Browsing by Author "Singh, P"

Now showing 1 - 3 of 3
  • No Thumbnail Available
    Item
    Drug-metabolizing enzymes: role in drug resistance in cancer
    (Springer, 2020) Kaur, G; Gupta, S.K; Singh, P; Ali, V; Kumar, V; Verma, M.
    Although continuous researches are going on for the discovery of new chemotherapeutic agents, resistance to these anticancer agents has made it really difficult to reach the fruitful results. There are many causes for this resistance that are being studied by the researchers across the world, but still, success is far because there are several factors that are going along unattended or have been studied less. Drug-metabolizing enzymes (DMEs) are one of these factors, on which less study has been conducted. DMEs include Phase I and Phase II enzymes. Cytochrome P450s (CYPs) are major Phase I enzymes while glutathione-S-transferases (GSTs), UDP-glucuronosyltransferases (UGTs), dihydropyrimidine dehydrogenases are the major enzymes belonging to the Phase II enzymes. These enzymes play an important role in detoxification of the xenobiotics as well as the metabolism of drugs, depending upon the tissue in which they are expressed. When present in tumorous tissues, they cause resistance by metabolizing the drugs and rendering them inactive. In this review, the role of these various enzymes in anticancer drug metabolism and the possibilities for overcoming the resistance have been discussed. � 2020, Federaci�n de Sociedades Espa�olas de Oncolog�a (FESEO).
  • Thumbnail Image
    Item
    Impact of rice-husk ash on the soil biophysical and agronomic parameters of wheat crop under a dry tropical ecosystem
    (Elsevier, 2019) Singh, R; Srivastava, P; Singh, P; Sharma, Archana Kumari; Singh, H; Raghubanshi, A.S.
    Several alternative amendments like organic manure and biochar have been proposed for revitalizing the degrading soil viability and fertility for sustainable agriculture, globally. However, detailed field-scale studies focussing on the soil and agronomic parameters of crops under these amendments are limited in dry tropical ecosystems. Therefore, we studied the impact of various soil amendments viz., rice-husk ash (RHA) and farm-yard manure (FYM) along with mineral fertilizer on soil biophysical and agronomic parameters of wheat crop. We specifically explored the impact of the amendments on soil CO2 efflux (SCE, under different growth stages) and the harvest index of wheat crop, which are considered as the key indicators of soil viability and agronomic efficiency, respectively. SCE, soil moisture, soil temperature, soil N, microbial biomass and soil pH were found significantly varying under different treatments (P < 0.05). SCE was found maximum under sole FYM applied and minimum under mineral fertilizer applied treatments, whereas RHA application lowered the SCE as compared to sole FYM application. Moreover, SCE showed variation with plant growth stages, and found maximum during stem elongation followed by heading stage whereas minimum during ripening stage. Soil moisture was found to have considerable regulation for the overall variation in SCE (r2 = 0.17; P = 0.04). In contrast to the soil properties, agronomic parameters (except harvest index) were found higher under mineral fertilizer applied treatments followed by sole FYM and combined FYM + RHA treatments, whereas sole RHA applied treatment showed minimum values. However, significant variations were observed only for harvest index, aboveground dry matter, grain and straw yields (P < 0.05). Further, harvest index was found highest under sole and combined FYM and RHA applied treatments whereas lowest in mineral fertilizer applied treatments. Soil C/N ratio (r2 = 0.16; P = 0.04) and panicle length (r2 = 0.18; P = 0.03), respectively as soil and agronomic parameters, have been found to have considerable control over harvest index. The findings revealed that soil viability is higher under sole FYM and combined FYM + RHA treatments whereas mineral fertilization enhances agronomic performance. Based on the studied two indicators, we conclude that both soil and agronomic sustainability can be maintained by using a combination of organic (FYM and RHA) fertilization with reduced inputs from mineral fertilizers. However, it further needs exploration for various soil and plant eco-physiological parameters of different crops at field level for wider adaptation in the dry tropical region. © 2018 Elsevier Ltd
  • No Thumbnail Available
    Item
    Molecular docking and in vitro study of Syzygium cumini-derived natural compounds on receptor tyrosine kinases pathway components
    (Inderscience Enterprises Ltd., 2019) Singh, P; Bast, Felix; Bhushan, S; Mehra, R; Kamboj, P.
    Syzygium cumini (S. cumini) is used for a variety of biological activities such as anti-inflammatory, anti-diabetic and anti-oxidant; currently, it has been reported for DNA protecting activity against radiation damage. Receptor tyrosine kinases (RTKs) are identified as critical regulators of various cellular processes including cell proliferation, metabolism and apoptosis. These receptors have recently gained attention as an attractive target for cancer treatment. The present research was aimed to screen S. cumini-derived natural compounds against RTKs pathway components using molecular docking. Furthermore, in vitro anti-proliferative 3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and anti-oxidative (nitro blue tetrazolium and H 2 CDFD) activities of leaf extract of S. cumini are also reported. Selected natural compounds were docked with X-ray crystal structure of RTKs signalling proteins using grid-based ligand docking with energetics Maestro 9.6. In the present investigation, our result highlighted that myricetin, kaempferol, delphinidin chloride, ellagic acid, rutin, petunidin, gossypol and mirtillin generated a good dock score with all selected proteins. Protein-ligand interactions accentuated that several bonds such as lipophilic, hydrogen bonding, π-π stacking and cation-π interactions represent a ruling contribution at the active site. Moreover, reduction in cell viability with leaf extract of S. cumini treatment at concentrations of 5-80 µg/ml after 48 h in MCF-7 cells was observed. Leaf extract of S. cumini significantly reduced the Reactive oxygen species (ROS) generation in MCF-7 cells after 48 h. These results indicate the anti-cancer potential of S. cumini. Thus, isolation and purification of anti-cancerous compounds are suggested to explore more possibilities in the field. © 2019 Inderscience Enterprises Ltd.