Anti-Obesity and Anti-Hyperglycemic Effects of Meretrix lusoria Protamex Hydrolysate in ob/ob Mice

A review: Interactions between protein from blue foods and functional components in delivery systems: Function exertion and transmembrane transport by in vitro digestion/cells model

Functional compounds (FCs) had some functions, which are affected easily by digestion and transmembrane transport leading to low absorption rates, such as lutein, quercetin, xylo-oligosaccharide. Protein from blue foods is a potential bioactive compound, which had higher bioavailability, especially for bioactive peptides (BBPs). The BBPs has great limitations, especially the variability under pepsin digestion. However, the limitation of single FCs and BBPs in bioavailability might can be complemented by mixture of different bioactive compounds. Therefore, this review provides an in-depth study on the function and mechanism of different FCs/BBPs and their mixtures. Specifically, digestion effect of mixtures on function and transmembrane transport mechanisms of different bioactive compounds were exhibited to elaborate interactions between BBPs and FCs in delivery systems (function and bioavailability). Combination of FCs/BBPs could enhance bioactive compounds function by mutual complement of function mechanisms, as well as improving the function after digestion by regulating digestion process. Moreover, transmembrane absorption and transport of FCs/BBPs also could be facilitated by mixtures due to complement of transmembrane mechanism (endocytosis, protein channels, cell bypass way). This manuscript lays a foundation for the development of active ingredient bioavailability in functional food processing.

Unravelling the complexities of non-alcoholic steatohepatitis: The role of metabolism, transporters, and herb-drug interactions

Nonalcoholic fatty liver disease (NAFLD) is a mainstream halting liver disease with high prevalence in North America, Europe, and other world regions. It is an advanced form of NAFLD caused by the amassing of fat in the liver and can progress to the more severe form known as non-alcoholic steatohepatitis (NASH). Until recently, there was no authorized pharmacotherapy reported for NASH, and to improve the patient's metabolic syndrome, the focus is mainly on lifestyle modification, weight loss, ensuring a healthy diet, and increased physical activity; however, the recent approval of Rezdiffra (Resmetirom) by the US FDA may change this narrative. As per the reported studies, there is an increased articulation of uptake and efflux transporters of the liver, including OATP and MRP, in NASH, leading to changes in the drug's pharmacokinetic properties. This increase leads to alterations in the pharmacokinetic properties of drugs. Furthermore, modifications in Cytochrome P450 (CYP) enzymes can have a significant impact on these properties. Xenobiotics are metabolized primarily in the liver and constitute liver enzymes and transporters. This review aims to delve into the role of metabolism, transport, and potential herb-drug interactions in the context of NASH.

Gastrointestinal digestion of food proteins: Anticancer, antihypertensive, anti-obesity, and immunomodulatory mechanisms of the derived peptides

Food proteins and their peptides play a significant role in the important biological processes and physiological functions of the body. The peptides show diverse biological benefits ranging from anticancer to antihypertensive, anti-obesity, and immunomodulatory, among others. In this review, an overview of food protein digestion in the gastrointestinal tract and the mechanisms involved was presented. As some proteins remain resistant and undigested, the multifarious factors (e.g. protein type and structure, microbial composition, pH levels and redox potential, host factors, etc.) affecting their colonic fermentation, the derived peptides, and amino acids that evade intestinal digestion are thus considered. The section that follows focuses on the mechanisms of the peptides with anticancer, antihypertensive, anti-obesity, and immunomodulatory effects. As further considerations were made, it is concluded that clinical studies targeting a clear understanding of the gastrointestinal stability, bioavailability, and safety of food-based peptides are still warranted.

Bioactive Peptides from Meretrix lusoria Enzymatic Hydrolysate as a Potential Treatment for Obesity in db/db Mice

Obesity is acknowledged as a significant risk factor for cardiovascular disease, often accompanied by increased inflammation and diabetes. Bioactive peptides derived from marine animal proteins show promise as safe and effective anti-obesity agents by regulating adipocyte differentiation through the AMPK signaling pathway. Therefore, this study aims to investigate the anti-obesity and anti-diabetic effects of bioactive compounds derived from a Meretrix lusoria Protamex enzymatic hydrolysate (MLP) fraction (≤1 kDa) through a 6-week treatment (150 mg/kg or 300 mg/kg, administered once daily) in leptin receptor-deficient db/db mice. The MLP treatment significantly decreased the body weight, serum total cholesterol, triglycerides, and LDL-cholesterol levels while also exhibiting a beneficial effect on hepatic and serum marker parameters in db/db mice. A histological analysis revealed a reduction in hepatic steatosis and epididymal fat following MLP treatment. Furthermore, poor glucose tolerance was improved, and hepatic antioxidant enzyme activities were elevated in MLP-treated mice compared to db/db control mice. Western blot analysis showed an increased expression of the AMPK protein after MLP treatment. In addition, the expression of lipogenic genes decreased in db/db mice. These findings indicate that bioactive peptides, which are known to regulate blood glucose levels, lipid metabolism, and adipogenesis, could be beneficial functional food additives and pharmaceuticals.

Hypolipidemic and Anti-Obesity Effect of Anserine on Mice Orally Administered with High-Fat Diet via Regulating SREBP-1, NLRP3, and UCP-1

To investigate the efficacy of anserine on antiobesity, C57BL/6 mice are orally administered with a high-fat diet (HFD) and different doses of anserine (60, 120, and 240 mg/kg/day) for 16 weeks. Body weight, lipid, and epididymal fat content in mice are measured, and their liver damage is observed. The results display that the body weight, epididymal fat content, and low-density lipoprotein cholesterol (LDL-C) content in anserine groups are decreased by 4.36-18.71%, 7.57-35.12%, and 24.32-44.40%, respectively. To further investigate the antiobesity mechanism of anserine, the expression of SREBP-1, NLRP3, NF-κB p65 (p65), and p-NF-κB p65 (p-p65) proteins in the liver and peroxisome proliferator-activated receptor gamma coactivator 1α (PGC1-α) and UCP-1 proteins in brown adipose tissue (BAT) is analyzed by Western blot. Results show that anserine can significantly decrease the expression of the NLRP3, p65, p-p65, and the SREBP-1 proteins and increase the expression of the PGC1-α and UCP-1 proteins. This study demonstrates that anserine lowered blood lipids and prevented obesity; its antiobesity mechanism may be related to the activation of brown fat by inflammation.

New Insights into Antioxidant Peptides: An Overview of Efficient Screening, Evaluation Models, Molecular Mechanisms, and Applications

Antioxidant peptides are currently a hotspot in food science, pharmaceuticals, and cosmetics. In different fields, the screening, activity evaluation, mechanisms, and applications of antioxidant peptides are the pivotal areas of research. Among these topics, the efficient screening of antioxidant peptides stands at the forefront of cutting-edge research. To this end, efficient screening with novel technologies has significantly accelerated the research process, gradually replacing the traditional approach. After the novel antioxidant peptides are screened and identified, a time-consuming activity evaluation is another indispensable procedure, especially in in vivo models. Cellular and rodent models have been widely used for activity evaluation, whilst non-rodent models provide an efficient solution, even with the potential for high-throughput screening. Meanwhile, further research of molecular mechanisms can elucidate the essence underlying the activity, which is related to several signaling pathways, including Keap1-Nrf2/ARE, mitochondria-dependent apoptosis, TGF-β/SMAD, AMPK/SIRT1/PGC-1α, PI3K/Akt/mTOR, and NF-κB. Last but not least, antioxidant peptides have broad applications in food manufacture, therapy, and the cosmetics industry, which requires a systematic review. This review introduces novel technologies for the efficient screening of antioxidant peptides, categorized with a new vision. A wide range of activity evaluation assays, encompassing cellular models, as well as rodent and non-rodent models, are provided in a comprehensive manner. In addition, recent advances in molecular mechanisms are analyzed with specific cases. Finally, the applications of antioxidant peptides in food production, therapy, and cosmetics are systematically reviewed.

Hyperglycemia effect of Pinctada martensii hydrolysate in diabetic db/db mice

ETHNOPHARMACOLOGICAL RELEVANCE

Pinctada martensii (Dunker) and other marine shellfish flesh have been traditionally used in China as folk remedies regulate blood sugar.

AIM OF THE STUDY

To investigate the main active constituents and the pharmacological mechanism of Pinctada martensii flesh enzymatic hydrolysate (PMH) against T2DM.

MATERIALS AND METHODS

The hypoglycemic activity of enzymolysis peptides from Pinctada martensii was evaluated by using db/db mice, through the influence of glycemic index, blood lipid and key protein expression of PI3K-Akt pathway. In addition, label-free quantitative proteomics was used to screen the key proteins for Pinctada martensii hydrolysate (PMH) to improve T2DM, and Western blot and qRT-PCR were used to verify the expression difference of differential proteins at protein and mRNA levels between different groups.

RESULTS

PMH were prepared and characterized. In vivo investigations revealed that the PMH could regulate blood glucose and improve glucose tolerance and insulin tolerance, reduced serum total cholesterol, triglyceride, low-density lipoprotein cholesterol levels and increase high-density lipoprotein cholesterol levels in db/db mice. Western blot results showed that PMH could up-regulate IRS-1, P-PI3K/PI3K and P-Akt/Akt levels in db/db mice. Label-free quantitative proteomic approach was used to analyze the proteome in db/db mouse liver, 231 proteins were reversed significantly (p < 0.05), and these proteins were involved in oxidative phosphorylation, glycolysis/gluconeogenesis and other pathways. Further screened 15 proteins with FC > 1.2 could be enriched in the retinol metabolic pathway, and the proteins in this pathway were also verified.

CONCLUSIONS

PMH has hypoglycemic effect and can be used as a potential natural T2DM intervener. The hypoglycemic activity of PMH is related to its regulation of the PI3K/AKT pathway. The PI3K/AKT pathway and the retinol pathway are considered as another potential pathway for PMH to exert hypoglycemic effects.

Antidiabetic Effect of Urolithin A in Cultured L6 Myotubes and Type 2 Diabetic Model KK-Ay/Ta Mice with Glucose Intolerance

Diabetes is caused by abnormal glucose metabolism, and muscle, the largest tissue in the human body, is largely involved. Urolithin A (UroA) is a major intestinal and microbial metabolite of ellagic acid and ellagitannins and is found in fruits such as strawberry and pomegranate. In this present study, we investigated the antidiabetic effects of UroA in L6 myotubes and in KK-Ay/Ta, a mouse model of type 2 diabetes (T2D). UroA treatment elevated the glucose uptake (GU) of L6 myotubes in the absence of insulin. This elevation in GU by UroA treatment was partially inhibited by the concurrent addition of LY294002, an inhibitor of phosphatidylinositol 3-kinase (PI3K) which activates Akt (PKB: protein kinase B) or Compound C, an inhibitor of 5'-adenosine monophosphate-activated protein kinase (AMPK). Moreover, UroA was found to activate both pathways of Akt and AMPK, and then to promote translocation of glucose transporter 4 (GLUT4) from the cytosol to the plasma membrane in L6 myotubes. Based on these in vitro findings, an intraperitoneal glucose tolerance test (IPGTT) was performed after the oral administration of UroA for 3 weeks to KK-Ay/Ta mice with glucose intolerance. UroA was demonstrated to alleviate glucose intolerance. These results suggest that UroA is a biofactor with antihyperglycemic effects in the T2D state.

The Effect of Phytochemicals and Food Bioactive Compounds on Diabetes

There are three main types of diabetes, namely, type 1 diabetes, type 2 diabetes (T2D), and diabetes in pregnancy (gestational diabetes) [...]

Anti-obesity effects of corn peptide on 3T3-L1 preadipocytes and C57BL/6J obese mice

Corn peptide (CP) is a small, natural, biologically active peptide obtained by protease-catalysed hydrolysis of corn. CP exerts antihypertensive, hypoglycaemic, antihyperlipidemic, antioxidant, and antitumor effects, as well as prevents cardiovascular and cerebrovascular diseases. Although CP plays a role in preventing obesity-related diseases, its role in reducing obesity has not yet been determined. In this study, we analysed the inhibitory effects of CP on lipid droplet accumulation in 3T3-L1 preadipocytes and high-fat diet (HFD)-induced C57BL/6J Obese Mice. The results show that CP could inhibit preadipocyte differentiation and oil accumulation in 3T3-L1 preadipocytes. Oral CP administration reduced serum triglyceride (TG) content, epididymal fat weight, abnormal liver fat droplet accumulation, and C/EBPα expression. Furthermore, combination of CP administration and exercise reduced body, liver, and adipose tissue weights; decreased serum total cholesterol (TC), triglyceride and low-density lipoprotein (LDL) levels; and inhibited hepatic lipid droplet accumulations and epididymal fat cell hypertrophy. Additionally, this combination inhibited the expression of transcription factors, C/EBPα, C/EBPβ, and PPARγ, and adipogenic factors, FABP4 in mice. In conclusion, oral administration of CP inhibited lipid droplet accumulation and counteracted HFD-induced obesity in mice.