In vitro evaluation of 5-arylidene-2-thioxo-4-thiazolidinones active as aldose reductase inhibitors

Development of new thiazolidine-2,4-dione hybrids as aldose reductase inhibitors endowed with antihyperglycaemic activity: design, synthesis, biological investigations, and in silico insights

This research study describes the development of new small molecules based on 2,4-thiazolidinedione (2,4-TZD) and their aldose reductase (AR) inhibitory activities. The synthesis of 17 new derivatives of 2,4-TZDs hybrids was feasible by incorporating two known bioactive scaffolds, benzothiazole heterocycle, and nitro phenacyl moiety. The most active hybrid (8b) was found to inhibit AR in a non-competitive manner (0.16 µM), as confirmed by kinetic studies and molecular docking simulations. Furthermore, the in vivo experiments demonstrated that compound 8b had a significant hypoglycaemic effect in mice with hyperglycaemia induced by streptozotocin. Fifty milligrams per kilogram dose of 8b produced a marked decrease in blood glucose concentration, and a lower dose of 5 mg/kg demonstrated a noticeable antihyperglycaemic effect. These outcomes suggested that compound 8b may be used as a promising therapeutic agent for the treatment of diabetic complications.

Synthesis of 5-arylidenerhodanines in L-proline-based deep eutectic solvent

Rhodanines and their derivatives are known to have many pharmacological activities that can be modulated through different functionalization sites. One of the most studied modification in those scaffolds is the introduction of a benzylidene moiety on C5 via a Knoevenagel reaction. Here, a facile synthesis of 5-arylidenerhodanines via a Knoevenagel reaction in an ʟ-proline-based deep eutectic solvent (DES) is reported. This method is fast (1 h at 60 °C), easy, catalyst-free and sustainable as no classical organic solvents were used. The expected compounds are recovered by a simple filtration after hydrolysis and no purification is required. Those derivatives were studied for their antioxidant activities and the results are consistent with those reported in the literature indicating that phenolic compounds are the more active ones.

Designed multiple ligands for the treatment of type 2 diabetes mellitus and its complications: Discovery of (5-arylidene-4-oxo-2-thioxothiazolidin-3-yl)alkanoic acids active as novel dual-targeted PTP1B/AKR1B1 inhibitors

Type 2 diabetes mellitus (T2DM) is a serious chronic disease with an alarmingly growing worldwide prevalence. Current treatment of T2DM mainly relies on drug combinations in order to control blood glucose levels and consequently prevent the onset of hyperglycaemia-related complications. The development of multiple-targeted drugs recently emerged as an attractive alternative to drug combinations for the treatment of complex diseases with multifactorial pathogenesis, such as T2DM. Protein tyrosine phosphatase 1B (PTP1B) and aldose reductase (AKR1B1) are two enzymes crucially involved in the development of T2DM and its chronic complications and, therefore, dual inhibitors targeted to both these enzymes could provide novel agents for the treatment of this complex pathological condition. In continuing our search for dual-targeted PTP1B/AKR1B1 inhibitors, we designed new (5-arylidene-4-oxo-2-thioxothiazolidin-3-yl)alkanoic acids. Among them, 3-(4-phenylbutoxy)benzylidene derivatives 6f and 7f, endowed with interesting inhibitory activity against both targets, proved to control specific cellular pathways implicated in the development of T2DM and related complications.

Synthesis, antimycobacterial, cytotoxicity, anti-inflammatory, in silico studies and molecular dynamics of pyrazole-embedded thiazolidin-4-one hybrids

In the present investigation, we devolved and synthesized a new series of pyrazole-embedded thiazolidin-4-one derivatives (9a-p) with the goal to produce promising antitubercular leads. The in vitro antimycobacterial activity of the synthesized compounds was tested against replicating and nonreplicating Mtb H37Rv strains. With MIC ranging from 3.03 to 22.55 µg/ml, five compounds (9a, 9c, 9d, 9e, and 9f) emerged as promising antitubercular agents. The active molecules were nontoxic to normal Vero cells. All the synthesized compounds were evaluated for in vitro anti-inflammatory studies. Compounds 9a, 9b, 9c, 9h, and 9i exhibited excellent anti-inflammatory efficacy. Docking study was performed to understand the binding pattern of the significantly active compound 9a with 1P44.

CADD Studies in the Discovery of Potential ARI (Aldose Reductase Inhibitors) Agents for the Treatment of Diabetic Complications

The lack of currently available drugs for treating diabetes complications has stimulated our interest in finding new Aldose Reductase inhibitors (ARIs) with more beneficial biological properties. One metabolic method uses aldose reductase inhibitors in the first step of the polyol pathway to control excess glucose flux in diabetic tissues. Computer-aided drug discovery (CADD) is key in finding and optimizing potential lead substances. AR inhibitors (ARI) have been widely discussed in the literature. For example, Epalrestat is currently the only ARI used to treat patients with diabetic neuropathy in Japan, India, and China. Inhibiting R in patients with severe to moderate diabetic autonomic neuropathy benefits heart rate variability. AT-001, an AR inhibitor, is now being tested in COVID-19 to see how safe and effective it reduces inflammation and cardiac damage. In summary, these results from animal and human studies strongly indicate that AR can cause cardiovascular complications in diabetes. The current multi-center, large-scale randomized human study of the newly developed powerful ARI may prove its role in diabetic cardiovascular disease to establish therapeutic potential. During the recent coronavirus disease (COVID-19) outbreak in 2019, diabetes and cardiovascular disease were risk factors for severely negative clinical outcomes in patients with COVID19. New data shows that diabetes and obesity are among the strongest predictors of COVID-19 hospitalization. Patients and risk factors for severe morbidity and mortality of COVID- 19.

Linearolactone Induces Necrotic-like Death in Giardia intestinalis Trophozoites: Prediction of a Likely Target

Linearolactone (LL) is a neo-clerodane type diterpene that has been shown to exert giardicidal effects; however, its mechanism of action is unknown. This work analyzes the cytotoxic effect of LL on Giardia intestinalis trophozoites and identifies proteins that could be targeted by this active natural product. Increasing concentrations of LL and albendazole (ABZ) were used as test and reference drugs, respectively. Cell cycle progression, determination of reactive oxygen species (ROS) and apoptosis/necrosis events were evaluated by flow cytometry (FCM). Ultrastructural alterations were analyzed by transmission electron microscopy (TEM). Ligand–protein docking analyses were carried out using the LL structure raised from a drug library and the crystal structure of an aldose reductase homologue (GdAldRed) from G. intestinalis. LL induced partial arrest at the S phase of trophozoite cell cycle without evidence of ROS production. LL induced pronecrotic death in addition to inducing ultrastructural alterations as changes in vacuole abundances, appearance of perinuclear and periplasmic spaces, and deposition of glycogen granules. On the other hand, the in silico study predicted that GdAldRed is a likely target of LL because it showed a favored change in Gibbs free energy for this complex.

Syntheses, in vitro, and in silico studies of rhodanine-based schiff bases as potential α-amylase inhibitors and radicals (DPPH and ABTS) scavengers

A two-step reaction method was used to synthesize a series of rhodanine-based Schiff bases (2-33) that were characterized using spectroscopic techniques. All compounds were assessed for α-amylase inhibitory and radical scavenging (DPPH and ABTS) activities. In comparison to the standard acarbose (IC₅₀ = 9.08 ± 0.07 µM), all compounds demonstrated good to moderate α-amylase inhibitory activity (IC₅₀ = 10.91 ± 0.08-61.89 ± 0.102 µM). Compounds also demonstrated significantly higher DPPH (IC₅₀ = 10.33 ± 0.02-96.65 ± 0.03 µM) and ABTS (IC₅₀ = 12.01 ± 0.12-97.47 ± 0.13 µM) radical scavenging activities than ascorbic acid (DPPH, IC₅₀ = 15.08 ± 0.03 µM; ABTS, IC₅₀ = 16.09 ± 0.17 µM). The limited structure-activity relationship (SAR) suggests that the position and nature of the substituted groups on the phenyl ring have a vital role in varying inhibitory potential. Among the series, compounds with an electron-withdrawing group at the para position showed the highest potency. Kinetic studies revealed that the compounds followed a competitive mode of inhibition. Molecular docking results are found to agree with experimental findings, showing that compounds reside in the active pocket due to the main rhodanine moiety.

Non-acidic bifunctional benzothiazole-based thiazolidinones with antimicrobial and aldose reductase inhibitory activity as a promising therapeutic strategy for sepsis

Sepsis is a life-threatening disease that affects millions of people worldwide. Microbial infections that lead to sepsis syndrome are associated with an increased production of inflammatory molecules. Aldose reductase has recently emerged as a molecular target that is involved in various inflammatory diseases, including sepsis. Herein, a series of previously synthesized benzothiazole-based thiazolidinones that exhibited strong antibacterial and antifungal activities has been evaluated for inhibition efficacy against aldose reductase and selectivity toward aldehyde reductase under in vitro conditions. The most promising inhibitor 5 was characterized with IC₅₀ value of 3.99 μM and a moderate selectivity. Molecular docking simulations revealed the binding mode of compounds at the active site of human aldose reductase. Moreover, owning to the absence of an acidic pharmacophore, good membrane permeation of the novel aldose reductase inhibitors was predicted. Excellent “drug-likeness” was assessed for most of the compounds by applying the criteria of Lipinski’s “rule of five”.

The Importance of Rhodanine Scaffold in Medicinal Chemistry: A Comprehensive Overview

After the clinical use of epalrestat that contains a rhodanine ring, in type II diabetes mellitus and diabetic complications, rhodanin-based compounds have become an important class of heterocyclic in the field of medicinal chemistry. Various modifications to the rhodanine ring have led to a broad spectrum of biological activity of these compounds. Synthesis of rhodanine derivatives, depended on advenced throughput scanning hits, frequently causes potent and selective modulators of targeted enzymes or receptors, which apply their pharmacological activities through different mechanisms of action. Rhodanine-based compounds will likely stay a privileged scaffold in drug discovery because of different probability of chemical modifications of the rhodanine ring. We have, therefore reviewed their biological activities and structure activity relationship.

Identification of a new class of potent aldose reductase inhibitors: Design, microwave-assisted synthesis, in vitro and in silico evaluation of 2-pyrazolines

Aldose reductase (AR) acts as a multi-disease target for the design and development of therapeutic agents for the management of diabetic complications as well as non-diabetic diseases. In the search for potent AR inhibitors, the microwave-assisted synthesis of twenty new compounds with a 1,3-diaryl-5-(4-fluorophenyl)-2-pyrazoline moiety as a common fragment in their structure (1-20) was carried out efficiently. Compounds 1-20 were subjected to in vitro studies, which were conducted to assess their AR inhibitory effects and cytotoxicity towards L929 mouse fibroblast (normal) cells. Among these compounds, 1-(3-bromophenyl)-3-(4-piperidinophenyl)-5-(4-fluorophenyl)-2-pyrazoline (20) was identified as the most promising AR inhibitor with an IC₅₀ value of 0.160 ± 0.005 μM exerting competitive inhibition with a K_i value of 0.019 ± 0.001 μM as compared to epalrestat (IC₅₀ = 0.279 ± 0.001 μM; K_i = 0.801 ± 0.023 μM) and quercetin (IC₅₀ = 4.120 ± 0.123 μM; K_i = 6.082 ± 0.272 μM). Compound 20 displayed cytotoxicity towards L929 cells with an IC₅₀ value of 18.75 ± 1.06 μM highlighting its safety as an AR inhibitor. Molecular docking studies suggested that π-π stacking interactions occurred between the m-bromophenyl moiety of compound 20 and Trp21. Based on in silico pharmacokinetic studies, compound 20 was found to possess favorable oral bioavailability and drug-like properties. It can be concluded that compound 20 is a potential orally bioavailable AR inhibitor for the management of diabetic complications as well as non-diabetic diseases.

Designed Synthesis of Diversely Substituted Hydantoins and Hydantoin-Based Hybrid Molecules: A Personal Account

Hydantoin and its analogues such as thiohydantoin and iminohydantoin have received substantial attention from both a chemical and a biological point of view. Several compounds of this class have shown useful pharmacological activities such as anticonvulsant, antitumor, antiarrhythmic, and herbicidal properties that have led, in some cases, to clinical applications. Because of these broad-spectrum activities, intensive research efforts have been dedicated in industry and academia to the synthesis and structural modifications of hydantoin and its derivatives. Realizing the importance of hydantoin in organic and medicinal chemistry, we also initiated a research program that successfully designed and developed new routes and methods for the formation of hydantoin, thiohydantoin, and iminohydantoin substituted at various positions, particularly at the N-1 position without following a protection–deprotection strategy. Because combinations of two or more pharmacophoric groups can lead to hybrid molecules that display a mixed mechanism of action on biological targets, we extended our developed strategy to the syntheses of new types of hydantoin-based hybrid molecules by combining hydantoin with a triazole, isoxazoline, or phosphate scaffold as a second pharmacophore to exploit their diverse biological functions.

1 Introduction

2 Chemistry and Properties

2.1 Physical Properties

2.2 Chemical Properties

2.3 Biological Properties

3 General Synthetic Methods

4 Synthesis of Diversely Substituted Hydantoins

5 Synthesis of Diversely Substituted Thiohydantoins

6 Synthesis of Diversely Substituted Iminohydantoins

7 Fused or Bicyclic (Thio)hydantoins

8 Di- or Multivalent (Thio)hydantoins

9 Hydantoin-Based Hybrid Molecules

9.1 Hydantoin–Isooxazoline Hybrids

9.2 Hydantoin–Triazole Hybrids

9.3 Hydantoin–Phosphate Hybrids: Phosphorylated Hydantoins

10 Summary and Outlook

A new series of 2,4-thiazolidinediones endowed with potent aldose reductase inhibitory activity

In an effort to identify potent aldose reductase (AR) inhibitors, 5-(arylidene)thiazolidine-2,4-diones (1–8), which were prepared by the solvent-free reaction of 2,4-thiazolidinedione with aromatic aldehydes in the presence of urea, were examined for their in vitro AR inhibitory activities and cytotoxicity. 5-(2-Hydroxy-3-methylbenzylidene)thiazolidine-2,4-dione (3) was the most potent AR inhibitor in this series, exerting uncompetitive inhibition with a K i value of 0.445 ± 0.013 µM. The IC50 value of compound 3 for L929 mouse fibroblast cells was determined as 8.9 ± 0.66 µM, pointing out its safety as an AR inhibitor. Molecular docking studies suggested that compound 3 exhibited good affinity to the binding site of AR (PDB ID: 4JIR). Based upon in silico absorption, distribution, metabolism, and excretion data, the compound is predicted to have favorable pharmacokinetic features. Taking into account the in silico and in vitro data, compound 3 stands out as a potential orally bioavailable AR inhibitor for the management of diabetic complications as well as nondiabetic diseases.

In Search for Multi-Target Ligands as Potential Agents for Diabetes Mellitus and Its Complications-A Structure-Activity Relationship Study on Inhibitors of Aldose Reductase and Protein Tyrosine Phosphatase 1B

Diabetes mellitus (DM) is a complex disease which currently affects more than 460 million people and is one of the leading cause of death worldwide. Its development implies numerous metabolic dysfunctions and the onset of hyperglycaemia-induced chronic complications. Multiple ligands can be rationally designed for the treatment of multifactorial diseases, such as DM, with the precise aim of simultaneously controlling multiple pathogenic mechanisms related to the disease and providing a more effective and safer therapeutic treatment compared to combinations of selective drugs. Starting from our previous findings that highlighted the possibility to target both aldose reductase (AR) and protein tyrosine phosphatase 1B (PTP1B), two enzymes strictly implicated in the development of DM and its complications, we synthesised 3-(5-arylidene-4-oxothiazolidin-3-yl)propanoic acids and analogous 2-butenoic acid derivatives, with the aim of balancing the effectiveness of dual AR/PTP1B inhibitors which we had identified as designed multiple ligands (DMLs). Out of the tested compounds, 4f exhibited well-balanced AR/PTP1B inhibitory effects at low micromolar concentrations, along with interesting insulin-sensitizing activity in murine C2C12 cell cultures. The SARs here highlighted along with their rationalization by in silico docking experiments into both target enzymes provide further insights into this class of inhibitors for their development as potential DML antidiabetic candidates.

Synthesis and Aldose Reductase Inhibitory Effect of Some New Hydrazinecarbothioamides and 4-Thiazolidinones Bearing an Imidazo[2,1-b]Thiazole Moiety

Objectives

To synthesize and characterize 2-[[6-(4-bromophenyl)imidazo[2,1-b]thiazol-3-yl]acetyl]-N-alkyl/arylhydrazinecarbothioamide and 3-alkyl/aryl-2-[((6-(4-bromophenyl)imidazo[2,1-b]thiazol-3-yl)acetyl)hydrazono]-5-nonsubstituted/methyl-4-thiazolidinone derivatives and evaluate them for their aldose reductase (AR) inhibitory effect.

Materials and Methods

2-[[6-(4-bromophenyl)imidazo[2,1-b]thiazol-3-yl]acetyl]-N-alkyl/arylhydrazinecarbothioamides (3a-f) and 3-alkyl/aryl-2-[((6-(4-bromophenyl)imidazo[2,1-b]thiazol-3-yl)acetyl)hydrazono]-5-nonsubstituted/methyl-4-thiazolidinones (4a-j) were synthesized from 2-[6-(4-bromophenyl)imidazo[2,1-b]thiazole-3-yl]acetohydrazide (2). Their structures were elucidated by elemental analyses and spectroscopic data. The synthesized compounds were tested for their ability to inhibit rat kidney AR.

Results

Among the synthesized compounds, 2-[[6-(4-bromophenyl)imidazo[2,1-b]thiazol-3-yl]acetyl]-N-benzoylhydrazinecarbothioamide (3d) showed the best AR inhibitory activity.

Conclusion

The findings of this study indicate that the different derivatives of the compounds in this study may be considered interesting candidates for future research.

Structure activity relationship studies on rhodanines and derived enethiol inhibitors of metallo-β-lactamases

Metallo-β-lactamases (MBLs) enable bacterial resistance to almost all classes of β-lactam antibiotics. We report studies on enethiol containing MBL inhibitors, which were prepared by rhodanine hydrolysis. The enethiols inhibit MBLs from different subclasses. Crystallographic analyses reveal that the enethiol sulphur displaces the di-Zn(II) ion bridging 'hydrolytic' water. In some, but not all, cases biophysical analyses provide evidence that rhodanine/enethiol inhibition involves formation of a ternary MBL enethiol rhodanine complex. The results demonstrate how low molecular weight active site Zn(II) chelating compounds can inhibit a range of clinically relevant MBLs and provide additional evidence for the potential of rhodanines to be hydrolysed to potent inhibitors of MBL protein fold and, maybe, other metallo-enzymes, perhaps contributing to the complex biological effects of rhodanines. The results imply that any medicinal chemistry studies employing rhodanines (and related scaffolds) as inhibitors should as a matter of course include testing of their hydrolysis products.

Stereochemical Investigations of Diastereomeric N-[2-(Aryl)-5-methyl-4-oxo-1,3-thiazolidine-3-yl]-pyridine-3-carboxamides by Nuclear Magnetic Resonance Spectroscopy (1D and 2D)

Some new N-[2-(aryl)-5-methyl-4-oxo-1,3-thiazolidine-3-yl]-pyridine-3-carboxamides were synthesized and their structures were investigated by IR, NMR (1H, 13C, and 2D), and mass spectra. The presence of C-2 and C-5 stereogenic centers on the thiazolidinone ring resulted in diastereoisomeric pairs. The configurations of two stereogenic centers were assigned based upon 1H NMR analysis of coupling constants and 2D nuclear overhauser enhancement spectroscopy (NOESY) experiment. Resolution of the diastereoisomers was performed by high performance liquid chromatography (HPLC) using a chiral stationary phase.

Evaluation of the anti-inflammatory/chondroprotective activity of aldose reductase inhibitors in human chondrocyte cultures

2-Thioxo-4-thiazolidinone derivatives active as aldose reductase inhibitors were able to control key inflammatory/degenerative events induced by IL-1β in human chondrocytes, appearing to be promising candidates in the search for novel anti-inflammatory agents.

Structure-activity relationships and molecular modelling of new 5-arylidene-4-thiazolidinone derivatives as aldose reductase inhibitors and potential anti-inflammatory agents

A series of 5-(carbamoylmethoxy)benzylidene-2-oxo/thioxo-4-thiazolidinone derivatives (6-9) were synthesized as inhibitors of aldose reductase (AR), enzyme which plays a crucial role in the development of diabetes complications as well as in the inflammatory processes associated both to diabetes mellitus and to other pathologies. In vitro inhibitory activity indicated that compounds 6-9a-d were generally good AR inhibitors. Acetic acid derivatives 8a-d and 9a-d were shown to be the best enzyme inhibitors among the tested compounds endowed with significant inhibitory ability levels reaching submicromolar IC50 values. Moreover, some representative AR inhibitors (7a, 7c, 9a, 9c, 9d) were assayed in cultures of human keratinocytes in order to evaluate their capability to reduce NF-kB activation and iNOS expression. Compound 9c proved to be the best derivative endowed with both interesting AR inhibitory effectiveness and ability to reduce NF-kB activation and iNOS expression. Molecular docking and molecular dynamics simulations were undertaken to investigate the binding modes of selected compounds into the active site of AR in order to rationalize the inhibitory effectiveness of these derivatives.

Organocatalysis in heterocyclic synthesis: DABCO as a mild and efficient catalytic system for the synthesis of a novel class of quinazoline, thiazolo [3,2-a]quinazoline and thiazolo[2,3-b] quinazoline derivatives

BACKGROUND

There are only limited publications devoted to the synthesis of especially thiazolo[3,2-a]quinazoline which involved reaction of 2-mercaptopropargyl quinazolin-4-one with various aryl iodides catalyzed by Pd-Cu or by condensation of 2-mercapto-4-oxoquinazoline with chloroacetic acid, inspite of this procedure was also reported in the literature to afford the thiazolo [2,3-b] quinazoline. So the multistep synthesis of the thiazolo[3,2-a]- quinazoline suffered from some flaws and in this study we have synthesized a novel class of thiazoloquinazolines by a simple and convenient method involving catalysis by 1,4-diazabicyclo[2.2.2]octane (DABCO).

RESULTS

A new and convenient one-pot synthesis of a novel class of 2-arylidene-2H-thiazolo[3,2-a]quinazoline-1,5-diones 9a-i was established through the reaction between methyl-2-(2-thio-cyanatoacetamido)benzoate (4) and a variety of arylidene malononitriles 8a-i in the presence of DABCO as a mild and efficient catalytic system via a Michael type addition reaction and a mechanism for formation of the products observed is proposed. Moreover 4 was converted to ethyl-2-[(4-oxo-3,4-dihydroquinazolin-2-yl)thio]acetate (10) upon reflux in ethanol containing DABCO as catalyst. The latter was reacted with aromatic aldehydes and dimethylformamide dimethylacetal (DMF-DMA) to afford a mixture of two regioselectively products with identical percentage yield, these two products were identified as thiazolo[3,2-a]quinazoline 9,13 and thiazolo[2,3-b]quinazoline 11,12 derivatives respectively. The structure of the compounds prepared in this study was elucidated by different spectroscopic tools of analyses also the X-ray single crystal technique was employed in this study for structure elucidation, Z/E potential isomerism configuration determination and to determine the regioselectivity of the reactions.

CONCLUSION

A simple and efficient one-pot synthesis of a novel class of 2-arylidene-2H-thiazolo[3,2-a]quinazoline-1,5-diones 9a-i was established through DABCO catalyzed Michael type addition reaction. In addition many fused quinazoline and quinazoline derivatives were synthesized which appeared as valuable precursors in synthetic and medicinal chemistry.

Catalyst-free synthesis of highly biologically active 5-arylidene rhodanine and 2,4-thiazolidinedione derivatives using aldonitrones in polyethylene glycol

A green, efficient synthesis of 5-arylidene rhodanine and 2,4-thiazolidinedione derivatives without using any external catalyst in polyethylene glycol (PEG) at 80°C has been described. Reaction procedure is very simple, short, and obtained yields are very high.

Diabetic peripheral neuropathy: should a chaperone accompany our therapeutic approach?

Diabetic peripheral neuropathy (DPN) is a common complication of diabetes that is associated with axonal atrophy, demyelination, blunted regenerative potential, and loss of peripheral nerve fibers. The development and progression of DPN is due in large part to hyperglycemia but is also affected by insulin deficiency and dyslipidemia. Although numerous biochemical mechanisms contribute to DPN, increased oxidative/nitrosative stress and mitochondrial dysfunction seem intimately associated with nerve dysfunction and diminished regenerative capacity. Despite advances in understanding the etiology of DPN, few approved therapies exist for the pharmacological management of painful or insensate DPN. Therefore, identifying novel therapeutic strategies remains paramount. Because DPN does not develop with either temporal or biochemical uniformity, its therapeutic management may benefit from a multifaceted approach that inhibits pathogenic mechanisms, manages inflammation, and increases cytoprotective responses. Finally, exercise has long been recognized as a part of the therapeutic management of diabetes, and exercise can delay and/or prevent the development of painful DPN. This review presents an overview of existing therapies that target both causal and symptomatic features of DPN and discusses the role of up-regulating cytoprotective pathways via modulating molecular chaperones. Overall, it may be unrealistic to expect that a single pharmacologic entity will suffice to ameliorate the multiple symptoms of human DPN. Thus, combinatorial therapies that target causal mechanisms and enhance endogenous reparative capacity may enhance nerve function and improve regeneration in DPN if they converge to decrease oxidative stress, improve mitochondrial bioenergetics, and increase response to trophic factors.

Recent developments and biological activities of thiazolidinone derivatives: a review

Thiazolidinone is considered as a biologically important active scaffold that possesses almost all types of biological activities. Successful introduction of ralitoline as a potent anti-convulsant, etozoline as a antihypertensive, pioglitazone as a hypoglycemic agent and thiazolidomycin activity against streptomyces species proved potential of thiazolidinone moiety. This diversity in the biological response profile has attracted the attention of many researchers to explore this skeleton to its multiple potential against several activities. This review is complementary to earlier reviews and aims to review the work reported on various biological activities of thiazolidinone derivatives from year 2000 to the beginning of 2011. Data are presented for active compounds, some of which have passed the preclinical testing stage.