Small Molecule Kaempferol Promotes Insulin Sensitivity and Preserved Pancreatic β -Cell Mass in Middle-Aged Obese Diabetic Mice

Bryophyllum pinnatum (Lam.) Oken: unravelling therapeutic potential and navigating toxicity

Bryophyllum pinnatum (Lam.) Oken, a multipurpose medicinal herb, has drawn much interest for its therapeutic qualities from both traditional and modern medicine systems. Many active secondary metabolites, such as bufadienolides, triterpenes, phenols, alkaloids, glycosides, lipids, flavonoids, and organic acids, are responsible for the plant's curative properties. B. pinnatum exhibits a noteworthy significance in oncological research by exhibiting its ability to modify numerous pathways, which may suggest a potential anticancer impact. The herb is recommended for treating lithiasis, a common cause of renal failure, due to its effectiveness in dissolving stones and avoiding crystal formation. The plant has a major impact on diabetes, especially type II diabetes. Moreover, the versatility of B. pinnatum extends to its examination in connection to COVID-19. However, caution is warranted, as B. pinnatum has been reported to possess toxicity attributed to the presence of bufadienolides in its metabolic profile. A comprehensive investigation is essential to thoroughly understand and confirm the synthesis of potentially hazardous compounds. This is crucial for minimizing their presence and ensuring the safe consumption of B. pinnatum among diverse populations of organisms. This review highlights the various medical uses of B. pinnatum, including its ability to effectively treat kidney and liver diseases, as well as its anti-leishmanial, neuropharmacological, antibacterial, immunosuppressive, anti-tumour, and cytotoxic effects. While extensively employed in both traditional and scientific domains, the plant's complete medicinal potential, molecular mechanisms, safety profile, and pharmacodynamics remain ambiguous, rendering it an ideal candidate for pioneering research endeavours.

Clinical applications and mechanism insights of natural flavonoids against type 2 diabetes mellitus

Diabetes is a complex disease that affects a large percentage of the world's population, and it is associated with several risk factors. Self-management poses a significant challenge, but natural sources have shown great potential in providing effective glucose reducing solutions. Flavonoids, a class of bioactive substances found in different natural sources including medicinal plants, have emerged as promising candidates in this regard. Indeed, several flavonoids, including apigenin, arbutin, catechins, and cyanidin, have demonstrated remarkable anti-diabetic properties. The clinical effectiveness of these flavonoids is linked to their potential to decrease blood glucose concentration and increase insulin concentration. Thus, the regulation of certain metabolic pathways such as glycolysis and neoglycogenesis has also been demonstrated. In vitro and in vivo investigations revealed different mechanisms of action related to flavonoid compounds at subcellular, cellular, and molecular levels. The main actions reside in the activation of glycolytic signaling pathways and the inhibition of signaling that promotes glucose synthesis and storage. In this review, we highlight the clinical efficiency of natural flavonoids as well as the molecular mechanisms underlying this effectiveness.

Protective effect of moringa seed extract on kidney damage in rats fed a high-fat and high-fructose diet

Objective

Moringa is a common plant that contains high levels of antioxidants. In this study, we aimed to analyze the protective effect of moringa seed extract on the kidneys of a rat model maintained on a high-fat and high-fructose (HFHF) diet.

Methods

An experiment with a pretest-posttest control group design was used to measure metabolic parameters and determine kidney function, while a posttest-only method was used for the control group to determine glomerular volume and superoxide dismutase (SOD) expression. Purposive sampling was used on 28 rats divided into four groups: a control (K1) group, and three groups fed a HFHF diet for 53 days (K2, K3, and K4). Subsequently, K3 and K4 were given 150 and 200 mg/kg BW per day moringa seed extract for 28 days. Data were analyzed using IBM® SPSS® Statistics version 22 software.

Results

Analysis showed that the diet increased the risk of metabolic syndrome, as evidenced by weight gain, glucose, and triglycerides. The optimal dose of moringa seed extract significantly improved glomerular volume (p = 0.001). The expression of SOD in kidney tubules and glomeruli was significantly different with each group (p = 0.002 and p = 0.001) respectively.

Conclusion

The administration of moringa seed extract provided a protective effect on the kidney by reducing serum creatinine levels, improving overall structure, and increasing the expression of SOD, a key antioxidant.

Antimicrobial, Antidiabetic, Antioxidant, and Anticoagulant Activities of Cupressus sempervirens In Vitro and In Silico

In the last decade, the urgent need to explore medicinal plants or drug development has increased enormously around the world to overcome numerous health problems. In the present investigation, HPLC indicated the existence of 18 phenolic and flavonoid compounds in the Cupressus sempervirens extract. Hesperetin represents the greatest concentration (25,579.57 µg/mL), while other compounds, such as pyro catechol, rutin, gallic acid, chlorogenic acid, naringenin, and quercetin, were recognized in concentrations of 2922.53 µg/mL, 1313.26 µg/mL, 1107.26 µg/mL, 389.09 µg/mL, 156.53 µg/mL, and 97.56 µg/mL, respectively. The well diffusion method documented the antibacterial/antifungal activity of C. sempervirens extract against E. faecalis, E. coli, C. albicans, S. typhi, S.aureus, and M. circinelloid with 35, 33, 32, 25, 23, and 21 mm inhibition zones, respectively, more than the standard antibiotic/antifungal agent. Low values ranging from 7.80 to 15.62 µg/mL of MIC and MBC were recorded for E. faecalis, E. coli, and C. albicans. From the 1- diphenyl-2-picryl hydrazyl (DPPH) assay, promising antioxidant activity was recorded for C. sempervirens extract with IC50 of an 8.97 µg/mL. Moreover, ferric reducing antioxidant power (FRAP) and total antioxidant capacity assays (TAC) confirmed the antioxidant activity of the extract, which was expressed as the ascorbic acid equivalent (AAE) of 366.9 ± 0.2 µg/mg and 102 ± 0.2 µg/mg of extracts, respectively. α-amylase and α-glucosidase inhibition % were determined to express the antidiabetic activity of the extract in vitro, with promising IC50 value (27.01 µg/mL) for α-amylase compared to that of acarbose (50.93 µg/mL), while IC50 value of the extract for α-glucosidase was 19.21µg/mL compared to that of acarbose 4.13 µg/mL. Prothrombin time (PT) and activated partial thromboplastin time (APTT) revealed the role of C. sempervirens extract as an anticoagulant agent if compared with the activity of heparin. Binding interactions of hesperetin and gallic acid were examined via the Molecular Operating Environment (MOE) Dock software against E. faecalis (PDB ID: 3CLQ), C. albicans (PDB ID: 7RJC), α-amylase (PDB ID: 4W93), and α-glucosidase (PDB ID: 3TOP). The obtained results shed light on how molecular modeling methods might inhibit the tested compounds, which have the potential to be useful in the treatment of target proteins.

Potential Benefits of Antioxidant Phytochemicals in Type 2 Diabetes

The clinical relationship between diabetes and inflammation is well established. Evidence clearly indicates that disrupting oxidant-antioxidant equilibrium and elevated lipid peroxidation could be a potential mechanism for chronic kidney disease associated with type 2 diabetes mellitus (T2DM). Under diabetic conditions, hyperglycemia, especially inflammation, and increased reactive oxygen species generation are bidirectionally associated. Inflammation, oxidative stress, and tissue damage are believed to play a role in the development of diabetes. Although the exact mechanism underlying oxidative stress and its impact on diabetes progression remains uncertain, the hyperglycemia-inflammation-oxidative stress interaction clearly plays a significant role in the onset and progression of vascular disease, kidney disease, hepatic injury, and pancreas damage and, therefore, holds promise as a therapeutic target. Evidence strongly indicates that the use of multiple antidiabetic medications fails to achieve the normal range for glycated hemoglobin targets, signifying treatment-resistant diabetes. Antioxidants with polyphenols are considered useful as adjuvant therapy for their potential anti-inflammatory effect and antioxidant activity. We aimed to analyze the current major points reported in preclinical, in vivo, and clinical studies of antioxidants in the prevention or treatment of inflammation in T2DM. Then, we will share our speculative vision for future diabetes clinical trials.

A Comprehensive Review of Phytonutrients as a Dietary Therapy for Obesity

Obesity is a complex medical condition mainly caused by eating habits, genetics, lifestyle, and medicine. The present study deals with traditional diets like the Mediterranean diet, Nordic diet, African Heritage diet, Asian diet, and DASH, as these are considered to be sustainable diets for curing obesity. However, the bioavailability of phytonutrients consumed in the diet may vary, depending on several factors such as digestion and absorption of phytonutrients, interaction with other substances, cooking processes, and individual differences. Hence, several phytochemicals, like polyphenols, alkaloids, saponins, terpenoids, etc., have been investigated to assess their efficiencies and safety in the prevention and treatment of obesity. These phytochemicals have anti-obesity effects, mediated via modulation of many pathways, such as decreased lipogenesis, lipid absorption, accelerated lipolysis, energy intake, expenditure, and preadipocyte differentiation and proliferation. Owing to these anti-obesity effects, new food formulations incorporating these phytonutrients were introduced that can be beneficial in reducing the prevalence of obesity and promoting public health.

Cumulative effects of exercise training and consumption of propolis on managing diabetic dyslipidemia in adult women: a single-blind, randomized, controlled trial with pre-post-intervention assessments

Dyslipidemia is an imbalance of various lipids, and propolis, as a natural resinous viscos mixture made by Apis mellifera L. could improve in this condition. In this single-blind, randomized trial, 60 women with type 2 diabetes and dyslipidemia were divided into four groups: (1) the patients who did not apply the combined training and 500 mg propolis capsules supplement (Control group); (2) subjects performed combined training, including aerobic and resistance training (EXR); (3) subjects received the 500 mg propolis supplement capsules (SUPP); (4) Subjects performed combined training along with receiving the 500 mg propolis supplement capsules (EXR + SUPP). We evaluated the concentration of CTRP12, SFRP5, interleukin-6 (IL6), superoxide dismutase (SOD), malondialdehyde (MDA), adiponectin, and total antioxidant capacity (TAC) before and after the intervention. MDA, TAC, IL6, CTRP12, SFRP5 IL6, adiponectin, and lipid profile levels ameliorated in the EXR + SUPP group. We found that 8 weeks of treatment by combined exercise training and propolis supplement decreased inflammation activity and increased antioxidant defense in women with diabetic dyslipidemia.Trial registration This study was registered in the Iranian Registry of Clinical Trials; IRCT code: IRCT20211229053561N1.

Paliurus spina-christi Mill fruit extracts improve glucose uptake and activate the insulin signaling pathways in HepG2 insulin-resistant cells

BACKGROUND

Paliurus spina-christi Mill. (PSC) fruit is frequently used in the treatment of diabetes mellitus in Mediterranean regions. Here, we investigated the effects of various PSC fruit extracts (PSC-FEs) on glucose consumption and some key mediators of insulin signaling pathways in high glucose and high insulin-induced insulin-resistant HepG2 cells.

METHODS

The effects of methanolic, chloroform and total extracts on cell proliferation were assessed by the MTT assay. The potential of non-toxic extracts on glucose utilization in insulin-resistant HepG2 cells was checked using a glucose oxidase assay. AKT and AMP-activated protein kinase (AMPK) pathway activation and mRNA expression levels of insulin receptor (INSR), glucose transporter 1 (GLUT1), and glucose transporters 4 (GLUT4) were determined by western blotting and real-time PCR, respectively.

RESULTS

We found that high concentrations of methanolic and both low and high concentrations of total extracts were able to enhance glucose uptake in an insulin-resistant cell line model. Moreover, AKT and AMPK phosphorylation were significantly increased by the high strength of methanolic extract, while total extract raised AMPK activation at low and high concentrations. Also, GLUT 1, GLUT 4, and INSR were elevated by both methanolic and total extracts.

CONCLUSIONS

Ultimately, our results shed new light on methanolic and total PSC-FEs as sources of potential anti-diabetic medications, restoring glucose consumption and uptake in insulin-resistant HepG2 cells. These could be at least in part due to re-activating AKT and AMPK signaling pathways and also increased expression of INSR, GLUT1, and GLUT4. Overall, active constituents present in methanolic and total extracts of PCS are appropriate anti-diabetic agents and explain the use of these PSC fruits in traditional medicine for the treatment of diabetes.

Regulatory mechanisms of kaempferol on iNOS expression in RINm5F β-cells under exposure to interleukin-1β

Proinflammatory cytokines and NO play crucial roles in islet β-cells dysfunction. Though anti-inflammatory effects of kaempferol were revealed in several studies, the detailed mechanisms remain unclear. This study explored protective actions of kaempferol in interleukin-1β-treated RINm5F β-cells. Kaempferol significantly inhibited NO generation, iNOS protein, and iNOS mRNA level. Promoter study, EMSA, and κB-dependent reporter assay showed that kaempferol inhibited NF-κB-mediated iNOS gene transcription. Also, we found that kaempferol accelerated iNOS mRNA instability in iNOS 3'-UTR construct and actinomycin D chase studies. Additionally, kaempferol reduced iNOS protein stability in cycloheximide chase study and it inhibited NOS enzyme activity. Kaempferol inhibited ROS generation and preserved cell viability, and it improved insulin release. These findings suggest that kaempferol appears to be helpful in protecting islet β-cells, thereby supports kaempferol as a supplementary therapeutic candidate in inhibiting the incidence and progression of diabetes mellitus.

Honey polyphenols: regulators of human microbiota and health

A comprehensive review of research over the last decade was conducted to carry out this work. The main objective of this work is to present relevant evidence of the effect of honey intake on the human intestinal microbiota and its relationship with the improvement of various chronic diseases, such as cirrhosis, metabolic syndrome, diabetes, and obesity, among others. Therefore, this work focuses on the health-improving honey dietary supplementation implications associated with specific changes in the human microbiota and their biochemical mechanisms to enhance the proliferation of beneficial microorganisms and the inhibition of pathogenic microorganisms. Consumption of honey polyphenols significantly improves people's health conditions, especially in patients with chronic disease. Hence, honey intake unequivocally constitutes an alternative way to enhance health and could be used to prevent some relevant chronic diseases.

Development and formulation of antidiabetic property of Anarcadium occidantale-based solid lipid microparticles

Anacardium occidentale (AO) possesses potent anti-diabetic properties, owing to its high phytochemicals content. This study attempted to maximise the efficacy of AO by encapsulating it in a solid lipid microparticle (SLMs) formulation. Leaves of AO were extracted with water and formulated into SLMs using a lipid matrix composed of P90H and Dika fat. Characterisation of the SLMs include morphology, particle size, pH, encapsulation efficiency percentage, in vitro release and anti-diabetic properties. SLMs were spherical with sizes ranging from 16.7 ± 0.8 µm to 40.12 ± 2.34 µm and had a fairly stable pH over time. Highest drug entrapment was 87%_. Batch A₂ exhibited an even release of 89%, sustained over time, and a mean percentage reduction in glucose of 25.9% at 12 h after oral administration to study animals. Anacardium occidentale-loaded SLMs exhibited a good hypoglycaemic effect and can be used in the management of diabetes.

Effect of maternal true combined endodontic-periodontal lesion on insulin and inflammatory pathway in adult offspring

BACKGROUND

Maternal periodontal disease (PED) and apical periodontitis (AP) are associated insulin resistance (IR), increased tumor necrosis factor-α (TNF-α) levels, and alterations in insulin signaling (IS) in the gastrocnemius muscle (GM) of adult offspring. TNF-α stimulates I kappa B kinase (IKK) and c-Jun N-terminal protein kinase (JNK), resulting in IS attenuation. However, studies that investigated the maternal true endodontic-periodontal lesion (EPL) in offspring are scarce, and in this case, the impact could be even higher. This study aimed to evaluate the effects of EPL on the IR, IS, and inflammatory pathways on the offspring GM.

METHODS

Female Wistar rats were distributed into control, AP, PED, and EPL groups. After 30 days of oral inflammation induction, rats from all groups were allowed to mate with healthy rats. The bodyweight of the offspring was assessed from birth to 75 days of age. After 75 days, the following measurements were performed: glycemia, insulinemia, IR, TNF-α content, and IKKα/β, JNK, pp185 (Tyr), and IRS-1 (Ser) phosphorylation status in the GM.

RESULTS

Maternal PED and EPL were associated with low birth weights. All maternal oral inflammations promoted IR and IS impairment in the GM and only maternal PED and EPL caused an increase in TNF-α content and IKKα/β phosphorylation status in the GM of offspring. The EPL-o group showed worsening of metabolic changes when compared to offspring of rats with AP or PED.

CONCLUSION

Association of maternal AP and PED promoted a more pronounced worsening in the health of the adult offspring. This article is protected by copyright. All rights reserved.

Drug Discovery of Plausible Lead Natural Compounds That Target the Insulin Signaling Pathway: Bioinformatics Approaches

The growing smooth talk in the field of natural compounds is due to the ancient and current interest in herbal medicine and their potentially positive effects on health. Dozens of antidiabetic natural compounds were reported and tested in vivo, in silico, and in vitro. The role of these natural compounds, their actions on the insulin signaling pathway, and the stimulation of the glucose transporter-4 (GLUT4) insulin-responsive translocation to the plasma membrane (PM) are all crucial in the treatment of diabetes and insulin resistance. In this review, we collected and summarized a group of available in vivo and in vitro studies which targeted isolated phytochemicals with possible antidiabetic activity. Moreover, the in silico docking of natural compounds with some of the insulin signaling cascade key proteins is also summarized based on the current literature. In this review, hundreds of recent studies on pure natural compounds that alleviate type II diabetes mellitus (type II DM) were revised. We focused on natural compounds that could potentially regulate blood glucose and stimulate GLUT4 translocation through the phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt) pathway. On attempt to point out potential new natural antidiabetic compounds, this review also focuses on natural ingredients that were shown to interact with proteins in the insulin signaling pathway in silico, regardless of their in vitro/in vivo antidiabetic activity. We invite interested researchers to test these compounds as potential novel type II DM drugs and explore their therapeutic mechanisms.

Virtual screening and in vitro experimental verification of LuxS inhibitors from natural products for Lactobacillus reuteri

The rapid proliferation and colonization of probiotics in the intestines are essential for human health. Quorum sensing (QS) is a communication mechanism among bacteria, which can regulate various bacterial crowd behavior. This study aimed to enhance the viability of Lactobacillus reuteri 1-12 by regulating QS. Herein, we built a database containing 72 natural products (previously reported) that can improve intestinal flora. Virtual screening (VS) was subsequently conducted to screen four potential active compounds. After that, molecular docking was conducted to analyze the binding mode of the four natural products to S-Ribosylhomocysteinase (LuxS). The results showed that norathyriol, mangiferin, baicalein, and kaempferol had good binding ability to LuxS. The validation experiment showed that norathyriol, mangiferin, baicalein, and kaempferol could inhibit the production of autoinducer-2 (AI-2). Moreover, mangiferin significantly increased L. reuteri 1-12 biomass and promoted L. reuteri 1-12 biofilm formation and structure. Besides, only mangiferin inhibited luxS expression, thus increasing L. reuteri 1-12 biomass. This research indicated that mangiferin may be a potential inhibitor of LuxS, promoting the probiotic properties of L. reuteri and human health.

Isolation, Identification and Pharmacological Effects of Mandragora autumnalis Fruit Flavonoids Fraction

Since ancient times, Mandragora autumnalis has been used as a traditional medicinal plant for the treatment of numerous ailments. In light of this, the current study was designed to isolate and identify the chemical constituents of the flavonoids fraction from M. autumnalis ripe fruit (FFM), and evaluate its DPPH scavenging, anti-lipase, cytotoxicity, antimicrobial and antidiabetic effects. An ethyl acetate extract of M. autumnalis was subjected to a sequence of silica gel column chromatography using different eluents with various polarities. The chemical structures of the isolated compounds were identified using different spectral techniques, including ¹H NMR and ¹³C NMR. FFM's anti-diabetic activity was assessed using a glucose transporter-4 (GLUT4) translocation assay, as well as an inhibition against α-amylase and α-glucosidase using standard biochemical assays. The FFM anti-lipase effect against porcine pancreatic lipase was also evaluated. Moreover, FFM free radical scavenging activity using the DPPH test and antimicrobial properties against eight microbial strains using the micro-dilution method were also assessed. Four flavonoid aglycones were separated from FFM and their chemical structures were identified. The structures of the isolated compounds were established as kaempferol 1, luteolin 2, myricetin 3 and (+)-taxifolin 4, based on NMR spectroscopic analyses. The cytotoxicity test results showed high cell viability (at least 90%) for up to 1 mg/mL concentration of FFM, which is considered to be safe. A dose-dependent increase in GLUT4 translocation was significantly shown (p < 0.05) when the muscle cells were treated with FFM up to 0.5 mg/mL. Moreover, FFM revealed potent α-amylase, α-glucosidase, DPPH scavenging and porcine pancreatic lipase inhibitory activities compared with the positive controls, with IC₅₀ values of 72.44 ± 0.89, 39.81 ± 0.74, 5.37 ± 0.41 and 39.81 ± 1.23 µg/mL, respectively. In addition, FFM inhibited the growth of all of the tested bacterial and fungal strains and showed the greatest antibacterial activity against the K. pneumoniae strain with a MIC value of 0.135 µg/mL. The four flavonoid molecules that constitute the FFM have been shown to have medicinal promise. Further in vivo testing and formulation design are needed to corroborate these findings, which are integral to the pharmaceutical and food supplement industries.

Hypoglycemic Effects of Plant Flavonoids: A Review

Diabetes mellitus is a metabolic disorder with chronic high blood glucose levels, and it is associated with defects in insulin secretion, insulin resistance, or both. It is also a major public issue, affecting the world's population. This disease contributes to long-term health complications such as dysfunction and failure of multiple organs, including nerves, heart, blood vessels, kidneys, and eyes. Flavonoids are phenolic compounds found in nature and usually present as secondary metabolites in plants, vegetables, and fungi. Flavonoids possess many health benefits such as anti-inflammatory and antioxidant activities, and naturally occurring flavonoids contribute to antidiabetic effects.Many studies conducted in vivo and in vitro have proven the hypoglycemic effect of plant flavonoids. A large number of studies showed that flavonoids hold positive results in controlling the blood glucose level in streptozotocin (STZ)-induced diabetic rats and further prevent the complications of diabetes. The future development of flavonoid-based drugs is believed to provide significant effects on diabetes mellitus and diabetes complication diseases. This review aims at summarizing the various types of flavonoids that function as hyperglycemia regulators such as inhibitors of α-glucosidase and glucose cotransporters in the body. This review article discusses the hypoglycemic effects of selected plant flavonoids namely quercetin, kaempferol, rutin, naringenin, fisetin, and morin. Four search engines, PubMed, Google Scholar, Scopus, and SciFinder, are used to collect the data.

UPLC/ESI-MS Phytochemical Screening of Deverra tortuosa Haematological and Histopathological Studies and Streptozotocin-Induced Diabetes in Rat

Herbal plants represent a new source of hypoglycemic antidiabetic drugs; haematological and histopathological studies of methanol extract of Deverra tortuosa in streptozotocin-induced diabetic rats were investigated in vivo. A single intraperitoneal injection of 160 mg/kg bodyweights of streptozotocin was used to cause diabetes. Blood glucose levels were tested with an AccuCheck Advantage II glucometer and blood glucose test strips. After diabetes was confirmed, animals were orally treated with the extract, metformin, and insulin according to the experimental design. After extract therapy, histological alterations in the pancreas of diabetic rats were investigated. When compared to a control group, daily oral administration of D. tortuosa extract (300 mg/kg body weight) plus metformin (100 mg/kg) had a positive effect on blood glucose levels as well as showed an increased number of white blood cells (WBCs) and red blood cells (RBCs). The treatment with the extract for two weeks showed a positive impact on pancreatic histopathological changes in the groups with the diabetic rats. Phenolic fraction of the methanol extract was screened by the liquid chromatography-mass spectroscopy (LC-MS) method, which unveiled the existence of flavonoid compounds and phenolics as kaempferol, rutin, isorhamnetin-3-O-rutinoside, caffeic acid, and 4-hydroxybenzoic acid 4-O-glucoside. The results confirmed the use of the plant as an antidiabetic agent; the research recommended further studies on the plant to use the plant as an antidiabetic drug, where the plant extract also showed improvement in blood parameters.

Natural Antidiabetic Agents: Molecular Docking Study using the Extra Precision Method

Background:

Diabetes mellitus (DM) is the most severe, chronic metabolic disorder with abnormally elevated concentration of plasma glucose levels, leading to significant complications, such as diabetic neuropathy, retinopathy, and cardiovascular illnesses.

Objective:

Synthetic drugs have some disadvantages and limitations. Therefore, there is a continuous global and insisting need for new and better treatment options for Diabetes Mellitus.

Methods:

In this study, 42 natural anti-diabetic constituents like alkaloids, glycosides, and flavonoids were selected on the basis of mechanism of action on various molecular targets such as Glucokinase activator, Dipeptidyl peptidase 4 (DPP-4), peroxisome proliferator-activated receptors (PPARγ), and α-glucosidase inhibitor. To investigate the potential molecular targets for natural antidiabetcs agents, molecular docking study was carried out using the Glide module of Schrodinger Suit.

Results:

Interactions of specific amino acid of the targets with the atoms of the chemical constituents and their Gscore indicate the proper binding of chemical constituents with target. The results revealed that Myricetin, Quercetin ae interacts with active sites of the target chosen and can be used for the designing of novel compounds as anti-dibetics.

Conclusion:

Calculated GScore could be used as a preliminary tool for screening of anti-diabetic drugs before performing experimental activity.

Kaempferol attenuates diabetic nephropathy in streptozotocin-induced diabetic rats by a hypoglycaemic effect and concomitant activation of the Nrf-2/Ho-1/antioxidants axis

This study examined the protective effect of Kaempferol against streptozotocin-induced diabetic nephropathy (DN) in rats and studies the underlying mechanisms. Rats were divided into 4 groups as control, control + Kaempferol, STZ, and STZ + Kaempferol. All treatments were conducted for 8 weeks daily after the induction of diabetes. Kaempferol prevented STZ-induced weight and food loss and attenuated renal damage and the alterations in all biochemical related parameters. Concomitantly, Kaempferol reduced renal levels of TNF-α and IL-6, cleaved caspase-3, p38, and Bax, suppressing JNK phosphorylation and NF-κB p65 transactivation, and upregulation of Bcl-2. In both control and STZ-diabetic rats, Kaempferol reduced fasting glucose levels, increased fasting insulin levels and HOMA-β, reduced the levels of ROS and MDA, stimulated SOD and GSH levels, and increased the expression of Nrf2 and HO-1. In conclusion, Kaempferol prevents STZ-induced diabetic nephropathy, mainly, by antioxidant potential, mediated by the upregulation of the Nrf-2/HO-1 axis.

Natural Compound α-PGG and Its Synthetic Derivative 6Cl-TGQ Alter Insulin Secretion: Evidence for Diminishing Glucose Uptake as a Mechanism

PURPOSE

Previously we showed that natural compound α-penta-galloyl-glucose (α-PGG) and its synthetic derivative 6-chloro-6-deoxy-1,2,3,4-tetra-O-galloyl-α-D-glucopyranose (6Cl-TGQ) act to improve insulin signaling in adipocytes by increasing glucose transport. In this study, we investigated the mechanism of actions of α-PGG and 6Cl-TGQ on insulin secretion.

METHODS

Mouse islets and/or INS-1832/13 beta-cells were used to test the effects of our compounds on glucose-stimulated insulin secretion (GSIS), intracellular calcium [Ca²⁺]_i using fura-2AM, glucose transport activity via a radioactive glucose uptake assay, intracellular ATP/ADP, and extracellular acidification (ECAR) and mitochondrial oxygen consumption rates (OCAR) using Seahorse metabolic analysis.

RESULTS

Both compounds reduced GSIS in beta-cells without negatively affecting cell viability. The compounds primarily diminished glucose uptake into islets and beta-cells. Despite insulin-like effects in the peripheral tissues, these compounds do not act through the insulin receptor in islets. Further interrogation of the stimulus-secretion pathway showed that all the key metabolic factors involved in GSIS including ECAR, OCAR, ATP/ADP ratios, and [Ca²⁺]_i of INS-1832/13 cells were diminished after the compound treatment.

CONCLUSION

The compounds suppress glucose uptake of the beta-cells, which consequently slows down the rates of glycolysis and ATP synthesis, leading to decrease in [Ca²⁺]_i and GSIS. The difference between adipocytes and beta-cells in effects on glucose uptake is of great interest. Further structural and functional modifications could produce new compounds with optimized therapeutic potentials for different target cells. The higher potency of synthetic 6Cl-TGQ in enhancing insulin signaling in adipocytes but lower potency in reducing glucose uptake in beta-cells compared to α-PGG suggests the feasibility of such an approach.

Nutritional Composition and Bioactive Compounds in Tomatoes and Their Impact on Human Health and Disease: A Review

Tomatoes are consumed worldwide as fresh vegetables because of their high contents of essential nutrients and antioxidant-rich phytochemicals. Tomatoes contain minerals, vitamins, proteins, essential amino acids (leucine, threonine, valine, histidine, lysine, arginine), monounsaturated fatty acids (linoleic and linolenic acids), carotenoids (lycopene and β-carotenoids) and phytosterols (β-sitosterol, campesterol and stigmasterol). Lycopene is the main dietary carotenoid in tomato and tomato-based food products and lycopene consumption by humans has been reported to protect against cancer, cardiovascular diseases, cognitive function and osteoporosis. Among the phenolic compounds present in tomato, quercetin, kaempferol, naringenin, caffeic acid and lutein are the most common. Many of these compounds have antioxidant activities and are effective in protecting the human body against various oxidative stress-related diseases. Dietary tomatoes increase the body's level of antioxidants, trapping reactive oxygen species and reducing oxidative damage to important biomolecules such as membrane lipids, enzymatic proteins and DNA, thereby ameliorating oxidative stress. We reviewed the nutritional and phytochemical compositions of tomatoes. In addition, the impacts of the constituents on human health, particularly in ameliorating some degenerative diseases, are also discussed.

Amelioration of Olanzapine-Induced Impaired Glucose Tolerance in Mice with Methanol Extract of Steamed Brassica Oleracea (Cabbage) Leaves

Olanzapine is an antipsychotic drug and has been reported to induce impaired glucose tolerance leading to high blood glucose levels. In oral glucose tolerance tests (OGTT), methanolic extract of steamed cabbage (Brassica oleracea L. var. capitata) (MEBO) leaves have been shown to reduce elevated blood glucose levels in glucose-loaded mice. It was thus of interest to determine whether MEBO leaves can ameliorate olanzapineinduced impaired glucose tolerance in mice, which have been administered olanzapine for 28 days. Impaired glucose tolerance was measured through OGTT in mice. Olanzapine (28 days)-administered mice showed elevated blood glucose in OGTT. MEBO leaves showed significant reduction of blood glucose level in OGTT in mice (compared to vehicle or olanzapine treated mice for 28 days, Groups 2 and 3, respectively) both when administered for 28 days along with olanzapine, as well when administered 60 min prior to glucose loading in OGTT (positive control glibenclamide administered at 10 mg/kg). A single dose of MEBO (400 mg/kg) was used based on previous studies. Thus, MEBO leaves can be beneficial for improving glucose tolerance and reduce blood glucose levels in olanzapine-induced elevated blood glucose levels.

Kaempferol Promotes Glucose Uptake in Myotubes through a JAK2-Dependent Pathway

Kaempferol possesses various health-promoting functions including antihyperglycemic activity, but its underlying molecular mechanism is poorly understood. Glucose transporter 4 (GLUT4) plays an important role in the uptake of blood glucose into muscle cells after its translocation to the plasma membrane. In this study, we demonstrated that kaempferol at 1.0 nM or more significantly increased the uptake of 2-[³H]- deoxy-d-glucose by 1.3-1.4-fold in L6 myotubes. Kaempferol at 10 pM or more also significantly increased GLUT4 translocation by 1.3-1.6-fold. Kaempferol at 1.0 nM significantly increased the phosphorylation of adenosine monophosphate-activated protein kinase (AMPK) by 2.9-fold, liver kinase B1 and Janus kinase 2 (JAK2) by 1.9-fold, and signal transducer and activator of transcription 3 by 3.7-fold. In addition, kaempferol increased phosphorylation of phosphoinositide 3-kinase (PI3K) by 1.8-fold but not the insulin receptor. Small interfering RNA (siRNA) for AMPK, JAK2, or PI3K canceled kaempferol-induced glucose uptake and GLUT4 translocation. Furthermore, siRNA for JAK2 canceled kaempferol-induced phosphorylation of AMPK and PI3K. These results indicate that a JAK2-depdendent pathway regulates kaempferol-induced glucose uptake and GLUT4 translocation in L6 myotubes and that kaempferol may be an effective compound for the prevention of hyperglycemia.

A Review on Oxidative Stress, Diabetic Complications, and the Roles of Honey Polyphenols

Despite the availability of various antidiabetic drugs, diabetes mellitus (DM) remains one of the world's most prevalent chronic diseases and is a global burden. Hyperglycaemia, a characteristic of type 2 diabetes mellitus (T2DM), substantially leads to the generation of reactive oxygen species (ROS), triggering oxidative stress as well as numerous cellular and molecular modifications such as mitochondrial dysfunction affecting normal physiological functions in the body. In mitochondrial-mediated processes, oxidative pathways play an important role, although the responsible molecular mechanisms remain unclear. The impaired mitochondrial function is evidenced by insulin insensitivity in various cell types. In addition, the roles of master antioxidant pathway nuclear factor erythroid 2-related factor 2 (Nrf2)/Kelch-like ECH-associated protein 1 (Keap1)/antioxidant response elements (ARE) are being deciphered to explain various molecular pathways involved in diabetes. Dietary factors are known to influence diabetes, and many natural dietary factors have been studied to improve diabetes. Honey is primarily rich in carbohydrates and is also abundant in flavonoids and phenolic acids; thus, it is a promising therapeutic antioxidant for various disorders. Various research has indicated that honey has strong wound-healing properties and has antibacterial, anti-inflammatory, antifungal, and antiviral effects; thus, it is a promising antidiabetic agent. The potential antidiabetic mechanisms of honey were proposed based on its major constituents. This review focuses on the various prospects of using honey as an antidiabetic agent and the potential insights.

Constitution of a comprehensive phytochemical profile and network pharmacology based investigation to decipher molecular mechanisms of Teucrium polium L. in the treatment of type 2 diabetes mellitus

Background

Type 2 diabetes mellitus (T2DM) is a metabolic disease affecting a huge population worldwide. Teucrium polium L. has been used as a folk medicine for the treatment of T2DM in Anatolia, Turkey. The antihyperglycemic effect of the plant was reported previously. However, there was no detailed study on the underlying molecular mechanisms. In this study, we generated a research plan to clarify the active constituents of the extract and uncover the molecular mechanisms using network pharmacology analysis.

Methods

For this purpose, we composed a dataset of 126 compounds for the phytochemical profile of the aerial parts of T. polium. Drug-likeness of the compounds was evaluated, and 52 compounds were selected for further investigation. A total of 252 T2DM related targets hit by selected compounds were subjected to DAVID database.

Results

The KEGG pathway analysis showed enrichment for the TNF signaling pathway, insulin resistance, the HIF-1 signaling pathway, apoptosis, the PI3K-AKT signaling pathway, the FOXO signaling pathway, the insulin signaling pathway, and type 2 diabetes mellitus which are related to T2DM . AKT1, IL6, STAT3, TP53, INS, and VEGFA were found to be key targets in protein-protein interaction. Besides these key targets, with this study the role of GSK3β, GLUT4, and PDX1 were also discussed through literature and considered as important targets in the antidiabetic effect of T. polium. Various compounds of T. polium were shown to interact with the key targets activating PI3K-AKT and insulin signaling pathways.

Conclusions

According to these findings, mainly phenolic compounds were identified as the active components and IRS1/PI3K/AKT signaling and insulin resistance were identified as the main pathways regulated by T. polium. This study reveals the relationship of the compounds in T. polium with the targets of T2DM in human. Our findings suggested the use of T. polium as an effective herbal drug in the treatment of T2DM and provides new insights for further research on the antidiabetic effect of T. polium.

Protective and therapeutic effects of natural products against diabetes mellitus via regenerating pancreatic β-cells and restoring their dysfunction

Diabetes mellitus is a growing public health concern and an increasing interest has been raised to search for new compounds with therapeutic effects on β-cells. There are chronic insulin resistance and loss of β-cell mass in the case of type-2 diabetes which covers about 90% of total diabetic patients. This work aims to critically review the protective and regenerative effects of various antidiabetic natural products on pancreatic β-cells. A thorough literature survey was conducted on the natural molecules and extracts having a protective, regenerative, and repairing effect on β-cells. The primary source of the literature was online scientific databases such as PubMed, Scopus, and Google Scholar. Besides, selected relevant textbooks were also consulted. Various natural molecules including berberine, curcumin, mangiferin, stevioside and capsaicin, and extracts obtained from the plants like Capsicum annum, Gymnema sylvestre, Stevia rebaudiana and Nymphaea stellate, were found to produce regenerative and anti-apoptosis effects on β-cells. These natural products were also found to increase insulin secretion by stimulating β-cells. The present review concluded that a large number of molecules and extracts, abundantly found in nature, possess antidiabetic effect via targeting β-cells. Further research is warranted to use these agents as a drug against diabetes.

Allium Flavonols: Health Benefits, Molecular Targets, and Bioavailability

Allium species are revered worldwide as vegetables, condiments, and spices as well as the therapeutic agents in traditional medicine. The bioactive compounds in alliums mainly include organosulfur compounds, polyphenols, dietary fibers, and saponins. Flavonoids, particularly flavonols from alliums, have been demonstrated to have the antioxidant, anticancer, hypolipidemic, anti-diabetic, cardioprotective, neuroprotective, and antimicrobial activities. However, flavonols are mostly characterized from onions and have not been comprehensively reviewed across different species. This article therefore focuses on flavonol profiles from different Allium species, their health effects, underlying molecular mechanisms, and bioavailability. Intriguingly, the functional health effects of flavonols were mainly ascribed to their antioxidant and anti-inflammatory activities involving a cascade of multiple signaling pathways. Although the Allium-derived flavonols offer tremendous potential in preventing chronic disease risks, in-depth studies are needed to translate their clinical application.

Dual Anti-/Prooxidant Behaviors of Flavonoids Pertaining to Cu(II)-Catalyzed Tyrosine Nitration of the Insulin Receptor Kinase Domain in an Antidiabetic Study

Flavonoid, as a potent antioxidant, exerts many beneficial effects in type 2 diabetes, whereas the prooxidative property may be also important in vivo if copper is involved. Here, we chose an insulin receptor kinase domain fragment (KK-1, residues 1126-1165), containing the A-loop of the receptor as well as three key autophosphorylation sites (Tyr¹¹⁵⁸, Tyr¹¹⁶², and Tyr¹¹⁶³) associated with receptor signal transduction to investigate the roles and the structure-activity relationship of three antidiabetic flavonoids (kaempferol, luteolin, and apigenin) and two others with a similar structure (diosmetin and genistein), on modulation of Cu(II)-mediated tyrosine nitration and the corresponding effect on its functional phosphorylation in the Cu²⁺/H₂O₂/NO₂^- system. We found that both properties of flavonoid played roles on inhibition of Cu(II)-mediated protein nitration in the H₂O₂/NO₂^- system: (1) on the one hand, flavonoid scavenged free radicals as antioxidants, inhibited tyrosine nitration, and thus inhibited the reduction of tyrosine phosphorylation caused by tyrosine nitration; and (2) on the other hand, flavonoid promoted ^•OH production as a prooxidant, which increased 3,3'-dityrosine formation. The formation of 3,3'-dityrosine decreased Cu²⁺-induced tyrosine nitration and thus interfered with its phosphorylation. This study confirms that the weight relationship between antioxidation and prooxidation of a flavonoid needs to be studied clearly before nutritional and medical applications.

Network Pharmacology-Based Exploration of Synergistic Mechanism of Guanxin II Formula (II) for Coronary Heart Disease

OBJECTIVE

To study the pharmacological mechanism of Guanxin II formula (II) for treatment of coronary heart disease (CHD).

METHODS

A network pharmacology-based method was utilized. First candidate compounds, targets of GX II were collected using PharmMapper, BATMAN-TCM, DrugBank and SwissTargetPrediction, and targets on CHD were mined from GeneCards, DisGenet, DrugBank and GEO. Afterwards, the big hub compounds and targets were chosen in the candidate compounds-direct therapeutic targets on the CHD (C-T) network and the direct therapeutic targets on the CHD (T-D) network. Furthermore, the Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analysis were performed to identify the enriched terms. Finally, a molecular docking simulation strategy was adopted to verify the binding capacity between the big hub compounds and big hub targets on CHD.

RESULTS

First, 114 candidate compounds were selected with the following criteria: OB⩾30%, DL⩾0.18, and HL ⩾4 h. Then, 1,035 targets of GX II were gathered, while 928 targets on CHD were collected. Afterwards, 196 common targets of compound targets and therapeutic targets on CHD were defined as direct therapeutic targets acting on CHD. In addition, the contribution index (CI) in the C-T network was calculated, and 4 centrality properties, including degree, betweenness, closeness and coreness, in the T-D network, 4 big hub compounds, and 6 big hub targets were eventually chosen. Furthermore, the GO and KEGG analysis indicated that GX II acted on CHD by regulating the reactive oxygen species metabolism, steroid metabolism, lipid metabolism, inflammatory response, proliferation, differentiation and apoptosis. The docking results manifested excellent binding capacity between the 4 big hub compounds and 6 big hub targets on CHD.

CONCLUSION

This network pharmacology-based exploration revealed that GX II might prevent and inhibit the primary pathological processes of CHD.

Molecular Mechanism of the Effect of Huanglian Jiedu Decoction on Type 2 Diabetes Mellitus Based on Network Pharmacology and Molecular Docking

BACKGROUND

Huanglian Jiedu Decoction (HLJDD) is a Traditional Chinese Medicine (TCM) formula comprising four herbal medicines. This decoction has long been used in China for clinically treating T2DM. However, the molecular mechanism of HLJDD treat for T2DM is still not fully known. Hence, this study was designed to reveal the synergistic mechanism of HLJDD formula in the treatment of T2DM by using network pharmacology method and molecular docking.

METHODS

Retrieving and screening of active components of different herbs in HLJDD and corresponding T2DM-related target genes across multiple databases. Subsequently, STRING and Cytoscape were applied to analysis and construct PPI network. In addition, cluster and topological analysis were employed for the analysis of PPI networks. Then, the GO and KEGG enrichment analysis were performed by using ClueGO tool. Finally, the differentially expressed analysis was used to verify whether the expression of key target genes in T2DM and non-T2DM samples was statistically significant, and the binding capacity between active components and key targets was validated by molecular docking using AutoDock.

RESULTS

There are 65 active components involved in 197 T2DM-related targets that are identified in HLJDD formula. What is more, 39 key targets (AKT1, IL-6, FOS, VEGFA, CASP3, etc.) and 3 clusters were obtained after topological and cluster analysis. Further, GO and KEGG analysis showed that HLJDD may play an important role in treating T2DM and its complications by synergistically regulating many biological processes and pathways which participated in signaling transduction, inflammatory response, apoptotic process, and vascular processes. Differentially expressed analysis showed that AKT1, IL-6, and FOS were upregulated in T2DM samples and a significant between sample differential expression. These results were validated by molecular docking, which identified 5 high-affinity active components in HLJDD, including quercetin, wogonin, baicalein, kaempferol, and oroxylin A.

CONCLUSION

Our research firstly revealed the basic pharmacological effects and relevant mechanisms of the HLJDD in the treatment of T2DM and its complications. The prediction results might facilitate the development of HLJDD or its active compounds as alternative therapy for T2DM. However, more pharmacological experiments should be performed for verification.

Cyclohexane extract of walnut leaves improves indices of oxidative stress, total homocysteine and lipids profiles in streptozotocin-induced diabetic rats

This study aimed to evaluate the effect of two doses of cyclohexane extract of walnut leaves on total homocysteine, lipids profiles, and indices of oxidative stress including superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT), and malondialdehyde (MDA) in diabetic rats. Diabetes was induced by a single intraperitoneal (IP) injection of streptozotocin (50 mg/kg BW). Twenty-eight male Sprague Dawley rats were randomly divided into four groups, group I: control (received sesame oil as vehicle), group II: diabetic control (received sesame oil), group III and IV: diabetic rats treated by 150 and 250 mg/kg body weight (BW) per day extract of walnut leaves, respectively. All groups were treated for 28 days via oral gavage. Fasting blood glucose (FBG) level and body weight measured before injection, 3 days after injection, and on days 0, 7, 14, 21, and 28 of treatment. At the end the 28th day of the experiment, blood samples collected via heart puncture and the sera were used for estimation of the above-mentioned parameters. The results showed a decrease in FBS, TC, TG, LDL-c, VLDL-c, homocysteine, and MDA level and increase in the level of HDL-c in diabetics treated by walnut leave extracts in a dose-dependent manner after 28 days. The activity of antioxidant enzymes significantly increased in treated groups compared with diabetic control. It can be concluded that cyclohexane extract of walnut leaves has an overall beneficial effect on body weight, fasting blood glucose, lipids profile, antioxidant enzyme activities, and homocysteine.

Retracted: Small Molecule Kaempferol Promotes Insulin Sensitivity and Preserved Pancreatic β-Cell Mass in Middle-Aged Obese Diabetic Mice

[This retracts the article DOI: 10.1155/2015/532984.].

Glucose Tolerance-Improving Activity of Helichrysoside in Mice and Its Structural Requirements for Promoting Glucose and Lipid Metabolism

An acylated flavonol glycoside, helichrysoside, at a dose of 10 mg/kg/day per os for 14 days, improved the glucose tolerance in mice without affecting the food intake, visceral fat weight, liver weight, and other plasma parameters. In this study, using hepatoblastoma-derived HepG2 cells, helichrysoside, trans-tiliroside, and kaempferol 3-O-β-d-glucopyranoside enhanced glucose consumption from the medium, but their aglycones and p-coumaric acid did not show this activity. In addition, several acylated flavonol glycosides were synthesized to clarify the structural requirements for lipid metabolism using HepG2 cells. The results showed that helichrysoside and related analogs significantly inhibited triglyceride (TG) accumulation in these cells. The inhibition by helichrysoside was more potent than that by other acylated flavonol glycosides, related flavonol glycosides, and organic acids. As for the TG metabolism-promoting activity in high glucose-pretreated HepG2 cells, helichrysoside, related analogs, and their aglycones were found to significantly reduce the TG contents in HepG2 cells. However, the desacyl flavonol glycosides and organic acids derived from the acyl groups did not exhibit an inhibitory impact on the TG contents in HepG2 cells. These results suggest that the existence of the acyl moiety at the 6′′ position in the D-glucopyranosyl part is essential for glucose and lipid metabolism-promoting activities.

Dietary plant flavonoids in prevention of obesity and diabetes

Obesity and diabetes are the most prevailing chronic metabolic diseases worldwide from mainly lipid and glucose metabolic dysfunctions and their incidence is increasing at an alarming high rate. Obesity is characterized by excess fat accumulation in WAT and liver and is the central player of insulin resistance in the peripheral tissues from chronic inflammation, lipotoxicity and gut dysbiosis, and plays a key role for development of type 2 diabetes (T2DM) and vascular diseases. Diabetes mellitus, known as diabetes, is chiefly characterized by hyperglycaemia from impaired insulin secretion and insulin resistance. Several identified mutant genes in insulin secretion and resistance and various environmental factors are considered responsible for the onset of this disease. Currently available oral synthetic drugs, biguanides, incretin mimetic, GLP-1R and PPAR agonists and DPP-4 inhibitors for management of obesity and diabetes have several adverse effects in patients on long-term use. Emerging evidence supports the efficacy of dietary plant flavonoids in prevention and attenuation of obesity and diabetes by the protection and proliferation of pancreatic beta-cells and improvement of their insulin secretory function via activation of cAMP/PKA signaling pathway as well as in the improvement of insulin sensitivity in the peripheral metabolic tisssues for glucose uptake and utilization via inhibition of inflammation, lipotoxicity and oxidative stress. These flavonoids improve GLUT-4 expression and translocation to plasma membrane by activation of insulin-sensitive PI3K/Akt signaling and insulin-independent AMPK, SIRT-1 and MOR activation pathways for regulation of glucose homeostasis, and improve fat oxidation and reduce lipid synthesis by regulation of related genes for lipid homeostasis in the body of obese diabetic animals. In this chapter, we have highlighted all these beneficial anti-obesity and antidiabetic potentials of some dietary plant flavonoids along with their molecular actions, bioavailability and pharmacokinetics. In addition, the present understanding and management of obesity and diabetes are also focused.

Kaempferol attenuates imiquimod-induced psoriatic skin inflammation in a mouse model

Psoriasis is an immune-mediated inflammatory skin disease that mainly affects the skin barrier. Treatment for psoriasis mainly includes conventional immunosuppressive drugs. However, long-term treatment with global immunosuppressive agents may cause a variety of side effects, including nephrotoxicity and infections. Kaempferol, a natural flavonol present in various plants, is known to possess potent anti-inflammatory, anti-oxidant and anti-cancerous properties. However, it is unknown whether kaempferol is also anti-psoriatic. Here we established an imiquimod (IMQ)-induced psoriatic mouse model to explore the potential therapeutic effects of kaempferol on psoriatic skin lesions and inflammation. In this study, we demonstrated that treatment with kaempferol protected mice from developing psoriasis-like skin lesions induced by topical administration of IMQ. Kaempferol reduced CD3+ T cell infiltration and gene expression of major proinflammatory cytokines, including interleukin (IL)-6, IL-17A and tumor necrosis factor (TNF)-α, in the psoriatic skin lesion. It also down-regulated proinflammatory nuclear factor kappa B (NF-κB) signaling in the skin. The therapeutic effects were associated with a significant increase in CD4+ forkhead box protein 3 (FoxP3)+ regulatory T cell (Treg ) frequency in the spleen and lymph nodes as well as FoxP3-positive staining in the skin lesion. Conversely, depletion of CD4+ CD25+ Tregs reversed the therapeutic effects of kaempferol on the skin lesion. Kaempferol also lowered the percentage of IL-17A+ CD4+ T cells in the spleen and lymph nodes of IMQ-induced psoriatic mice. Finally, kaempferol suppressed the proliferation of T cells in vitro and their mTOR signaling. Thus, our findings suggest that kaempferol may be a therapeutic drug for treating human psoriasis in the near future.

Anil Kumar N, Sharopov F, Ramírez-Alarcón K, Ruiz-Ortega A, Abdulmajid Ayatollahi S, Valere Tsouh Fokou P, Kobarfard F, Amiruddin Zakaria Z, Iriti M, Taheri Y, Martorell M, Sureda A, N. Setzer W, Durazzo A, Lucarini M, Santini A, Capasso R, Adrian Ostrander E, -ur-Rahman A, Iqbal Choudhary M, C. Cho W, Sharifi-Rad J. Antidiabetic Potential of Medicinal Plants and Their Active Components

Diabetes mellitus is one of the major health problems in the world, the incidence and associated mortality are increasing. Inadequate regulation of the blood sugar imposes serious consequences for health. Conventional antidiabetic drugs are effective, however, also with unavoidable side effects. On the other hand, medicinal plants may act as an alternative source of antidiabetic agents. Examples of medicinal plants with antidiabetic potential are described, with focuses on preclinical and clinical studies. The beneficial potential of each plant matrix is given by the combined and concerted action of their profile of biologically active compounds.

Antidiabetic Potential of Flavonoids from Traditional Chinese Medicine: A Review

Diabetes mellitus (DM) is a group of metabolic disorders in which high blood sugar levels occur over a prolonged period. Approximately 4% of the global population is affected by DM. Western medical treatment methods for diabetes including injection or oral hypoglycemic drugs have some toxic or side effects, economic pressures, and so on. Many researchers turn to discover new drugs from natural products or Traditional Chinese Medicine (TCM). Flavonoids are widely distributed in plants, and many studies have shown that flavonoids possess antidiabetic properties, exhibiting not only well-recognized antidiabetic and hypoglycemic activities but also activity in the treatment of diabetic complications. In this review, we systematically summarized anti-diabetic flavonoid compounds based on structure classification by examining the PubMed, Springer Link, Web of Science, and CNKI databases. There are 13 flavonoid compounds listed which have been studied extensively and have antidiabetic features respectively. Apigenin, baicalein, and catechin mainly reduces blood glucose via anti-oxidation; hesperidin is good for diabetic neuropathy; glycyrrhiza flavonoids have a significant effect on gestational DM; quercetin takes advantage of crossing the blood–brain barrier and improving renal function. Some compounds have protective and preventive effects on diabetic complications, such as kaempferol and puerarin which are beneficial to cardiomyopathy; myricetin has therapeutic potential in the treatment of DN; dihydromyricetin might improve CI. It is a pity or might be a pointcut that most studies remain in the animal experimental stage, and further investigation should be carried out.

Tinospora cordifolia preserves pancreatic beta cells and enhances glucose uptake in adipocytes to regulate glucose metabolism in diabetic rats

The purpose of this study was to evaluate the pancreatic beta cell protective and glucose uptake enhancing effect of the water extract of Tinospora cordifolia stem (TCSE) by using rat insulinoma (RIN)-m5F cells and 3 T3-L1 adipocytes. RIN-m5F cells were stimulated with interleukin-1β and interferon-γ, and the effect of TCSE on insulin secretion and cytokine-induced toxicity was measured by ELISA and MTT assay, respectively. The glucose uptake and protein expression were measured by fluorometry and western blotting. Antidiabetic effect of TCSE was measured using streptozotocin-induced diabetic rats. TCSE dose dependently increased cell viability and insulin secretion in RIN-m5F cells. In addition, TCSE increased both the glucose uptake and glucose transporter 4 translocation in 3 T3-L1 adipocytes via PI3K pathway. Finally, TCSE significantly lowered blood glucose and diet intake and increased body weight in streptozotocin-induced diabetic rats. The level of serum insulin and hepatic glycogen was increased, whereas the level of serum triglyceride, total cholesterol, dipeptidyl peptidase-4, and thiobarbituric acid reactive substances was decreased in TCSE-administered rats. TCSE also increased glucose transporter 4 protein expression in the adipose tissue and liver of TCSE-fed diabetic rats. Our results suggested that TCSE preserved RIN-m5F cells from cytokine-induced toxicity and enhanced glucose uptake in 3 T3-L1 adipocytes, which may regulate glucose metabolism in diabetic rats.

LC-MS/MS analysis and network pharmacology of Trigonella foenum-graecum - A plant from Ayurveda against hyperlipidemia and hyperglycemia with combination synergy

BACKGROUND

The seed of Trigonella foenum-graecum L. (Methika in Sanskrit) is a well known kaphahara (balancing kapha) herb in Ayurveda indicated in Prameha or early diabetes mellitus. It is also useful in obesity and reduces lipid level of blood.

PURPOSE

We aimed to explore the metabolites present in the plant extract and to establish the combination synergy and the network pharmacology along with the underlying the mechanism of action involved.

STUDY DESIGN

LC-MS/MS based metabolite screening followed by ADME screening and finally network pharmacology exploration of the mechanism of action involved against hyperlipidemia and hypolipidemia with neighbourhood based combination synergy approach.

METHODS

Ethanolic extract of Trigonella foenum-graecum L. (TFHE) was subjected to LC-MS/MS analysis to identify the active constituents. Oral bioavailability and drug likeness was screened for all the compounds. Databases- Binding DB, DAVID, KEGG and STRING were used to gather information to develop the networks. The networks were constructed using Cytoscape 3.2.1. Combination synergy analysis was performed with the help of Cytoscape network analyzer tool with neighbourhood approach.

RESULTS

The LC-MS/MS analysis identified 13 compounds which were found to be bio-available and drug like following the QED and Veber drug likeness parameters. The pathway analysis showed enrichment for different pathways like MAPK pathway (p-4.69E-07), JAK-STAT pathway (p-6.30E-05), Adipocytokine (p-0.00179), Type 2 Diabetes mellitus (0.00441), Insulin signalling pathway (p-0.0121), mTOR signalling pathway (p-0.000378), which are all connected to hyperlipidemia and hyperglycemia. The combination synergy network identified 23 targets interacting with 13 compounds based on a network neighbourhood approach.

CONCLUSION

The network pharmacology analysis strongly suggested the multimode evidences that TFHE largely works on the insulin signalling pathway and mainly based on its antioxidant potential due to its interaction with carbonic anhydrase. Various compounds were found to be interacting with key proteins that activates EGFR/AKT/mTOR signalling cascade which has therapeutic implication in hyperglycemia and hyperlipidemia. The combination synergy network analysis based on neighbourhood approach can help us in further understanding mechanism of multi-molecular fixed dose combinations.

Flavonoids and Insulin-Resistance: From Molecular Evidences to Clinical Trials

Insulin-resistance is one of the main factors responsible for the onset and progression of Metabolic Syndrome (MetS). Among all polyphenols, the effects of flavonoids and their main food sources on insulin sensitivity have been widely evaluated in molecular and clinical studies. The aim of this review is to analyse the data observed in vitro, in vivo and in clinical trials concerning the effects of flavonoids on insulin resistance and to determine the molecular mechanisms with which flavonoids interact with insulin signaling.

The protective effect of kaempferol on heart via the regulation of Nrf2, NF-κβ, and PI3K/Akt/GSK-3β signaling pathways in isoproterenol-induced heart failure in diabetic rats

This study was designed to delineate the effect of kaempferol (KF) on heart failure (HF) in diabetic rats. Streptozotocin-induced male diabetic rats received KF orally at 10 and 20 mg/kg for 42 consecutive days. In last 2 days of the experimental period, isoproterenol was subcutaneously injected at 85 mg/kg to induce HF. The hearts were processed for hemodynamic, biochemical, molecular, and histological investigations. Systolic blood pressure, diastolic blood pressure, and mean arterial blood pressure were elevated in KF-treated HF-induced diabetic rats. Moreover, KF treatment resulted in decreased fasting blood glucose and glycosylated hemoglobin levels with increased serum insulin levels. Besides, serum cardiac injury markers like troponin-I, creatine kinase-muscle/brain, lactate dehydrogenase, and brain natriuretic peptide levels were significantly reduced in KF treatment. KF treatment has shown decrease in cardiac heme oxygenase-1, nuclear factor erythroid 2-related factor 2 (Nrf-2), and γ-glutamylcysteine synthetase with increased Keap1 mRNA levels. The cardioprotection of KF was improved by inhibition of apoptosis via blocking phosphorylation of Akt/glycogen synthase kinase (GSK)-3β and p38 mitogen-activated protein-kinase/extracellular signal-regulated kinases signaling pathways in HF-induced diabetic rats. Moreover, reduced cardiac apoptosis in KF treatment was confirmed by decreased terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) positive cells, histopathological changes in HF-induced diabetic rats. Therefore, the cardioprotective effect of KF is attributed to the regulation of Nrf2, nuclear factor kappa-light-chain-enhancer of activated B cells, and Akt/GSK-3β signaling pathways in HF-induced diabetic rats.

Genetic and Phytochemical Characterization of Lettuce Flavonoid Biosynthesis Mutants

We previously developed red lettuce (Lactuca sativa L.) cultivars with high flavonoid and phenolic acid content and demonstrated their anti-diabetic effect. Here we report on developing three fertile and true-breeding lettuce lines enriched with flavonoids with reported beneficial health effects. These lines were identified in a segregating population of EMS-mutagenized red lettuce and characterized biochemically and genetically. Change in red coloration was used as a visual indicator of a mutation in a flavonoid pathway gene, leading to accumulation of flavonoid precursors of red anthocyanins. Pink-green kaempferol overproducing kfoA and kfoB mutants accumulated kaempferol to 0.6-1% of their dry weight, higher than in any vegetable reported. The yellow-green naringenin chalcone overproducing mutant (nco) accumulated naringenin chalcone, not previously reported in lettuce, to 1% dry weight, a level only observed in tomato peel. Kfo plants carried a mutation in the FLAVONOID-3' HYDROXYLASE (F3'H) gene, nco in CHALCONE ISOMERASE (CHI). This work demonstrates how non-GMO approaches can transform a common crop plant into a functional food with possible health benefits.

Effect of Kaempferol Pretreatment on Myocardial Injury in Rats

The present study was undertaken to evaluate the effect of kaempferol in isoprenaline (ISP)-induced myocardial injury in rats. ISP was administered subcutaneously for two subsequent days to induce myocardial injury. Assessment of myocardial injury was done by estimation of hemodynamic functions, myocardial infarcted area, cardiac injury markers, lipid profile, oxidative stress, pro-inflammatory cytokines and histopathology of heart and liver. Rats pretreated with kaempferol showed reduction in the myocardial infarcted area and heart rate. However, no improvement was observed in change in body weight, mean arterial, systolic and diastolic blood pressure. Kaempferol showed significant decrease in serum LDH, CK-MB, troponin-I and lipid profile. However, highest dose of kaempferol did not reduce the serum triglyceride level. Further, antioxidant enzymes, SOD and catalase, were also higher. However, reduced glutathione, serum SGOT and creatinine did not show any improvement. Kaempferol showed reduction in MDA level. Kaempferol at highest dose showed reduction in pro-MMP-2 expression and MMP-9 level. mRNA expression level of TNF-α was not different in kaempferol-pretreated myocardial injured rats with ISP-alone group. Pretreatment with kaempferol at highest dose showed mild mononuclear infiltration and degenerative changes in heart tissue section of myocardial injured rats. Rats pretreated with kaempferol at higher concentration showed normal cordlike arrangement of hepatocytes with moderate swelling of hepatocytes (vacuolar degeneration) around the central vein. Study suggests that kaempferol attenuated lipid profile, infarcted area and oxidative stress in ISP-induced myocardial injury in rats.

Chemo-preventive and therapeutic effect of the dietary flavonoid kaempferol: A comprehensive review

Kaempferol, a natural flavonoid present in several plants, possesses a wide range of therapeutic properties such as antioxidant, anticancer, and anti-inflammatory. It has a significant role in reducing cancer and can act as a therapeutic agent in the treatment of diseases and ailments such as diabetes, obesity, cardiovascular diseases, oxidative stress, asthma, and microbial contamination disorders. Kaempferol acts through different mechanisms: It induces apoptosis (HeLa cervical cancer cells), decreases cell viability (G2/M phase), downregulates phosphoinositide 3-kinase (PI3K)/AKT (protein kinase B) and human T-cell leukemia/lymphoma virus-I (HTLV-I) signaling pathways, suppresses protein expression of epithelial-mesenchymal transition (EMT)-related markers including N-cadherin, E-cadherin, Slug, and Snail, and metastasis-related markers such as matrix metallopeptidase 2 (MMP-2). Accordingly, the aim of the present review is to collect information pertaining to the effective role of kaempferol against various degenerative disorders, summarize the antioxidant, anti-inflammatory, anticancer, antidiabetic, and antiaging effects of kaempferol and to review the progress of recent research and available data on kaempferol as a protective and chemotherapeutic agent against several ailments.

Cardiovascular Effects of Flavonoids

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Cardiovascular Disease (CVD) is the major cause of death worldwide, especially in Western society. Flavonoids are a large group of polyphenolic compounds widely distributed in plants, present in a considerable amount in fruit and vegetable. Several epidemiological studies found an inverse association between flavonoids intake and mortality by CVD. The antioxidant effect of flavonoids was considered the main mechanism of action of flavonoids and other polyphenols. In recent years, the role of modulation of signaling pathways by direct interaction of flavonoids with multiple protein targets, namely kinases, has been increasingly recognized and involved in their cardiovascular protective effect. There are strong evidence, in in vitro and animal experimental models, that some flavonoids induce vasodilator effects, improve endothelial dysfunction and insulin resistance, exert platelet antiaggregant and atheroprotective effects, and reduce blood pressure. Despite interacting with multiple targets, flavonoids are surprisingly safe. This article reviews the recent evidence about cardiovascular effects that support a beneficial role of flavonoids on CVD and the potential molecular targets involved.

Ethanolic Extract of Folium Sennae Mediates the Glucose Uptake of L6 Cells by GLUT4 and Ca2

In today’s world, diabetes mellitus (DM) is on the rise, especially type 2 diabetes mellitus (T2DM), which is characterized by insulin resistance. T2DM has high morbidity, and therapies with natural products have attracted much attention in the recent past. In this paper, we aimed to study the hypoglycemic effect and the mechanism of an ethanolic extract of Folium Sennae (FSE) on L6 cells. The glucose uptake of L6 cells was investigated using a glucose assay kit. We studied glucose transporter 4 (GLUT4) expression and AMP-activated protein kinase (AMPK), protein kinase B (PKB/Akt), and protein kinase C (PKC) phosphorylation levels using western blot analysis. GLUT4 trafficking and intracellular Ca²⁺ levels were monitored by laser confocal microscopy in L6 cells stably expressing IRAP-mOrange. GLUT4 fusion with plasma membrane (PM) was observed by myc-GLUT4-mOrange. FSE stimulated glucose uptake; GLUT4 expression and translocation; PM fusion; intracellular Ca²⁺ elevation; and the phosphorylation of AMPK, Akt, and PKC in L6 cells. GLUT4 translocation was weakened by the AMPK inhibitor compound C, PI3K inhibitor Wortmannin, PKC inhibitor Gö6983, G protein inhibitor PTX/Gallein, and PLC inhibitor U73122. Similarly, in addition to PTX/Gallein and U73122, the IP3R inhibitor 2-APB and a 0 mM Ca²⁺-EGTA solution partially inhibited the elevation of intracellular Ca²⁺ levels. BAPTA-AM had a significant inhibitory effect on FSE-mediated GLUT4 activities. In summary, FSE regulates GLUT4 expression and translocation by activating the AMPK, PI3K/Akt, and G protein–PLC–PKC pathways. FSE causes increasing Ca²⁺ concentration to complete the fusion of GLUT4 vesicles with PM, allowing glucose uptake. Therefore, FSE may be a potential drug for improving T2DM.