Anticancer Phytochemical-Based Nanoformulations: Therapeutic Intervention in Cancer Cell Lines.

Phytochemicals have the potential to treat resistant cancer. They are delivered to the target site via nano-based carriers. Promising results are seen in preclinical and in vitro models, as phytochemical-based nanoformulations have improved cell cytotoxicity compared to single agents. They can synergistically inhibit cancer cell growth through p53 apoptosis in MCF-7 breast cancer cell lines. Moreover, synergic viability in reproducible glioma models at half inhibitory concentrations has been shown. Through caspase activation, phytochemical-based nanoformulations also increase cell death in 4T1 breast cancer cell lines. They have shown improved cytotoxicity at half inhibitory concentrations compared to single-agent drugs in cervical cancer. In terms of colorectal cancer, they have the potential to arrest cells in the S phase of the cell cycle and synergistically inhibit cell proliferation. In squamous cell carcinoma of the tongue, they inhibit protein kinase B (Akt)/mammalian target of rapamycin (mTOR) pathways. This review reports on developments in the therapeutic management of various cancers using phytochemical-based nanoformulations, which have shown potential benefits in the clinical management of cancer patients, halting/slowing the progression of the disease and ameliorating chemotherapy-induced toxicities.

Promises of phytochemical based nano drug delivery systems in the management of cancer.

Cancer is the leading cause of human disease and death worldwide, accounting for 7.6 million deaths per year and projected to reach 13.1 million by 2030. Many phytochemicals included in traditional medicine have been utilized in the management of cancer. Conventional chemotherapy is generally known to be the most effective treatment of metastatic cancer but these cancerous cells might grow resistant to numerous anticancer drugs over time that resulting in treatment failure. This review tried to portray the advancement in the anticancer and chemopreventive effects of several phytochemicals and some of its members encapsulated in the nano-based delivery system of the drug. It comprises the issue associated with limited use of each phytoconstituents in human cancer treatment are discussed, and the benefits of entrapment into nanocarriers are evaluated in terms of drug loading efficiency, nanocarrier size, release profile of the drug, and in vitro and/or in vivo research and treatment testing, such as cytotoxicity assays and cell inhibition/viability.

Identification of 3-((1-(Benzyl(2-hydroxy-2-phenylethyl)amino)-1-oxo-3-phenylpropan-2-yl)carbamoyl)pyrazine-2-carboxylic Acid as a Potential Inhibitor of Non-Nucleosidase Reverse Transcriptase Inhibitors through InSilico Ligand- and Structure-Based Approaches.

Non-nucleosidase reverse transcriptase inhibitors (NNRTIs) are highly promising agents for use in highly effective antiretroviral therapy. We implemented a rational approach for the identification of promising NNRTIs based on the validated ligand- and structure-based approaches. In view of our state-of-the-art techniques in drug design and discovery utilizing multiple modeling approaches, we report here, for the first time, quantitative pharmacophore modeling (HypoGen), docking, and in-house database screening approaches in the identification of potential NNRTIs. The validated pharmacophore model with three hydrophobic groups, one aromatic ring group, and a hydrogen-bond acceptor explains the interactions at the active site by the inhibitors. The model was implemented in pharmacophore-based virtual screening (in-house and commercially available databases) and molecular docking for prioritizing the potential compounds as NNRTI. The identified leads are in good corroboration with binding affinities and interactions as compared to standard ligands. The model can be utilized for designing and identifying the potential leads in the area of NNRTIs.

Coelogin ameliorates metabolic dyshomeostasis by regulating adipogenesis and enhancing energy expenditure in adipose tissue.

Obesity and associated metabolic disorders are heading up with an alarming rate in developing nations. One of highly sought solution for metabolic disorders is to identify natural molecule with an ability to reduce obesity and increase insulin sensitivity. Coelogin (CLN) is a phenanthrene derivative isolated from the ethanolic extract of Coelogyne cristata. In our constant efforts to identify novel anti-dyslipidemic and anti-adipogenic compounds using CFPMA (common feature pharmacophore model using known anti-adipogenic compounds) model, predicted possible anti-adipogenic activity of CLN. In vitro results showed significant inhibition of adipogenesis in 3T3-L1 and C3H10T1/2 cell by CLN. It arrests the cell cycle in G1 phase of interphase and inhibits mitotic clonal expansion to regulate adipogenesis. CLN elicits insulin sensitizing effect in mature adipocytes. During extracellular flux assessment studies, it increases oxidative respiration and energy expenditure in adipocytes. In vivo, CLN reversed HFD-induced dyslipidemia as well as insulin resistance in C57BL/6 mice. It promoted the expression of genes involved in improved mitochondrial function and fatty acid oxidation in eWAT. CLN restored energy expenditure and increased the capacity of energy utilization in HFD fed mice. Taken together, the study indicated beneficial effects of CLN in combating obesity-associated metabolic complications.

Pharmacophore modeling, docking and the integrated use of a ligand- and structure-based virtual screening approach for novel DNA gyrase inhibitors: synthetic and biological evaluation studies.

Fluoroquinolones, a class of compound, act via inhibiting DNA gyrase and topoisomerase IV enzymes. This is an important class of drugs with high success rates for the treatment of tuberculosis and other bacterial infections. An indirect drug design approach was used to develop a meaningful pharmacophore model using the HypoGen module of Discovery Studio 2.0 on a set of 27 structurally diverse compounds with a wide range of biological activity (5 log units). The best hypothesis had three hydrogen bond acceptors (HBA) and one hydrophobic (Hy) moiety, showing r = 0.95, and it predicts the test set of 44 compounds well, with r 2 = 0.823. The same features (acceptor and hydrophobic functionality) were validated at the binding site of the DNA gyrase active site using GOLD version 3.0.1 and Molegro Virtual Docker, which showed corresponding hydrogen bond interactions and also π-π stacking interactions that correlated well with the PIC50 values (r 2 = 0.6142). The thoroughly validated model was used to screen an extensive database of 0.25 million compounds to identify potential leads. The validated model was implemented for the identification, design, synthesis, and biological evaluation of leads. Ten new chemical entities were synthesized based on our scaffold hopping techniques from the identified virtual screening and tested against the tuberculosis bacterium to obtain preliminary MIC values. The results showed that 3 out of 10 synthesized compounds exhibited good MICs, from 1.25 to 50 µM. This proves the robustness and applicability of the developed model, which is a promising tool for identifying new topoisomerase II inhibitors for the treatment of tuberculosis.

Pharmacophore-based approaches in the rational repurposing technique for FDA approved drugs targeting SARS-CoV-2 Mpro.

Novel coronavirus (CoV) is the primary etiological virus responsible for the pandemic that started in Wuhan in 2019-2020. This viral disease is extremely prevalent and has spread around the world. Preventive steps are restricted social contact and isolation of the sick individual to avoid person-to-person transmission. There is currently no cure available for the disease and the search for novel medications or successful therapeutics is intensive, time-consuming, and laborious. An effective approach in managing this pandemic is to develop therapeutically active drugs by repurposing or repositioning existing drugs or active molecules. In this work, we developed a feature-based pharmacophore model using reported compounds that inhibit SARS-CoV-2. This model was validated and used to screen the library of 565 FDA-approved drugs against the viral main protease (Mpro), resulting in 66 drugs interacting with Mpro with higher binding scores in docking experiments than drugs previously reported for the target diseases. The study identified drugs from many important classes, viz. D2 receptor antagonist, HMG-CoA inhibitors, HIV reverse transcriptase and protease inhibitors, anticancer agents and folate inhibitors, which can potentially interact with and inhibit the SARS-CoV-2 Mpro. This validated approach may help in finding the urgently needed drugs for the SARS-CoV-2 pandemic with infinitesimal chances of failure.

Correction: Pharmacophore-based approaches in the rational repurposing technique for FDA approved drugs targeting SARS-CoV-2 Mpro.

[This corrects the article DOI: 10.1039/D0RA06038K.].

Targeting Caspase 8: Using Structural and Ligand-Based Approaches to Identify Potential Leads for the Treatment of Multi-Neurodegenerative Diseases.

Caspase 8 is a central player in the apoptotic cell death pathway and is also essential for cytokine processing. The critical role of this protease in cell death pathways has generated research interest because its activation has also been linked with neural cell death. Thus, blocking the activity of caspase 8 is considered a potential therapy for neurodegenerative diseases. To extend the repertoire of caspase 8 inhibitors, we employed several computational approaches to identify potential caspase 8 inhibitors. Based on the structural information of reported inhibitors, we designed several individual and consensus pharmacophore models and then screened the ZINC database, which contains 105,480 compounds. Screening generated 5332 candidates, but after applying stringent criteria only two candidate compounds, ZINC19370490 and ZINC04534268, were evaluated by molecular dynamics simulations and subjected to Molecular Mechanics/Poisson Boltzmann Surface Area (MM-PBSA) analysis. These compounds were stable throughout simulations and interacted with targeted protein by forming hydrogen and van der Waal bonds. MM-PBSA analysis showed that these compounds were comparable or better than reported caspase 8 inhibitors. Furthermore, their physical properties were found to be acceptable, and they are non-toxic according to the ADMET online server. We suggest that the inhibitory efficacies of ZINC19370490 and ZINC04534268 be subjected to experimental validation.

Aegeline inspired synthesis of novel ß3-AR agonist improves insulin sensitivity in vitro and in vivo models of insulin resistance.

BACKGROUND AND PURPOSE: In our drug discovery program of natural product, earlier we have reported Aegeline that is N-acylated-1-amino-2- alcohol, which was isolated from the leaves of Aeglemarmelos showed anti-hyperlipidemic activity for which the QSAR studies predicted the compound to be the ß3-AR agonist, but the mechanism of its action was not elucidated. In our present study, we have evaluated the ß3-AR activity of novel N-acyl-1-amino-3-arylopropanol synthetic mimics of aegeline and its beneficial effect in insulin resistance. In this study, we have proposed the novel pharmacophore model using reported molecules for antihyperlipidemic activity. The reported pharmacophore features were also compared with the newly developed pharmacophore model for the observed biological activity. EXPERIMENTAL APPROACH: Based on 3D pharmacophore modeling of known ß3AR agonist, we screened 20 synthetic derivatives of Aegeline from the literature. From these, the top scoring compound 10C was used for further studies. The in-slico result was further validated in HEK293T cells co-trransfected with human ß3-AR and CRE-Luciferase reporter plasmid for ß3-AR activity.The most active compound was selected and ß3-AR activity was further validated in white and brown adipocytes differentiated from human mesenchymal stem cells (hMSCs). Insulin resistance model developed in hMSC derived adipocytes was used to study the insulin sensitizing property. 8 week HFD fed C57BL6 mice was given 50 mg/Kg of the selected compound and metabolic phenotyping was done to evaluate its anti-diabetic effect. RESULTS: As predicted by in-silico 3D pharmacophore modeling, the compound 10C was found to be the most active and specific ß3-AR agonist with EC50 value of 447 nM. The compound 10C activated ß3AR pathway, induced lipolysis, fatty acid oxidation and increased oxygen consumption rate (OCR) in human adipocytes. Compound 10C induced expression of brown adipocytes specific markers and reverted chronic insulin induced insulin resistance in white adipocytes. The compound 10C also improved insulin sensitivity and glucose tolerance in 8 week HFD fed C57BL6 mice. CONCLUSION: This study enlightens the use of in vitro insulin resistance model close to human physiology to elucidates the insulin sensitizing activity of the compound 10C and edifies the use of ß3AR agonist as therapeutic interventions for insulin resistance and type 2 diabetes.

Aegeline inspired synthesis of novel amino alcohol and thiazolidinedione hybrids with antiadipogenic activity in 3T3-L1 cells.

Excess adiposity is a hallmark of obesity, which is caused due to an imbalance between energy intake and energy consumed. Obesity is often associated with several metabolic disorders like dyslipidemia, cardiovascular diseases and type 2 diabetes. Earlier, our group had reported natural product Aegeline (amino-alcohol) isolated from the plant Aegle marmelos as an anti-diabetic and anti-dyslipidemic compound. With this background, we synthesized a series of novel amino alcohol and thiazolidinedione hybrid molecules and studied their antiadipogenic activity. As a result, we have identified a potent hybrid compound 12c as an inhibitor of adipocyte differentiation. The compound 12c inhibits lipid accumulation and adipogenesis in 3T3-L1 preadipocyte cell line. Exposure of compound 12c blocks mitotic clonal expansion and arrests cells in S-phase of cell cycle. Detailed analysis showed that compound 12c decreases expression of two major transcription factors that are involved in adipocyte differentiation, PPARγ, C/EBPα, and other adipogenesis associated genes like aP2 and FAS. Thus, we concluded that compound 12c shows potential ability to inhibit adipocyte differentiation which can be used therapeutically for the treatment of obesity and its associated metabolic disorders.

Curcumin-3,4-Dichloro Phenyl Pyrazole (CDPP) overcomes curcumin's low bioavailability, inhibits adipogenesis and ameliorates dyslipidemia by activating reverse cholesterol transport.

BACKGROUND: Adipocyte dysfunction, obesity and associated metabolic disorders are of prime healthcare concern worldwide. Among available medications, natural products and inspired molecules hold 40% space in clinically prescribed medicines. In queue, this study overcomes the drawback of curcumin's low bioavailability with potent anti-adipogenic and anti-dyslipidemic activity. METHODS: To evaluate the role of CDPP on adipocyte differentiation, 3T3-L1 adipocytes were used as an in-vitro model. Flow cytometry was performed for cell cycle analysis. Syrian golden hamsters were used to study pharmacokinetic profile and dyslipidemic activity exhibited by CDPP. RESULT: CDPP was found to be a potent inhibitor of adipogenesis in-vitro. It blocked mitotic clonal expansion by causing cell cycle arrest. CDPP showed marked improvement in gastrointestinal stability and bioavailability in-vivo as compared to curcumin. Administration of CDPP (100mg/kg) significantly improved HFD induced dyslipidemic profile in hamsters and activated reverse cholesterol transport machinery. CONCLUSION: CDPP could be used as a potential drug candidate against adipogenesis and dyslipidemia with enhanced gastrointestinal stability and bioavailability.

Design, synthesis and evaluation of benzofuran-acetamide scaffold as potential anticonvulsant agent.

A series of N-(2-(benzoyl/4-chlorobenzoyl)-benzofuran- 3-yl)-2-(substituted)-acetamide derivatives (4a-l, 5a-l) was synthesized in good yield. All synthesized compounds were in agreement with elemental and spectral data. The anticonvulsant activity of all synthesized compounds was assessed against the maximal electroshock induced seizures (MES) model in mice. Neurotoxicity was evaluated using the rotarod method. The majority of compounds exhibited anticonvulsant activity at a dose of 30 mg kg-1 body mass during 0.5-4 h, indicating their ability to prevent seizure spread at low doses. Relative to phenytoin, [N-(2-(4-chlorobenzoyl)benzofuran-3-yl)-2-(cyclohexyl( methyl) amino)-acetamide] (5i) and [N-(2-(4-chlorobenzoyl)benzofuran-3-yl)-2-(4-methylpiperidin-1- yl)-acetamide] (5c) demonstrated comparable relative anticonvulsant potency of 0.74 and 0.72, respectively, whereas [(N-(2-(4-chlorobenzoyl)benzofuran-3-yl)-2-(4-(furan-2-carbonyl)-piperazin-1-yl)-acetamide] (5f) exhibited the lowest relative potency of 0.16. The ALD50 of tested compounds ranged from 1.604 to 1.675 mmol kg-1 body mass. The ED50 of synthesized compounds ranged from 0.055 to 0.259 mmol kg-1 (~23.4 to 127.6 mg kg-1) body mass. The pharmacophore mapping of the examined compounds on standard drugs (phenobarbital, phenytoin, ralitolin and carbamazepine) strongly suggests that these compounds may exert their anticonvulsant activity via the same established mechanism as that of known drugs.

Designing, synthesis of selective and high-affinity chalcone-benzothiazole hybrids as Brugia malayi thymidylate kinase inhibitors: In vitro validation and docking studies.

In our continuing search for safe and efficacious antifilarials, a series of novel chalcone-benzothiazole hybrids have been synthesized and evaluated for their Brugia malayi thymidylate kinase (BmTMK) enzyme inhibition activity. Their selectivity towards BmTMK was studied and compared to the human TMK (HsTMK) by an in silico method. Out of seventeen derivatives, compounds 34 and 42 showed higher interactions with the BmTMK active site. MolDock docking model revealed the interactions of these two derivatives and the results corroborated well with their in vitro antifilarial activities. Our studies suggest that these hybrids are selective towards the BmTMK enzyme and may serve as potential therapeutic agents against filariasis.

Homology modeling and virtual screening of inhibitors against TEM- and SHV-type-resistant mutants: A multilayer filtering approach.

TEM and SHV are class-A-type ß-lactamases commonly found in Escherichia coli and Klebsiella pneumoniae. Previous studies reported S130G and K234R mutations in SHVs to be 41- and 10-fold more resistant toward clavulanic acid than SHV-1, respectively, whereas TEM S130G and R244S also showed the same level of resistance. These selected mutants confer higher level of resistance against clavulanic acid. They also show little susceptibility against other commercially available ß-lactamase inhibitors. In this study, we have used docking-based virtual screening approach in order to screen potential inhibitors against some of the major resistant mutants of SHV and TEM types ß-lactamase. Two different inhibitor-resistant mutants from SHV and TEM were selected. Moreover, we have retained the active site water molecules within each enzyme. Active site water molecules were placed within modeled structure of the mutant whose structure was unavailable with protein databank. The novelty of this work lies in the use of multilayer virtual screening approach for the prediction of best and accurate results. We are reporting five inhibitors on the basis of their efficacy against all the selected resistant mutants. These inhibitors were selected on the basis of their binding efficacies and pharmacophore features.

Identification of novel PTP1B inhibitors by pharmacophore based virtual screening, scaffold hopping and docking.

Design and synthesis of protein tyrosine phosphatases-1B (PTP1B) inhibitors are important for the drugs targeted to treat diabetes and obesity. The pharmacophore modeling, docking and scaffold hopping techniques have been applied to discover the novel PTP1B inhibitors. The ten prioritized compounds (115-119, 120-121, 127, 130-131) from the library of 86 compounds were synthesized and found positive in the micro molar range for PTP1B in-vitro inhibitory assays as compared to Suramin (IC50 9.5 µM). Among these five active compounds (115-119) were tested in STZ-s induced diabetic rat model and the most active compound 115 in this test, was further tested in C57BL/KsJ-db/db mice where it significantly improved OGTT along with the fasting and random blood glucose level. The treatment by the compound 115 significantly improved the insulin resistance and insulin signaling by restoring the insulin level and normalizing the serum lipid profile. Compound 115 also augmented the insulin action by modulating the expression of genes involved in insulin signaling like IRS 1-2, PI3K, PTPN1, Akt2, AMPK and PPAR-α. Western blot analysis of both skeletal muscle and liver demonstrated that proteins and intermediate enzymes of insulin signaling were also increased as compared to control group. The compound 115 was also investigated for anti-adipogenic effect on 3T3L-1 cells. The compound 115 inhibited MDI induced lipid accumulation in a dose-dependent manner. The oral bioavailability of compound 115 was ∼10.29% after 30 mg/kg oral dosing assessed in rat.

Identification of potent caspase-3 inhibitors for treatment of multi- neurodegenerative diseases using pharmacophore modeling and docking approaches.

Neurodegenerative disorders are due to excessive neuronal apoptosis and the caspase-3 plays a key role in the apoptotic pathway. The caspase-3 inhibition may be a validated therapeutic approach for neurodegenerative disorders and an interesting target for molecular modeling studies using both Ligand and structure based approaches. In view of the above we have generated the Ligand based pharmacophore model using the Discovery studio 2.0 software. In addition to this a structure based approach has been used to validate the developed pharmacophoric features to gain a deeper insight into its molecular recognition process. This validated pharmacophore and the docking model was then implemented as a query for pharmacophore based virtual screening to prioritize the probable hits for the Caspase-3. Two ligands, ZINC12405015 and ZINC12405043 were finally selected on the basis of their fit values and docking scores. This study also reveals the important amino acids viz. His-121, Ser-205, Arg-207 which were found to be playing crucial role in the binding of the selected compounds within the active site of caspase-3.

Identification of novel phenyl butenonyl C-glycosides with ureidyl and sulfonamidyl moieties as antimalarial agents.

A new series of C-linked phenyl butenonyl glycosides bearing ureidyl(thioureidyl) and sulfonamidyl moieties in the phenyl rings were designed, synthesized, and evaluated for their in vitro antimalarial activities against Plasmodium falciparum 3D7 (CQ sensitive) and K1 (CQ resistant) strains. Among all the compounds screened the C-linked phenyl butenonyl glycosides bearing sulfonamidyl moiety (5a) and ureidyl moiety in the phenyl ring (7d and 8c) showed promising antimalarial activities against both 3D7 and K1 strains with IC50 values in micromolar range and low cytotoxicity offering new HITS for further exploration.

Pharmacokinetic and metabolism studies of rohitukine in rats by high performance liquid-chromatography with tandem mass spectrometry.

A sensitive, selective, and rapid high performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) was developed for the quantification of rohitukine in rat plasma. HPLC was performed using a Symmetry-Shield C18 (5 µ, 4.6 × 150 mm) column, and isocratic elution with ammonium acetate buffer (pH4; 10 mM):methanol (08:92, v/v) at a flow rate of 0.6 mL/min. Sample clean-up involved solid phase extraction (SPE) of analyte and internal standard (phenacetin) from 100 µL plasma. The parent→product ion transitions (MRM) for analyte and IS were 306.1→245.1 m/z and 180.1→138.1 m/z respectively, and were monitored on a triple quadrupole mass spectrometer, operating in positive ion mode. The method was validated across the dynamic concentration range of 5-500 ng/mL for rohitukine, with a fast run time of 4.5 min. The analytical method measured concentrations of rohitukine with accuracy (% bias) of <±10% and precision (% RSD) of <±12%. Rohitukine was stable during the battery of stability studies viz., bench-top, auto-sampler, freeze/thaw cycles and 30 days of storage in a freezer at -70±10°C. Finally, the applicability of this assay has been successfully demonstrated in vivo pharmacokinetic and in vitro metabolism studies in Sprague-Dawley rat. This method will therefore be highly useful for future preclinical and clinical pharmacokinetic studies of rohitukine.

Rohitukine inhibits in vitro adipogenesis arresting mitotic clonal expansion and improves dyslipidemia in vivo.

We developed a common feature pharmacophore model using known antiadipogenic compounds (CFPMA). We identified rohitukine, a reported chromone anticancer alkaloid as a potential hit through in silico mapping of the in-house natural product library on CFPMA. Studies were designed to assess the antiadipogenic potential of rohitukine. Rohitukine was isolated from Dysoxylum binacteriferum Hook. to ⬧95% purity. As predicted by CFPMA, rohitukine was indeed found to be an antiadipogenic molecule. Rohitukine inhibited lipid accumulation and adipogenic differentiation in a concentration- and exposure-time-dependent manner in 3T3-L1 and C3H10T1/2 cells. Rohitukine downregulated expression of PPARγ, CCAAT/enhancer binding protein α, adipocyte protein 2 (aP2), FAS, and glucose transporter 4. It also suppressed mRNA expression of LPL, sterol-regulatory element binding protein (SREBP) 1c, FAS, and aP2, the downstream targets of PPARγ. Rohitukine arrests cells in S phase during mitotic clonal expansion. Rohitukine was bioavailable, and 25.7% of orally administered compound reached systemic circulation. We evaluated the effect of rohitukine on dyslipidemia induced by high-fat diet in the hamster model. Rohitukine increased hepatic expression of liver X receptor α and decreased expression of SREBP-2 and associated targets. Rohitukine decreased hepatic and gonadal lipid accumulation and ameliorated dyslipidemia significantly. In summary, our strategy to identify a novel antiadipogenic molecule using CFPMA successfully resulted in identification of rohitukine, which confirmed antiadipogenic activity and also exhibited in vivo antidyslipidemic activity.

Molecular cloning and characterization of Brugia malayi thymidylate kinase.

Thymidylate kinase (TMK) is a potential chemotherapeutic target because it is directly involved in the synthesis of deoxythymidine triphosphate, which is an essential component for DNA synthesis. The gene encoding thymidylate kinase of Brugia malayi was amplified by PCR and expressed in Escherichia coli. The native molecular weight of recombinant B. malayi thymidylate kinase (rBmTMK) was estimated to be ∼52kDa by gel filtration chromatography, suggesting a homodimeric structure. rBmTMK activity required divalent cation and Mg(2+) was found to be the most effective cation. The enzyme was sensitive to pH and temperature, it showed maximum activity at pH 7.4 and 37°C. The Km values for dTMP and ATP were 17 and 66µM, respectively. The turnover number kcat was found to be 38.09s(-1), a value indicating the higher catalytic efficiency of the filarial enzyme. The nucleoside analogues 5-bromo-2'-deoxyuridine (5-BrdU), 5-chloro-2'-deoxyuridine (5-CldU) and 3'-azido-3'-deoxythymidine (AZT) showed specific inhibitory effect on the enzyme activity and these effects were in good association with binding interactions and the scoring functions as compared to human TMK. Differences in kinetic properties and structural differences in the substrate binding site of BmTMK model with respect to human TMK can serve as basis for designing specific inhibitors against parasitic enzyme.