Prevention and current onset delay approaches of type 2 diabetes mellitus (T2DM)

Natural Compounds as DPP-4 Inhibitors: 3D-Similarity Search, ADME Toxicity, and Molecular Docking Approaches

Type 2 diabetes mellitus is one of the most common diseases of the 21st century, caused by a sedentary lifestyle, poor diet, high blood pressure, family history, and obesity. To date, there are no known complete cures for type 2 diabetes. To identify bioactive natural products (NPs) to manage type 2 diabetes, the NPs from the ZINC15 database (ZINC-NPs DB) were screened using a 3D shape similarity search, molecular docking approaches, and ADMETox approaches. Frequently, in silico studies result in asymmetric structures as “hit” molecules. Therefore, the asymmetrical FDA-approved diabetes drugs linagliptin (8-[(3R)-3-aminopiperidin-1-yl]-7-but-2-ynyl-3-methyl-1-[(4-methylquinazolin-2-yl)methyl]purine-2,6-dione), sitagliptin ((3R)-3-amino-1-[3-(trifluoromethyl)-6,8-dihydro-5H-[1,2,4]triazolo[4,3-a]pyrazin-7-yl]-4-(2,4,5-trifluorophenyl)butan-1-one), and alogliptin (2-[[6-[(3R)-3-aminopiperidin-1-yl]-3-methyl-2,4-dioxopyrimidin-1-yl]methyl]benzonitrile) were used as queries to virtually screen the ZINC-NPs DB and detect novel potential dipeptidyl peptidase-4 (DPP-4) inhibitors. The most promising NPs, characterized by the best sets of similarity and ADMETox features, were used during the molecular docking stage. The results highlight that 11 asymmetrical NPs out of 224,205 NPs are potential DPP-4 candidates from natural sources and deserve consideration for further in vitro/in vivo tests.

Biomedical Potential of Plant-Based Selenium Nanoparticles: A Comprehensive Review on Therapeutic and Mechanistic Aspects

Selenium nanoparticles (SeNPs) have advantages over other nanomaterials because of the promising role of selenium in the stabilization of the immune system and activation of the defense response. The use of SeNPs and their supplements not only have pharmacological significance but also boost and prepare the body's immune system to fight the pathogens. This review summarizes the recent progress in the biogenesis of plant-based SeNPs by using various plant species and the role of secondary metabolites on their biocompatible functioning. Phyto-synthesis of SeNPs results in the synthesis of nanomaterials of various, size, shape and biochemical nature and has advantages over other routine physical and chemical methods because of their biocompatibility, eco-friendly nature and in vivo actions. Unfortunately, the plant-based SeNPs failed to attain considerable attention in the pharmaceutical industry. However, a few studies were performed to explore the therapeutic potential of the SeNPs against various cancer cells, microbial pathogens, viral infections, hepatoprotective actions, diabetic management, and antioxidant approaches. Further, some of the selenium-based drug delivery systems are developed by engineering the SeNPs with the functional ligands to deliver drugs to the targeted sites. This review also provides up-to-date information on the mechanistic actions that the SeNPs adopt to achieve their designated tasks as it may help to develop precision medicine with customized treatment and healthcare for the ailing population.

Natural products in diabetes research: quantitative literature analysis

The current study aimed to identify which natural products and which research directions are related to the major contributors to academic journals for diabetes therapy. Bibliometric data were extracted from the Web of Science online database using the search string TOPIC = (''natural product*' OR ''natural compound*' OR ''natural molecule*' OR 'phytochemical*' OR ''secondary metabolite*') AND TS = ('diabet*') and analysed by a bibliometric software, VOSviewer. The search yielded 3694 publications, which were collectively cited 80,791 times, with an H-index of 117 and 21.9 citations per publication on average. The top-contributing countries were India, the USA, China, South Korea and Brazil. Curcumin, flavanone, resveratrol, carotenoid, polyphenols, flavonol, flavone and berberine were the most frequently cited natural products or compound classes. Our results provide a brief overview of the major directions of natural product research in diabetes up to now and hint on promising avenues for future research.

Incidence and risk factors of type 2 diabetes mellitus in an overweight and obese population: a long-term retrospective cohort study from a Gulf state

OBJECTIVES

A high body mass index (BMI) is associated with risk of type 2 diabetes mellitus (DM). The United Arab Emirates (UAE) is experiencing a marked increase in obesity. Nonetheless, no data are available regarding the incidence of type 2 DM in the high-risk adult UAE population. Therefore, this study aimed to evaluate the incidence rate and risk of developing type 2 DM among individuals with above-normal BMI in the UAE.

DESIGN

A retrospective cohort study.

SETTING

Outpatient clinics at a tertiary care centre in Al Ain, UAE.

PARTICIPANTS

Three hundred and sixty-two overweight or obese adult UAE nationals who visited outpatient clinics between April 2008 and December 2008.

PRIMARY OUTCOME MEASURE

Patients with type 2 DM were identified based on diagnosis established by a physician or through glycated haemoglobin (HbA1c) levels ≥6.5% during the follow-up period (until April 2018).

RESULTS

The overall incidence rate of type 2 DM during the median follow-up time of 8.7 years was 16.3 (95% CI 12.1 to 21.4) cases per 1000 person-years. Incidence rates in men and women were 17.7 (95% CI 11.6 to 25.9) and 15.0 (95% CI 9.8 to 22.2) cases per 1000 person-years, respectively. Multivariable Cox proportional hazard analysis determined older age and obesity in women and pre-diabetes in men to be independent risk factors for developing type 2 DM.

CONCLUSIONS

The incidence rate of type 2 DM in overweight and obese UAE nationals is high. In addition to screening, current strategies should strongly emphasise lifestyle modifications to decrease HbA1c and BMI levels in this high-risk population.

Twenty-year trends in the prescription costs of Type 2 diabetes: Real world data and empirical analysis in Greece

AIMS

To estimate and compare the prescription costs for the management of patients with diabetes over a period of 20 years in Greece, based on real world data.

METHODS

The records of outpatients with T2D, monitored at three diabetes centres, were examined in four cross-sections (1998, 2006, 2012, 2018). Prescribed medicines per patient, along with a set of clinical indicators were recorded. Annual costs of pharmaceutical treatment per patient were calculated by using each year's nominal retail prices, as well as by adjusting for 2018 price levels, in order to account for price differences over time.

RESULTS

4066 patients were included in the analysis. Prescription patterns indicate a quick uptake of the new classes of glucose-lowering drugs and a reduction in the proportional use of sulfonylurea and glitazone. Adjusting for 2018 prices, the average total annual prescription cost per patient was 381.54 Euros (s.d. 297.44) in 1998 and 1147.21 Euros (s.d. 814.39) in 2018. Glucose-lowering drug costs per patient increase from 1998 onwards, whereas the costs of antihypertensive, antiplatelet and lipid-lowering treatment declined gradually, especially after 2006.

CONCLUSIONS

Per patient prescription costs for glucose-lowering drugs present a steep increase, in Greece over the last 20 years. Real-world evidence studies that compare this increase with the changes in patient outcomes are essential in order to examine whether a costs-vs-outcomes balance is optimal.

Sucupira Oil-Loaded Nanostructured Lipid Carriers (NLC): Lipid Screening, Factorial Design, Release Profile, and Cytotoxicity

Essential oils are odorant liquid oily products consisting of a complex mixture of volatile compounds obtained from a plant raw material. They have been increasingly proven to act as potential natural agents in the treatment of several human conditions, including diabetes mellitus (DM). DM is a metabolic disorder characterized by chronic hyperglycemia closely related to carbohydrate, protein and fat metabolism disturbances. In order to explore novel approaches for the management of DM our group proposes the encapsulation of sucupira essential oil, obtained from the fruits of the Brazilian plants of the genus Pterodon, in nanostructured lipid carriers (NLCs), a second generation of lipid nanoparticles which act as new controlled drug delivery system (DDS). Encapsulation was performed by hot high-pressure homogenization (HPH) technique and the samples were then analyzed by dynamic light scattering (DLS) for mean average size and polydispersity index (PI) and by electrophoretic light scattering (ELS) for zeta potential (ZP), immediately after production and after 24 h of storage at 4 °C. An optimal sucupira-loaded NLC was found to consist of 0.5% (m/V) sucupira oil, 4.5% (m/V) of Kollivax^® GMS II and 1.425% (m/V) of TPGS (formulation no. 6) characterized by a mean particle size ranging from 148.1 ± 0.9815 nm (0 h) to 159.3 ± 9.539 nm (at 24 h), a PI from 0.274 ± 0.029 (0 h) to 0.305 ± 0.028 (24 h) and a ZP from −0.00236 ± 0.147 mV (at 0 h) to 0.125 ± 0.162 (at 24 h). The encapsulation efficiency and loading capacity were 99.98% and 9.6%, respectively. The optimized formulation followed a modified release profile fitting the first order kinetics, over a period of 8 h. In vitro cytotoxicity studies were performed against Caco-2 cell lines, for which the cell viability above 90% confirmed the non-cytotoxic profile of both blank and sucupira oil-loaded NLC.

Nanoparticle Delivery Systems in the Treatment of Diabetes Complications

Diabetes mellitus, an incurable metabolic disease, is characterized by changes in the homeostasis of blood sugar levels, being the subcutaneous injection of insulin the first line treatment. This administration route is however associated with limited patient's compliance, due to the risk of pain, discomfort and local infection. Nanoparticles have been proposed as insulin carriers to make possible the administration of the peptide via friendlier pathways without the need of injection, i.e., via oral or nasal routes. Nanoparticles stand for particles in the nanometer range that can be obtained from different materials (e.g., polysaccharides, synthetic polymers, lipid) and are commonly used with the aim to improve the physicochemical stability of the loaded drug and thereby its bioavailability. This review discusses the use of different types of nanoparticles (e.g., polymeric and lipid nanoparticles, liposomes, dendrimers, niosomes, micelles, nanoemulsions and also drug nanosuspensions) for improved delivery of different oral hypoglycemic agents in comparison to conventional therapies.

Sugar-Lowering Drugs for Type 2 Diabetes Mellitus and Metabolic Syndrome-Review of Classical and New Compounds: Part-I

Diabetes mellitus (DM) is a metabolic disorder characterized by chronic hyperglycemia together with disturbances in the metabolism of carbohydrates, proteins and fat, which in general results from an insulin availability and need imbalance. In a great number of patients, marketed anti-glycemic agents have shown poor effectiveness in maintaining a long-term glycemic control, thus being associated with severe adverse effects and leading to an emerging interest in natural compounds (e.g., essential oils and other secondary plant metabolites, namely, flavonoid-rich compounds) as a novel approach for prevention, management and/or treatment of either non-insulin-dependent diabetes mellitus (T2DM, type 2 DM) and/or Metabolic Syndrome (MS). In this review, some of these promising glucose-lowering agents will be comprehensively discussed.

Sugar-Lowering Drugs for Type 2 Diabetes Mellitus and Metabolic Syndrome-Strategies for In Vivo Administration: Part-II

Diabetes is a complex disease characterized by hyperglycemia, together with polyuria, polydipsia, and polyphagia. While Type 1 diabetes mellitus (T1DM) results from genetic, environmental, or immune dysfunction factors leading to pancreatic β-cell destruction depriving the organism from endogenous insulin, Type 2 diabetes mellitus (T2DM) is characterized by peripheral insulin resistance. Depending on the type of diabetes mellitus and drug mechanism to study, the animal model should be carefully selected among the wide variety of the currently available ones. This review discusses the most common animal models currently employed to study T1DM and T2DM. Moreover, an overview on the administration routes that could be used is also discussed.

Efficacy and adverse reaction to different doses of atorvastatin in the treatment of type II diabetes mellitus

Background: Type II diabetes mellitus (T2DM), a persistent metabolic disorder, is primarily characterized by insulin resistance, relative insulin deficiency and dyslipidemia. Here, we aimed to investigate whether different doses of atorvastatin (ATV) affect rats with T2DM. A total of 110 Sprague–Dawley rats were successfully established as T2DM models. Methods: First, the total cholesterol, triglyceride (TG), high-/low-/very-low-density lipoprotein cholesterol (HDL-c/LDL-c/VLDL-c), alanine transaminase (ALT), aspartate aminotransferase (AST), blood urea nitrogen (BUN), creatinine (Cr), apolipoprotein Al (ApoA1) and apolipoprotein B (ApoB) levels in rat serum were analyzed. In addition, cholesteryl ester transfer protein (CETP) and retinol-binding protein 4 (RBP4) were also measured. Then, the incidence of adverse reactions was noted. Finally, the pathological study of liver and pancreatic tissues was performed. Results: Rats administered ATV at the doses of 40 and 80 mg/(kg·day) showed down-regulated TG, LDL-c, ApoB, CETP and RBP4 levels yet up-regulated HDL-c and ApoAl levels. Rats administered ATV at a dose of 80 mg/(kg·day) exhibited a higher incidence of adverse reactions and higher ALT and AST levels but lower BUN and Cr levels, which might affect liver and kidney function. Rats administered ATV at the doses of 40 and 80 mg/(kg·day) demonstrated significantly improved liver injury and pancreatic injury induced by T2DM. Conclusion: These data revealed that ATV could improve the lipid metabolism in T2DM rats and 40 mg/(kg·day) may serve as the optimal dose for the reduction of lipid levels and the incidence of adverse effects.

Action of corilagin on hyperglycemia, hyperlipidemia and oxidative stress in streptozotocin-induced diabetic rats

Diabetes mellitus is the world's most common endocrine disease involving metabolic disorders of carbohydrate, protein and fat. This study was undertaken to investigate the anti-diabetic activity of corilagin, a member of polyphenolic tannins used against hyperglycemia and many other diseases in well-known animal models. Diabetes was induced chemically by intraperitoneal administration of Streptozotocin (40 mg/kg bw) to albino Wistar rats. Diabetic rats showed significant increase in the levels of fasting blood glucose, glycated haemoglobin, total cholesterol, triglyceride, low density lipoprotein cholesterol, very low density lipoprotein cholesterol, and a significant decrease in the level of body weight, plasma insulin, high density lipoprotein cholesterol, antioxidant activities, viz. superoxide dismutase, catalase and reduced glutathione when compared to controls. However, after 30 days of oral administration of corilagin (10 and 20 mg/kg bw/day) to these diabetic rats evoked significant alterations in the above mentioned parameters. The effect of corilagin was compared with the standard drug, glibenclamide (0.1 mg/kg body weight/day). Thus, the present study suggests that the corilagin acts as a natural, effective therapeutic agent to regulate diabetes, by exhibiting antidiabetic, antihyperlipidemic and antioxidant properties in STZ induced diabetic rats.

Patterns of glucose lowering drugs utilization in Portugal and in the Netherlands. Trends over time

AIMS

To compare the temporal trends in the consumption patterns of glucose lowering drugs (GLD) between Portugal and the Netherlands from 2004 to 2013 and to examine possible reasons behind the cross-national variation found.

METHODS

All GLD (ATC pharmacological subgroup A10B) were selected for analysis. Consumption data were obtained for the 10-year period. Portuguese and Dutch drug estimates were obtained from nationwide databases.

RESULTS

The consumption of GLD increased in Portugal from 52.9 defined daily dose per 1000 inhabitants per day (DHD) in 2004 to 70.0 DHD in 2013 and in the Netherlands from 44.9 DHD in 2004 to 50.7 DHD in 2013. In Portugal, the use of fixed-dose combinations, especially with dipeptidyl peptidase-4 inhibitors (DPP-4) increased remarkably and in 2013 represented almost a quarter of total GLD consumption. In the Netherlands, the use of combinations was residual.

CONCLUSIONS

The consumption of GLD rose over the 10-year period in both countries. However, Portuguese overall consumption and costs of GLD were higher. The differentially rapid uptake of DPP-4 inhibitors in Portugal was the main driver of the cost difference.

Pigment epithelium-derived factor increases in type 2 diabetes after treatment with metformin

OBJECTIVE

Pigment epithelium-derived factor (PEDF) has anti-angiogenic, immunomodulatory and anti-inflammatory properties. In addition to the significant role it plays in reducing diabetic complications, PEDF is now used in the treatment of certain cancers. It possibly plays a role in insulin resistance cases, too. However, whether metformin treatment has any significant effects on PEDF levels is not known. In this study, we investigated the regulation of PEDF in type 2 diabetes in relation to fat mass and insulin resistance before and after the use of metformin for treatment.

DESIGN

Prospective cohort study.

SUBJECTS

Thirty-six patients with newly diagnosed type 2 diabetes and 33 healthy individuals.

MEASUREMENTS

Baseline weight, waist circumference (WC), fasting (FPG) and postprandial (PPPG) glucose, insulin, HbA1c, HOMA, PEDF and total/truncal fat mass were determined both in the diabetic and control subjects. Procedures were repeated in the diabetic group after a 6-month metformin treatment.

RESULTS

Baseline FPG, PPPG, HbA1c, HOMA, weight, WC and truncal fat mass were higher in patients with diabetes whereas PEDF levels were found to be comparable with the controls. We completed the study with 31 of the 36 patients with diabetes we had selected for the study. We observed a decrease in the weight, WC, FPG, PPPG, HOMA, total and truncal fat mass of the patients while there was a significant rise in the PEDF levels (P = 0·002) after the metformin treatment. On the other hand, no significant correlation was observed between the change in PEDF levels and the clinical and laboratory findings.

CONCLUSION

Our study is the first to identify a metformin-related increase in PEDF levels in diabetes. The increase observed in PEDF levels after the metformin treatment does not seem to be related to the changes in insulin resistance, fat mass or glycemic control. Hence, our results suggest that further investigation is necessary to determine the direct effects of metformin on PEDF gene and protein expression in vitro.

Short and long-term effects of Baccharis articulata on glucose homeostasis

In this study, the in vivo effect of the crude extract and n-butanol and aqueous residual fractions of Baccharis articulata (Lam.) Pers. on serum glucose levels, insulin secretion and liver and muscle glycogen content, as well as in vitro action on serum intestinal disaccharidase activity and albumin glycation were investigated. Oral administration of the extract and fractions reduced glycemia in hyperglycemic rats. Additionally, the n-butanol fraction, which has high flavonoids content, stimulated insulin secretion, exhibiting an insulinogenic index similar to that of glipizide. Also, the n-butanol fraction treatment significantly increased glycogen content in both liver and muscle tissue. In vitro incubation with the crude extract and n-butanol and aqueous residual fractions inhibited maltase activity and the formation of advanced glycation end-products (AGEs). Thus, the results demonstrated that B. articulata exhibits a significant antihyperglycemic and insulin-secretagogue role. These effects on the regulation of glucose homeostasis observed for B. articulata indicate potential anti-diabetic properties.

Effect of zinc supplementation on type 2 diabetes parameters and liver metallothionein expressions in Wistar rats

Zinc is a trace metal and acts as an active component of various enzymes. Zinc deficiency has been suggested to be associated with the development of diabetes. The present study investigated the role of zinc supplementation on prevention of diabetic conditions. A double-disease model mimicking hyperlipidemia and type 2 diabetes was created by applying high-fat diet and streptozotocin (STZ) to Wistar rats. We demonstrated that zinc supplementation improved symptoms of diabetes such as polydipsia and increased serum level of high-density lipoprotein cholesterol, indicating that zinc supplementation has a potential beneficial effect on diabetic conditions. The level of maldondialdehyde (MDA), an oxidative stress marker, was reduced in liver by zinc supplementation in high fat-fed rats with or without STZ injection. Meanwhile, we observed an increase in the expression of metallothioneins (MTs) in liver of rats treated with zinc. This suggests that the induction of MTs in liver, which has been shown to be important in scavenging free radicals, could be one of the underlying mechanisms of zinc supplementation on reducing MDA levels in liver. Finally, we found that zinc levels in liver were increased while there was no change in serum zinc levels, indicating that local zinc level might be a critical factor for the induction of MTs. Also, the level of MTs could potentially be an index of zinc bioavailability. Taken together, these results suggest that both zinc and MT could play an important role in balancing nutrition and metabolism to prevent diabetic development.