Bidirectional interaction of nobiletin and gut microbiota in mice fed with a high-fat diet

Probiotic therapy modulates the brain-gut-liver microbiota axis in a mouse model of traumatic brain injury

The interplay between gut microbiota and host health is crucial for maintaining the overall health of the body and brain, and it is even more crucial how changes in the bacterial profile can influence the aftermath of traumatic brain injury (TBI). We studied the effects of probiotic treatment after TBI to identify potential changes in hepatic lipid species relevant to brain function. Bioinformatic analysis of the gut microbiota indicated a significant increase in the Firmicutes/Bacteroidetes ratio in the probiotic-treated TBI group compared to sham and untreated TBI groups. Although strong correlations between gut bacteria and hepatic lipids were found in sham mice, TBI disrupted these links, and probiotic treatment did not fully restore them. Probiotic treatment influenced systemic glucose metabolism, suggesting altered metabolic regulation. Behavioral tests confirmed memory improvement in probiotic-treated TBI mice. While TBI reduced hippocampal mRNA expression of CaMKII and CREB, probiotics reversed these effects yet did not alter BDNF mRNA levels. Elevated pro-inflammatory markers TNF-α and IL1-β in TBI mice were not significantly affected by probiotic treatment, pointing to different mechanisms underlying the probiotic benefits. In summary, our study suggests that TBI induces dysbiosis, alters hepatic lipid profiles, and preemptive administration of Lactobacillus helveticus and Bifidobacterium longum probiotics can counter neuroplasticity deficits and memory impairment. Altogether, these findings highlight the potential of probiotics for attenuating TBI's detrimental cognitive and metabolic effects through gut microbiome modulation and hepatic lipidomic alteration, laying the groundwork for probiotics as a potential TBI therapy.

Microbes: Drivers of Chenpi manufacturing, biotransformation, and physiological effects

Chenpi holds a rich history of both edible and medicinal applications worldwide, garnering increased attention from researchers in recent years due to its diverse physiological effects. While current research predominantly exploresed its chemical composition and physiological effects, there remains a notable gap in knowledge concerning its manufacturing, characteristic chemical substances, and the underlying mechanisms driving its physiological effects. In this review, the impacts of microbes on the manufacturing, biotransformation, and physiological effects of Chenpi were summarized, as well as the present status of product development. Furthermore, this review engaged in an in-depth discussion highlighting the challenges and shortcomings in recent research, while proposing potential directions and prospects. Additionally, the claim that "The longer the aging, the better the quality" of Chenpi was scientifically evaluated for the first time, providing a solid theoretical foundation for advancing the Chenpi industry.

The impact of traditional Chinese medicine and dietary compounds on modulating gut microbiota in hepatic fibrosis: A review

Traditional Chinese medicine (TCM) and dietary compounds have a profound influence on the regulation of gut microbiota (GM) in hepatic fibrosis (HF). Certain substances found in both food and herbs that are edible and medicinal, such as dietary fiber, polyphenols, and polysaccharides, can generate beneficial metabolites like short-chain fatty acids (SCFAs), bile acids (BAs), and tryptophan (Trp). These compounds contribute to regulate the GM, reduce levels of endotoxins in the liver, and alleviate fibrosis and inflammation in the liver. Furthermore, they enhance the composition and functionality of GM, promoting the growth of beneficial bacteria while inhibiting the proliferation of harmful bacteria. These mechanisms mitigate the inflammatory response in the intestines and maintain the integrity of the intestinal barrier. The purpose of this review is to analyze how the GM regulates the pathogenesis of HF, evaluate the regulatory effect of TCM and dietary compounds on the intestinal microflora, with a particular emphasis on modulating flora structure, enhancing gut barrier function, and addressing associated pathogenic factors, thereby provide new insights for the treatment of HF.

Dietary astragalin confers protection against lipopolysaccharide-induced intestinal mucosal barrier damage through mitigating inflammation and modulating intestinal microbiota

Introduction

The intestinal mucosal barrier (IMB) damage is intricately linked with the onset of numerous intestinal diseases. Astragalin (AS), a flavonoid present in numerous edible plants, exhibits notable antioxidant and anti-inflammatory properties, demonstrating a promising impact on certain intestinal ailments. In this study, our objective was to investigate the protective effects of AS and elucidate the underlying mechanisms by which it mitigates lipopolysaccharide (LPS)-induced damage to the IMB in mice.

Methods

During the experimental period, mice were subjected to a 7-day regimen of AS treatment, followed by LPS injection to induce IMB damage. Subsequently, a comprehensive evaluation of relevant biological indicators was conducted, including intestinal pathological analysis, serum inflammatory factors, intestinal tight junction proteins, and intestinal microbiota composition.

Results

Our results suggested that AS treatment significantly bolstered IMB function. This was evidenced by the enhanced morphology of the small intestine and the elevated expression of tight junction proteins, including ZO-1 and Claudin-1, in addition to increased levels of MUC2 mucin. Moreover, the administration of AS demonstrated a mitigating effect on intestinal inflammation, as indicated by the reduced plasma concentrations of pro-inflammatory cytokines such as IL-6, IL-1β, and TNF-α. Furthermore, AS treatment exerted a positive influence on the composition of the gut microbiota, primarily by augmenting the relative abundance of beneficial bacteria (including Lachnospiracea and Lactobacillus murinus), while simultaneously reducing the prevalence of the harmful bacterium Mucispirillum schaedleri.

Conclusion

AS mitigates LPS-induced IMB damage via mitigating inflammation and modulating intestinal microbiota.

A Comprehensive Review of the Triangular Relationship among Diet-Gut Microbiota-Inflammation

The human gastrointestinal tract hosts a complex and dynamic community of microorganisms known as the gut microbiota, which play a pivotal role in numerous physiological processes, including digestion, metabolism, and immune function. Recent research has highlighted the significant impact of diet on the gut microbiota composition and functionality, and the consequential effects on host health. Concurrently, there is growing evidence linking the gut microbiota to inflammation, a key factor in many chronic diseases such as inflammatory bowel disease (IBD), obesity, diabetes, and cardiovascular diseases (CVDs). This review explores how dietary components influence the gut microbiota composition, how these microbial changes affect inflammatory pathways, and the therapeutic implications of modulating this axis for chronic inflammatory disease prevention and management. Beneficial dietary patterns, such as the Mediterranean diet (MD) and plant-based diets, promote a diverse and balanced gut microbiota composition, supporting anti-inflammatory pathways. Conversely, the Western diet (WD), high in saturated fats and refined sugars, is associated with dysbiosis and increased inflammation. With all the links between the three variables considered, this review attempts to offer a thorough examination of the triangle formed by inflammation, the gut microbiota, and food.

Glucosinolate extract from radish (Raphanus sativus L.) seed attenuates high-fat diet-induced obesity: insights into gut microbiota and fecal metabolites

Background

Radish seed is a functional food with many beneficial health effects. Glucosinolates are characteristic components in radish seed that can be transformed into bioactive isothiocyanates by gut microbiota.

Objective

The present study aims to assess anti-obesity efficacy of radish seed glucosinolates (RSGs) and explored the underlying mechanisms with a focus on gut microbiota and fecal metabolome.

Methods

High-fat diet-induced obese mice were supplemented with different doses of RSGs extract for 8 weeks. Changes in body weight, serum lipid, alanine aminotransferase (ALT), and aspartate aminotransferase (AST) levels; and pathological changes in the liver and adipose tissue were examined. Fecal metabolome and 16S rRNA gene sequencing were used to analyze alterations in fecal metabolite abundance and the gut microbiota, respectively.

Results and conclusion

Results showed that RSG extract prevented weight gain and decreased serum lipid, ALT, AST levels and lipid deposition in liver and epididymal adipocytes in obese mice. Treatment with RSG extract also increased gut microbiota diversity and altered the dominant bacteria genera in the gut microbiota, decreasing the abundance of Faecalibaculum and increasing the abundance of Allobaculum, Romboutsia, Turicibacter, and Akkermansia. Fecal metabolome results identified 570 differentially abundant metabolites, of which glucosinolate degradation products, such as sulforaphene and 7-methylsulfinylheptyl isothiocyanate, were significantly upregulated after RSG extract intervention. Furthermore, enrichment analysis of metabolic pathways showed that the anti-obesity effects of RSG extract may be mediated by alterations in bile secretion, fat digestion and absorption, and biosynthesis of plant secondary metabolites. Overall, RSG extract can inhibit the development of obesity, and the obesity-alleviating effects of RSG are related to alternative regulation of the gut microbiota and glucosinolate metabolites.

Anti-Obesity Activity of Sanghuangporus vaninii by Inhibiting Inflammation in Mice Fed a High-Fat Diet

Obesity is an unhealthy condition associated with various diseases characterized by excess fat accumulation. However, in China, the prevalence of obesity is 14.1%, and it remains challenging to achieve weight loss or resolve this issue through clinical interventions. Sanghuangpours vaninii (SPV) is a nutritional fungus with multiple pharmacological activities and serves as an ideal dietary intervention for combating obesity. In this study, a long-term high-fat diet (HFD) was administered to induce obesity in mice. Different doses of SPV and the positive drug simvastatin (SV) were administered to mice to explore their potential anti-obesity effects. SPV regulated weight, serum lipids, and adipocyte size while inhibiting inflammation and hepatic steatosis. Compared with the vehicle-treated HFD-fed mice, the lowest decreases in total cholesterol (TC), triglycerides (TG), and low-density lipoprotein cholesterol (LDL-C) were 9.72%, 9.29%, and 12.29%, respectively, and the lowest increase in high-density lipoprotein cholesterol (HDL-C) was 5.88% after treatment with different doses of SPV. With SPV treatment, the analysis of gut microbiota and serum lipids revealed a significant association between lipids and inflammation-related factors, specifically sphingomyelin. Moreover, Western blotting results showed that SPV regulated the toll-like receptor (TLR4)/nuclear factor kappa B (NF-κB) signaling pathway in HFD-diet mice, which is related to inflammation and lipid metabolism. This research presents empirical proof of the impact of SPV therapy on obesity conditions.

Plant-derived flavonoids are a potential source of drugs for the treatment of liver fibrosis

Liver fibrosis is a dynamic pathological process that can be triggered by any chronic liver injury. If left unaddressed, it will inevitably progress to the severe outcomes of liver cirrhosis or even hepatocellular carcinoma. In the past few years, the prevalence and fatality of hepatic fibrosis have been steadily rising on a global scale. As a result of its intricate pathogenesis, the quest for pharmacological interventions targeting liver fibrosis has remained a formidable challenge. Currently, no pharmaceuticals are exhibiting substantial clinical efficacy in the management of hepatic fibrosis. Hence, it is of utmost importance to expedite the development of novel therapeutics for the treatment of this condition. Various research studies have revealed the ability of different natural flavonoid compounds to alleviate or reverse hepatic fibrosis through a range of mechanisms, which are related to the regulation of liver inflammation, oxidative stress, synthesis and secretion of fibrosis-related factors, hepatic stellate cells activation, and proliferation, and extracellular matrix synthesis and degradation by these compounds. This review summarizes the progress of research on different sources of natural flavonoids with inhibitory effects on liver fibrosis over the last decades. The anti-fibrotic effects of natural flavonoids have been increasingly studied, making them a potential source of drugs for the treatment of liver fibrosis due to their good efficacy and biosafety.

Nobiletin from citrus peel: a promising therapeutic agent for liver disease-pharmacological characteristics, mechanisms, and potential applications

Nobiletin (NOB) is a flavonoid derived from citrus peel that has potential as an alternative treatment for liver disease. Liver disease is a primary health concern globally, and there is an urgent need for effective drugs. This review summarizes the pharmacological characteristics of NOB and current in vitro and in vivo studies investigating the preventive and therapeutic effects of NOB on liver diseases and its potential mechanisms. The findings suggest that NOB has promising therapeutic potential in liver diseases. It improves liver function, reduces inflammation and oxidative stress, remodels gut microflora, ameliorates hepatocellular necrosis, steatosis, and insulin resistance, and modulates biorhythms. Nuclear factor erythroid 2-related factor 2 (Nrf2), nuclear transcription factor kappa (NF-κB), AMP-activated protein kinase (AMPK), peroxisome proliferator-activated receptor α(PPAR-α), extracellular signal-regulated kinase (ERK), protein kinase B (AKT), toll-like receptor 4 (TLR4) and transcription factor EB (TFEB) signaling pathways are important molecular targets for NOB to ameliorate liver diseases. In conclusion, NOB may be a promising drug candidate for treating liver disease and can accelerate its application from the laboratory to the clinic. However, more high-quality clinical trials are required to validate its efficacy and identify its molecular mechanisms and targets.

The polysaccharides from the fruits of Lycium barbarum ameliorate high-fat and high-fructose diet-induced cognitive impairment via regulating blood glucose and mediating gut microbiota

High-fat and high-fructose diet (HFFD) consumption can induce cognitive dysfunction and gut microbiota disorder. In the present study, the effects of the polysaccharides from the fruits of Lycium barbarum L. (LBPs) on HFFD-induced cognitive deficits and gut microbiota dysbiosis were investigated. The results showed that intervention of LBPs (200 mg/kg/day) for 14 weeks could significantly prevent learning and memory deficits in HFFD-fed mice, evidenced by a reduction of latency and increment of crossing parameters of platform quadrant in Morris water maze test. Moreover, oral administration of LBPs enhanced the expression of postsynaptic density protein 95 and brain-derived neurotrophic factor and reduced the activation of glial cells in hippocampus. Besides, LBPs treatment enriched the relative abundances of Allobaculum and Lactococcus and reduced the relative abundance of Proteobacteria in gut bacterial community of HFFD-fed mice, accompanied by increased levels of short-chain fatty acids (SCFAs) as well as expression of associated G protein-coupled receptors. Furthermore, LBPs intervention prevented insulin resistance, obesity and colonic inflammation. Finally, a significant correlation was observed among neuroinflammation associated parameters, gut microbiota and SCFAs through Pearson correlation analysis. Collectively, these findings suggested that the regulation of gut microbiota might be the potential mechanism of LBPs on preventing cognitive dysfunction induced by HFFD.

Polymethoxylated flavonoids in citrus fruits: absorption, metabolism, and anticancer mechanisms against breast cancer

Polymethoxylated flavonoids (PMFs) are a subclass of flavonoids found in citrus fruits that have shown multifunctional biological activities and potential anticancer effects against breast cancer. We studied the absorption, metabolism, species source, toxicity, anti-cancer mechanisms, and molecular targets of PMFs to better utilize their anticancer activity against breast cancer. We discuss the absorption and metabolism of PMFs in the body, including the methylation, demethylation, and hydroxylation processes. The anticancer mechanisms of PMFs against breast cancer were also reviewed, including the estrogen activity, cytochrome P-450 enzyme system, and arylhydrocarbon receptor (AhR) inhibition, along with various molecular targets and potential anticancer effects. Although PMFs may be advantageous in the prevention and treatment for breast cancer, there is a lack of clinical evidence and data to support their efficacy. Despite their promise, there is still a long way to go before PMFs can be applied clinically.

A review on recent advances on nobiletin in central and peripheral nervous system diseases

In recent years, the role of nobiletin in neuronal disorders has received extensive attention. However, the study of nobiletin in the peripheral nervous system is limited. Nobiletin, as a compound with high fat solubility, high bioavailability and low toxicity, has been extensively studied. Accumulating scientific evidence has shown that nobiletin has a variety of biological functions in the nervous system, such as inhibiting the expression of inflammatory factors, reducing the neurotoxic response, improving the antioxidant capacity, promoting the survival of nerve cells, promoting axon growth, reducing blood‒brain barrier permeability, reducing brain oedema, promoting cAMP response element binding protein expression, improving memory, and promoting mild depolarization of nerve cell mitochondria to improve antioxidative stress capacity. Accumulating studies have shown that nobiletin also protects enteric nervous system, spinal cord and sciatic nerve. To explore the new therapeutic potential of nobiletin in the nervous system, recent and relevant research progress is reviewed in this article. This will provide a new research idea for nobiletin in the nervous system.

Gut Microbiota Combined with Serum Metabolomics to Investigate the Hypoglycemic Effect of Actinidia arguta Leaves

Actinidia arguta leaves (AAL) are an excellent source of bioactive components for the food industry and possess many functional properties. However, the hypoglycemic effect and mechanism of AAL remain unclear. The aim of this work was to investigate the potential hypoglycemic effect of AAL and explore its possible mechanism using 16S rRNA sequencing and serum metabolomics in diabetic mice induced by high-fat feeding in combination with streptozotocin injection. A total of 25 flavonoids from AAL were isolated and characterized, and the contents of the extract from the AAL ranged from 0.14 mg/g DW to 8.97 mg/g DW. The compound quercetin (2) had the highest content of 8.97 ± 0.09 mg/g DW, and the compound kaempferol-3-O-(2'-O-D-glucopyl)-β-D-rutinoside (12) had the lowest content of 0.14 ± 0.01 mg/g DW. In vivo experimental studies showed that AAL reduced blood glucose and cholesterol levels, improved insulin sensitivity, and ameliorated oxidative stress and liver and kidney pathological damage. In addition, gut microbiota analysis found that AAL significantly reduced the F/B ratio, enriched the beneficial bacteria Bacteroides and Bifidobacterium, and inhibited the harmful bacteria Lactobacillus and Desulfovibrio, thereby playing an active role in intestinal imbalance. In addition, metabolomics analysis showed that AAL could improve amino acid metabolism and arachidonic acid metabolism, thereby exerting a hypoglycemic effect. This study confirmed that AAL can alleviate type 2 diabetes mellitus (T2DM) by regulating intestinal flora and interfering with related metabolic pathways, providing a scientific basis for its use as a dietary supplement and for further exploration of the mechanism of AAL against T2DM.

Nobiletin protects against ferroptosis to alleviate sepsis-associated acute liver injury by modulating the gut microbiota

Nobiletin (NOB), a plant-based polymethoxyflavone, is a promising protective agent against sepsis; yet the mechanisms were not fully elucidated. The gut microbiota is found to be strongly associated with sepsis-associated acute liver injury (SALI). Here, our study aimed to evaluate the protective effect of NOB on SALI and explore the underlying molecular mechanisms. Cecal ligation and puncture (CLP) was used to induce SALI in mice. NOB was administered by gavage for 7 days before CLP induction. The 16S rRNA gene sequencing and fecal microbiota transplantation (FMT) were performed to verify the function of the gut microbiota. The markers of ferroptosis, inflammation, gut microbiota composition, and liver injury were determined. NOB administration significantly alleviated hepatic ferroptosis and inflammation in septic mice. Meanwhile, NOB upregulated the expression levels of nuclear factor E2-related factor 2 (Nrf2) and its downstream protein heme oxygenase-1 (HO-1). The protective effect of NOB administration against ferroptosis in SALI mice was reversed by the Nrf2 inhibitor ML385. Additionally, increased abundances of Ligilactobacillus, Akkermansia, and Lactobacillus, and decreased abundances of Dubosiella and Bacteroides in the gut were observed under NOB administration, suggesting that NOB might modulate the gut microbiota composition of septic mice. Furthermore, gut microbiota ablation by antibiotic treatment partly reversed the protective effects of NOB on sepsis. FMT also confirmed that NOB inhibited ferroptosis and activated Nrf2 signalling in SALI mice by modulating the gut microbiota. These results revealed that, by modulating the gut microbiota, NOB attenuated ferroptosis in septic liver injury through upregulating Nrf2-Gpx4. Our findings provide novel insights into microbiome-based therapeutic approaches for sepsis.

Novel application potential of cinaciguat in the treatment of mixed hyperlipidemia through targeting PTL/NPC1L1 and alleviating intestinal microbiota dysbiosis and metabolic disorders

Mixed hyperlipidemia, characterized by high levels of triglycerides and cholesterol, is a key risk factor leading to atherosclerosis and other cardiovascular diseases. Existing clinical drugs usually only work on a single indicator, decreasing either triglyceride or cholesterol levels. Developing dual-acting agents that reduce both triglycerides and cholesterol remains a great challenge. Pancreatic triglyceride lipase (PTL) and Niemann-Pick C1-like 1 (NPC1L1) have been identified as crucial proteins in the transport of triglycerides and cholesterol. Here, cinaciguat, a known agent used in the treatment of acute decompensated heart failure, was identified as a potent dual inhibitor targeting PTL and NPC1L1. We presented in vitro evidence from surface plasmon resonance analysis that cinaciguat interacted with PTL and NPC1L1. Furthermore, cinaciguat exhibited potent PTL-inhibition activity. Fluorescence-labeled cholesterol uptake analysis and confocal imaging showed that cinaciguat effectively inhibited cholesterol uptake. In vivo evaluation showed that cinaciguat significantly reduced the plasma levels of triglycerides and cholesterol, and effectively alleviated high-fat diet-induced intestinal microbiota dysbiosis and metabolic disorders. These results collectively suggest that cinaciguat has the potential to be further developed for the therapy of mixed hyperlipidemia.

Review of recent advances on health benefits, microbial transformations, and authenticity identification of Citri reticulatae Pericarpium bioactive compounds

The extensive health-promoting effects of Citri Reticulatae Pericarpium (CRP) have attracted researchers' interest. The difference in storage time, varieties and origin of CRP are closely related to the content of bioactive compounds they contain. The consitituent transformation mediated by environmental microorganisms (bacteria and fungi) and the production of new bioactive components during the storage process may be the main reason for 'the older, the better' of CRP. In addition, the gap in price between different varieties can be as large as 8 times, while the difference due to age can even reach 20 times, making the 'marketing young-CRP as old-CRP and counterfeiting origin' flood the entire market, seriously harming consumers' interests. However, so far, the research on CRP is relatively decentralized. In particular, a summary of the microbial transformation and authenticity identification of CRP has not been reported. Therefore, this review systematically summarized the recent advances on the main bioactive compounds, the major biological activities, the microbial transformation process, the structure, and content changes of the active substances during the transformation process, and authenticity identification of CRP. Furthermore, challenges and perspectives concerning the future research on CRP were proposed.

Dietary sinensetin and polymethoxyflavonoids: Bioavailability and potential metabolic syndrome-related bioactivity

Sinensetin is among the most ubiquitous polyphenols in citrus fruit and recently has been extensively studied for its ability to prevent or treat diseases. The current literature on the bioavailability of sinensetin and its derivatives was reviewed and the potential ameliorative effects of metabolic syndrome in humans were evaluated. Sinensetin and its derivatives mainly aggregated in the large intestine and extensively metabolized through gut microbiota (GM) and the liver. So intestinal microorganisms had a significant influence on the absorption and metabolism of sinensetin. Interestingly, not only GM acted on sinensetin to metabolize them, but sinensetin also regulated the composition of GM. Thus, sinensetin was metabolized as methyl, glucuronide and sulfate metabolites in the blood and urine. Furthermore, sinensetin was reported to have the beneficial effect of ameliorating metabolic syndromes, including disorders of lipid metabolism (obesity, NAFLD, atherosclerosis), glucose metabolism disorder (insulin resistant) and inflammation, in terms of improving the composition of intestinal flora and modulating metabolic pathway factors in relevant tissues. The present work strongly elucidated the potential mechanism of sinensetin in improving metabolic disorders and supported the contribution of sinensetin to health benefits, thus offering a better perspective in understanding the role played by sinensetin in human health.

Structural characteristics of mixed pectin from ginseng berry and its anti-obesity effects by regulating the intestinal flora

Ginseng berry is the mature berry of ginseng and its polysaccharide has hypolipidaemic effect, but its mechanism remains unclear. A pectin (GBPA) with a molecular weight of 3.53 × 10⁴ Da was isolated from ginseng berry, it was mainly composed of Rha (25.54 %), GalA (34.21 %), Gal (14.09 %) and Ara (16.25 %). Structural analysis showed that GBPA is a mixed pectin containing rhamnogalacturonan-I and homogalacturonan domains and has a triple helix structure. GBPA distinctly improved lipid disorders in obese rats, and changed intestinal flora with enrichments of Akkermansia, Bifidobacterium, Bacteroides and Prevotella, improved the levels of acetic acid, propionic acid, butyric acid and valeric acid. Serum metabolites which involved in the lipid regulation-related pathway, including cinnzeylanine, 10-Hydroxy-8-nor-2-fenchanone glucoside, armillaribin, 24-Propylcholestan-3-ol, were also greatly changed after GBPA treatment. GBPA activated AMP-activated protein kinase, phosphorylated acetyl-CoA carboxylase, and reduced the expression of lipid synthesis-related genes sterol regulatory element-binding protein-1c and fatty acid synthases. The regulatory effects of GBPA on lipid disorders in obese rats are related to the regulation of intestinal flora and activation of AMP-activated protein kinase pathway. Ginseng berry pectin could be considered in the future as a health food or medicine to prevent obesity.

Evolving interplay between natural products and gut microbiota

Growing evidence suggests gut microbiota status affects human health, and microbiota imbalance will induce multiple disorders. Natural products are gaining increasing attention for their therapeutical effects and less side effects. The emerging studies support that the activities of many natural products are dependent on gut microbiota, meanwhile gut microbiota is modulated by natural products. In this review, we summarized the interplay between the gut microbiota and host disease, and the emerging molecular mechanisms of the interaction between natural products and gut microbiota. Focusing on gut microbiota metabolite of various natural products, and the effects of natural products on gut microbiota, we summarized the biotransformation pathways of natural products, and discussed the effect of natural products on the composition modulation of gut microbiota, protection of gut mucosal barrier and modulation of the gut microbiota metabolites. Dissecting the interplay between gut microbiota and natural products will help elucidate the therapeutic mechanisms of natural products.

Antidiabetic effect of sciadonic acid on type 2 diabetic mice through activating the PI3K-AKT signaling pathway and altering intestinal flora

Type 2 diabetes mellitus (T2DM) is a metabolic disease characterized by hyperglycemia. The aim of this work was to investigate the effect of sciadonic acid (SA) on disorders of glucolipid metabolism and intestinal flora imbalance and to further investigate its potential molecular mechanism of anti-diabetes. The experimental data indicated that SA could alleviate hyperlipidemia, insulin resistance, oxidative stress, the inflammatory response, repair liver function damage, and promote glycogen synthesis caused by T2DM. SA could also activate the PI3K/AKT/GLUT-2 signaling pathway, promote glucose metabolism gene expression, and maintain glucose homeostasis. Furthermore, 16S rRNA analysis revealed that SA could reduce the Firmicutes/Bacteroidota (F/B) ratio; promote norank_f__Muribaculaceae, Allobaculum, Akkermansia, and Eubacterium_siraeum_group proliferation; increase the levels of major short-chain fatty acids (SCFAs), such as acetic acid, propionic acid, and butyric acid; and maintain the homeostasis of the intestinal flora. In conclusion, these results suggested that SA could reshape the structural composition of intestinal microbes, activate the PI3K/AKT/GLUT2 pathway, improve insulin resistance, and decrease blood glucose levels.

Dietary supplementation with selenium nanoparticles-enriched Lactobacillus casei ATCC 393 alleviates intestinal barrier dysfunction of mice exposed to deoxynivalenol by regulating endoplasmic reticulum stress and gut microbiota

Deoxynivalenol (DON), a secondary product of Fusarium metabolism, is common in wheat, corn, barley and other grain crops, posing a variety of adverse effects to environment, food safety, human and animal health. The absorption of DON mainly occurs in the proximal part of the small intestine, which can induce intestinal mucosal epithelial injury, and ultimately affect the growth performance and production performance of animals. This study was conducted to investigate the protective effects of selenium nanoparticles (SeNPs)-enriched Lactobacillus casei ATCC 393 (L. casei ATCC 393) on intestinal barrier function of C57BL/6 mice exposed to DON and its association with endoplasmic reticulum stress (ERS) and gut microbiota. The results showed that DON exposure increased the levels of interleukin-6 (IL-6) and interleukin-8 (IL-8), decreased the levels of interleukin-10 (IL-10) and transforming growth factor beta (TGF-β), caused a redox imbalance and intestinal barrier dysfunction, decreased the mRNA levels of endoplasmic reticulum- resident selenoproteins, activated ERS-protein kinase R-like endoplasmic reticulum kinase (PERK) signaling pathway, altered the composition of the gut microbiota and decreased short-chain fatty acids (SCFAs) content. Dietary supplementation with SeNPs-enriched L. casei ATCC 393 can effectively protect the integrity of intestinal barrier function by reducing inflammatory response, enhancing the antioxidant capacity, up-regulating the mRNA levels of endoplasmic reticulum-resident selenoproteins, inhibiting the activation of PERK signaling pathway, reversing gut microbiota dysbiosis and increasing the content of SCFAs in mice exposed to DON. In conclusion, dietary supplementation with SeNPs-enriched L. casei ATCC 393 effectively alleviated intestinal barrier dysfunction induced by DON in C57BL/6 mice, which may be closely associated with the regulation of ERS and gut microbiota.

Virtual screening analysis of natural flavonoids as trimethylamine (TMA)-lyase inhibitors for coronary heart disease

Coronary heart disease (CHD) is defined by atherosclerosis, which can result in stenosis or blockage of the arterial cavity, leading to ischemic cardiac diseases such as angina and myocardial infarction. Accumulating evidence indicates that the gut microbiota plays a vital role in the beginning and progression of CHD. The gut microbial metabolite, trimethylamine-N-oxide (TMAO), is intimately linked to the pathophysiology of CHD. TMAO is formed when trimethylamine (TMA) is converted by flavin-containing monooxygenases in the hepatocytes. Therefore, inhibition of TMA production is essential to reduce TMAO levels. Flavonoids may reduce the risk of death from cardiovascular disease. In this article, we reviewed and evaluated twenty-two flavonoids for the therapy of CHD based on their inhibition of TMA-lyase by molecular docking. Docking results revealed that baicalein, fisetin, acacetin, and myricetin in flavonoid aglycones, and baicalin, naringin, and hesperidin in flavonoid glycosides had a good binding effect with TMA-lyase. This indicates that these chemicals were the most active and could be used as lead compounds for structural modification in the future. PRACTICAL APPLICATIONS: Flavonoids are a large class of polyphenolic compounds found in fruits, vegetables, flowers, tea, and herbal medicines, which are inexorably metabolized and transformed into bioactive metabolites by α-rhamnosidase, β-glucuronidase, β-glucosidase, and nitroreductase produced by the gut microbiota, which plays a beneficial role in the prevention and treatment of cardiovascular diseases. Because flavonoids protect the cardiovascular system and regulate the gut microbiota, and the gut microbiota is directly connected to TMAO, thus, reducing TMAO levels involves blocking the transition of TMA to TMAO, which may be performed by reducing TMA synthesis. Molecular docking results found that baicalein, fisetin, acacetin, and myricetin in flavonoid aglycones, and baicalin, naringin, and hesperidin in flavonoid glycosides had good binding effects on TMA-lyase, which were the most active and could be used as lead compounds for structural modification.

Diet-Related Changes of Short-Chain Fatty Acids in Blood and Feces in Obesity and Metabolic Syndrome

Obesity-related illnesses are one of the leading causes of death worldwide. Metabolic syndrome has been associated with numerous health issues. Short-chain fatty acids (SCFAs) have been shown to have multiple effects throughout the body, both directly as well as through specific G protein-coupled receptors. The main SCFAs produced by the gut microbiota are acetate, propionate, and butyrate, which are absorbed in varying degrees from the large intestine, with some acting mainly locally and others systemically. Diet has the potential to influence the gut microbial composition, as well as the type and amount of SCFAs produced. High fiber-containing foods and supplements increase the production of SCFAs and SCFA-producing bacteria in the gut and have been shown to have bodyweight-lowering effects. Dietary supplements, which increase SCFA production, could open the way for novel approaches to weight loss interventions. The aim of this review is to analyze the variations of fecal and blood SCFAs in obesity and metabolic syndrome through a systematic search and analysis of existing literature.

Mechanism of Citri Reticulatae Pericarpium as an Anticancer Agent from the Perspective of Flavonoids: A Review

Citri Reticulatae Pericarpium (CRP), also known as “chenpi”, is the most common qi-regulating drug in traditional Chinese medicine. It is often used to treat cough and indigestion, but in recent years, it has been found to have multi-faceted anti-cancer effects. This article reviews the pharmacology of CRP and the mechanism of the action of flavonoids, the key components of CRP, against cancers including breast cancer, lung cancer, prostate cancer, hepatic carcinoma, gastric cancer, colorectal cancer, esophageal cancer, cervical cancer, bladder cancer and other cancers with a high diagnosis rate. Finally, the specific roles of CRP in important phenotypes such as cell proliferation, apoptosis, autophagy and migration–invasion in cancer were analyzed, and the possible prospects and deficiencies of CRP as an anticancer agent were evaluated.

Hypoglycemic Effect of Nobiletin via Regulation of Islet β-Cell Mitophagy and Gut Microbiota Homeostasis in Streptozocin-Challenged Mice

Nobiletin is a natural nutrient (or polymethoxyflavonoid) in orange peels exerting a preventive effect against metabolic diseases. However, there are very few reports on the hypoglycemic effect of nobiletin. In the present study, the hypoglycemic effect of nobiletin was investigated using NIT-1 cells and streptozocin (STZ)-challenged mouse models. Our results indicated that nobiletin could significantly suppress the high blood glucose in STZ-challenged mice. In addition, nobiletin could effectively activate the mitophagy and inhibit the inflammatory pathways in NIT-1 cells. The mitochondria membrane potential dysbiosis induced by glucotoxicity in NIT-1 cells was restored after treatment by nobiletin. Further investigation revealed that the hypoglycemic effect of nobiletin was mainly through regulation of gut microbiota dysbiosis, activation of mitophagy flux, inhibition of inflammasome expression, and restoration of islet morphological destruction in the pancreas of STZ-challenged mice. Our study revealed that nobiletin could be used as a functional food or drug candidate for the treatment of diabetes.

Nobiletin ameliorates high fat-induced disruptions in rhythmic glucagon-like peptide-1 secretion

The incretin hormone glucagon-like peptide-1 (GLP-1) is secreted by the intestinal L cell in response to nutrient intake. However, GLP-1 secretion also follows a circadian rhythm which is disrupted by the saturated fatty acid palmitate in vitro and high-fat diet (HFD) feeding in vivo. The flavonoid nobiletin is a clock enhancer which improves metabolic homeostasis. Therefore, the aim of this study was to elucidate whether and how nobiletin mitigates the negative effects of palmitate and HFD-feeding on rhythmic GLP-1 release. Pre-treatment of murine GLUTag L cells with palmitate dampened the GLP-1 secretory response at the normal peak of secretion, while nobiletin co-treatment restored GLP-1 secretion and upregulated the ‘metabolic pathway’ transcriptome. Mice fed a HFD also lost their GLP-1 secretory rhythm in association with markedly increased GLP-1 levels and upregulation of L cell transcriptional pathways related to ‘sensing’ and ‘transducing’ cellular stimuli at the normal peak of GLP-1 release. Nobiletin co-administration reduced GLP-1 levels to more physiological levels and upregulated L cell ‘oxidative metabolism’ transcriptional pathways. Furthermore, nobiletin improved colonic microbial 16S rRNA gene diversity and reduced the levels of Proteobacteria in HFD-fed mice. Collectively, this study establishes that nobiletin improves the normal rhythm in GLP-1 secretion following fat-induced disruption.

A Narrative Review of the Effects of Citrus Peels and Extracts on Human Brain Health and Metabolism

As life expectancy increases, age-associated diseases such as Alzheimer's disease (AD) become a major health problem. The onset of AD involves neurological dysfunction due to amyloid-β accumulation, tau hyperphosphorylation, oxidative stress, and neuroinflammation in the brain. In addition, lifestyle-related diseases-such as dyslipidemia, diabetes, obesity, and vascular dysfunction-increase the risk of developing dementia. The world population ages, prompting the development of new strategies to maintain brain health and prevent the onset of dementia in older and preclinical patients. Citrus fruits are abundant polymethoxylated flavone and flavanone sources. Preclinical studies reported that these compounds have neuroprotective effects in models of dementia such as AD. Interestingly, clinical and epidemiological studies appear to support preclinical evidence and show improved cognitive function and reduced associated disease risk in healthy individuals and/or patients. This review summarizes the recent evidence of the beneficial effects of citrus peels and extracts on human cognition and related functions.

Intake of flavonoids from Astragalus membranaceus ameliorated brain impairment in diabetic mice via modulating brain-gut axis

Background

Brain impairment is one of a major complication of diabetes. Dietary flavonoids have been recommended to prevent brain damage. Astragalus membranaceus is a herbal medicine commonly used to relieve the complications of diabetes. Flavonoids is one of the major ingredients of Astragalus membranaceus, but its function and mechanism on diabetic encepholopathy is still unknown.

Methods

Type 2 diabetes mellitus (T2DM) model was induced by high fat diet and STZ in C57BL/6J mice, and BEnd.3 and HT22 cell lines were applied in the in vitro study. Quality of flavonoids was evaluated by LC–MS/MS. Differential expressed proteins in the hippocampus were evaluated by proteomics; influence of the flavonoids on composition of gut microbiota was analyzed by metagenomics. Mechanism of the flavonoids on diabetic encepholopathy was analyzed by Q-PCR, Western Blot, and multi-immunological methods et al.

Results

We found that flavonoids from Astragalus membranaceus (TFA) significantly ameliorated brain damage by modulating gut-microbiota-brain axis: TFA oral administration decreased fasting blood glucose and food intake, repaired blood brain barrier, protected hippocampus synaptic function; improved hippocampus mitochondrial biosynthesis and energy metabolism; and enriched the intestinal microbiome in high fat diet/STZ-induced diabetic mice. In the in vitro study, we found TFA increased viability of HT22 cells and preserved gut barrier integrity in CaCO₂ monocellular layer, and PGC1α/AMPK pathway participated in this process.

Conclusion

Our findings demonstrated that flavonoids from Astragalus membranaceus ameliorated brain impairment, and its modulation on gut-brain axis plays a pivotal role. Our present study provided an alternative solution on preventing and treating diabetic cognition impairment.

Citrus reticulatae pericarpium Extract Decreases the Susceptibility to HFD-Induced Glycolipid Metabolism Disorder in Mice Exposed to Azithromycin in Early Life

Background

Studies have shown that gut microbe disorder in mice due to early-life antibiotic exposure promotes glycolipid metabolism disorder in adulthood. However, the underlying mechanism remains unclear and there is not yet an effective intervention or treatment for this process.

Purpose

The study investigated whether early-life azithromycin (AZT) exposure in mice could promote high-fat diet (HFD)-induced glycolipid metabolism disorder in adulthood. Moreover, the effect of citrus reticulata pericarpium (CRP) extract on glycolipid metabolism disorder via regulation of gut microbiome in mice exposed to antibodies early in life were investigated.

Methods and Results

Three-week-old mice were treated with AZT (50 mg/kg/day) via drinking water for two weeks and then were fed a CRP diet (1% CRP extract) for four weeks and an HFD for five weeks. The results showed that early-life AZT exposure promoted HFD-induced glycolipid metabolism disorder, increased the levels of inflammatory factors, promoted the flora metabolism product trimethylamine N-oxide (TMAO), and induced microbial disorder in adult mice. Importantly, CRP extract mitigated these effects.

Conclusion

Taken together, these findings suggest that early-life AZT exposure increases the susceptibility to HFD-induced glycolipid metabolism disorder in adult mice, and CRP extract can decrease this susceptibility by regulating gut microbiome.

Development of organogel-based emulsions to enhance the loading and bioaccessibility of 5-demethylnobiletin

5-Demethylnobiletin (5-DMN), identified in the aged citrus peels, has received increasing attentions due to its outstanding bioactivity among citrus polymethoxyflavones (PMFs). However, the poor water solubility and high crystallinity limit its oral bioavailability. Besides, the solubility of 5-DMN in the oil is very limited, which restricts its loading capacity in emulsions for bioavailability enhancement. In this study, an organogel formulation was developed to improve the solubility of 5-DMN in medium-chain triacylglycerols by 3.5 times higher without crystal formation during 5-day storage at room temperature. Increasing the gelator (i.e., sugar ester) concentration led to the increase of viscosity and a gel-like structure of the organogel. The ternary phase diagram of organogel-based emulsions was explored, and 40% organogel was selected as the oil phase for emulsion preparation. Increasing the concentration of Tween 80 from 0% to 6% decreased the droplet size and viscoelasticity of the emulsions. Two in vitro models, the pH-stat lipolysis model and TNO gastro-intestinal model (TIM-1), were applied to investigate the bioaccessibility of 5-DMN in different delivery systems. Compared with the conventional emulsion and oil suspension, the pH-stat lipolysis demonstrated that the organogel-based emulsion was the most efficient tool to enhance 5-DMN bioacccessibility. Moreover, TIM-1 digestive study indicated that 5-DMN bioaccessibility delivered by organogel-based emulsions was about 3.26-fold higher than that of oil suspension. Our results suggested that the organogel-based emulsion was an effective delivery route to enhance the loading and bioaccessibility of lipophilic compounds of high crystallinity.