Rituraj Konwar

Academy of Scientific and Innovative Research, New Dilli, NCT, India

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Publications (58)150.1 Total impact

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    ABSTRACT: We report herein the design and synthesis of bioisosteres of spirooxindole (MI-63/219) , a small-molecule inhibitors of the MDM2-p53 interaction as anti-breast cancer agents. Compound 5b has been exhibiting significant anti-proliferative activity in nude mice bearing MCF-7 xenograft tumor. The compound 5b was found to act via modulation of MDM2 and p53 expression in breast cancer cells expressing wild type p53. Compound 5b stimulated p53 activation, caused modulation of downstream effectors p21, pRb, and cyclinD1 which regulate cell cycle. Thus, compound triggered G1-S phase cell cycle arrest, which was evident by flow cytometric analysis of treated breast cancer cells. Thus, compound 5b restores the p53 function, which triggers molecular events consistent with cell cycle arrest at G1/S phase.
    Bioorganic & Medicinal Chemistry 12/2014; · 2.95 Impact Factor
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    ABSTRACT: Microtubules are polar cytoskeletal filaments assembled from head-to-tail and comprised of lateral associations of α/β-tubulin heterodimers that play key role in various cellular processes. Because of their vital role in mitosis and various other cellular processes, microtubules have been attractive targets for several disease conditions and especially for cancer. Antitubulin is the most successful class of antimitotic agents in cancer chemotherapeutics. The target recognition of antimitotic agents as a ligand is not much explored so far. However, 3,4,5-trimethoxyphenyl fragment has been much highlighted and discussed in such type of interactions. In this review, some of the most important naturally occurring antimitotic agents and their interactions with microtubules are discussed with a special emphasis on the role of 3,4,5-trimethoxyphenyl unit. At last, some emerging naturally occurring antimitotic agents have also been tabulated.
    Bioorganic & Medicinal Chemistry 12/2014; · 2.95 Impact Factor
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    ABSTRACT: An attempt has been made to use curcumin (CUR) in combination with Etoposide (ETP) by encapsulating in nanoemulsion, as two tier approach i.e., to evaluate improvement in efficacy of ETP on prostate cancer cells (PC3 and DU145) and to assess their effect on cross-talk between osteoblast and tumor cells leading to metastatic cascade in bones. Nanoemulsion was developed and evaluated for size, charge, in-vitro drug release and anticancer activity, effect on cross talk between osteoblast and prostate cancer cells and pharmacokinetics in rats. The entrapment efficiency of both ETP and CUR in nanoemulsion was more than 98% while the globule size was less than 150 nm with zeta potential –29.8 mV. The percent inhibition in case of ETP and ETP: CUR (1:3 w/w) was 55.92 ± 1.2 and 41.13 ± 2.4% (at 5 μ M) respectively when tested in PC3 cells. DU-145 seemed to be less responsive in comparison to PC3 cells both in respect of ETP and their mixture (ETP + CUR). Our data shows that CUR and ETP after encapsulation in nanoemulsion (F5) were effectively delivered intracellularly in PC3 cells and the cytotoxicity of F5 was enhanced by 1.5 fold as compared to ETP + CUR at 5 μ M concentration. It has also been observed that mice calvarial osteoblasts cultured and incubated with PC-3 and DU-145 cells conditioned media induces inhibition of osteoblast differentiation event. While this inhibition was significantly reversed by F5 at 5 μ M concentration over other treated groups, the pharmacokinetic profile of both ETP and CUR was also significantly improved when administered in nanoemulsion.
    Journal of Biomedical Nanotechnology 11/2014; 10(11):3381-3391. · 7.58 Impact Factor
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    ABSTRACT: A new series of 2-(alkoxy(hydroxy)phosphoryloxy)ethyl dialkylcarbodithioate derivatives was synthesized and evaluated against endocrine related cancers, acting via modulation of Akt-pathway. Eighteen compounds were active at 7.24-100 μM against MDA-MB-231 or MCF-7 cell lines of breast cancer. Three compounds (14, 18 and 22) were active against MCF-7 cells at IC50 significantly better than miltefosine and most of the compounds were less toxic towards non-cancer cell lines, HEK-293. On the other hand, twelve compounds exhibited cell growth inhibiting activity against prostate cancer cell lines, either PC-3 or DU-145 at 14.69-95.20 μM. While nine of these were active against both cell lines. The most promising compounds 14 and 18 were about two and five fold more active than miltefosine against DU-145 and MCF-7 cell lines respectively and significantly down regulated phospho-Akt. Possibly anti-cancer and pro-apoptotic activity was mostly due to blockade of Akt-pathway.
    European Journal of Medicinal Chemistry 10/2014; · 3.43 Impact Factor
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    ABSTRACT: BACKGROUND: Free copper in Wilson disease (WD) is toxic and may reduce antioxidant, increase oxidative stress marker and thereby cytokine release and excitotoxic injury, but there is paucity of studies in humans. We report oxidative stress markers, cytokines and glutamate in neurologic WD and correlate these with their clinical severity, laboratory findings and extent of Magnetic resonance imaging (MRI) changes. METHODS: 29 patients with neurologic WD and 9 asymptomatic WD siblings were included and their clinical, treatment history, disease severity, biochemical findings and MRI changes were noted. Glutathione (GSH), total antioxidant capacity (TAC) and malonodialdehyde (MDA) were measured by spectrophotometer, cytokines by cytokine bead array and glutamate by the fluorometer. RESULTS: In WD patients, the glutathione (mean±SEM, 2.20±0.06 vs. 2.73±0.04mg/dl, P<0.001) and TAC (1.70±0.03 vs. 2.29±0.02 Trolox_Eq_mmol/l, P<0.001) were reduced, and MDA and glutamate (23.93±0.54 vs. 19.96±0.27μmol/l; P<0.001) were increased (4.7±0.11 vs. 3.03±0.52nmol/ml, P<0.001) compared to controls. The serum IL6 {median (IQRs), 9.42(10.92) vs. 5.2(5.34) pg/ml; P=0.001}, IL8 {12.37(10.92) vs. 5.63(5.52) pg/ml; P<0.001}, IL10 {8.33(8.3) vs. 2.05(1.37) pg/ml; P=0.001} and TNFα {6.14(8.95) vs. 3.61(3.58) pg/ml; P<0.001} were also increased in WD patients compared to controls. These changes were more marked in the neurologic WD compared to asymptomatic WD and in the untreated compared to treated patients. TAC correlated with duration of illness, serum free copper, 24hour urinary copper and serum ceruloplasmin, and glutamate with MDA, TNFα, ceruloplasmin and 24-hour urinary copper.
    Journal of Neuroimmunology 09/2014; · 2.79 Impact Factor
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    ABSTRACT: a b s t r a c t 2-Methoxyestradiol (2ME2) is an investigational anticancer drug. In the present study, 2-alkoxyesters/ acid and 2-benzyloxy analogues of estradiol have been synthesized as analogues of 2ME2. Three of the derivatives exhibited significant anticancer activity against human breast cancer cell lines. The best analogue of the series i.e. 24 showed stabilization of tubulin polymerisation process. It was substantiated by confocal microscopy and molecular docking studies where 24 occupied 'paclitaxel binding pocket' to stabilize the polymerisation process. Compound 24 significantly inhibited MDA-MB-231 cells (IC 50 : 7 mM) and induced arrest of cell cycle and apoptosis in MDA-MB-231 cells. In acute oral toxicity, 24 was found to be non-toxic and well tolerated in Swiss albino mice up to 1000 mg/kg dose.
    European Journal of Medicinal Chemistry 09/2014; · 3.43 Impact Factor
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    ABSTRACT: Employing a rational design of Thioaryl naphthylmethanone oxime ether analogs containing functional properties of various anti-cancer drugs, a series of compounds were identified that displayed potent cytotoxicity towards various cancer cells, out of which, 4-(methylthio)phenyl)(naphthalen-1-yl)methanoneO-2-(diethylamino)ethyl oxime (MND) exhibited best safety profile. MND induced apoptosis, inhibited migration and invasion, strongly inhibited cancer stem cell population on a par with salinomycin, and demonstrated orally potent tumor regression in mouse MCF-7 xenografts. Mechanistic studies revealed that MND strongly abrogated EGF-induced proliferation, migration and tyrosine kinase (TK) signaling in breast cancer cells. However, MND failed to directly inhibit EGFR or other related receptor TKs in a cell-free system. Systematic investigation of putative target upstream of EGFR revealed that the biological effects of MND could be abrogated by pertussis toxin. Together, MND represents a new nonquinazoline class having a substantial antiproliferative effect on breast cancer cells by likely involvement of a Gαi/0-coupled serpentine receptor.
    Journal of Medicinal Chemistry 09/2014; 57(19):8010-8025. · 5.48 Impact Factor
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    ABSTRACT: Background Free copper in Wilson disease (WD) is toxic and may reduce antioxidant, increase oxidative stress marker and thereby cytokine release and excitotoxic injury, but there is paucity of studies in humans. We report oxidative stress markers, cytokines and glutamate in neurologic WD and correlate these with their clinical severity, laboratory findings and extent of Magnetic resonance imaging (MRI) changes. Methods 29 patients with neurologic WD and 9 asymptomatic WD siblings were included and their clinical, treatment history, disease severity, biochemical findings and MRI changes were noted. Glutathione (GSH), total antioxidant capacity (TAC) and malonodialdehyde (MDA) were measured by spectrophotometer, cytokines by cytokine bead array and glutamate by the fluorometer. Results In WD patients, the glutathione (Mean ± SEM, 2.20 ± 0.06Vs2.73 ± 0.04 mg/dl, P < 0.001) and TAC (1.70 ± 0.03 Vs.2.29 ± 0.02 Trolox_Eq_mmol/L, P < 0.001) were reduced, and MDA and glutamate (23.93 ± 0.54Vs. 19.96 ± 0.27 μmol/l; P < 0.001) were increased (4.7 ± 0.11Vs. 3.03 ± 0.52 nmol/ml, P < 0.001) compared to controls. The serum IL6 {median (IQRs), 9.42(10.92) Vs. 5.2(5.34) pg/ml; P = 0.001}, IL8 {12.37(10.92) Vs. 5.63(5.52) pg/ml; P < 0.001}, IL10 {8.33(8.3) Vs. 2.05(1.37) pg/ml; P = 0.001} and TNFα {6.14(8.95) Vs. 3.61(3.58) pg/ml; P < 0.001} were also increased in WD patients compared to controls. These changes were more marked in the neurologic WD compared to asymptomatic WD and in the untreated compared to treated patients. TAC correlated with duration of illness, serum free copper, 24 hour urinary copper and serum ceruloplasmin, and glutamate with MDA, TNFα, ceruloplasmin and 24-hour urinary copper. Conclusions In WD patients, antioxidants are reduced and MDA, cytokines and glutamate are increased which are more marked in symptomatic neurologic WD than asymptomatic patients.
    Journal of Neuroimmunology 09/2014; · 2.79 Impact Factor
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    ABSTRACT: Tumour infiltrating lymphocytes (TILs) represent the host immune response against cancer cells associated with good or bad prognosis in different tumour types. This study was undertaken to evaluate the significance of CD3+, CD4+ and CD8+ TILs in breast cancer tissues in relation to clinico-pathological variables and survival outcome.
    The Indian journal of medical research. 09/2014; 140(3):361-9.
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    ABSTRACT: A new series of 2-(alkoxy(hydroxy)phosphoryloxy)ethyl dialkylcarbodithioate derivatives was synthesized and evaluated against endocrine related cancers, acting via modulation of Akt-pathway. Eighteen compounds were active at 7.24-100 μM against MDA-MB-231 or MCF-7 cell lines of breast cancer. Three compounds (14, 18 and 22) were active against MCF-7 cells at IC50 significantly better than miltefosine and most of the compounds were less toxic towards non-cancer cell lines, HEK-293. On the other hand, twelve compounds exhibited cell growth inhibiting activity against prostate cancer cell lines, either PC-3 or DU-145 at 14.69-95.20 μM. While nine of these were active against both cell lines. The most promising compounds 14 and 18 were about two and five fold more active than miltefosine against DU-145 and MCF-7 cell lines respectively and significantly down regulated phospho-Akt. Possibly anti-cancer and pro-apoptotic activity was mostly due to blockade of Akt-pathway.
    European Journal of Medicinal Chemistry 08/2014; 85C:638-647. · 3.43 Impact Factor
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    ABSTRACT: Synthesis and bioevaluation of a novel γ-(triazolyl ethylidene)butenolides and consequent pyrrolinones is reported. In which, compound 25 showed potent activity (IC50 = 11.3 μM) against MDA-MB-231 cells in vitro.
    European Journal of Medicinal Chemistry 07/2014; 82:106–119. · 3.43 Impact Factor
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    ABSTRACT: A series of novel γ-(triazolyl ethylidene)butenolides (4-23) were prepared from commercially available l-ascorbic acid in good yields. These butenolides on reaction with ethanolic ammonia/amines led to formation of respective 5-hydroxy pyrrolinones (24-33). The two of these pyrrolinones on dehydration with p-toluenesulfonic acid, were transformed into γ-(triazolyl ethylidene)pyrrolinones (34, 35). Among all the newly synthesized hybrid molecules tested for anticancer activity in vitro, compounds 24, 25, 26, 27, 28, 30 and 32 showed significant activity against MCF-7, MDA-MB-231, PC-3 or U-937 cells. In particular compound 25 (IC50 = 11.3 μM) exhibited most potent activity against breast cancer cells and preliminary studies revealed that potency of this compound is due to ROS generation, subsequent activation of p38, leading to apoptosis and inhibition of cancer cells.
    European Journal of Medicinal Chemistry 05/2014; 82C:106-119. · 3.43 Impact Factor
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    ABSTRACT: Tubulin is a well established target for anticancer drug development. Lignans and neolignans were synthesized as tubulin interacting agents. Neolignans 10 and 19 exhibited significant anticancer activity against MCF-7 and MDAMB-231 human breast cancer cell lines. Both the compounds effectively induced stabilization of microtubule at 4 and 20μM concentrations respectively. Neolignan 10 induced G2/M phase arrest in MCF-7 cells. Docking experiments raveled that 10 and 19 occupied the same binding pocket of paclitaxel with some difference in active site amino acids and good bioavailability of both the compounds. In in vivo acute oral toxicity 10 was well tolerated up to 300mg/kg dose in Swiss-albino mice.
    Bioorganic & medicinal chemistry 01/2014; · 2.82 Impact Factor
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    ABSTRACT: TGF-β1 is a multi-functional cytokine that plays an important role in breast carcinogenesis. Critical role of TGF-β1 signaling in breast cancer progression is well documented. Some TGF-β1 polymorphisms influence its expression; however, their impact on breast cancer risk is not clear. We analyzed 1222 samples in a candidate gene-based genetic association study on two distantly located and ethnically divergent case-control groups of Indian women, followed by a population-based genetic epidemiology study analyzing these polymorphisms in other Indian populations. The c.29C>T (Pro10Leu, rs1982073 or rs1800470) and c.74G>C (Arg25Pro, rs1800471) polymorphisms in the TGF-β1 gene were analyzed using direct DNA sequencing, and peripheral level of TGF-β1 were measured by ELISA. c.29C>T substitution increased breast cancer risk, irrespective of ethnicity and menopausal status. On the other hand, c.74G>C substitution reduced breast cancer risk significantly in the north Indian group (p = 0.0005) and only in the pre-menopausal women. The protective effect of c.74G>C polymorphism may be ethnicity-specific, as no association was seen in south Indian group. The polymorphic status of c.29C>T was comparable among Indo-Europeans, Dravidians, and Tibeto-Burmans. Interestingly, we found that Tibeto-Burmans lack polymorphism at c.74G>C locus as true for the Chinese populations. However, the Brahmins of Nepal (Indo-Europeans) showed polymorphism in 2.08% of alleles. Mean TGF-β1 was significantly elevated in patients in comparison to controls (p<0.001). c.29C>T and c.74G>C polymorphisms in the TGF-β1 gene significantly affect breast cancer risk, which correlates with elevated TGF-β1 level in the patients. The c.29C>T locus is polymorphic across ethnically different populations, but c.74G>C locus is monomorphic in Tibeto-Burmans and polymorphic in other Indian populations.
    PLoS ONE 10/2013; 8(10):e75979. · 3.53 Impact Factor
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    ABSTRACT: Two series of new benzoxazepines substituted with different alkyl amino ethyl chains were synthesized comprising synthetic steps of inter and intramolecular Mitsunobu reaction, lithium aluminium hydride (LAH) reduction, debenzylation, bimolecular nucleophilic substitution (SN2) reaction. The present study investigates the effect of a tyrosine-based benzoxazepine derivative in human breast cancer cells MCF-7 and MDA-MB-231 and in breast cancer animal model. The anti-proliferative effect of 15a on MCF-7 cells was associated with G1 cell-cycle arrest. This G1 growth arrest was followed by apoptosis as 15a dose dependently increased phosphatidylserine exposure, PARP cleavage and DNA fragmentation that are hallmarks of apoptotic cell death. Interestingly, 15a activated components of both intrinsic and extrinsic pathways of apoptosis characterized by activation of caspase-8 and -9, mitochondrial membrane depolarization and increase in Bax/Bcl2 ratio. However, use of selective caspase inhibitors revealed that the caspase-8-dependent pathway is the major contributor to 15a-induced apoptosis. Compound 15a also significantly reduced the growth of MCF-7 xenograft tumors in athymic nude mice. Together, 15a could serve as a base for the development of a new group of effective breast cancer therapeutics.
    Bioorganic & medicinal chemistry letters 10/2013; · 2.65 Impact Factor
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    ABSTRACT: Nanocarriers can be surface engineered to increase endocytosis for applications in delivery of chemotherapeutics. This study investigated the chitosan (CS)-mediated effects on the anticancer efficacy and uptake of docetaxel-loaded nanometric particles (<250 nm) by MCF-7 tumor cells. Herein, negatively charged poly lactic-co-glycolic acid (PLGA) nanoparticles (−18.4 ± 2.57 mV, 162 ± 6.34 nm), poorly endocytosed by the MCF-7 cells, were subjected to surface modification with CS. It demonstrated significant increase (>5-fold) in intracellular uptake as well as antitumor efficacy of modified nanoparticles (NPs) that explicate the possibility of saccharide marker-mediated tumor targeting along with synergism via proapoptotic effect of CS. Additionally, high positivity of optimized tailored nanocarrier (+23.3 ± 2.02 mV, 242.8 ± 9.42 nm) may have accounted for the increased adsorption-mediated endocytosis, preferably toward tumor cells with negative potential. Developed drug carrier system showed high stability in human blood which is in compliance with mucoadhesive property of CS. Transmission electron microscopy technique was applied to observe shape and morphological features of NPs. Furthermore, in vivo tissue toxicity study revealed safe use of drug at 20 mg/kg dose in nanoparticulate form. Moreover, the enhanced in vitro uptake of these NPs and their cytotoxicity against the tumor cells along with synergistic effect of CS clearly suggest that CS-modified carrier system is a promising candidate for preclinical studies to achieve wider anti-tumor therapeutic window and lower side effects.
    Journal of Nanoparticle Research 09/2013; 15(9). · 2.28 Impact Factor
  • PLoS ONE 07/2013; · 3.53 Impact Factor
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    ABSTRACT: Inhibition of epidermal growth factor receptor (EGFR) signaling is considered to be a promising treatment strategy for estrogen receptor (ER)-negative breast tumors. We have investigated here the anti-breast cancer properties of a novel anti-proliferative benzopyran compound namely, 2-[piperidinoethoxyphenyl]-3-phenyl-2H-benzo(b)pyran (CDRI-85/287) in ER- negative and EGFR- overexpressing breast cancer cells. The benzopyran compound selectively inhibited the EGF-induced growth of MDA-MB 231 cells and ER-negative primary breast cancer cell culture. The compound significantly reduced tumor growth in xenograft of MDA-MB 231 cells in nude mice. The compound displayed better binding affinity for EGFR than inhibitor AG1478 as demonstrated by molecular docking studies. CDRI-85/287 significantly inhibited the activation of EGFR and downstream effectors MEK/Erk and PI-3-K/Akt. Subsequent inhibition of AP-1 promoter activity resulted in decreased transcription activation and expression of c-fos and c-jun. Dephosphorylation of downstream effectors FOXO-3a and NF-κB led to increased expression of p27 and decreased expression of cyclin D1 which was responsible for decreased phosphorylation of Rb and prevented the transcription of E2F- dependent genes involved in cell cycle progression from G1/S phase. The compound induced apoptosis via mitochondrial pathway and it also inhibited EGF-induced invasion of MDA-MB 231 cells as evidenced by decreased activity of MMP-9 and expression of CTGF. These results indicate that benzopyran compound CDRI-85/287 could constitute a powerful new chemotherapeutic agent against ER-negative and EGFR over-expressing breast tumors.
    PLoS ONE 06/2013; · 3.53 Impact Factor
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    ABSTRACT: Gemcitabine (dFdC) mediated cancer treatment faces obstacles, due to its high hydrophilicity. A valuable strategy was executed by synthesizing lipophilic fatty acid derivative of dFdC i.e., 4-(N)-stearoyl gemcitabine (C18dFdC), built-in into polymeric poly-lactic-co-glycolic acid nanoparticles (PLGA NPs) and compared with that of parent drug. Encapsulation of derivative within NPs was higher (68.24 +/- 3.64%) than dFdC and showed comparatively sustained drug release (19.87 +/- 1.73% within 12 hours), with a proof of increased biological half life. The cytotoxicity and flow cytometric analysis displayed enhanced MCF-7 cell inhibition by C18dFdC-NPs with higher uptake compared to dFdC-NPs. Interestingly, like gemcitabine, C18dFdC-NPs did not induce appreciable differences in blood parameters and in vivo tissue toxicity study demonstrating safe use of derivative at 40 mg/kg dose. In conclusion, the preclinical data obtained in vitro and in vivo demonstrate the C18dFdC-nanocarrier as an advantageous and promising delivery system for cancer treatment along with the potential to improve the clinical outcome of gemcitabine chemotherapy.
    Journal of Biomedical Nanotechnology 05/2013; 9(5):915-25. · 7.58 Impact Factor
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    ABSTRACT: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Publication Stats

351 Citations
150.10 Total Impact Points

Institutions

  • 2014
    • Academy of Scientific and Innovative Research
      New Dilli, NCT, India
  • 2011–2014
    • CSIR Central Road Research Institute
      New Dilli, NCT, India
    • American Association of Oral and Maxillofacial Surgeons
      India Hook, South Carolina, United States
  • 2007–2014
    • Central Drug Research Institute
      • • Medicinal and Process Chemistry Division (CDRI)
      • • Endocrinology Division (CDRI)
      Lakhnau, Uttar Pradesh, India
  • 2010
    • The Ohio State University
      Columbus, Ohio, United States
  • 2008–2009
    • University of Lucknow
      • Department of Zoology
      Lucknow, Uttar Pradesh, India