Proanthocyanidins from Chinese bayberry leaves reduce obesity and associated metabolic disorders in high-fat diet-induced obese mice through a combination of AMPK activation and an alteration in gut microbiota

A decade review on phytochemistry and pharmacological activities of Cynomorium songaricum Rupr.: Insights into metabolic syndrome

BACKGROUND

Cynomorium songaricum Rupr. (CSR), a perennial herb with a rich history in traditional medicine, has demonstrated therapeutic potential against metabolic syndrome (MetS) through its active compounds, including proanthocyanidins, polysaccharides, and triterpenoids. MetS, a global health concern, encompasses interlinked conditions such as obesity, type 2 diabetes mellitus (T2DM), and inflammation. This review synthesizes recent findings on CSR's pharmacological and phytochemical properties, focusing on its role in ameliorating MetS.

METHODS

Following Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines, relevant studies were retrieved from PubMed, Web of Science, and CNKI databases up to December 2024. Keywords included "Cynomorium Songaricum Rupr.", "Cynomorii Herba", "Suoyang", "Suo Yang", "Metabolic syndrome", "Proanthocyanidins", "Polysaccharides" and "Triterpenoids" and their combinations. Inclusion criteria emphasized studies exploring CSR's impact on MetS, while duplicate, low-quality studies and studies not written in Chinese, English, or unrelated were excluded.

RESULTS

A total of 92 studies were analyzed, revealing that CSR's active components exhibit multi-target effects. Proanthocyanidins reduce glucose absorption and oxidative stress, polysaccharides enhance insulin sensitivity and gut microbiota composition, and triterpenoids mitigate obesity and mitochondria damage. These mechanisms collectively contribute to the beneficial effects of CSR against MetS.

CONCLUSION

CSR presents a promising natural therapy for MetS, utilizing its pharmacologically active compounds to address core metabolic dysfunctions. Future studies should focus on clinical validation and safety assessments to facilitate CSR's integration into modern therapeutic regimens.

Therapeutic Potential of Cranberry Proanthocyanidins in Addressing the Pathophysiology of Metabolic Syndrome: A Scrutiny of Select Mechanisms of Action

Metabolic syndrome (MetS) constitutes a spectrum of interconnected conditions comprising obesity, dyslipidemia, hypertension, and insulin resistance (IR). While a singular, all-encompassing treatment for MetS remains elusive, an integrative approach involving tailored lifestyle modifications and emerging functional food therapies holds promise in preventing its multifaceted manifestations. Our main objective was to scrutinize the efficacy of cranberry proanthocyanidins (PAC, 200 mg/kg/day for 12 weeks) in mitigating MetS pathophysiology in male mice subjected to standard Chow or high-fat/high-fructose (HFHF) diets while unravelling intricate mechanisms. The administration of PAC, in conjunction with an HFHF diet, significantly averted obesity, evidenced by reductions in body weight, adiposity across various fat depots, and adipocyte hypertrophy. Similarly, PAC prevented HFHF-induced hyperglycemia and hyperinsulinemia while also lessening IR. Furthermore, PAC proved effective in alleviating key risk factors associated with cardiovascular diseases by diminishing plasma saturated fatty acids, as well as levels of triglycerides, cholesterol, and non-HDL-C levels. The rise in adiponectin and drop in circulating levels of inflammatory markers showcased PAC's protective role against inflammation. To better clarify the mechanisms behind PAC actions, gut-liver axis parameters were examined, showing significant enhancements in gut microbiota composition, microbiota-derived metabolites, and marked reductions in intestinal and hepatic inflammation, liver steatosis, and key biomarkers associated with endoplasmic reticulum (ER) stress and lipid metabolism. This study enhances our understanding of the complex mechanisms underlying the development of MetS and provides valuable insights into how PAC may alleviate cardiometabolic dysfunction in HFHF mice.

Hericium erinaceus Protein Alleviates High-Fat Diet-Induced Hepatic Lipid Accumulation and Oxidative Stress In Vivo

Dietary interventions with food-derived natural products have emerged as a promising strategy to alleviate obesity. This study aims to investigate the anti-obesity effect of Hericium erinaceus protein (HEP) and its underlying mechanism. Our results demonstrated that HEP exhibited excellent radical scavenging activity in vitro. In vivo, HEP intervention reduced pancreatic lipase activity in the intestine and enhanced fat excretion, thereby inhibiting the absorption of dietary fats. Meanwhile, HEP ameliorated the body weight and organ indexes, dyslipidemia, insulin resistance, hepatic steatosis, and liver oxidative stress injuries in obese mice. The results of real-time PCR (qRT-PCR) and Western blot analyses indicated that HEP upregulated the expression of peroxisome proliferator-activated receptor α (PPARα), subsequently upregulated the expression of liver fatty acid oxidation-related genes (lipoprotein lipase (LPL), carnitine palmitoyltransferase 1a (CPT-1a), and acyl-CoA oxidase 1 (ACOX1)) and downregulated the expression of lipogenesis-related genes (sterol regulatory element-binding protein-1c (SREBP-1c), stearoyl-coenzyme A desaturase 1 (SCD-1), and fatty acid synthase (FASN)), thereby ameliorating lipid metabolism disorders. Therefore, these findings demonstrated that HEP exerted protective effects on lipid metabolism disorders by activating the PPARα pathway, indicating its potential as a dietary supplement for the prevention and amelioration of obesity.

Gut-Derived Ursodeoxycholic Acid from Saponins of Quinoa Regulated Colitis via Inhibiting the TLR4/NF-κB Pathway

Alteration of the gut microbiota and its metabolites plays a key role in the development of inflammatory bowel disease (IBD). Here, we investigated the mechanism of saponins, a byproduct from quinoa (SQ) processing, in regulating IBD. SQ ameliorated gut microbiota dysbiosis revealed by 16S rRNA sequencing and improved colonic antioxidant activities and barrier integrity in dextran sulfate sodium (DSS)-treated mice. Broad-spectrum antibiotics further proved that the gut-protective effects of SQ were mediated by gut microbiota. Next, fecal microbiota transplantation (FMT) of SQ-induced gut microbiota/metabolites to inoculate DSS-treated mice alleviated colitis significantly. Untargeted metabolomics and lipidomics revealed that ursodeoxycholic acid (UDCA) was enriched as a microbial metabolite after SQ supplementation. UDCA was then found to attenuate DSS-induced colitis in vivo by targeting the TLR4/NF-κB pathway, which was also verified in a Caco-2 cell model treated with a TLR4 agonist/antagonist. Overall, our findings established that gut microbiota-UDCA-TLR4/NF-κB signaling plays a key role in mediating the protective effects of SQ.

Chitooligosaccharide-epigallocatechin gallate conjugate ameliorates lipid accumulation and promotes browning of white adipose tissue in high fat diet fed rats

The prevalence of obesity has increased progressively worldwide. Obesity is characterized by excessive accumulation of fat in adipose tissues, leading to metabolic impairment. The anti-obese effects of chitooligosaccharide (COS) and epigallocatechin-3-gallate (EGCG) have been extensively clarified. This study aimed to investigate the effects and potential mechanisms of the COS-EGCG conjugate (CE) on anti-obesity, specifically by alleviating lipid accumulation and promoting the browning of white adipose tissue (WAT) in obese rats. Obesity as a consequence of a high-fat diet (HFD) was induced in male Wistar rats. The HFD was given for 16 weeks and the rats were then randomly subdivided into five groups namely: vehicle (control group), HFD plus CE at 150 mg/kg/day, HFD plus CE at 600 mg/kg/day, HFD plus COS at 600 mg/kg/day, and HFD plus atorvastatin at 10 mg/kg/day for 4 weeks. CE could reduce body weight, improve serum lipid profiles, and promote lipid metabolism via activation of AMP-activated protein kinase (AMPK) in WAT and enhance the processes of WAT browning by activating sirtuin 1 (Sirt 1), peroxisome proliferator-activated receptor-gamma coactivator (PGC1-α), and uncoupling the protein 1 (UCP1) signaling pathway. CE reduced obesity and promoted WAT browning in HFD-fed rats. Therefore, CE might be a new therapy for metabolic syndrome and obesity.

Revisiting dietary proanthocyanidins on blood glucose homeostasis from a multi-scale structural perspective

Multi-dimensional studies have consistently indicated the benefits of dietary proanthocyanidins on blood glucose homeostasis through consumption of them from fruits, cereals and nuts. Proanthocyanidins from various sources possess different structures, but even the minor variations in structures influence their regulation on blood glucose, including the degree of polymerization, galloacylation at C3, number of hydroxyl groups in B ring and linkage type. Therefore, this Review details the role of three types of proanthocyanidins (procyanidins, prodelphinidins and propelargonidins) in blood glucose control and their underlying mechanisms, and various structural features contribute to. Due to the extremely low bioavailability, proanthocyanidins mainly ameliorate high blood glucose by luminal effects: inhibit enzyme activities, improve the structure of gut microbiota, and protect the intestinal barrier function. A few absorbed proanthocyanidins exert insulin-like effects on targeted organs. Prodelphinidin gallates exhibit greater hypoglycemic activities than others, due to their galloacylation at C3 and high amounts of hydroxyl groups in B ring. Because of different action pathways, comprehensive consideration on the degree of polymerization, linkage type and density of hydroxyl groups was required. Further understanding of these relationships can concrete diet therapeutic opportunities for proanthocyanidins.

Bound Polyphenols of Oat Bran Released by Gut Microbiota Mitigate High Fat Diet-Induced Oxidative Stress and Strengthen the Gut Barrier via the Colonic ROS/Akt/Nrf2 Pathway

Whole-grain foods are rich in bound polyphenols (BPs) whose health benefits were largely underestimated compared with free polyphenols. We first found that DFBP (dietary fiber with BPs from oat bran) exhibited stronger colonic antioxidant activities than DF. 16S rRNA sequencing showed that DFBP selectively changed gut microbial composition, which reciprocally released BPs from DFBP. Released polyphenols from DFBP reduced excessive colonic ROS and exhibited colonic antioxidant activities via the ROS/Akt/Nrf2 pathway revealed by transcriptome and western blot analysis. Colonic antioxidant activities of DFBP mediated by gut microbiota were next proven by treating mice with broad-spectrum antibiotics. Next, Clostridium butyricum, as a distinguished bacterium after DFBP intervention, improved colonic antioxidant capacities synergistically with DFBP in HFD-fed mice. This was explained by the upregulated mRNA expression of esterase, and cellulase of Clostridium butyricum participated in releasing BPs. Our results would provide a solid basis for explaining the health benefits of whole grains.

Oat Dietary Fiber Delays the Progression of Chronic Kidney Disease in Mice by Modulating the Gut Microbiota and Reducing Uremic Toxin Levels

Chronic kidney disease (CKD) has emerged as a significant public health concern. In this article, we investigated the mechanism of oat dietary fiber in regulating CKD. Our findings indicated that the gut microbiota of CKD patients promoted gut microbiota dysbiosis and kidney injury in CKD mice. Intervention with oat-resistant starch prepared by ultrasonic combined enzymatic hydrolysis (ORSU) and oat β-glucan with a molecular weight of 5 × 104 Da (OBGM) elevated the levels of short-chain fatty acids (SCFAs) and regulated gut dysbiosis in the gut-humanized CKD mice. ORSU and OBGM also reduced CKD-related uremic toxins such as creatinine, indoxyl sulfate (IS), and p-cresol sulfate (PCS) levels; reinforced the intestinal barrier function of the gut-humanized CKD mice; and mitigated renal inflammation and fibrosis via the NF-κB/TGF-β pathway. Therefore, ORSU and OBGM might delay the progression of CKD by modulating the gut microbiota to reduce uremic toxins levels. Our results explain the mechanism of oat dietary fiber aimed at mitigating CKD.

The effects of inulin on solubilizing and improving anti-obesity activity of high polymerization persimmon tannin

High polymerization persimmon tannin has been reported to have lipid-lowering effects. Unfortunately, the poor solubility restricts its application. This research aimed to investigate the effect and mechanism of inulin on solubilizing of persimmon tannin. Furthermore, we examined whether the addition of inulin would affect the attenuated obesity effect of persimmon tannin. Transmission electron microscope (TEM), Isothermal titration calorimetry (ITC) and Fourier transform infrared spectroscopy (FT-IR) results demonstrated that inulin formed a gel-like network structure, which enabled the encapsulation of persimmon tannin through hydrophobic and hydrogen bond interactions, thereby inhibiting the self-aggregation of persimmon tannin. The turbidity of the persimmon tannin solution decreased by 56.2 %, while the polyphenol content in the supernatant increased by 60.0 %. Furthermore, biochemical analysis and 16s rRNA gene sequencing technology demonstrated that persimmon tannin had a significant anti-obesity effect and improved intestinal health in HFD-fed mice. Moreover, inulin was found to have a positive effect on enhancing the health benefits of persimmon tannin, including improving hepatic steatosis and gut microbiota dysbiosis. it enhanced the abundance of beneficial core microbes while decreasing the abundance of harmful bacteria. Our findings expand the applications of persimmon tannin in the food and medical sectors.

Chinese bayberry (Myrica rubra Sieb. et Zucc.) leaves proanthocyanidins inhibit intestinal glucose transport in human Caco-2 cells

Background: The hypoglycemic effects of Chinese bayberry leaves proanthocyanidins (BLPs) have been demonstrated. It is unclear, nevertheless, whether BLPs reduced postprandial blood glucose levels by regulating glucose uptake and glucose transport. Method: This study investigated the effect of BLPs (25, 50, and 100 μg/mL) on glucose uptake and glucose transport in human intestinal epithelial cells (Caco-2 cells). The uptake of 2-Deoxy-2-[(7-nitro-2,1,3-benzoxadiazol-4-yl) amino]-D-glucose (2-NBDG) and disaccharidases activity in Caco-2 cells were measured. The glucose transport ability across the cell membrane was determined using the established Caco-2 monolayer model. The transcript and protein levels of key glucose transporters were analyzed using real-time quantitative polymerase chain reaction (RT-qPCR) and western blotting, respectively. Results: The results showed that BLPs significantly decreased glucose uptake and disaccharidases activity (p < 0.05). Otherwise, BLPs treatment obviously inhibited glucose transport across the Caco-2 monolayer in both simulated-fast (5 mM glucose) and simulated-fed (25 mM glucose) conditions. It was attributed to the suppression of glucose transporter2 (GLUT2) and sodium-dependent glucose cotransporter 1 (SGLT1) by BLPs. BLPs were found to significantly downregulated the transcript level and protein expression of glucose transporters (p < 0.05). Meanwhile, the mRNA expression of phospholipase C (PLC) and protein kinase C (PKC) involved in the signaling pathway associated with glucose transport were decreased by BLPs. Conclusion: These results suggested that BLPs inhibited intestinal glucose transport via inhibiting the expression of glucose transporters. It indicated that BLPs could be potentially used as a functional food in the diet to modulate postprandial hyperglycemia.

Proanthocyanidins-Based Synbiotics as a Novel Strategy for Nonalcoholic Fatty Liver Disease (NAFLD) Risk Reduction

Nonalcoholic fatty liver disease (NAFLD), the most common liver disease worldwide, is a spectrum of liver abnormalities ranging from steatosis to nonalcoholic steatohepatitis (NASH) characterized by excessive lipid accumulation. The prevalence of NAFLD is predicted to increase rapidly, demanding novel approaches to reduce the global NAFLD burden. Flavonoids, the most abundant dietary polyphenols, can reduce the risk of NAFLD. The majority of dietary flavonoids are proanthocyanidins (PACs), which are oligomers and polymers of the flavonoid sub-group flavan-3-ols. The efficacy of PAC in reducing the NAFLD risk can be significantly hindered by low bioavailability. The development of synbiotics by combining PAC with probiotics may increase effectiveness against NAFLD by biotransforming PAC into bioavailable metabolites. PAC and probiotic bacteria are capable of mitigating steatosis primarily through suppressing de novo lipogenesis and promoting fatty acid β-oxidation. PAC and probiotic bacteria can reduce the progression of steatosis to NASH mainly through ameliorating hepatic damage and inflammation induced by hepatic oxidative stress, endoplasmic reticulum stress, and gut microbiota dysbiosis. Synbiotics of PAC are superior in reducing the risk of NAFLD compared to independent administration of PAC and probiotics. The development of PAC-based synbiotics can be a novel strategy to mitigate the increasing incidence of NAFLD.

Natural compounds against nonalcoholic fatty liver disease: A review on the involvement of the LKB1/AMPK signaling pathway

Although various therapeutic approaches are used to manage nonalcoholic fatty liver disease (NAFLD), the best approach to NAFLD management is unclear. NAFLD is a liver disorder associated with obesity, metabolic syndrome, and diabetes mellitus. NAFLD progression can lead to cirrhosis and end-stage liver disease. Hepatic kinase B1 (LKB1) is an upstream kinase of 5'-adenosine monophosphate-activated protein kinase (AMPK), a crucial regulator in hepatic lipid metabolism. Activation of LKB1/AMPK inhibits fatty acid synthesis, increases mitochondrial β-oxidation, decreases the expression of genes encoding lipogenic enzymes, improves nonalcoholic steatohepatitis, and suppresses NAFLD progression. One potential opening for new and safe chemicals that can tackle the NAFLD pathogenesis through the LKB1-AMPK pathway includes natural bioactive compounds. Accordingly, we summarized in vitro and in vivo studies regarding the effect of natural bioactive compounds such as a few members of the polyphenols, terpenoids, alkaloids, and some natural extracts on NAFLD through the LKB1/AMPK signaling pathway. This manuscript may shed light on the way to finding a new therapeutic agent for NAFLD management.

Whey and Buttermilk-Based Formulas Modulate Gut Microbiota in Mice with Antibiotic-Induced Dysbiosis

SCOPE

Diet is one of the main factors that modifies intestinal microbiota composition. The search for foods that can reverse situations of intestinal dysbiosis such as that induced by antibiotics is of great interest. Buttermilk and whey are the main by-products produced by the dairy industry containing bioactive compounds. The aim of this study is to investigate the ability of whey and buttermilk-based formulas supplemented with lactoferrin and milk fat globule membrane (MFGM) to modulate the effects of clindamycin on mouse intestinal microbiota.

METHODS AND RESULTS

Male C57BL/6 mice are treated with saline (control), clindamycin (Clin), a formula containing whey (F1) or buttermilk (F2), Clin+F1 or Clin+F2, and their fecal microbiota profiles are analyzed by sequencing of 16S rRNA gene using the MinION device. Clin induces alterations in both the composition and metabolic functions of the mice intestinal microbiota. The treatment with F1 or F2 reverses the effects of clindamycin, restoring the levels of Rikenellaceae and Lactobacillaceae families and certain pathways related to short-chain fatty acids production and tetrahydrofolate biosynthesis.

CONCLUSION

Whey and buttermilk supplemented with lactoferrin and MFGM may be a bioactive formula for functional foods to prevent or restore microbiota alterations induced by antibiotic administration.

Health benefits of saponins and its mechanisms: perspectives from absorption, metabolism, and interaction with gut

Saponins, consisting of sapogenins as their aglycones and carbohydrate chains, are widely found in plants and some marine organisms. Due to the complexity of the structure of saponins, involving different types of sapogenins and sugar moieties, investigation of their absorption and metabolism is limited, which further hinders the explanation of their bioactivities. Large molecular weight and complex structures limit the direct absorption of saponins rendering their low bioavailability. As such, their major modes of action may be due to interaction with the gastrointestinal environment, such as enzymes and nutrients, and interaction with the gut microbiota. Many studies have reported the interaction between saponins and gut microbiota, that is, the effects of saponins on changing the composition of gut microbiota, and gut microbiota playing an indispensable role in the biotransformation of saponins into sapogenins. However, the metabolic routes of saponins by gut microbiota and their mutual interactions are still sparse. Thus, this review summarizes the chemistry, absorption, and metabolic pathways of saponins, as well as their interactions with gut microbiota and impacts on gut health, to better understand how saponins exert their health-promoting functions.

Polymethoxyflavone-Enriched Fraction from Ougan (Citrus reticulata cv. Suavissima) Attenuated Diabetes and Modulated Gut Microbiota in Diabetic KK-Ay Mice

Diabetes mellitus is a serious, chronic disease worldwide; yet it is largely preventable through physical activity and healthy diets. Ougan (Citrus reticulata cv. Suavissima) is a characteristic citrus variety rich in polymethoxyflavones. In the present study, the anti-diabetic effects of the polymethoxyflavone-enriched fraction from Ougan (OG-PMFs) were investigated. Diabetic KK-Ay mice were supplemented with different doses of OG-PMFs for 5 weeks. Our results demonstrated that OG-PMFs exhibited robust protective effects against diabetes symptoms in KK-Ay mice. The potential mechanisms may partially be attributed to the restoration of hepatic GLUT2 and catalase expression. Notably, OG-PMF administration significantly altered the gut microbiota composition in diabetic KK-Ay, indicated by the suppression of metabolic disease-associated genera Desulfovibrio, Lachnoclostridium, Enterorhabdus, and Ralstonia, implying that the gut microbiota might be another target for OG-PMFs to show effects. Taken together, our results provided a supplementation for the metabolic-protective effects of PMFs and highlighted that OG-PMFs hold great potential to be developed as a functional food ingredient.

Paliurus spina-christi Mill fruit extracts improve glucose uptake and activate the insulin signaling pathways in HepG2 insulin-resistant cells

BACKGROUND

Paliurus spina-christi Mill. (PSC) fruit is frequently used in the treatment of diabetes mellitus in Mediterranean regions. Here, we investigated the effects of various PSC fruit extracts (PSC-FEs) on glucose consumption and some key mediators of insulin signaling pathways in high glucose and high insulin-induced insulin-resistant HepG2 cells.

METHODS

The effects of methanolic, chloroform and total extracts on cell proliferation were assessed by the MTT assay. The potential of non-toxic extracts on glucose utilization in insulin-resistant HepG2 cells was checked using a glucose oxidase assay. AKT and AMP-activated protein kinase (AMPK) pathway activation and mRNA expression levels of insulin receptor (INSR), glucose transporter 1 (GLUT1), and glucose transporters 4 (GLUT4) were determined by western blotting and real-time PCR, respectively.

RESULTS

We found that high concentrations of methanolic and both low and high concentrations of total extracts were able to enhance glucose uptake in an insulin-resistant cell line model. Moreover, AKT and AMPK phosphorylation were significantly increased by the high strength of methanolic extract, while total extract raised AMPK activation at low and high concentrations. Also, GLUT 1, GLUT 4, and INSR were elevated by both methanolic and total extracts.

CONCLUSIONS

Ultimately, our results shed new light on methanolic and total PSC-FEs as sources of potential anti-diabetic medications, restoring glucose consumption and uptake in insulin-resistant HepG2 cells. These could be at least in part due to re-activating AKT and AMPK signaling pathways and also increased expression of INSR, GLUT1, and GLUT4. Overall, active constituents present in methanolic and total extracts of PCS are appropriate anti-diabetic agents and explain the use of these PSC fruits in traditional medicine for the treatment of diabetes.

Role of herbal medicine and gut microbiota in the prevention and treatment of obesity

ETHNOPHARMACOLOGICAL RELEVANCE

Obesity is a common metabolic dysfunction disease, which is highly correlated with the homeostasis of gut microbiota (GM). The dysregulation of GM on energy metabolism, immune response, insulin resistance and endogenous metabolites (e.g., short chain fatty acids and secondary bile acids) can affect the occurrence and development of obesity. Herbal medicine (HM) has particular advantages and definite therapeutic effects in the prevention and treatment of obesity, but its underlying mechanism is not fully clear.

AIM OF THE STUDY

In this review, the representative basic and clinical anti-obesity studies associated with the homeostasis of GM regulated by HM including active components, single herb and herbal formulae were summarized and discussed. We aim to provide a state of art reference for the mechanism research of HM in treating obesity and the further development of new anti-obesity drugs.

MATERIALS AND METHODS

The relevant information was collected by searching keywords (obesity, herbal medicine, prescriptions, mechanism, GM, short chain fatty acids, etc.) from scientific databases (CNKI, PubMed, SpringerLink, Web of Science, SciFinder, etc.).

RESULTS

GM dysbiosis did occur in obese patients and mice, whiles the intervention of GM could ameliorate the condition of obesity. HM (e.g., berberine, Ephedra sinica, Rehjnannia glutinosa, and Buzhong Yiqi prescription) has been proved to possess a certain regulation on GM and an explicit effect on obesity, but the exact mechanism of HM in improving obesity by regulating GM remains superficial.

CONCLUSION

GM is involved in HM against obesity, and GM can be a novel therapeutic target for treating obesity.

Antibiotics administration alleviates the high fat diet-induced obesity through altering the lipid metabolism in young mice

Currently, there is a global trend of rapid increase in obesity, especially among adolescents. The antibiotics cocktails (ABX) therapy is commonly used as an adjunctive treatment for gut microbiota related diseases, including obesity. However, the effects of broad-spectrum antibiotics alone on young obese hosts have rarely been reported. In the present study, the 3-week-old C57BL/6J male mice fed a high-fat diet (HFD) were intragastric administration with ampicillin, vancomycin, metronidazole or neomycin for 30 days. The lipid metabolites in plasma were assessed by biochemical assay kits, and genes related to lipid metabolite in the white adipose were assessed by qPCR. To further analyze the underlying mechanisms, the expression of genes related to lipid metabolism, inflammatory reactions and oxidative stress in the liver were determined by qPCR assay. In addition, the expression of oxidative damage-associated proteins in the liver were detected by western blot. The results showed that oral antibiotics exposure could reduce body weight and fat index in HFD-fed mice, concurrent with the increase of white adipose lipolysis genes and the decrease of hepatic lipogenic genes. Furthermore, antibiotics treatment could clearly reverse the HFD-induced elevation of oxidative damage-related proteins in the liver. Together, these findings will provide valuable clues into the effects of antibiotics on obesity.

Ameliorative effect of bayberry leaves proanthocyanidins on high sugar diet induced Drosophila melanogaster

Bayberry leaves proanthocyanidins (BLPs) were distributed in natural plant food, considered to have the potential for metabolic syndrome. In this study, we raised Drosophila melanogaster on high sugar diet (HSD) from the egg stage to induce hyperglycemia, and the ameliorative effect of BLPs was assessed based on this model. Phenotypical, biochemical, and molecular analyses related to diabetes mellitus pathogenesis were measured. Flies exposed to BLPs were found to suppress the HSD-induced high glucose and high triglycerides levels. Moreover, BLPs showed an inhibitory effect on carbohydrate digestive enzymes (α-amylase and α-glucosidase) activity and mRNA expression, exhibiting the potential for carbohydrate digestion retardation. Transcriptional levels of key genes associated with glycolipid metabolism were further evaluated, including dilp, InR, and downstream dAKT-dFOXO-PEPCK, together with E78, SREBP, FAS, and LSD genes, were all downregulated after BLPs-exposure, suggesting the ameliorative effect of BLPs on dysbiosis associated with the insulin signaling pathway. This study provided a new functional compound, which is beneficial to further antidiabetic therapy studies.