Anti-diabetic activity of crude polysaccharide and rhamnose-enriched polysaccharide from G. lithophila on Streptozotocin (STZ)-induced in Wistar rats. Sci Rep. 2020;10:556. [PMID: 31953455 PMCID: PMC6969100 DOI: 10.1038/s41598-020-57486-w]

Atractylodes macrocephala Koidz. and Cuscuta chinensis Lam. extract relieves insulin resistance via PI3K/Akt signalling in diabetic Drosophila

Background and aim

Type-2 diabetes mellitus (T2DM) is mainly characterized by insulin resistance (IR) induced by hyperglycaemia and insufficient insulin secretion. We employed a diabetic fly model to examine the effect and molecular mechanism of Atractylodes macrocephala Koidz. and Cuscuta chinensis Lam. (AMK-CCL) extract as traditional Chinese medicine in treating IR and T2DM.

Experimental procedure

The contents of the active ingredients (rhamnose, xylose, mannose, and hyperoside) in AMK-CCL extract were determined by high-performance liquid chromatography. Wild-type (Cg-GAL4/+) or diabetic (Cg > InRK1409A) Drosophila flies were divided into the control group or metformin group and AMK-CCL (0.0125, 0.025, 0.05, 0.1 g/ml) groups. Food intake, haemolymph glucose and trehalose, protein, weight, triglycerides (TAG), and glycogen were measured to assess glycolipid metabolism. Phosphatidylinositol-3-kinase (PI3K)/Akt signalling was detected using fluorescent reporters [tGPH, Drosophila forkhead box O (dFoxO)-green fluorescent protein (GFP), Glut1-GFP, 2-NBDG] in vivo. Glut1/3 mRNA levels and Akt phosphorylation levels were detected by quantitative polymerase chain reaction and western blotting, respectively, in vitro.

Results

AMK-CCL extract contained 0.038 % rhamnose, 0.017 % xylose, 0.69 % mannose, and 0.039 % hyperoside. AMK-CCL at 0.0125 g/mL significantly suppressed the increase in circulating glucose, and the decrease in body weight, TAG, and glycogen contents of diabetic flies. AMK-CCL improved PI3K activity, Akt phosphorylation, Glut1/3 expression, and glucose uptake in diabetic flies, and also rescued diabetes-induced dFoxO nuclear localisation.

Conclusions

These findings indicate that AMK-CCL extract ameliorates IR-induced diabetes via the PI3K/Akt signalling pathway, providing an experimental basis for clinical treatment.

Pichia pastoris Mediated Digestion of Water-Soluble Polysaccharides from Cress Seed Mucilage Produces Potent Antidiabetic Oligosaccharides

Diabetes mellitus is a heterogeneous metabolic disorder that poses significant health and economic challenges across the globe. Polysaccharides, found abundantly in edible plants, hold promise for managing diabetes by reducing blood glucose levels (BGL) and insulin resistance. However, most of these polysaccharides cannot be digested or absorbed directly by the human body. Here we report the production of antidiabetic oligosaccharides from cress seed mucilage polysaccharides using yeast fermentation. The water-soluble polysaccharides extracted from cress seed mucilage were precipitated using 75% ethanol and fermented with Pichia pastoris for different time intervals. The digested saccharides were fractionated through gel permeation chromatography using a Bio Gel P-10 column. Structural analysis of the oligosaccharide fractions revealed the presence of galacturonic acid, rhamnose, glucuronic acid, glucose and arabinose. Oligosaccharide fractions exhibited the potential to inhibit α-amylase and α-glucosidase enzymes in a dose-dependent manner in vitro. The fraction DF73 exhibited strong inhibitory activity against α-amylase with IC50 values of 38.2 ± 1.12 µg/mL, compared to the positive control, acarbose, having an IC50 value of 29.18 ± 1.76 µg/mL. Similarly, DF72 and DF73 showed the highest inhibition of α-glucosidase, with IC50 values of 9.26 ± 2.68 and 50.47 ± 5.18 µg/mL, respectively. In in vivo assays in streptozotocin (STZ)-induced diabetic mice, these oligosaccharides significantly reduced BGL and improved lipid profiles compared to the reference drug metformin. Histopathological observations of mouse livers indicated the cytoprotective effects of these sugars. Taken together, our results suggest that oligosaccharides produced through microbial digestion of polysaccharides extracted from cress seed mucilage have the potential to reduce blood glucose levels, possibly through inhibition of carbohydrate-digesting enzymes and regulation of the various signaling pathways.

Ameliorative effect of montelukast against STZ induced diabetic nephropathy: targeting HMGB1, TLR4, NF-κB, NLRP3 inflammasome, and autophagy pathways

Diabetic nephropathy (DN) is reported as one of the most serious microvascular diabetic complications and the trigger of end-stage renal disease (ESRD), underscoring the concern of any therapeutic intervention directed at ameliorating the development and progression of DN. The current study explored the renoprotective impact of montelukast (Mon) against streptozotocin (STZ)-induced DN in rats compared to a standard anti-hyperglycemic insulin (Ins) treatment. Diabetes was induced by a single dose of STZ (55 mg/kg). Diabetic rats were treated with Mon (10 and 20 mg/kg, oral gavage) for eight weeks. Mon administration for 8 weeks after induction of diabetes conferred significant dose-dependent renoprotection, independent of blood glucose levels (unlike Ins), as evidenced by the improvement in serum creatinine, and blood urea nitrogen (BUN), and ameliorated STZ-induced renal necrotic, inflammatory alterations, and renal fibrosis. Additionally, Mon treatment in diabetic rats significantly restored redox hemostasis as evidenced by malondialdehyde (MDA) and total antioxidant capacity (TAC) levels; significantly reduced the renal expression of high mobility group box (HMGB) 1, toll-like receptor (TLR) 4, nuclear factor kappa B (NF-κB) (in the nucleus), NOD-like receptor family pyrin domain containing (NLRP) 3, and interleukin (IL)-1β. Moreover, Mon administration ameliorated the dysregulation in autophagy as evidenced by p62 and microtubule-associated protein 1A/1B-light chain 3 (LC3)-II levels. In conclusion, the renoprotective effect of Mon is potentially associated with its modulatory effect on inflammatory cytokines, antioxidant properties, and autophagy.

A review on the hypoglycemic effect, mechanism and application development of natural dietary polysaccharides

Diabetes mellitus (DM) as one chronic metabolic disease was greatly increased over recent decades. The major agents treating diabetes have noticeable side effects as well as the tolerability problems. The bioactive dietary polysaccharides from abundant natural resources exhibit good hypoglycemic effect with rare adverse effects, which might serve as a candidate to prevent and treat diabetes. However, the correlations between the hypoglycemic mechanism of polysaccharides and their structure were not mentioned in several studies, what's more, most of the current hypoglycemic studies on polysaccharides were based on in vitro and in vivo experiments, and there was a lack of knowledge about the effects in human clinical trials. The aim of this review is to discuss recent literature about the variety of dietary polysaccharides with hypoglycemic activity, as well the mechanism of action and the structure-function relationship are highlighted. Meanwhile, the application of dietary polysaccharides in functional foods and clinical medicine are realized with an in-depth understanding. So as to promote the exploration of dietary polysaccharides in low glycemic healthy foods or clinical medicine to prevent and treat diabetes.

CysLTR1 antagonism by montelukast can ameliorate diabetes-induced aortic and testicular inflammation

AIMS

Montelukast, a cysteinyl leukotriene receptor (CysLTR)1 antagonist, is emerging as an attractive strategy to curtail diabetic complications; however, its role in aortic and testicular tissues is unknown. This study investigated the effect of CysLTR1 antagonism by montelukast on toll-like receptor (TLR)4 and nuclear factor kappa B (NF-κB) pathways in diabetes-induced aortic and testicular injury.

METHODS

Adult male Sprague-Dawley rats were made diabetic with Streptozotocin (STZ, 55 mg/kg). Following this, Streptozotocin-induced diabetic (SD) rats were administered montelukast (10 and 20 mg/kg, orally) for 8 weeks. Blood glucose, serum malondialdehyde (MDA), inflammatory markers, and histopathology were evaluated.

RESULTS

Montelukast showed protection against diabetic complications, as evidenced by the ameliorative effect against STZ-induced alterations in oxidative stress as indicated by serum MDA levels. Moreover, montelukast conferred a significant decrease in the aortic and testicular levels of CysLTR1, TLR4, and NF-κB with a subsequent decrease in the levels of NOD-like receptor family pyrin domain containing (NLRP)3, caspase 1, interleukin (IL)-1β, IL-6, monocyte chemoattractant protein (MCP)-1, and tumor necrosis factor (TNF)-α. Additionally, administration of montelukast resulted in autophagy stimulation, as shown by decreased p62/Sequestosome (SQSTM)1 levels. Finally, montelukast protection resulted in normal thickness of whole aortic wall, regular tunica (t.) intima, mild vacuolation of smooth muscle fibers in aorta, increased size of seminiferous tubules, and increased spermatogenesis in testis as demonstrated by histopathology.

CONCLUSIONS

The protective effect of montelukast against diabetes-induced aortic and testicular injury is due to its antioxidant, anti-inflammatory, and autophagy stimulation characteristics.

Melatonin and probiotic administration ameliorated hyperglycaemia, oxidative stress, and enhanced cytoprotective effect on beta-cells of diabetic rats

Objective

The study aimed at investigating the effects of administering melatonin and a probiotic to streptozotocin-induced diabetic rats on hyperglycaemia, oxidative stress biomarkers and beta-cells.

Design

Type 1 diabetes was induced in 5 months-old male Wistar rats by single intraperitoneal (i.p.) administration of freshly-prepared STZ (60 mg/kg body weight). Six groups of 10 rats were used and treated once daily for six weeks; (1) Healthy control: normal saline only; (2) Pre-treated with Melatonin (MEL); (3) Diabetic control; (4) Diabetic + Treated with MEL; (5) Diabetic + Treated with Probiotic (Prob); (6) Diabetic + Treated with MEL + Prob. Blood glucose, body weight, activities of antioxidant enzymes and malondialdehyde concentration in serum and tissues, reduced glutathione and immunohistochemical assay. Data obtained were expressed as mean ± standard error of the mean (Mean ± SEM) and subjected to ANOVA followed by Tukey's post hoc test.

Results

Melatonin + Probiotic significantly decreased blood glucose concentrations in diabetic treated rats, compared to the diabetic control rats. MEL + Probiotic increased (p < 0.05) superoxide dismutase activity in serum and liver of diabetic rats. MEL + Probiotic reduced (p < 0.05) malondialdehyde concentration in the serum, liver and kidneys, respectively. MEL + Probiotic treated diabetic rats displayed islets with much greater content of insulin.

Conclusion

Melatonin + Probiotic combination was more effective in mitigating hyperglycaemia, oxidative stress, and exerted cytoprotective effect on the beta-cells.

Therapeutic Potentials of Microalgae and Their Bioactive Compounds on Diabetes Mellitus

Diabetes mellitus is a metabolic disorder characterized by hyperglycemia due to impaired insulin secretion, insulin resistance, or both. Oxidative stress and chronic low-grade inflammation play crucial roles in the pathophysiology of diabetes mellitus. There has been a growing interest in applying natural products to improve metabolic derangements without the side effects of anti-diabetic drugs. Microalgae biomass or extract and their bioactive compounds have been applied as nutraceuticals or additives in food products and health supplements. Several studies have demonstrated the therapeutic effects of microalgae and their bioactive compounds in improving insulin sensitivity attributed to their antioxidant, anti-inflammatory, and pancreatic β-cell protective properties. However, a review summarizing the progression in this topic is lacking despite the increasing number of studies reporting their anti-diabetic potential. In this review, we gathered the findings from in vitro, in vivo, and human studies to discuss the effects of microalgae and their bioactive compounds on diabetes mellitus and the mechanisms involved. Additionally, we discuss the limitations and future perspectives of developing microalgae-based compounds as a health supplement for diabetes mellitus. In conclusion, microalgae-based supplementation has the potential to improve diabetes mellitus and be applied in more clinical studies in the future.

Melatonin downregulates the increased hepatic alpha-fetoprotein expression and restores pancreatic beta cells in a streptozotocin-induced diabetic rat model: a clinical, biochemical, immunohistochemical, and descriptive histopathological study

Background

Diabetes mellitus (DM) is a chronic metabolic disorder. Hepatopathy is one of the serious effects of DM Melatonin (MT) is a potent endogenous antioxidant that can control insulin output. However, little information is available about the potential association between melatonin and hepatic alpha-fetoprotein expression in diabetes.

Objective

This study was conducted to assess the influence of MT on diabetes-related hepatic injuries and to determine how β-cells of the pancreas in diabetic rats respond to MT administration.

Materials and methods

Forty rats were assigned to four groups at random (ten animals per group). Group I served as a normal control group. Group II was induced with DM, and a single dose of freshly prepared streptozotocin (45 mg/kg body weight) was intraperitoneally injected. In Group III, rats received 10 mg/kg/day of intraperitoneal melatonin (IP MT) intraperitoneally over a period of 4 weeks. In Group IV (DM + MT), following the induction of diabetes, rats received MT (the same as in Group III). Fasting blood sugar, glycosylated hemoglobin (HbA1c), and serum insulin levels were assessed at the end of the experimental period. Serum liver function tests were performed. The pancreas and liver were examined histopathologically and immunohistochemically for insulin and alpha-fetoprotein (AFP) antibodies, respectively.

Results

MT was found to significantly modulate the raised blood glucose, HbA1c, and insulin levels induced by diabetes, as well as the decreased alanine aminotransferase (ALT) and aspartate aminotransferase (AST). Furthermore, MT attenuated diabetic degenerative changes in the pancreas and the hepatic histological structure, increased the β-cell percentage area, and decreased AFP expression in the liver tissue. It attenuated diabetes-induced hepatic injury by restoring pancreatic β-cells; its antioxidant effect also reduced hepatocyte injury.

Conclusion

Collectively, the present study confirmed the potential benefits of MT in downregulating the increased hepatic alpha-fetoprotein expression and in restoring pancreatic β-cells in a streptozotocin-induced diabetic rat model, suggesting its promising role in the treatment of diabetes.

Discovery of imeglimin-inspired novel 1,3,5-triazine derivatives as antidiabetic agents in streptozotocin-induced diabetes in Wistar rats via inhibition of DPP-4

Novel 1,3,5-triazine derivatives bearing oxazine have been synthesized and tested for their ability to inhibit a panel of dipeptidyl peptidase (DPP)-4, 8, and 9 enzymes. In a comparative inhibitory assay, the molecules showed potent inhibition of DPP-4 ranging from IC50 of 4.2 ± 0.30-260.5 ± 0.42 nM, with no activity against DPP-8 and DPP-9. Among the tested series, compound 8c demonstrated the strongest DPP-4 inhibitory activity with an IC50 of 4.2 ± 0.30 nM. It also showed the greatest binding affinity during docking studies with DPP-4 with a docking score of -8.956 and a glide energy of -78.546 kcal mol-1 and was found oriented in the S1 and S2 pockets of the DPP-4 active site, which is composed of the catalytic triad Ser 630, Asp 710, and His 740. The in vivo pharmacological assay revealed that compound 8c in a dose-dependent manner improved the insulin level, body weight, antioxidants, and HDL, and reduced the levels of blood glucose, LDL, and VLDL in streptozotocin-induced diabetes in Wistar rats. Our study demonstrated the discovery and development of novel 1,3,5-triazine derivatives bearing oxazine as a novel class of anti-diabetic agents via inhibition of DPP-4.

The Impact of Resveratrol-Enriched Bread on Cardiac Remodeling in a Preclinical Model of Diabetes

The World Health Organization aims to stop the rise of diabetes by 2025, and diet is one of the most efficient non-pharmacological strategies used to prevent it. Resveratrol (RSV) is a natural compound with anti-diabetic properties, and incorporating it into bread is a suitable way to make it more accessible to consumers as it can be included as part of their daily diet. This study aimed to evaluate the effect of RSV-enriched bread in preventing early type 2 diabetes cardiomyopathy in vivo. Male Sprague Dawley rats (3 weeks old) were divided into four groups: controls with plain bread (CB) and RSV bread (CBR), and diabetics with plain bread (DB) and RSV bread (DBR). Type 2 diabetes was induced by adding fructose to the drinking water for two weeks followed by an injection of streptozotocin (STZ) (40 mg/kg). Then, plain bread and RSV bread (10 mg RSV/kg body weight) were included in the rats' diet for four weeks. Cardiac function, anthropometric, and systemic biochemical parameters were monitored, as well as the histology of the heart and molecular markers of regeneration, metabolism, and oxidative stress. Data showed that an RSV bread diet decreased the polydipsia and body weight loss observed in the early stages of the disease. At the cardiac level, an RSV bread diet diminished fibrosis but did not counteract the dysfunction and metabolic changes seen in fructose-fed STZ-injected rats.

Polysaccharides as antioxidants and prooxidants in managing the double-edged sword of reactive oxygen species

Polysaccharides, a class of naturally occurring carbohydrates, were widely presented in animals, plants, and microorganisms. Recently, health benefits of polysaccharides have attracted much attention due to their unique characteristics in reactive oxygen species (ROS) management. ROS, by-products of aerobic metabolism linked to food consumption, exhibited a dual role in protecting cells and fostering pathogenesis collectively termed double-edged sword. Some interesting studies reported that polysaccharides could behave as prooxidants under certain conditions, besides antioxidant capacities. Potentiation of the bright side of ROS could contribute to the host defense that was vitally important for the polysaccharides acting as biological response modifiers. Correspondingly, disease prevention of polysaccharides linked to the management of ROS production was systematically described and discussed in this review. Furthermore, major challenges and future prospects were presented, aiming to provide new insight into applying polysaccharides as functional food ingredients and medicine.

Mechanistic Insight of Synthesized 1,4-Dihydropyridines as an Antidiabetic Sword against Reactive Oxygen Species

The pharmacologically privileged DHP derivatives were synthesized using the pragmatic multicomponent Hantzsch synthesis to screen the antidiabetic activity. Initially, the candidates were screened using an in vivo blood glucose test, where compound 8b showed the most prominent antidiabetic effect (% potency = 218%) compared to glimepiride. Then, a propositioned structure-activity relationship study was executed to reveal that longer side chains decreased the DHP's antidiabetic action. Mechanistically, compound 8b diminished ROS in β-cells and muscle cells simultaneously, which was proved by enhanced serum biochemical markers. Also, compound 8b decreased blood glucose by α-glucosidase inhibition (IC₅₀ = 4.48 ± 0.32 μM), compared to acarbose (7.40 ± 0.41 μM), based selectively on the plasma window of 8b. Acarbose demonstrated auspicious inhibitor activity according to the binding affinity (ΔG_binding), which was slightly lower than that of compound 8b (-54.7 and -46.8 kcal/mol, respectively). During the 100 ns molecular dynamics simulations, the structural and energetic assessments exposed the high consistency of compound 8b to bind to the α-glucosidase.

Design and Evaluation of Solid Lipid Nanoparticles Loaded Topical Gels: Repurpose of Fluoxetine in Diabetic Wound Healing

The current study aimed to prepare a topical gel containing solid lipid nanoparticles (SLNs) encapsulating fluoxetine for diabetic wound healing effects. Fluoxetine (FX) was loaded into SLNs by employing an emulsion solvent evaporation technique using stearic acid as a lipid, and soya lecithin as a surfactant. SLNs were then evaluated for particle size, polydispersity index (PDI), zeta potential (ZP), percent entrapment efficiency (%EE), percent drug loading (%DL), and in vitro drug release. The optimized SLN (FS3) composed of FX (100 mg), SA (150 mg), and SA (100 mg) displayed mean particle size (467.3 ± 2.2nm), PDI (0.435 ± 0.02), ZP (-32.2 ± 4.47mV), EE (95.8 ± 3.38%), and DL (16.4 ± 2.4%). FTIR and DSC studies denote drug-polymer compatibility and the amorphous nature of FX in the SLNs. The drug release at 24 h was found to be (98.89 ± 2.57%) which followed the fickian diffusion mechanism. SLN (FS3) was further loaded into carbopol gel and tested for pH, spreadability, and extrudability of pharmaceutical parameters. In-vitro release of FX from the SLN gel and plain gel was compared, diabetic wound healing gel (DWH) showed sustained drug delivery. An in vivo study was also performed for DWH gel in streptozotocin-induced diabetic rats. Histopathological examination exhibited DWH gel-treated wounds have increased hydroxyproline, cellular proliferation, a rise in the number of blood vessels, and the level of collagen synthesis. Thus, DWH gel-loaded SLN encapsulated with FX could be a potential carrier for the effective treatment and management of diabetic wounds.

In vivo Antihyperglycemic and Antidyslipidemic Effects of L-Tartaric Acid

AIMS

The aim of the study was to investigate the antihyperglycemic effect of L-Tartaric acid.

BACKGROUND

L-Tartaric acid is a natural product with possible beneficial effects on health.

OBJECTIVE

The goal of this work was to evaluate the antihyperglycemic and antidyslipidemic effects of L-Tartaric acid (L-TA) in rats.

MATERIALS AND METHODS

In the first model, the effects of L-TA (10 and 40 mg/kg) on diabetes conditions induced by streptozotocin (STZ) in rats were investigated. In the second model, the effects of L-TA (40 and 80 mg/kg) on dyslipidemia induced by tyloxapol (Triton WR-1339) in rats were assessed.

RESULTS

L-TA (40 mg/kg) had improved all studied parameters. L-TA at 40 mg/kg was able to significantly reduce glycaemia, improve oral glucose tolerance (OGT), increase glycogen content in liver and extensor digitorum longus (EDL) muscle, and ameliorate the lipidic profile and atherogenic indices in STZ-diabetic rats.

CONCLUSION

L-Tartaric acid was able to exhibit antihyperglycemic and antidyslipidemic effects in STZ-induced diabetic rats. Moreover, the antidyslipidemic effect of L-Tartaric acid was confirmed in tyloxapol-induced hyperlipidemic rats.

Upregulation of Antioxidative Gene Expression by Lasia spinosa Organic Extract Improves the Predisposing Biomarkers and Tissue Architectures in Streptozotocin-Induced Diabetic Models of Long Evans Rats

Plants are an entity essential to the function of the biosphere as well as human health. In the context of human health, this research investigated the effect of Lasia spinosa (Lour) leaf methanolic extracts (LSML) on antioxidative enzymes and gene expression as well as biochemical and histological markers in a streptozotocin (STZ)-induced diabetes model. Fructose-fed streptozotocin (STZ)-induced diabetic animals were subjected to a four-week intervention followed by the assessment of the animal’s blood and tissues for enzymatic, biochemical, histological, and genetic changes. LSML-treated groups were shown to decrease plasma glucose levels and improve body and organ weights compared to the untreated group in a dose-dependent manner. At the doses of 125 and 250 mg/kg b.w., LSML were able to normalize serum, hepatic, and renal biochemical parameters and restore the pancreas, kidney, liver, and spleen tissue architectures to their native state. A considerable increase (p < 0.01) of liver antioxidant enzymes CAT, SOD, GSH, and a decrease of MDA level in LSML-treated groups were found at higher doses. The improved mRNA expression level of antioxidant genes CAT, SOD2, PON1, and PFK1 was also found at the doses of 125 mg/kg and 250 mg/kg BW when compared to untreated control groups. The results demonstrate that LSML impacts the upregulation of antioxidative gene expressions, thus improving the diabetic complications in animal models which need to be affirmed by compound-based antioxidative actions for therapeutic development.

α-Glucosidase, α-amylase inhibition kinetics, in vitro gastro-intestinal digestion, and apoptosis inducing abilities of Ficus microcarpa L. f. and Ficus racemosa L. fruit polysaccharides

A rich source of nutrients, figs have a number of clinically validated benefits. This study aimed to evaluate the in vitro simulated gastrointestinal digestion, and the antidiabetic and anticancer activity of Ficus microcarpa (FMP) and F. racemosa (FRP) fruits polysaccharides. The pre-digested FMP revealed higher sugar content (721 ± 14.81 mg glucose equivalents/g sample) than FRP. After in vitro digestion, isolated fruit polysaccharides showed effective uptake with over 80% sugar loss. Free radicals and enzymatic inhibition after gastric digestion have been significantly modified, demonstrating the effective absorption of FMP and FRP through the intestine. Conversely, after the continuous digestion, the nutritional content of the isolated polysaccharides was gradually decreased compared to the pre-digested sample. At 30 µg/mL concentration of FMP and FRP was inhibited by 50% of breast cancer cells. The present study reveals the potential uptake of FMP and FRP as nutritional supplements in the future.

Graphical abstract

Assessment of biochemical changes in normal and diabetic rats treated by phenolic enriched extracts of Juglans regia L. barks

OBJECTIVES

Juglans regia L. is largely used by diabetic population, but its bark is scarcely investigated. The major aim of this study was to investigate the effect of the hydro-methanolic extract and fractions of J. regia L. barks on normoglycemic and diabetic rats through the evaluation of some biochemical parameters.

METHODS

Phenolic enriched extracts were investigated for their effect on normoglycemic and diabetic rats through the determination of fasting blood glucose levels in short- and long-term. As well as plasma total cholesterol, triglycerides, insulin, urea, creatinine, alanine amino transferase (ALT) and aspartate amino transferase (AST) levels were measured after 28 days of treatment. Furthermore, the phytochemical composition was assessed by standard methods.

RESULTS

Among the different extracts tested, the n-Butanol fraction presented the highest amounts of total phenolic, total flavonoids and flavonol contents (745 ± 0.6 mg GAE g^-1, 162 ± 0.78 mg CE g^-1 and 56.02 ± 0.92 mg QE g^-1, respectively) and it found to be the most effective to decrease plasma total cholesterol, triglycerides and FGLs in treated diabetic rats in both short- and long-term treatment, mainly the dose 200 mg/kg after 28 days of treatment which found to be more effective than glibenclamide. This fraction also revealed pronounced improvement in liver and renal profiles.

CONCLUSIONS

J. regia L. barks had an important antidiabetic role similar to the reference glibenclamide. This may be related to the high contents of phenolic compounds.

Research Progress on the Therapeutic Effect of Polysaccharides on Non-Alcoholic Fatty Liver Disease through the Regulation of the Gut–Liver Axis

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease affecting global public health at present, which can induce cirrhosis and liver cancer in serious cases. However, NAFLD is a multifactorial disease, and there is still a lack of research on its mechanism and therapeutic strategy. With the development of the gut–liver axis theory, the association between the gut–liver axis and the pathogenesis of NAFLD has been gradually disclosed. Polysaccharides, as a kind of natural product, have the advantages of low toxicity, multi-target and multi-pathway action. It has been reported that polysaccharides can affect the gut–liver axis at multiple interrelated levels, such as maintaining the ecological balance of gut microbiota (GM), regulating the metabolites of GM and improving the intestinal barrier function, which thereby plays a protective role in NAFLD. These studies have great scientific significance in understanding NAFLD based on the gut–liver axis and developing safe and effective medical treatments. Herein, we reviewed the recent progress of polysaccharides in improving nonalcoholic fatty liver disease (NAFLD) through the gut–liver axis.

Fruit Extract Derived from a Mixture of Noni, Pineapple and Mango Capable of Coagulating Milk and Producing Curd with Antidiabetic Activities

Research background

Morinda citrifolia L. (noni), Ananas comosus L. cv. Sarawak (pineapple) and Mangifera indica L. cv. Apple (mango) represent fruits capable of coagulating milk and forming a curd. Plant-derived milk coagulants have antidiabetic phytochemicals that enrich the curd. Hence this work evaluates the dual benefits of the fruits in coagulating milk and the antidiabetic activities found in the obtained curd.

Experimental approach

The three fruits were mixed to form a supercoagulant (a milk coagulant mixture of the extracts at a ratio of 1:1:1), and the milk coagulation time was measured. The milk was coagulated by the supercoagulant, and thus fortified curd was tested for its ability to inhibit α-glucosidase and α-amylase activities. Then, the fortified curd was fed daily to streptozotocin-induced diabetic rats and their biochemical markers such as blood glucose level, aspartate aminotransferase, alanine transaminase, etc. as well as histopathology of their liver and kidney tissues were compared with the untreated diabetic rats and normal rats.

Results and conclusion

The supercoagulant had a milk coagulation time of (28±3) s at a 50 mg/mL concentration. Its fortified curd inhibited α-glucosidase and α-amylase activities, with IC50 values of (4.04±0.03) and (3.42±0.02) mg/mL, respectively. The average mass of the streptozotocin-induced diabetic rats fed daily with curd formed by the supercoagulant was (201±10) g on day 20 compared to diabetic control rats with (149±16) g. The blood glucose concentration for rats treated with the supercoagulant after fasting was (15±1) mmol/L compared to the diabetic control rats ((26±2) mmol/L). Blood tests on the treated rats showed aspartate aminotransferase, alanine transaminase, γ-glutamyl transferase and alkaline phosphatase (liver function tests) amounts of (214±78), (91±13), 3 and (510±138) U/L, respectively, while the total protein and renal function tests showed the concentrations of albumin, globulin, urea and creatinine of (37±2) g/L, (30±2) g/L, (11±1) mmol/L and (42±3) µmol/L, respectively. These concentrations were found to be similar to those of the normal rats on day 20. Furthermore, a histopathological study performed on the liver and kidney of the rats found no apparent damage.

Novelty and scientific contribution

This supercoagulant derived from a mixture of fruits is able to coagulate milk rapidly, and its curd is fortified with safe antidiabetic agents. The supercoagulant is potentially useful in producing functional dairy food to prevent diabetes or as a supplement for diabetics to control their blood sugar. Such products are capable of replacing dairy products derived from animal enzymes and provide consumers with additional functional dairy products.

Comparison of pharmacokinetic parameters of ranolazine between diabetic and non-diabetic rats

OBJECTIVES

Diabetes mellitus (DM) affects the pharmacokinetics of drugs. Ranolazine is an antianginal drug that is prescribed in DM patients with angina. We decided to evaluate the effect of DM on the pharmacokinetics of ranolazine and its major metabolite CVT-2738 in rats.

MATERIALS AND METHODS

Male rats were divided into two groups: DM (induced by 55 mg/kg Streptozotocin (STZ)) and non-DM. All animals were treated with 80 mg/kg of ranolazine for 7 continuous days. The blood samples were collected immediately at 0 (prior to dosing), 1, 2, 3, 4, 8, and 12 hr after administration of the 7th dose of ranolazine. Serum ranolazine and CVT-2738 concentrations were determined using the high-performance liquid chromatography (HPLC) method. Pharmacokinetic parameters were calculated using a non-compartmental model and compared between the two groups.

RESULTS

The peak serum concentration (Cmax) and area under the curve (AUC) of ranolazine significantly decreased in DM compared with non-DM rats. DM rats showed significantly higher volumes of distribution (Vd) and clearance (CL) of ranolazine than non-DM rats. DM did not affect Ke, Tmax, and T1/2 of ranolazine. The concentration of metabolite was lower than the HPLC limit of detection (LOD).

CONCLUSION

It was found that streptozotocin-induced DM increased Vd and CL of ranolazine, thereby decreasing the AUC of the drug. Therefore, dosage adjustment may be necessary for DM patients, which requires further clinical studies.

L-Methionine prevents β-cell damage by modulating the expression of Arx, MafA and regulation of FOXO1 in type 1 diabetic rats

L-Methionine (L-Met) is an essential sulphur-containing amino acid having a vital role in various key cellular processes. Here we investigated the effect of L-Met on streptozotocin-induced β-cell damage model of diabetes mellitus in Sprague Dawley rats. At the end of study biochemical parameters, immunoblotting, qRT-PCR and ChIP-qPCR are performed. L-Met was administered orally (250 and 500 mg/kg/day) to diabetic animals for 8 weeks improved plasma glucose and insulin levels. Pancreas immunohistochemistry showed significant increase in insulin expression, decrease in glucagon and Bax expression. Interestingly, L-Met inhibited the expression of Arx; upregulated MafA and FOXO1 which play a critical role in the maintenance of β-cell identity. Our data also showed a decrease in H3K27me3 and an increase in H3K4me3 ("bivalent domain" alteration) in diabetic rats and these recovered by L-Met. Furthermore, the chromatin-immunoprecipitation assay showed a decreased enrichment of H3K27me3 on the promoter of the FOXO1 gene in diabetic rats and L-Met prevents this decrease. Our results showed the first evidence of the involvement of H3K27me3 in regulating the expression of the FOXO1 gene and the prevention of β-cell injury by L-Met treatment. In conclusion, we report the involvement of L-Met in the modulation of α-cell identity marker (Arx), β-cell identity marker (MafA) and regulation of FOXO1 by histone methylation marks for the first time. We are of the opinion that this employed as a novel therapeutic approach for mitigating diabetes-induced β-cell death.

Fustin ameliorates hyperglycemia in streptozotocin induced type-2 diabetes via modulating glutathione/Superoxide dismutase/Catalase expressions, suppress lipid peroxidation and regulates histopathological changes

Streptozotocin (STZ) 60 mg/kg, i.p.-induced diabetes in rat’s results into hyperglycemia, impaired oxidative stress, lipid profile, insulin levels and changes in body weight. Treatment with antihyperglycemics and antioxidants are accounted to produce favorable effect in this paradigm. Fustin, a flavonoid derived from Rhus verniciflua, extract of Rhus verniciflua reported to exhibit anti-hyperglycemic, antioxidant, anti-microbial, anti-arthritic effects, anti-obesity effects, antiplatelet effects and anti-cancer effects. However, no evidence is existing on effect of fustin on STZ-induction diabetes. Thus, we evaluated its effects against diabetes in STZ-induced rodents. Blood glucose, Insulin, lipid peroxidation (MDA), superoxide dismutase (SOD), catalase activity (CAT), glutathione (GSH) and lipid profile levels was assessed. After 30 days diabetes induction rodents showed a severe increased blood sugar level, MDA, high density lipid and decreased cholestrol, triglyceride, GSH, SOD, CAT, respectively.

Oppositely, treatment with fustin (50–100 mg/kg/p.o., two times daily, 30 days) enhanced blood glucose, lipid profile levels Insulin. Meanwhile, reduced MDA and enhanced GSH, SOD, and CAT in diabetic rats. Glibenclamide 5 mg/kg/p.o. also enhanced diabetes-induced complications and decreased oxidative stress. Further histopathology of pancreas confirms the protective effect fustin in STZ-induction diabetes in animals. In conclusion, the study revealed treatments with fustin avoid the changes in body weight, blood glucose, lipid profile and oxidative stress. As a results of these finding may lead to the growth of a choice of medicine for hyperglycemic in the future.

Evaluation of Antidiabetic Activity of Sargassum tenerrimum in Streptozotocin-Induced Diabetic Mice

Diabetes mellitus has become the most predominant disease in most of the developing and developed countries. Diabetes could occur at any stage of life for which a change in sedentary life style is the possible solution. Despite the introduction of several medications, to curtail the side effects associated with diabetes mellitus, there is no medication or treatment for complete cure. Existing medications and treatments are targeted to mitigate the intensity of the disease which abruptly could result in organ failure. Rather than the available types of treatments, natural medication is reported to produce commendable results. Extracts of many medicinal plants and seaweeds have been documented to possess anti-diabetic properties. A brown alga, S. tenerrimum, found on the west coast of India, is chosen in this study to analyse the anti-diabetic property of its methanolic extract. This extract was used to treat streptozotocin-induced diabetic mice. An experimental design was framed based on acute toxicity studies to determine the change in blood glucose level, body weight, lipid profile, liver enzymes (SGPT and SGOT) and the renal function markers (urea and creatinine). After 15 days of treatment, an increase in body weight and HDL cholesterol was observed while the total cholesterol, VLDL, LDL, serum triglyceride, SGOT, SGPT, creatinine and urea decreased with 250 mg/Kg.bw of S. tenerrimum methanolic extract in Streptozotocin-induced diabetic mice group. This difference is significant (p<0.05) when compared with a healthy non-diabetic mice group and a treated diabetic mice group. This proves that the methanolic extract of S. tenerrimum possess anti-diabetic property. Further research could explore the active compounds that can be used in the formulation of herbal medicine for diabetes mellitus.

Biofunctionalities of unprocessed and processed flours of Australian lupin cultivars: Antidiabetic and organ protective potential studies

As lupin has emerged popularity as dietary protein and nutritional source, our present research was aimed to demonstrate the antidiabetic and organ-protective activities of nine cultivars of Australian sweet lupin seed flours by means of in vitro and in vivo assays accompanied by identification of their bioactive phytocompounds and exploration of underlying mechanisms of their hypoglycemic activity using in silico approach. In vitro α-amylase and α-glucosidase activities inhibition and glucose uptake assays identified Jenabillup seed flours for exhibiting the most potential antidiabetic activity amongst the nine cultivars. In vivo antidiabetic and major organ-protective activities were investigated on streptozotocin-induced hyperglycemia and organ damages in Wister rat model. Along with attenuating hyperglycemia and retreating major organ damages, the biochemical imbalance in cardiac, hepatic and renal markers were well-balanced by Jenabillup seed flours treatment. These activities of lupin seed flours were insignificantly affected by thermal processing. Moreover, in silico investigation of 106 phytochemicals identified by gas chromatography-mass spectroscopy (GC-MS) analysis of the seed flour extracts of nine cultivars revealed that more than 35% of compounds possess moderate to high binding affinity to α-amylase and α-glucosidase enzymes. These bioactive compounds act synergistically to exert potential hypoglycemic activity. Cross-docking and binding energy calculation by molecular mechanics/generalized Born volume integration (MM/GBVI) model suggest actinomycin C2 as a potential inhibitor of both α-amylase and α-glucosidase enzymes. These findings acclaim that Australian sweet lupin seed flours may be considered not only as functional food, but also for further development of effective drugs in pharmaceuticals in the treatment of diabetes mellitus and resultant organ damages.

Diabetes mellitus aggravates ranolazine-induced ECG changes in rats

PURPOSE

Diabetes mellitus (DM) is known to affect the pharmacokinetics of drugs. In this study, we evaluated the effect of DM on the liver content of CYP 3A2 enzyme. We also explored the ECG changes after administration of ranolazine in non-DM and DM rats.

METHODS

First phase: 24 male Wistar rats were separated into 4 groups. The control group (n = 6) received normal saline and the DM groups (n = 18) were treated with a single dose (55 mg/kg) of streptozocin (STZ; i.p. injection), then were held for 10, 20, and 30 days, respectively. After study duration for each group, the liver CYP 3A2 protein content was determined using western blotting. Second phase: 48 male Wistar rats were classified into two groups of non-DM and DM; and each group was divided into 4 subgroups (n: 6). Experimental groups received oral doses of 20, 40, and 80 mg/kg ranolazine. DM and non-DM control groups received normal saline. Treatment lasted for 28 days, and then the ECG was recorded.

RESULTS

Experimental DM induced by STZ caused a significant decrement in liver CYP3A2 protein content of rats on days 10 and 20 (P < 0.01), and 30 (P < 0.05) compared to the control animals. Significant increases in QT and corrected QT (QTc) intervals (P < 0.01), and bradycardia (P < 0.01) without any significant effect on PR and QRS intervals were observed in DM in comparison with non-DM groups after ranolazine treatment.

CONCLUSIONS

In summary, DM induction in animals resulted in CYP 3A2 inhibition and the prolongation of QT and QTc interval as well as bradycardia after ranolazine treatment.

Biological activities of Pleurotus spp. polysaccharides: A review

Mushrooms are consumed for their nutrients and therapeutic bioactive compounds and are used medicinally in Chinese and Japanese medicine traditions since time immemorial. Members of the genus Pleurotus form a heterogeneous group of edible species with outstanding nutritional profiles rich in fiber, vitamins (thiamine, riboflavin, ascorbic acid, ergosterine, and niacin), micro and macro-elements (phosphorus and iron), and carbohydrates. Pleurotus is one of the most diversified medicinal and edible mushrooms related to the composition of chemical structures such as polysaccharides, glycoproteins, and secondary metabolites such as alkaloids and betalains. The cultivation of Pleurotus spp. on lignocellulosic wastes represents one of the most economically and cost-effective organic recycling processes, especially for the utilization of different feasible and cheap recyclable residues. Also, several Pleurotus spp. have the ability to remove phenolic compounds from wastewater with the action of phenoloxidase activity. Here, we have reviewed the chemistry of such polysaccharides and their reported biological activities, namely, anti-inflammatory, immunomodulatory, anti-diabetic, anti-tumor, antioxidant, etc. The mechanism of action and effects of novel polysaccharides extracted from various species of Pleurotus have been studied. The current study will be beneficial for guiding future research projects on the above concept and investigating more deeply the health of human beings. PRACTICAL APPLICATIONS: Mushrooms are one of the most delicious foods around the globe and have many medicinal properties for decades. Various Pleurotus species have been in focus in recent years because of their palatability and medicinal importance too. It contains many bioactive compounds among which polysaccharides are valued to a great extent. Many biological activities are exerted by polysaccharides derived from the Pleurotus spp., namely, anti-tumor, antioxidant, and many more. They are responsible for significant physiological responses in animals, animal-alternative in vitro models, and humans. Their important physicochemical characteristics benefit their use in the food industry as well. So, the biological activities of these Pleurotus spp. polysaccharides will provide an insight to develop Pleurotus spp. as functional foods, because of their nutritional value and presence of bioactive components.

Effects of ellagic acid in the testes of streptozotocin induced diabetic rats

Diabetes mellitus (DM) is a serious and common in the world health problem that leads to different complications. Changes in oxidative stress and antioxidant capacity play an important role in the pathogenesis of DM. The purpose of this study was to investigate ellagic acid (EA) treatment in diabetes induced testicular damage. In our study, 24 male Sprague Dawley rats were divided into four groups. Group 1: Control (n = 6), Group 2: EA (n = 6), Group 3: Diabet (n = 6), Group 4: Diabet + EA (n = 6). Diabetes was induced by intraperitoneal injection of streptozocin (STZ) (55 mg/kg) to group 3 and 4. EA was given 100 mg/kg/day group 2 and 4 for 35 days by oral gavage. We used that Hematoxylen-Eosin (H&E) and Johnsen's scoring to determine histological change. The terminal-deoxynucleoitidyl-transferase mediated nick end-labeling assay (TUNEL) was used for apoptosis. Oxidative stress markers were determined by qRT-PCR and immunexpression of Nrf2 was evaluated in testicular tissue. In conclusion, EA administration on the diabetes model has changed the histopathological features, apopotosis and oxidative stress marker genes in the testis and may have an effect on the reduction of diabetes induced testicular damage.

Polysaccaride-rich extract of Caesalpina ferrea stem barks attenuates mice acute inflammation induced by zymosan: Oxidative stress modulation

ETHNOPHARMACOLOGICAL RELEVANCE

Stem barks of Caesalpinia ferrea Mart. Ex Tul. (Caesalpiniaceae), also known as pau-ferro jucá or jucaína, are popularly used to treat contusions, diabetes, rheumatism and other inflammatory conditions in the form of tea, lick or decoction.

OBJECTIVE

To evaluate the effect of the polysaccharide-rich extract obtained from C. ferrea stem barks (PE-Cf) in mice models of acute inflammation induced by zymosan and the involvement of oxidative stress biomarkers.

MATERIALS AND METHODS

Mice were treated with PE-Cf (0.001, 0.01, 0.1, 1 mg/kg) by endovenous route (i.v.) or per oral (p.o.) 30 or 60 min before injection of the inflammatory stimuli zymosan (0.5 mg; intraperitoneal or subcutaneous intraplantar). The inflammatory parameters (edema, nociception, leukocyte migration) and oxidative stress markers (myeloperoxidase-MPO, malondialdehyde-MDA, nitrite, reduced glutathione-GSH, glutathione peroxidase-GPx) were evaluated in the models of paw edema (hidropletysmometry/expressed as ml or area under curve-AUC) and peritonitis (optical microscopy/expressed as n° of cells/mm³ of peritoneal fluid). Statistical analysis was performed by ANOVA, followed by Bonferroni test.

RESULTS

PE-Cf (0.1, 0.01 and 1 mg/kg) dose-dependently inhibited paw edema, showing maximal effect (74%) at 1 mg/kg in the 5th (52 ± 9.6 μl vs. zymosan: 204 ± 3.6 μl). PE-Cf (1 mg/kg) also inhibited by 43% MPO activity in the paw tissues (17 ± 1 vs. zymosan: 30 ± 2.6 U/mg). Besides, 4 h after peritonitis induction, PE-Cf (1 mg/kg) reduced neutrophil migration by 84% (432 ± 45 vs. zymosan: 2651 ± 643 cells/mm³); visceral nociception by 76% (3 ± 0.6 vs. zymosan: 16 ± 4 writhes); nitric oxide by 73% (0.131 ± 0.033 vs. zymosan: 0.578 ± 0.185 NO_2^-/NO_3^-ml); MDA (98 ± 10 vs. zymosan:156 ± 21 U/ml), and increased GSH by 65% (736 ± 65 vs. zymosan: 259 ± 58 μmol/ml) and GPx by 72% (0.037 ± 0.007 vs. zymosan: 0.010 ± 0.005 U/mg protein).

CONCLUSION

The polysaccharide-rich extract of Caesalpinia ferrea stem barks present anti-inflammatory and antioxidant effects in mice models of acute inflammation induced by zymosan.

Treatment repurposing for inflammatory bowel disease using literature-related discovery and innovation

Inflammatory bowel disease (IBD) incidence has been increasing steadily, most dramatically in the Western developed countries. Treatment often includes lifelong immunosuppressive therapy and surgery. There is a critical need to reduce the burden of IBD and to discover medical therapies with better efficacy and fewer potential side-effects. Repurposing of treatments originally studied in other diseases with similar pathogenesis is less costly and time intensive than de novo drug discovery. This study used a treatment repurposing methodology, the literature-related discovery and innovation (LRDI) text mining system, to identify potential treatments (developed for non-IBD diseases) with sufficient promise for extrapolation to treatment of IBD. By searching for desirable patterns of twenty key biomarkers relevant to IBD (e.g., inflammation, reactive oxygen species, autophagy, barrier function), the LRDI-based query retrieved approximately 9500 records from Medline. The most recent 350 records were further analyzed for proof-of-concept. Approximately 18% (64/350) met the criteria for discovery (not previously studied in IBD human or animal models) and relevance for application to IBD treatment. Many of the treatments were compounds derived from herbal remedies, and the majority of treatments were being studied in cancer, diabetes, and central nervous system disease, such as depression and dementia. As further validation of the search strategy, the query identified ten treatments that have just recently begun testing in IBD models in the last three years. Literature-related discovery and innovation text mining contains a unique search strategy with tremendous potential to identify treatments for repurposing. A more comprehensive query with additional key biomarkers would have retrieved many thousands more records, further increasing the yield of IBD treatment repurposing discovery.

Therapeutic Effects of 5,7-Dihydroxy-6-Oxoheptadecanoic Acid on Dysglycemia, Dyslipidemia, and Other Complications in Diabetic Rats

The current study aimed to investigate the therapeutic effects of 5,7-dihydroxy-6-oxoheptadecanoic acid (DHA) from Tiliacora triandra on rat models of type 2 diabetes mellitus (T2DM). T2DM was induced with a combination of high-fat diet/streptozotocin (HFD/STZ), and diabetic rats were treated with DHA (25 mg/kg) for 30 days. The body weight, fasting blood glucose (FBG), serum, and liver biochemical parameters, as well as histological evaluations of the liver and pancreas, were evaluated. Diabetic rats displayed a significant increase in FBG, serum lipid profiles (triglycerides, total cholesterol, and low-density lipoprotein cholesterol), liver function enzymes (aspartate transaminase, alkaline phosphatase, and alanine transaminase), creatinine, liver malondialdehyde (MDA), and myeloperoxidase (MPO) contents. Furthermore, insulin level and liver antioxidant enzyme activities (catalase [CAT], superoxide dismutase [SOD], and glutathione peroxidase [GSH-Px]) were significantly reduced in the diabetic rats. Whereas, treatment with DHA significantly reduced FBG, serum lipids, liver function enzymes, serum creatinine, liver MDA, and MPO contents. In addition, treatment with DHA significantly increased serum insulin level and liver SOD, CAT, and GSH-Px activities. In addition, DHA alleviated histopathological changes in the pancreas and liver caused by T2DM. These results portray the antidiabetic and antioxidative properties of DHA and can be considered as a potential treatment for T2DM.

Peanut skin extract ameliorates the symptoms of type 2 diabetes mellitus in mice by alleviating inflammation and maintaining gut microbiota homeostasis

In this study, mice with type 2 diabetes mellitus (T2DM) induced by high-fat diet were used to investigate the antidiabetic effect and mechanism of action of peanut skin extract (PSE). Results revealed that the fasting blood glucose, body weight, and food intake of mice with T2DM significantly decreased after they were given PSE. The effects of 80 mg/kg PSE were similar to those of 140 mg/kg metformin (MET). The glucose tolerance and insulin sensitivity of the mice also improved. The composition of intestinal microflora in the mice significantly changed after PSE administration. In particular, no Actinobacteria was detected in the PSE-treated group, and the ratio of Firmicutes to Bacteroidetes was remarkably reduced. PSE also increased the abundance of gut microbiota involved in fatty acid biosynthesis, lipid biosynthesis, and sucrose metabolism. The abundance of gut microbiota related to aminoacyl-tRNA biosynthesis also decreased. Lipopolysaccharide, interleukin (IL)-6, IL-1β and tumor necrosis factor-α in the blood, liver and adipose tissue were reduced by PSE. Similarly, the mRNA expression levels of IkappaB kinase and nuclear factor kappaB in the hypothalamus were reduced by PSE. These results suggested that PSE and MET elicited significant antidiabetic effects by maintaining gut microbiota and inhibiting inflammation.

Bioassay-Guided Fractionation, Chemical Compositions and Antibacterial Activity of Extracts from Rhizomes of Globba schomburgkii Hook.f

Bioassay-guided fractionation was conducted on dichloromethane extract from the rhizomes of Globba schomburgkii Hook.f., which have previously been reported as the part with the highest antibacterial activity. 10 fractions and 20 sub-fractions were obtained and evaluated for their potency against various strains of bacteria. The most active sub-fractions were 8 times more effective against Staphylococcus aureus and Micrococcus luteus than the original crude extract. Moreover, two pure compounds, namely petasol and (E)-15,16-dinorlabda-8(17),11-dien-13-one, were successfully isolated and characterized for the first time from this plant species. Untargeted compound analysis of all fractions and sub-fractions was performed by gas chromatography hyphenated with mass spectrometry, leading to positive identification of 167 compounds according to comparison with the mass spectrum and retention index database, 137 of which have never been reported for G. schomburgkii. The correlation between antibacterial activity and composition of each fraction suggests that the bioactive compounds could be 4,8-β-epoxycaryophyllene, methyl isocostate, (E)-labda-8(17),12-diene-15,16-dial, α-kessyl acetate, zederone, clovanediol, ledene oxide-(I), alantolactone, or 8α,11-elemadiol.