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Niclosamide, previously used as an anthelmintic drug is currently being repurposed for its anticancer activity. Niclosamide is a brick like biopharmaceutical classification system (BCS) class II drug with poor aqueous solubility and dissolution consequently leading to low bioavailability. By considering the physicochemical properties and geometry of niclosamide, inclusion complex with cyclodextrin was prepared by freeze drying method and characterized using FT-IR, DSC, PXRD, and 1HNMR. In silico molecular modeling study was performed to study the possible interactions between niclosamide and cyclodextrin. The anticancer activity of niclosamide formulation was evaluated through in vitro cell cytotoxicity study using various cancer cell lines. The potential of niclosamide complex for improvement of the bioavailability was evaluated in male BALB/c mice. In vitro cytotoxicity studies indicated significantly higher cytotoxicity at lower concentrations and the pharmacokinetic studies showed significant improvement in Cmax and Tmax of niclosamide from cyclodextrin complex in comparison to pure niclosamide alone.

Synthesis of twenty new curcumin inspired 2-chloro/phenoxy quinoline derivatives is outlined in this study. The obtained new chemical entities were screened in vitro for their cytotoxic activity towards various tumor cell lines. Of the compounds screened, 6c and 9d exhibited significant activity and the most active analogue 6c displayed promising cytotoxicity against PC-3 (IC50 of 3.12 ± 0.11 μM), DU-145, NCI-H460 and 4 T1 cell lines. Further, 6c and 9d have 2.1 and 1.4 times more aqueous solubility, respectively, than curcumin. Additionally, the promising candidate 6c could induce G2/M cell cycle arrest and apoptosis in PC-3 cells, as determined by AO-EB staining, DAPI staining, analysis of ROS levels as well as annexin binding assay.

Topoisomerases (topo-I and topo-II) have occupied a significant role in DNA replication, transcription, and are a promising set of antitumor targets. In the present approach, a series of new 4 beta-amidotriazole linked podophyllotoxin derivatives (10a-i and 11a-k) were designed, synthesized by employing the click chemistry and their biological activities were evaluated. The majority of derivatives showed promising antiproliferative activity with IC50 values ranging from 1 to 10 mu M on the six human cancer cell lines; cervical (HeLa), breast (MCF-7), prostate (DU-145), lung (A549), liver (HepG2) and colon (HT-29). Among them, some of the congeners 10b, 10g and 10i have shown remarkable cytotoxicity with IC50 values of, < 1 mu M against the tested cancer cell lines and found to be more active than etoposide. Topoisomerase-mediated DNA relaxation assay results showed that the derivatives could efficiently inhibit the activity of topoisomerase-II. In addition, flow cytometry analysis on DU-145 cells revealed that these compounds arrest G2/M phase of cell cycle. Further apoptotic studies were also performed on these DU-145 cells, which showed that this class of compounds could induce apoptosis effectively

Two new series of s-triazine derivatives appended with benzimidazole (15a–h) and benzothiazole derivatives (16a–h) are synthesized, and structure–activity relationships on anticancer activity of these 15a–h and 16a–h were probed. In vitro inhibitory activity against the growth of six cancer cell lines, viz., MCF-7, MDAMB-231, PC-3, DU-145, HT-29 and HGC-27 was evaluated for synthesized analogues. Among the two series of compounds, derivatives containing benzimidazole scaffold were found to be relatively potent over benzothiazole analogues. In accordance with our previous observation, within benzimidazole derivatives, tri-substituted s-triazine derivatives were found to be more potent over di-substituted derivatives irrespective of cell lines. Structure–activity relationships provided useful insights into these classes of compounds and paved the way to design novel analogues with more potency.

In our venture towards the development of effective cytotoxic agents, a panel of triazole linked 3-benzylidene isatin hybrids were synthesized and characterized by IR, 1H NMR, 13C NMR and Mass spectral analysis. All the newly synthesized target compounds were assessed against DU145 (prostate), PC-3 (prostate), MDA-MB-231 (breast), BT549 (breast), A549 (lung) and HeLa (cervical) human cancer cell lines by employing MTT assay for their cytotoxic potential. Significantly, compound Z-8l was found to be most potent amongst all the tested compounds with an IC50 value of (3.7 ± 0.05 μM) on DU145 cells. The most active compound (Z-8l) was also tested on RWPE-1 (normal prostate) cells and was found to be safe compared to the DU145 cells. The influence of the cytotoxic compound Z-8l on the cell cycle distribution was assessed on the DU145 cell line, exhibiting a cell cycle arrest at the G2/M phase. Additionally, treatment with compound Z-8l caused collapse of mitochondrial membrane potential (DΨm) in DU145 cells. Moreover, acridine orange/ethidium bromide staining, DAPI nuclear staining, DCFDA staining and annexin V binding assay confirmed that compound Z-8l can induce cell apoptosis in DU145 cells. Western blotting was performed to examine the appearance of active forms of cytochrome c, Bax, Bcl2 and PARP (Poly ADP ribose polymerase), indicator proteins of apoptosis in DU145 cells; the study confirmed the triggering of mitochondrial mediated apoptotic pathway upon exposure of compound Z-8l.

A new series of (E)-benzo[d]imidazol-2-yl)methylene)indolin-2-one derivatives has been synthesized and evaluated for their in vitro cytotoxic activity against a panel of selected human cancer cell lines of prostate (PC-3 and DU-145) and breast (BT-549, MDA-MB-231, MCF-7, 4T1), non-small lung (A549) and gastric (HGC) cancer cells along with normal breast epithelial cells (MCF10A). Among the tested compounds, 8l showed significant cytotoxic activity against MDA-MB-231 and 4T1 cancer cells with IC50 values of 3.26 ± 0.24 μM and 5.96 ± 0.67 μM respectively. The compounds 8f, 8i, 8l and 8o were also screened on normal human breast epithelial cells (MCF10A) and found to be safer with lesser cytotoxicity. The treatment of MDA-MB-231 cells with 8l led to inhibition of cell migration ability through disruption of F-actin protein assembly. The flow-cytometry analysis reveals that the cells arrested in G0/G1 phase of the cell cycle. Further, the compound 8l induced apoptosis of MDA-MB-231 cells was characterized by different staining techniques such as Acridine Orange/Ethidium Bromide (AO/EB), DAPI, annexin V-FITC/PI, Rhodamine-123 and MitoSOX red assay. Western blot studies demonstrated that the compound 8l treatment led to activation of caspase-3, increased expression of cleaved PARP, increased expression of pro-apoptotic Bax and decreased expression of anti-apoptotic Bcl-2 in MDA-MB-231 cancer cells.

A series of new (Z)-3-(3'-methoxy-4'-(2-amino-2-oxoethoxy)benzylidene)indolin-2-one derivatives has been synthesized and evaluated for their cytotoxic activity against selected human cancer cell lines of prostate (PC-3 and DU-145), breast (BT-549 and MDA-MB-231) and non-tumorigenic prostate epithelial cells (RWPE-1). Among the tested, one of the compounds 4p exhibited potent cytotoxicity selectively on prostate cancer cell lines (PC-3 and DU-145; IC50: 1.89 ± 0.6 and 1.94 ± 0.2 μM, respectively). Further experiments were conducted with 4p on PC-3 cancer cells to study the mechanisms of growth inhibition and apoptosis inducing effect. Treatment of PC-3 cells with test compound 4p resulted in inhibition of cell migration through disorganization of F-actin protein. The flow-cytometry analysis results showed that the compound arrested PC-3 cancer cells in the G2/M phase of cell cycle in a dose dependent manner. Hoechst staining and annexin-V binding assay revealed that the compound 4p inhibited tumor cell proliferation through induction of apoptosis. Western blot studies demonstrated that the compound 4p treatment led to activation of caspase-3, increased expression of pro-apoptotic Bax and significantly decreased expression of anti-apoptotic Bcl-2 in human prostate cancer PC-3 cells. In addition, the mitochondrial membrane potential (ΔΨm) was also affected and the levels of intracellular Ca(2+) were raised.

In our endeavor towards the development of effective cytotoxic agents, a series of oxindole linked indolyl-pyrimidine derivatives were synthesized and characterized by IR, 1 H NMR, 13 C NMR and Mass spectral analysis. All the newly synthesized target compounds were assessed against PA-1 (ovarian), U-87MG (glioblastoma), LnCaP (prostate), and MCF-7 (Breast) cancer cell lines for their cytotoxic potential, with majority of them showing inhibitory activity at low micro-molar concentrations. Significantly, compound 8e was found to be most potent amongst all the tested compounds with an IC 50 value of (2.43 ± 0.29 μM) on PA-1 cells. The influence of the most active cytotoxic compound 8e on the cell cycle distribution was assessed on the PA-1 cell line, exhibiting a cell cycle arrest at the G2/M phase. Moreover, acridine orange/ethidium bromide staining and annexin V binding assay confirmed that compound 8e can induce cell apoptosis in PA-1 cells. These preliminary results persuade further investigation on the synthesized compounds aiming to the development of potential cytotoxic agents.

A facile one-pot method for the synthesis of novel podophyllotoxin-thiourea congeners has been developed by using NH2SO3H/NaI system. Interestingly, 4β-azido podophyllotoxin reduction with concomitant aryl isothiocyanates coupling under mild reaction conditions has been achieved. These compounds have been investigated for their in vitro cytotoxicity against A549, MDA MB-231, DU-145, LNCaP, and HGC-27 cancer cell lines. Some of the representative compounds have selectively exhibited cytotoxicity on DU-145 (human prostate cancer) cells and the most potent compound was 4a (IC50 of 0.50 ± 0.03 μM) with optimal safety therapeutic window (81.7 fold) on normal human prostate cell line (RWPE-1, IC50 of 40.85 ± 0.78). The flow-cytometric analysis of the compound 4a in prostate cancer cells indicated a strong G2/M-phase arrest and significant topoisomerase II inhibition activity. Furthermore, these compounds induce apoptosis as observed by Acridine Orange and Ethidium Bromide (AO/EB) staining and Annexin V binding assay. Molecular docking results of the title compounds with topoisomerase-IIα were presented as theoretical support for the experimental data.

As a part of our endeavour toward the synthesis of new heterocyclic bioactive agents, three series of Δ2-isoxazoline fused cyclopentane derivatives (27 compounds) were synthesized and characterized by IR, 1H NMR, 13C NMR and MS analysis. The newly synthesized target compounds were evaluated for their preliminary in vitroantimicrobial and anticancer activities. The results indicated that compounds 4b, 4h, 4i, 5d and 5g displayed remarkable anti-microbial activity with respect to their standard drugsAmpicillin, Gentamycin and Amphotericin B. In preliminary MTT cytotoxicity studies, compound 4i was found to be equipotent to the standard drugEtoposide against MCF-7. The influence of the most active cytotoxic compound 4i on the cell cycle distribution was evaluated in the MCF-7 cell line, which displayed a cell cycle arrest at the S phase. Moreover, acridine orange/ethidium bromide staining, annexin V binding assay and mitochondrial membrane potential revealed that compound 4i can induce cell apoptosis in MCF-7 cells. Compounds 4b and 4h are potential leads as antimicrobials owing to no significant cell toxicity observed in the present study. Docking studies revealed that compound 4i binds to Phe1145, Glh698, Met696, Cys1191, Met1169 and Ile1167 on DNA methyltransferase (DNMT1) protein and inhibition of DNMT1 could be the possible mechanism of action for these compounds.

With an aim to develop new curcumin inspired analogues as potent anticancer agents, we synthesized a series of (1E,4E)-1-phenyl-5-(3-phenylimidazo[1,2-a]pyridin-2-yl)penta-1,4-dien-3-ones (12a-t) as tubulin polymerization inhibitors. An initial screening was carried out to evaluate their cytotoxic potential on a panel of six cancer cell lines namely, cervical (HeLa), gastric (HGC-27), lung (NCI-H460), prostate (DU-145 and PC-3) and breast (4T1), using MTT assay. Among the compounds tested, compounds 12e, 12r and 12t showed potent growth inhibition and 12t {(1E,4E)-1-(3-(3,4-difluorophenyl)imidazo[1,2-a]pyridin-2-yl)-5-(2,4,6-trimethoxyphenyl)penta-1,4-dien-3-one} being the most active member of the series inhibited the growth of all the tested cell lines with IC50 values varying from 1.7 - 2.97 μM. Moreover, 12t showed promising cytotoxicity on PC-3, HGC-27 and HeLa cell lines with IC50 values of 2.11 ± 0.27 μM, 2.21 ± 0.25 μM and 2.53 ± 0.01 μM respectively. The results from aqueous solubility test showed that compounds 12e and 12t have 1.7 and 2.8 times more aqueous solubility than curcumin. Interestingly, the most active compound 12t was found to be nearly 2 times more selective on PC-3 cells as well as safe on normal human prostate (RWPE-1) cells. In addition, compound 12t efficiently inhibited tubulin polymerization with IC50 value of 8.44 ± 0.13 μM and molecular modelling studies disclosed that 12t binds at the colchicine binding site of the tubulin. Cell cycle analysis revealed that 12t arrests PC-3 cells in G2/M phase in a dose dependant manner. Further, treatment of PC-3 cells with 12t showed typical apoptotic morphology, also led to the impairment of mitochondrial membrane potential (DΨm) and increased levels of reactive oxygen species (ROS). Altogether, the results from acridine orange/ethidium bromide (AO-EB) and DAPI staining studies, annexin V-FITC/propidium iodide staining assay, analysis of mitochondrial membrane potential (DΨm) and reactive oxygen species (ROS) levels undoubtedly demonstrated the induction of apoptosis in PC-3 cells by compound 12t.

A total of twenty-two novel coumarin triazole hybrids (4a-4k and 6a-6k) were synthesized from orcinol in good to excellent yields of 70–94%. The structures of all the synthesized compounds were elucidated by spectroscopic techniques such as 1H NMR, 13C NMR, and HRMS. The anti-inflammatory potential of synthesized compounds was investigated against the proinflammatory cytokine, TNF-α on U937 cell line and compounds 4d, 4j, and 6j were found to exhibit promising anti-inflammatory activity. These three compounds were further screened against TNF-α on LPS-stimulated RAW 264.7 cells, which confirm their anti-inflammatory potential. Furthermore, the above said active compounds were tested for their inhibitory effect on RANKL-induced osteoclastogenesis in RAW 264.7 cells by using tartrate resistant acid phosphatase (TRAP) staining assay at 10 µM. Molecular mechanism studies demonstrated that compound 4d exhibited dose dependent inhibition of RANKL-induced osteoclastogenesis by suppression of the NF-kB pathway. Thus, compound 4d is a promising candidate for further optimization to develop as a potent anti-osteoporotic agent.

We herein report the design, synthesis and molecular docking studies of 2,4-thiazolidinedione derivatives containing benzene sulphonyl group which are docked against the Peroxisome Proliferator Activated Receptor (PPARγ) target. Compound 7p was most effective in lowering the blood glucose level as compared to standard drugs pioglitazone and rosiglitazone. Compound 7p exhibited potent PPAR-γ transactivation of 61.2% with 1.9 folds increase in gene expression. In molecular docking studies 7p showed excellent interactions with amino acids TYR 473, SER 289, HIE 449, TYR 327, ARG 288, MET 329 and LEU 228. Compound 7p did not cause any damage to the liver without any noteworthy weight gain and may be considered as promising candidates for the development of new antidiabetic agents.

A series of thiazolidinedione based amide derivatives were designed, synthesized and docked against the PPARγ receptor target. 11 compounds from the series with good glide scores were selected for in vivo antidiabetic study based on streptozotocin induced diabetic rat model. It was observed that 4 compounds (6c, 6e, 6m &6n) showed significantly good antidiabetic activity in comparison to rosiglitazone and pioglitazone as reference drugs. Compound 6c appeared as the most potent derivative in lowering blood glucose level and showed excellent interaction with SER 342, ILE 281, pi-pi interaction with ARG 288 and halogen bond interaction with LYS 367. Further, PPARγ transactivation and gene expression studies of compound 6c were carried out to investigate the possible mechanism of action through PPARγ modulation. Compound 6c exhibited 53.65% transactivation and elevated PPARγ gene expression by 2.1 folds. The biochemical parameters (AST, ALT and ALP levels) were found within the range with no noteworthy damage to liver.

A series of thiazole linked indolyl-3-glyoxylamide derivatives were synthesized and evaluated for their in vitro cytotoxic activity against DU145 (prostate), PC-3 (prostate), A549 (lung) and HCT-15 (colon) cancer cell lines by employing the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Among all the synthesized compounds, compound 13d displayed cytotoxicity of IC50 = 93 nM towards DU145 cancer cell line. The most active compound 13d was also tested on RWPE-1 cells and was found to be safe compared to the DU145 cells. The target compounds were also evaluated for their inhibition activity of tubulin polymerization. Further, the treatment of compound 13d on DU145 cells led to the inhibition of cell migration ability. The detailed studies such as acridine orange/ethidium Bromide (AO/EB), DAPI, annexin V-FITC/propidium iodide staining assay suggested that the compound 13d induced apoptosis in DU145 cells. The influence of the cytotoxic compound 13d on the cell cycle distribution was assessed on the DU145 cell line, exhibiting a cell cycle arrest at the G2/M phase. Moreover, the treatment with compound 13d caused collapse of mitochondrial membrane potential and elevated intracellular ROS levels in DU145 cells. The results from molecular modelling studies revealed that these compounds bind at the colchicine binding site of the tubulin. Thus, this new molecular scaffold could be a new lead for the development of anticancer agents that target tubulin.

Several rhodanine derivatives ( 9 – 39 ) were synthesized for evaluation of their potential as anticancer agents. Villsmeier cyclization to synthesize aza-aromatic aldehydes, rhodanine derivatives preparation and Knoevenagel type of condensation between the rhodanines and aza-aromatic aldehydes are key steps used for the synthesis of 31 compounds. In vitro antiproliferative activity of the synthesized rhodanine derivatives ( 9 – 39 ) was studied on a panel of six human tumor cell lines viz. HGC, MNK-74, MCF-7, MDAMB-231, DU-145 and PC-3 cell lines. Some of the compounds were capable of inhibiting the proliferation of cancer cell lines at a micromolar concentration. Six compounds are found to be potent against HGC cell lines; compound 15 is found to be active against HGC – Gastric, MCF7 – Breast Cancer and DU145 – Prostate Cancer cell lines; compound 39 is potent against MNK-74; four compounds are found to be potent against MCF-7 cell lines; three compounds are active against MDAMB-231; nine compounds are found to be potent against DU-145; three compounds are active against PC-3 cell lines. These compounds constitute a promising starting point for the development of novel and more potent anticancer agents in future.

In our endeavour towards the development of potent cytotoxic agents, a series of some new curcumin inspired indole analogues, in which indole and phenyl moieties are linked on either sides of 1,5-diaryl-1,4-pentadien-3-one system have been synthesized and characterized by spectral data. All the newly synthesized analogues were tested for their cytotoxic potential against a panel of eight cancer cell lines namely, lung (A549), breast (MDA-MB-231, BT549 and 4T1), prostate (PC-3, DU145), gastric (HGC-27) and cervical (HeLa). Notably, among all the compounds tested, compounds 11c , 11d and 11f showed potent growth inhibition on PC-3 and BT549 with IC 50 values in the range of 3.12–6.34 μM and 4.69–8.72 μM respectively. The most active compound ( 11c ) was also tested on RWPE-1 (normal prostate) cells and was found to be safe compared to the PC-3 cells. In tubulin polymerization assay, compounds 11c and 11f effectively inhibited microtubule assembly with IC 50 values of 10.21 ± 0.10 and 8.83 ± 0.06 μM respectively. The results from molecular modelling studies revealed that these compounds bind at the colchicine binding site of the tubulin. Moreover, DAPI and acridine orange/ethidium bromide staining studies indicated that compounds 11c and 11f can induce apoptosis in PC-3 cells. Further flow-cytometry analysis revealed that compound 11c arrests PC-3 cells in G2/M phase of the cell cycle while compound 11f treatment resulted in moderate increase in the G2/M population. Additionally, the treatment by these compounds led to the impairment of mitochondrial membrane potential (DΨm) in PC-3 cells.

A series of novel sEH inhibitors containing a N-substituted piperidine ring [N-urea (8a–i) (9a–l) and amide derivatives (6a–l) (7a–l)] with pyrazole (a five-membered polar heterocycle) as a pharmacophore lead for sEH inhibition have been designed, synthesized and evaluated as novel analogues to reduce blood pressure elevation and inflammatory roles by acting as sEH inhibitors. The synthesized compound shows varying degree of selectivity towards the sEH enzymes. Particularly compounds 9g and 8h emerged as the most potent sEH inhibitor displaying IC50 values of 0.224 ± 0.014 and 0.220 ± 0.03 μM for in vitro sEH inhibition. Molecular docking studies of the designed sEH dual inhibitors are performed using 1ZD5 for sEH as the targeted proteins and which revealed H-bond interactions similar to AUDA. Structure–activity relationships provided useful insights in these classes of compounds and paved the way to design novel analogues with increased potency. Schematic representation of proposed sEH Inhibitors.

A new route for the synthesis of novel 2,3,6,7-tetramethoxy phenanthrene amine precursor has been successfully accomplished. Subsequently, this amine precursor has been directly utilized for the synthesis of a new series of 4-aza-2,3-dihydropyridophenanthrene derivatives via a three component reaction with tetronic acid and substituted aldehydes. These compounds were evaluated for their cytotoxic potential against human lung (A549), prostate (PC-3 and DU145), breast (MDA-MB-231 and 4T1), gastric (HGC-27), colon (Caco-2) and cervical (HeLa) cancer cell lines. Compound 10l showed significant anticancer profile against DU145 cell line with an IC50 value of 2.6 ± 0.34 μM. Disruption of F-actin cytoskeleton structure and cell migration inhibition in DU145 cells clearly indicate that the tumor progression and metastasis are affected by this compound (10l). Cell cycle analysis revealed that it arrests the cells in G2/M phase. Acridine orange/ethidium bromide (AO/EB) staining, Hoechst staining and annexin-V binding assays showed that cell proliferation is inhibited through induction of apoptosis. Moreover, its treatment leads to collapse of the mitochondrial membrane potential (DΨm).

A series of new 4′- O -alkylamino-tethered-benzylideneindolin-2-one derivatives has been synthesized and evaluated for their anti-proliferative activity against selected human cancer cell lines of lung (A549), prostate (DU-145), breast (BT549 and MDA-MB-231) and normal breast epithelial cells (MCF-10A). Gratifyingly, the compounds 5j , 5o and 5r exhibited potent cytotoxicity against breast cancer cell lines (BT549 and MDA-MB-231) with IC 50 values in the range of 1.26–2.77 μM, and are found to be safer with lesser cytotoxicity on normal breast epithelial cells (MCF-10A). Further, experiments were conducted with these compounds 5j , 5o and 5r on MDA-MB-231 cancer cells to study the mechanism of growth inhibition and apoptosis inducing effect. Treatment of MDA-MB-231 cells with test compounds resulted in inhibition of cell migration through disorganization and disruption of F-actin capping protein. The flow-cytometry analysis results showed that the compound 5o arrested MDA-MB-231 cells in G0/G1 phase of cell cycle in a dose dependent manner. Hoechst staining study revealed that the test compounds inhibited tumor cell proliferation through induction of apoptosis. In addition, the mitochondrial membrane potential (DΨm) was affected and the increased level of reactive oxygen species (ROS) was noted in MDA-MB-231 cells.