Fatty acids characterisation by GC-MS, antiglycation effect at multiple stages and protection of erythrocytes cells from oxidative damage induced by glycation of albumin of Opuntia ficus-indica (L.) Mill seed oil cultivated in Eastern Morocco: Experimental and computational approaches.

ETHNOPHARMACOLOGICAL RELEVANCE: Opuntia ficus-indica (L.) Mill is frequently observed in the Moroccan traditional medicinal system, where these approaches are employed to mitigate the onset of diabetes and the subsequent complications it may entail. AIM OF THE STUDY: The aim of this research was to examine the effectiveness of Opuntia ficus-indica seed oil in preventing diabetic complications. Specifically, the study assessed its ability to counteract glycation at various stages, protected red blood cells from the harmful effects of glycated albumin, and inhibited pancreatic lipase digestive enzymes to understand its potential antihyperglycemic properties. Additionally, the study aimed to identify the chemical components responsible for these effects, evaluate antioxidant and anti-inflammatory properties, and conduct computational investigations such as molecular docking. MATERIALS AND METHODS: The assessement of Opuntia ficus-indica seed oil antiglycation properties involved co-incubating the extract oil with a bovine serum albumin-glucose glycation model. The study investigated various stages of glycation, incorporating fructosamine (inceptive stage), protein carbonyls (intermediate stage), and AGEs (late stage). Additionally, measurement of ß-amyloid aggregation of albumin was performed using Congo red, which is specific to amyloid structures. Additionally, the evaluation of oil's safeguarding effect on erythrocytes against toxicity induced by glycated albumin included the measurement of erythrocyte hemolysis, lipid peroxidation, reduced glutathione. The fatty acid of Opuntia ficus-indica seed oil were analyzed using Gas Chromatography-Mass Spectrometry (GC-MS). The in vitro evaluation of antihyperglycemic activity involved the use of pancreatic lipase enzyme, while the assessement of antioxidant capability was carried out through the utilization of the ABTS and FRAP methods. The in vitro assessement of the denaturation of albumin activity was also conducted. In conjunction with the experimental outcomes, computational investigations were undertaken, specifically employing ADMET (absorption, distribution, metabolism, excretion, and toxicity) analysis. Furthermore, molecular docking was utilized to predict antioxidant and antiglycation mechanisms based on protein targets. RESULTS: In vitro glycation assays, Opuntia ficus-indica seed oil displayed targeted inhibitory effects at multiple distinct stages. Within erythrocytes, in addition to mitigating hemolysis and lipid peroxidation induced by glycated albumin. GC-MS investigation revealed a richness of fatty acids and the most abundant compounds are Linoleic acid (36.59%), Palmitic acid (20.84%) and Oleic acid (19.33%) respectively. The findings of antioxidant ability showed a remarkable activity on FRAP and ABTS radicals. This oil showed a pronounced inhibitory impact (p < 0.001) on pancreatic lipase enzyme. It also exerted a notibale inhibition of albumin denaturation, in vitro. CONCLUSION: The identified results were supported by the abundant compounds of fatty acids unveiled through GC-MS analysis, along with the computational investigation and molecular docking.

Genipin ameliorates diabetic retinopathy via the HIF-1α and AGEs-RAGE pathways.

BACKGROUND: Traditional Chinese medicine (TCM) is useful in disease treatment and prevention. Genipin is an active TCM compound used to treat diabetic retinopathy (DR). In this study, a network pharmacology (NP)-based approach was employed to investigate the therapeutic mechanisms underlying genipin administration in DR. METHODS: The potential targets of DR were identified using the gene expression omnibus (GEO) database. TCM database screening and NP were used to predict the potential active targets and pathways of genipin in DR. Cell viability was tested in vitro to determine the effects of different doses of glucose and genipin on Human Retinal Microvascular Endothelial Cells (hRMECs). CCK-8, CCK-F, colony formation, CellTiter-Lum, Annexin V-FITC, wound healing, Transwell, tube-forming, reactive oxygen species (ROS), and other assay kits were used to detect the effects of genipin on hRMECs during high levels of glucose. In vivo, a streptozotocin (STZ)-mouse intraocular genipin injection (IOI.) model was used to explore the effects of genipin on diabetes-induced retinal dysfunction. Western blotting was performed to identify the cytokines involved in proliferation, apoptosis, angiogenesis, ROS, and inflammation. The protein expression of the AKT/ PI3K/ HIF-1α and AGEs/ RAGE pathways was also examined. RESULTS: Approximately 14 types of TCM, and nearly 300 active ingredients, including genipin, were identified. The NP approach successfully identified the HIF-1α and AGEs-RAGE pathways, with the EGR1 and UCP2 genes, as key targets of genipin in DR. In the in vitro and in vivo models, we discovered that high glucose increased cell proliferation, apoptosis, angiogenesis, ROS, and inflammation. However, genipin application regulated cell proliferation and apoptosis, inhibited angiogenesis, and reduced ROS and inflammation in the HRMECs exposed to high glucose. Furthermore, the retinal thickness in the genipin-treated group was lower than that in the untreated group. AKT/ PI3K/ HIF-1α and AGEs/ RAGE signaling was increased by high glucose levels; however, genipin treatment decreased AKT/ PI3K and AGEs/ RAGE pathway expressions. Genipin also increased HIF-1α phosphorylation, oxidative phosphorylation of ATP synthesis, lipid peroxidation, and the upregulation of oxidoreductase. Genipin was found to protect HG-induced hRMECs and the retina of STZ-mice, based on; 1 the inhibition of UCP2 and Glut1 decreased intracellular glucose, and glycosylation; 2 the increased presence of HIF-1α, which increased oxidative phosphorylation and decreased substrate phosphorylation; 3 the increase in oxidative phosphorylation from ATP synthesis increased lipid peroxidation and oxidoreductase activity, and; 4 the parallel effect of phosphorylation and glycosylation on vascular endothelial growth factor (VEGF), MMP9, and Scg3. CONCLUSION: Based on NP, we demonstrated the potential targets and pathways of genipin in the treatment of DR and confirmed its effective molecular mechanism in vitro and in vivo. Genipin protects cells and tissues from high glucose levels by regulating phosphorylation and glycosylation. The activation of the HIF-1α pathway can also be used to treat DR. Our study provides new insights into the key genes and pathways associated with the prognosis and pathogenesis of DR.

Galactooligosaccharides in infant formulas: Maillard reaction characteristics and influence on formation of advanced glycation end products.

As prebiotics supplemented in infant formulas (IFs), galactooligosaccharides (GOSs) also have many other biological activities; however, their Maillard reaction characteristics are still unclear. We investigated the Maillard reactivity of GOSs and their effects on advanced glycation end product (AGE) formation during IF processing. The results showed that AGE and HMF formation was temperature-dependent and reached the maximum at pH 9.0 in the Maillard reaction system of GOSs and Nα-acetyl-L-lysine. Acidic conditions accelerated HMF formation; however, protein cross-linking was more likely to occur under alkaline conditions. The degree of polymerization (DP) of GOSs had no significant effect on AGEs formation (except pyrraline); however, the greater the DP, the higher the concentration of HMF and pyrraline. Besides, compared with arginine and casein, lysine and whey protein were more prone to Maillard reaction with GOSs. GOSs promoted AGEs formation in a dose-dependent manner during the processing of IFs. These results provide a reliable theoretical basis for application of GOSs in IFs.

Mechanistic role of Syzygium cumini (L.) Skeels in glycation induced diabetic nephropathy via RAGE-NF-κB pathway and extracellular proteins modifications: A molecular approach.

ETHNOPHARMACOLOGY RELEVANCE: Syzygium cumini (L.) Skeels (SC), an ancient medicinal plant, is used as a complementary and alternative medicine for treating diabetes mellitus and its associated complications, such as diabetic nephropathy (DN). Phytochemicals present in SC homeopathic formulations possess anti-glycemic, anti-glycation, anti-inflammatory, and antioxidant properties. Additionally, the non-enzymatic formation of advanced glycation end products (AGEs) increases during hyperglycemia in diabetes. AGEs interaction with their receptor of AGEs (RAGE) promotes inflammation via Nuclear Factor-κB (NF-κB) and the accumulation of Extracellular Matrix (ECM) proteins, contributing to the renal dysfunction in DN. However, the molecular mechanism through which SC formulations interact with the AGEs-RAGE-NF-κB pathway has not yet been investigated. AIM: This study aims to examine the impact of SC formulations on the RAGE-NF-κB pathway and ECM protein modifications in glycation-induced DN using a molecular approach. MATERIALS AND METHODS: Human serum albumin (10 mg/ml) was glycated with MGO (55 mM) in the presence of SC formulations - Mother tincture (MT), 30C, 200C for 7 days. Glycated samples were added to renal cells (HEK 293) for 24 h. Subsequently, cellular gene and protein expressions of RAGE, NF-κB, vascular endothelial growth factor (VEGF), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), collagen IV (Col IV), and fibronectin were determined using RT-qPCR and Western blot analysis. The immunofluorescence, luciferase assay, and chromatin immunoprecipitation techniques were employed to gain insights into glycation-induced NF-κB nuclear translocation, transcriptional activity, and its effect on RAGE promoter activity in SC-treated cells. RESULTS: SC formulations significantly downregulated glycation-induced elevated levels of RAGE and NF-κB. Mechanistically, SC formulations prevented NF-κB nuclear translocation, transcriptional activity, and RAGE promoter activity. Also, SC formulations significantly attenuated glycation-enhanced expressions of inflammatory cytokines (IL-6, TNF-α, and VEGF) and ECM proteins (Col IV and fibronectin). CONCLUSION: Our findings enlighten the molecular mechanism of SC in DN by targeting the AGEs-RAGE-NF-κB signaling pathway, inflammatory responses, and ECM accumulation. Hence, the study validates the protective role of SC formulations and signifies its novel potential for treating DN.

Structure relationship of non-covalent interactions between lotus seedpod oligomeric procyanidins and glycated casein hydrolysate during digestion.

Procyanidin-amino acid interactions during transmembrane transport cause changes in the structural and physical properties of peptides, which limits further absorption of oligopeptide-advanced glycation end products (AGEs). In this study, glycated casein hydrolysates (GCSHs) were employed to investigate the structure and interaction mechanism of GCSH with lotus seedpod oligomeric procyanidin (LSOPC) complexes in an intestinal environment. LSOPC can interact with GCSH under certain conditions to form hydrogen bonds and hydrophobic interactions to form GCSH-LSOPC complexes. Results showed that procyanidin further leads to the transformation of a GCSH secondary structure and the increase of surface hydrophobicity (H0). The strongest non-covalent interaction between GCSH and (-)-epigallocatechin gallate (EGCG) was due to the polyhydroxy structure of EGCG. Binding site analysis showed that EGCG binds to the internal cavity of P1 to maintain the relative stability of the binding conformation. The antioxidant capacity of GCSH was remarkably elevated by GCSH-LSOPC. This study will provide a new reference for the accurate control of oligopeptide-AGEs absorption by LSOPC in vivo.

Integrating network pharmacology and experimental validation to decipher the mechanism of the Chinese herbal prescription modified Shen-Yan-Fang-Shuai formula in treating diabetic nephropathy.

CONTEXT: Diabetic nephropathy (DN) is the main cause of end-stage renal disease. Modified Shen-Yan-Fang-Shuai formula (M-SYFSF) has excellent clinical efficacy in treating diabetic kidney disease. However, the potential mechanism of M-SYFSF remains unknown. OBJECTIVE: To investigate the mechanism of M-SYFSF against DN by network pharmacological analysis and biological experiments. MATERIALS AND METHODS: Utilizing a web-based pharmacology database, the potential mechanisms of M-SYFSF against DN were identified. In vivo experiments, male SD rats were injected with streptozotocin (50 mg/kg) and got uninephrectomy to construct a model of DN. M-SYFSF (11.34 g/kg/d) was gavaged once per day for 12 weeks after model establishment. In vitro experiments, human proximal tubular cells (HK-2) were performed with advanced glycation end-products (AGEs) (100 µg/mL), then intervened with M-SYFSF freeze-dried powder. Pathological staining, WB, IHC, ELISA were conducted to explore the mechanism of M-SYFSF against DN. RESULTS: Network pharmacological analysis showed that MAPK pathway was the potential pathway. Results showed that compared with the Model group, M-SYFSF significantly reduced 24h urine albumin, UACR, and serum creatinine levels (54.90 ± 26.67 vs. 111.78 ± 4.28, 8.87 ± 1.69 vs. 53.94 ± 16.01, 11.56 ± 1.70 vs. 118.70 ± 49.57, respectively), and improved renal pathological changes. Furthermore, the intervention of M-SYFSF reduced the expression of pro-inflammatory cytokines and inhibited the activation of MAPK pathway in AGEs-treated HK-2 cells. DISCUSSION AND CONCLUSION: M-SYFSF is likely to reduce inflammation in DN by inhibiting the MAPK pathway. It provides a theoretical basis for the clinical application of M-SYFSF in the treatment of DN.

Network pharmacology-based study on the mechanism of ShenKang injection in diabetic kidney disease through Keap1/Nrf2/Ho-1 signaling pathway.

OBJECTIVE: To study the effect of ShenKang Injection (SKI) on the kidneys of DKD rats and its effect on oxidative stress mediated by the Keap1/Nrf2/Ho-1 signaling pathway through network pharmacology and in vivo and in vitro experiments. METHODS: SKI drug targets were screened by TCMSP, DKD targets were screened by GenGards, OMIM, Drugbank, TTD, and Disgenet databases, and the two intersected for PPI network analysis and target prediction was performed by GO and KEGG. A total of 40 SD rats were randomly divided into 10 in the control group and 30 in the model group. After the model group was fed 8 W with high-sugar and high-fat diets, a DKD model was constructed by one-time intraperitoneal injection of streptozotocin (35 mg/kg). According to the weight, the model animals were randomly divided into three groups: 8 for model validation group, 8 for Irbesartan (25 mg/kg daily) group, and 8 for SKI group (5 ml/kg). Gavaged deionized water was given to the control group and the model validation group equally. The general conditions of the rats were observed, their body weights measured and their urine volumes recorded for 24 h. After the intervention of 16 W, serum was collected to detect Urea, Scr, blood lipids, and oxidative stress and lipid peroxidation indicators; Transmission electron microscopy, HE and Mallory staining were used to observe the pathological morphology of renal tissue. Immunohistochemistry and RT-PCR were used to detect the expression of Keap1, Nrf2, Ho-1, Gpx4 proteins and mRNA in rat kidney tissues. HK-2 cells were cultured in vitro and divided into: the control group, AGEs (200 µg/ml) group and AGEs + SKI group. The cell activity of the groups was detected using CCK-8 after 48 h of cell culture, and ROS were detected using fluorescent probes. Gpx4 expression was detected by immunofluorescence, while Keap1, Nrf2, Ho-1, and Gpx4 were detected by Western Blot. RESULTS: Network pharmacological analysis predicted that SKI may delay DKD kidney injury by affecting redox-related signaling pathways and mitigating AGEs-induced oxidative stress. In the animal experiment, compared with the model validation group, the general state of rats in the SKI group was improved, and 24-hour urine protein levels were significantly reduced, and the Scr in the serum was reduced. A decreasing trend was seen in Urea, and TC, TG, and LDL levels significantly decreased and the levels of ROS, LPO and MDA were significantly lowered. Pathological staining showed that renal interstitial fibrosis was significantly improved, and electron microscopy showed that foot process effacement was alleviated. Immunohistochemistry and RT-PCR showed decreased expression of Keap1 protein and mRNA in kidney tissues of the SKI group. Additionally, Nrf2, Ho-1, and Gpx4 proteins and mRNA were expressed significantly. In the cell experiment, after 48 h treatment with AGEs, ROS in HK-2 cells increased significantly and cell activity decreased significantly, while cell activity in AGEs + SKI group increased significantly and ROS decreased. The expression of Keap1 protein in HK-2 cells in the AGEs + SKI group decreased, while the expression of Nrf2, Ho-1 and Gpx4 proteins increased significantly. CONCLUSION: SKI can protect kidney function in DKD rats, delay DKD progression, inhibit AGEs-induced oxidative stress damage in HK-2 cells, and the mechanism of SKI to improve DKD may be achieved by activating the Keap1/Nrf2/Ho-1 signal transduction pathway.

AFG, an important maillard reaction product in red ginseng, alleviates D-galactose-induced brain aging in mice via correcting mitochondrial dysfunction induced by ROS accumulation.

Red ginseng is a classical processed product from Panax ginseng. C.A Meyer with many bioactive components formed through the Maillard reaction called Maillard reaction products. Maillard reaction refers to complex reversible reactions between amino acids or proteins and glycosides, which are used in food processing and storage, as well as in tobacco development, traditional Chinese medicine processing, and wine brewing. Arginyl-fructosyl-glucose (AFG) is a main non-saponin (ginsenoside) component produced in red ginseng processing, with high antioxidant, anti-apoptotic and neuroprotective efficiencies. However, its effects and mechanisms against oxidation stress in on the brain remain elusive. Therefore, this study aimed at exploring the therapeutic effect exerted by AFG on murine subacute brain aging induced by D-galactose (D-gal) and its potential molecular mechanism in the murine model, finding that AFG (40 and 80 mg/kg) significantly ameliorated D-gal-resulted changes in pathology. Besides, according to the transmission electron microscopy (TEM) and Western blot, AFG corrected the mitochondrial dysfunction resulted from ROS, thereby delaying the mice brain aging caused by D-gal.

Hesperetin treatment attenuates glycation of lens proteins and advanced­glycation end products generation.

Advanced glycation end products (AGEs) in lens proteins increase with aging, thus inducing cataracts and/or presbyopia. Hesperetin (Hst), which is an abundant plant flavanone largely derived from citrus species, and its derivatives attenuate cataracts and presbyopia in vivo and in vitro; however, no reports have described its effects on AGE formation in lens proteins. The present study demonstrated that AGEs in lens proteins increase with age in mice. Additionally, it showed that Hst can prevent AGEs and N(ε)­carboxymethyl­lysine generation and modification of lens proteins using in vitro in human lens epithelial cell lines and ex vivo in mouse lens organ cultures. Furthermore, treatment with Hst prevented lens hardening and decreased chaperone activity in lens proteins. These results suggested that Hst and its derivatives are good candidates for the prevention of presbyopia and cataracts.

Antidiabetic and anti-obesity properties of a polyphenol-rich flower extract from Tagetes erecta L. and its effects on Caenorhabditis elegans fat storages.

Diabetes mellitus (DM) is a metabolic disease characterized by a high blood sugar level that can cause severe complications to the organism or even death when not treated. However, certain dietary habits and foods may have beneficial effects on this condition. A polyphenolic-rich extract (containing hyperoside, isoquercitrin, quercetin, ellagic acid, and vanillic acid) of Tageres erecta L. (T. erecta) was obtained from yellow and orange flowers using an ethanolic Soxhlet extraction. These extracts were screened for antidiabetic and anti-obesity properties using in vitro and in vivo procedures. The capacity to inhibit the enzymes lipase and α-glucosidase, as well as the inhibition of advance glycation end-products (AGEs) was tested in vitro. Caenorhabditis elegans (C. elegans) was used as an obesity in vivo model to assess extracts effects on fat accumulation using the wild-type strain N2 and a mutant with no N3 fatty acid desaturase activity BX24. Extracts from both cultivars (yellow and orange) T. erecta presented in vitro inhibitory activity against the enzymes lipase and α-glucosidase, showing lower IC50 values than acarbose (control). They also showed important activity in preventing AGEs formation. The polyphenol-rich matrices reduced the fat content of obese worms in the wild-type strain (N2) down to levels of untreated C. elegans, with no significant differences found between negative control (100% reduction) and both tested samples (p < 0.05). Meanwhile, the fat reduction was considerably lower in the BX24 mutants (fat-1(wa-9)), suggesting that N3 fatty acid desaturase activity could be partially involved in the T. erecta flower effect. Our findings suggested that polyphenols from T. erecta can be considered candidate bioactive compounds in the prevention and improvement of metabolic chronic diseases such as obesity and diabetes.

Methylglyoxal products in pre-symptomatic type 1 diabetes.

Introduction: Progression to type 1 diabetes has emerged as a complex process with metabolic alterations proposed to be a significant driver of disease. Monitoring products of altered metabolism is a promising tool for determining the risk of type 1 diabetes progression and to supplement existing predictive biomarkers. Methylglyoxal (MG) is a reactive product produced from protein, lipid, and sugar metabolism, providing a more comprehensive measure of metabolic changes compared to hyperglycemia alone. MG forms covalent adducts on nucleic and amino acids, termed MG-advanced glycation end products (AGEs) that associate with type 1 diabetes. Methods: We tested their ability to predict risk of disease and discriminate which individuals with autoimmunity will progress to type 1 diabetes. We measured serum MG-AGEs from 141 individuals without type 1 diabetes and 271 individuals with type 1 diabetes enrolled in the Fr1da cohort. Individuals with type 1 diabetes were at stages 1, 2, and 3. Results: We examined the association of MG-AGEs with type 1 diabetes. MG-AGEs did not correlate with HbA1c or differ between stages 1, 2, and 3 type 1 diabetes. Yet, RNA MG-AGEs were significantly associated with the rate of progression to stage 3 type 1 diabetes, with lower serum levels increasing risk of progression. Discussion: MG-AGEs were able to discriminate which individuals with autoantibodies would progress at a faster rate to stage 3 type 1 diabetes providing a potential new clinical biomarker for determining rate of disease progression and pointing to contributing metabolic pathways.

Cornuside, by regulating the AGEs-RAGE-IκBα-ERK1/2 signaling pathway, ameliorates cognitive impairment associated with brain aging.

Anti-Alzheimer's disease (AD) drugs can only change the symptoms of cognitive impairment in a short time but cannot prevent or completely cure AD. Thus, a more effective drug is urgently needed. Cornuside is extracted from Corni Fructus, a traditional Chinese medicine that plays an important role in treating dementia and other age-related diseases. Thus, the study aimed to explore the effects and mechanisms of Cornuside on the D-galactose (D-Gal) induced aging mice accompanied by cognitive decline. Initially, we found that Cornuside improved the learning and memory abilities of D-Gal-treated mice in behavioral experiments. Pharmacological experiments indicated that Cornuside acted on anti-oxidant and anti-inflammatory effects. Cornuside also reversed acetylcholin esterase (AChE) activity. Meanwhile, pathology tests showed that Cornuside had a protective effect on neuron damage. Cornuside increased the expression of brain-derived neurotrophic factor (BDNF), and down-regulated the expression of receptor for advanced glycosylation end products (RAGE), ionized calcium binding adapter molecule 1 (Iba1), and glial fibrillary acidic protein (GFAP) respectively. Further studies claimed that Cornuside had important effects on the expression of IκBα and extracellular signal-regulated kinases 1/2 (ERK1/2). These effects might be achieved through regulating the AGEs-RAGE-IκBα-ERK1/2 signaling pathway, among which, ERK1/2 might be the key protein. The study provides direct preclinical evidence for the research of Cornuside, which may become an excellent candidate drug for the treatment of aging-related AD.

Asiatic acid attenuates tubular injury in diabetic kidney disease by regulating mitochondrial dynamics via the Nrf-2 pathway.

BACKGROUND: Mitochondrial dynamics plays a crucial role in tubular injury in diabetic kidney disease (DKD). Asiatic acid (AA) has demonstrated renal protective effects in DKD; however, its therapeutic effect on tubular injury in DKD remains unclear. PURPOSE: This study aimed to verify the effects of AA on tubular injury in DKD and underlying mechanisms. STUDY DESIGN: In the present study, the effects of AA on tubular injury were assessed in rats with streptozotocin-induced diabetes and advanced glycation end products (AGEs)-stimulated HK-2 cells models. METHODS: After oral administration with or without AA for ten weeks, body weight and levels of fast blood glucose, serum creatinine (sCr), blood urea nitrogen (BUN), urinary albumin, and kidney injury molecule-1 (KIM-1) were detected. Histological analysis was performed to evaluate the renal function of rats. Moreover, the expression of proteins associated with the Nrf-2 pathway and mitochondrial dynamics was analyzed. AGEs-stimulated HK-2 cells were examined to evaluate the tubular protection and the mechanism of AA in vitro. RESULTS: AA remarkably decreased albumin levels, KIM-1 levels in urine, and serum Cr, and BUN levels. In addition, AA prevented tubular injury and mitochondrial injury by regulating the Nrf-2 pathway and mitochondrial dynamics. Furthermore, the effects of AA on mitochondrial dynamics and tubular protection were eliminated after treatment with ML385 (Nrf2 inhibitor). CONCLUSION: These findings suggested that AA might be developed as a potential candidate for the treatment of tubular injury in DKD, and its effects are potentially mediated via the regulation of the Nrf-2 pathway and mitochondrial dynamics.

Dietary polyphenols: regulate the advanced glycation end products-RAGE axis and the microbiota-gut-brain axis to prevent neurodegenerative diseases.

Advanced glycation end products (AGEs) are formed in non-enzymatic reaction, oxidation, rearrangement and cross-linking between the active carbonyl groups of reducing sugars and the free amines of amino acids. The Maillard reaction is related to sensory characteristics in thermal processed food, while AGEs are formed in food matrix in this process. AGEs are a key link between carbonyl stress and neurodegenerative disease. AGEs can interact with receptors for AGEs (RAGE), causing oxidative stress, inflammation response and signal pathways activation related to neurodegenerative diseases. Neurodegenerative diseases are closely related to gut microbiota imbalance and intestinal inflammation. Polyphenols with multiple hydroxyl groups showed a powerful ability to scavenge ROS and capture α-dicarbonyl species, which led to the formation of mono- and di- adducts, thereby inhibiting AGEs formation. Neurodegenerative diseases can be effectively prevented by inhibiting AGEs production, and interaction with RAGEs, or regulating the microbiota-gut-brain axis. These strategies include polyphenols multifunctional effects on AGEs inhibition, RAGE-ligand interactions blocking, and regulating the abundance and diversity of gut microbiota, and intestinal inflammation alleviation to delay or prevent neurodegenerative diseases progress. It is a wise and promising strategy to supplement dietary polyphenols for preventing neurodegenerative diseases via AGEs-RAGE axis and microbiota-gut-brain axis regulation.

Effect of the simulated digestion process on the chlorogenic acid trapping activity against methylglyoxal.

Chlorogenic acids are hydroxycinnamic derivatives widespread in food or food by-products, known for their antioxidant effects and ability to interfere with the formation of advanced glycation end products (AGEs). AGEs are potential glycotoxins involved in age-related disorders, such as diabetes, cardiovascular diseases, and neurological disorders. The ability of chlorogenic acids to inhibit AGE formation under physiological conditions needs further investigation other than the in vitro assays. Therefore, in this study, the capacity of 5-caffeoylquinic acid (5-CQA) to effectively trap methylglyoxal (MGO), an AGE precursor compound also present in daily consumed food, was investigated by evaluating 5-CQA and MGO metabolic fate when subjected to digestion. Two different in vitro digestion approaches (static based on the Infogest protocol and dynamic based on a novel millifluidic gastrointestinal model) were set up and the samples collected at different steps of the static and dynamic processes were analyzed by a validated RP-HPLC-DAD method. The obtained results indicated that the gastrointestinal process strongly affected the 5-CQA capacity to trap MGO and its resulting antiglycation activity. Therefore, preliminary investigation using advanced in vitro tests, particularly dynamic approaches, should always be performed to predict the effect of the digestion process on the potential bioactives present in food, food by-products, or plant extracts.

Moringa oleifera impedes protein glycation and exerts reno-protective effects in streptozotocin-induced diabetic rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Moringa oleifera is a valued plant with wide distribution in tropical and subtropical regions of the world. It is traditionally used for the treatment of fever, infections, rheumatism, cancer, improving cardiac, renal and hepatic functions, and regulating blood glucose level. The plant has been scientifically reported for the anti-inflammatory, antioxidant, renoprotective, and anti-diabetic properties. Diabetic patients are prone to develop end-stage renal diseases due to incidence of diabetes-induced renal dysfunctions. Given that, increased production and accumulation of advanced glycation end-products (AGEs) play a conspicuous role in the development of diabetes-linked renal dysfunctions, nature-based interventions with AGEs inhibitory activity can prevent renal dysfunctions leading to renoprotection. AIM OF THE STUDY: The study aimed to demonstrate the preventive effects of the ethanolic extract of the leaves of Moringa oleifera (EEMO) on protein glycation and its further assessment for the renoprotective effect in diabetic rats. MATERIALS AND METHODS: Antiglycation activity of EEMO was assessed in vitro using bovine serum albumin. For reno-protective activity assessment, streptozotocin (STZ)-induced diabetic rats were orally treated with EEMO (100 mg/kg) or standard antiglycation agent aminoguanidine (100 mg/kg) for consecutive 8 weeks. The effects on glucose homeostasis, renal functions, and renal morphology were assessed by clinical biochemistry, molecular and histological examination. RESULTS: Presence of EEMO efficiently prevented glucose-, fructose- or methylglyoxal-mediated glycation of protein. Under in vivo set-up, compared to diabetic control rats, EEMO treatment effectively improved the glucose tolerance and body weight, and reduced the serum levels of triglycerides and total cholesterol. Additionally, EEMO administration significantly ameliorated renal dysfunctions in diabetic rats characterized by improved levels of creatinine, urea nitrogen, and uric acid in serum, and total protein level in urine, accompanied by improved kidney morphology. The diabetes-associated pro-inflammatory response characterized by upregulated expression of the inducible nitric oxide synthase (iNos), activation of nuclear factor kappa B (NF-κB) and the raised levels of inflammatory factors, interleukin-1 beta (IL-1ß) and interleukin-6 (IL-6) in renal tissue was significantly attenuated in EEMO-treated rats. Moreover, EEMO treatment diminished renal reactive oxygen species (ROS) levels in diabetic animals. CONCLUSIONS: Our study demonstrated that EEMO prevented AGEs formation and ameliorated renal dysfunctions in diabetic rats by blocking inflammatory/oxidative pathways. Our observations justify M. oleifera as a potential source of therapeutic interventions for diabetic nephropathy management.

Plantamajoside attenuates cardiac fibrosis via inhibiting AGEs activated-RAGE/autophagy/EndMT pathway.

Advanced glycation end products (AGEs) have been identified to transduce fibrogenic signals via inducing the activation of their receptor (RAGE)-mediated pathway. Recently, disrupting AGE-RAGE interaction has become a promising therapeutic strategy for chronic heart failure (CHF). Endothelial-to-mesenchymal transition (EndMT) is close to the cardiac fibrosis pathological process. Our previous studies have demonstrated that knockout RAGE suppressed the autophagy-mediated EndMT, and thus alleviated cardiac fibrosis. Plantamajoside (PMS) is the major bioactive compound of Plantago Asiatica, and its activity of anti-fibrosis has been documented in many reports. However, its effect on CHF and the underlying mechanism remains elusive. Thus, we tried to elucidate the protective role of PMS in CHF from the viewpoint of the AGEs/RAGE/autophagy/EndMT axis. Herein, PMS was found to attenuate cardiac fibrosis and dysfunction, suppress EndMT, reduce autophagy levels and serum levels of AGEs, yet did not affect the expression of RAGE in CHF mice. Mechanically, PMS possibly binds to the V-domain of RAGE, which is similar to the interaction between AGEs and RAGE. Importantly, this competitive binding disturbed AGEs-induced the RAGE-autophagy-EndMT pathway in vitro. Collectively, our results indicated that PMS might exert an anti-cardiac fibrosis effect by specifically binding RAGE to suppress the AGEs-activated RAGE/autophagy/EndMT pathway.

Synergistic properties of garlic and Citrullus colocynthis on reproductive injury caused by diabetes in male rats: Structural and molecular evidence.

This study evaluates the synergistic effect of garlic and Citrullus colocynthis on diabetic reproductive damage by suppressing the AGEs/RAGE/Nox-4 signaling pathway. Thirty-five male Wistar rats were divided into five groups (n = 7/group): Control, Diabetic, Diabetic+G (Garlic, 1 mL/100 g b.w), Diabetic+C (C. colocynthis, 10 mg/kg b.w) and Diabetic+GC (Garlic, 1 mL/100 g b.w and C. colocynthis, 10 mg/kg b.w) groups. At the end of the experimental period (30 days), in diabetic rats, glucose increased, and body & testis weight, luteinizing hormone (LH) and testosterone levels, and sperm count decreased significantly and histopathological injuries were observed. In addition, they have increased testicular apoptosis and oxidative stress. Also, the mechanism based on advanced glycation end products (AGEs)/receptors for advanced glycation end products (RAGE)/NADPH oxidase-4 (Nox-4) was activated in diabetic rats. Separate consumption of garlic and C. colocynthis in Diabetic+G and Diabetic+C groups alleviated the negative adverse effect of diabetes to some extent, but when they were used in the combination form (Diabetic+GC) improvement was profound. Testis histopathology, increased body and testis weight, and enhanced capacity in protecting diabetic reproductive injury was seen. Decreases in testosterone and LH concentration and sperm count in diabetic rats were also reversed by combined administration of garlic and C. colocynthis. It regulated oxidative stress markers, meanwhile reducing caspase-3 immunoexpression. In addition, overexpression of RAGE, Nox-4 and nuclear transcription factor-κB (NF-κB) was inhibited by the combination of garlic and C. colocynthis. PRACTICAL APPLICATIONS: Diabetes mellitus is wide spread all around the world with variety of complications in body including reproductive system in which patients suffer from physical and psychological aspects. Despite many efforts in providing agents for controlling diabetes and its complications, economic conditions of some countries make it difficult for people to provide costly medicine and as a result, they have to bear the complications until they pass away. However, traditional medicine is still finding its way, especially in poor countries with emphasis on medicinal plants. There have been many studies on plants to alleviate diabetes or its side effects. But, using one plant for long term, may be not so effective. Here, we attempted to find whether two plants from two different species can show more efficacy than each one alone. We noticed garlic and Citrullus colocynthis despite having beneficial effects when used alone, they could show synergistic effects in combination.

Independent and combined effects of liraglutide and aerobic interval training on glycemic control and cardiac protection in diabetic cardiomyopathy rats.

OBJECTIVE: This study intended to explore the hypoglycemic and cardioprotective effects of 8-week aerobic interval training combined with liraglutide and elucidate the underlying mechanisms. METHOD: Male Wistar rats were randomly divided into 5 groups - normal control group (CON), diabetic cardiomyopathy group (DCM), high-dose liraglutide group (DH), low-dose liraglutide group (DL), and aerobic interval training combined with liraglutide group (DLE). High-fat diet and streptozotocin (STZ) were used to induce the DCM model, and both the liraglutide administration group and combination therapy group allocated to 8 weeks of either liraglutide or liraglutide and exercise intervention. Cardiac functions were analyzed by electrocardiography. Blood biochemical parameters were measured to judge glycemic control conditions. Hematoxylin and eosin (HE) staining and Sirus red staining was used to identify cardiac morphology and collagen accumulation, respectively. Advanced glycation end products (AGEs) were determined by enzymatic methods. The mRNA expression of myocardial remodeling genes (BNP, GSK3ß, α-MHC, ß-MHC and PPARα) and the protein expression of GLP-1, GLP-1R were analyzed. RESULTS: DCM rats developed hyperglycemia, impaired cardiac function with accumulation of AGEs and collagen (P < 0.05). The development of hyperglycemia and cardiac dysfunction was significantly attenuated with all interventions, as reduced cardiac fibrosis and improved cardiac function (P < 0.05). Cardiac remodeling genes were normalized after all interventions, these positive modifications were due to increased GLP-1 and GLP-1R expression in DCM heart (P < 0.05). Liraglutide combined with AIT significantly increased the diameters of cardiomyocytes, increased the α-MHC expressionx, reduced PPARαexpression and reduced the fluctuation of blood glucose level, which showed the safety and effective of medicine combined with exercise. CONCLUSION: Liraglutide combined with AIT intervention normalized blood glucose alleviates myocardial fibrosis and improves cardiac contractile function in DCM rats, supporting the efficacy and safety of the combination therapy.

Antiglycation potential of plant based TiO2 nanoparticle in D-ribose glycated BSA in vitro.

Biosynthetic procedure is one of the best alternatives, inexpensive and ecologically sound for the synthesis of titanium dioxide (TiO2 ) nanoparticles using a methanolic extract of medicinal plant. The main prospect of this study was to investigate the antiglycation activity of the TiO2 nanoparticles (TNP) prepared by ethanolic leaf extract of the Coleus scutellarioides. In this study, biosynthesized TNP characterized with UV-Visible spectroscopy, X-ray diffraction, Fourier transform infrared spectroscopy and scanning electron microscope. These TNP were further investigated with respect to their antiglycation property and it was checked in the mixture of d-ribose glycated bovine serum albumin (BSA) by measuring ketoamine, carbonyl content, Advanced glycation end products (AGEs) and aggregation of protein instigated by glycation process. The inhibitory effect of TNP to restore the structure of BSA in presence of d-ribose were also characterize by biophysical techniques mentioned above. Therefore, the findings of this study suggest repurposing of TNP for its antiglycation property that could be helpful in prevention of glycation instigated AGEs formation and structural loss of proteins.