In-vitro antiviral screening of some thiopyranothiazoles

Thiopyranothiazoles represent a promising class of drug-like molecules with broad pharmacological profiles. Some novel derivatives of isothiochromeno[4a,4-d]thiazole and chromeno[4',3':4,5]thiopyrano[2,3-d]thiazole were synthesized and screened against diverse viruses: coronavirus SARS, Influenza Viruses of type A and type B, Adeno- and Rhinovirus, Dengue Fever Virus, Respiratory Syncytial Virus, Rift Valley Fever Virus, Tacaribe Virus, Venezuelan Equine Encephalitis Virus, as well as Vaccinia and Human Cytomegalovirus. The antiviral activity assays revealed highly active isothiochromeno[4a,4-d]thiazole bearing phenazone fragment towards Influenza Virus type A (H1N1) with the selectivity index (SI) within 150. 5,8-Dihydro-2H-[1,3]thiazolo [5',4':5,6]thiopyrano [2,3-d][1,3]thiazol-2,6(3H)-diones showed moderate antiviral activity against influenza viruses and SARS-CoV. The obtained data indicate thiopyranothiazoles as promising class of fused 4-thiazolidinone derivatives possessing antiviral effects.

Evaluation of Anticancer and Antibacterial Activity of Four 4-Thiazolidinone-Based Derivatives

Heterocycles are commonly known for their unique features, e.g., antibacterial or anticancer properties. Although many synthetic heterocycles, such as 4-thiazolidinone (4-TZD), have been synthesized, their potential applications have not yet been fully investigated. However, many researchers have reported relevant results that can be a basis for the search for new potential drugs. Therefore, the aim of this study was to evaluate the cytotoxic, cytostatic, and antibacterial effects of certain 4-thiazolidinone-based derivatives, Les-3166, Les-5935, Les-6009, and Les-6166, on human fibroblasts (BJ), neuroblastoma (SH-SY5Y), epithelial lung carcinoma (A549), and colorectal adenocarcinoma (CACO-2) cell lines in vitro. All tested compounds applied in a concentration range from 10 to 100 µM were able to decrease metabolic activity in the BJ, A549, and SH-SY5Y cell lines. However, the action of Les-3166 was mainly based on the ROS-independent pathway, similarly to Les-6009. In turn, Les-5935 and Les-6166 were able to promote ROS production in BJ, A549, and SH-SY5Y cells, compared to the control. Les-3166, Les-6009, and Les-6166 significantly increased the caspase-3 activity, especially at the concentrations of 50 µM and 100 µM. However, Les-5935 did not induce apoptosis. Only Les-5935 showed a minor cytostatic effect on SH-SY5Y cells. Additionally, the antibacterial properties of the tested compounds against P. aeruginosa bacterial biofilm can be ranked as follows: Les-3166 > Les-5935 > Les-6009. Les-6166 did not show any anti-biofilm activity. In summary, the study showed that Les-5935, Les-6009, and Les-6166 were characterized by anticancer properties, especially in the human lung cancer cell. In cases of BJ, SH-SY5Y, and CACO-2 cells the anticancer usage of such compounds is limited due to effect visible only at 50 and 100 µM.

Synthesis of novel indole-thiazolidinone hybrid structures as promising scaffold with anticancer potential

A series of novel indole-azolidinone hybrids has been synthesized via Knoevenagel reaction of 5-fluoro-3-formyl-1H-indole-2-carboxylic acid methyl ester and some azolidinones differing in heteroatoms in positions 1, 2 and 4. Their anticancer activity in vitro was screened towards MCF-7 (breast cancer), HCT116 (colon cancer), HepG2 (hepatoma), HeLa (cervical cancer), A549 (lung cancer), WM793 (melanoma) and THP-1 (leukemia) cell lines, and a highly active 5-fluoro-3-(4-oxo-2-thioxothiazolidin-5-ylidenemethyl)-1H-indole-2-carboxylic acid methyl ester (3a) was identified and subjected to in-depth investigation of cytotoxicity mechanisms. This compound was found to possess the highest cytotoxic action towards tumor cells comparing with the action of other derivatives (1, 3b, 3c, 3d, 3e). Compound 3a exhibited toxicity toward MCF-7, HCT116, and A549, HepG2 cancer cells, while the non-malignant cells (human keratinocytes of HaCaT line and murine embryonic fibroblasts of Balb/c 3T3 line) possessed moderate sensitivity to it. The compound 3a induced apoptosis in studied tumor cells via caspase 3-, PARP1-, and Bax-dependent mechanisms; however, it did not affect the G1/S transition in HepG2 cells. The compound 3a impaired nuclear DNA in HepG2, HCT116, and MCF-7 cells without intercalating this biomolecule, but much less DNA damage events were induced by 3a in normal Balb/c 3T3 fibroblasts compared with HepG2 carcinoma cells. Thus, 5-fluoro-3-(4-oxo-2-thioxothiazolidin-5-ylidenemethyl)-1H-indole-2-carboxylic acid methyl ester 3a was shown to trigger DNA damage and induce apoptosis of human tumor cells and it might be considered as an anticancer agent perspective for in-depth studies.

4-Thiazolidinone-based derivatives do not affect differentiation of mouse embryo fibroblasts (3T3-L1 cell line) into adipocytes

Nowadays, diabetes mellitus type 2 (T2DM) is a serious problem in western European societies and in the United States. Thiazolidinediones (TZDs) are a broad group of compounds used to decrease insulin resistance in TDM2. To date, it has been believed that TZDs act mainly through activation of peroxisome proliferator-activated receptor gamma (PPARγ). The PPARγ receptor is important in differentiation of preadipocytes into mature adipocytes. Therefore, given the potential of structurally related thiopyrano[2,3-d]thiazoles Les-2194 and Les-3377 and 4-thiazolidinone derivative Les-3640 to interact with the PPARγ receptor, the aim of the present study was to evaluate the impact of the 4-thiazolidinone-based derivatives mentioned above on the process of 3T3-L1 cell line differentiation into adipocytes. In the first part of our study, we prove that Les-2194, Les-3377, and Les-3640 are cytotoxic to 3T3-L1 cells. In the next stage, we determine that Les-2194, Les-3377, and Les-3640 stimulate lipid accumulation (using the ORO staining method) and induce specific gene expression (Dlk1, Fabp4, Vegfa, Pai-1, Resistin, Adiponectin, and Pparγ). Our data show that rosiglitazone, pioglitazone, Les-2194, and Les-3640 at a concentration of 2 μM do not affect 3T3-L1 cell viability and do not activate the apoptotic process. Only Les-3377 decreased the number and metabolism of the cells. Although all the studied compounds influenced the expression of Dlk1, Fabp4, Vegfa, Pai-1, Resistin, Adiponectin, and Pparγ genes, none of them caused gene expression similar to that induced by rosiglitazone or pioglitazone. The ORO staining showed that rosiglitazone and pioglitazone induced lipid accumulation in the 3T3-L1 cell line, which is a marker of mature adipocytes. Only rosiglitazone increased Pparγ protein expression after 14 days of differentiation.

4-thiazolidinone-based derivatives rosiglitazone and pioglitazone affect the expression of antioxidant enzymes in different human cell lines

PPARγ regulate the expression of genes involved in peripheral insulin sensitivity, adipogenesis, and glucose homeostasis. Moreover, PPARγ agonists, such as pioglitazone and rosiglitazone, are used in the treatment of various diseases, e.g. diabetes (type II), atherosclerosis, inflammatory skin disease, and some types of cancers. PPARγ agonists have also been found to reduce oxidative-stress (OS) and OS-induced apoptosis. Therefore, the aim of the present study was to evaluate the impact of 4-thiazolidinone-based derivatives Les-2194, Les-3377, and Les-3640 on the expression of antioxidant enzymes in human squamous cell carcinoma (SCC-15), lung carcinoma (A549), colon adenocarcinoma (CACO-2), and skin fibroblast (BJ) cell lines. After 24 h of exposure, Les-2194 caused an increase in ROS production in the SCC-15 and CACO-2 cell lines; however, no changes in caspase-3 activity and metabolic activity were observed. Nevertheless, the Ki67 level was significantly decreased. Les-3377 was able to increase ROS production in all tested cell lines, but no impact on metabolic activity and caspase-3 activity were noticed. In turn, Les-3640 was able to induce ROS overproduction in BJ, SCC-15, and CACO-2 and did not affect metabolic activity. However, an increase in caspase-3 activity was observed at the 10 µM concentration in all tested cell lines. All tested compounds were able to influence CAT and SOD1 expression and decreased (Les-2194 in the BJ cells) or increased (Les-3640 in the SCC-15 and CACO-2 cells) PPARγ expression.

5-Arylidene-2-(4-hydroxyphenyl)aminothiazol-4(5H)-ones with selective inhibitory activity against some leukemia cell lines

The data on the pharmacology of 4-thiazolidinones showed that 5-ene-2-(imino)amino-4-thiazolidinones are likely to comprise one of the most promising groups of compounds possessing anticancer properties. A series of 5-arylidene-2-(4-hydroxyphenyl)aminothiazol-4(5H)-ones was designed, synthesized, and studied against 10 leukemia cell lines, including the HL-60, Jurkat, K-562, Dami, KBM-7, and some Ba/F3 cell lines. The structure-activity relationship analysis shows that almost all tested 5-arylidene-2-(4-hydroxyphenyl)aminothiazol-4(5H)-ones were characterized by ІС₅₀ values lower or comparable to that of the control drug chlorambucil. Among the tested compounds, (5Z)-5-(2-methoxybenzylidene)- (12), (5Z)-(2-ethoxybenzylidene)- (21), (5Z)-5-(2-benzyloxybenzylidene)- (25), and (5Z)-5-(2-allyloxybenzylidene)-2-(4-hydroxyphenylamino)thiazol-4(5H)-ones (28) possessed the highest antileukemic activity at submicromolar concentrations (ІС₅₀  = 0.10-0.95 µM).

Induction of Cyp450 enzymes by 4-thiazolidinone-based derivatives in 3T3-L1 cells in vitro

4-Thiazolidinones and related derivatives are regarded as privileged structures in medicinal chemistry and a source of new drug-like compounds. To date it is known that thiazolidinones are able to induce CYP1A1 activity in 3T3-L1 cells. Therefore, to extend the knowledge of the mechanism of thiazolidinones in the cell, four chemically synthesized heterocycles were tested on 3T3-L1 cells. The 3T3-L1 cells were exposed to Les-2194, Les-3640, Les-5935, and Les-6166. Our study showed that 1 μM βNF, Les-2194, and Les-6166 decreased the expression of Ahr mRNA. In turn, βNF, Les-2194, and Les-3640 increased the Cyp1a1 mRNA expression at the same time interval. On the other hand, Les-5935 was found to decrease the Cyp1a1 mRNA expression. Interestingly, the expression of Cyp1a2 mRNA was activated only by βNF and Les-2194. The expression of Cyp1b1 mRNA in the 3T3 cell line increased after the βNF and Les-2194 treatment but declined after the exposure to Les-5935 and Les-6166. Moreover, the Les-2194 and Les-5935 compounds were shown to increase the activity of EROD, MROD, and PROD. Les-3640 increased the activity of EROD and decreased the activity of PROD. In turn, the treatment with Les-6166 resulted in an increase in the activity of EROD and a decrease in the activity of MROD and PROD in the 3T3-L1 cells.

Assessing different thiazolidine and thiazole based compounds as antileishmanial scaffolds

The compounds from eight different thiazolidine and thiazole series were assessed as potential antileishmanial scaffolds. They were tested for antileishmanial activity against promastigotes of Leishmania major using in vitro primary screen and dose response assays. The compounds from six thiazolidine and thiazole series were identified as the hits with antileishmanial activity against L. major. However, the analyses of structure-activity relations (SARs) showed that the interpretable SARs were obtained only for phenyl-indole hybrids (compounds C1, C2, C3 and C5) as the most effective compounds against L. major promastigotes (IC₅₀ < 10 µM) with low toxicity to human fibroblasts. For the scaffold of these compounds, the most significant SAR patterns were: free N3 position of thiazolidinone core, absence of big fragments at the C5 position of thiazolidinone core and presence of halogen atoms or nitro group in the phenyl ring of phenyl-indole fragment. As previous studies showed that these compounds also have activity against the two Trypanosoma species, Trypanosoma brucei and Trypanosoma gambiense, their scaffold could be associated with a broader antiparasitic activity.