Marcos Hiromu Okuda

Decaffeinated green tea extract rich in epigallocatechin-3-gallate prevents fatty liver disease by increased activities of mitochondrial respiratory chain complexes in diet-induced obesity mice

Nonalcoholic fatty liver disease has been considered the hepatic manifestation of obesity. It is unclear whether supplementation with green tea extract rich in epigallocatechin-3-gallate (EGCG) influences the activity of mitochondrial respiratory chain complexes and insulin resistance in the liver. EGCG regulated hepatic mitochondrial respiratory chain complexes and was capable of improving lipid metabolism, attenuating insulin resistance in obese mice. Mice were divided into four groups: control diet+water (CW) or EGCG (CE) and hyperlipidic diet+water (HFW) or EGCG (HFE). All animals received water and diets ad libitum for 16 weeks. Placebo groups received water (0.1 ml/day) and EGCG groups (0.1 ml EGCG and 50 mg/kg/day) by gavage. Cytokines concentrations were obtained by ELISA, protein expression through Western blotting and mitochondrial complex enzymatic activity by colorimetric assay of substrate degradation. HFW increased body weight gain, adiposity index, retroperitoneal and mesenteric adipose tissue relative weight, serum glucose, insulin and Homeostasis Model Assessment of Basal Insulin Resistance (HOMA-IR); glucose intolerance was observed in oral glucose tolerance test (OGTT) as well as ectopic fat liver deposition. HFE group decreased body weight gain, retroperitoneal and mesenteric adipose tissue relative weight, HOMA-IR, insulin levels and liver fat accumulation; increased complexes II-III and IV and malate dehydrogenase activities and improvement in glucose uptake in OGTT and insulin sensitivity by increased protein expression of total AKT, IRα and IRS1. We did not find alterations in inflammatory parameters analyzed. EGCG was able to prevent obesity stimulating the mitochondrial complex chain, increasing energy expenditure, particularly from the oxidation of lipid substrates, thereby contributing to the prevention of hepatic steatosis and improved insulin sensitivity.

Green tea extract improves high fat diet-induced hypothalamic inflammation, without affecting the serotoninergic system

To investigate possible mechanisms of green teas anti-obesity and anti-diabetic effects in the hypothalamus, the central regulator of metabolism, of mice fed with high-fat diet (HFD), we analyzed proteins of the toll-like receptor 4 (TLR4) pathway and serotoninergic proteins involved in energy homeostasis. Thirty-day-old male Swiss mice were fed with HFD rich in saturated fat and green tea extract (GTE) for 8 weeks. After that, body weight and mass of fat depots were evaluated. Oral glucose tolerance test was performed 3 days prior to euthanasia; serum glucose, insulin and adiponectin were measured in fasted mice. Hypothalamic TLR4 pathway proteins, serotonin receptors 1B and 2C and serotonin transporter were analyzed by Western blotting or enzyme-linked immunosorbent assay. A second set of animals was used to measure food intake in response to fluoxetine, a selective serotonin reuptake inhibitor. Mice fed with HFD had increased body weight and mass of fat depots, impaired oral glucose tolerance, elevated glucose and insulin and decreased adiponectin serum levels. TLR4, IκB-α, nuclear factor κB p50 and interleukin 6 were increased by HFD. Concomitant GTE treatment ameliorated these parameters. The serotoninergic system remained functional after HFD treatment despite a few alterations in protein content of serotonin receptors 1B and 2C and serotonin transporter. In summary, the GTE attenuated the deleterious effects of the HFD investigated in this study, partially due to reduced hypothalamic inflammation.

Decaffeinated green tea extract rich in epigallocatechin-3-gallate improves insulin resistance and metabolic profiles in normolipidic diet-but not high-fat diet-fed mice

Supplementation with epigallocatechin-3-gallate (EGCG), which restores metabolic profiles, has been proposed as an option for preventing and treating obesity. We investigated whether decaffeinated green tea extract rich in EGCG, attenuates high-fat diet (HFD)-induced metabolic alterations in Swiss mice. The mice were maintained on either a control diet (CD) or HFD for 8 weeks and supplemented with either a placebo or EGCG (50mg/kg/day). Body weight, serum lipid profiles, cytokine protein expression, and content in epididymal (EPI) and retroperitoneal (RET) adipose tissues, and adipocyte area were measured. The body weights of HFD + placebo-fed mice were increased compared with those of HFD + EGCG-fed mice (28 and 21%, respectively), whereas the body weights of CD + EGCG-fed mice were decreased 16% compared with those of the CD + placebo group. Serum triglyceride levels were decreased 32% in the CD + EGCG group compared with the CD + placebo group. Compared with the CD + placebo group, increased phosphorylation of AMPK and hormone-sensitive lipase in EPI and RET, respectively, was found in the CD + EGCG group. Increased acetyl-CoA carboxylase phosphorylation was observed in both adipose tissues. In addition, TNF-α and IL-10 levels in EPI and adiponectin levels were higher in the CD + EGCG group than in the CD + placebo group. TNF-α levels were lower in the HFD + EGCG group than in the HFD + placebo group. Furthermore, the CD + EGCG group exhibited a lower adipocyte area than the CD + placebo group. These indicate that the effects of decaffeinated green tea extract on body mass may be related to the crosstalk between lipolytic and inflammatory pathways in normolipidic diet-fed mice but not in HFD-fed mice.

Effects of a Diet Enriched with Polyunsaturated, Saturated, or Trans Fatty Acids on Cytokine Content in the Liver, White Adipose Tissue, and Skeletal Muscle of Adult Mice

This study analyzed the effect of diet enriched with 30% lipids on cytokines content in different tissues. Swiss male mice were distributed into four groups treated for 8 weeks with control (C, normolipidic diet); soybean oil (S); lard (L); and hydrogenated vegetable fat (H). We observed an increase in carcass fat in groups S and L, and the total amount of fatty deposits was only higher in group L compared with C group. The serum levels of free fatty acids were lower in the L group, and insulin, adiponectin, lipid profile, and glucose levels were similar among the groups. IL-10 was lower in group L in mesenteric and retroperitoneal adipose tissues. H reduced IL-10 only in retroperitoneal adipose tissue. There was an increase in IL-6 in the gastrocnemius muscle of the L group, and a positive correlation between TNF-α and IL-10 was observed in the livers of groups C, L, and H and in the muscles of all groups studied. The results suggested relationships between the quantity and quality of lipids ingested with adiposity, the concentration of free fatty acids, and cytokine production in white adipose tissue, gastrocnemius muscle, and liver.

Oligofructose supplementation (10%) during pregnancy and lactation does not change the inflammatory effect of concurrent trans fatty acid ingestion on 21-day-old offspring

BackgroundPreviously, we demonstrated that trans fatty acid ingestion during pregnancy and lactation caused a pro-inflammatory effect on the newborn. The opposite effect was described for gestational prebiotic intake. In the present study, we examined whether supplementation of the diet of the dams with 10% of oligofructose with or without hydrogenated vegetable fat during pregnancy and lactation affected the pro-inflammatory status on the pups at age 21 days.MethodsOn the first day of pregnancy, rats were divided into four groups, each of which received one of four diets: a control diet (C group), a control diet supplemented with 10% oligofructose (CF group), a diet enriched with hydrogenated vegetable fat containing trans fatty acids (T group) or a diet enriched with hydrogenated vegetable fat containing trans fatty acids supplemented with 10% oligofructose (TF group). The pups were weighed at birth and at 7, 14 and 21 days of life and were euthanized on post-natal day 21. The serum glucose, insulin and adiponectin concentrations were analyzed. The IL-6, IL-10 and TNF-α contents of the retroperitoneal white adipose tissue, liver, soleus and extensor digital longus muscles were analyzed by ELISA. The results are presented as the means ± standard error of the mean. Statistical significance was assessed using two-way ANOVA, followed by Tukeys test and considered significant at p < 0.05ResultsThe body weights of the 21-day old pups in the CF and TF groups were significant lower than those of the C (27% and 21%) and T (25% and 19%, respectively) groups. The serum levels of adiponectin in the CF, T and TF groups were lower than in the C group (41%; 34% and 31%, respectively). In the retroperitoneal adipose tissue, the IL-6 content was increased in TF group relative to the C and CF groups (74% for both), and the TNF-α content was higher in the T and TF groups than in the C group (62% and 98%, respectively). In the liver, the TNF-α (56% and 104%) and IL-10 (52% and 73%) contents were increased in the CF group relative to the C and TF groups.ConclusionsSupplementation of the diet of the dams with 10% of oligofructose during pregnancy and lactation, independent of supplementation with hydrogenated vegetable fat, adversely affected the development of the offspring and contributed to development of a pro-inflammatory status in the pups on postnatal day 21.

Oligofructose supplementation during pregnancy and lactation impairs offspring development and alters the intestinal properties of 21-d-old pups

BackgroundPreviously, we showed that the intake of trans fatty acids during pregnancy and lactation triggers a pro-inflammatory status in the offspring. On the other hand, prebiotics can alter the intestinal environment, reducing serum lipopolysaccharides (LPS) concentrations. This study evaluated the effect of the oligofructose 10% diet supplementation in the presence or absence of hydrogenated vegetable fat during pregnancy and lactation on the development, endotoxemia and bacterial composition of 21-d-old offspring.MethodsOn the first day of pregnancy rats were divided into four groups: control diet (C), control diet supplemented with 10% oligofructose (CF), diet enriched with hydrogenated vegetable fat, rich in TFA (T) or diet enriched with hydrogenated vegetable fat supplemented with 10% oligofructose (TF). Diets were maintained during pregnancy and lactation. At birth, 7th, 14th and 21th, pups were weighed and length was measured. Serum concentrations of LPS and free fatty acids (FFA) were performed by specific kits. Bacterial DNA present in faeces was determined by real-time PCR. Data were expressed as mean ± standard error of the mean and the statistical analysis was realized by ANOVA two-way and ANOVA for repeated measures. p < 0.05 was considered significant.ResultsWe observed that the oligofructose (10%) supplementation during pregnancy and lactation reduced body weight, body weight gain, length and serum FFA in the CF and TF group compared to C and T group respectively, of the 21-day-old offspring, accompanied by an increase in serum LPS and genomic DNA levels of lactobacillus spp. on faeces of the CF group in relation to C group.ConclusionIn conclusion, dam’s diet supplementation with 10% of oligofructose during pregnancy and lactation, independent of addition with hydrogenated vegetable fat, harms the offspring development, alters the bacterial composition and increases the serum concentrations of lipopolysaccharides in 21d-old pups.

Maternal Supplementation with Oligofructose (10%) during Pregnancy and Lactation Leads to Increased Pro-Inflammatory Status of the 21-D-Old Offspring

Previously, we showed that oligofructose (10%) supplementation during pregnancy and lactation increased endotoxemia in 21-d-old pups. The present study evaluated the effect of 10% oligofructose diet supplementation during pregnancy and lactation in the presence or absence of hydrogenated vegetable fat on the pro-inflammatory status of 21-d-old offspring. On the first day of pregnancy, female Wistar rats were divided into the following groups: control diet (C), control diet supplemented with 10% oligofructose (CF), diet enriched with hydrogenated vegetable fat (T) or diet enriched with hydrogenated vegetable fat supplemented with 10% oligofructose (TF). Diets were maintained during pregnancy and lactation. Serum TNF-α (tumor necrosis factor alpha) was assessed using a specific kit. Protein expression was determined by Western Blotting, and the relative mRNA levels were analyzed by RT-PCR (real-time polymerase chain reaction). We observed that 10% oligofructose supplementation during pregnancy and lactation increased offspring’s IL-6R (interleukin-6 receptor) mRNA levels in the liver and RET (retroperitoneal white adipose tissue) and decreased ADIPOR2 (adiponectin receptor 2) and ADIPOR1 (adiponectin receptor 1) gene expression in liver and EDL (extensor digital longus)/ SOL (soleus) muscles of CF group. Additionally, TF group presented with increased serum TNF-α, protein expression of p-NFκBp65 (phosphorylated form of nuclear factor kappa B p65 subunit) in liver and IL-6R mRNA levels in RET. These findings were accompanied by decreased levels of ADIPOR1 mRNA in the EDL and SOL muscles of the TF group. In conclusion, supplementing the dam’s diet with 10% of oligofructose during pregnancy and lactation, independent of hydrogenated vegetable fat addition, contributes to the increased pro-inflammatory status of 21-d-old offspring, possibly through the activation of the TLR4 (toll like receptor 4) pathway.