Antioxidative and anti-proliferative potential of Curculigo orchioides Gaertn in oxidative stress induced cytotoxicity: In vitro, ex vivo and in silico studies.

Plant phytoconstituents have been a valuable source of clinically important anticancer agents. Antioxidant and anticancerous activity of plant Curculigo orchioides Gaertn were explored In vitro antioxidant activity, antioxidant enzyme activity of oxidatively stressed tissue, and cell culture studies on human cancer cell lines HepG2, HeLa and MCF-7 were carried out. Active plant fractions were subjected to GC-MS analysis and compounds selected on the basis of their abundance were screened in silico with the help of Auto Dock 4.2 tools with pre-selected antioxidant enzymes. Curculigo orchioides Gaertn plant fractions exhibited significant antioxidant activities by virtue of scavenging of free radicals having IC50 value of ethylacetate fraction (EA) for DPPH radical scavenging assay to be 52.93 ±â€¯0.66 µg/ml. Further, antioxidant enzyme defense of mammalian tissue when treated with plant fractions revealed that enzyme concentrations were refurbished which were increased during oxidative stress. MTT assay on cell lines HepG2, HeLa and MCF-7 presented IC50 values of ethylacetate (EA) fraction as 171.23 ±â€¯2.1 µg/ml, 144.80 ±â€¯1.08 µg/ml and 153.51 µg/ml and aqueous ethylacetate (AEA) fraction as 133.44 ±â€¯1.1 µg/ml, 136.50 ±â€¯0.8 µg/ml and 145.09 µg/ml respectively. Further EA and AEA plant fractions down regulated the levels of antiapoptotic Bcl-2 expression and upregulated the expression of apoptotic proteins caspase-3 and caspase-8 through an intrinsic ROS-mediated mitochondrial dysfunction pathway. KEY MESSAGE: Key findings explained that fractions of Curculigo orchioides Gaertn inhibited oxidative stress by increasing the antioxidant enzyme content and have anticancerous potential on cancer cell lines HepG2, HeLa and MCF-7.

Piperazine clubbed with 2-azetidinone derivatives suppresses proliferation, migration and induces apoptosis in human cervical cancer HeLa cells through oxidative stress mediated intrinsic mitochondrial pathway.

Piperazine scaffolds or 2-azetidinone pharmacophores have been reported to show anti-cancer activities and apoptosis induction in different types of cancer cells. However, the mechanistic studies involve in induction of apoptosis addressing these two moieties for human cervical cancer cells remain uncertain. The present study emphasizes on the anti-proliferating properties and mechanism involved in induction of apoptosis for these structurally related azoles derivatives in HeLa cancer cells. 1-Phenylpiperazine clubbed with 2-azetidione derivatives (5a-5h) were synthesized, characterized using various spectroscopic techniques and evaluated for their in-vitro anti-proliferative activities and induction of apoptosis. Further, we also evaluated oxidative stress generated by these synthetic derivatives (5a-5h). Cell viability studies revealed that among all, the compound N-(3-chloro-2-(3-nitrophenyl)-4-oxoazetidin-1-yl)-2-(4-phenylpiperazin-1-yl) acetamide 5e remarkably inhibited the growth of HeLa cells in a concentration dependent manner having IC50 value of 29.44 ± 1.46 µg/ml. Morphological changes, colonies suppression and inhibition of migration clearly showed the antineoplasicity in HeLa cells treated with 5e. Simultaneously, phosphatidylserine externalization, DNA fragmentation and cell-cycle arrest showed ongoing apoptosis in the HeLa cancer cells induced by compound 5e in concentration dependent manner. Additionally, generation of intracellular ROS along with the decrease in mitochondrial membrane potential supported that compound 5e caused oxidative stress resulting in apoptosis through mitochondria mediated pathway. Elevation in the level of cytochrome c and upregulation in expression of caspase-3 clearly indicated the involvement of the intrinsic pathway of programmed cell death. In brief; compound 5e could serve as a promising lead for the development of an effective antitumor agent.

Inhibitory growth evaluation and apoptosis induction in MCF-7 cancer cells by new 5-aryl-2-butylthio-1,3,4-oxadiazole derivatives.

BACKGROUND: Cancer has become one of the global health issues and it is the life-threatening disease characterized by unrestrained growth of cells. Despite various advances being adopted by chemotherapeutic management, the use of the current anticancer drugs such as Doxorubicin, Asparginase, Methotrexate, Vincristine remains limited due to high toxicity, side effects and developing drug resistance. Apoptosis is a crucial cellular process and improper regulation of apoptotic signaling pathways may lead to cancer formation. Subsequently, the synthesis of effective chemotherapeutic agents that can induce apoptosis in tumor cell has emerged as a significant approach in cancer drug discovery. METHODS: The goal of this work is to develop a potential antitumor agent exerting significant inhibitory effects on cancer cell and low cytotoxicity, for which we focused on the structural features of 1,3,4-oxadiazoles as it a privileged scaffold in modern medicinal chemistry and have the ability to inhibit growth factors, enzymes and kinases potentially involved in the attainment of cellular immortality and carcinogenesis. RESULT: In vitro MTT screening assay showed the compound 5-aminophenyl-2-butylthio-1,3,4-oxadiazole (5e) showing the highest inhibitory effect against MCF-7 cancer cell with IC50 value 10.05 ± 1.08 µM while it is much safer and less toxic on normal cell line (HEK-293). The dose-dependent treatment of MCF-7 cells with 5e resulted in inhibition of cell migration in the wound healing assay. The flow-cytometry analysis showed the cells arrested in G0/G1 phase of the cell cycle. Compound 5e induced apoptosis of MCF-7 cells was characterized using DAPI staining and Annexin V-PE/7-AAD dual binding assay. Reduction of NBT by compound 5e showed a reduced generation of ROS. Western blotting studies showed high activation of apoptotic protein Caspase3 and decrease in expression of anti-apoptotic protein BCL-2. CONCLUSION: Based on the results of in vitro studies, it could be concluded that compound 5e showed a significant inhibitory growth effect on MCF-7 cells and have the potential to be developed as lead molecule and further structural modifications may result in promising new anticancer agents.

New insights into the antioxidant and apoptotic potential of Glycyrrhiza glabra L. during hydrogen peroxide mediated oxidative stress: An in vitro and in silico evaluation.

Plant-derived substances (phytochemicals) are well recognized as sources of pharmacologically potent drugs in the treatment of several oxidative stress related disorders. Our study aims to evaluate the antioxidant and apoptotic effects of Glycyrrhiza glabra L. in both cell free and cell culture system. Plant fractions have been prepared with hexane, chloroform, ethyl acetate, methanol and water and their antioxidant properties are reviewed. Potent antioxidant activity has been well established in both in vitro and in silico studies which is believed to be responsible for the anticancerous nature of the plant. Results obtained indicate that methanol fraction of G. glabra L. exhibited maximum scavenging activity against DPPH and nitric oxide free radicals comparable to standard antioxidant L-AA. Administration of methanol fraction also considerably reduced the malondialdehyde produced due to lipid peroxidation in mammalian liver tissues. Moreover, the levels of antioxidant enzymes SOD, CAT, GST, GPx and GR in the oxidative stress induced tissues were refurbished significantly after treatment with plant's methanol fraction. Moreover, methanol fraction was found to be nontoxic to normal human cell line whereas it inhibited cancer cells HeLa and HepG2 considerably. Apoptosis was established by DAPI fluorescent staining and western blot analysis of pro apoptotic protein caspase-8, caspase-3 and anti-apoptotic protein Bcl-2.There is an up regulation in the levels of pro apoptotic caspase-8 and caspase-3 and down regulation of anti-apoptotic Bcl-2. Furthermore, GC-MS analysis of the methanol fraction revealed the presence of many compounds. In silico experiments using Autodock 4.2 tools showed strong affinity of plant compounds towards antioxidant enzymes (proteins) thus validating with the conclusions of antioxidant enzyme assays and establishing a role in cancer pathogenesis.

Synthesis, characterization and anticancer screening of some novel piperonyl-tetrazole derivatives.

A series of new 1,2-substituted tetrazole derivatives were synthesized and evaluated on MCF-7 (ER positive), MDA-MB-231 and ZR-75 (ER negative) breast cancer cell lines. Out of the fourteen compounds, three compounds 10, 12 and 14 showed higher inhibitory effects on MCF-7 cells. Whereas, compound 8 exhibited higher inhibition in MDA-MB-231 and ZR-75 cells at 10(-5) M concentration. Total RNA was extracted and effect of compounds on different marker genes was studied. The gene expression of CD44, BRAC and BAX were significantly affected. The compounds were screened against the HepG2 cell line, to know if they are selectively targeting specific cancers and only 1-10 percent inhibition was found at 10(-5) M concentration.

Synthesis and in vitro evaluation of novel tetrazole embedded 1,3,5-trisubstituted pyrazoline derivatives as Entamoeba histolytica growth inhibitors.

A series of pyrazoline derivatives (1a-15a) was synthesized by cyclization of chalcones (1-15) with 2-[5-(4-methoxyphenyl)-1H-tetrazol-1-yl]acetohydrazide under basic conditions and were screened in vitro, to find out effect on the growth of HM1: IMSS strain of Entamoeba histolytica. The compounds 3a, 4a, 11a, 13a and 14a showed encouraging results with IC(50) value in the range of 0.86-1.28 µM. However compound 13a showed most promising results with IC(50) = 0.86 µM which is half of the metronidazole, the standard drug used for protozoal infection. Cell viability test in human hepatocellular carcinoma cell line (HepG2) revealed non-toxic nature of new synthesized compounds. Safety index calculations prevailed compound 13a as highly antiamoebic and least cytotoxic (S.I. = >116.28), almost twice than metronidazole.

Probing the antiamoebic and cytotoxicity potency of novel tetrazole and triazine derivatives.

A series of compounds bearing a Tetrazole and Triazine ring motif conjugated with a SO(2)NH function were synthesized and investigated for their antiamoebic potency. Cytotoxicity of the compounds was checked on human hepatocellular carcinoma cell line HepG2. Incorporation of Triazine ring in place of tetrazole resulted in a precipitous increase in the antiamoebic activity of the compounds. Antiamoebic activity of the investigated compounds was found to be position and substituent dependent. In vitro cytotoxicity results revealed noncytotoxic nature of all the tested compounds up to a concentration of 25 µM. Compound 5c and 5d were obtained as least cytotoxic (IC(50) > 100 µM) and excellent Entamoeba histolytica inhibitors with IC(50) values of 1.05 µM and 1.02 µM respectively.

Synthesis, characterization, antiamoebic activity and toxicity of novel bisdioxazole derivatives.

Cyclization of benzene-1,4-dicarbaldehyde dioxime 1 with different aromatic aldehydes in inert atmosphere yielded the corresponding new bisdioxazoles 2-11. The structure of 2-11 was elucidated by spectral data. In vitro antiamoebic activity was performed against HM1:IMSS strain of Entamoeba histolytica. The results showed that the compounds 3 (IC(50)=1.22 microM), 4 (IC(50)=1.41 microM), 7 (IC(50)=1.05 microM) and 10 (IC(50)=1.01 microM) exhibited better antiamoebic activity than the standard drug metronidazole (IC(50)=1.80 microM). The compounds 3, 4, 7 and 10 were tested for toxicity by MTT assay on H9c2 cardiac myoblasts and the results showed that the compounds 3, 4, 7 and 10 offered remarkable viability of 96.2%, 83.5%, 82% and 89%, respectively at a concentration of 12.5 microg/ml.

Synthesis, spectral studies and antiamoebic activity of new 1-N-substituted thiocarbamoyl-3-phenyl-2-pyrazolines.

Thirty new pyrazoline derivatives were synthesized by cyclization of Mannich bases with thiosemicarbazides being substituted by different cyclic and aromatic amines. The structures of the compounds were elucidated by elemental analyses, UV, IR, (1)H and (13)C NMR and ESI-MS spectral data. The in vitro antiamoebic activity was evaluated against Entamoeba histolytica in comparison with metronidazole used as reference substance. Out of the 30 compounds screened for antiamoebic activity, 10 (5, 6, 15, 18, 25-30) were found to be better inhibitors of E. histolytica since they showed lesser IC(50) values than metronidazole. The preliminary results indicated that the presence of 3-chloro or 3-bromo substituent on the phenyl ring at position 3 of the pyrazoline ring enhanced the antiamoebic activity as compared to unsubstituted phenyl ring. The study suggests that the preliminary activity of these compounds may further be explored for the development of new targets for amoebiasis.

Synthesis of new 2-(5-substituted-3-phenyl-2-pyrazolinyl)-1,3-thiazolino[5,4-b]quinoxaline derivatives and evaluation of their antiamoebic activity.

In an effort to develop potent antiamoebic agents, we have synthesized chalcones (1-8), amino-5-substituted-(3-phenyl(2-pyrazolinyl))methane-1-thione derivatives (1a-8a) and 2-(5-substituted-3-phenyl-2-pyrazolinyl)-1,3-thiazolino[5,4-b]quinoxaline derivatives (1b-8b) and evaluated for their in vitro antiamoebic activity against HM1:IMSS strain of E. histolytica. All the compounds were characterized by electronic, IR, (1)H NMR and mass spectroscopic data. It was observed that the antiamoebic activity enhances on modifying the structure of chalcones to the pyrazolines and further to quinoxalines. The MTT assay was performed on human kidney epithelial cell line to check the cytotoxicity of the compounds and the results were compared with metronidazole. Compound 6b showed better antiamoebic activity and less toxicity than metronidazole.

Antiamoebic coumarins from the root bark of Adina cordifolia and their new thiosemicarbazone derivatives.

In continuation of our search for potential antiamoebic agents from folklore Indian medicinal plants, we found that the benzene and ethyl acetate extracts from the root bark of Adina cordifolia exhibited strong antiamoebic activity with IC(50) values of 2.92 and 2.50 microg/ml, respectively. Bioassay-guided fractionation of benzene and ethyl acetate extracts led to the isolation of 7-hydroxycoumarin (umbelliferone 1) and 7-beta-D-glucosylcoumarin (skimmin 2), respectively. Umbelliferone 1 was converted into 7-acetoxycoumarin 1a, which on treatment with aluminium chloride afforded 7-hydroxy-8-acetylcoumarin 2a. A new series of thiosemicarbazones 3a-e of 7-hydroxy-8-acetylcoumarin with different thiosemicarbazides were synthesized. Umbelliferone was also converted into its methoxy derivative (7-methoxycoumarin 4). Subsequently, all the compounds were assessed for antiamoebic activity against HM1:IMMS strain of Entamoeba histolytica. Umbelliferone and skimmin were found to possess a very good activity with IC(50) values of 6.38 and 4.35 microM/ml, respectively. The activity drastically increased on converting compound 2a into its thiosemicarbazone derivatives 3a-e with IC(50) values ranging between 1.06 and 4.46 microM/ml. Compounds 3b,c and e with IC(50) values of 1.49, 1.56 and 1.06 microM/ml, respectively, exhibited even higher antiamoebic activity than the standard drug metronidazole (IC(50)=2.62 microg/ml). The activity of 7-methoxycoumarin (IC(50)=8.92 microM/ml) was less than umbelliferone. Compounds 3b, c and e were tested for toxicity using H9c2 cardiac myoblasts cell line. The compounds exhibit >80% viability at 3.125-200 microg/ml. It is apparent from these results that umbelliferone and skimmin may be a useful lead for the development of new antiamoebic drugs.

New Pd(II) complexes of the synthesized 1-N-substituted thiosemicarbazones of 3-indole carboxaldehyde: characterization and antiamoebic assessment against E. histolytica.

Reaction of 3-indole carboxaldehyde with aminothiocarbonyl hydrazines resulted in the formation of 3-indole carboxaldehyde thiosemicarbazones (TSCs) 1-13. The synthesized thiosemicarbazones were used as ligands in the formation of [Pd(TSC)Cl2] complexes with palladium(II) metal ion precursor, [Pd(DMSO)2Cl2]. The chemical structures of all the compounds were established by electronic, IR, 1H NMR and 13C NMR spectral data. The structure of the complexes was further established by FABMS and DTA. It is concluded that the thione sulphur and the azomethine nitrogen atom of the ligands are bonded to the metal ion. The testing of the antiamoebic activity of these compounds against the protozoan parasite Entamoeba histolytica suggests that compounds 5, 3a, 5a and 8a-13a might be endowed with important antiamoebic properties since they showed less IC50 values than metronidazole. Moreover, compound 12a displays remarkable antiamoebic activity than metronidazole (IC50 values of 0.29 vs 1.81 microM, respectively). MTT assay showed that the compounds are non-toxic to human kidney epithelial cell line.