Design, synthesis and biological evaluation of novel cationic liposomes loaded with melphalan for the treatment of cancer.

Therapeutically active lipids in drug delivery systems offer customization for enhanced pharmaceutical and biological effects, improving safety and efficacy. Biologically active N, N-didodecyl-3,4-dimethoxy-N-methylbenzenaminium lipid (Q) was synthesized and employed to create a liposome formulation (FQ) encapsulating melphalan (M) through a thin film hydration method. Synthesized cationic lipids and their liposomal formulation underwent characterization and assessment for additive anti-cancer effects on myeloma and melanoma cancer cell lines. These effects were evaluated through various studies, including cytotoxicity assessments, cell cycle arrest analysis, apoptosis measurements, mitochondrial membrane potential depolarization, DNA fragmentation, and a significant reduction in tumorigenic potential, as evidenced by a decrease in both the number and percentage area of cancer spheroids.

Synthesis and biological evaluation of bergenin-1,2,3-triazole hybrids as novel class of anti-mitotic agents.

In continuation of our investigation of pharmacologically-motivated natural products, we have isolated bergenin (1) as a major compound from Mallotus philippensis, which is deployed in different Indian traditional systems of medicine. Here, a series of bergenin-1,2,3-triazole hybrids were synthesized and evaluated for their potentials against a panel of cancer cell lines. Several of the hybrid derivatives were found more potent in comparison to parent compound bergenin (1). Among them, 4j demonstrated potent activity against A-549 and HeLa cell lines with IC50 values of 1.86 µM and 1.33 µM, respectively, and was equipotent to doxorubicin. Cell cycle analysis showed that 4j arrested HeLa cells at G2/M phase and lead to accumulation of Cyclin B1 protein. Cell based tubulin polymerization assays and docking studies demonstrated that 4j disrupts tubulin assembly by occupying colchicine binding pocket of tubulin.

Synthesis and biological evaluation of new bisindole-imidazopyridine hybrids as apoptosis inducers.

A series of diindolylmethanes (5a-t) were designed, synthesized, and examined for their cytotoxicity against four human cancer cell lines like prostate (DU-145), lung (A549), breast (MCF-7) and cervical cancer (HeLa). These results revealed that among all the hybrids, two (5k and 5r) were identified and exhibited significant cytotoxic effect against A549 cancer cells with IC50 values of 1.65 ±â€¯0.3 and 1.80 ±â€¯0.8 µM respectively. To investigate the reasons for the cytotoxic activity, the conventional biological assays were carried out with 5k and 5r on the A549 cancer cells. Both hybrids led to the arrest of A549 cell lines at the G2/M phase of the cell cycle and strongly induced apoptosis. Further the apoptotic effects of 5k and 5r were confirmed by ROS, annexin-V FITC, and mitochondrial membrane potential. Moreover, structure-activity relationships were elucidated with various substitutions on these hybrids.

Design and synthesis of DNA-intercalative naphthalimide-benzothiazole/cinnamide derivatives: cytotoxicity evaluation and topoisomerase-IIα inhibition.

A new series of different naphthalimide-benzothiazole/cinnamide derivatives were designed, synthesized and tested for their in vitro cytotoxicity on selected human cancer cell lines. Among them, derivatives 4a and 4b with the 6-aminobenzothiazole ring and 5g with the cinnamide ring displayed potent cytotoxic activity against colon (IC50: 3.715 and 3.467 µM) and lung cancer (IC50: 4.074 and 3.890 µM) cell lines when compared to amonafide (IC50: 5.459 and 7.762 µM). Later, the DNA binding studies for these selected derivatives (by CD, UV/vis, fluorescence spectroscopy, DNA viscosity, and molecular docking) suggested that these new derivatives significantly intercalate between two strands of DNA. In addition, the most potent derivatives 4a and 4b were also found to inhibit DNA topoisomerase-II.

Synthesis and biological evaluation of 1-benzyl-N-(2-(phenylamino)pyridin-3-yl)-1H-1,2,3-triazole-4-carboxamides as antimitotic agents.

A library of 1-benzyl-N-(2-(phenylamino)pyridin-3-yl)-1H-1,2,3-triazole-4-carboxamides (7a-al) have been designed, synthesized and screened for their anti-proliferative activity against some selected human cancer cell lines namely DU-145, A-549, MCF-7 and HeLa. Most of them have shown promising cytotoxicity against lung cancer cell line (A549), amongst them 7f was found to be the most potent anti-proliferative congener. Furthermore, 7f exhibited comparable tubulin polymerization inhibition (IC50 value 2.04 µM) to the standard E7010 (IC50 value 2.15 µM). Moreover, flow cytometric analysis revealed that this compound induced apoptosis via cell cycle arrest at G2/M phase in A549 cells. Induction of apoptosis was further observed by examining the mitochondrial membrane potential and was also confirmed by Hoechst staining as well as Annexin V-FITC assays. Furthermore, molecular docking studies indicated that compound 7f binds to the colchicine binding site of the ß-tubulin. Thus, 7f exhibits anti-proliferative properties by inhibiting the tubulin polymerization through the binding at the colchicine active site and by induction of apoptosis.

Synthesis and biological evaluation of Schizandrin derivatives as potential anti-cancer agents.

A new series of Schizandrin (1) derivatives were synthesized utilizing the C-9 position of the Schizandrin core and evaluated for their cytotoxic activities against HeLa (cervical cancer), A549 (lung cancer), MCF-7 (breast cancer) and DU-145 (prostate cancer) cell lines. Among the synthesized series, 4e, 4f, 4g and 5 showed potent activities against tested cell lines. More significantly, compound 5 exhibited most potent cytotoxic activity against DU-145 with an IC50 value of 1.38 µM which is comparable to the standard agent, doxorubicin. Further, flow cytometry analysis indicated that 5 arrested cells in G2/M phase and consequently leading to apoptosis. Molecular docking analysis showed that 5 occupied the colchicine binding pocket of tubulin. Overall, the present study demonstrates that 5, as a mitotic-agent.

Design, synthesis and biological evaluation of imidazopyridine-propenone conjugates as potent tubulin inhibitors.

A library of imidazopyridine-propenone conjugates (8a-8u) were synthesized and evaluated for their antitumor activity against four human cancer cell lines, namely, prostate (DU-145), lung (A549), cervical (Hela) and breast (MCF-7) cancer cell lines. These conjugates showed good to moderate activity against the tested cell lines. Among them, two conjugates (8m and 8q) showed significant antiproliferative activity against the human lung cancer cell line (A549) with IC50 values of 0.86 µM and 0.93 µM, respectively. Flow cytometry analysis revealed that these compounds arrested the cell cycle at the G2/M phase in the human lung cancer cell line (A549), inhibiting tubulin polymerization leading to apoptosis. Further, Hoechst staining, decrease in mitochondrial membrane potential and Annexin V-FITC assay suggested that the cell death was due to apoptosis induction. Overall, the present investigation demonstrated that the synthesized imidazopyridine-propenone conjugates are promising tubulin inhibitors and apoptotic inducers.

Click chemistry-assisted synthesis of triazolo linked podophyllotoxin conjugates as tubulin polymerization inhibitors.

A series of new triazolo linked 4ß-amidopodophyllotoxin conjugates (9a-l) were synthesized using click chemistry and evaluated for their antitumor activity against four human cancer cell lines. Among them, two compounds (9c and 9j) showed significant anticancer activity with IC50 values of 0.9 and 0.07 µM, respectively. Biological studies are conducted into the cell-cycle distribution of these conjugates inducing G2/M-phase arrest, apart from an increase in the levels of caspase-3 proteins, followed by apoptotic cell death. A tubulin polymerization assay analysis showed that these compounds effectively inhibit microtubule assembly in HeLa cells and, moreover, Hoechst 33258 and Immunohistochemistry staining suggest that these compounds induce cell death by apoptosis. The docking studies showed that compounds 9c and 9j interact and bind efficiently with the tubulin protein at the colchicine site.

Synthesis and biological evaluation of cis-restricted triazole/tetrazole mimics of combretastatin-benzothiazole hybrids as tubulin polymerization inhibitors and apoptosis inducers.

A series of colchicine site binding tubulin inhibitors were synthesized by the modification of the combretastatin pharmacophore. The ring B was replaced by the pharmacologically relevant benzothiazole scaffolds, and the cis configuration of the olefinic bond was restricted by the incorporation of a triazole and tetrazole rings which is envisaged by the structural resemblance to a tubulin inhibitor like combretastatin (CA-4). These compounds were evaluated for their antiproliferative activity on selected cancer cell lines and an insight in the structure activity relationship was developed. The most potent compounds (9a and 9b) demonstrated an antiproliferative effect comparable to that of CA-4. Mitotic cell cycle arrest in G2/M phase revealed the disruption of microtubule dynamics that was confirmed by tubulin polymerization assays and immunocytochemistry studies at the cellular level. Western blot analysis revealed that these compounds accumulate more tubulin in the soluble fraction. The colchicine competitive binding assay and the molecular docking studies suggested that the binding of these mimics at the colchicine site of the tubulin is similar to that of CA-4. Moreover, the triggering of apoptotic cell death after mitotic arrest was investigated by studying their effect by Hoechst staining, Annexin-V-FITC assay, mitochondrial membrane potential, ROS generation and caspase-3 activation.

Design, synthesis and biological evaluation of N-((1-benzyl-1H-1,2,3-triazol-4-yl)methyl)-1,3-diphenyl-1H-pyrazole-4-carboxamides as CDK1/Cdc2 inhibitors.

A series of new (N-((1-benzyl-1H-1,2,3-triazol-4-yl)methyl)-1,3-diphenyl-1H-pyrazole-4-carboxamide derivatives (8-35) were designed, synthesized and evaluated as CDK1/Cdc2 inhibitors. Biological evaluation assays indicated that compounds 16 and 27 showed the most potent growth inhibitory activity against human cancer cell lines (MIAPaCa-2, MCF-7 and HeLa) with GI50 values ranging from 0.13 to 0.7 µM, compared with the positive control nocodazole (0.81-0.95 µM). Flow cytometric analysis revealed that these compounds induce cell cycle arrest in the G2/M phase and Western blot analysis suggested that compound treatment resulted in reduction of CDK1 expression levels in MCF-7 cell line. Moreover, the apoptosis inducing effect of the compounds was studied using Hoechst staining, Rhodamine 123 staining (MMP), carboxy-DCFDA staining (ROS), Annexin V-FITC assay. Based on these studies, two compounds 16 and 27 have been identified as promising new molecules that have the potential to be developed as leads.

Benzo[b]furan derivatives induces apoptosis by targeting the PI3K/Akt/mTOR signaling pathway in human breast cancer cells.

The PI3K/Akt/mTOR signaling pathway plays a key regulatory function in cell survival, proliferation, migration, metabolism and apoptosis. Aberrant activation of the PI3K/Akt/mTOR pathway is found in many types of cancer and thus plays a major role in breast cancer cell proliferation. In our previous studies, benzo[b]furan derivatives were evaluated for their anticancer activity and the lead compounds identified were 26 and 36. These observations prompted us to investigate the molecular mechanism and apoptotic pathway of these lead molecules against breast cancer cells. Benzo[b]furan derivatives (26 and 36) were evaluated for their antiproliferative activity against human breast cancer cell lines MCF-7 and MDA MB-231. These compounds (26 and 36) have shown potent efficiency against breast cancer cells (MCF-7) with IC50 values 0.057 and 0.051µM respectively. Cell cycle analysis revealed that these compounds induced cell cycle arrest at G2/M phase in MCF-7 cells. Western blot analysis revealed that these compounds inhibit the PI3K/Akt/mTOR signaling pathway and induced mitochondrial mediated apoptosis in human breast cancer cells (MCF-7).

Synthesis and biological evaluation of cinnamido linked benzophenone hybrids as tubulin polymerization inhibitors and apoptosis inducing agents.

A new class of hybrid molecules containing cinnamide subunit linked to benzophenone as inhibitors of tubulin polymerization were synthesized and evaluated for their anticancer potential. These hybrids exhibit anticancer activity with IC50 values ranging from 0.06 to 16.3µM. Compounds 4f and 4g possessing fluoro and trifluoromethyl on the cinnamido subunit showed significant cytotoxic activity with IC50 values 0.06 and 0.09µM against HeLa cell line, respectively. These compounds showed cell cycle arrest at G2/M phase of the cell cycle and inhibited tubulin polymerization followed by activation of caspase-3 activity and apoptotic cell death. Further in vitro tubulin polymerization assay showed that the level of tubulin inhibition was comparable to that of 2a for the compounds 4f and 4g. Moreover, Hoechst 33258 staining and DNA fragmentation assay suggested that these compounds induce cell death by apoptosis. Overall, the current study demonstrates that the synthesis of benzophenone linked cinnamide subunit conjugates as promising anticancer agents with G2/M arrest and apoptotic-inducing ability via targeting tubulin.

Synthesis and selective cytotoxic activity of novel hybrid chalcones against prostate cancer cells.

A new class of hybrid chalcones (17a-l &18a-l) was synthesized by Claisen-Schmidt condensation. All compounds were characterized by (1)H NMR, IR and mass spectral analysis and tested for their cytotoxic activity against PC-3 (prostate cancer), HT-29 (colon cancer), B-16 (mouse macrophages) and NCI-H460 (lung cancer) cell lines. Three compounds 18i, 18j and 18l (IC(50)=8.4, 7.9 & 5.9 µM) showed significant activity against PC-3 cell line.

Synthesis of chalcone-amidobenzothiazole conjugates as antimitotic and apoptotic inducing agents.

A series of chalcone-amidobenzothiazole conjugates (9a-k and 10a,b) have been synthesized and evaluated for their anticancer activity. All these compounds exhibited potent activity and the IC(50) of two potential compounds (9a and 9f) against different cancer cell lines are in the range of 0.85-3.3 µM. Flow cytometric analysis revealed that these compounds induced cell cycle arrest at G2/M phase in A549 cell line leading to caspase-3 dependent apoptotic cell death. The tubulin polymerization assay (IC(50) of 9a is 3.5 µM and 9f is 5.2 µM) and immuofluorescence analysis showed that these compounds effectively inhibit microtubule assembly at both molecular and cellular levels in A549 cells. Further, Annexin staining also suggested that these compounds induced cell death by apoptosis. Moreover, docking experiments have shown that they interact and bind efficiently with tubulin protein. Overall, the current study demonstrates that the synthesis of chalcone-amidobenzothiazole conjugates as promising anticancer agents with potent G2/M arrest and apoptotic-inducing activities via targeting tubulin.

Design and synthesis of benzo[c,d]indolone-pyrrolobenzodiazepine conjugates as potential anticancer agents.

A series of benzo[c,d]indol-2(1H)one-PBD conjugates (11a-l) have been designed and synthesized as potential anticancer agents. These compounds were prepared by linking the C8-position of DC-81 with a benzo[c,d]indol-2(1H)one moiety through different alkane spacers in good yields and confirmed by (1)H NMR, mass and HRMS data. The DNA binding ability of these conjugates was evaluated by thermal denaturation studies and interestingly, compound 11l showed enhanced DNA binding ability. These compounds were also evaluated for their anticancer activity in selected human cancer cell lines of lung, skin, colon and prostate by using MTT assay method. These new conjugates showed promising anticancer activity with IC(50) values ranging from 1.05 to 36.49 µM. Moreover, cell cycle arrest in SubG1 phase was observed upon treatment of A549 cells with 1 and 2 µM (IC(50)) concentrations of compound 11l and it induced apoptosis. This is confirmed by Annexin V-FITC, Hoechst staining, caspase-3 activity as well as DNA fragmentation analysis.

Synthesis and anticancer activity of 4ß-alkylamidochalcone and 4ß-cinnamido linked podophyllotoxins as apoptotic inducing agents.

A series of 4ß-alkylamidochalcone and 4ß-cinnamido linked podophyllotoxin congeners have been synthesized. All the twenty nine compounds were evaluated for anticancer activity against five human cancer cell lines (A-549, A375, MCF-7, HT-29 and ACHN). Some of the synthesized compounds showed good anticancer activity that is comparable to etoposide. The IC(50) of compounds 17a and 17f is 2.7 and 2.1 µM respectively against A-549 cancer cell line. Flow cytometric analysis showed that these two compounds arrested the cell cycle in the G2/M phase leading to caspase-3 dependent apoptotic cell death. Further, Hoechst 33258 staining and DNA fragmentation assay also suggested that 17a and 17f induced cell death by apoptosis.