Effect of the Polyphenol Rich Ethyl Acetate Fraction from the Leaves ofLycium chinenseMill. on Oxidative Stress, Dyslipidemia, and Diabetes Mellitus in Streptozotocin-Nicotinamide Induced Diabetic Rats

The polyphenol/caffeine ratio determines the arousal-inducing properties of the green tea ethanol extract

Green tea (Camellia sinensis L.), one of the most popular beverages worldwide, contains caffeine, a natural stimulant. However, some green tea extracts have been known to possess both hypnotic and arousal effects. This study aimed to identify the components influencing these dual effects using a green tea ethanol extract (GE). Response surface methodology revealed that only some extraction conditions significantly induced arousal effects in ICR mice during the pentobarbital-induced sleep test. Among these, extraction with 95% ethanol for 195 minutes achieved the maximum arousal effect, corresponding to a caffeine content of 58.9 mg g-1, comparable to the effects observed with the reference, 25 mg kg-1 of caffeine. In addition, administration of this GE sample significantly increased wakefulness for 3 hours following treatment in C57BL/6N mice, as confirmed through sleep architecture analysis. A correlation analysis of the total phenolic content (TPC) to caffeine ratio in GE found that the intensity of the arousal-inducing effects varied with TPC (R2 = 0.9428). It was also confirmed that the ratio of EGCG to caffeine, major components of GE, was more closely associated with sleep duration (R2 = 0.9034). L-Theanine, known for its sleep-promoting effects, did not independently affect the arousal effects of GE. However, when combined with EGCG, their total content showed a slightly stronger correlation with sleep duration in relation to the caffeine ratio, compared with that of EGCG/caffeine ratio (R2 = 0.9464). Therefore, the balance between TPC and caffeine appears to modulate the stimulant properties of GE, highlighting its potential as both a stimulant and a mild hypnotic agent. Collectively, these findings provide insights into optimizing GE for tailored functional foods based on its polyphenol/caffeine ratio.

Facile benzothiazole-triazole based thiazole derivatives as novel thymidine phosphorylase and α-glucosidase inhibitors: Experimental and computational approaches

The present study reports the new thiazole (A-L) derivatives based on benzothiazole fused triazole which were synthesized and assessed against thymidine phosphorylase and α-glucosidase enzymes. Several compounds with the same basic structure but different substituents were found to have high activity against the targeted enzymes, while others with the same basic skeleton but different substituents were found to have medium to low activity among the members of tested series. These analogs showed a varied range of inhibition in both case thymidine phosphorylase and alpha glucosidase, A (IC50 = 7.20 ± 0.30 µM and IC50 = 1.30 ± 0.70 µM), B (IC50 = 8.80 ± 0.10 µM and IC50 = 2.10 ± 0.30 µM), C (IC50 = 8.90 ± 0.40 µM and IC50 = 3.20 ± 0.20 µM) and thiazole containing analogs such as G (IC50 = 11.10 ± 0.20 µM and IC50 = 7.80 ± 0.20 µM) and H (IC50 = 12.30 ± 0.30 µM and IC50 = 6.30 ± 0.20 µM). When compared with standard drugs 7-Deazaxanthine, 7DX (IC50 = 10.60 ± 0.50 µM) and acarbose (IC50 = 4.30 ± 0.30 µM) respectively. These analogs were also subjected to molecular docking studies which indicated the binding interaction of molecules with active sites of the enzyme and strengthen the drug profile of these compounds. ADMET studies also predict the drug-like properties of these compounds, with no violations of drug likeness rules.

Insights into the phytochemical profiling, antidiabetic and antioxidant potentials of Lepionurus sylvestris Blume extract in fructose/streptozotocin-induced diabetic rats

In this study, the antidiabetic activities of Lepionurus sylvestris Blume extract (LSB) in rats was investigated. The in vitro antidiabetic properties of LSB was evaluated using α-amylase, α-glucosidase and DPP-IV inhibitory assays, while the antioxidant assay was analysed using DPPH, ABTS and FRAP assays. Type 2 diabetes was with high-fructose/streptozotocin, and the diabetic animals were treated with LSB for 5 weeks. At the end of the experiment, the effects of LSB were evaluated via insulin level, lipid profile and hepatorenal function biomarkers. The level of oxido-inflammatory parameters, histopathology and insulin immunohistochemical staining in the pancreas was evaluated. Diabetic rats manifested significant increases in the blood glucose level, food/water intake, lipid profiles, hepatorenal function biomarkers, as well as a marked decreases in the body weight and serum insulin levels. Histopathological and insulin immunohistochemical examination also revealed decreased pancreatic beta cells and insulin positive cells, respectively. These alterations were associated with significant increases in malondialdehyde, TNF-α and IL-1β, in addition to significant declines in GSH, SOD and CAT activities. LSB significantly reduced blood glucose level, glucose intolerance, serum lipids, restored altered hepatorenal and pancreatic functions in the treated diabetic rats. Further, LSB showed antioxidant and anti-inflammatory activities by reducing malondialdehyde, TNF-α, IL-1β, and increasing antioxidant enzymes activities in the pancreatic tissues. A total of 77 secondary metabolites were tentatively identified in the UPLC-Q-TOF-MS analysis of LSB. Overall, these findings provides insight into the potentials of LSB as an antidiabetic agent which may be associated to the plethora bioactive compounds in the plant.

Indole-pyridine carbonitriles: multicomponent reaction synthesis and bio-evaluation as potential hits against diabetes mellitus

Background: Diabetes mellitus is a significant health disorder; therefore, researchers should focus on discovering new drug candidates. Methods: A series of indole-pyridine carbonitrile derivatives, 1-34, were synthesized through a one-pot multicomponent reaction and evaluated for antidiabetic and antioxidant potential. Results: In this library, 12 derivatives - 1, 2, 4, 5, 7, 8, 10-12, 14, 15 and 31 - exhibited potent inhibitory activities against α-glucosidase and α-amylase enzymes, in comparison to acarbose (IC50 = 14.50 ± 0.11 μM). Furthermore, kinetics, absorption, distribution, metabolism, excretion and toxicity and molecular docking studies were used to interpret the type of inhibition, binding energies and interactions of ligands with target enzymes. Conclusion: These results indicate that the compounds may be promising hits for controlling diabetes mellitus and its related complications.

Encapsulation of Polygonum bistorta root phenolic compounds as a novel phytobiotic and its protective effects in the mouse model of enteropathogenic Escherichia coli infection

BACKGROUND

Microencapsulation technology is the fundamental delivery system for encapsulating the natural bioactive compounds especially phenolic in order to developing bioavailability, stability and controlling release. This study was conducted to determine the antibacterial and health-promoting potential of the phenolic rich extract (PRE)-loaded microcapsules obtained from Polygonum bistorta root as a dietary phytobiotic in mice challenged by enteropathogenic Escherichia coli (E. coli).

METHOD

The PRE was obtained from Polygonum bistorta root using fractionation by different polarity solvents and the highest PRE was encapsulated by the combination of modified starch, maltodextrin, and whey protein concentrate as wall materials using a spray dryer. Then, the physicochemical characterization (particle size, zeta potential, Morphology and polydispersity index) of microcapsules have been assessed. For the invivo study, 30 mice at five treatment were designed and antibacterial properties were analyzed. Furthermore, relative fold changes in the ileum population of E. coli was investigated using Real time PCR.

RESULTS

The encapsulation of PRE resulted in the production of phenolic enriched extract-loaded microcapsules (PRE-LM) with a mean diameter of 330 nm and relatively high entrapment efficiency (87.2% w/v). The dietary supplementation of PRE-LM improved weight gain, liver enzymes, gene expression, morphometric characteristics of the ileum and decreased the population of E. coli present in the ileum significantly (p < 0.05).

CONCLUSION

Our funding suggested PRE-LM as a promising phytobiotic against E. coli infection in mice.

Rheum ribes extract-loaded nanoliposome as a novel phytogenic antibiotic alternative in mice challenged by Escherichia coli (O157:H7)

This study was performed to compare the noncapsulated with nanoliposome-encapsulated phenolic-rich fraction (PRF) obtained from Rheum ribes as a dietary additive and to assess their health-promoting potentials in the mice infected by enteropathogenic Escherichia coli (O157:H7). Upon fractionation, the ethyl acetate fraction with 46.9 ± 2.17 mg GAE/g DW was found as a highest phenolic content. The PRF successfully loaded into nanoliposome structure with a nanometer in size (193.2 nm) and spherical shape and homogeneous dispersion. The gallic acid, salicylic acid, caffeic acid, cinnamic acid, catechin, ellagic acid, and ferulic acid are bioactive phenolics present in the nanoliposome-loaded PRF; however, the main bioactive compounds are cinnamic acid (911 μg/g DW) and ellagic acid (826 μg/g DW). The infection caused by E. coil impaired the weight gain and food intake, liver function, morpho structural characteristics of jejunum, upregulated the expression of inflammatory genes (Cox2, iNOS), downregulation of antioxidant-related genes (SOD, GPX), and increased the ileal population of E. coil. The addition of nonencapsulated PRF and nanoliposome-encapsulated PRF at the concentration of 10 mg TPC/kg BW/day improved these parameters although the nanoliposome-encapsulated PRF revealed more potential as compared with the nonencapsulated PRF in improving the health parameters in mice. The higher health-promoting activity of nanoliposome-encapsulated PRF could be associated with its enhanced intestinal absorption, bioavailability, bioaccessibility, and bioactivity. Consequently, the nanoliposome-encapsulated PRF could be considered as a promising phytobiotic against E. coil infection in mice.

Nano-liposomal encapsulation of Artemisia aucheri phenolics as a potential phytobiotic against Campylobacter jejuni infection in mice

Background

Artemisia aucheri contains antibacterial phenolic compounds. The current work was implemented to evaluate the effectiveness of a nanoliposome-encapsulated phenolic-rich fraction (PRF-NLs), as a dietary phytobiotic derived from Artemisia aucheri's areal parts, on the inhibition of enteropathogenic Campylobacter jejuni (C. jejuni) infection in mice.

Methods

The phenolic-rich fraction was loaded into the nanoliposome structure to obtain a nanometer-scale size liposome with homogenous dispersion. Next, 40 white male balb/c mice were assigned to 4 treatment groups. The PRF-NLs antibacterial potential was evaluated by evaluating the blood parameters, liver lipid peroxidation, and gene expression profiling in the mice challenged by C. jejuni infection.

Results

Mice infected by C. jejuni showed impairment in food intake, weight gain, liver function, ileum morphometric features, and ileum tissue inflammation. The diet of fortified food with the nonencapsulated and nanoliposome-encapsulated phenolic compounds was found to improve these parameters at 10 mg TPC/kg BW/day concentration. Our data indicated that the nanoliposome-encapsulated PRF was more effective in promoting the health parameters in mice as compared to nonencapsulated PRF.

Conclusion

It could be concluded that the liposomal encapsulation can promote the solubility, availability, and effectiveness of Artemisia aucheri phenolic compounds playing a key role as phytobiotic in mice intervened by enteropathogenic C. jejuni.

Ameliorative potentials of the ethanolic extract from Lycium chinense leaf extract against diabetic cardiomyopathy. Insight into oxido-inflammatory and apoptosis modulation

The prevalence of cardiovascular complications in diabetes has become one of the major cause of diabetes related morbidity/mortality. The onset and progression of diabetic cardiomyopathy (DCM) has been majorly linked to lipid alterations, oxidative stress, inflammation and apoptosis. This present study investigated the cardioprotective role of Lycium chinense leaf extract (LCME) in fructose/streptozotocin induced diabetic rats. Diabetic animals were orally gavaged with LCME (100 and 400 mg/kg) for five weeks. The results indicated that diabetic rats showed increased blood glucose concentration, serum cardiac function markers (troponin T, creatine kinase-MB, aspartate aminotransferase and lactate dehydrogenase) and lipid profile (triglycerides and cholesterol). In addition, the cardiac tissues of diabetic rats showed increased levels of nuclear factor-κB (NF-κB), tumor necrosis factor alpha (TNF-α), interleukin 1 beta (IL 1β), interleukin 6 (IL-6), caspase-3 and malondialdehyde as well as significantly reduced activities of catalase, superoxide dismutase, reduced glutathione and glutathione peroxidase. LCME significantly ameliorated hyperglycemia and markedly decreased serum concentrations of troponin T, creatine kinase-MB, aspartate aminotransferase and lactate dehydrogenase, triglycerides and cholesterol. Furthermore, LCME notably suppressed cardiac oxido-inflammatory mediators and boosted cardiac antioxidant defense. Histopathologically, LCME restored cardiac structural alterations and also suppressed the immunohistochemical expression of collagen IV, smooth muscle alpha-actin (α-SMA) and p53, while Bcl2 expression was significantly increased. In conclusion, our result indicated that LCME protected against diabetic cardiomyopathy suppressing oxidative stress, inflammation, apoptosis and fibrosis.

Micronized Dietary Okara Fiber: Characterization, Antioxidant, Antihyperglycemic, Antihyperlipidemic, and Pancreato-Protective Effects in High Fat Diet/Streptozotocin-Induced Diabetes Mellitus

Diabetes mellitus (DM) is a lifelong devastating and debilitating disease with serious chronic complications. Okara is a byproduct generated from soymilk or tofu production and it has been reported to have antioxidant and lipid-lowering effects. However, the antidiabetic effects and pancreatic β-cells' secretory functions of micronized okara fiber (MOF) have not been reported. Therefore, this study explored the antidiabetic effects and modulatory potentials of MOF on pancreatic β-cells' secretory functions in a high fat/high sugar/streptozotocin rat model of diabetes mellitus. Fiber-rich okara was prepared by removing fat and proteins from freshly obtained okara, followed by micronization. Fiber-rich okara was prepared, micronized, and characterized for hydrophobicity, thermal stability, structure-function relationship, and antioxidant potentials. We then established a rat model of DM and MOF and two doses (100 and 400 mg kg^-1) were administered to see its anti-DM effect. Four weeks of MOF supplementation significantly reduced blood glucose, increased serum insulin level, improved hepatorenal functions, glucose tolerance, and regenerated pancreatic β-cells in the treated DM rats. Furthermore, MOF significantly improved the pancreatic antioxidant defense system by significantly elevating glutathione peroxidase, catalase, and superoxide dismutase activities while depleting the malonaldehyde level in the pancreas of the treated diabetic rats. Our results indicated that MOF ameliorated DM by impeding hyperglycemia, hyperlipidemia, and oxidative stress and enhancing the secretory functions of the beta cells, suggesting that MOF might be used as a protective nutrient in DM.

UHPLC-ESI-QTOF-MS2 analysis of Acacia pennata extract and its effects on glycemic indices, lipid profile, pancreatic and hepatorenal alterations in nicotinamide/streptozotocin-induced diabetic rats

Diabetes mellitus (DM) is a chronic disorder associated with severe metabolic derangement and comorbidities. The constant increase in the global population of diabetic patients coupled with some prevailing side effects associated with synthetic antidiabetic drugs has necessitated the urgent need for the search for alternative antidiabetic regimens. This study investigated the antidiabetic, antioxidant, and pancreatic protective effects of the Acacia pennata extract (APE) against nicotinamide/streptozotocin induced DM in rats. The antidiabetic activity of APE was evaluated and investigated at doses of 100 and 400 mg/kg body weight, while metformin (150 mg/kg bw) was used as a standard drug. APE markedly decreased blood glucose level, homeostatic model assessment for insulin resistance, serum total cholesterol, triglycerides, low‐density lipoprotein, blood urea nitrogen, creatinine, alanine transaminase, aspartate transaminase, and alanine phosphatase levels. Additionally, treatment with APE increased the body weight, serum insulin concentration, and high‐density lipoprotein. Moreover, activities of pancreatic superoxide dismutase, catalase, and glutathione peroxidase were increased, while the altered pancreatic architecture in the histopathological examination was notably restored in the treated rats. Ultra‐high performance liquid chromatography combined with electrospray ionization quadrupole time‐of‐flight mass spectrometry (UHPLC‐ESI‐QTOF‐MS) analysis of APE showcases the prevailing presence of polyphenolic compounds. Conclusively, this study showed the beneficial effects of the Acacia pennata in controlling metabolic derangement, pancreatic and hepatorenal dysfunction in diabetic rats.

Nanoliposome-encapsulated phenolic-rich fraction from Alcea rosea as a dietary phytobiotic in mice challenged by Escherichia coli

Purpose

This research was performed to evaluate the antibacterial and health-promoting potentials of nanoliposome-encapsulated phenolic-rich fraction (PRF) from Alcea rosea leaves, as a dietary phytobiotic, in mice as challenged by enteropathogenic Escherichia coli (E. coli; O157: H7).

Method

The PEF was encapsulated in nanoliposomes (PEF-NLs), and the phenolic profiling of PEF-NLs was confirmed by HPLC. Next, 40 white male balb/c mice were assigned to four treatment groups to assess the antibacterial potential of PEF-NLs by measuring the blood parameters and the liver’s lipid peroxidation in the mice as a result of the infection caused by E. coli. Finally, the expression of cyclooxygenase 2 (COX2), inducible nitric oxide synthase (iNOS), superoxide dismutase (SOD), and glutathione peroxidase (GPx) were determined in the miceʼs ileum tissues. A real-time PCR was used to analyze the relative fold changes in the population of E. coli in the ileum.

Results

The overall results demonstrated that the nanoliposome-loaded PRF contained gallic acid, salicylic acid, pyrogallol, cinnamic acid, catechin, naringin, and ferulic acid. The E. coli intervention impaired the mice's weight gain, food intake, liver enzymes, lipid peroxidation, and the ileum’s morphometric characteristics. The challenge also upregulated the inflammatory genes (COX2, iNOS), downregulated the antioxidant-related genes (SOD and GPx), and increased the population of E. coli in the ileum. The dietary inclusion of the nonencapsulated PRF and the nanoliposome-encapsulated PRF, at the concentration of 10 mg TPC/kg BW/day, improved these parameters. However, compared to nonencapsulated PRF, the nanoliposome-encapsulated PRF appeared to be more effective in improving the health parameters in mice.

Conclusion

As a promising phytobiotic, the nanoliposome-encapsulated PRF could play a critical role against the E. coli infection in mice probably due to the increase in the higher intestinal solubility, bioavailability, and absorption of phenolic compounds encapsulated in the nanoliposome carrier.

Role of Polyphenol in Regulating Oxidative Stress, Inflammation, Fibrosis, and Apoptosis in Diabetic Nephropathy

Diabetic nephropathy (DN) is known as one of the driving sources of end-stage renal disease (ESRD). DN prevalence continues to increase in every corner of the world andthat has been a major concern to healthcare professionals as DN is the key driver of diabetes mellitus (DM) morbidity and mortality. Hyperglycaemia is closely connected with the production of reactive oxygen species (ROS) that cause oxidative stress response as well as numerous cellular and molecular modifications. Oxidative stress is a significant causative factor to renal damage, as it can activate other immunological pathways, such as inflammatory, fibrosis, and apoptosis pathways. These pathways can lead to cellular impairment and death as well as cellular senescence. Natural substances containing bioactive compounds, such as polyphenols, have been reported to exert valuable effects on various pathological conditions, including DM. The role of polyphenols in alleviating DN conditions has been documented in many studies. In this review, the potential of polyphenols in ameliorating the progression of DN via modulation of oxidative stress, inflammation, fibrosis, and apoptosis, as well as cellular senescence, has been addressed. This information may be used as the strategies for the management of DN and development as nutraceutical products to overcome DN development.

Securidaca inappendiculata Polyphenol Rich Extract Counteracts Cognitive Deficits, Neuropathy, Neuroinflammation and Oxidative Stress in Diabetic Encephalopathic Rats via p38 MAPK/Nrf2/HO-1 Pathways

Diabetic encephalopathy is one of the serious emerging complication of diabetes. Securidaca inappendiculata is an important medicinal plant with excellent antioxidant and anti-inflammatory properties. This study investigated the neuroprotective effects of S. inappendiculata polyphenol rich extract (SiPE) against diabetic encephalopathy in rats and elucidated the potential mechanisms of action. Type 2 diabetes mellitus (T2DM) was induced using high fructose solution/intraperitoneal injection of streptozotocin and the diabetic rats were treated with SiPE (50, 100 and 200 mg/kg) for 8 weeks. Learning and memory functions were assessed using the Morris water and Y maze tests, depressive behaviour was evaluated using forced swimming and open field tests, while neuropathic pain assessment was assessed using hot plate, tail immersion and formalin tests. After the experiments, acetylcholinesterase (AChE), oxidative stress biomarkers and proinflammatory cytokines, caspase-3 and nuclear factor kappa-light-chain-enhancer of activated B (NF-κB) were determined by ELISA kits. In addition, the expression levels of p38, phospho-p38 (p-p38), nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) were determined by western blot analyses. The results indicated that SiPE administration significantly lowered blood glucose level, attenuated body weight loss, thermal/chemical hyperalgesia, improved behavioural deficit in the Morris water maze, Y maze test and reduced depressive-like behaviours. Furthermore, SiPE reduced AChE, caspase-3, NF-κB, malonaldehyde malondialdehyde levels and simultaneously increased antioxidant enzymes activity in the brain tissues of diabetic rats. SiPE administration also significantly suppressed p38 MAPK pathway and upregulated the Nrf2 pathway. The findings suggested that SiPE exerted antidiabetic encephalopathy effects via modulation of oxidative stress and inflammation.

Traditionally Used Plants in the Treatment of Diabetes Mellitus: Screening for Uptake Inhibition of Glucose and Fructose in the Caco2-Cell Model

The traditional use of plants and their preparations in the treatment of diseases as a first medication in the past centuries indicates the presence of active components for specific targets in the natural material. Many of the tested plants in this study have been traditionally used in the treatment of Diabetes mellitus type 2 and associated symptoms in different cultural areas. Additionally, hypoglycemic effects, such as a decrease in blood glucose concentration, have been demonstrated in vivo for these plants. In order to determine the mode of action, the plants were prepared as methanolic and aqueous extracts and tested for their effects on intestinal glucose and fructose absorption in Caco2 cells. The results of this screening showed significant and reproducible inhibition of glucose uptake between 40 and 80% by methanolic extracts made from the fruits of Aronia melanocarpa, Cornus officinalis, Crataegus pinnatifida, Lycium chinense, and Vaccinium myrtillus; the leaves of Brassica oleracea, Juglans regia, and Peumus boldus; and the roots of Adenophora triphylla. Furthermore, glucose uptake was inhibited between 50 and 70% by aqueous extracts made from the bark of Eucommia ulmoides and the fruit skin of Malus domestica. The methanolic extracts of Juglans regia and Peumus boldus inhibited the fructose transport between 30 and 40% in Caco2 cells as well. These findings can be considered as fundamental work for further research regarding the treatment of obesity-correlated diseases, such as Diabetes mellitus type 2.

Exploring efficacy of indole-based dual inhibitors for α-glucosidase and α-amylase enzymes: In silico, biochemical and kinetic studies

α-Glucosidase and α-amylase are enzymes which are associated with diabetic II. These enzymes break macromolecules of sugar into monosugar molecules which is soluble in body, hence increase the sugar level in blood. There is need to develop economical and save inhibitors to prevent them from breaking sugar macromolecules to soluble molecules which will control the level of sugar in blood. Therefore, we synthesized indole-based derivatives (1-18) and evaluated as dual inhibitor for α-glucosidase and α-amylase. These chemical scaffolds were built with variation in aryl ring which were found active with good to moderate activity for α-glucosidase having IC50 value ranging from 13.99 ± 0.10 to 59.09 ± 0.30 μM when compared with standard acarbose with IC50 of 11.29 ± 0.10 μM; for α-amylase IC50 value ranging from 13.14 ± 0.10 to 58.99 ± 0.30 μM when compared with the standard acarbose with IC50 of 11.12 ± 0.10 μM. Structure activity relationship (SAR) has been established for all compounds. Enzymatic kinetic study and molecular docking study have been carried out to investigate the binding interactions α-glucosidase and α-amylase enzyme.

Synthesis, in vitro α-amylase inhibitory, and radicals (DPPH & ABTS) scavenging potentials of new N-sulfonohydrazide substituted indazoles

Over-expression of α-amylase enzyme causes hyperglycemia which lead to many physiological complications including oxidative stress, one of the most commonly associated problem with diabetes mellitus. Marketed α-amylase inhibitors such as acarbose, voglibose, and miglitol used to treat type-II diabetes mellitus, but also linked to several harmful effects. Therefore, it is essential to explore new and nontoxic antidiabetic agents with additional antioxidant properties. In this connection, a series of new N-sulfonohydrazide substituted indazoles 1-19 were synthesized by multistep reaction scheme and assessed for in vitro α-amylase inhibitory and radical (DPPH and ABTS) scavenging properties. All compounds were fully characterized by different spectroscopic techniques including 1H, 13C NMR, EI-MS, HREI-MS, ESI-MS, and HRESI-MS. Compounds showed promising α-amylase inhibitory activities (IC50 = 1.23 ± 0.06-4.5 ± 0.03 µM) as compared to the standard acarbose (IC50 1.20 ± 0.09 µM). In addition to that all derivatives were found good to moderate scavengers of DPPH (IC50 2.01 ± 0.13-5.3 ± 0.11) and ABTS (IC50 = 2.34 ± 0.07-5.5 ± 0.07 µM) radicals, in comparison with standard ascorbic acid having scavenging activities with IC50 = 1.99 ± 0.09 µM, and IC50 2.03 ± 0.11 µM for DPPH and ABTS radicals. In silico molecular docking study was conducted to rationalize the binding interaction of α-amylase enzyme with ligands. Compounds were observed as mixed type inhibitors in enzyme kinetic characterization.

Synthesis of new indazole based dual inhibitors of α-glucosidase and α-amylase enzymes, their in vitro, in silico and kinetics studies

The current study describes the discovery of novel inhibitors of α-glucosidase and α-amylase enzymes. For that purpose, new hybrid analogs of N-hydrazinecarbothioamide substituted indazoles 4-18 were synthesized and fully characterized by EI-MS, FAB-MS, HRFAB-MS, 1H-, and 13C NMR spectroscopic techniques. Stereochemistry of the imine double bond was established by NOESY measurements. All derivatives 4-18 with their intermediates 1-3, were evaluated for in vitro α-glucosidase and α-amylase enzyme inhibition. It is worth mentioning that all synthetic compounds showed good inhibition potential in the range of 1.54 ± 0.02-4.89 ± 0.02 µM for α-glucosidase and for α-amylase 1.42 ± 0.04-4.5 ± 0.18 µM in comparison with the standard acarbose (IC50 value of 1.36 ± 0.01 µM). In silico studies were carried out to rationalize the mode of binding interaction of ligands with the active site of enzymes. Moreover, enzyme inhibitory kinetic characterization was also performed to understand the mechanism of enzyme inhibition.

Glucose-lowering effect of Gryllus bimaculatus powder on streptozotocin-induced diabetes through the AKT/mTOR pathway

This study was carried out to elucidate the antidiabetic effects of Gryllus bimaculatus powder using a streptozotocin (STZ)-induced rat model of type I diabetes. Administration of the insect powder significantly rescued representative diabetes markers (i.e., insulin and C-peptide) in STZ-treated rats. Improved glucose tolerance test (GTT) and insulin tolerance test (ITT) results were also observed, indicating that Gryllus bimaculatus powder exerts antidiabetic effects. Gryllus bimaculatus powder administration rescued STZ-induced alterations in both islet morphology and insulin staining patterns. The extract increased antiapoptotic Bcl2 expression and decreased proapoptotic Bax and active caspase 3 expressions. In addition, the Gryllus bimaculatus powder supplementation enhanced AKT/mTOR pathway, a key marker of the state of anabolic metabolism, and its downstream effector, mTOR. Collectively, our results suggest that Gryllus bimaculatus contributes to the maintenance of pancreatic β-cell function and morphology against a diabetic state through the regulations against apoptosis and anabolic metabolism.

Lycium barbarum L. leaves ameliorate type 2 diabetes in rats by modulating metabolic profiles and gut microbiota composition

The leaf of Lycium barbarum L. (LLB) has been widely used as a tea, vegetable, and herb in China and Southeast Asia for centuries; this is because of the hypoglycemic effect it has, but the mechanism behind this effect is still unclear. In this study, a type 2 diabetic mellitus (T2DM) rat model, induced by a high-fat diet combined with low-dose streptozotocin (STZ) injections, was adopted. The biochemical index was determined and the histopathological and metabolomics analyses of serum and urine and 16S rDNA sequencing of the gut microbiota were performed. We evaluated the hypoglycemic effects and the mechanism of action of the water extract from LLB, which contained neochlorogenic acid, chlorogenic acid, caffeic acid, and rutin (up to 6.06%). The relationships between biochemical indexes, serum and urine metabolites, and gut microbiota were analyzed. The results showed that the LLB extract could noticeably modulate the levels of blood glucose and lipids in diabetic rats as well as repair injuries in livers, kidneys and pancreas. The changes in serum and urine metabolites caused by T2DM were reversed after the administration of LLB; these changes were found to mainly be correlated with the following pathways: nicotinate and nicotinamide metabolism, arachidonic acid metabolism, and purine metabolism. Sequencing of the 16S rDNA from fecal samples showed that the LLB extract could reverse the gut microbiota dysbiosis that T2DM had induced. Therefore, we conclude that T2DM, which altered the metabolic profiles and gut microbiota, could be alleviated effectively using the LLB extract.

Analysis of phenolic acids and flavonoids in leaves of Lycium barbarum from different habitats by ultra-high-performance liquid chromatography coupled with triple quadrupole tandem mass spectrometry

The leaves of Lycium barbarum (LLB) have been utilized as crude drugs and functional tea for human health in China and Southeast Asia for thousands of years. To control its quality, a rapid and sensitive ultra-high-performance liquid chromatography coupled with triple quadrupole tandem mass spectrometry method was established and validated for the first time for simultaneous determination of 10 phenolic acids and flavonoids (including neochlorogenic acid, protocatechuic aldehyde, p-hydroxybenzoic acid, chlorogenic acid, cryptochlorogenic acid, caffeic acid, p-coumaric acid, ferulic acid, rutin and kaempferol-3-O-rutinoside) in LLB. The separation was performed on an Acquity UPLC C₁₈ chromatographic column (100 × 2.1 mm internal diameter, 1.7 μm particle size) with 0.1% formic acid in water (A)-acetonitrile (B) as the mobile phase under gradient elution. Multiple reaction monitoring mode was adopted to simultaneously monitor the target components. The developed method was fully validated in terms of linearity (r²  ≥ 0.9860), precision (RSD ≤ 6.58%), repeatability (RSD ≤ 6.60%), stability (RSD ≤ 6.17%), recovery (95.56-108.06%, RSD ≤ 4.64%) and limit of detection (0.021-0.664 ng/mL) and limit of quantitation (0.069-2.210 ng/mL), and then successfully applied to evaluate the quality of 64 batches of LLB collected from 41 producing areas in four different provinces of China. The results showed that the LLB, especially collected from Inner Mongolia regions, were rich in the phenolic acids and flavonoids. Rutin, kaempferol-3-O-rutinoside and chlorogenic acid are the predominant compounds contained in LLB. The above findings will provide helpful information for the effective utilization of LLB.

Rhinacanthins-rich extract and rhinacanthin C ameliorate oxidative stress and inflammation in streptozotocin-nicotinamide-induced diabetic nephropathy

In this present study, rhinacanthins-rich extract (RRE) and rhinacanthin C (RC) the main bioactive constituent of Rhinacanthus nasutus was investigated for their protective effect against diabetic nephropathy (DN). Diabetes was induced by administering nicotinamide (100 mg/kg, i.p.)/streptozotocin (60 mg/kg, i.p.) and diabetic rats were orally administered with RRE and RC for 4 weeks. RRE and RC significantly reduced the kidney index, renal oxidative stress markers, and pro-inflammatory cytokines. Furthermore, RRE and RC increased renal levels of glutathione, superoxide dismutase, catalase, and attenuated diabetic induced renal damages. In conclusion, RRE and RC confer protective effect against DN through the inhibition of oxidative stress and inflammation and could be a potential medicinal or nutritional supplement for the prevention of DN. PRACTICAL APPLICATIONS: Rhinacanthus nasutus is a medicinal plant that is extensively used in Thai traditional medicine as an antibacterial, antifungal, antidiabetic, and anti-inflammatory agent. The plant is rich in naphthoquinones, which confer it with several excellent bioactivities. The rich extract of the leaves was prepared with three major bioactive components and the extract was evaluated for its renoprotective effect in diabetic rats. The results from this study provides valuable pharmacological information that supports the use of the plant, especially the rich extract in the prevention and treatment of diabetes and diabetic complications.

Effects of Pistacia atlantica on Oxidative Stress Markers and Antioxidant Enzymes Expression in Diabetic Rats

INTRODUCTION

Diabetes mellitus (DM) affects many patients all over the world. It involves different parts of the body, such as brain, eyes, kidneys, vessels, and so on. The lack of balance between free radicals and antioxidants is a possible mechanism involved in the pathogenesis of diabetes. Antioxidant treatment, especially natural forms, can be a beneficial solution. Therefore, we evaluated the effects of Pistacia atlantica oleoresin (PAO) on oxidative stress markers and antioxidant enzymes expression in diabetic rats.

METHOD

Fifty adult male Wistar rats were allotted randomly into five groups as follow: control group, diabetic control group, glibenclamide control group, diabetic glibenclamide group, diabetic treated group with 200 mg/kg PAO. Then PAO was prepared and analyzed by gas chromatography/mass spectroscopy (GC/MS). LD50 was also estimated for essential oil. Oxidative stress markers and antioxidant enzyme including malondialdehyde (MDA), glutathione (GSH), glutathione peroxidase (GPx), catalase (CAT), and superoxide dismutase (SOD) were also measured. The expression of GPx, CAT, and SOD genes was investigated using real-time polymerase chain reaction (PCR).

RESULTS

The main constituents of essential oil gum were beta-pinene (29.38%), followed by alpha-pinene (18.15%), myrcene (7.36%), trans-pinocarveol (7.15%), and camphene (4.12%). Diabetes induced an increased level of MDA (69.92 ± 3.92 vs. 43.76 ± 3.73) and decreased levels of GSH (2.57 ± 0.40 vs. 7.05 ± 1.59), GPx (11.66 ± 2.2 vs. 16.38 ± 2.1), CAT (12.17 ± 3.38 vs. 18.7 ± 2.66), and SOD (0.78 ± 0.67 vs. 2.41 ± 0.46). In contrast, PAO treatment significantly decreased MDA (54.59 ± 12.54 vs. 69.92 ± 3.92) and increased GSH (4.5 ± 0.89 vs. 2.57 ± 0.40), GPx (25.86 ± 5.37 vs. 11.66 ± 2.2), CAT (22.69 ± 0.36 vs. 12.17 ± 3.38), and SOD (3.65 ± 1.08 vs. 0.78 ± 0.67) (p < 0.05). Moreover, our results indicated that both GPx and CAT mRNA levels significantly increased approximately 4.46 and 6.23 times in rats fed with 200 mg/kg of PAO, more than that of the healthy control group, respectively (p < 0.01 and p < 0.001, respectively). Also, the average expression level of SOD was also significantly 1.57 higher in rats fed with 200 mg/kg of PAO in comparison to the diabetic control group (p < 0.05).

CONCLUSION

The results indicated that PAO could be propose as an agent that protects the body against diseases that are associated with oxidative stress.

Preventive role of Pycnogenol® against the hyperglycemia-induced oxidative stress and DNA damage in diabetic rats

Diabetes mellitus, a complex progressive metabolic disorder, leads to some oxidative stress related complications. Pycnogenol^® (PYC), a plant extract obtained from Pinus pinaster, has been suggested to be effective in many diseases including diabetes, cancer, inflammatory and immune system disorders. The mechanisms underlying the effects of PYC in diabetes need to be elucidated. The aim of this study was to determine the effects of PYC treatment (50 mg/kg/day, orally, for 28 days) on the DNA damage and biochemical changes in the blood, liver, and kidney tissues of experimental diabetic rats. Changes in the activities of catalase, superoxide dismutase, glutathione peroxidase, glutathione reductase, and glutathione-S-transferase enzymes, and the levels of 8-hydroxy-2'-deoxyguanosine, total glutathione, malondialdehyde, insulin, total bilirubin, alanine aminotransferase, aspartate aminotransferase, gamma-glutamyl transferase, high density lipoprotein, low density lipoprotein, total cholesterol, and triglyceride were evaluated. DNA damage was also determined in the whole blood cells and the liver and renal tissue cells using the alkaline comet assay. PYC treatment significantly ameliorated the oxidative stress, lipid profile, and liver function parameters as well as DNA damage in the hyperglycemic rats. The results show that PYC treatment might improve the hyperglycemia-induced biochemical and physiological changes in diabetes.

Lycium chinense leaves extract ameliorates diabetic nephropathy by suppressing hyperglycemia mediated renal oxidative stress and inflammation

Diabetic nephropathy is one of the most serious and most frequently encountered diabetic complication, accounting for the highest cause of end-stage renal disease. This present study was aimed at exploring the protective/attenuative effect of Lycium chinense leaf extract (MELC) on streptozotocin induced diabetic nephropathy in experimental Sprague Dawley rats. The oral administration of diabetic rats with MELC markedly ameliorated renal dysfunction as observed in the significant reduction in the serum levels of creatinine, blood urea nitrogen (BUN), albumin and TGF-β1 as compared to the untreated diabetic control rats. In addition, the elevated levels of renal oxidative stress markers and pro-inflammatory parameters (GSH, SOD, CAT, MDA, TNF-α, IL-6 and IL-1β) were significantly reduced in MELC treated diabetic rats. The results obtained in this study suggests that L. chinense leaf might have the potential as possible pharmacological agent against diabetic nephropathy by suppressing renal oxidative stress and inflammation.