Department Of Pharmaceutical Sciences and Natural Products
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Item Synthesis and Biological Evaluation of Inhibitors of Topoisomerases and Histone Deacetylase for In Vitro Anticancer Activity(Central University of Punjab, 2019) Joshi, Gaurav; Kumar, Raj & Singh, SandeepTopoisomerases (Topos) and histone deacetylases (HDACs) are validated oncotherapeutic targets due to their involvement in most of the cellular events such as initiation, proliferation, and survival of cancer cells. Widespread research has undergone to design and discover small molecule inhibitors of each protein which has led to the development of several drugs that are making their presence felt in clinic. Considering the issues of stability, toxicity, reported crosstalk(s) and resitance of existing pharmacophores, we herein report the discovery of target-based molecules pertaining to pyrazolo[1,5-c]quinazolines, 2-aryl quinolines and imidazo[1,2- a]quinoxaline scaffolds as inhibitors of TopoI or dual TopoI and II designed rationally via in silico tools. The chemical space of scaffolds was further exploited to design and synthesise dual/multi inhibitors of Topo-HDAC by connecting pharmacophoric features of HDAC inhibitors via a linker. Detailed biological evaluation of synthetics was performed using multiple cancer cell lines as well as normal cells/cell lines. Utilizing MTT, dye exclusion, redox potential, cell cycle and annexin V vs PI assays in 2D as well as 3D cultures, we established their preferential cytotoxic potential. Signaling responsible for anticancer mechanism was delineated using western immunoblotting and qPCR assays. Further, in vitro assays v for topoisomerases (DNA relaxation and catenation), and/or HDAC1 revealed target specificity of synthetics. In addition, we also demonstrated a novel bioreductive methodology, specific to cancer cells, exploiting cancer microenvironment leading to delivery of molecularly targeted agents as topo(s) inhibitors.Item Design, Synthesis and Evaluation of Donepezil-Rasagiline Based Compounds as Multipotent Inhibitors for the Treatment of Alzheimer’s Disease(Central University of Punjab, 2019) Kumar, Bhupinder; Kumar, VinodAlzheimer’s disease (AD) is multifactorial in nature and different enzymes including MAO, AChE, and amyloid beta are implicated in its pathogenesis. The pathomechanism of AD is complex in nature and single target drugs proved to be ineffective for the treatment of the disease. With an aim of developing dual/multipotent inhibitors, 4,6- diphenylpyrimidines were optionally substituted with propargyl group and an ethyl chain containing a cyclic or acyclic tertiary nitrogen atom (piperidine/morpholine/pyrrolidine/N,N-dimethyl) as potential pharmacophores for MAO and AChE enzymes. Compound VB1 was found to be the most potent MAO-A (IC50 value of 18.34 ± 0.38 nM) inhibitor and VB8 was found to be the most potent AChE (IC50 value of 9.54 ± 0.07 nM) inhibitor. Compound VB3 was another promising compound in series-I with IC50 values of 28.33 ± 3.22 nM and 18.92 ± 0.29 nM against MAO-A and AChE, respectively and displayed very high selectivity index (103) for AChE over BuChE. These compounds were found to be reversible inhibitors of MAO and AChE enzymes and non-toxic to the human neuroblastoma SH-SY5Y cells. Based on structure-activity relationship analysis of the first series of compounds, second series of the compounds were designed by fixing the position of piperidine/morpholine ethyl chain at the para position of one of the phenyl rings. In the second series, compound VP15 v was found to be a multi-potent inhibitor of MAO-B and AChE with IC50 values of 0.37 ± 0.03 μM and 0.04 ± 0.003 μM, respectively. VP15 was found to be selective for MAOB with selectivity index of 270 over MAO-A. It also displayed SI of 625 for AChE over BuChE. VP15 was found to be irreversible inhibitor of MAO-B. In the third series of target compounds, both the phenyl rings of diphenylpyrimidines were substituted with O-propargyl groups. Different derivatives have been synthesized with O-propargyl groups substituted at ortho, meta and para positions of the phenyl rings. In the third series of compounds, AVB1 and AVB4 were found to be the most potent inhibitors of AChE and MAO-B with IC50 values of 1.35 ±0.03 μM and 1.49 ± 0.09 μM, respectively. In the reversible inhibition studies, the lead compounds were found to be reversible inhibitors of MAO-B and AChE enzymes. In the ROS protection inhibition studies, AVB1 and AVB4 displayed good activity in SH-SY5Y cells and AVB1 reduced the ROS levels up to 30% at 5 μM. This series of compounds were also found to be non-toxic to the SH-SY5Y cells in the cytotoxicity studies. Thus, from the present study it can be concluded that 4,6-diphenylpyrimidine derivatives can act as potential lead for the development of effective drug candidates for the treatment of AD. Compound VB3 and VP15 were found to be the most potent dual inhibitors of MAO and AChE.Item Design, Synthesis and Evaluation of Indole Based Compounds as Putative Anticancer Agents(Central University of Punjab, 2018) Singla, Ramit; Jaitak, VikasIn the course of efforts to develop new chemotherapeutic agent for targeting breast cancer, indole-benzimidazole, indole-xanthendione, indole-chromene carbonitrile and indole-dihydropyridine derivatives were computationally designed and synthesized. All the compounds were first analyzed for antiproliferative activity using ER-α responsive T47D breast cancer cells line and cytotoxicity using hPBMC. Further, all the synthesized compounds were also evaluated for ER-α binding affinity. Lead compounds 5f and 8f of series 1 and 2; 10e and 10f of series 3, 11c and 12d of series 4 and 5 were found to be most active at both cellular and receptor level hence were biologically evaluated for gene expression studies for targeting ER-α. Cell imaging experiment clearly suggest that compounds were able to cross cell membrane and accumulate thus causing cytotoxicity. Semiquantitative RT-PCR and Western blotting experiments further supported that lead compounds altered the expression of mRNA and protein of ER-α, thereby preventing the further transactivation and signaling pathway in T47D cells line. Structural investigation from induced fit simulation study suggest that lead compounds binds in a conformation similar to bazedoxifene by extensive hydrogen bonding and Van der Waals forces. All these results indicate that compounds 5f, 8f, 10e, 10f, 11c and 12d represents new putative anticancer agents and can be proved promising in the discovery of antiestrogens for the management of breast cancer.Item SYNTHESIS AND ANTICANCER EVALUATION OF NOVEL HETEROCYCLICS DERIVED FROM IMIDAZOLE AND QUINOLINE SCAFFOLDS(Central University of Punjab, 2018) Chauhan, Monika; Kumar, RajItem Targeting cancer stem cells pathways for the effective treatment of cancer(Bentham Science Publishers, 2020) Dwivedi, A.R; Thakur, A; Kumar, V; Skvortsova, I; Kumar, V.Resistance to chemotherapy and relapse are major hurdles for the effective treatment of cancer. Major reason for this is a small sub population of cancer stem cells (CSCs) and its microenvironment. CSCs are critical driving force for several types of cancer, such as gastric, colon, breast and many more. Hence, for the complete eradication of cancer, it is necessary to develop therapeutic approaches that can specifically target CSCs. Chemical agents that target different proteins involved in CSC signaling pathways, either as single agent or simultaneously targeting two or more proteins have generated promising pre-clinical and clinical results. In the current review article, we have discussed various targets and cellular pathways that can be explored for the effective and complete eradication of CSCs. Some latest developments in the field of design, synthesis and screening of ligands to target cancer stem cells have been summarized in the current review article. � 2020 Bentham Science Publishers.Item Epidermal growth factor receptor and its trafficking regulation by acetylation: Implication in resistance and exploring the newer therapeutic avenues in cancer(Bentham Science Publishers, 2020) Kumar, M; Joshi, G; Chatterjee, J; Kumar, R.Background: The EGFR is overexpressed in numerous cancers. So, it becomes one of the most favorable drug targets. Single-acting EGFR inhibitors on prolong use induce resistance and side effects. Inhibition of EGFR and/or its interacting proteins by dual/combined/multitargeted therapies can deliver more efficacious drugs with less or no resistance. Objective: The review delves deeper to cover the aspects of EGFR mediated endocytosis, leading to its trafficking, internalization, and crosstalk(s) with HDACs. Methods and Results: This review is put forth to congregate relevant literature evidenced on EGFR, its impact on cancer prognosis, inhibitors, and its trafficking regulation by acetylation along with the current strategies involved in targeting these proteins (EGFR and HDACs) successfully by involving dual/hybrid/combination chemotherapy. Conclusion: The current information on cross-talk of EGFR and HDACs would likely assist researchers in designing and developing dual or multitargeted inhibitors through combining the required pharmacophores. � 2020 Bentham Science Publishers.Item A review on quinoline derivatives as anti-methicillin resistant Staphylococcus aureus (MRSA) agents(BioMed Central Ltd., 2020) Kumar, P.Methicillin Resistant Staphylococcus aureus (MRSA) consists of strains of S. aureus which are resistant to methicillin. The resistance is due to the acquisition of mecA gene which encodes PBP2a unlike of any PBPs normally produced by S. aureus. PBP2a shows unusually low ?-Lactam affinity and remains active to allow cell wall synthesis at normally lethal ?-Lactam concentrations. MRSA can cause different types of infections like Healthcare associated MRSA, Community associated MRSA and Livestock associated MRSA infections. It causes skin lesions, osteomyelitis, endocarditis and furunculosis. To treat MRSA infections, only a few options are available like vancomycin, clindamycin, co-trimoxazole, fluoroquinolones or minocycline and there is a dire need of discovering new antibacterial agents that can effectively treat MRSA infections. In the current review, an attempt has been made to compile the data of quinoline derivatives possessing anti-MRSA potential reported to date.[Figure not available: see fulltext.] � 2020 The Author(s).Item Protective Effect of Hemin Against Experimental Chronic Fatigue Syndrome in Mice: Possible Role of Neurotransmitters(Springer, 2020) Thakur, V; Jamwal, S; Kumar, M; Rahi, V; Kumar, P.Chronic fatigue syndrome (CFS) is a disorder characterized by persistent and relapsing fatigue along with long-lasting and debilitating fatigue, myalgia, cognitive impairment, and many other common symptoms. The present study was conducted to explore the protective effect of hemin on CFS in experimental mice. Male albino mice were subjected to stress-induced CFS in a forced swimming test apparatus for 21 days. After animals had been subjected to the forced swimming test, hemin (5 and 10 mg/kg; i.p.) and hemin (10 mg/kg) + tin(IV) protoporphyrin (SnPP), a hemeoxygenase-1 (HO-1) enzyme inhibitor, were administered daily for 21 days. Various behavioral tests (immobility period, locomotor activity, grip strength, and anxiety) and estimations of biochemical parameters (lipid peroxidation, nitrite, and GSH), mitochondrial complex dysfunctions (complexes I and II), and neurotransmitters (dopamine, serotonin, and norepinephrine and their metabolites) were subsequently assessed. Animals exposed to 10 min of forced swimming session for 21 days showed a fatigue-like behavior (as increase in immobility period, decreased grip strength, and anxiety) and biochemical alteration observed by increased oxidative stress, mitochondrial dysfunction, and neurotransmitter level alteration. Treatment with hemin (5 and 10 mg/kg) for 21 days significantly improved the decreased immobility period, increased locomotor activity, and improved anxiety-like behavior, oxidative defense, mitochondrial complex dysfunction, and neurotransmitter level in the brain. Further, these observations were reversed by SnPP, suggesting that the antifatigue effect of hemin is HO-1 dependent. The present study highlights the protective role of hemin against experimental CFS-induced behavioral, biochemical, and neurotransmitter alterations. - 2020, Springer Science+Business Media, LLC, part of Springer Nature.Item Tetrazoles as anticancer agents: A review on synthetic strategies, mechanism of action and SAR studies(Elsevier, 2020) Dhiman, N; Kaur, K; Jaitak, VikasCancer is a leading cause of death worldwide. Even after the availability of numerous drugs and treatments in the market, scientists and researchers are focusing on new therapies because of their resistance and toxicity issues. The newly synthesized drug candidates are able to demonstrate in vitro activity but are unable to reach clinical trials due to their rapid metabolism and low bioavailability. Therefore there is an imperative requisite to expand novel anticancer negotiators with tremendous activity as well as in vivo efficacy. Tetrazole is a promising pharmacophore which is metabolically more stable and acts as a bioisosteric analogue for many functional groups. Tetrazole fragment is often castoff with other pharmacophores in the expansion of novel anticancer drugs. This is the first systematic review that emphasizes on contemporary strategies used for the inclusion of tetrazole moiety, mechanistic targets along with comprehensive structural activity relationship studies to provide perspective into the rational design of high-efficiency tetrazole-based anticancer drug candidates. - 2020 Elsevier LtdItem Global trends in pesticides: A looming threat and viable alternatives(Academic Press, 2020) Sharma, A; Shukla, A; Attri, K; Kumar, M; Kumar, P; Suttee, A; Singh, G; Barnwal, R.P; Singla, N.Pesticides are widely used chemical compounds in agriculture to destroy insects, pests and weeds. In modern era, they form an indispensable part of agricultural and health practices. Globally, nearly 3 billion kg of pesticides are used every year with a budget of ~40 billion USD. This extensive usage has increased the crop yield as well as led to significant reduction in harvest losses and thereby, enhanced food availability. On the other hand, indiscriminate usage of these chemicals has led to several environmental implications and caused adverse effects on human health. Epidemiological evidences have revealed the harmful effects of pesticides exposure on various organs including liver, brain, lungs and colon. Recent investigations have shown that pesticides can also lead to fatal consequences such as cancer among individuals. These chemicals enter ecosystem, thus hampering the sensitive environmental equilibrium through bio-accumulation. Due to their non-biodegradable nature, they can persist in nature for years and are regarded as potent biohazard. Worldwide, very few surveillance methods have been considered, which can bring awareness among the individuals, therefore the present review is an attempt to delineate consequences induced by various types of pesticide exposure on the environment. Further, the prospective of biopesticides use could facilitate the increase of crop production without compromising human health.- 2020 Elsevier Inc.