Catalogue Search | MBRL
Search Results Heading
Explore the vast range of titles available.
MBRLSearchResults
-
DisciplineDiscipline
-
Is Peer ReviewedIs Peer Reviewed
-
Item TypeItem Type
-
SubjectSubject
-
YearFrom:-To:
-
More FiltersMore FiltersSourceLanguage
Done
Filters
Reset
1,080
result(s) for
"Divya, Singh"
Sort by:
Assessment of malathion toxicity on cytophysiological activity, DNA damage and antioxidant enzymes in root of Allium cepa model
2020
The current study was emphasized to assess the effect of malathion on root system (cell division and kinetics of the root elongation) and stress related parameters in
Allium cepa
L. The roots were exposed to different concentrations (0.05, 0.13, 0.26, 0.39 and 0.52 g/L) of malathion for different treatment periods (4, 8 and 18 h). The results revealed that malathion application affected the growth rate and cell division in root tips. The root elongation kinetics were impaired at 0.13 to 0.52 g/L concentrations. Reduction in tissue water content (TWC) indicated the limited osmotic adjustment due to membrane damage. Further, a decrease in sucrose content was observed in contrast to the accumulation of proline (upto 0.39 g/L). Moreover, malathion exposure elevated the levels of lipid peroxidation followed by changes in antioxidant enzymes status. The activities of ascorbate peroxidase (APX) and glutathione reductase (GR) were down-regulated whereas the activities of catalase (CAT), glutathione-S-transferase (GST) and superoxide dismutase (SOD) were up-regulated except in 0.52 g/L malathion. The molecular docking study of malathion with CAT, GST, SOD, APX and GR also supported of above results for their activity. All these physiological responses varied with increasing malathion concentration and duration of treatment. The single cell gel electrophoresis results showed that all concentrations of malathion induced DNA damage in root cells. The findings depicted that malathion application induces cytotoxic and phytotoxic effects mediated through oxidative stress and subsequent injuries.
Journal Article
Monitoring genotoxic, biochemical and morphotoxic potential of penoxsulam and the protective role of European blueberry (Vaccinium myrtillus L.) extract
2023
The present study aimed at exploring to explore the penoxsulam toxicity and protective effects of blueberry extract in roots of
Allium cepa
L. The effective concentration (EC
50
) of penoxsulam was determined at 20 µg/L by the root growth inhibition test as the concentration reducing the root length by 50%. The bulbs of
A. cepa
L. were treated with tap water, blueberry extracts (25 and 50 mg/L), penoxsulam (20 µg/L) and combination of blueberry extracts (25 and 50 mg/L) with penoxsulam (20 µg/L) for 96 h. The results revealed that penoxsulam exposure inhibited cell division, rooting percentage, growth rate, root length and weight gain in the roots of
A. cepa
L. In addition, it induced chromosomal anomalies such as sticky chromosome, fragment, unequal distribution of chromatin, bridge, vagrant chromosome and c-mitosis and DNA strand breaks. Further, penoxsulam treatment enhanced malondialdehyde content and SOD, CAT and GR antioxidant enzyme activities. Molecular docking results supported the up-regulation of antioxidant enzyme SOD, CAT and GR. Against all these toxicity, blueberry extracts reduced penoxsulam toxicity in a concentration-dependent manner. The highest amount of recovery for cytological, morphological and oxidative stress parameters was observed when using blueberry extract at a concentration of 50 mg/L. In addition, blueberry extracts application showed a positive correlation with weight gain, root length, mitotic index and rooting percentage whereas a negative correlation with micronucleus formation, DNA damage, chromosomal aberrations, antioxidant enzymes activities and lipid peroxidation indicating its protecting effects. As a result, it has been seen that the blueberry extract can tolerate all these toxic effects of penoxsulam depending on the concentration, and it has been understood that it is a good protective natural product against such chemical exposures.
Journal Article
High-order Michaelis-Menten equations allow inference of hidden kinetic parameters in enzyme catalysis
2025
Single-molecule measurements provide a platform for investigating the dynamical properties of enzymatic reactions. To this end, the single-molecule Michaelis-Menten equation was instrumental as it asserts that the first moment of the enzymatic turnover time depends linearly on the reciprocal of the substrate concentration. This, in turn, provides robust and convenient means to determine the maximal turnover rate and the Michaelis-Menten constant. Yet, the information provided by these parameters is incomplete and does not allow access to key observables such as the lifetime of the enzyme-substrate complex, the rate of substrate-enzyme binding, and the probability of successful product formation. Here we show that these quantities and others can be inferred via a set of high-order Michaelis-Menten equations that we derive. These equations capture universal linear relations between the reciprocal of the substrate concentration and distinguished combinations of turnover time moments, essentially generalizing the Michaelis-Menten equation to moments of any order. We demonstrate how key observables such as the lifetime of the enzyme-substrate complex, the rate of substrate-enzyme binding, and the probability of successful product formation, can all be inferred using these high-order Michaelis-Menten equations. We test our inference procedure to show that it is robust, producing accurate results with only several thousand turnover events per substrate concentration.
Traditional approaches provide limited information on enzyme kinetics. Here, the authors derive high-order Michaelis-Menten equations, enabling inference of hidden parameters like binding rates and enzyme-substrate lifetimes, advancing enzymology beyond classical methods.
Journal Article
Octanoic acid a major component of widely consumed medium-chain triglyceride ketogenic diet is detrimental to bone
2021
Octanoic acid is a medium-chained saturated fatty acid found abundantly in the ketogenic dietary supplements containing medium chained triglycerides (MCT) along with decanoic acid. The MCT ketogenic diet is commonly consumed for weight loss but has also showcased neuroprotective potential against neurodegenerative disorders. However, recent clinical findings have reported a critical disadvantage with the long-term consumption of ketogenic diet i.e. bone loss. The following study was employed to investigate whether the two major components of MCT diet also possess bone loss potential as observed with classical ketogenic diet. Swiss albino mice aged between 10 and 12 weeks, were divided into 3 treatment groups that were administered with oral suspensions of octanoic acid, decanoic acid and a combination of both for 4 weeks. Bone specific markers, microarchitectural parameters, using micro computed tomography, and biomechanical strength were analyzed. Remarkably deleterious alterations in the trabecular bone microarchitecture, and on bone markers were observed in the octanoic acid treated groups. Our results suggest significant negative effects on bone health by octanoic acid. These findings require further investigation and validation in order to provide significant clinically relevant data to possibly modify dietary composition of the MCT ketogenic diet.
Journal Article
Impact of Irrigation Using Water Containing CuO and ZnO Nanoparticles on Spinach oleracea Grown in Soil Media
2016
Wastewater reuse is an important adaptation option for mitigating water stress in rapidly growing urban centers. Reuse potential of nanoparticles (NPs) contaminated wastewater for irrigation of
Spinacia oleracea
grown in soil media were assessed in this study. Irrigation of plant were done with water containing CuO and ZnO NPs as single compound and in binary mixture (10, 100, 1000 mg/L) till 11 weeks. At 1000 mg/L, reduction in root length: 16 %, 12 % and 18 %, shoot length: 22 %, 16 % and 27 %, total weight 37 %, 27 % and 45 %, chlorophyll: 18 %, 7 % and 29 % and carotenoids: 46 %, 33 % and 54 % were found for CuO NPs, ZnO NPs and binary mixture of NPs respectively. Uptake values were found to be 5.65 ± 0.8 Zn
2+
and 3.48 ± 0.75 Cu
2+
mg/g for the case of ZnO and CuO NPs respectively (at 1000 mg/L). For mixture of NPs, uptake of 3.18 ± 1.05 mg/g of Cu
2+
and 3.18 ± 1.05 mg/g of Zn
2+
ions were found. The results shows that water containing low concentration of NPs (10 mg/L) can be used for irrigating spinach grown in soil media as no significant toxic effect on growth and uptake of metal ion were found as compared to control. The results of this study evaluated the suitability of reusing water contaminated with NPs in agriculture. Further studies are however required to understand the toxic mode of action of mixture of NPs on growth and uptake mechanisms.
Journal Article
Assessment of the ameliorative effect of curcumin on pendimethalin-induced genetic and biochemical toxicity
2022
The present study aimed to assess the toxic effects of pendimethalin herbicide and protective role of curcumin using the
Allium
test on cytological, biochemical and physiological parameters. The effective concentration (EC
50
) of pendimethalin was determined at 12 mg/L by the root growth inhibition test as the concentration reducing the root length by 50%. The roots of
Allium cepa
L. was treated with tap water (group I), 5 mg/L curcumin (group II), 10 mg/L curcumin (group III), 12 mg/L pendimethalin (group IV), 12 mg/L pendimethalin + 5 mg/L curcumin (group V) and 12 mg/L pendimethalin + 10 mg/L curcumin (group VI). The cytological (mitotic index, chromosomal abnormalities and DNA damage), physiological (rooting percentage, root length, growth rate and weight gain) and oxidative stress (malondialdehyde level, superoxide dismutase level, catalase level and glutathione reductase level) indicators were determined after 96 h of treatment. The results revealed that pendimethalin treatment reduced rooting percentage, root length, growth rate and weight gain whereas induced chromosomal abnormalities and DNA damage in roots of
A. cepa
L. Further, pendimethalin exposure elevated malondialdehyde level followed by antioxidant enzymes. The activities of superoxide dismutase and catalase were up-regulated and glutathione reductase was down-regulated. The molecular docking supported the antioxidant enzymes activities result. However, a dose-dependent reduction of pendimethalin toxicity was observed when curcumin was supplied with pendimethalin. The maximum recovery of cytological, physiological and oxidative stress parameters was recorded at 10 mg/L concentration of curcumin. The correlation studies also revealed positive relation of curcumin with rooting percentage, root length, weight gain, mitotic activity and glutathione reductase enzyme level while an inverse correlation was observed with chromosomal abnormalities, DNA damage, superoxide dismutase and catalase enzyme activities, and lipid peroxidation indicating its protective effect.
Journal Article
Investigating long-term effect of nanoparticles on growth of Raphanus sativus plants: a trans-generational study
2018
In the past decade, there has been an unprecedented growth in the application of nanoparticles (NPs) worldwide. Even though the acute toxicity of CuO and ZnO NPs to plants has been investigated in past, the trans-generational effects of these NPs in the environment are still unknown. In this study, we investigated whether the treatment of radish plants with CuO and ZnO NPs as single compound and as a binary mixture (10, 100 and 1000 mg/Kg soil) through their lifecycle would affect the seed quality and the development of second-generation seedlings or not. Results showed reduced root length, shoot length and biomass in F1 seedlings of NPs treated plants. The treated F1 seeds had smaller seed weight with accumulated Cu and Zn. The effect of toxic interaction between CuO and ZnO on plant growth was antagonistic in nature. Evaluation of the trans-generational impact is important to understand the long-term effect of NPs on the environment.Graphical abstract[InlineMediaObject not available: see fulltext.]
Journal Article
Examination cheating : risks to the quality and integrity of higher education
2019
We examine the exigencies and impact of examination cheating, focusing specifically on the prevalence and risk of cheating taking place in examination venues. We document the problem with global coverage and note the consistency of the scourge and highlight the different approaches of institutions to dealing with the risk. Stressing the prejudice arising from examination cheating to both universities specifically and society generally, one of the root causes of the risk, namely the moral compass and ethical norms of university students and the societies in which they function, is discussed. The innovation of students when working out cheating practices and the facilitating effects of technology are considered as a backdrop to exemplars of good practices that have been implemented to mitigate the reality and risk of examination fraud. Recognising examination cheating as a fraud on society and a critical risk to university reputation, we question whether university leadership recognises the risk and gives it adequate (and responsible) emphasis in strategic and operational organisational risk identification and management. Significance : Cheating in examinations, and especially in the examination venue, is a global scourge. A comparison of global good practices is presented which provides a framework for institutional discussion to begin to address and transparently deal with the issues and impact of examination cheating. Acknowledging technology as one of the significant enablers of examination fraud and noting the constraints confronting universities, there is nevertheless a critical need for institutions to mitigate the risk. In not doing so, universities, which are fundamentally supported by the fiscus and public taxpayers, are committing a fraud on society. The attitude of some students and academic staff, as well as public perceptions to examination cheating raise the lid on a moral decay that is beginning to manifest in society globally. Universities are challenged to address the issue of examination cheating proactively, openly and honestly. The repercussions of failing to do so are highlighted and exemplars are provided of what can and has already been tried and tested to mitigate the risks.
Journal Article
Seaweed extracts: enhancing plant resilience to biotic and abiotic stresses
by
Nanda, Satyabrata
,
Singh, Sushil Kumar
,
Singh, Divya
in
abiotic stress
,
agricultural productivity
,
biotic stress
2024
Seaweeds are a natural marine resource containing many bioactive compounds such as amino acids, lipids, carbohydrates, proteins, phytohormones, and antimicrobial compounds. Since ancient times, seaweeds have been used in various sectors, including medicine, food, and the cosmetic industry. Currently, seaweeds are a promising alternative to reduce the application of harmful chemicals in agriculture. Seaweed and its derived products have been utilized for plant growth promotion, immunity enhancement, and the reduction of biotic and abiotic stresses. In the current global scenario, synthetic fertilizers and chemical pesticides are commonly used to increase agricultural crop production to meet the growing demands of the world population. However, these chemicals pose significant threats to the health of people, livestock, plants, soil, and the entire environment. In contrast, seaweed-based products are emerging as a newer option for stress mitigation and reduction, offering an alternative to synthetic chemicals. This article explains the use of seaweed extracts to increase the tolerance of plants to biotic and abiotic stresses. We also address the functions of various bioactive compounds present in seaweed extracts and the mechanisms by which they promote plant growth and induce defense against different stresses.
Journal Article
Estrogen Deficiency Induces the Differentiation of IL-17 Secreting Th17 Cells: A New Candidate in the Pathogenesis of Osteoporosis
2012
Th17 cells produce IL-17, and the latter promotes bone loss in collagen-induced arthritis in mice. Blocking IL-17 action in mouse model of rheumatoid arthritis reduces disease symptoms. These observations suggest that Th17 cells may be involved in the pathogenesis of bone loss. However, the role of Th17 cell in estrogen (E2) deficiency-induced bone loss is still not very clear. We investigated the effect of E2 on Th17 differentiation in vivo and IL-17 mediated regulation of osteoclast and osteoblast differentiation. Additionally, effect of IL-17 functional block under E2 deficiency-induced bone loss was studied. In murine bone marrow cells, E2 suppressed IL-17 mediated osteoclast differentiation. IL-17 inhibited formation of mineralized nodules in osteoblasts and this effect was suppressed by E2. E2 treatment to mouse calvarial osteoblasts inhibited the IL-17-induced production of osteoclastogenic cytokines and NF-kB translocation. In ovariectomized mice, there was increase in the number of Th17 cells, transcription factors promoting Th17 cell differentiation and circulating IL-17 levels. These effects were reversed by E2 supplementation. Treatment of neutralizing IL-17 monoclonal antibody to Ovx mice mitigated the E2 deficiency-induced trabecular bone loss and reversed the decreased osteoprotegerin-to-receptor activator of nuclear factor kappa B ligand (RANKL) transcript levels in long bones, increased osteoclast differentiation from the bone marrow precursor cells and decreased osteoblast differentiation from the bone marrow stromal cells. Our findings indicate that E2 deficiency leads to increased differentiation of Th17 cells with attendant up regulation of STAT3, ROR-γt and ROR-α and downregulation of Foxp3 which antagonizes Th17 cell differentiation. Increased IL-17 production in turn induces bone loss by increasing pro-osteoclastogenic cytokines including TNF-α, IL-6 and RANKL from osteoblasts and functional block of IL-17 prevents bone loss. IL-17 thus plays a critical causal role in Ovx-induced bone loss and may be considered a potential therapeutic target in pathogenesis of post menopausal osteoporosis.
Journal Article