L-lysine supplementation improved glycemic control, decreased protein glycation, and insulin resistance in type 2 diabetic patients

Serum biochemical evaluation following administration of imidazolyl thiazolidinedione in streptozotocin-induced diabetic rats

BACKGROUND

Diabetes mellitus represents a prominent global health concern, characterized by a rising prevalence rate. Type 2 Diabetes Mellitus (T2DM) is purported to be associated with an intricate interplay of genetic, environmental, and lifestyle factors. While some progress have been made in T2DM management, controlling associated complications remains a great challenge in medicine.

OBJECTIVES

This study investigated a synthesized Imidazolyl Thiazolidinedione antidiabetic agent (PA9), focusing on serum parameters.

METHODS

Streptozotocin-induced diabetic rats (n = 6) were subjected to orally treatment with PA9 (synthesized by Shakour et al. in an equal dose of a standard drug, 0.011 mmol/kg). The study conducted to measure some specific serum factors, including lipid profiles, liver and kidney enzymes, cardiac enzymes, and oxidative stress markers, both before and after treatment.

RESULTS

The study findings indicated that PA9 effectively ameliorates hyperlipidemia by significantly reducing total cholesterol and triglyceride levels in serum. Additionally, PA9 demonstrated hepatoprotective effects against TZD-induced injuries, as evidenced by decreased levels of alanine transaminase and, alkaline phosphatase. In addition, PA9 also exhibited a modulatory effect on a cardiac injury marker, creatine kinase MB. Moreover, PA9 demonstrated antioxidant properties by reducing oxidative stress markers and enhancing the activities of catalase, thiol, and superoxide dismutase.

CONCLUSIONS

The synthesized TZD compound (PA9) stands out as a highly promising agent for the management of diabetes. Its significant antihyperlipidemic effects, preventive influences on organ injuries, and demonstrated efficacy in reducing oxidative stress marker (SOD) make it therapeutic agent in diabetes management. This study lays the groundwork for innovative strategies in diabetes management.

The Vicious Cycle of Type 2 Diabetes Mellitus and Skeletal Muscle Atrophy: Clinical, Biochemical, and Nutritional Bases

Today, type 2 diabetes mellitus (T2DM) and skeletal muscle atrophy (SMA) have become increasingly common occurrences. Whether the onset of T2DM increases the risk of SMA or vice versa has long been under investigation. Both conditions are associated with negative changes in skeletal muscle health, which can, in turn, lead to impaired physical function, a lowered quality of life, and an increased risk of mortality. Poor nutrition can exacerbate both T2DM and SMA. T2DM and SMA are linked by a vicious cycle of events that reinforce and worsen each other. Muscle insulin resistance appears to be the pathophysiological link between T2DM and SMA. To explore this association, our review (i) compiles evidence on the clinical association between T2DM and SMA, (ii) reviews mechanisms underlying biochemical changes in the muscles of people with or at risk of T2DM and SMA, and (iii) examines how nutritional therapy and increased physical activity as muscle-targeted treatments benefit this population. Based on the evidence, we conclude that effective treatment of patients with T2DM-SMA depends on the restoration and maintenance of muscle mass. We thus propose that regular intake of key functional nutrients, along with guidance for physical activity, can help maintain euglycemia and improve muscle status in all patients with T2DM and SMA.

Arginine and Lysine Supplementation Potentiates the Beneficial β-Hydroxy ß-Methyl Butyrate (HMB) Effects on Skeletal Muscle in a Rat Model of Diabetes

Skeletal muscle is the key tissue for maintaining protein and glucose homeostasis, having a profound impact on the development of diabetes. Diabetes causes deleterious changes in terms of loss of muscle mass, which will contribute to reduced glucose uptake and therefore progression of the disease. Nutritional approaches in diabetes have been directed to increase muscle glucose uptake, and improving protein turnover has been at least partially an oversight. In muscle, β-hydroxy β-methyl butyrate (HMB) promotes net protein synthesis, while arginine and lysine increase glucose uptake, albeit their effects on promoting protein synthesis are limited. This study evaluates if the combination of HMB, lysine, and arginine could prevent the loss of muscle mass and function, reducing the progression of diabetes. Therefore, the combination of these ingredients was tested in vitro and in vivo. In muscle cell cultures, the supplementation enhances glucose uptake and net protein synthesis due to an increase in the amount of GLUT4 transporter and stimulation of the insulin-dependent signaling pathway involving IRS-1 and Akt. In vivo, using a rat model of diabetes, the supplementation increases lean body mass and insulin sensitivity and decreases blood glucose and serum glycosylated hemoglobin. In treated animals, an increase in GLUT4, creatine kinase, and Akt phosphorylation was detected, demonstrating the synergic effects of the three ingredients. Our findings showed that nutritional formulations based on the combination of HMB, lysine, and arginine are effective, not only to control blood glucose levels but also to prevent skeletal muscle atrophy associated with the progression of diabetes.

Lomatogonium rotatum extract alleviates diabetes mellitus induced by a high-fat, high-sugar diet and streptozotocin in rats

BACKGROUND

Lomatogonium rotatum (LR) is traditionally used in Mongolian folk medicine as a hypoglycemic agent, but its evidence-based pharmacological effects and me-chanisms of action have not been fully elucidated.

AIM

To emphasize the hypoglycemic action mechanism of LR in a type 2 diabetic rat model and examine potential biomarkers to obtain mechanistic understanding regarding serum metabolite modifications.

METHODS

A high-fat, high-sugar diet and streptozotocin injection-induced type 2 diabetic rat model was established. The chemical composition of the LR was identified by high performance liquid chromatography. LR extract administrated as oral gavage at 0.5 g/kg, 2.5 g/kg, and 5 g/kg for 4 wk. Anti-diabetic effects of LR extract were evaluated based on histopathological examination as well as the measurement of blood glucose, insulin, glucagon-like peptide 1 (GLP-1), and lipid levels. Serum metabolites were analyzed using an untargeted metabolomics approach.

RESULTS

According to a chemical analysis, swertiamarin, sweroside, hesperetin, coumarin, 1.7-dihydroxy-3,8-dimethoxyl xanthone, and 1-hydroxy-2,3,5 trimethoxanone are the principal active ingredients in LR. An anti-diabetic experiment revealed that the LR treatment significantly increased plasma insulin and GLP-1 levels while effectively lowering blood glucose, total cholesterol, triglycerides, low-density lipoprotein cholesterol, and oral glucose tolerance test compared to the model group. Furthermore, untargeted metabolomic analysis of serum samples detected 236 metabolites, among which 86 were differentially expressed between the model and the LR group. It was also found that LR considerably altered the levels of metabolites such as vitamin B6, mevalonate-5P, D-proline, L-lysine, and taurine, which are involved in the regulation of the vitamin B6 metabolic pathway, selenium amino acid metabolic pathway, pyrimidine metabolic pathway, and arginine and proline metabolic pathways.

CONCLUSION

These findings indicated that LR may have a hypoglycemic impact and that its role may be related to changes in the serum metabolites and to facilitate the release of insulin and GLP-1, which lower blood glucose and lipid profiles.

L-Lysine Ameliorates Diabetic Nephropathy in Rats with Streptozotocin-Induced Diabetes Mellitus

Introduction

Diabetic nephropathy is one of the leading causes of end-stage renal disease worldwide. Uncontrolled hyperglycemia and subsequent production of glycation end-products activate the paths which lead to diabetic nephropathy. The aim of this study was to assess the effects of L-lysine on antioxidant capacity, biochemical factors, kidney function, HSP70 level, and the expression of the TGFβ, VEGF, and RAGE genes in rats with streptozocin-induced diabetes mellitus.

Methods

Thirty-two male Wistar rats were randomly allocated to four eight-rat groups, namely, a healthy group, a diabetic group treated with vehicle (DM + vehicle), a diabetic group treated with L-lysine (DM + Lys), and a healthy group treated with L-lysine (healthy + Lys). Rats in the DM + Lys and the healthy + Lys groups were treated with L-lysine 0.15%. The levels of fasting blood glucose, insulin, HbA_1C, advanced glycation end-products (AGEs), lipid profile, serum creatinine, blood urea nitrogen, glomerular filtration rate, urine microalbumin, oxidative stress parameters, kidney histology and morphology, and TGFβ, VEGF, and RAGE gene expressions were assessed. Findings. An eight-week treatment with L-lysine significantly reduced the levels of fasting blood glucose, AGEs, kidney function parameters, oxidative stress parameters, lipid profile, and the TGFβ, VEGF, and RAGE gene expression and significantly increased the levels of serum insulin and tissue HSP70.

Conclusion

Treatment with L-lysine seems to slow down the progression of diabetic nephropathy.

Widely Targeted Metabolomics Analysis of Soybean and Chickpea and Their Different Advantages and New Functional Compounds for Diabetes

Soybean is widely used as a kind of bean for daily consumption. Chickpea is increasingly utilised because of its good healthcare function. At present, using chickpeas could have better results than soybeans in some areas. Previous studies of the two legumes focused on certain components and failed to fully reveal the differences between the two legumes. Thus, understanding the comprehensive similarities and differences between the two legumes is necessary to apply and develop these legumes effectively. In this study, we performed a UPLC-ESI-MS/MS-based widely targeted metabolomics analysis on two legumes. A total of 776 metabolites (including primary metabolites and secondary metabolites) were detected, which were divided into more than a dozen broad categories. The differential analysis of these metabolites showed that there were 480 metabolites with significant differences in relative contents between the two legumes. Compared with soybean, the expression of 374 metabolites of chickpea was down-regulated and that of 106 metabolites was up-regulated. The metabolic pathway analysis showed significant differences in the flavonoids biosynthesis, phenylpropanoid biosynthesis, linoleic acid metabolism and alkaloid biosynthesis between the two legumes. The advantages and applicability of the two kinds of legumes were confirmed through the analysis of anti-diabetic components. Moreover, some novel compounds (with contents higher than that of soybean) with hypoglycaemic activity were found in chickpea. This study provides an important reference for the in-depth study and comparative application of soybean and chickpea.

Cerebrospinal Fluid Amino Acid Metabolite Signatures of Diabetic Cognitive Dysfunction Based on Targeted Mass Spectrometry

BACKGROUND

Diabetic cognitive dysfunction (DCD) is one of severe diabetic complications and might develop to irreversible dementia. Early diagnosis and detection of DCD is significant for prevention and treatment.

OBJECTIVE

The main objective of this study was to investigate the amino acid profiles of rat with DCD in the cerebrospinal fluid (CSF) to distinguish the early specific biomarkers.

METHODS

In total, rats were assigned into control and model groups. Model was induced by intraperitoneal injection of streptozotocin. The Morris water maze (MWM) method was used to evaluate learning and memory in rats on the 13th week after the model established. CSF samples were collected via cisterna magna puncture at the 0th, 5th, 9th, and 13th week, and amino acids profiling of CSF samples were performed via ultra performance liquid chromatography multiple reaction monitoring mass spectrometry (UPLC-MRM-MS). The amino acid profile was processed through multivariate analysis to identify potential biomarkers, and the related metabolic pathways were analyzed by MetaboAnalyst 5.0.

RESULTS

Compared to the control group, the escape latency of the MWM was significantly prolonged in model group rats (p <  0.05). Different amino acid profiles were obtained between two groups. L-Alanine, L-Glutamine, L-Lysine, L-Serine, and L-Threonine were identified as potential biomarkers for DCD. These biomarkers are principally involved in glycine, serine, and threonine metabolism, aminoacyl-tRNA biosynthesis, alanine, aspartate, and glutamate metabolism, and glyoxylate and dicarboxylate metabolism.

CONCLUSION

There are amino acid biomarkers in the CSF of rat with DCD. The mechanism of DCD is related to those pathways, which provide help for the early diagnosis and treatment and mechanism research.

AGE/Non-AGE Glycation: An Important Event in Rheumatoid Arthritis Pathophysiology

Rheumatoid arthritis (RA) is a chronic inflammatory, autoimmune disease that gradually affects the synovial membrane and joints. Many intrinsic and/or extrinsic factors are crucial in making RA pathology challenging throughout the disease. Substantial enzymatic or non-enzymatic modification of proteins driving inflammation has gained a lot of interest in recent years. Endogenously modified glycated protein influences disease development linked with AGEs/non-AGEs and is reported as a disease marker. In this review, we summarized current knowledge of the differential abundance of glycated proteins by compiling and analyzing a variety of AGE and non-AGE ligands that bind with RAGE to activate multi-faceted inflammatory and oxidative stress pathways that are pathobiologically associated with RA-fibroblast-like synoviocytes (RA-FLS). It is critical to comprehend the connection between oxidative stress and inflammation generation, mediated by glycated protein, which may bind to the receptor RAGE, activate downstream pathways, and impart immunogenicity in RA. It is worth noting that AGEs and non-AGEs ligands play a variety of functions, and their functionality is likely to be more reliant on pathogenic states and severity that may serve as biomarkers for RA. Screening and monitoring of these differentially glycated proteins, as well as their stability in circulation, in combination with established pre-clinical characteristics, may aid or predict the onset of RA.