Influence of ursodeoxycholic acid on blood glucose, insulin and GLP-1 in rats with liver fibrosis induced by bile duct ligation

Ursodeoxycholic and chenodeoxycholic bile acids attenuate systemic and liver inflammation induced by lipopolysaccharide in rats

Bacterial lipopolysaccharide (LPS) induces general inflammation, by activating pathways involving cytokine production, blood coagulation, complement system activation, and acute phase protein release. The key cellular players are leukocytes and endothelial cells, that lead to tissue injury and organ failure. The aim of this study was to explore the anti-inflammatory, antioxidant, and cytoprotective properties of two bile acids, ursodeoxycholic acid (UDCA) and chenodeoxycholic acid (CDCA) in LPS-induced endotoxemia in rats. The experiment involved six distinct groups of Wistar rats, each subjected to different pretreatment conditions: control and LPS groups were pretreated with propylene glycol, as a bile acid solvent, while the other groups were pretreated with UDCA or CDCA for 10 days followed by an LPS injection on day 10. The results showed that both UDCA and CDCA reduced the production of pro-inflammatory cytokines: TNF-α, GM-CSF, IL-2, IFNγ, IL-6, and IL-1β and expression of nuclear factor-κB (NF-κB) induced by LPS. In addition, pretreatment with these bile acids showed a positive impact on lipid profiles, a decrease in ICAM levels, an increase in antioxidant activity (SOD, |CAT, GSH), and a decrease in prooxidant markers (H2O2 and O2-). Furthermore, both bile acids alleviated LPS-induced liver injury. While UDCA and CDCA pretreatment attenuated homocysteine levels in LPS-treated rats, only UDCA pretreatment showed reductions in other serum biochemical markers, including creatine kinase, lactate dehydrogenase, and high-sensitivity troponin I. It can be concluded that both, UDCA and CDCA, although exerted slightly different effects, can prevent the inflammatory responses induced by LPS, improve oxidative stress status, and attenuate LPS-induced liver injury.

Bile acids: Can the position of hydroxyl substitution influence antidiabetic potency?

Numerous analogous compounds exist in natural products, exhibiting subtle structural variations that nonetheless result in distinct biological activities. Hyodeoxycholic acid (HDCA), ursodeoxycholic acid (UDCA), and deoxycholic acid (DCA) are analogues belonging to the steroids, and related studies have demonstrated that all three possess antidiabetic effects in reducing hyperglycemia. Diabetes mellitus is a metabolic disease with high morbidity and mortality in recent years. A thorough exploration of the mechanisms underlying compounds with potential antidiabetic properties serves as an essential prerequisite for subsequent research endeavors. However, the mechanism of action regarding them has not been fully verified, and the present study identified one of the antidiabetic mechanisms of action of bile acid analogs at the protein and molecular levels. The results suggested that structural differences due to differences in the position of the hydroxyl substituent alter the antidiabetic capacity. The application of machine learning methods for pharmacokinetic prediction contributes to a better understanding of the nature and in vivo behavior of bile acid analogs. This study endeavors to establish a basic reference and experimental foundation to contribute to the ongoing exploration of the potential role of bile acid compounds in antidiabetic mechanisms.

Relationships and Mendelian Randomization of Gut Microbe-Derived Metabolites with Metabolic Syndrome Traits in the METSIM Cohort

The role of gut microbe-derived metabolites in the development of metabolic syndrome (MetS) remains unclear. This study aimed to evaluate the associations of gut microbe-derived metabolites and MetS traits in the cross-sectional Metabolic Syndrome In Men (METSIM) study. The sample included 10,194 randomly related men (age 57.65 ± 7.12 years) from Eastern Finland. Levels of 35 metabolites were tested for associations with 13 MetS traits using lasso and stepwise regression. Significant associations were observed between multiple MetS traits and 32 metabolites, three of which exhibited particularly robust associations. N-acetyltryptophan was positively associated with Homeostatic Model Assessment for Insulin Resistant (HOMA-IR) (β = 0.02, p = 0.033), body mass index (BMI) (β = 0.025, p = 1.3 × 10-16), low-density lipoprotein cholesterol (LDL-C) (β = 0.034, p = 5.8 × 10-10), triglyceride (0.087, p = 1.3 × 10-16), systolic (β = 0.012, p = 2.5 × 10-6) and diastolic blood pressure (β = 0.011, p = 3.4 × 10-6). In addition, 3-(4-hydroxyphenyl) lactate yielded the strongest positive associations among all metabolites, for example, with HOMA-IR (β = 0.23, p = 4.4 × 10-33), and BMI (β = 0.097, p = 5.1 × 10-52). By comparison, 3-aminoisobutyrate was inversely associated with HOMA-IR (β = -0.19, p = 3.8 × 10-51) and triglycerides (β = -0.12, p = 5.9 × 10-36). Mendelian randomization analyses did not provide evidence that the observed associations with these three metabolites represented causal relationships. We identified significant associations between several gut microbiota-derived metabolites and MetS traits, consistent with the notion that gut microbes influence metabolic homeostasis, beyond traditional risk factors.

Review on chronic metabolic diseases surrounding bile acids and gut microbiota: What we have explored so far

Bile acid, the final product of cholesterol breakdown, functions as a complex regulator and signaling factor in human metabolism. Chronic metabolic diseases pose significant medical challenges. Growing research underscores bile acids' capacity to enhance metabolism via diverse pathways, regulating disorders and offering treatment potential. Numerous bile-acid-triggered pathways have become treatment targets. This review outlines bile acid synthesis, its role as a signal in chronic metabolic diseases, and highlights its interaction with gut microbiota in different metabolic conditions. Exploring host-bacteria-bile acid links emerges as a valuable future research direction with clinical implications.

Impact of bariatric surgery on glucose and lipid metabolism and liver and kidney function in food-induced obese diabetic rats

BACKGROUND

Obesity usually causes diabetes mellitus (DM) and is a serious danger to human health. Type 2 DM (T2DM) mostly occurs along with obesity. Foodborne obesity-induced DM is caused by an excessive long-term diet and surplus energy. Bariatric surgery can improve the symptoms of T2DM in some obese patients. But different types of bariatric surgery may have different effects.

AIM

To investigate the effect of bariatric surgery on glucose and lipid metabolism and liver and kidney function in rats.

METHODS

Male Sprague-Dawley rats aged 6-8 wk underwent Roux-en-Y gastric bypass surgery (RYGB), sleeve gastrectomy (SG), or gastric banding (GB). Glucose and insulin tolerance tests, analyses of biochemical parameters, histological examination, western blot, and quantitative real-time polymerase chain reaction were conducted.

RESULTS

In comparison to the sham operation group, the RYGB, SG, and GB groups had decreased body weight and food intake, reduced glucose intolerance and insulin insensitivity, downregulated biochemical parameters, alleviated morphological changes in the liver and kidneys, and decreased levels of protein kinase C β/ P66shc. The effect in the RYGB group was better than that in the SG and GB groups.

CONCLUSION

These results suggest that RYGB, SG and GB may be helpful for the treatment of foodborne obesity-induced DM.