Identifying the alpha-glucosidase inhibitory potential of dietary phytochemicals against diabetes mellitus type 2 via molecular interactions and dynamics simulation.

The research aims to identify the inhibitory potential of natural dietary phytochemicals against non-insulinotropic target protein alpha-glucosidase and its possible implications to diabetes mellitus type 2. A data set of sixteen plant-derived dietary molecules viz., 4,5-dimethyl-3-hydroxy-2(5H)-furanone, apigenin, bromelain, caffeic acid, cholecalciferol, dihydrokaempferol 7-o-glucopyranoside, galactomannan, genkwanin, isoimperatorin, luteolin, luteolin 7-o-glucoside, neohesperidin, oleanoic acid, pelargonidin-3-rutinoside, quercetin, and quinic acid were taken to accomplish molecular docking succeeded by their comparison with known inhibitors including acarbose, miglitol, voglibose, emiglitate, and 1-deoxynojirimycin. Among all phyto-compounds, bromelain (ΔG: -9.54 kcal/mol), cholecalciferol (-8.47 kcal/mol), luteolin (-9.02 kcal/mol), and neohesperidin (-8.53 kcal/mol) demonstrated better binding interactions with alpha-glucosidase in comparison to the best-known inhibitor, acarbose (ΔG: -7.93 kcal/mol). Molecular dynamics simulation of 10 ns duration, CYP450 site of metabolism identification, and prediction of activity spectra for substances depicted the bromelain as the most stable inhibitor compared to luteolin and acarbose. Findings of molecular interactions, molecular dynamics study, metabolism, and biological activity prediction proved bromelain as a potential alpha-glucosidase inhibitor. Thus, bromelain might be helpful as an insulin-independent therapeutic molecule towards controlling and managing diabetes mellitus type 2.

Molecular Mechanism of Cancer Susceptibility Associated with Fok1 Single Nucleotide Polymorphism of VDR in Relation to Breast Cancer

Breast cancer is the leading cause of death among women worldwide. It is a multi-factorial disease caused by genetic and environmental factors. Vitamin D has been hypothesized to lower the risk of breast cancer via the nuclear vitamin D receptor (VDR). Genetic variants of these vitamin D metabolizing genes may alter the bioavailability of vitamin D, and hence modulate the risk of breast cancer. Materials and Methods: The distribution of Fok1 VDR gene (rs2228570) polymorphism and its association with breast cancer was analysed in a case­control study based on 125 breast cancer patients and 125 healthy females from North Indian population, using PCR-RFLP. An In silico exploration of the probable mechanism of increased risk of breast cancer was performed to investigate the role of single nucleotide polymorphisms (SNPs) in cancer susceptibility. Results: The Fok1 ff genotype was significantly associated with an increased risk of breast cancer (p=0.001; χ2=13.09; OR=16.909; %95 CI=2.20 - 130.11). In silico analysis indicated that SNPs may lead to a loss in affinity of VDR to calcitriol, and may also cause the impairment of normal interaction of liganded VDR with its heterodimeric partner, the retinoid X receptor (RXR), at protein level, thereby affecting target gene transcription. Conclusion: Breast cancer risk and pathogenesis in females can be influenced by SNPs. SNPs in VDR may cause alterations in the major molecular actions of VDR, namely ligand binding, heterodimerization and transactivation. VDRE binding and co-activator recruitment by VDR appear to be functionally inseparable events that affect vitamin D-elicited gene transcription. This indicates that breast cancer risk and pathogenesis in females may be influenced by SNPs.

Molecular Interaction and Computational Analytical Studies of Pinocembrin for its Antiangiogenic Potential Targeting VEGFR-2: A Persuader of Metastasis.

BACKGROUND: Designing a novel antagonist against VEGFR-2 is being applied currently to inhibit cancer growth and metastasis. Because of the unexpected side effects incurred by the contemporary anticancer medications, the focus has been laid towards identifying natural compounds that might carry the potential to inhibit tumor progression. VEGR-2 remains an important target for anticancer drug development as it is the master regulator of vascular growth. OBJECTIVE: The study focuses on virtual screening of compounds from plants of Asteraceae family that bears antiangiogenic potential and thus, inhibiting VEGFR-2 using a computational approach. MATERIALS AND METHODS: Structures of phytochemicals were prepared using ChemDraw Ultra 10 software and converted into its 3D PDB structure and minimized using Discovery Studio client 2.5. The target protein, VEGFR-2 was retrieved from RCSB PDB. Lipinski's rule and ADMET toxicity profiling were carried out on the phytochemicals of the Asteraceae family and the filtered compounds were further promoted for molecular docking and MD simulation analysis. The study extends towards the SOM analysis of Pinocembrin to predict the possible toxic and non-toxic in vivo metabolites via in silico tools (Xenosite Web and PASS online server). RESULTS: The docking results revealed promising inhibitory potential of Pinocembrin against VEGFR-2 with binding energy of -8.50 kcal/mole as compared to its known inhibitors Sorafenib and YLT192 having binding energy of -6.49 kcal/mole and -8.02 kcal/mol respectively. Further, molecular dynamics (MD) simulations for 10ns were conducted for optimization, flexibility prediction, and determination of folded VEGFR-2 stability. The Hsp90-Pinocembrin complex was found to be quite stable with RMSD value of 0.2nm. Pinocembrin was found to be metabolically stable undergoing phase I metabolism with non-toxic metabolites compared to the standard drug Sorafenib and YLT192. CONCLUSION: Obtained results propose Pinocembrin as a multi-targeted novel lead compound that bears outstanding antiangiogenic potential against VEGFR-2.

Structural Insight into the Mechanism of Dibenzo[a,l]pyrene and Benzo[a]pyrene-Mediated Cell Proliferation Using Molecular Docking Simulations.

In the proposed work, we have explicated the mechanism of dibenzo[a,l]pyrene (DBP) and benzo[a]pyrene (BP) modulated cell proliferation by assessing the plausible binding with CASPASES, BAX, Bcl-2, MDM2, p53, p21, p16, CylinD1-CDK4 complex, CylinE1-CDK2 complex, H-Ras, K-Ras, BRCA1, and BRCA2 through exploiting the inherent potential of AutoDock Tools 4.0. In silico findings revealed that potent carcinogenic metabolites of DBP (e.g., (-)-anti-DBPDE and (+)-syn-DBPDE) and BP (e.g., (+)-anti-BPDE) exhibited better binding interactions to Caspase-9 than Caspase-8 and Caspase-3. Feeble interactions of BAX and Bcl-2 with diol-epoxides of both PAHs were observed. Diol-epoxides of DBP and BP were found to bind to p53 with tighter interaction than MDM2 and p53-MDM2 complex. The p16 and Cyclin-CDK complexes were best docked to aforesaid metabolites as compared to p21. Moreover, stronger interactions of BRCA1 and BRCA2 with DBP and feeble interactions of BRCA1 and BRCA2 with BP were observed from docking results. Furthermore, stronger interactions of both DBP and BP with the H-Ras and K-Ras oncoproteins were found, while only DBP interacted relatively strongly with the BRCA1 and BRCA2, which were suggesting more carcinogenic nature of DBP than BP, a well-known observation in the wet lab. Besides giving structural insight into the mechanism of DBP and BP-mediated cell proliferation, these in silico findings may be helpful to understand the mechanistic nature of environmental carcinogens and their cellular targets.

Marine Drugs: A Hidden Wealth and a New Epoch for Cancer Management.

BACKGROUND: Malignant tumors are the leading cause of death in humans. Due to the tedious efforts and investigations made in the field of marine drug discovery, there is now a scientific bridge between marine and pharmaceutical sciences. However, currently only few marine drugs have been lined towards anticancer direction yet many more to are be established in future as well. METHOD: This review gives an overview of present status of marine natural products MNPs both at the level of research and clinical stages. The authors haved summarized the detail information of diverse marine organisms that were reportedto be active or potentially active in cancer treatment in the last two decades. Interstingly, marine organisms are abundant producer of plenty of structurally incomparable bioactive metabolites that have unusual mode of actions and diverse biosynthetic pathways. RESULTS: This review summarizes the associated anticancer properties of different classes of marine natural compounds based on their structural diversity, biological activity, and the molecular mechanisms of action. Emphasis has also be given to recent advances in clinical development of marine agents used in clinical trials. CONCLUSIONS: The present review is summarising the various sources of marine chemicals and their exploration of anticancerous potential. There is justified hope for the discovery and development of new anticancer agents from the marine environment.

Evaluation and Elucidation Studies of Natural Aglycones for Anticancer Potential using Apoptosis-Related Markers: An In silico Study.

Exposure to exogenous and endogenous chemicals and subsequent cellular and molecular changes has been linked to enhanced cell proliferation and restricted apoptosis phenomenon. Though in the past decades numerous anticancer drugs inducing programmed cell death in cancer cells by targeting specific apoptotic markers have reached the market, they have been allied with unwanted side effects, ranging from mild to severe toxicity. With further understanding on the functional mechanism of p53 and MDM2 in apoptosis and in our continuous search for new and potent multi-target anticancer lead compounds, we have carried out molecular docking and inhibition studies of the selected aglycones along with selected anticancer leads, against the specific apoptotic and cell cycle markers using AutoDock Tools 4.0 and other computational softwares. The docking results have been analyzed in terms of binding energies (kcal/mol) and inhibition constant (µM). The study clearly proposes our aglycones [solanidine (Solanid-5-en-3ß-ol), solasodine (Solasod-5-en-3ß-ol), and tomatidine (5α-Tomatidan-3ß-ol)] induce apoptosis by inhibiting the p53-MDM2 complex, p21Waf1/Cip1, and Bcl-2 proteins, which were even found comparable with the anticancer drugs nutlin and/or halofuginone. The work further emphasizes that the individual molecular targets such as BAX and Bcl-2 may result in misleading data at any level; however, ratio of responses to BAX and Bcl-2 shall be considered for better clue about a compound to be pro- or anti-apoptotic.

Development of In Silico Protocols to Predict Structural Insights into the Metabolic Activation Pathways of Xenobiotics.

To establish in silico model to predict the structural insight into the metabolic bioactivation pathway of xenobiotics, we considered two specific and one non-specific mammary procarcinogen [e.g., dibenzo[a,l]pyrene (DBP), 7,12-dimethylbenz[a]anthracene (DMBA), and benzo[a]pyrene (BP)]. The CYP1A1, 1B1, 2C9, 1A2 and 2B6 reported in wet-lab studies to actively metabolize DBP also showed strong binding energies (kcal/mol) of -11.50, -10.67, -10.37, -9.76 and -9.72, respectively, with inhibition constants ranging between 0.01 and 0.08 µM. The CYP3A4 depicted minimum binding energy (-9.51 kcal/mol) which is in agreement with the wet-lab reports. Further, relatively better affinity of CYP1A1 and CYP1B1 with the dibenzo[a,l]pyrene-11,12-diol (DBPD) might be indicative of their involvement in carcinogenicity of parent compound. Like DBP, BP (-10.13 kcal/mol, Ki: 0.04 µM) and BP-diols (BPD) (-9.01 kcal/mol, Ki: 0.25 µM) observed plausible binding with CYP1A1 supporting to the reported data that emphasize the major contribution of CYP1A1 in the activation of similar procarcinogens and mutagens. Likewise, in silico results further highlighted the CYP1A1 as key player in bioactivation of DMBA to its carcinogenic metabolites. In case of PhIP metabolism, strong binding interaction predicted with CYP1A1 (-9.63 kcal/mol) rather than CYP1A2 (-8.84 kcal/mol). Dissimilarity in the binding affinity of PhIP might be due to its basic scaffold. Further, molecular dynamics (MD) simulation of 10 ns has been revealed that docked complexes of CYP1A1 with DBP, DMBA and BP are comparatively more stable than the complex of PhIP. Moreover, the current findings might be valuable as reference model in prediction and elucidation of the approximate metabolic pathway of xenobiotics.

Molecular docking analysis of aplysin analogs targeting survivin protein.

Survivin (IAP proteins) remains an important target for anticancer drug development as it is reported to be over-expressed in tumor cells to enhance resistance to apoptotic stimuli. The study focuses on virtual screening of marine compounds inhibiting survivin, a multifunctional protein, using a computational approach. Structures of compounds were prepared using ChemDraw Ultra 10. Software and converted into its 3D PDB structure and its energy was minimized using Discovery Studio client 2.5. The target protein, survivin was retrieved from RCSB PDB. Lipinski's rule and ADMET toxicity profiling was carried out on marine compounds and the filtered compounds were further promoted for molecular docking analysis and interaction studies using AutoDock Tools 4.0. Molecular docking results revealed that analog (AP 4) of Aplysin, showed very promising inhibitory potential against survivin with a binding energy of -8.75 kcal/mol and Ki 388.28 nM as compared to its known inhibitor, Celecoxib having binding energy of -6.65 kcal/mol and Ki 13.43 µM. AP 4. The analog depicted similarity in pattern when compared to standard. The result proposes AP 4, is an effective molecule exhibiting prominent potential to inhibit survivin and thus promoting apoptosis in tumor cells.

In silico CD4+, CD8+ T-cell and B-cell immunity associated immunogenic epitope prediction and HLA distribution analysis of Zika virus.

Zika virus (ZIKV) is a mosquito-borne flavivirus distributed all over Africa, South America and Asia. The infection with the virus may cause acute febrile sickness that clinically resembles dengue fever, yet there is no vaccine, no satisfactory treatment, and no means of evaluating the risk of the disease or prognosis in the infected people. In the present study, the efficacy of the host's immune response in reducing the risk of infectious diseases was taken into account to carry out immuno-informatics driven epitope screening strategy of vaccine candidates against ZIKV. In this study, HLA distribution analysis was done to ensure the coverage of the vast majority of the population. Systematic screening of effective dominant immunogens was done with the help of Immune Epitope & ABCPred databases. The outcomes suggested that the predicted epitopes may be protective immunogens with highly conserved sequences and bear potential to induce both protective neutralizing antibodies, T & B cell responses. A total of 25 CD4+ and 16 CD8+ peptides were screened for T-cell mediated immunity. The predicted epitope "TGLDFSDLYYLTMNNKHWLV" was selected as a highly immunogenic epitope for humoral immunity. These peptides were further screened as non-toxic, immunogenic and non-mutated residues of envelop viral protein. The predicted epitope could work as suitable candidate(s) for peptide based vaccine development. Further, experimental validation of these epitopes is warranted to ensure the potential of B- and T-cells stimulation for their efficient use as vaccine candidates, and as diagnostic agents against ZIKV.

Screening and Elucidation of Selected Natural Compounds for Anti- Alzheimer's Potential Targeting BACE-1 Enzyme: A Case Computational Study.

BACKGROUND: The present study clarifies the molecular interactions of human BACE1 with novel natural ligands and also with the well-known ligand 2, 2, 4-trihydroxychalcone and Galangin for comparison. OBJECTIVE: The study of enzyme- ligands interaction is interesting, thus description of ligands binding to the active site of target molecule could be beneficial for better understanding the mechanism of the ligand on the target molecule. METHODS: Lipinski rule of five and docking study were performed between ligands and enzyme using 'Autodock4.2'. RESULTS: It was found that hydrogen bond interactions play a significant role in the accurate positioning of ligands within the 'active site' of BACE1 to permit docking. Such information may aid to propose the BACE1 -inhibitors and is estimated to aid in the safe medical use of ligands. Selected ligands of BACE1 also inhibit the aggregated amyloid beta peptide. The aggregation of amyloid peptides Aß1-42 may be responsible for AD. CONCLUSION: Scope lies in the determination of the 3-dimensional structure of BACE1 and ligands complex by X-ray crystallography to certify the explained data. To validate the enzyme -ligands results, we considered 2, 2, 4-trihydroxychalconeas and Galangin as a positive control. Moreover, the current study verifies that ligands are more capable inhibitors of human BACE1 compared to positive control with reference to ΔG values.

Identification of potential leads against 4-hydroxytetrahydrodipicolinate synthase from Mycobacterium tuberculosis.

4-hydroxy-tetrahydrodipicolinate synthase (DHDPS) is an important enzyme needed for the biosynthesis of lysine and many more key metabolites in Mycobacterium tuberculosis (Mtb). Inhibition of DHDPS is supposed to a promising therapeutic target due to its specific role in sporulation, cross-linking of the peptidiglycan polymers and biosynthesis of amino acids. In this work, a known inhibitor-based similarity search was carried out against a natural products database (Super Natural II) towards identification of more potent phyto-inhibitors. Molecular interaction studies were accomplished using three different tools to understand and establish the participation of active site residues as the key players in stabilizing the binding mode of ligands and target protein. The best phyto-compound deduced on the basis of binding affinity was further used as a template to make similarity scan across the PubChem Compound database (score > = 80 %) to get more divesred leads. In this search 5098 hits were obtained that further reduced to 262 after drug-likeness filtration. These phytochemicallike compounds were docked at the active site of DHDPS.Then, those hits selected from docking analysis that showing stronger binding and forming maximum H-bonds with the active site residues (Thr54, Thr55, Tyr143, Arg148 and Lys171). Finally, we predicted one phytochemical compound (SN00003544), two PubChem-compounds (CID41032023, CID54025334) akin to phytochemical molecule showing better interactions in comaprison of known inhibitors of target protein.These findings might be further useful to gain the structural insight into the designing of novel leads against DapA family.

Exploitation of in silico potential in prediction, validation and elucidation of mechanism of anti-angiogenesis by novel compounds: comparative correlation between wet lab and in silico data.

This study describes in silico validation of the wet lab data from aeroplysinin-1, curcumin and halofuginone using Autodock Tools 4.0. The inhibition patterns of the vascular endothelial cell differentiation and capillary tube formation mediated by anti-angiogenic growth factors from these test compounds were found quite comparable with the in silico results using angiogenic targets (EFGR, bFGF and VEGFR-1). Successful validation of the wet lab results of the selected angiogenic targets by in silico method has led to exploit the hidden potential of in silico tools in preliminary screening of the unknown compounds for anti-angiogenic potential in a cost-effective manner.

Dietary phytochemicals as potent chemotherapeutic agents against breast cancer: Inhibition of NF-κB pathway via molecular interactions in rel homology domain of its precursor protein p105.

BACKGROUND: Dietary phytochemicals consist of a wide variety of biologically active compounds that are ubiquitous in plants, many of which have been reported to have anti-tumor as well as anti-inflammatory properties. OBJECTIVE: In the present study, we aimed to validate these findings by using docking protocols and explicate the possible mechanism of action for a dataset of nine phytochemicals namely boswellic acid, 1-caffeoylquinic acid, ellagic acid, emodin, genistein, guggulsterone, quercetin, resveratrol, and sylibinin from different plants against the nuclear factor- kappaB (NF-κB) precursor protein p105, an important transcription factor reported to be overexpressed in breast cancer. MATERIALS AND METHODS: 2-D structures of all phytochemicals were retrieved from PubChem Compound database and their subsequent conversion into 3-D structures was performed by using online software system CORINA. The X-ray crystallographic structure of the NF-κB precursor p105 was extracted from Brookhaven Protein Data Bank. Molecular docking simulation study was carried out by using AutoDock Tools 4.0. RESULTS: Our results showed significant binding affinity of different phytochemicals with the Rel homology domain of the NF-κB precursor protein p105. Quercetin and 1-caffeoylquinic acid were found to be very effective inhibitors against target molecule as they showed binding energy of -12.11 and -11.50 Kcal/mol, respectively. The order of affinity of other ligands with p105 was found as follows: guggulsterone > sylibinin > emodin > resveratrol > genistein > boswellic acid > ellagic acid. CONCLUSION: Our in silico study has explored the possible chemopreventive mechanism of these phytochemicals against the NF-κB precursor protein p105 and deciphered that quercetin, 1-caffeoylquinic acid and guggulsterone were the potent inhibitors against target molecule. In addition, large scale preclinical and clinical trials are needed to explore the role of these chemotherapeutic molecules against the NF-κB precursor protein p105 in cure and prevention of breast cancer.

Causative relationship between diabetes mellitus and breast cancer in various regions of Saudi Arabia: an overview.

The unwarranted connection between diabetes mellitus and breast cancer has gained new ground in recent years. Breast cancer in Saudi females accounts for approximately 21% of all cancers and the prevalence of diabetes mellitus (DM) in Saudi females is also 21.5%. DM is diagnosed in the age group of 30+ years with possible exposure to predisposing factors like hyperinsulinemia and obesity at younger age. Further, 12% of the breast cancer cases are diagnosed in the young females aged 20-34 years. Despite the readily available access to healthcare facilities in the Kingdom, a large number of diabetics, approximately 27.9%, were unaware of having diabetes mellitus. This subpopulation is quite susceptible of developing breast cancer at later age. This review discusses common etiological and predisposing factors for breast cancer and diabetes, regional distribution and possible correlation of diabetes and cancer in Saudi Arabia.

Protective effect of dietary tocotrienols against infection and inflammation-induced hyperlipidemia: an in vivo and in silico study.

Currently used hypolipidemic drugs, Fluvastatin and Atorvastatin, act via inhibiting the rate-limiting enzyme 3-hydroxy-3-methyl-glutaryl-coenzyme A (HMG-CoA) reductase of the mevalonate pathway. The associated severe side-effects of these statins led us to explore the therapeutic potentials of naturally occurring Tocomin (mixture of dietary α-, ß-, γ- and δ-tocotrienols). Tocomin (10 mg) was orally administered daily for 10 days before and 12 h after bacterial lipopolysaccharide (200 µg) or 24 h after zymosan (20 mg) or turpentine (0.5 mL) to Syrian hamsters. The data showed that Tocomin significantly reduced the levels of plasma and lipoprotein lipids, cholesterol, apoB, small dense (sd)-LDL as well as LDL in the hyperlipidemia-induced hamsters. Further, the mechanism of action of α-, ß-, γ- and δ-tocotrienols was validated by docking studies with HMG-CoA reductase enzyme using the Molegro Virtual Docker. The inhibition of HMG-CoA reductase predicted in terms of MolDockScore and interaction energy suggest the comparative potential in the descending order: Atorvastatin > Fluvastatin ~ δ > γ > ß > α. The results favor the daily intake of naturally occurring tocotrienols as dietary supplement in the prevention and treatment of infection/inflammation induced dyslipidemia compared with the hypolipidemic drugs.

Antimicrobial, antioxidant, and antimutagenic activities of selected marine natural products and tobacco cembranoids.

Multidrug resistance (MDR) in microorganisms is a cause of major concern for clinicians and pharmaceutical industries. Continuous development of new antimicrobial drugs with multiple targets and potentials is expected to efficiently combat MDR in these microorganisms. In a continued exploration of new antimicrobial drug leads, 11 marine natural products, semisynthetic, or related synthetic analogs (1-11) and two tobacco cembranoids (12 and 13) were screened for their antimicrobial, antioxidant, and antimutagenic activities. Eight compounds showed varying levels of both antibacterial and antifungal activities. Compounds such as 17-O-methyllatrunculin-A, verongiaquinol, (1S,2E,4R,6R,7E,11E)-2,7,11-cembratriene-4,6-diol), and manzamine-A showed a broad spectrum of activity, inhibiting six of seven tested bacteria with zone of inhibition diameter from 9 to 30 mm. Four of these active compounds also showed antifungal activity. The findings of the in vitro time-kill assay of the most active compound, verongiaquinol, against Staphylococcus aureus indicated its subinhibitory effect at the level lower than the minimal inhibitory concentration (MIC) values (i.e., 2 and 4 µg/mL). At the MIC (8 µg/mL), bacterial cells were completely killed within 18 hours of incubation. DPPH free radical scavenging activity was demonstrated by five compounds in the range of 89.65-36.19% decolorization. Further, four compounds evaluated for their antimutagenic activity against the directly acting mutagens, methyl methanesulfonate and sodium azide, in Salmonella typhimurium strains, interestingly, showed no sign of mutagenicity. Verongiaquinol and manzamine A, in fact, reduced the mutagenicity by 50-75% at a dose of 5 µg/plate in different test strains. Our study seems to provide some novel antimicrobial leads with strong antioxidant potential and the associated ability of antimutagenicity.

Genotoxic fungicide methyl thiophanate as an oxidative stressor inducing 8-oxo-7,8-dihydro-2' -deoxyguanosine adducts in DNA and mutagenesis.

Dimethyl 4,4' -(O-phenylene)bis(3-thioallophanate), commonly known as methyl thiophanate (MT), is a systemic fungicide and suspected carcinogen to humans. In this study, the oxidative potential of this category-III acute toxicant has been ascertained based on its capacity of inducing reactive oxygen species (ROS) and promutagenic 8-oxo-7,8-dihydro-2' -deoxyguanosine (8-oxodG) adducts in DNA. The discernible MT dose-dependent reduction in fluorescence intensity of a cationic dye rhodamine (Rh-123) in human lymphocytes and increased fluorescence intensity of 2',7'-Dichlorodihydro fluorescein diacetate (DCFH-DA) treated cells signifies decreased mitochondrial membrane potential (Delta Psi m) due to intracellular ROS generation. The (32)P-post-labeling assay demonstrated the MT-induced 8-oxodG adduct formation in calf thymus DNA. Thus, it is concluded that MT, as a potent oxidative stressor, produces ROS leading to mitochondrial dysfunction, oxidative DNA damage and mutagenesis.

Evaluation of cytotoxic potential of newly synthesized antiviral aminopyrazoloquinoline derivatives.

In the present study, we screened newly synthesized antiviral aminopyrazoloquinoline derivatives for cytotoxic potential in human normal and breast cancer cell lines using apoptosis as biomarker. These derivatives and the well known antiviral drug, acyclovir, were incubated with the normal (MCF-10A, MCF-12A) and cancer (MCF-7, MDA-MB-231) cell lines at 10, 50 and 100 µM for 72 h at 37°C. Both the parent compounds and their sugar derivatives were found to be differentially cytotoxic in various cell lines. MCF-7 cells were more or less completely resistant to all these compounds while MDA-MB-231 cells were significantly killed by apoptosis. The methoxy derivative of aminopyrazoloquinoline (compound 3) was found to be the most cytotoxic in the normal breast epithelial cell lines (MCF-10A and MCF-12A) and MDA-MB-231 cell lines at 100 µM killing over 90% of the cells with up to 80% apoptosis. Interestingly MCF-7 cells showed only up to 50% killing at 100 µM dose with less than 20% apoptosis. Acyclovir did not cause any cytotoxicity, apoptosis or cell cycle arrest in any of the cells lines at the doses tested. Our results suggest that the newly synthesized antiviral compounds have an associated risk of being cytotoxic compared to the acyclovir.