Browsing by Author "Santosh Kumar Prajapati"

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Assessing the genotoxicity of urban air pollutants in Varanasi City using Tradescantia micronucleus (Trad-MCN) bioassay
(Elsevier Ltd, 2008) Santosh Kumar Prajapati; B.D. Tripathi
In the present study Tradescantia micronucleus (Trad-MCN) bioassay was performed to assess the genotoxicity of air pollutants in Varanasi City. The experiment was performed during October 2006 to April 2007. For Tradescantia micronucleus (Trad-MCN) bioassay four sites were selected, three in the city having different traffic characteristics and one control site virtually free from traffic intervention. Twenty young Tradescantia pallida inflorescences were collected from each sampling site during the study period and micronuclei frequencies were determined in early tetrads of pollen mother cells and expressed as MCN/100 tetrads. During the same period the concentration of different air pollutants were also measured. Tradescantia micronucleus (Trad-MCN) bioassay showed that the plants kept in areas having higher traffic emissions evidence higher micronuclei frequencies than samples kept at control site. The study indicates that in situ biomonitoring using higher plants may be useful for characterizing genotoxic air pollutants in areas even without any sophisticated instrument. © 2008 Elsevier Ltd. All rights reserved.
Biomonitoring seasonal variation of urban air polycyclic aromatic hydrocarbons (PAHs) using Ficus benghalensis leaves
(2008) Santosh Kumar Prajapati; B.D. Tripathi
Temporal and seasonal variations of polycyclic aromatic hydrocarbons (PAHs) concentrations in leaves of Ficus benghalensis were investigated in Varanasi city (India). Leaf samples were collected from six sites from urban area of Varanasi and from a control site. PAH extraction was done by sonication in dichloromethane-acetone and quantification by GC-MS. In January total leaf PAHs concentrations at all the urban sites were twice higher as compared to other season's viz. summer and rainy. In contrast, at the control site leaf PAHs concentrations showed lower values than urban sites. The maximum concentrations of total PAHs in winter were due to the medium molecular weight PAHs which increases with respect to both low and high molecular weight PAHs. The temporal variation of medium molecular weight PAHs was similar both at the urban and remote sites. These results support biomonitoring ability of Ficus benghalensis leaves to temporal variations in PAHs contamination. © 2007 Elsevier Ltd. All rights reserved.
Centella asiatica prevents D-galactose-Induced cognitive deficits, oxidative stress and neurodegeneration in the adult rat brain
(Taylor and Francis Ltd., 2022) Zeba Firdaus; Neha Singh; Santosh Kumar Prajapati; Sairam Krishnamurthy; Tryambak Deo Singh
Chronic D-galactose (D-gal) administration causes cognitive impairment and is used widely in animal models for anti-aging studies. Centella asiatica (CA), a traditional herbal medicine, has been used as a brain tonic to enhance memory. This study evaluates the neuroprotective role of an ethanolic extract of Centella asiatica (CAE) against D-gal-induced aging in rats. Healthy male rats were divided into three groups: Control, D-gal, and D-gal + CAE. The Control group received normal saline (i.p.), whereas the D-gal group received D-gal (120 mg/kg b.w., i.p.), and the D-gal + CAE group received D-gal (120 mg/kg b.w., i.p.) and CAE (300 mg/kg b.w., orally) daily for 42 days. Behavioral and brain biochemical and histopathological changes were assessed after treatment. The results of the behavioral study depicted that D-gal significantly reduces the spontaneous alternation and locomotor activity indicating behavioral and cognitive impairment. Biochemical studies showed that D-gal significantly increases the oxidative stress and acetylcholinesterase activity (AChE) in rat brain. Histopathological study showed that D-gal disturbs the normal architecture of hippocampal and cortical cells, indicating degeneration in these brain areas. D-gal and CAE co-treatment for 42 days attenuated the behavioral, biochemical, and neuroanatomical impairments caused by the D-gal; it markedly suppresses the D-gal-induced oxidative stress and AChE activity in the brain, and maintains the normal cellular architecture in hippocampal and cortical areas. Thus, this study shows that CAE can protect the brain from the adverse effects of D-gal (e.g., memory loss and cognitive impairment) by modulating AChE activity and oxidative stress. © 2020 Informa UK Limited, trading as Taylor & Francis Group.
Effects of extremely low-frequency (50 Hz) electromagnetic fields on vital organs of adult Wistar rats and viability of mouse fibroblast cells
(Oxford University Press, 2025) Chandra Kant Singh Tekam; Shreyasi Majumdar; Pooja Kumari; Santosh Kumar Prajapati; Ajay Kumar Sahi; Richa S. Singh; Sairam Krishnamurthy; Sanjeev Kumar Mahto
In recent years, scientific communities have been concerned about the potential health effects of periodic electromagnetic field exposure (≤1 h/d). The objective of our study is to determine the impact of extremely low-frequency pulsed electromagnetic fields (ELF-PEMF) (1-3 mT, 50 Hz) on mouse fibroblast (red fluorescent protein (RFP)-L929) cells and adult Wistar rats to gain a comprehensive understanding of biological effects. We observed that RFP-L929 exhibits no significant changes in cell proliferation and morphology but mild elevation in aspartate aminotransferases, alanine aminotransferases, total bilirubin, serum creatinine, and creatine kinase-myocardial band levels in ELF-PEMF exposed groups under in vitro and in vivo conditions. However, the histological examination showed no significant alterations in tissue structure and morphologies. Our result suggests that 50-Hz ELF-PEMF exposure (1-3 mT, 50 Hz) with duration (<1 h/d) can trigger mild changes in biochemical parameters, but it is insufficient to induce any pathological alterations. © 2024 The Author(s). Published by Oxford University Press. All rights reserved.
Magnetic properties of vehicle-derived particulates and amelioration by Ficus infectoria: A keystone species
(Royal Swedish Academy of Sciences, 2005) Sudhir Kumar Pandey; B.D. Tripathi; Santosh Kumar Prajapati; Virendra Kumar Mishra; Alka Rani Upadhyaya; Prabhat Kumar Rai; Atul Prakash Sharma
[No abstract available]
Management of hazardous road derived respirable particulates using magnetic properties of tree leaves
(2008) Santosh Kumar Prajapati; B.D. Tripathi
The magnetic properties of tree leaves along with their ecological, economical and aesthetic importance can be used to control road derived respirable particulates. Isothermal remanent magnetization (IRM300 mT) of three different tree leaves viz. Mango (Mangifera indica), Sisso (Dalbergia sisso) and Banyan (Ficus benghalensis) were determined and IRM300 mT normalized for the leaf area. The normalized 2-D magnetization of leaves as shown by results is dominantly controlled by leaf morphology and traffic density. F. benghalensis (Banyan) leaf has highest 2-D magnetization and D. sisso (Sisso) leaf having least 2-D magnetization suggesting greater ability of F. benghalensis (Banyan) tree leaves to reduce magnetic particulates. The particle size of the magnetic grains falls in the category of PM2.5, a particle size hazardous to human health due to its capacity to be inhaled deeply into the lungs. © Springer Science+Business Media B.V. 2007.
Monitoring of vehicles derived particulates using magnetic properties of leaves
(2006) Santosh Kumar Prajapati; Sudhir Kumar Pandey; B.D. Tripathi
Biomonitoring of vehicle-derived particulates is conducted by taking magnetic measurements of roadside tree leaves. Remanent magnetization (IRM300mT) of more than 400 Delbergia sissoo leaves was determined and IRM300mT normalized for the leaf area. The normalized 2-D magnetization as shown by results is dominantly controlled by the tree's distance to the road. The spatial and temporal variations of vehicle-derived particulates were mapped using magnetic analysis. 2D-magnetizations values were higher for leaves collected adjacent to major road sections than for those from village road suggesting vehicle emissions, rather than resuspended road dust, as the major cause of magnetic particles of roadside tree leaves. Vehicles derived particulates are responsible for tree leaf magnetism, and the leaf magnetizations values fall significantly from high values proximal to the roadside to lower values at the distal side. This suggests the ability of trees to reduce particulates concentrations in the atmosphere. The rainfall produces a net decrease in the leaf magnetic dust loadings. © Springer Science+Business Media, Inc. 2006.
Neurochemical, Neurocircuitry, and Psychopathological Mechanisms of PTSD: Emerging Pharmacotherapies and Clinical Perspectives
(American Chemical Society, 2025) Santosh Kumar Prajapati; Shreyasi Majumdar; Snehapriya Murari; Kirti MachhindraVadak; Sairam Krishnamurthy
Post-traumatic stress disorder (PTSD) is a debilitating psychiatric condition triggered by exposure to traumatic events, with complex neurobiological anomalies that remain incompletely understood. This review aims to comprehensively explore the neurocircuitry, neurochemical dysregulation, and emerging pharmacological targets associated with PTSD, offering a consolidated framework for developing more effective treatments. Particular emphasis is employed on the role of the hypothalamic-pituitary-adrenal (HPA) axis, monoamines, glutamate, GABAergic, and the orexinergic system, as well as emerging therapeutic agents such as 3,4-methylenedioxymethamphetamine (MDMA), ketamine, suvorexant, and cannabinoid modulators. Psychotherapeutic approaches including cognitive-behavioral therapy (CBT) and prolonged exposure therapy are also discussed in the context of their neurobiological effects. Articles were identified through a structured search in PubMed, Scopus, and Google Scholar, focusing on English-language publications from 1950 to 2025. Inclusion criteria encompassed original research, clinical trials, and reviews relevant to PTSD mechanisms and treatment. By integrating recent findings, this review advances the understanding of PTSD pathophysiology and highlights potential avenues for targeted, personalized therapies, thereby contributing to clinical and translational research in neuropsychiatry. © 2025 American Chemical Society.
Seasonal variation of leaf dust accumulation and pigment content in plant species exposed to urban particulates pollution
(2008) Santosh Kumar Prajapati; B.D. Tripathi
To assess the dust interception efficiency of some selected tree species and impact of dust deposition on chlorophyll and ascorbic acid content of leaves the present study was undertaken. The plant species selected for the study were Ficus religiosa, Ficus benghalensis, Mangifera indica, Dalbergia sissoo, Psidium guajava, and Dendrocalamus strictus. It was found that all species have maximum dust deposition in the winter season followed by summer and rainy seasons. Chlorophyll content decreased and ascorbic acid content increased with the increase of dust deposition. There was significant negative and positive correlation between dust deposition and chlorophyll and ascorbic acid content, respectively. Maximum dust interception was done by Dalbergia sisso and least by Dendrocalamus strictus. Thus plants can be used to intercept dust particles which are of potential health hazards to humans. Copyright © 2008 by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America. All rights reserved.
Suvorexant improves mitochondrial dynamics with the regulation of orexinergic and mTOR activation in rats exhibiting PTSD-like symptoms
(Elsevier B.V., 2024) Santosh Kumar Prajapati; Sahabuddin Ahmed; Vipin Rai; Subhas Chandra Gupta; Sairam Krishnamurthy
Background: Increasing evidence suggests that mitochondrial dysfunction plays a significant role in PTSD. However, the exact mechanism is still unclear. Mitochondrial dynamics could be one of the mechanisms, as it is crucial for mitochondrial homeostasis and is widely affected in traumatic situations. Mitochondrial dynamics regulate mitochondrial homeostasis via orexinergic receptors, and it is shown that antagonism of orexinergic receptors attenuates PTSD-like symptoms. Therefore, the present study aimed to determine how orexin antagonists affect mitochondrial dynamics in rats exhibiting PTSD-like symptoms. Methods: Using rats, a stress-re-stress (SRS) model with PTSD-like symptoms was established. On day 2 (D-2), the animals were exposed to variable stressors including 2 h of restraint followed by brief mild foot shock and exposure to 4%halothane. Foot shock was performed as a re-stress from D-8 to D-32 at six-day intervals. Results: SRS exposure caused PTSD-like phenotype, hypothalamic-pituitary-adrenal axis dysfunction, activation of mammalian target of rapamycin (mTOR), and mitochondrial-fission-process-1 (MTFP-1). SRS-subjected rats exhibited enhanced expression of fission-regulating proteins, including dynamin-related protein-1 and mitochondrial-fission-protein-1 and reduced expression of fusion-regulating proteins, including optic-atrophy-1 and mitofusin-2, in the amygdala. TEM analysis revealed that SRS exposure further damaged the mitochondria. Treatment with suvorexant with rapamycin significantly mitigated PTSD-like symptoms and improved mitochondrial dynamics in SRS-exposed rats. However, their combination showed a more pronounced effect. Further, suvorexant in combination with rapamycin significantly mitigated mTOR and MTFP-1 activation. Sertraline attenuated PTSD-like symptoms without affecting SRS-induced activation of mTOR and disparity in mitochondrial dynamics. Suvorexant pharmacological effects on mitochondrial biogenesis also involve the mTOR pathway. Limitation: The role of orexinergic pathway in SRS-induced mitochondrial mitophagy was not explored. Conclusions: Targeting both the orexinergic and mTOR pathways might exert a beneficial synergistic effect for treating PTSD. © 2024 Elsevier B.V.