Attenuated mTOR Signaling and Enhanced Glucose Homeostasis by Dietary Supplementation with Lotus Seedpod Oligomeric Procyanidins in Streptozotocin (STZ)-Induced Diabetic Mice

The interplay between probiotics and host autophagy: mechanisms of action and emerging insights

Autophagy, a lysosome-dependent protein degradation mechanism, is a highly conserved catabolic process seen in all eukaryotes. This cell protection system, which is present in all tissues and functions at a basic level, can be up- or downregulated in response to various stresses. A disruption in the natural route of the autophagy process is frequently followed by an interruption in the inherent operation of the body's cells and organs. Probiotics are live bacteria that protect the host through various mechanisms. One of the processes through which probiotics exert their beneficial effects on various cells and tissues is autophagy. Autophagy can assist in maintaining host homeostasis by stimulating the immune system and affecting numerous physiological and pathological responses. In this review, we particularly focus on autophagy impairments occurring in several human illnesses and investigate how probiotics affect the autophagy process under various circumstances.

A Metabolomics Study of the Effects of Eleutheroside B on Glucose and Lipid Metabolism in a Zebrafish Diabetes Model

(1) Background: Diabetes is a common metabolic disease that seriously endangers human health. In the present study, we investigated the therapeutic effects of the active ingredient Eleutheroside B (EB) from the traditional Chinese medicine Eleutheroside on diabetes mellitus in a zebrafish model. Concomitant hepatic injury was also analysed, along with the study of possible molecular mechanisms using metabolomics technology. This work should provide some theoretical references for future experimental studies. (2) Methods: A zebrafish diabetes model was constructed by soaking in a 1.75% glucose solution and feeding a high-fat diet. The intervention drug groups were metformin (100 μg∙mL-1) and EB (50, 100, and 150 μg∙mL-1) via water-soluble exposure for 30 days. Glucose, TG, TC, LDL-C, and HDL-C were evaluated in different treatment groups. GLUT4 protein expression was also evaluated in each group, and liver injury was observed by HE staining. Metabolomics techniques were used to investigate the mechanism by which EB regulates endogenous markers and metabolic pathways during the development of diabetes. (3) Results: All EB treatment groups in diabetic zebrafish showed significantly reduced body mass index (BMI) and improved blood glucose and lipid profiles. EB was found to upregulate GLUT4 protein expression and ameliorate the liver injury caused by diabetes. Metabolomics studies showed that EB causes changes in the metabolic profile of diabetic zebrafish. These were related to the regulation of purine metabolism, cytochrome P450, caffeine metabolism, arginine and proline metabolism, the mTOR signalling pathway, insulin resistance, and glycerophospholipid metabolism. (4) Conclusions: EB has a hypoglycaemic effect in diabetic zebrafish as well as significantly improving disorders of glycolipid metabolism. The mechanism of action of EB may involve regulation of the mTOR signalling pathway, purine metabolism, caffeine metabolism, and glycerophospholipid metabolism.

Animal protein hydrolysate reduces visceral fat and inhibits insulin resistance and hepatic steatosis in aged mice

BACKGROUND/OBJECTIVES

An increasing life expectancy in society has burdened healthcare systems substantially because of the rising prevalence of age-related metabolic diseases. This study compared the effects of animal protein hydrolysate (APH) and casein on metabolic diseases using aged mice.

MATERIALS/METHODS

Eight-week-old and 50-week-old C57BL/6J mice were used as the non-aged (YC group) and aged controls (NC group), respectively. The aged mice were divided randomly into 3 groups (NC, low-APH [LP], and high-APH [HP] and fed each experimental diet for 12 weeks. In the LP and HP groups, casein in the AIN-93G diet was substituted with 16 kcal% and 24 kcal% APH, respectively. The mice were sacrificed when they were 63-week-old, and plasma and hepatic lipid, white adipose tissue weight, hepatic glucose, lipid, and antioxidant enzyme activities, immunohistochemistry staining, and mRNA expression related to the glucose metabolism on liver and muscle were analyzed.

RESULTS

Supplementation of APH in aging mice resulted in a significant decrease in visceral fat (epididymal, perirenal, retroperitoneal, and mesenteric fat) compared to the negative control (NC) group. The intraperitoneal glucose tolerance test and area under the curve analysis revealed insulin resistance in the NC group, which was alleviated by APH supplementation. APH supplementation reduced hepatic gluconeogenesis and increased glucose utilization in the liver and muscle. Furthermore, APH supplementation improved hepatic steatosis by reducing the hepatic fatty acid and phosphatidate phosphatase activity while increasing the hepatic carnitine palmitoyltransferase activity. Furthermore, in the APH supplementation groups, the red blood cell (RBC) thiobarbituric acid reactive substances and hepatic H2O2 levels decreased, and the RBC glutathione, hepatic catalase, and glutathione peroxidase activities increased.

CONCLUSIONS

APH supplementation reduced visceral fat accumulation and alleviated obesity-related metabolic diseases, including insulin resistance and hepatic steatosis, in aged mice. Therefore, high-quality animal protein APH that reduces the molecular weight and enhances the protein digestibility-corrected amino acid score has potential as a dietary supplement for healthy aging.

Extraction Methods, Properties, Functions, and Interactions with Other Nutrients of Lotus Procyanidins: A Review

Lotus procyanidins, natural polyphenolic compounds isolated from the lotus plant family, are widely recognized as potent antioxidants that scavenge free radicals in the human body and exhibit various pharmacological effects, such as anti-inflammatory, anticancer, antiobesity, and hypoglycemic. With promising applications in food and healthcare, lotus procyanidins have attracted extensive attention in recent years. This review provides a comprehensive summary of current research on lotus procyanidins, including extraction methods, properties, functions, and interactions with other nutrient components. Furthermore, this review offers an outlook on future research directions, providing ideas and references for the exploitation and utilization of lotus.

Procyanidins: A promising anti-diabetic agent with potential benefits on glucose metabolism and diabetes complications

Diabetes mellitus (DM) is a complex disease with alarming worldwide health implications and high mortality rates, largely due to its complications such as cardiovascular disease, nephropathy, neuropathy, and retinopathy. Recent research has shown that procyanidins (PC), a type of flavonoid, have strong antioxidant and free radical elimination effects, and may be useful in improving glucose metabolism, enhancing pancreatic islet cell activity, and decreasing the prevalence of DM complications. This review article presents a systematic search for peer-reviewed articles on the use of PC in the treatment of DM, without any language restrictions. The article also discusses the potential for PC to sensitise DM medications and improve their efficacy. Recent in vivo and in vitro studies have demonstrated promising results in improving the biological activity and bioavailability of PC for the treatment of DM. The article concludes by highlighting the potential for novel materials and targeted drug delivery methods to enhance the pharmacokinetics and bioactivity of PC, leading to the creation of safer and more effective anti-DM medications in the future.

Proanthocyanidins may be potential therapeutic agents for the treatment of carotid atherosclerosis: A review

Atherosclerotic cerebrovascular disease is one of the major causes of death in China, with associated serious risk of disability and burden on society and families. Therefore, the development of active and effective therapeutic drugs for this disease is of great significance. Proanthocyanidins are a class of naturally occurring active substances, rich in hydroxyl groups and from a wide range of sources. Studies have suggested that they have a strong potential for anti-atherosclerosis activity. In this paper, we review published evidence regarding anti-atherosclerotic effects of proanthocyanidins in different atherosclerotic research models.

Natural bioactive compounds in Alzheimer's disease: From the perspective of type 3 diabetes mellitus

There is a close relationship between Alzheimer's disease (AD) and diabetes mellitus (DM), and the link between the two is often referred to as type 3 diabetes mellitus (T3DM). Many natural bioactive compounds have shown the potential to treat AD and diabetes. We mainly review the polyphenols represented by resveratrol (RES) and proanthocyanidins (PCs) and alkaloids represented by berberine (BBR) and Dendrobium nobile Lindl. alkaloids (DNLA) from the perspective of T3DM to review the neuroprotective effects and molecular mechanisms of natural compounds in AD.

Skeletal Muscle CSE Deficiency Leads to Insulin Resistance in Mice

Cystathionine-γ-lyase (CSE) is expressed in various tissues and generates H₂S via an alternative desulfuration reaction. We sought to explore the functions of skeletal muscle CSE using skeletal muscle conditional knockout CSE (MCSEKO) mice. It was found that body weight, muscle morphology, and exercise capacity were not altered in MCSEKO mice compared with littermate wild-type mice. RNA-seq-based transcriptome analysis showed that 275 genes were differentially regulated in skeletal muscle and multiple signaling pathways including insulin signaling and mTOR, PI3K-AKT, and cGMP-PKG signaling pathways were enriched in MCSEKO mice. The intraperitoneal glucose tolerance test and insulin tolerance test showed that glucose tolerance and insulin sensitivity were reduced in MCSEKO mice. Glucose transporter 4 (GLU4) and PKG-1 expression levels and insulin receptor substrate-1(IRS1)/PI3K/Akt signaling pathway were downregulated whilst the mTOR/S6K/S6 pathway was enhanced in MCSEKO mice. These effects were reversed by the H₂S supplement. Aerobic treadmill training significantly promoted glucose tolerance and insulin sensitivity and improved GLU4 and PKG-1 levels, promoted IRS1/PI3K/Akt signaling and suppressed mTOR/S6K/S6 signaling pathway in MCSEKO mice. Our data suggest that skeletal muscle CSE/H₂S signaling is critical for the maintenance of insulin sensitivity, which is associated with maintaining the balance in PKG, PI3K/Akt, and mTOR/S6K/S6 signaling pathways in skeletal muscle.

Effects of lotus seedpod oligomeric procyanidins on the inhibition of AGEs formation and sensory quality of tough biscuits

The advanced glycation end products (AGEs) are formed in baked products through the Maillard reaction (MR), which are thought to be a contributing factor to chronic diseases such as heart diseases and diabetes. Lotus seedpod oligomeric procyanidins (LSOPC) are natural antioxidants that have been added to tough biscuit to create functional foods that may lower the risk of chronic diseases. The effect of LSOPC on AGEs formation and the sensory quality of tough biscuit were examined in this study. With the addition of LSOPC, the AGEs scavenging rate and antioxidant capacity of LSOPC-added tough biscuits were dramatically improved. The chromatic aberration (ΔE) value of tough biscuits containing LSOPC increased significantly. Higher addition of LSOPC, on the other hand, could effectively substantially reduced the moisture content, water activity, and pH of LSOPC toughen biscuits. These findings imply that using LSOPC as additive not only lowers the generation of AGEs, but also improves sensory quality of tough biscuit.

Phytochemicals, biological activity, and industrial application of lotus seedpod (Receptaculum Nelumbinis): A review

Lotus (Nelumbo nucifera Gaertn.) is a well-known food and medicinal plant. Lotus seedpod (Receptaculum Nelumbinis) is the by-products during lotus products processing, which is considered as waste. Numerous studies have been conducted on its phytochemicals, biological activity and industrial application. However, the information on lotus seedpod is scattered and has been rarely summarized. In this review, summaries on preparation and identification of phytochemicals, the biological activities of extracts and phytochemicals, and applications of raw material, extracts and phytochemicals for lotus seedpod were made. Meanwhile, the future study trend was proposed. Recent evidence indicated that lotus seedpods extracts, obtained by non-organic and organic solvents, possessed several activities, which were influenced by extraction solvents and methods. Lotus seedpods were rich in phytochemicals categorized as different chemical groups, such as proanthocyanidins, oligomeric procyanidins, flavonoids, alkaloids, terpenoids, etc. These phytochemicals exhibited various bioactivities, including ameliorating cognitive impairment, antioxidation, antibacterial, anti-glycative, neuroprotection, anti-tyrosinase and other activities. Raw material, extracts and phytochemicals of lotus seedpods could be utilized as sources for biochar and biomass material, in food industry and as dye. This review gives well-understanding on lotus seedpod, and provides theoretical basis for its future research and application.

Bioactive Components in Whole Grains for the Regulation of Skeletal Muscle Function

Skeletal muscle plays a primary role in metabolic health and physical performance. Conversely, skeletal muscle dysfunctions such as muscular dystrophy, atrophy and aging-related sarcopenia could lead to frailty, decreased independence and increased risk of hospitalization. Dietary intervention has become an effective approach to improving muscle health and function. Evidence shows that whole grains possess multiple health benefits compared with refined grains. Importantly, there is growing evidence demonstrating that bioactive substances derived from whole grains such as polyphenols, γ-oryzanol, β-sitosterol, betaine, octacosanol, alkylresorcinols and β-glucan could contribute to enhancing myogenesis, muscle mass and metabolic function. In this review, we discuss the potential role of whole-grain-derived bioactive components in the regulation of muscle function, emphasizing the underlying mechanisms by which these compounds regulate muscle biology. This work will contribute toward increasing awareness of nutraceutical supplementation of whole grain functional ingredients for the prevention and treatment of muscle dysfunctions.

Beneficial Effects of Flavonoids on Skeletal Muscle Health: A Systematic Review and Meta-Analysis

Skeletal muscle (SkM) is a highly dynamic tissue that responds to physiological adaptations or pathological conditions, and SkM mitochondria play a major role in bioenergetics, regulation of intracellular calcium homeostasis, pro-oxidant/antioxidant balance, and apoptosis. Flavonoids are polyphenolic compounds with the ability to modulate molecular pathways implicated in the development of mitochondrial myopathy. Therefore, it is pertinent to explore its potential application in conditions such as aging, disuse, denervation, diabetes, obesity, and cancer. To evaluate preclinical and clinical effects of flavonoids on SkM structure and function. We performed a systematic review of published studies, with no date restrictions applied, using PubMed and Scopus. The following search terms were used: "flavonoids" OR "flavanols" OR "flavones" OR "anthocyanidins" OR "flavanones" OR "flavan-3-ols" OR "catechins" OR "epicatechin" OR "(-)-epicatechin" AND "skeletal muscle." The studies included in this review were preclinical studies, clinical trials, controlled clinical trials, and randomized-controlled trials that investigated the influence of flavonoids on SkM health. Three authors, independently, assessed trials for the review. Any disagreement was resolved by consensus. The use of flavonoids could be a potential tool for the prevention of muscle loss. Their effects on metabolism and on mitochondria function suggest their use as muscle regulators.

Modulation of the PI3K/Akt/mTOR signaling pathway by probiotics as a fruitful target for orchestrating the immune response

The mammalian target of rapamycin (mTOR) and the phosphatidylinositol-3-kinase (PI3K)/protein kinase B or Akt (PKB/Akt) signaling pathways are considered as two but somewhat interconnected significant immune pathways which play complex roles in a variety of physiological processes as well as pathological conditions. Aberrant activation of PI3K/Akt/mTOR signaling pathways has been reported to be associated in a wide variety of human diseases. Over the past few years, growing evidence in in vitro and in vivo models suggest that this sophisticated and subtle cascade mediates the orchestration of the immune response in health and disease through exposure to probiotics. An expanding body of literature has highlighted the contribution of probiotics and PI3K/Akt/mTOR signaling pathways in gastrointestinal disorders, metabolic syndrome, skin diseases, allergy, salmonella infection, and aging. However, longitudinal human studies are possibly required to verify more conclusively whether the investigational tools used to understand the regulation of these pathways might provide effective approaches in the prevention and treatment of various disorders. In this Review, we summarize the experimental evidence from recent peer-reviewed studies and provide a brief overview of the causal relationship between the effects of probiotics and their metabolites on the components of PI3K/Akt/mTOR signaling pathways and human disease.

Dietary xylo-oligosaccharide ameliorates colonic mucus microbiota penetration with restored autophagy in interleukin-10 gene-deficient mice

BACKGROUND

Inflammatory bowel disease (IBD) is, nowadays, highly prevalent and presents a global clinical challenge. The objective of this study is to assess the effects of xylo-oligosaccharide (XOS) on Il10^-/- mice, a classic animal model of IBD.

METHODS

Male wild-type (WT) mice were assigned to WT group, and Il10^-/- mice were assigned to interleukin-10 gene-deficient (IL-10-KO) group and XOS group, respectively. There were 6-8 mice aged 8 weeks in each group. Mice in the XOS group received 1.0 g/kg/day XOS by gavage for 4 weeks.

RESULTS

Compared with mice in IL-10-KO group, Il10^-/- mice with XOS intervention presented significant mild spontaneous colitis with lower disease activity index, histological scores, and bowel inflammatory cytokine levels. Dietary XOS downregulated bowel mucus bacterial penetration, which occurred as early as the onset of bowel colitis. The effect of XOS was associated with restored expression of LC3II/I and decreased expression of p62 and beclin-1 in colon.

CONCLUSIONS

Therefore, XOS decreases colonic mucus microbiota penetration with restored function of antophagy. Our findings suggest that XOS may be a potential dietary supplement or functional food for early management of IBD.

Therapeutic Targets for Phenolic Compounds from Agro-industrial Byproducts against Obesity

BACKGROUND

Obesity is considered as a global epidemic worldwide. This disorder is associated to several health effects such as metabolic disturbances that need both prevention and treatment actions. In this sense, bioactive secondary metabolites can be obtained from cheap sources such as agro-industrial waste providing a sustainable alternative against obesity. Among these secondary metabolites, phenolic compounds present a common chemical structure core with different substitutions that provides them biological properties such as antioxidant, inflammatory, anti-aging capacities.

OBJECTIVE

The aim of this review is to compile anti-obesity therapeutic targets for phenolic compounds from agro-industrial byproducts.

METHOD

Scientific information has been obtained from different databases such as Scopus, PubMed and Google Scholar in order to select the available full text studies in last years.

RESULTS

This review shows that peel, seed, pomace and other byproducts from agro-industry have different effects inhibiting enzymes related to lipid or glucose metabolism and modulating biomarkers, genes and gut microbiota in animal models.

CONCLUSION

Revalorizing actions of agro-industrial byproducts in the prevention or treatment of obesity or associated disorders can be considered to develop new high value products that act on lipid, glucose and energy metabolisms, oxidative stress, inflammation, adipose tissue or gut microbiota. However, further human studies are need in order to stablish the optimal administration parameters.

Grape seed proanthocyanidins reduced the overweight of C57BL/6J mice through modulating adipose thermogenesis and gut microbiota

Activating the thermogenic function of adipocytes is an attractive therapeutic strategy against obesity and its associated metabolic complications. Proanthocyanidins are a class of polyphenols which are widely found in plants and daily foods. This aim of this study is to investigate the modulatory effects of grape seed proanthocyanidin extract (GSPE) on brown adipose tissue (BAT) activity, browning of white adipose tissue (WAT) and microbiome regulation in high-fat diet (HFD)-fed mice and its associated molecular mechanism. An 8-week administration of GSPE at 200 mg per kg bw in mice significantly reduced their final body weight, antagonized their HFD-induced insulin resistance and elevated their levels of adiponectin and leptin, respectively (p < 0.05). GSPE significantly increased the expression levels of thermogenic marker UCP1 in BAT and elevated the expression of a key transcription factor of browning, PRDM16, and thermogenic markers UCP1 and PGC-1α in inguinal white adipose tissue (iWAT). The high doses of GSPE also increased the levels of acetic acid, propionic acid and butyric acid in the colon of HFD-fed mice (p < 0.05). Furthermore, GSPE normalized the colonic Firmicutes/Bacteroidetes ratios, reversed the relative abundance of Weissella, Faecalibaculum, Bacteroides, Akkermansia and Ruminococcus 1 induced by HFD, and improved the structural diversity of the gut microbiota in C57BL/6J mice.

Effect of lotus seedpod oligomeric procyanidins on AGEs formation in simulated gastrointestinal tract and cytotoxicity in Caco-2 cells

This study explored the effects of lotus seedpod oligomeric procyanidins (LSOPC) and their main monomer catechin (CC) on the formation of advanced glycation end products (AGEs) and Caco-2 cytotoxicity during gastrointestinal digestion. Studies have found that LSOPC and CC inhibited the AGEs formation effectively in simulated gastrointestinal digestion and protected Caco-2 cells from AGEs attack. The effect of CC on the inhibition of AGEs formation was significantly better than that of LSOPC. Further, they could effectively inhibit the digestive enzyme activity, reactive oxygen species, RAGE-p38MAPK-NF-κB signaling pathway, inflammatory factors (tumor necrosis factor alpha, interleukin 6), and adhesion factors (intercellular cell adhesion molecule-1, vascular cell adhesion molecule-1) to protect Caco-2 cells.

Src homolog and collagen homolog1 isoforms in acute and chronic liver injuries

Src homolog and collagen homolog (SHC) proteins are adaptor proteins bound to cell surface receptors that play an important role in signal transduction and related diseases. As an important member of the SHC protein family, SHC1 regulates cell proliferation and apoptosis, reactive oxygen species (ROS) production, and oxidative stress. Three isomeric proteins namely, p46shc, p52shc, and p66shc, are produced from the same SHC1 gene locus. All the three proteins are found in the liver, and are widely expressed in various hepatic cells. SHC1 has been proven to be associated with acute and chronic liver injuries of different etiologies, and plays important roles in liver fibrosis and hepatocellular carcinoma (HCC). Therefore, this review summarizes recent studies that discuss and explore the role of SHC1 in the occurrence and progression of liver diseases. We also provide a theoretical basis for future studies.

Hawthorn polyphenols reduce high glucose-induced inflammation and apoptosis in ARPE-19 cells by regulating miR-34a/SIRT1 to reduce acetylation

Diabetic retinopathy is a major complication in patients with diabetes. Herein, we investigate how hawthorn polyphenol extract (HPE) affects high glucose-induced oxidation, inflammation, and apoptosis in ARPE-19 cells. HPLC-MS/MS was used to determine HPE content and composition. Reactive oxygen species (ROS) production was assessed using fluorescence microscopy, while glucose-induced gene and protein expressions were analyzed using real-time PCR and western blotting in cells transfected with miR-34a mimics. We found that treating cells with 10 μg/ml of HPE, 30 μM procyanidin B2, chlorogenic acid, epicatechin, or resveratrol (positive control) significantly reduced ROS production and decreased apoptosis and inflammation-related factors (p < .01). Moreover, the expression level of SIRT1 was increased, while that of acetylated NF-κB p65 and p53 proteins was decreased. These data suggest that HPE can inhibit oxidative damage, inflammation, and apoptosis through the AMPK/SIRT1/NF-κB pathway, and decrease miR-34a/SIRT1/p53 pathway activation in ARPE-19 cells, thereby demonstrating a potential use as a food additive to mitigate hyperglycemia-induced retinal damage. PRACTICAL APPLICATIONS: Hawthorn polyphenol extract (HPE) significantly reduced ROS levels, apoptosis, and the expression of inflammation-related factors in ARPE-19 cells. HPE also inhibited the AMPK/SIRT1/NF-κB and miR-34a/SIRT1/p53 pathways, which are involved in hyperglycemia-induced inflammation and apoptosis of ARPE-19 cells by regulating acetylation. Thus, HPE, as a potential food additive, may mitigate hyperglycemia-induced retinal damage.

Diabetes diminishes a typical metabolite of litchi pericarp oligomeric procyanidins (LPOPC) in urine mediated by imbalanced gut microbiota

Animal studies and clinical trials have shown that dietary polyphenols and polyphenol-rich foods can reduce the risk of type 2 diabetes (T2D) and its complications, but how diabetes regulates the metabolism of polyphenol has not been fully elucidated. This study investigated the effects of diabetes on litchi pericarp oligomeric procyanidin (LPOPC) dynamic metabolism and its major static metabolites in urine. First, a high-fat and streptozotocin (STZ)-induced diabetic Sprague Dawley (SD) rat model was established. In the diabetic rat model, elevated fasting blood glucose, severely impaired glucose tolerance test, and increased reactive oxygen species (ROS) levels in serum and the liver were observed. Subsequently, 200 mg per kg body weight of LPOPC was administrated to control and diabetic SD rats, and the gastrointestinal tract was collected at 0.5 h, 1 h, 3 h, and 6 h. The results showed that the retention time of LPOPC was not changed in our diabetic rat model. However, the gut microbiota were significantly altered, with elevated Proteobacteria and Verrucomicrobia abundance in diabetic rats and decreased short chain fatty acid (SCFA)-producing bacteria. Interestingly, after one dose of 300 mg per kg body weight LPOPC, the total antioxidant capacity of urine in diabetic rats significantly decreased. We then tested the static metabolites of LPOPC, demonstrating that epicatechin had not changed in urine in diabetic rats, but that shikimic acid was significantly reduced in urine in diabetic rats. The changes in shikimic acid may be due to the alteration of gut microbiota and elevated ROS levels in serum.

Flavonoids Identification and Pancreatic Beta-Cell Protective Effect of Lotus Seedpod

Oxidative stress is highly associated with the development of diabetes mellitus (DM), especially pancreatic beta-cell injury. Flavonoids derived from plants have caused important attention in the prevention or treatment of DM. Lotus seedpod belongs to a traditional Chinese herbal medicine and has been indicated to possess antioxidant, anti-age, anti-glycative, and hepatoprotective activities. The purpose of this study was to demonstrate the pancreatic beta-cell protective effects of lotus seedpod aqueous extracts (LSE) against oxidative injury. According to HPLC/ESI-MS-MS method, LSE was confirmed to have flavonoids derivatives, especially quercetin-3-glucuronide (Q3G). In vitro, LSE dose-dependently improved the survival and function of rat pancreatic beta-cells (RIN-m5F) from hydrogen peroxide (H₂O₂)-mediated loss of cell viability, impairment of insulin secretion, and promotion of oxidative stress. LSE showed potential in decreasing the H₂O₂-induced occurrence of apoptosis. In addition, H₂O₂-triggered acidic vesicular organelle formation and microtubule-associated protein light chain 3 (LC3)-II upregulation, markers of autophagy, were increased by LSE. Molecular data explored that antiapoptotic and autophagic effects of LSE, comparable to that of Q3G, might receptively be mediated via phospho-Bcl-2-associated death promoter (p-Bad)/B-cell lymphoma 2 (Bcl-2) and class III phosphatidylinositol-3 kinase (PI3K)/LC3-II signal pathway. In vivo, LSE improved the DM symptoms and pancreatic cell injury better than metformin, a drug that is routinely prescribed to treat DM. These data implied that LSE induces the autophagic signaling, leading to protect beta-cells from oxidative stress-related apoptosis and injury.

Allicin-induced host-gut microbe interactions improves energy homeostasis

Allicin (diallylthiosulfinate) is a natural food compound with multiple biological and pharmacological functions. However, the mechanism of beneficial role of Allicin on energy homeostasis is not well studied. Gut microbiota (GM) profoundly affects host metabolism via microbiota-host interactions and coevolution. Here, we investigated the interventions of beneficial microbiome induced by Allicin on energy homeostasis, particularly obesity, and related complications. Interestingly, Allicin treatment significantly improved GM composition and induced the most significant alteration enrichment of Bifidobacterium and Lactobacillus. Importantly, transplantation of the Allicin-induced GM to HFD mice (AGMT) played a remarkable role in decreasing adiposity, maintaining glucose homeostasis, and ameliorating hepatic steatosis. Furthermore, AGMT was effective in modulating lipid metabolism, activated brown adipose tissues (BATs), induced browning in sWAT, reduced inflammation, and inhibited the degradation of intestinal villi. Mechanically, AGMT significantly increased Blautia [short-chain fatty acids (SCFAs)-producing microbiota] and Bifidobacterium in HFD mice, also increased the SCFAs in the cecum, which has been proved many beneficial effects on energy homeostasis. Our study highlights that Allicin-induced host-gut microbe interactions plays an important role in regulating energy homeostasis, which provides a promising potential therapy for obesity and metabolic disorders based on host-microbe interactions.

Oligomeric Procyanidin Nanoliposomes Prevent Melanogenesis and UV Radiation-Induced Skin Epithelial Cell (HFF-1) Damage

The potential protective effect of nanoliposomes loaded with lotus seedpod oligomeric procyanidin (LSOPC) against melanogenesis and skin damaging was investigated. Fluorescence spectroscopy showed that, after encapsulation, the LSOPC-nanoliposomes still possessed strong inhibitory effects against melanogenesis, reducing the activity of both monophenolase and diphenolase. Molecular docking indicated that LSOPC could generate intense interactive configuration with tyrosinase through arene-H, arene-arene, and hydrophobic interaction. An ultraviolet radiated cell-culture model (human foreskin fibroblast cell (HFF-1)) was used to determine the protective effects of the LSOPC-nanoliposomes against skin aging and damage. Results showed that LSOPC-nanoliposomes exerted the highest protective effects against both ultraviolet B (UVB) and ultraviolet A (UVA) irradiation groups compared with non-encapsulated LSOPC and a control (vitamin C). Superoxide dismutase (SOD) and malonaldehyde (MDA) assays demonstrated the protection mechanism may be related to the anti-photooxidation activity of the procyanidin. Furthermore, a hydroxyproline assay suggested that the LSOPC-nanoliposomes had a strong protective effect against collagen degradation and/or synthesis after UVA irradiation.

Antihyperglycemic effect of rice husk derived xylooligosaccharides in high-fat diet and low-dose streptozotocin-induced type 2 diabetic rat model

Rice husk (RH) is an agricultural waste obtained from rice milling process. Our previous study demonstrated the optimized process of extracting xylooligosaccharides (XOS), a prebiotic that can support the growth and activity of beneficial gut microbiota, from RH. Accumulated evidences indicate that the composition of gut microbiota is involved in the progression of insulin resistance and diabetes. This study aims to evaluate the antihyperglycemic effect and putative mechanisms of RH-XOS using a diabetic rat model induced by high-fat diet and streptozotocin injection. Diabetic rats were randomly assigned to receive vehicle (DMC), XOS (DM-XOS), metformin (DMM), and a combination of XOS and metformin (DMM-XOS). An additional group of rats were fed with normal diet plus vehicle (NDC) and normal diet plus XOS (ND-XOS). Supplementation with RH-XOS for 12 weeks successfully decreased the fasting plasma glucose, insulin, leptin, and LPS levels in DM-XOS compared with DMC. Likewise, the insulin-stimulated glucose uptake assessed by in vitro study was significantly enhanced in DM-XOS, DMM, and DMM-XOS. The diminished protein expressions of GLUT4 and pAktSer473 as well as pAMPKThr172 were significantly modulated in DM-XOS, DMM, and DMM-XOS groups. Interestingly, RH-XOS supplementation reversed the changed gut permeability, elevated the number of beneficial bacteria, both Lactobacillus and Bifidobacterium spp., and increased SCFAs production. Taken together, the results confirm the efficacy of RH-XOS in achieving good glycemic control in diabetes by maintenance of gut microbiota and attenuation of endotoxemia. The findings reveal the benefits of RH-XOS and open an opportunity to improve its value by its development as a nutraceutical for diabetes.

Lotus Seedpod Extracts Reduced Lipid Accumulation and Lipotoxicity in Hepatocytes

Non-alcoholic fatty liver disease (NAFLD) is closely associated with metabolic disorders, including hepatic lipid accumulation and lipotoxicity. Plant-derived polyphenols have attracted considerable attention in the prevention of NAFLD. Lotus seedpod, rich in polyphenols, is a traditional Chinese herbal medicine. Previous studies have showed that lotus seedpod possess radioprotective, antioxidant, anti-cancer, and anti-inflammatory activities. In this study, the in vitro hepatoprotective effect of lotus seedpod extract (LSE) and its main component epigallocatechin (EGC) was examined. Firstly, oleic acid (OA), an unsaturated fatty acid, was used to induce the phenotype of NAFLD in human hepatocytes, HepG2 cells. LSE dose-dependently improved the OA-induced viability loss of HepG2 cells. Non-cytotoxic concentrations of LSE or EGC abolished intracellular lipid accumulation and oxidative stress in the OA-treated cells. In addition, LSE and EGC showed a minor effect on autophagy, and potential in reducing OA-induced occurrence of apoptosis confirmed by morphological and biochemical features, including an increase in the formation of apoptotic bodies, the exposure of phosphatidylserine, and activation of caspases. Molecular data showed the anti-apoptotic effect of LSE might be mediated via downregulation of the mitochondrial pathway. Our data imply that EGC-enriched LSE potentially could be developed as an anti-NAFLD agent.

Lotus seedpod proanthocyanidin-whey protein complexes: Impact on physical and chemical stability of β-carotene-nanoemulsions

The impact of lotus seedpod proanthocyanidin (LSPC) on the functional properties of β-carotene-loaded whey-protein stabilized nanoemulsions was investigated. LSPC was selected because it is known to exhibit strong antioxidant activity, as well as having various health benefits. Physically stable nanoemulsions containing small anionic droplets (d < 0.15 μm; ζ = -27 mV) could be formed at pH 6.5 using whey protein-LSPC complexes as natural emulsifiers. The physical and chemical stabilities of the nanoemulsions were then measured when they were incubated at different pH values. LSPC addition promoted droplet aggregation at pH 4, but not at pH 3, 6.5, or 8, which was mainly attributed to its ability to reduce the electrostatic repulsion between the lipid droplets at pH 4. LSPC was shown to have stronger antioxidant activity than catechin and epicatechin. Our results show that the chemical stability of β-carotene nanoemulsions could be considerably improved by adding LSPC. We believe that LSPC-whey protein complexes can be used as effective emulsifiers and antioxidants in nutraceutical-loaded nanoemulsions, which may be useful for developing more efficacious functional foods and beverages.

Activating Effects of Phenolics from Apache Red Zea mays L. on Free Fatty Acid Receptor 1 and Glucokinase Evaluated with a Dual Culture System with Epithelial, Pancreatic, and Liver Cells

The aim was to characterize a phenolic-rich water extract from the pericarp of an improved genotype of Apache red maize (RPE) and evaluate its ability to activate the type 2 diabetes markers free fatty acid receptor 1 (GPR40) and glucokinase (GK) in vitro. The extract contained mainly phenolic acids, anthocyanins, and other flavonoids. RPE inhibited α-amylase (IC₅₀ = 88.3 μg/mL), α-glucosidase (IC₅₀ = 169.3 μg/mL), and reduced glucose transport in a Caco-2 cell monolayer (up to 25%). Furthermore, RPE activated GPR40 (EC₅₀ = 77.7 μg/mL) in pancreatic INS-1E cells and GK (EC₅₀ = 43.4 μg/mL) in liver HepG2 cells, potentially through allosteric modulation. RPE activated GPR40-related insulin secretory pathway and activated the glucose metabolism regulator AMPK (up to 78%). Our results support the hypothesis that foods with a high concentration of anthocyanins and phenolic acids, such as in the selected variety of maize used, could ameliorate obesity and type 2 diabetes comorbidities.

Oligomer Procyanidins from Lotus Seedpod Regulate Lipid Homeostasis Partially by Modifying Fat Emulsification and Digestion

Dietary polyphenols have shown hypolipidemic effects by reducing triglyceride absorption. The mechanisms may involve modifying fat emulsion during digestion in the gastrointestinal tract and suppressing lipase during hydrolysis in the small intestine. In an in vivo study, lotus seedpod oligomeric procyanidin (LSOPC) decreased total serum triglyceride and total cholesterol and elevated the high-density lipoprotein level in the hyperlipidemic rat model. In addition, LSOPC suppressed de novo lipogenesis-related gene expressions. In an in vitro study, the LSOPC-enriched emulsion decreased the mean droplet size from 0.36 to 0.33 μm and increased the viscosity of the emulsion. Moreover, the LSOPC-enriched emulsion improved the antioxidant properties. A digestion model was developed and showed that the particle size of the LSOPC-enriched emulsion increased in the oral cavity. However, an increase and then a significant drop of the particle size was measured in the stomach and small intestine. The free fatty acid release rate was decreased in the LSOPC-enriched emulsion partly ascribed to the inhibition of lipase by LSOPC.

Procyanidin B2 from lotus seedpod regulate NO/ADMA/DDAH pathway to treat insomnia in rats

Recent studies show that nitric oxide/asymmetric dimethylarginine/dimethylarginine dimethylaminohydrolase (NO/ADMA/DDAH) pathway may contribute to the development of sleep disorder. The objective of this study was to explore the inhibitory effect of procyanidin B2 from lotus seedpod (LSPC), a naturally occurring catechin compound, on insomnia and the mechanisms involved. The experiments were performed in brain from Sprague-Dawley rat control and insomniac rats treated or not with LSPC (15, 30, and 45 mg/kg, intragastrically) for 7 days. LSPC treatment reduced walking time and forelimb lifting-up frequency, cerebral levels of noradrenaline, glutamic acid, ADMA, sleep latency, and 8-isoprostane; increased sleep duration, cerebral concentrations of 5-hydroxytryptamine, γ-aminobutyric acid, and NO concomitantly with upregulated cerebral expression of DDAH 1, DDAH2, and neuronal NO synthases in insomniac rats. The present results suggest that LSPC may regulate NO/ADMA/DDAH pathway by inhibiting oxidative stress to treat insomnia in rats when sleep evaluation was achieved on the basis of behavioral criteria.

In Vitro and In Vivo Protective Effects of Flavonoid-Enriched Lotus Seedpod Extract on Lipopolysaccharide-Induced Hepatic Inflammation

Endotoxin lipopolysaccharide (LPS) plays an important role in the acceleration of hepatic inflammation. Natural medicinal plants that can prevent inflammation by targeting LPS have potential therapeutic clinical application. The aim of the study is to examine the anti-inflammatory effects of lotus seedpod extract (LSE), used as a traditional Chinese herbal medicine with hemostasis function and for eliminating bruise, on the LPS-induced hepatic inflammation and its underlying molecular mechanisms in vitro and in vivo. In vitro, LSE and its purified compound (-)-epigallocatechin (EGC) dose-dependently inhibited the expressions of pro-inflammatory cytokines and mediators, including tumor necrosis factor (TNF)- α , interleukin (IL)-6, cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS), without affecting cell viability in LPS-stimulated human hepatoma cell line HepG2. Molecular studies showed the anti-LPS effect of HLP or EGC might be mediated via downregulation of Toll-like receptor 4. (TLR4)-mediated both NF- κ B and p38 signaling, as demonstrated by the usage of pyrrolidine dithiocarbamate (PDTC), a specific NF- κ B inhibitor. In vivo, LPS-induced hepatic inflammation was significantly ameliorated in LSE-fed mice as gauged by dose-dependent inhibition of serum levels of biochemical markers of liver damage, the changes of hepatic lobular architecture and the secretion of pro-inflammatory mediators, as well as induction of anti-oxidant enzymes. As a result, our data presented the first evidence of EGC-enriched LSE as an anti-inflammatory agent in LPS-stimulated HepG2 cells and mice, and these findings may open interesting perspectives to the strategy in treatment for hepatic inflammation.

Luteolin, a natural flavonoid, inhibits methylglyoxal induced apoptosis via the mTOR/4E-BP1 signaling pathway

Methylglyoxal (MG) accumulation has been observed in human cerebrospinal fluid and body tissues under hyperglycaemic conditions. Recent research has demonstrated that MG-induces neuronal cell apoptosis, which promotes the development of diabetic encephalopathy. Our previous animal study has shown that luteolin, a natural flavonoid, attenuates diabetes-associated cognitive dysfunction. To further explore the neuroprotective properties of luteolin, we investigated the inhibitive effect of luteolin on MG-induced apoptosis in PC12 neuronal cells. We found that MG inhibited cell viability in a dose-dependent manner and induced apoptosis in PC12 cells. Pretreatment with Luteolin significantly elevated cell viability, reduced MG-induced apoptosis, inhibited the activation of the mTOR/4E-BP1 signaling pathway, and decreased pro-apoptotic proteins, Bax, Cytochrome C as well as caspase-3. Furthermore, we found that pretreatment with the mTOR inhibitor, rapamycin, significantly reduced the expression of the pro-apoptotic protein Bax. Therefore, these observations unambiguously suggest that the inhibitive effect of Luteolin against MG-induced apoptosis in PC12 cells is associated with inhibition of the mTOR/4E-BP1 signaling pathway.