Probiotic attributes and prevention of LPS-induced pro-inflammatory stress in RAW264.7 macrophages and human intestinal epithelial cell line (Caco-2) by newly isolated Weissella cibaria strains.

Probiotic lactic acid bacteria are known to modulate gut associated immune responses. Not many studies have reported on the role of Weissella species in preventing lipopolysaccharide (LPS) induced proinflammatory stress in murine macrophages as well as in human intestinal epithelial cells (Caco-2). Therefore, the present study was taken up to evaluate the probiotic attributes of four newly isolated Weissella strains (two each from fermented dosa batter and a human infant faecal sample); these attributes are cholesterol reduction, adhesion to Caco-2 cells and mucin and their ability to prevent LPS-induced nitric oxide and proinflammatory cytokine (IL-6, IL-1ß and TNFα) production by the murine macrophages and IL-8 production by the human epithelial cells. Reduction in LPS induced pro-inflammatory stress was compared with a well-studied probiotic bacterium Lactobacillus rhamnosus GG. The results suggested that the strains were tolerant to gastric conditions (pH 3.0) and bile salts. In addition, the strains exhibited moderate cell surface hydrophobicity, cholesterol reduction and adhesion to Caco-2 cells and gastric mucin. All the strains could prevent LPS-induced nitric oxide and IL-6 production in murine macrophages, while strain 28 alone prevented IL-1ß production. All the strains could prevent IL-8 production by the human epithelial cells. The present study led to the first line selection of W. cibaria 28 as a putative strain for future studies as it showed adhesion to Caco-2 cells and gastric mucin and cholesterol reduction besides preventing LPS-induced pro-inflammatory stress in macrophages and in human colonic epithelial cells.

Kodo millet whole grain and bran supplementation prevents high-fat diet induced derangements in a lipid profile, inflammatory status and gut bacteria in mice.

The protective role of kodo millet whole grain and bran supplementation in diet induced obesity has not been investigated. Here we have studied the role of kodo millet supplementation in age matched Swiss albino mice that were randomly divided into groups and fed their respective diets for 16 weeks. A high fat diet increased weight gain, reduced glucose tolerance, increased serum lipids, altered hepatic and adipocyte gene expression and caused dysbiosis in the intestinal beneficial bacteria. Kodo millet supplementation did not affect weight gain but it improved glucose tolerance and prevented an increase in the serum cholesterol and lipid parameters (P ≤ 0.05), modulated adipogenesis related gene expression, decreased serum IL-6 and LPS levels (P ≤ 0.05), promoted selected beneficial gut bacterial abundances (Lactobacillus sp., Bifidobacteria, Akkermansia and Roseburia spp.) and improved the total short chain fatty acid production (P ≤ 0.05) and acetate levels (P ≤ 0.05) in cecal contents. This study provides evidence that kodo millet supplementation alleviates high-fat diet induced changes and hence can be incorporated as a functional ingredient for the management of obesity.

Cinnamaldehyde supplementation prevents fasting-induced hyperphagia, lipid accumulation, and inflammation in high-fat diet-fed mice.

Cinnamaldehyde, a bioactive component of cinnamon, is increasingly gaining interest for its preventive and therapeutic effects against metabolic complications like type-2 diabetes. This study is an attempt to understand the effect of cinnamaldehyde in high-fat diet (HFD)-associated increase in fasting-induced hyperphagia and related hormone levels, adipose tissue lipolysis and inflammation, and selected cecal microbial count in mice. Cinnamaldehyde, at 40 µM dose, prevented lipid accumulation and altered gene expression toward lipolytic phenotype in 3T3-L1 preadipocyte cell lines. In vivo, cinnamaldehyde coadministration prevented HFD-induced body weight gain, decreased fasting-induced hyperphagia, as well as circulating leptin and leptin/ghrelin ratio. In addition to that, cinnamaldehyde altered serum biochemical parameters related to lipolysis, that is, glycerol and free fatty acid levels. At transcriptional level, cinnamaldehyde increased anorectic gene expression in hypothalamus and lipolytic gene expression in visceral white adipose tissue. Furthermore, cinnamaldehyde also decreased serum IL-1ß and inflammatory gene expression in visceral white adipose tissue. However, cinnamaldehyde did not modulate the population of selected gut microbial (Lactobacillus, Bifidibaceria, and Roseburia) count in cecal content. In conclusion, cinnamaldehyde increased adipose tissue lipolysis, decreased fasting-induced hyperphagia, normalized circulating levels of leptin/ghrelin ratio, and reduced inflammation in HFD-fed mice, which augurs well for its antiobesity role.

Female PAPP-A knockout mice are resistant to metabolic dysfunction induced by high-fat/high-sucrose feeding at middle age.

Longevity and aging are influenced by common intracellular signals of the insulin/insulin-like growth factor (IGF)-1 pathway. Abnormally high levels of bioactive IGF-1 increase the development of various cancers and may contribute to metabolic diseases such as insulin resistance. Enhanced availability of IGF-1 is promoted by cleavage of IGF binding proteins (IGFBPs) by proteases, including the pregnancy-associated plasma protein-A (PAPPA). In vitro, PAPP-A is regulated by pro-inflammatory cytokines (PICs) such as interleukin (IL)-6 and tumor necrosis factor (TNF). Mice born with deficiency of the Papp-a gene (PAPP-A knockout (KO) mice) live ~30-40 % longer than their normal littermates and have decreased bioactive IGF-1 on standard diets. Our objective was to elucidate how the effects of high-fat, high-sucrose diet (HFHS) promote obesity, induce metabolic dysfunction, and alter systemic cytokine expression in PAPP-A KO and normal mice. PAPP-A KO mice fed HFHS diet for 10 weeks were more glucose tolerant and had enhanced insulin sensitivity compared to normal mice fed HFHS diet. PAPP-A KO mice fed HFHS diet had lower levels of pro-inflammatory cytokines (IL-2, IL-6, and TNF-α) compared to normal mice fed the same diet. However, anti-inflammatory cytokine levels (IL-4 and adiponectin) were higher in PAPP-A KO mice fed HFHS diet compared to normal mice fed HFHS. Circulating PAPP-A levels were elevated in normal mice fed an HFHS diet compared to normal mice fed a standard, low-fat, low-sucrose (LFLS) diet. Indirect calorimetry showed, at 10 weeks of feeding HFHS diet, significantly increased oxygen consumption (VO2) in PAPP-A KO mice fed HFHS diet compared to normal mice fed the same diet. Furthermore, respiratory quotient (RQ) was significantly lower in PAPP-A KO mice fed HFHS diet compared to normal (N) mice fed HFHS diet indicating PAPP-A KO mice fed HFHS diet are able to rely on fat as their primary source of energy more so than normal controls. We conclude that PAPP-A KO mice are resistant to the HFHS diet induction of metabolic dysfunction associated with higher levels of anti-inflammatory cytokines and a remarkably metabolic flexible phenotype and that some of the effects of HFHS diet in normal animals may be due to increased levels of PAPP-A.

Hepatocellular alterations and dysregulation of oncogenic pathways in the liver of transgenic mice overexpressing growth hormone.

Growth hormone (GH) overexpression throughout life in transgenic mice is associated with the development of liver tumors at old ages. The preneoplastic pathology observed in the liver of young adult GH-overexpressing mice is similar to that present in humans at high risk of hepatic cancer. To elucidate the molecular pathogenesis underlying the pro-oncogenic liver pathology induced by prolonged exposure to elevated GH levels, the activation and expression of several components of signal transduction pathways that have been implicated in hepatocellular carcinogenesis were evaluated in the liver of young adult GH-transgenic mice. In addition, males and females were analyzed in parallel in order to evaluate sexual dimorphism. Transgenic mice from both sexes exhibited hepatocyte hypertrophy with enlarged nuclear size and exacerbated hepatocellular proliferation, which were higher in males. Dysregulation of several oncogenic pathways was observed in the liver of GH-overexpressing transgenic mice. Many signaling mediators and effectors were upregulated in transgenic mice compared with normal controls, including Akt2, NFκB, GSK3ß, ß-catenin, cyclin D1, cyclin E, c-myc, c-jun and c-fos. The molecular alterations described did not exhibit sexual dimorphism in transgenic mice except for higher gene expression and nuclear localization of cyclin D1 in males. We conclude that prolonged exposure to GH induces in the liver alterations in signaling pathways involved in cell growth, proliferation and survival that resemble those found in many human tumors.