The Effect of Lactobacillus sakei on Growth Performance and Intestinal Health in Dogs: Gut Microbiota and Metabolism Study.

The gut microbiota is the largest and most complex ecosystem consisting of trillions of microorganisms, which influenced by various external factors. As an important probiotic species, Lactobacillus helps to improve gut microbial diversity and composition, underlying potential efficacy in growth performance and disease prevention. However, limited studies have been investigated the relationship between Lactobacillus sakei and intestinal health in dogs. In this study, dogs in the two groups were fed a standard diet (group C, n = 8) and Lactobacillus sakei diet (group P, n = 8), respectively. The growth performance, serum biochemical indices, antioxidant capacity, gut microbiota, and metabolism of dogs in both groups were studied. Results from growth trials showed that L. sakei can significantly improve the growth performance of dogs, including increased weight gain (p < 0.05), serum biochemical indices, i.e., ALP, TP, and ALB (p < 0.05), and better antioxidant capacity, i.e., SOD and GSH-Px (p < 0.05). Significant changes in the gut microbial composition were detected in dogs fed Lactobacillus sakei, as evidenced by an increase in the level of Firmicutes, Spirochaetota, and Patescibacteria, all of them play an important role in maintaining intestinal health. Moreover, a decrease in the level of microorganisms that threaten health, such as Mucispirillum and Clostridium_sensu_stricto_13. The metabolic analysis showed that the Lactobacillus sakei enhanced metabolic pathways such as vitamin B6 metabolism, glutathione metabolism, retinol metabolism, and fatty acid degradation. Our findings suggested that Lactobacillus sakei supplementation had beneficial effects on the growth performance and health status of dogs by improving gut microbiota balance and promoting metabolism. There are an estimated 200 million dogs in China, and the population is continuing to grow at a rapid pace. It is essential to explore an effective way to promote health in dogs. Intestinal diseases, particularly colitis and diarrhea, are common clinical conditions in dogs and are associated with gut microbiota. Lactobacillus sakei, as an important species of probiotics, the relationship between L. sakei and intestinal health in dogs remains unclear. Our study suggests that L. sakei significantly promotes growth performance and health states involving weight gain, regulation of gut microbiota, and metabolism. Overall, our findings shed light on the potential role of L. sakei as an alternative in promoting health in dogs.

Time-restricted feeding prevents metabolic diseases through the regulation of galanin/GALR1 expression in the hypothalamus of mice.

PURPOSE: Time-restricted feeding (TRF) reverses obesity and insulin resistance, yet the central mechanisms underlying its beneficial effects are not fully understood. Recent studies suggest a critical role of hypothalamic galanin and its receptors in the regulation of energy balance. It is yet unclear whether TRF could regulate the expression of galanin and its receptors in the hypothalamus of mice fed a high-fat diet. METHODS: To test this effect, we subjected mice to either ad lib or TRF of a high-fat diet for 8 h per day. After 4 weeks, galanin and many neuropeptides associated with the function of metabolism were examined. RESULTS: The present findings showed that mice under TRF consume equivalent calories from a high-fat diet as those with ad lib access, yet are protected against obesity and have improved glucose metabolism. Plasma galanin, orexin A, irisin and adropin levels were significantly reversed by TRF regimen. Besides, TRF regimen reversed the progression of metabolic disorders in mice by increasing GLUT4 and PGC-1α expression in skeletal muscles. Moreover, the levels of galanin and GALR1 expression were severely diminished in the hypothalamus of the TRF mice, whereas GALR2 was highly expressed. CONCLUSIONS: TRF diminished galanin and GALR1 expression, and increased GALR2 expression in the hypothalamus of mice fed a high-fat diet. The current studies provide additional evidence that TRF is effective in improving HFD-induced hyperglycemia and insulin resistance in mice, and this effect could be associated with TRF-induced changes of the galanin systems in the hypothalamus. LEVEL OF EVIDENCE: No level of evidence, animal studies.

Baicalin protects against insulin resistance and metabolic dysfunction through activation of GALR2/GLUT4 signaling.

BACKGROUND: Type 2 diabetes mellitus is a complex metabolic disorder associated with obesity, glucose intolerance and insulin resistance. Activation of GALR2 has been proposed as a therapeutic target for the treatment of insulin resistance. The previous studies showed that baicalin could mitigate insulin resistance, but the detailed mechanism of baicalin on insulin resistance has not been fully explored yet. PURPOSE: In the present study, we evaluated whether baicalin mitigated insulin resistance via activation of GALR2 signaling pathway. STUDY DESIGN/METHODS: Baicalin (25 mg/kg/d and 50 mg/kg/d) and/or GALR2 antagonist M871 (10 mg/kg/d) were injected individually or in combinations into obese mice once a day for three weeks, and normal and GALR2 knockdown myotubes were treated with baicalin (100 µM and 400 µM) or metformin (4 mM) in the absence or presence of M871 (800 nM) for 12 h, respectively. The molecular mechanism was explored in skeletal muscle and L6 myotubes. RESULTS: The present findings showed that baicalin mitigated hyperglycemia and insulin resistance and elevated the levels of PGC-1α, GLUT4, p-p38MAPK, p-AKT and p-AS160 in skeletal muscle of obese mice. Strikingly, the baicalin-induced beneficial effects were abolished by GALR2 antagonist M871 in obese mice. In vitro, baicalin dramatically augmented glucose consumption and the activity of PGC1α-GLUT4 axis in myotubes through activation of p38MAPK and AKT pathways. Moreover, baicalin-induced elevations in glucose consumption related genes were abolished by GALR2 antagonist M871 or silencing of GALR2 in myotubes. CONCLUSIONS: The present study for the first time demonstrated that baicalin protected against insulin resistance and metabolic dysfunction mainly through activation of GALR2-GLUT4 signal pathway. Our findings identified that activation of GALR2-GLUT4 signal pathway by baicalin could be a new therapeutic approach to treat insulin resistance and T2DM in clinic.

A promising biomarker of elevated galanin level in hypothalamus for osteoporosis risk in type 2 diabetes mellitus.

Type 2 diabetes mellitus (T2DM) and osteoporosis are two major healthcare problems worldwide. T2DM is considered to be a risk factor for osteoporosis. Interestingly, several epidemiological studies suggest that bone abnormalities associated with diabetes may differ, at least in part, from those associated with senile or post-menopausal osteoporosis. The growing prevalence that patients with T2DM simultaneously suffer from osteoporosis, puts forward the importance to discuss the relationship between both diseases, as well as to investigate correlative agents to treat them. Emerging evidences demonstrate that neuropeptide galanin is involved in the pathogenesis of T2DM and osteoporosis. Galanin via activation of central GALR2 increases insulin sensitivity as well as bone density and mass in animal models. The disorder of galanin function plays major role in development of both diseases. Importantly, galanin signaling is indispensable for ΔFosB, an AP1 antagonist, to play the bone mass-accruing effects in the ventral hypothalamic neurons of diabetic models. This review summarizes our and other recent studies to provide a new insight into the multivariate relationship among galanin, T2DM and osteoporosis, highlighting the beneficial effect of galanin on the comorbid state of both diseases. These may help us better understanding the pathogenesis of osteoporosis and T2DM and provide useful clues for further inquiry if elevated galanin level may be taken as a biomarker for both conjoint diseases, and GALR2 agonist may be taken as a novel therapeutic strategy to treat both diseases concurrently.

Baicalin and its aglycone: a novel approach for treatment of metabolic disorders.

BACKGROUND: The current strategies for prevention and treatment of insulin resistance and type 2 diabetes are not fully effective and frequently accompanied by many negative effects. Therefore, novel ways to prevent insulin resistance and type 2 diabetes are urgently needed. The roots of Scutellaria radix are commonly used in traditional Chinese medicines for prevention and treatment of type 2 diabetes, atherosclerosis, hypertension, hyperlipidemia, dysentery, and other respiratory disorders. Baicalin and baicalein are the major and active ingredient extracts from Scutellaria baicalensis. METHODS: A comprehensive and systematic review of literature on baicalin and baicalein was carried out. RESULTS: Emerging evidence indicated that baicalin and baicalein possessed hepatoprotective, anti-oxidative, anti-dyslipidemic, anti-lipogenic, anti-obese, anti-inflammatory, and anti-diabetic effects, being effective for treating obesity, insulin resistance, non-alcoholic fatty liver, and dyslipidemia. Besides, baicalin and baicalein are almost non-toxic to epithelial, peripheral, and myeloid cells. CONCLUSION: The purpose of this study is to focus on the therapeutic applications and accompanying molecular mechanisms of baicalin and baicalein against hyperglycemia, insulin resistance, type 2 diabetes, hyperlipidemia, obesity, and non-alcoholic fatty liver, and trying to establish a novel anti-obese and anti-diabetic strategy.

San-Huang-Tang protects obesity/diabetes induced NAFLD by upregulating PGC-1α/PEPCK signaling in obese and galr1 knockout mice models.

ETHNOPHARMACOLOGICAL RELEVANCE: San-Huang-Tang (ST), a classic prescription, has been clinically used to cure diabetes and diabetes-associated metabolic disorders. Established studies have reported that ST can alleviate inflammation, obesity, hyperglycemia and insulin resistance. AIM OF THE STUDY: To the best of our knowledge, here, we reported for the first time the underlying mechanistic therapeutic efficacy of the ST against nonalcoholic fatty liver disease (NAFLD) in high-fat induced obese and galr1-deficient diabetic mice. MATERIALS AND METHODS: The obese and galr1-deficient mice were treated with ST at a dose of 10 g/kg every day for three weeks. Then food intake, body weight and insulin resistance indexes were measured. Western blotting, qRT-PCR, and plasma biochemical analyses were applied. RESULTS: ST reduced food intake, body weight, blood glucose level and insulin resistance, improved glucose tolerance in obese and galr1-deficient mice. Mechanistically, we confirmed that ST protected against NAFLD through activation of PGC-1α and its downstream signaling pathways as shown by the attenuated hepatic adipogenesis and lipid accumulation, increased hepatic fatty acid oxidation, regulated plasma lipid parameters, and increased energy expenditure and metabolic function in fat and muscle. CONCLUSIONS: Reduction in food intake produced by ST may contribute to the observed metabolic effects. Our findings strongly suggest that ST might be a potential novel therapeutic drug against obesity/diabetes-induced NAFLD and other metabolic disorders.

Baicalin ameliorates hepatic insulin resistance and gluconeogenic activity through inhibition of p38 MAPK/PGC-1α pathway.

BACKGROUND: Although the results of our and other studies show that baicalin can enhance glucose uptake and insulin sensitivity in skeletal muscle and adipocytes of mice, the specific metabolic contribution of baicalin on hepatic insulin resistance and gluconeogenic activity is still unclear. PURPOSE: The aim of this study is to investigate whether baicalin is involved in regulation of hepatic insulin resistance and gluconeogenic activity and its underlying mechanisms. STUDY DESIGN/METHODS: In the present study, high-fat diet-induced obese mice were given 50 mg/kg baicalin intraperitoneally (i.p.) once a day for 21 consecutive days, and hepatocytes were treated with baicalin (100 µM) or metformin (100 µM) in the presence of glucagon (200 nM) for 12 h. Then insulin resistance indexes and genes related to gluconeogenesis were examined in liver tissues. RESULTS: The present findings showed that baicalin decreased body weight, HOMA-IR, and alleviated high fat diet-induced glucose intolerance, hyperglycemia and insulin resistance in diet-induced obese mice. Furthermore, baicalin markedly suppressed p-p38 MAPK, p-CREB, FoxO1, PGC-1α, PEPCK and G6Pase expression in liver of obese mice and hepatocytes. Moreover, inhibition of gluconeogenic genes by baicalin was also strengthened by p38MAPK inhibitor in hepatocytes. CONCLUSION: Baicalin suppressed expression of PGC-1α and gluconeogenic genes, and reduced glucose production in high-fat diet-induced obese mice. Baicalin ameliorated hepatic insulin resistance and gluconeogenic activity mainly through inhibition of p38 MAPK/PGC-1α signal pathway. This study provides a possibility of using baicalin to treat hyperglycemia and hepatic insulin resistance in clinic.

MicroRNAs in the Progress of Diabetic Nephropathy: A Systematic Review and Meta-Analysis.

BACKGROUND: We conducted a systematic review and meta-analysis of existing literature to evaluate the different outcomes of microRNAs (miRNAs) in diabetic nephropathy (DN), including urinary albumin excretion rates, urinary albumin creatinine rates, glomerular filtration rate, HbAc1, and creatinine. METHODS: Electronic databases including PUBMED, MEDLINE, and EMBASE were searched for eligible publications to July 2018. The following comparisons between treatment groups were included: normal group versus DN group; control group versus micro/macroalbuminuria group. RESULTS: Twelve eligible studies that included 2500 participants were finally recruited in this meta-analysis. Fifteen miRNAs (miRNA-21, miRNA-181b, miRNA-194, miRNA-30, miRNA-215, and others) were upregulated whereas seven miRNAs (miRNA-26a, miRNA-126, miRNA-424, miRNA-574-3p, miR-223, miR-155, and miR-192) were downregulated in the DN group compared with control groups. The miR-133b, miR-342, miR-30, miR-192, miR-194, and miR-215 were significantly correlated in urinary albumin excretion rates (r=0.33, 95% CI= 0.26-0.39). miR-192, miR-217, miR-15b, miR-34a, and miR-636 were correlated with urinary albumin creatinine rates (r=0.69; 95% CI=0.12-0.92), while miR-133b, miR-345, miR-33, miR-326, miR-574-3p, miR-126, miR-217, miR-15b, miR-34a, and miR-636 were significantly correlated with HbAc1 (r =0.23, 95% CI = 0.15-0.31). There were twelve miRNAs that were closely related to the glomerular filtration rate (r=0.28, 95% CI =0.21-0.34). Creatinine (r=0.33, 95% CI = 0.22-0.40) was significantly different between normal and DN groups. CONCLUSIONS: The meta-analysis acquired the correlations between miRNAs and outcomes including UAER, UACR, eGFR, HbAc1, and creatinine in DN. It suggested that miRNAs may participate in the pathogenesis of DN process.

Treatment with celastrol protects against obesity through suppression of galanin-induced fat intake and activation of PGC-1α/GLUT4 axis-mediated glucose consumption.

Overweight and obesity may cause several metabolic complications, including type 2 diabetes mellitus and hyperlipidemia. Despite years of progress in medicine, there are no highly effective pharmacological treatments for obesity. The natural compound celastrol, a pentacyclic triterpene extracted from the roots of Tripterygium Wilfordi (thunder god vine) plant, exerts various bioactivities including anti-diabetic and anti-obese effects. Although celastrol could decrease food intake and obesity, the detailed mechanism for celastrol is still unclear as yet. Herein, we intended to determine the effect of celastrol on obesity and the underlying mechanisms. In the present study, diet-induced obese mice were treated with 100 µg/kg/d celastrol for the last 21 days, and 3T3-L1 cells were treated with celastrol for 6 h. The present findings showed that celastrol suppresses fat intake, and leads to weight loss by inhibiting galanin and its receptor expression in the hypothalamus of mice fed a high-fat diet. More importantly, in addition to these direct anti-obesity activities, celastrol augmented the PGC-1α and GLUT4 expression in adipocytes and skeletal muscles to increase glucose uptake through AKT and P38 MAPK activation. Celastrol also inhibited gluconeogenic activity through a CREB/PGC-1α pathway. In conclusion, the weight-lowering effects of celastrol are driven by decreased galanin-induced food consumption. Thus, this study contributes to our understanding of the anti-obese role of celastrol, and provides a possibility of using celastrol to treat obesity in clinic.

Beneficial effect of baicalin on insulin sensitivity in adipocytes of diet-induced obese mice.

AIMS: Although baicalin has been shown to increase glucose uptake and insulin sensitivity in skeletal muscle of mice, there is no literature available about the effect of baicalin on insulin sensitivity in adipocytes of diet-induced obese mice. METHODS: In the present study, diet-induced obese mice were given 50 mg/kg baicalin intraperitoneally (i.p.) once a day for 21 days, and 3T3-L1 cells were treated with 100, 200, 400 µM baicalin for 3 h. Then insulin resistance indexes and insulin signal protein levels were examined to elucidate whether baicalin increased glucose uptake and GLUT4 translocation in adipocytes of diet-induced obese mice. RESULTS: The present findings showed that administration of baicalin decreased food intake, body weight, HOMA-IR and p-p38 MAPK and pERK levels, but enhanced pAKT and PGC-1α contents, as well as GLUT4 mRNA, PGC-1α mRNA expression in adipocytes, and reversed high fat diet-induced glucose intolerance, hyperglycemia and insulin resistance in diet-induced obese mice. Moreover, baicalin treatment increased GLUT4 concentration in plasma membranes of adipocytes. CONCLUSIONS: These data demonstrated that baicalin accelerated GLUT4 translocation from intracellular membrane compartments to plasma membranes in adipocytes. Baicalin plays a significant role in elevation of glucose uptake and insulin sensitivity to promote glucose clearance.

Melatonin treatment of pre-veraison grape berries to increase size and synchronicity of berries and modify wine aroma components.

A comprehensive investigation was carried out to determine the effect of exogenous melatonin treatment of pre-veraison grapes on grape berries and its wines. Two melatonin treatments of pre-veraison grape berries increased the weight of the berries by approximately 6.6%. Meanwhile, this melatonin treatment could be beneficial in the reduction of underripe and overripe fruits and in enhancing the synchronicity of the berries. In addition, there were significant differences in the volatile compound composition between the wine produced from the melatonin-treated berries and the wines made from untreated berries. The wine from melatonin-treated pre-veraison grape berries had stronger fruity, spicy, and sweet sensory properties, compared to the wines made from untreated berries. Prolonging the treatment through repeated applications can enhance these effects and under different seasonal conditions, more pronounced effects on the grape quality and wine properties can be observed.

Intracerebroventricular administration of galanin antagonist sustains insulin resistance in adipocytes of type 2 diabetic trained rats.

The aim of this study is to investigate whether galanin (GAL) central receptors are involved in regulation of insulin resistance. To test it, a GAL antagonist, M35 was intracerebroventricularly administrated in trained type 2 diabetic rats. The euglycemic-hyperinsulinemic clamp test was conducted for an index of glucose infusion rates. The epididymal fat pads were processed for determination of glucose uptake and Glucose Transporter 4 (GLUT4) amounts. The Gal mRNA expression levels in hypothalamus were quantitatively assessed too. We found an inhibitory effect of M35 on glucose uptake into adipocytes, Gal mRNA expression levels in hypothalamus, glucose infusion rates in the clamp test and GLUT4 concentration in plasma membranes and total cell membranes of adipocytes. The ratios of GLUT4 contents of the former to the latter in M35 groups were lower. These results suggest a facilitating role for GAL on GLUT4 translocation and insulin sensitivity via its central receptors in rats.

Varietal differences among the phenolic profiles and antioxidant properties of four cultivars of spine grape (Vitis davidii Foex) in Chongyi County (China).

Spine grape (Vitis davidii Foex) is an important wild plant species in South China. To provide sufficient experimental evidence for the strong antioxidant activity of spine grapes, four cultivars from Chongyi County, China, including three red varieties (Junzi #1, Junzi #2, and Liantang) and one white variety (Baiyu) were evaluated. The Junzi #1 had the highest phenolic content (total phenolic, flavonoids, flavanols, and anthocyanins) and the strongest antioxidant capacity (DPPH radical-scavenging capacity, cupric-reducing capacity and hydroxyl radical-scavenging activity) among the four varieties. HPLC analysis of spine grapes revealed that the (+)-catechin was the most abundant phenolics and the hydroxycinnamic acids were the major phenolic acids in the four varieties. Hierarchical cluster analysis showed that the Junzi #1 belongs to the group with high phenolic content and strong antioxidant power. The results suggest the Junzi #1 has the best health promoting properties, and the higher utilization value and potential for development.

Free-radical scavenging properties and reducing power of grape cane extracts from 11 selected grape cultivars widely grown in China.

Total phenolic contents (TPC), total flavonoid contents (TFC), related antioxidative and antiradical capabilities of grape cane extracts from 11 varieties (five V. vinifera cultivars and six Chinese wild grapes) widely grown in China were evaluated. Antioxidant properties were determined as DPPH and ABTS radical-scavenging abilities, superoxide anion and hydroxyl radical and hydrogen peroxide scavenging assays, as well as reducing power. Phenolic profiles of the extracts were characterized by using high-performance liquid chromatography (HPLC) techniques. All extracts exhibited strong antioxidant and effective free radical inhibition activities (EC(50) values), which generally correlated negatively with TPC (r = -0.804 to -0.918) and TFC (r = -0.749 to -0.888). In comparison with gallic acid, Trolox and tert-butylhydroquinone (positive controls), most grape cane extracts showed more efficient scavenging effects toward different reactive oxygen species. HPLC analysis revealed the presence of (+)-catechin, (-)-epicatechin, and trans-resveratrol as major phenolic components in the extracts. These results suggest that grape cane extracts may serve as a potential source of natural antioxidant for food and pharmaceutical application.

Nucleotide diversity patterns of local adaptation at drought-related candidate genes in wild tomatoes.

We surveyed nucleotide diversity at two candidate genes LeNCED1 and pLC30-15, involved in an ABA (abscisic acid) signalling pathway, in two closely related tomato species Solanum peruvianum and Solanum chilense. Our six population samples (three for each species) cover a range of mesic to very dry habitats. The ABA pathway plays an important role in the plants' response to drought stress. LeNCED1 is an upstream gene involved in ABA biosynthesis, and pLC30-15 is a dehydrin gene positioned downstream in the pathway. The two genes show very different patterns of nucleotide variation. LeNCED1 exhibits very low nucleotide diversity relative to the eight neutral reference loci that were previously surveyed in these populations. This suggests that strong purifying selection has been acting on this gene. In contrast, pLC30-15 exhibits higher levels of nucleotide diversity and, in particular in S. chilense, higher genetic differentiation between populations than the reference loci, which is indicative of local adaptation. In the more drought-tolerant species S. chilense, one population (from Quicacha) shows a significant haplotype structure, which appears to be the result of positive (diversifying) selection.