Ameliorating effects of goby fish protein hydrolysates on high-fat-high-fructose diet-induced hyperglycemia, oxidative stress and deterioration of kidney function in rats

High-fat and carbohydrate diet caused chronic kidney damage by disrupting kidney function, caspase-3, oxidative stress and inflammation

The study aimed to compare the effects of a diet rich in fat, carbohydrates and protein on rat kidneys. The study was conducted on 40 Wistar albino rats bred at İnönü University Faculty of Medicine after the approval of the ethics committee. Rats were randomly divided into 4 groups: Control group, and the groups where the animals were fed with high carbohydrate, fat and protein rich feed. After the applications, the rat kidney tissues were removed by laparoscopy under anesthesia and blood samples were collected. 13 weeks long fat-rich and carbohydrate feed application had negative effects on oxidant-antioxidant balance, oxidative stress index, inflammation markers, kidney functions tests, histopathology and immunohistochemistry caspase-3 findings in rat kidney tissues, especially in the carbohydrate group when compared to the controls. Protein-rich feed, there were no significant difference in biochemical and histopathology compared to the control group. Fat and carbohydrate rich feed led to an increase in oxidative stress in rat kidney tissues. Oxidative stress led to nephrotoxicity, which in turn led to chronic kidney tissue damages. A more balanced and protein-rich diet instead of excessive sugar and fatty food intake could be suggested to prevent chronic kidney damage.

Effects of diets supplemented with bioactive peptides on nutrient digestibility, immune cell responsiveness, and fecal characteristics, microbiota, and metabolites of adult cats

Bioactive peptides (BP) are recognized for their ability to function as antioxidants and maintain lipid stability. They may have positive health effects, including antihypertensive, anti-inflammatory, antimicrobial, osteoprotective, gut health, and immunomodulatory properties, but are poorly tested in cats. Our primary objective was to determine the apparent total tract digestibility (ATTD) of BP-containing kibble diets and assess how the fecal characteristics, metabolites, and microbiota were affected in adult cats. Our secondary objective was to test whether BP could impact blood oxidative stress markers and cytokine concentrations following transport stress. Twelve adult cats (4.83 ± 0.37 yr; 4.76 ± 0.14 kg) were used in a replicated 4 × 4 Latin square design to test four extruded kibble diets: Control (no BP), Chicken (4% chicken BP), Marine1 (2% marine BP), and Marine2 (4% marine BP). Each experimental period lasted 28 d, with a 20-d adaptation phase, 5 d for fecal collection, 2 d for blood collection, and 1 d for transport stress testing (driven in vehicle in individual carriers for 45 min). Salivary cortisol and blood oxidative stress markers and cytokines were measured after transport. Fecal microbiota data were evaluated using 16S rRNA gene amplicon sequencing and QIIME2. All other data were analyzed using the Mixed Models procedure of SAS, with P < 0.05 being considered significant and P < 0.10 considered trends. No differences were observed in animal health outcomes, with all cats remaining healthy and serum metabolites remaining within reference ranges. Cats fed the Marine2 diet had higher (P < 0.05) ATTD of dry matter (84.5% vs. 80.9%) and organic matter (88.3% vs. 85.8%) than those fed the control diet. The ATTD of protein and energy tended to be higher (P < 0.10) for cats fed the Marine2 diet. Fecal characteristics, metabolites, and bacterial alpha and beta diversity measures were not affected by treatment. However, the relative abundances of six bacterial genera were different (P < 0.05) and two bacterial genera tended to be different (P < 0.10) across treatments. Treatment did not alter salivary cortisol, blood oxidative stress markers, or blood cytokines after transport stress. Our data suggest that BP inclusion may increase nutrient digestibility and modify fecal microbiota and immune measures. More testing is required, however, to determine whether BP may provide additional benefits to cats.

Oxidative stress in animal models of obesity caused by hypercaloric diets: A systematic review

Obesity is a global health difficulty characterized by an excessive accumulation of fat that increases body weight. Obesity has been studied in multiple animal models, of which those in which it is induced by diet stand out. Due to the increase in this condition, other mechanisms have been addressed that are triggered by states of overweight or obesity, such as the appearance of oxidative stress. These models aim to relate obesity caused by diet and how it influences the development of oxidative stress. In this study, a systematic review of the literature of 39 articles that studied obesity due to the consumption of hypercaloric diets and the appearance of oxidative stress in different animal models was carried out. This review identified the models with the most excellent use and the characteristics of the most appropriate diets to characterize states of oxidative stress due to obesity. In addition, the advantages and disadvantages of each model used are provided, as well as the techniques used for the assessment of obesity, and oxidative stress, providing the information in such a way that there is a general overview of the existing models of the parameters that allow to adequately establish both variables studied, providing information that allows the researcher to choose the appropriate model and factors according to the interest and objectives of the present research.

Hypoglycaemic Molecules for the Management of Diabetes Mellitus from Marine Sources

Diabetes mellitus (DM) is a chronic metabolic disorder recognized as a major health problem globally. A defective insulin activity contributes to the prevalence and expansion of DM. Treatment of DM is often hampered by limited options of conventional therapies and adverse effects associated with existing procedures. This has led to a spike in the exploration for potential therapeutic agents from various natural resources for clinical applications. The marine environment is a huge store of unexplored diversity of chemicals produced by a multitude of organisms. To date, marine microorganisms, microalgae, macroalgae, corals, sponges, and fishes have been evaluated for their anti-diabetic properties. The structural diversity of bioactive metabolites discovered has shown promising hypoglycaemic potential through in vitro and in vivo screenings via various mechanisms of action, such as PTP1B, α-glucosidase, α-amylase, β-glucosidase, and aldose reductase inhibition as well as PPAR alpha/gamma dual agonists activities. On the other hand, hypoglycaemic effect is also shown to be exerted through the balance of antioxidants and free radicals. This review highlights marine-derived chemicals with hypoglycaemic effects and their respective mechanisms of action in the management of DM in humans.

Vitamin D3 alleviates nonalcoholic fatty liver disease in rats by inhibiting hepatic oxidative stress and inflammation via the SREBP-1-c/ PPARα-NF-κB/IR-S2 signaling pathway

Introduction: Nonalcoholic fatty liver disease (NAFLD) is a chronic disease characterized by fat deposits in liver cells, which can lead to hepatitis and fibrosis. This study attempted to explore the protective effect of vitamin D3 (VitD) against NAFLD. Methods: Adult male albino rats were randomized into four separate groups: the negative control group was fed a standard rat chow; the positive group received a high-fat diet (20%) and 25% fructose water (NAFLD); the VitD control group was intramuscularly treated with VitD (1,000 IU/kg BW) 3 days per week for 10 weeks; and the NAFLD group was treated with VitD therapy. Biochemical and hepatic histological analyses were performed. Hepatic oxidative stress and inflammatory conditions were also studied. Hepatic expression of sterol regulatory element-binding protein 1-c (SREBP-1-c), peroxisome proliferator-activated receptor alpha (PPAR-α), and insulin receptor substrate-2 was analyzed by quantitative real-time polymerase chain reaction. Results and discussion: The NAFLD rats exhibited elevated terminal body weight, hepatic injury markers, dyslipidemia, glucose intolerance, and insulin resistance. Moreover, the NAFLD rats had increased SREBP-1-c expression and reduced PPAR-α and IRS-2 expressions. Histological analysis showed hepatic steatosis and inflammation in the NAFLD group. In contrast, VitD administration improved the serum biochemical parameters and hepatic redox status in NAFLD rats. Also, VitD treatment ameliorated hepatic inflammation and steatosis in the NAFLD group by decreasing the expression of SREBP-1-c and increasing the expression of PPAR-α. Overall, these results suggest that VitD could have a protective effect against NAFLD and its associated complication.

Antidiabetic effects of protein hydrolysates from Trachinotus ovatus and identification and screening of peptides with α-amylase and DPP-IV inhibitory activities

In the present study, the antidiabetic properties of Trachinotus ovatus protein hydrolysates (TOH) in streptozotocin-induced diabetic mice were investigated, and peptides with α-amylase (AAM) and dipeptidyl peptidase IV (DPP-IV) inhibitory activities were identified and screened. The results showed that TOH alleviated body weight loss, polyphagia, blood glucose elevation and insulin secretion decline in diabetic mice. After 4 weeks of TOH administration, random blood glucose (RBG) decreased significantly. The TOH groups showed a dose-dependent reduction in fasting blood glucose (FBG), especially in the high-dose TOH group, which reduced FBG by 58% versus the effect of metformin. Moreover, TOH exerted a remarkable protective effect on hepatorenal function, as evidenced by increased superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX) and decreased serum urea levels. Histopathological studies confirmed that TOH can significantly protect the kidney and pancreas from histological changes, which was of great benefit for ensuring the normal secretion of insulin and preventing the occurrence of complications such as diabetic nephropathy. Two fractions with higher inhibitory activity against AAM and DPP-IV, F4 and F6, were obtained from the ultrafiltration of TOH-2 (≤3 kDa). A total of 19 potentially active peptides from F4 and 3 potentially active peptides from F6 were screened by LC‒MS/MS combined with bioinformatic analysis. These peptides are small molecular peptides composed of 2-6 amino acids, rich in characteristic amino acids such as proline, arginine, phenylalanine and asparagine, and contain high proportions of peptides (68% for F4, 67% for F6) with hydrophobicity ≥50%. They offer potent antidiabetic potential and could potentially bind to the active sites in the internal cavities of the target enzymes AAM and DPP-IV. In summary, this study revealed for the first time the antidiabetic effects of protein hydrolysates of Trachinotus ovatus and their derived peptides, which are promising natural ingredients with the potential to be used for the treatment or prevention of diabetes.

Low-molecular weight oligosaccharides from gum tragacanth (Astragalus gossypinus) ameliorate nonalcoholic fatty liver disease (NAFLD) in Wistar male rats

Non-alcoholic fatty liver disease (NAFLD) is the most common liver disease affecting 25% of the world's population. The effects of oligosaccharides from Gum tragacanth (Astragalus gossypinus) (GT) on oxidative stress, glucose metabolism, and expression of autophagy genes were investigated in induced non-alcoholic fatty liver. Twenty-four male healthy rats were divided into four groups, Control; high-fat diet, high-fat diet + 100 mg GT oligosaccharides/kg body weight, high-fat diet + 200 mg GT oligosaccharides/kg body weight and fed with the trial diets for 70 days. At the end of the experiment, the results indicated that GT oligosaccharides affected the weight gain and liver weight in NAFLD-induced rats. In addition, the results showed that the use of GT oligosaccharides significantly decreased oxidative stress, liver injury, and hyperglycemia (p < .05) and upregulated the expression of autophagy genes in NAFLD-induced rats.

Practical applications

Overall, the results of the current study demonstrated that the use of GT oligosaccharides obtained from Gum tragacanth (Astragalus gossypinus) showed significant antioxidant properties and hypoglycemia in NAFLD induced rats and could be used as a useful nutritional strategy for the prevention and treatment of NAFLD.

Ameliorating Effects of Bioactive Peptides Extracted from Litopenaeus vannamei Wastes on Oxidative Stress, Glucose Regulation, and Autophagy Gene Expression in Nonalcoholic Fatty Liver-Induced Rats

This study aimed to investigate the effect of bioactive peptides from Litopenaeus vannamei on oxidative stress, glucose regulation, and autophagy gene expression in the induced nonalcoholic fatty liver rats. Bioactive peptides used in the current study were extracted in a progressive rise in temperature (40–60°C) (GP). For this purpose, twenty-four healthy male rats (initial weight, 230.1 ± 22 g) were divided in four experimental groups including control (standard diet), HFD (high-fat diet), HFD + GP20, and 300 (high-fat diet + 20, 300 mg peptides/kg body weight). After 70 days, the results indicated that experimental treatments did not affect the body and liver weight (P > 0.05), although the higher liver weight was seen in HFD treatment. Based on these results, the use of GP peptides improved antioxidant enzymes and decreased MDA concentration, and a significant difference was observed between peptide treatments and HFD (P < 0.05). In comparison to the HFD group, significantly lower liver enzymes (ALT and AST) were seen in peptide treatments (P < 0.05). Also, the results indicated that the lowest amylase, alkaline phosphatase, glucose, insulin, HOMA-IR, and inflammation cytokines (TNF-ɑ and IL-6) were seen in peptide groups. The autophagy gene expression was measured in the liver cells, and the results showed that, unlike HFD treatment, the use of GP peptides decreased Beclin 1, Atg7, and P62 expression in male rat's livers. Overall, the results of the current study demonstrated that the use of GP peptides at low concentration shows significant hypoglycemia and antioxidant properties in nonalcoholic fatty liver-induced rats.

Microencapsulated bioactive peptides from brewer's spent grain promotes antihypertensive and antidiabetogenic effects on a hypertensive and insulin-resistant rat model

The effects of microcapsules containing brewer's spent grain (BSG) peptides were evaluated on a hypertensive/insulin-resistant rat model induced by a sucrose-rich diet (SRD) administration. Animals received for 100 days the control diet (CD), SRD, and CD and SRD diets supplemented with microencapsulated peptides (CD-P and SRD-P). During the experimental period, blood pressure was monitored. Glycemia, tissue glycogen content, nitric oxide, and the activity of enzymes related to hypertensive and diabetogenic mechanisms were determined. The consumption of SRD caused hypertensive and hyperglycemic effects compared to CD. However, the SRD-P group presented lower systolic pressure at the middle of ingestion, achieving similar values than the CD. The SRD-P rats decreased all enzymes' activities compared to the SRD reaching the values of CD, except for those of α-amylase in cecal content and DPP-IV in serum. It was possible to corroborate potential antihypertensive and antidiabetogenic in vivo effects of the microencapsulated BSG peptides. PRACTICAL APPLICATIONS: Brewer's spent grain (BSG) is the main waste obtained from brewing industry. Bioactive peptides obtained after an enzymatic hydrolysis of proteins with in vitro antihypertensive and antidiabetogenic activity have been described. However, to corroborate the action of these bioactive peptides, in vivo studies are necessary. In the present work, microcapsules containing bioactive peptides from BSG were administered on the rat model with induced hypertension and insulin-resistance, corroborating an in vivo antihypertensive and antidiabetogenic effects by inhibition of enzymes related with blood pressure regulation and glucose metabolism. This work demonstrated that microcapsules of BSG peptides could be included into functional foods formulations, or used as dietary supplement for improving health and the prevention of non-communicable diseases, adding value to the brewing process by-product.

Beneficial effects of fish and fish peptides on main metabolic syndrome associated risk factors: Diabetes, obesity and lipemia

The definition of metabolic syndrome (MetS) fairly varies from one to another guideline and health organization. Per description of world health organization, occurrence of hyperinsulinemia or hyperglycemia in addition to two or more factors of dyslipidemia, hypoalphalipoproteinemia, hypertension and or large waist circumference factors would be defined as MetS. Conventional therapies and drugs, commonly with adverse effects, are used to treat these conditions and diseases. Nonetheless, in the recent decades scientific community has focused on the discovery of natural compounds to diminish the side effects of these medications. Among many available bioactives, biologically active peptides have notable beneficial effects on the management of diabetes, obesity, hypercholesterolemia, and hypertension. Marine inclusive of fish peptides have exerted significant bioactivities in different experimental in-vitro, in-vivo and clinical settings. This review exclusively focuses on studies from the recent decade investigating hypoglycemic, hypolipidemic, hypercholesterolemic and anti-obesogenic fish and fish peptides. Related extraction, isolation, and purification methodologies of anti-MetS fish biopeptides are reviewed herein for comparison purposes only. Moreover, performance of biopeptides in simulated gastrointestinal environment and structure-activity relationship along with absorption, distribution, metabolism, and excretion properties of selected oligopeptides have been discussed, in brief, to broaden the knowledge of readers on the design and discovery trends of anti-MetS compounds.Supplemental data for this article is available online at https://doi.org/10.1080/10408398.2022.2052261 .

Enhanced Autophagic Flux, Suppressed Apoptosis and Reduced Macrophage Infiltration by Dasatinib in Kidneys of Obese Mice

Obesity causes renal changes (ORC), characterized by defective renal autophagy, lipogenesis, enhanced macrophage infiltration and apoptosis. We hypothesize that Dasatinib, a tyrosine kinase inhibitor, may ameliorate changes associated with obesity. We the mice with either Obesogenic diet (OD) or a standard basal diet. After 12 weeks, the mice received either vehicle or Dasatinib 4 mg/kg/d for an additional four weeks. We examined serum creatinine, urea, lipid profile and renal cortical mRNA expression for lipogenesis marker SREBP1, inflammatory macrophage marker iNOS and fibrosis markers; TGFβ and PDGFA genes; immunohistochemical (IHC) staining for CD68; inflammatory macrophage marker and ASMA; fibrosis marker, LC3 and SQSTM1/P62; autophagy markers and western blotting (WB) for caspase-3; and, as an apoptosis marker, LC3II/I and SQSTM1/P62 in addition to staining for H&E, PAS, Sirius red and histopathological scoring. Dasatinib attenuated renal cortical mRNA expression for SREBP1, iNOS, PDGFA and TGFβ and IHC staining for CD68, ASMA and SQSTM1/P62 and WB for caspase-3 and SQSTM1/P62, while elevating LC3 expression. Moreover, Dasatinib ameliorated ORC; glomerulosclerosis, glomerular expansion, tubular dilatation, vacuolation and casts; inflammatory cellular infiltration; and fibrosis. Dasatinib is a promising therapy for ORC by correcting autophagy impairment, attenuating lipogenesis, apoptosis and macrophage infiltration by inducing antifibrotic activity.

Using Collagen Peptides From the Skin of Monkfish (Lophius litulon) to Ameliorate Kidney Damage in High-Fat Diet Fed Mice by Regulating the Nrf2 Pathway and NLRP3 Signaling

Background

Oxidative stress and inflammation play important roles in high-fat diet (HFD) induced kidney damage. Previous studies show that the collagen extracted from the skin of monkfish (Lophius litulon) with pepsin (pepsin-solubilized collagen, PSC) exhibits good biological activities. This study investigates the protective effect of PSCP against chronic kidney injury in HFD-fed mice.

Methods

Pepsin-solubilized collagen was further hydrolyzed into collagen peptides, and the compound with the best 2,2-diphenyl-1-picrylhydrazyl (DPPH) clearance rate was named pepsin-solubilized collagen peptide (PSCP). A group of mice were fed an HFD for 4 weeks, and then for another 6 weeks PSCP was added to their diet at the amount of either 100 or 200 mg/kg.

Results

Pepsin-solubilized collagen peptide treatment (200 mg/kg) reduced the mice's serum levels of uric acid (UA), creatinine (CRE), and blood urea nitrogen (BUN) by 27, 20, and 37%, respectively. This treatment also remarkably improved renal histopathology. Moreover, the activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT) were increased by 96, 52, and 74%, respectively, and decreased the malondialdehyde (MDA) level by 36%. Additionally, PSCP activated the Nrf2 pathway and inhibited NLRP3 signaling to significantly reduce the levels of inflammatory cytokines IL-1β, IL-6, and TNF-α.

Conclusions

Our results indicate that compound PSCP has the potential to prevent or control chronic kidney damage.

Dietary Lactobacillus acidophilus ATCC 4356 Relieves the Impacts of Aflatoxin B1 Toxicity on the Growth Performance, Hepatorenal Functions, and Antioxidative Capacity of Thinlip Grey Mullet (Liza ramada) (Risso 1826)

Dietary Lactobacillus acidophilus ATCC 4356 was used to relieve the impacts of aflatoxin B₁ toxicity on the performances of Liza ramada. The control diet was without any additives, while the second and third diets were supplemented with aflatoxin B₁ at 0.5 and 1 mg/kg. The fourth diet was supplemented with Lb. acidophilus ATCC 4356 at 1 × 10⁶ CFU/mL per kg diet, while the fifth with aflatoxin B₁ at 1 mg/kg and Lb. acidophilus ATCC 4356 at 1 × 10⁶ CFU/mL per kg diet. The growth performance markedly increased (p < 0.05) in L. ramada fed Lb. acidophilus ATCC 4356, while aflatoxin B₁ at 0.5 and 1 mg/kg groups showed a severe reduction. The red blood cells, hemoglobulin, hematocrit, and white blood cells were markedly increased in L. ramada fed Lb. acidophilus ATCC 4356 while decreased (p < 0.05) in fish fed aflatoxin B₁ at 0.5 and 1 mg/kg. The blood total protein and albumin were markedly increased (p < 0.05) in L. ramada fed Lb. acidophilus ATCC 4356 while reduced in aflatoxin B₁ at 0.5 and 1 mg/kg groups. The levels of total cholesterol and triglycerides were meaningfully increased in fish of the Lb. acidophilus ATCC 4356 and aflatoxin B₁ at 1 mg/kg groups while decreased in aflatoxin B₁ at 0.5 and 1 mg/kg groups. Alanine aminotransferase, aspartate aminotransferase, creatinine, and urea levels were markedly decreased (p < 0.05) in fish-fed Lb. acidophilus ATCC 4356 while increased in aflatoxin B₁ at 0.5 and 1 mg/kg groups. The highest levels of blood glucose and cortisol were seen in fish contaminated with aflatoxin B₁ at 1 mg/kg, while the lowest levels were observed in the fish fed Lb. acidophilus ATCC 4356 group (p < 0.05). The catalase and superoxide dismutase were markedly enhanced in the Lb. acidophilus ATCC 4356 group and severely declined in aflatoxin B₁ at 0.5 and 1 mg/kg groups (p < 0.05). The malondialdehyde level was markedly reduced in fish fed Lb. acidophilus ATCC 4356 with or without aflatoxin B₁ at 1 mg/kg diets while increased in fish contaminated with aflatoxin B₁ at 0.5 and 1 mg/kg (p < 0.05). The control group had lower malondialdehyde levels than the aflatoxin B₁ at 1 mg/kg group and higher than the Lb. acidophilus ATCC 4356 with or without aflatoxin B₁ toxicity (p < 0.05). Histopathological examination revealed impaired intestines and livers in fish contaminated with aflatoxin B₁ while Lb. acidophilus ATCC 4356 relieves the inflammation and protected the intestines and livers. In conclusion, dietary Lb. acidophilus ATCC 4356 is recommended to relieve the impacts of aflatoxicosis-induced hepatorenal failure and oxidative stress in L. ramada.

Protease Catalyzed Production of Spent Hen Meat Hydrolysate Powder for Health Food Applications

Whole spent hen meat of Indian commercial layer bird (BV-300 breed) was enzymatically hydrolyzed using Flavourzyme® derived from Aspergillus oryzae. Different time, temperature, and pH combinations generated through response surface methodology (RSM) were tested to find the optimal hydrolysis condition at which maximum antioxidant potential and degree of hydrolysis can be achieved. Hydrolysis for 30 min at a temperature of 53.9°C and pH of 6.56 was found suitable for achieving high degree of hydrolysis and antioxidant activity. Antioxidant potential at optimized conditions was estimated at 93.26% by DPPH radical scavenging assay and 2.32 mM TEAC by FRAP assay. Amino acid profiling of the hydrolysate correlated very well with SDS-PAGE profiling. SDS-PAGE results confirmed that 30 min hydrolysis time was enough to produce low molecular weight peptides (2–5 kDa) with high antioxidant potential. Antioxidant rich Indian spent hen meat hydrolysate powder was economically produced using spray drying. Sensory analysis revealed that 10% hydrolysate powder had satisfactory overall acceptability and has potential to be used in health/functional foods at this concentration. This is the first study wherein optimum hydrolysis conditions for Indian spent hen meat have been reported.

Effects of Gundelia tournefortii L. on biochemical parameters, antioxidant activities and DNA damage in a rat model of experimental obesity

The present study was designed to investigate the effects of Gundelia tournefortii L. plant extract on different tissues in terms of DNA damage, biochemical and antioxidant parameter values in rats with high-calorie diets. With this aim, Wistar albino male rats were divided into 4 groups containing 6 rats each and the study was completed over 12 weeks duration. At the end of the implementation process over the 12 weeks, rats were sacrificed and blood and tissue samples were obtained. Analyses were performed on blood and tissue samples. According to results for DNA damage (8-OHdG), in brain tissue the OG2 group was significantly reduced compared to the NC group. For MDA results in liver tissue, OG1 and OG2 groups were determined to increase by a significant degree compared to the control group, while the OG2 group was also increased significantly compared to the obese group. In terms of the other parameters, comparison between the groups linked to consumption of a high calorie diet (HCD) and administration of Gundelia tournefortii L. in terms of antioxidant activities and serum samples obtained statistically significant results. Gundelia tournefortii L. plant extracts had effects that may be counted as positive on antioxidant parameter activity and were especially identified to improve DNA damage and MDA levels in brain tissues. Additionally, consumption of Gundelia tournefortii L. plant extract in the diet may have antiobesity effects; thus, it should be evaluated for use as an effective weight-loss method and as a new therapeutic agent targeting obesity.

Fish protein hydrolysates as a health-promoting ingredient-recent update

Dietary habits and lifestyle-related diseases indicate that food has a direct impact on individual health. Hence, a diet containing essential nutrients is important for healthy living. Fish and fish products are important in diets worldwide because of their nutritional value, especially their easily digestible proteins with essential amino acids. Similarly, fish protein hydrolysate (FPH) obtained from fish muscle and by-products has been reported to exhibit various biological activities and to have functional properties, which make FPH a suitable nutraceutical candidate. This review focuses on the health-promoting ability of FPH in terms of skin health, bone and cartilage health, blood lipid profile, and body-weight management studied in rats and human model systems. The absorption and bioavailability of FPH in humans is discussed, and challenges and obstacles of FPH as a functional food ingredient are outlined.

Developments for Collagen Hydrolysate in Biological, Biochemical, and Biomedical Domains: A Comprehensive Review

The collagen hydrolysate, a proteinic biopeptide, is used for various key functionalities in humans and animals. Numerous reviews explained either individually or a few of following aspects: types, processes, properties, and applications. In the recent developments, various biological, biochemical, and biomedical functionalities are achieved in five aspects: process, type, species, disease, receptors. The receptors are rarely addressed in the past which are an essential stimulus to activate various biomedical and biological activities in the metabolic system of humans and animals. Furthermore, a systematic segregation of the recent developments regarding the five main aspects is not yet reported. This review presents various biological, biochemical, and biomedical functionalities achieved for each of the beforementioned five aspects using a systematic approach. The review proposes a novel three-level hierarchy that aims to associate a specific functionality to a particular aspect and its subcategory. The hierarchy also highlights various key research novelties in a categorical manner that will contribute to future research.

Effect of Opuntia dejecta (Salm-Dyck) flowers in liver of fructose-fed rats: Biochemicals, enzymatic and histological studies

Phytochemical composition and antioxidant activity of flowers decoction at post-flowering stage (F3D) of Opuntia dejecta were determined. The obtained findings demonstrate that F3D has a marked antioxidant activity in all tested assays. Furthermore, the present study was designed to test the protective activity of F3D against induced Diabetes type 2 (DT2) in male rats. Those metabolic syndromes were induced by a high-fructose diet (HFD) (10% fructose solution) for a period of 20 weeks. F3D was administered orally (100 and 300 mg/kg body weight) daily for the last 4 weeks. Metformin (150 mg/kg body weight) was used as a standard drug and administrated orally for the last 4 weeks. The results showed a significant increase in blood glucose, triglycerides and hepatic markers (ALAT, ASAT and ALK-P) in HFD group. A significant increase in hepatic TBARS and a significant decrease in SOD, CAT and GP_X were observed in fructose fed rats compared to control group. Administration of F3D showed a protective effect in biochemical and oxidative stress parameters measured in this study. Also, oral administration of F3D restored the histological architecture of rat liver in comparison with rats fed HFD. In conclusion, F3D attenuated hepatic oxidative stress in fructose-fed rats.

Deteriorating insulin resistance due to WL15 peptide from cysteine and glycine-rich protein 2 in high glucose-induced rat skeletal muscle L6 cells

This study investigates the antioxidant and antidiabetic activity of the WL15 peptide derived from Channa striatus on regulating the antioxidant property in the rat skeletal muscle cell line (L6) and enhancing glucose uptake via glucose metabolism. Increased oxidative stress plays a major role in the development of diabetes and its complications. Strategies are needed to mitigate the oxidative stress that can reduce these pathogenic processes. Our results showed that with treatment with WL15 peptide, the reactive oxygen species significantly decreased in L6 myotubes in a dose-dependent manner, and increased antioxidant enzymes help to prevent the formation of lipid peroxidation in L6 myotubes. The cytotoxicity of WL15 is evaluated in the L6 cells and found to be non-cytotoxic at the tested concentration. Also, for the analysis of glucose uptake activity in L6 cells, the 2-(N-[7-nitrobenz-2-oxa-1,3-diazol-4-yl]amino)-2-deoxy- d -glucose assay was performed in the presence of wortmannin and genistein inhibitors. WL15 demonstrated antidiabetic activities through a dose-dependent increase in glucose uptake (64%) and glycogen storage (7.8 mM). The optimal concentration for the maximum activity was found to be 50 µM. In addition, studies of gene expression in L6 myotubes demonstrated upregulation of antioxidant genes and genes involved in the pathway of insulin signaling. In cell-based assays, WL15 peptide decreased intracellular reactive oxygen species levels and demonstrated insulin mimic activity by enhancing the primary genes involved in the insulin signaling pathway by increased glucose uptake indicating that glucose transporter type 4 (GLUT4) is regulated from the intracellular pool to the plasma membrane.

Gamma-aminobutyric acid regulates glucose homeostasis and enhances the hepatopancreas health of juvenile Chinese mitten crab (Eriocheir sinensis) under fasting stress

The ability of immune defense and resistance to physiological stress is crucial to animal health and survival. This study investigated the regulation of γ-aminobutyric acid (GABA) on metabolic homeostasis and its enhancement of hepatopancreas health in juvenile Chinese mitten crab (Eriocheir sinensis) under food deprivation. Juvenile crabs of 400 individuals were divided into four treatment groups: a control group without injection, and injections with a phosphate-buffered saline solution, 100 μmol GABA/mL and 1000 μmol GABA/mL, respectively. Hypoglycemia was induced by fasting, whereas the GABA treatment regulated hemolymph glucose homeostasis. The quantitative real-time PCR (qRT-PCR) results showed that the GABA treatment significantly up-regulated the mRNA expression levels of crustacean hyperglycemic hormone (CHH) and pyruvate kinase (PK). In contrast, the expression of E. sinensis insulin-like peptide (EsILP) was significantly down-regulated in the cranial ganglia, thoracic ganglia and hepatopancreas. Moreover, acid phosphatase (ACP), alkaline phosphatase (AKP), aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activities were significantly increased in the hepatopancreas by the GABA treatment. Furthermore, the hemocyanin content in serum was significantly increased with the GABA injection, and the glutathione (GSH) content, total superoxide dismutase (T-SOD) activity and catalase (CAT) activity in the hepatopancreas showed a similar increasing trend with the dose elevation of GABA. Therefore, these results indicate that GABA can effectively maintain the hemolymph glucose homeostasis by regulating the levels of glucose metabolism-related hormones and key enzymes to promote the degradation and utilization of hepatopancreas glycogen. Meanwhile, GABA can improve the hepatopancreas function and immune status of juvenile E. sinensis under fasting stress. The treatment with GABA may provide a clue to guide health management in crab farming.

Anti-diabetic effects of pomegranate extracts in long-term high fructose-fat fed rats

Background

A high-sugar or/and high-fat diets is a major risk factors for obesity. However, increased fruit and vegetable intake has been recently linked to obesity prevention. The aim of the present study was to investigate the preventive effects of pomegranate leaves (PL), juice (PJ) and peel (PP) extracts, on insulin resistance and oxidative stress in high fat and high fructose diet-induced obese rats.

Methods

Obesity in rats was induced by consumption of diet high in saturated fat and fructose (HFD) for a long period (12 weeks).

Results

Compared to the control group (CG) fed chow died, the high fat and high fructose diet (HFD) group showed a significant increase in the fasted plasma levels of glucose (29.8%), insulin (45%), amylase (70%) and lipase (54%). Moreover, HFD feeding has increased lipid peroxidation and protein carbonylation and decreased antioxidant enzymes levels. However, PL, PJ and PP treatment markedly prevents glucose intolerance, insulin resistance and oxidative stress and decrease amylase and lipase levels.

Conclusion

These findings highlight that a long-term intake of pomegranate extracts might be a potential alternative strategy for the prevention of a HFD induced insulin resistance and oxidative stress.

Development of delivery system based on marine chitosan: Encapsulationand release kinetic study of antioxidant peptides from chitosan microparticle

The present work aims to encapsulate goby fish protein hydrolysate (GPH), endowed with antioxidant activity, through ionic gelation process using blue crab chitosan (CH) and tripolyphosphate anions and to evaluate the structural, thermal and antioxidant properties of the elaborated microparticles (MPs). The GPH-loaded MPs present spherical shape as seen by scanning electron microscopy (SEM) images and positive zeta potential. The increase of loaded GPH concentration led to the increase of encapsulation efficiency (EE) and to the reduction of the particle size. In fact, MPs, loaded with 2 and 5 mg/ml GPH, had EE values of 44 and 58% and mean particles size of 4.81 and 3.78 μm, respectively. Furthermore, thermogravimetric analysis (TGA) profiles revealed the enhanced thermal stability of encapsulated biopeptides compared to the free ones. Release kinetic data showed a Fickian diffusion behavior which follows swelling and a diffusion-controlled mechanism for peptides liberation. Finally, as opposed to unloaded MPs, an improvement of the antioxidant activity of the loaded MPs with biopeptides was observed.

Protein Recovery from Underutilised Marine Bioresources for Product Development with Nutraceutical and Pharmaceutical Bioactivities

The global demand for dietary proteins and protein-derived products are projected to dramatically increase which cannot be met using traditional protein sources. Seafood processing by-products (SPBs) and microalgae are promising resources that can fill the demand gap for proteins and protein derivatives. Globally, 32 million tonnes of SPBs are estimated to be produced annually which represents an inexpensive resource for protein recovery while technical advantages in microalgal biomass production would yield secure protein supplies with minimal competition for arable land and freshwater resources. Moreover, these biomaterials are a rich source of proteins with high nutritional quality while protein hydrolysates and biopeptides derived from these marine proteins possess several useful bioactivities for commercial applications in multiple industries. Efficient utilisation of these marine biomaterials for protein recovery would not only supplement global demand and save natural bioresources but would also successfully address the financial and environmental burdens of biowaste, paving the way for greener production and a circular economy. This comprehensive review analyses the potential of using SPBs and microalgae for protein recovery and production critically assessing the feasibility of current and emerging technologies used for the process development. Nutritional quality, functionalities, and bioactivities of the extracted proteins and derived products together with their potential applications for commercial product development are also systematically summarised and discussed.

Tilapia Skin Peptides Ameliorate Diabetic Nephropathy in STZ-Induced Diabetic Rats and HG-Induced GMCs by Improving Mitochondrial Dysfunction

Diabetic nephropathy (DN) is one of the major microvascular complications of diabetes, and mitochondrial dysfunction has been observed in the kidneys of diabetic patients. Tilapia skin peptides (TSPs) are mixtures of small-molecular-weight peptides derived from tilapia skin. Rising evidence suggests that bioactive peptides from marine sources are beneficial for DN. This study aimed to investigate whether TSPs can alleviate the pathological progress in experimental DN by improving mitochondrial dysfunction through the activation of Bnip3/Nix signaling. In the current study, TSPs treatment alleviated the metabolic parameters and renal morphology in streptozotocin-induced diabetic rats. Additionally, TSPs treatment significantly activated Bnip3/Nix signaling and improved the mitochondrial morphology, reversed the over-production of mitochondrial superoxide and cellular reactive oxygen species and the decreased mitochondrial membrane potential, thereby inhibiting the expressions of fibronectin, collagen IV and intercellular cell adhesion molecule-1 in glomerular mesangial cells induced by high glucose. Collectively, our results suggest that TSPs show the renoprotective effect on DN by improving mitochondrial dysfunction, and they can be a potential therapeutic strategy for DN.

Furcellaran-Coated Microcapsules as Carriers of Cyprinus carpio Skin-Derived Antioxidant Hydrolysate: An In Vitro and In Vivo Study

Carp skin gelatine hydrolysate (CSGH) may be a possible bioactive peptide source, as promising antioxidant properties have been noted during in vivo testing. Hence, the present study focused on improving the bioavailability of the antioxidant peptides from CSGH and on the use of furcellaran (FUR), which can protect the biopeptides during digestion in the gastrointestinal tract. Therefore, in this study, microcapsules coated with furcellaran and containing CSGH cores were prepared. The structural properties of the sample were determined using FT-IR and SEM analysis. The antioxidant properties of hydrolysate, uncoated, and encapsulated samples were investigated. In vivo analysis included determination of its safety in an animal organism and evaluation of the lipid profile, antioxidant blood status, and mRNA expression of some genes involved in antioxidant status in Wistar rats. The results showed no adverse effects of microencapsulated protein hydrolysates in laboratory animals. Nonetheless, there was a statistically significant rise in the level of total antioxidant status blood serum among animals consuming CSGH and not inducing oxidative stress. This can be viewed as a promising indication of the positive effects of antioxidant properties tested in vivo. The process of CSGH microencapsulation in FUR cause a decrease in antioxidant hydrolysate activity, both in vitro, as well as in healthy Wistar rats. When considering the results of the presented diverse therapeutic potential, further research on CSGH being a potential bioactive peptide source used as a functional food or nutraceutical, but with a different microencapsulation coating, is encouraged.

Preparation of bioactive peptides with antidiabetic, antihypertensive, and antioxidant activities and identification of α-glucosidase inhibitory peptides from soy protein

In this study, the peptides of soy protein obtained by enzymatic digestion with proteases were analyzed for their antidiabetic, antihypertensive, and antioxidant activities. Peptides prepared with alkaline proteinase (AP) exhibited the highest α-glucosidase inhibitory activity compared with those from papain and trypsin digestion. AP hydrolysates also exhibited dipeptidyl peptidase IV (DPP-IV) inhibitory, angiotensin-converting enzyme (ACE) inhibitory, and antioxidant activities. Gastrointestinal digestion of peptides enhanced α-glucosidase, DPP-IV, and ACE inhibitory activities compared with AP hydrolysates. AP peptides showing highest α-glucosidase inhibitory activity were purified by anion-exchange and size-exclusion chromatography， and identified using tandem MS. We found three novel α-glucosidase inhibitory peptides with sequences LLPLPVLK, SWLRL, and WLRL with IC50 of 237.43 ± 0.52, 182.05 ± 0.74, and 162.29 ± 0.74 μmol/L, respectively. Therefore, peptides hydrolyzed from soy protein are promising natural ingredients for nutraceutical applications assisting in the management of diabetes.

RNase1 alleviates the Aeromonas hydrophila-induced oxidative stress in blunt snout bream

RNase1 is an enzyme important in host defense in vertebrates where it degrades the RNA of bacteria and viruses. We evaluated the effect of RNase1 on the resistance to Aeromonas hydrophila infection in Megalobrama amblycephala. The fish were randomly divided into four groups: a blank group (none-treated M. amblycephala), a control group (injected PBS), a challenge group (A. hydrophila-injected) and a treatment group (pre-treated with RNase1 24 h before the A. hydrophila injection), and we collected five tissues of each group. Then we recorded changes in the levels of glutathione (GSH), oxidized glutathione (GSSG), hepatic catalase (CAT), superoxide dismutase (SOD), malondialdehyde (MDA) and lysozyme; and the relative mRNA expression of catalase (CAT), selenium-dependent glutathione peroxidase (GPx), Cu/Superoxide dismutase (Cu/Zn-SOD), glutamate-cysteine ligase (GCLC), glutathione reductase (GR) and nuclear factor erythroid 2-related factor 2 (Nrf2) for four groups. The expression of six genes was highest in liver and blood of the blank group. It was significantly higher in the gut of the treatment group (compared to control and challenge groups) 12 h after the infection. The treatment group exhibited a significant increase in GSH, SOD and CAT activity, and a decrease in GSSG, MDA and lysozyme content (compared to the control and challenge groups) 6 and 12 h after infection. These results suggest that supplementation with RNase1 protein can enhance resistance against A. hydrophila infections in M. amblycephala.

Recently isolated antidiabetic hydrolysates and peptides from multiple food sources: a review

Diabetes, a metabolic syndrome of global importance has been on a progressive rise in recent years. Several pharmacological approaches have been made, which have proved effective, but with underlying side effects. Bioactive hydrolysates (BHs) and peptides (BPs) from food sources, however, have shown the relative advantage of imparting less adverse effects. Furthermore, BHs and BPs from food have been discovered to impart their antidiabetic potentials through one or more mechanisms such as inhibition of digestive enzymes, inhibition of the antigenic enzyme - Dipeptyl peptidase IV (DPP-IV), decrease in blood glucose levels and increase in insulin uptake. Several plants and animal sources have been used as protein sources for the isolation of antidiabetic hydrolysates and peptides through different mechanisms and analytical techniques. This review integrates recent research information about several popular and unconventional food sources of BHs and BPs, their isolation techniques, antidiabetic effects and protein profiles. In addition, the fractionation technique(s) employed in each study and inhibition potentials of BHs and BPs are reviewed. This article is intended to supplement accessible scholarly literature and intellectual awareness on the subject of food-oriented approach for the management of diabetes.

Bioactive properties: enhancement of hepatoprotective, antioxidant and DNA damage protective effects of golden grey mullet protein hydrolysates against paracetamol toxicity

This study was undertaken to examine the hepatoprotective, antioxidant, and DNA damage protective effects of protein hydrolysates from Liza aurata, against paracetamol overdose induced liver injury in Wistar rats. L. aurata protein hydrolysates (LAPHs) were mainly constituted by glutamic acid (Glu) and glutamine (Gln) and lysine (Lys). In addition, they contained high amounts of proline (Pro), leucine (Leu) and glycine (Gly). The molecular weight distribution of the hydrolysates was determined by size exclusion chromatography, which analyzed a representative hydrolysate type with a weight range of 3–20 kDa. The hepatoprotective effect of LAPHs against paracetamol liver toxicity was investigated by in vivo assay. Rats received LAPHs daily by gavage, for 45 days. Paracetamol was administrated to rats during the last five days of treatment by intraperitoneal injection. Paracetamol overdose induced marked liver damage in rats was noted by a significant increase in the activities of serum aspartate amino transferase (AST) and alanine amino transferase (ALT), and oxidative stress which was evident from decreased activity of the enzymatic antioxidants (superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx)), and level of glutathione (GSH), and increased concentration of lipid peroxidation products (MDA). Furthermore, paracetamol increased the DNA damage with liver histopathological changes. LAPH pretreatment significantly attenuated paracetamol-induced hepatotoxic effects, including oxidative damage, histopathological lesions, and apoptotic changes in the liver tissue. Interestingly, LAPHs restored the activities of antioxidant enzymes and the level of GSH, ameliorated histological and molecular aspects of liver cells. The present data suggest that paracetamol high-dose plays a crucial role in the oxidative damage and genotoxicity of the liver and therefore, some antioxidants such us LAPHs might be safe as hepatoprotectors. Altogether, our studies provide consistent evidence of the beneficial effect of LAPHs on animals treated with a toxic dose of paracetamol and might encourage clinical trials.

This study was undertaken to examine the hepatoprotective, antioxidant, and DNA damage protective effects of protein hydrolysates from Liza aurata, against paracetamol overdose induced liver injury in Wistar rats.

Protective effects of thornback ray muscle protein hydrolysate against dyslipidemia, oxidative stress and reduced fertility induced by high cholesterol diet in adult male rats

Enzymatic thornback ray (Raja clavata) muscle hydrolysates have been shown to have antioxidant and antihypertensive activities in vitro. The Neutrase hydrolysate exhibited the highest activities, so it was investigated along with the undigested muscle to test their hypolipidemic, antioxidative and fertility effects in rats fed with a high-cholesterol diet (HCD). Animals were allocated into four groups of 5 rats each: a normal diet group (control), a HCD group, and two groups of HCD with a daily dose of undigested muscle (Und) or the hydrolysate (MH) at 0.7 g kg⁻¹ of body weight. All animals received their respective treatments daily for 1 month. After the treatment period, serum lipid profiles, the activities of alanine aminotransferase and aspartate aminotransferase, the level of malonaldehyde, the activities of antioxidant enzymes (catalase and glutathione peroxidase) in the liver and sperm fertility parameters (in the epididymis and testis) were determined. Compared with those fed a standard diet, HCD induced dyslipidemia and oxidative stress, and decreased numerous reproductive parameters (mobility, count and viability). Interestingly, supplementing the HCD with thornback ray proteins attenuated all these anomalies, especially in the case where they were hydrolysed. These observations suggested that these proteins might contain bioactive peptides that possess hypocholesterolemic and antioxidant activities that ameliorate sperm damage.

Thornback ray muscle hydrolysate was investigated, as well as the undigested muscle, to test their hypolipidemic, antioxidative and fertility effects in rats fed with a high-cholesterol diet.

Regulation mechanism of oxidative stress induced by high glucose through PI3K/Akt/Nrf2 pathway in juvenile blunt snout bream (Megalobrama amblycephala)

This study was conducted to investigate the effects of oral administration of a high concentration of glucose on the respiratory burst, antioxidant status, and hepatic gene expression of heme oxygenase-1 (ho1) and PI3K/Akt/Nrf2-related signaling molecules in juvenile blunt snout bream (Megalobrama amblycephala). Blunt snout bream juveniles with an initial body weight of 19.94 ± 0.58 g were orally fed with a high concentration of glucose (3 g/kg body weight). The results indicated that plasma glucose exhibited a biphasic response. Acute and persistent hyperglycemia due to the oral glucose administration significantly reduced (P < 0.05) the white blood cell count, red blood cell count, and hemoglobin content and caused oxidative stress (significantly increased alanine aminotransferase, aspartate transaminase, alkaline phosphatase, and glucose levels) and early apoptosis of hepatocytes in the fish. Hepatic superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase activities increased rapidly (P < 0.05) as protection from oxidative stress and were downregulated (P < 0.05) because of persistent hyperglycemia. Blood respiratory burst was significantly reduced (P < 0.05) because of hyperglycemia and showed a trend that was opposite to that of plasma glucose. Slight upregulation of nrf2 mRNA and antioxidants acts as a compensative protection mechanism, and the downregulated PI3K/Akt pathway blocked this function of Nrf2. In conclusion, the PI3K/Akt pathway and Nrf2 mediated the antioxidative mechanism independently in the blunt snout bream juveniles subjected to the oral administration of a high glucose concentration.

Effect of pomegranate extracts on brain antioxidant markers and cholinesterase activity in high fat-high fructose diet induced obesity in rat model

Background

To investigate beneficial effects of Pomegranate seeds oil (PSO), leaves (PL), juice (PJ) and (PP) on brain cholinesterase activity, brain oxidative stress and lipid profile in high-fat-high fructose diet (HFD) induced-obese rat.

Methods

In vitro and in vivo cholinesterase activity, brain oxidative status, body and brain weight and plasma lipid profile were measured in control rats, HFD-fed rats and HFD-fed rats treated by PSO, PL, PJ and PP.

Results

In vitro study showed that PSO, PL, PP, PJ inhibited cholinesterase activity in dose dependant manner. PL extract displayed the highest inhibitory activity by IC50 of 151.85 mg/ml. For in vivo study, HFD regime induced a significant increase of cholinesterase activity in brain by 17.4% as compared to normal rats. However, the administration of PSO, PL, PJ and PP to HDF-rats decreased cholinesterase activity in brain respectively by 15.48%, 6.4%, 20% and 18.7% as compared to untreated HFD-rats. Moreover, HFD regime caused significant increase in brain stress, brain and body weight, and lipid profile disorders in blood. Furthermore, PSO, PL, PJ and PP modulated lipid profile in blood and prevented accumulation of lipid in brain and body evidenced by the decrease of their weights as compared to untreated HFD-rats. In addition administration of these extract protected brain from stress oxidant, evidenced by the decrease of malondialdehyde (MDA) and Protein carbonylation (PC) levels and the increase in superoxide dismutase (SOD) and glutathione peroxidase (GPx) levels.

Conclusion

These findings highlight the neuroprotective effects of pomegranate extracts and one of mechanisms is the inhibition of cholinesterase and the stimulation of antioxidant capacity.

Evaluation of Bacillus subtilis SPB1 biosurfactant effects on hyperglycemia, angiotensin I-converting enzyme (ACE) activity and kidney function in rats fed on high-fat-high-fructose diet

This study investigated the protective and the curative effects of Bacillus subtilis SPB1 crude lipopeptide biosurfactant in alleviating induced obesity complications in rats fed on high-fat-high-fructose diet (HFFD). Male Wistar rats were divided into five groups with the following treatment schedule: normal diet-fed rats (CD), HFFD-fed rats, HFFD-fed rats supplemented with SPB1 biosurfactant from the first day of the experiment (HFFD + Bios1), rats fed on HFFD receiving standard drug (HFFD + Torva), or SPB1 biosurfactant (HFFD + Bios2) during the last 4 weeks of the study. HFFD induced hyperglycemia, manifested by a significant (p < 0.001) increase (20%) in the levels of glucose and α-amylase activity in the plasma, when compared with CD. The administration of SPB1 biosurfactant to rats fed on HFFD reverted back normal blood glucose and α-amylase activity levels. Also, the findings clearly showed that acute oral administration of SPB1 biosurfactant reduced significantly (34%) the peak of blood glucose concentration 60 min after glucose administration, as compared with untreated rats fed on HFFD. Furthermore, renal dysfunction indices such as creatinine and urea as well as the level of angiotensin I-converting enzyme (ACE) exhibited remarkable increases in serum of rats fed on HFFD by 28.35%, 46%, and 92%,. Interestingly, SPB1 lipopeptides treatments decreased the creatinine and urea levels significantly (p < 0.001) near normal values, as compared with that of the HFFD group, and also showed an improvement of the kidney cortex architecture. Moreover, SPB1 biosurfactant displayed a potent inhibition of ACE activity in vitro (CI₅₀ value=1.37 mg/mL) as well as in vivo in obese rats by 42% and 27.25% with HFFD + Bios1 and HFFD + Bios2 treatments, respectively, and comparatively with the HFFD group. Besides, SPB1 lipopeptides treatments improved some of serum electrolytes such as Na⁺, K⁺, Ca²⁺, and Mg²⁺. The results showed that SPB1 lipopeptide biosurfactant presented useful hypoglycemic and antihypertensive properties, and was able to alleviate renal lipid deposition in rats fed on a hypercaloric diet.

Marine Peptides as Potential Agents for the Management of Type 2 Diabetes Mellitus-A Prospect

An increasing prevalence of diabetes is known as a main risk for human health in the last future worldwide. There is limited evidence on the potential management of type 2 diabetes mellitus using bioactive peptides from marine organisms, besides from milk and beans. We summarized here recent advances in our understanding of the regulation of glucose metabolism using bioactive peptides from natural proteins, including regulation of insulin-regulated glucose metabolism, such as protection and reparation of pancreatic β-cells, enhancing glucose-stimulated insulin secretion and influencing the sensitivity of insulin and the signaling pathways, and inhibition of bioactive peptides to dipeptidyl peptidase IV, α-amylase and α-glucosidase activities. The present paper tried to understand the underlying mechanism involved and the structure characteristics of bioactive peptides responsible for its antidiabetic activities to prospect the utilization of rich marine organism proteins.

Beneficial effects of fermented sardinelle protein hydrolysates on hypercaloric diet induced hyperglycemia, oxidative stress and deterioration of kidney function in wistar rats

This study investigated the potential effects of fermented sardinelle protein hydrolysates (FSPHs) obtained by two proteolytic bacteria, Bacillus subtilis A26 (FSPH-A26) and Bacillus amyloliquefaciens An6 (FSPH-An6), on hypercaloric diet (HCD) induced hyperglycemia and oxidative stress in rats. Effects of FSPHs on blood glucose level, glucose tolerance, α-amylase activity and hepatic glycogen content were investigated, as well as their effect on the oxidative stress state. Biochemical findings revealed that, while undigested sardinelle proteins did not exhibit hypoglycemic activity, oral administration of FSPHs to HCD-fed rats reduced significantly α-amylase activity as well as glycemia and hepatic glycogen levels. Further, the treatment with FSPHs improved the redox status by decreasing the levels of lipid peroxidation products and increasing the activities of the antioxidant enzymes (superoxide dismutase, glutathione peroxidase and catalase) and the level of glutathione in the liver and kidneys, as compared to those of HCD-fed rats. FSPHs were also found to exert significant protective effects on liver and kidney functions, evidenced by a marked decrease in alkaline phosphatase activity and a modulation of creatinine and uric acid contents. These results indicated the beneficial effect of FSPHs on the prevention from hyperglycemia and oxidative stress.

Protein Hydrolysates and Biopeptides: Production, Biological Activities, and Applications in Foods and Health Benefits. A Review

In recent years, a great deal of interest has been expressed regarding the production, characterization, and applications of protein hydrolysates and food-derived biopeptides due to their numerous beneficial health effects. In this regard, research is mainly focused on investigating the therapeutic potential of these natural compounds. Based on their amino acids composition, sequences, hydrophobicity, and length, peptides released from food proteins, beyond their nutritional properties, can exhibit various biological activities including antihypertensive, antioxidative, antithrombotic, hypoglycemic, hypocholesterolemic, and antibacterial activities among others. Protein hydrolysates are essentially produced by enzymatic hydrolysis of whole protein sources by appropriate proteolytic enzymes under controlled conditions, followed by posthydrolysis processing to isolate desired and potent bioactive peptides from a complex mixture of active and inactive peptides. Therefore, because of their human health potential and safety profiles, protein hydrolysates and biopeptides may be used as ingredients in functional foods and pharmaceuticals to improve human health and prevent diseases. In this review, we have focused on the major variables influencing the enzymatic process of protein hydrolysates production. The biological properties of protein hydrolysates will be described as well as their applications in foods and health benefits.

Mesozeaxanthin Protects Retina from Oxidative Stress in a Rat Model

PURPOSE

Mesozeaxanthin (MZ) is able to protect against chronic and cumulative eye damage and neutralize free radicals produced by oxidative stress. The objective of the present study was to evaluate the protective potential of MZ against retinal oxidative damage and growth and transcription factors of the retina in rats fed with high-fat diet (HFD).

METHODS

Twenty-eight Sprague Dawley rats were randomly divided into the following 4 groups: (1) Control, (2) MZ (100 mg/kg bw/d), (3) HFD (42% of calories as fat), and (4) HFD+MZ (100 mg/kg bw/d) group rats were administered daily as supplement for 12 weeks.

RESULTS

Consumption of HFD was associated with hyperglycemia and oxidative stress as reflected by increased serum MDA concentration (P < 0.001). No measurable zeaxanthin (Z)+MZ and lutein (L) could be detected in the serum of control and HFD rats, whereas they were observed in the serum of MZ-administered rats. Retinal antioxidant enzyme [superoxide dismutase (SOD) and catalase (CAT)] activities were significantly decreased in the HFD group compared to the normal group (P < 0.01). However, retinal antioxidant enzymes were restored close to normal levels in HFD+MZ-treated rats (P < 0.05). The retina of rats fed with HFD had increased levels of vascular endothelial growth factor (VEGF), inducible nitric oxide (iNOS), intercellular adhesion molecule-1 (ICAM-1), and nuclear factor-kappa B (NF-κB) levels and decreased nuclear factor erythroid 2-related factor 2 (Nrf2) and heme-oxygenase 1(HO-1) levels compared to the healthy rat retina (P < 0.001). Rats treated with MZ partially alleviated the inflammation as reflected by suppressed VEGF, iNOS, ICAM, and NF-κB levels and increased Nrf2 and HO-1 levels in the retina of rats fed (P < 0.05).

CONCLUSIONS

Results from the present study suggest that MZ has protective effects on the retina and the ability to modulate oxidative stress of retina in rats fed an HFD by suppressing retinal lipid peroxidation and regulating growth and transcription factors.