negatively affected overall growth performance, bone health, and meat production in broilers on D 42.

Effects of Dietary Fatty Acid Composition on Lipid Metabolism and Body Fat Accumulation in Ovariectomized Rats.

BACKGROUND: Obesity is a state of excess energy storage resulting in body fat accumulation, and postmenopausal obesity is a rising issue. In this study using ovariectomized (OVX) rats, we mimicked low estrogen levels in a postmenopausal state in order to investigate the effects of different amounts and types of dietary fatty acids on body fat accumulation and body lipid metabolism. METHODS: At 9 weeks of age, rats (n = 40) were given an ovariectomy, eight of which were sham-operated to serve as a control group (S). We then divided OVX rats into four different intervention groups: diet with 5% soybean oil (C), and diet with 5% (L), 15% (M), and 20% (H) (w/w) experimental oil, containing 60% monounsaturated fatty acids (MUFAs) and with a polyunsaturated/saturated fatty acid (P/S) ratio of 5. RESULTS: After OVX, compared to the S group, the C group showed significantly higher body weight, and insulin and leptin levels. Compared to the C group, the H group had lower hepatic triglyceride level and FAS enzyme activity, and higher hepatic ACO and CPT-1 gene expressions and enzyme activities. CONCLUSIONS: An OVX leads to severe weight gain and lipid metabolism abnormalities, while according to previous studies, high fat diet may worsen the situation. However, during our experiment, we discovered that the experimental oil mixture with 60% MUFAs and P/S = 5 may ameliorate these imbalances.

Effects of Irregular Feeding on the Daily Fluctuations in mRNA Expression of the Neurosecretory Protein GL and Neurosecretory Protein GM Genes in the Mouse Hypothalamus.

Circadian desynchrony induced by a long period of irregular feeding leads to metabolic diseases, such as obesity and diabetes mellitus. The recently identified neurosecretory protein GL (NPGL) and neurosecretory protein GM (NPGM) are hypothalamic small proteins that stimulate food intake and fat accumulation in several animals. To clarify the mechanisms that evoke feeding behavior and induce energy metabolism at the appropriate times in accordance with a circadian rhythm, diurnal fluctuations in Npgl and Npgm mRNA expression were investigated in mice. Quantitative RT-PCR analysis revealed that the mRNAs of these two genes were highly expressed in the mediobasal hypothalamus during the active dark phase under ad libitum feeding. In mice restricted to 3 h of feeding during the inactive light phase, the Npgl mRNA level was augmented in the moment prior to the feeding period and the midnight peak of Npgm mRNA was attenuated. Moreover, the mRNA expression levels of clock genes, feeding regulatory neuropeptides, and lipid metabolic enzymes in the central and peripheral tissues were comparable to those of central Npgl and Npgm. These data suggest that Npgl and Npgm transcription fluctuates daily and likely mediates feeding behavior and/or energy metabolism at an appropriate time according to the meal timing.

Inhibition of preadipocyte differentiation by Lycium barbarum polysaccharide treatment in 3T3-L1 cultures

BACKGROUND: Lycium barbarum (also called wolfberry), a famous Chinese traditional medicine and food ingredient, is well recognized for its significant role in preventing obesity; however, the molecular mechanisms underlying its preventive effects on fat accumulation are not well understood yet. The aim of this study was to determine the effects and mechanism of Lycium barbarum polysaccharides (LBP) on the proliferation and differentiation of 3T3-L1 preadipocytes. MTT was used to detect the proliferation of 3T3-Ll preadipocytes. Oil red O staining and colorimetric analysis were used to detect cytosolic lipid accumulation during 3T3-L1 preadipocyte differentiation. Real-time fluorescent quantitative PCR (qPCR) technology was used to detect peroxisome proliferator-activated receptor c (PPARc), CCAAT/enhancer-binding protein a (C/EBPa), adipocyte fatty-acid-binding protein (aP2), fatty acid synthase (FAS), and lipoprotein lipase (LPL) expression. RESULTS: The concentration of LBP from 25 to 200 lg/mL showed a tendency to inhibit the growth of preadipocytes at 24 h, and it inhibited the differentiation of 3T3-L1 preadipocytes in a dose-dependent manner. In the preadipocytes treated with 200 lg/mL LBP, there were reduced lipid droplets in the cytoplasm, and its effect was opposite to that of rosiglitazone (ROS), which significantly reduced the PPARc, C/EBPa, aP2, FAS, and LPL mRNA expression of adipocytes. CONCLUSIONS: LBP exerts inhibitive effects on the proliferation and differentiation of 3T3-L1 preadipocytes and decreases the cytoplasm accumulation of lipid droplets during induced differentiation of preadipocytes toward mature cells. Above phenomenon might link to lowered expression of PPARc, C/EBPa, aP2, FAS, and LPL after LBP treatment. Thus, LBP could serve as a potential plant extract to treat human obesity or improve farm animal carcass quality via adjusting lipid metabolism.

High-Fat Diets with Differential Fatty Acids Induce Obesity and Perturb Gut Microbiota in Honey Bee.

HFD (high-fat diet) induces obesity and metabolic disorders, which is associated with the alteration in gut microbiota profiles. However, the underlying molecular mechanisms of the processes are poorly understood. In this study, we used the simple model organism honey bee to explore how different amounts and types of dietary fats affect the host metabolism and the gut microbiota. Excess dietary fat, especially palm oil, elicited higher weight gain, lower survival rates, hyperglycemic, and fat accumulation in honey bees. However, microbiota-free honey bees reared on high-fat diets did not significantly change their phenotypes. Different fatty acid compositions in palm and soybean oil altered the lipid profiles of the honey bee body. Remarkably, dietary fats regulated lipid metabolism and immune-related gene expression at the transcriptional level. Gene set enrichment analysis showed that biological processes, including transcription factors, insulin secretion, and Toll and Imd signaling pathways, were significantly different in the gut of bees on different dietary fats. Moreover, a high-fat diet increased the relative abundance of Gilliamella, while the level of Bartonella was significantly decreased in palm oil groups. This study establishes a novel honey bee model of studying the crosstalk between dietary fat, gut microbiota, and host metabolism.

Synthesis and Characterization of Novel Resveratrol Butyrate Esters That Have the Ability to Prevent Fat Accumulation in a Liver Cell Culture Model.

To facilitate broad applications and enhance bioactivity, resveratrol was esterified to resveratrol butyrate esters (RBE). Esterification with butyric acid was conducted by the Steglich esterification method at room temperature with N-ethyl-N'-(3-dimethylaminopropyl) carbodiimide (EDC) and 4-dimethyl aminopyridine (DMAP). Our experiments demonstrated the synthesis of RBE through EDC- and DMAP-facilitated esterification was successful and that the FTIR spectra of RBE revealed absorption (1751 cm-1) in the ester region. 13C-NMR spectrum of RBE showed a peak at 171 ppm corresponding to the ester group and peaks between 1700 and 1600 cm-1 in the FTIR spectra. RBE treatment (25 or 50 µM) decreased oleic acid-induced lipid accumulation in HepG2 cells. This effect was stronger than that of resveratrol and mediated through the downregulation of p-ACC and SREBP-2 expression. This is the first study demonstrating RBE could be synthesized by the Steglich method and that resulting RBE could inhibit lipid accumulation in HepG2 cells. These results suggest that RBE could potentially serve as functional food ingredients and supplements for health promotion.

Urtica dioica Whole Vegetable as a Functional Food Targeting Fat Accumulation and Insulin Resistance-a Preliminary Study in a Mouse Pre-Diabetic Model.

The shoot of Urtica dioica is used in several cultures as a vegetable or herb. However, not much has been studied about the potential of this plant when consumed as a whole food/vegetable rather than an extract for dietary supplements. In a 12-week dietary intervention study, we tested the effect of U. dioica vegetable on high fat diet induced obesity and insulin resistance in C57BL/6J mice. Mice were fed ad libitum with isocaloric diets containing 10% fat or 45% fat with or without U. dioica. The diet supplemented with U. dioica attenuated high fat diet induced weight gain (p < 0.005; n = 9), fat accumulation in adipose tissue (p < 0.005; n = 9), and whole-body insulin resistance (HOMA-IR index) (p < 0.001; n = 9). Analysis of gene expression in skeletal muscle showed no effect on the constituents of the insulin signaling pathway (AKT, IRS proteins, PI3K, GLUT4, and insulin receptor). Notable genes that impact lipid or glucose metabolism and whose expression was changed by U. dioica include fasting induced adipocyte factor (FIAF) in adipose and skeletal muscle, peroxisome proliferator-activated receptor-α (Ppar-α) and forkhead box protein (FOXO1) in muscle and liver, and Carnitine palmitoyltransferase I (Cpt1) in liver (p < 0.01). We conclude that U. dioica vegetable protects against diet induced obesity through mechanisms involving lipid accumulation and glucose metabolism in skeletal muscle, liver, and adipose tissue.

Dietary adzuki bean paste dose-dependently reduces visceral fat accumulation in rats fed a normal diet.

The aim of this study was to evaluate the dose-dependent effect of adzuki bean (Vigna angularis) paste (ABP) on visceral fat accumulation in rats. ABP is a rich source of indigestible carbohydrates (18.5%) with fiber and resistant starch (RS) contents of 14.5% and 4.0%, respectively. Animals were fed one of the following diets, control (CON), 30% ABP or 58.9% ABP for 28 days. The daily dietary energy intake was lowered (p < 0.05) and reduced visceral fat accumulation and lower serum lipid levels were observed in ABP fed groups. ABP consumption dose-dependently increased (p < 0.05) the daily fecal lipid and fecal acidic sterol excretions. On the other hand, cecal content and fecal moisture content in the 58.9% ABP group were greater (p < 0.05) than the CON group, while there was no significant difference between the two ABP fed groups. Both 30% and 58.9% ABP diets had significantly (p < 0.05) higher contents of cecal acetic, propionic and n-butyric acids, and lowered cecal pH, independently of the ABP dose. Microbial community data of rats fed ABP diets exhibited higher alpha-diversities than the rats fed CON diet, based on the Shannon Index and the number of observed species index, where the two ABP groups exhibited a similar alpha diversity. The weighted UniFrac-based principal coordinate analysis plot of cecal microbial community data showed that the ABP had a substantial effect on the cecal microbial composition. Furthermore, cecal bacterial 16S rRNA gene sequencing revealed that the ABP supplemented diets decreased the ratio of Firmicutes to Bacteroidetes. These findings suggested that the cecal fermentation of fiber and RS in ABP, might have decreased the energy intake, altered the gut microbiota composition, increased fecal lipid output, and thereby reduced fat accumulation in rats.

Low and high concentrations of butyrate regulate fat accumulation in chicken adipocytes via different mechanisms.

The present study investigated the effects of varying concentrations of sodium butyrate (SB) on fat accumulation and cell proliferation in chicken adipocytes. High and low serial concentrations of SB used significantly reduced adipocytic fat accumulation. However, they were observed to exhibit differences in cell morphology and distinctions in lipogenic genes expression profiles. At lower concentration (0.01 mM), fat accumulation was decreased with an associated downregulation in the expression of lipogenic genes, which was mediated by free fatty acid receptors (FFARs). Contarily, at higher concentration (1 mM), the fat droplets laden in adipocytes were enlarged, and this was accompanied with activation of lipogenic genes expression. However, the total accumulated fat was also decreased largely due to reduction in cell numbers, which was partially attributable to the reduction in histone deacetylase (HDAC) activity. Animal experiments further indicated that dietary supplementation of lower dose coated SB (0.1% wt/wt) inhibited fat deposition in livers and abdominal fat tissues of broilers, suggesting the potential application of sodium butyrate as feed additive in the regulation of fat deposition.