Browsing by Author "Amaresh Kumar Singh"

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Age dependent nitro-oxidative load and melatonin receptor expression in the spleen and immunity of goat Capra hircus
(Elsevier Inc., 2014) Amaresh Kumar Singh; Chandana Haldar
The decline in the plasma level of melatonin has been associated with increased oxidative stress in the physiological system while aging. The increased levels of oxidants are known to augment the nitro-oxidative stress, which induces the apoptotic factors in lymphoid organs leading to age dependent immunosenescence. There are no reports to date that can suggest how the age dependent nitro-oxidative stress can influence the melatonin membrane MT1/MT2R expression and immune status of any small ruminant. In the present study, we noted the expression of melatonin receptors MT1R and MT2R and inducible nitric oxide synthase (iNOS) along with the apoptotic markers (viz. Bcl-2, Bax and Pro-caspase-3) in the spleen of young, middle-aged and old-aged Indian goat Capra hircus. The lymphocyte proliferation was also recorded along with the total nitrite and nitrate ion concentration (NOx) in the spleen and plasma. An age dependent decline in MT1R and MT2R expressions and lymphocyte proliferation with increased level of reactive nitrogen species (RNS) and iNOS expression was noted. An increased Bax/Bcl-2 ratio and a decreased Pro-caspase-3 expression were observed in the spleen of goat with an age dependent decline in the peripheral melatonin level. This decline in melatonin along with reduced melatonin receptor (MT1/MT2) expression and elevated RNS level in the spleen with aging might have an important role in the regulation of immune function of goats. Our observations suggest that the age-associated immunosenescence observed in goats can be a consequence of declining melatonin and its receptor expression and induction of apoptotic factors influenced by the increased RNS level that deteriorates the proper functioning of the spleen. © 2014 .
Characterization and potential novel applications of zinc-based traditional medicine, Yashad Bhasma
(Elsevier B.V., 2025) Guruprasad C. Nille; Monisha Bhuyan; Laxmi Narayan Gupta; Mohd Ali; Chandra Shekhar Pati Tripathi; Omkar S. Nille; Shardendu K. Mishra; Anuja A. Vibhute; Pranoti Anil Kamble; Himanshu Ranjan; Amaresh Kumar Singh; Arpita P-Tiwari; Anand Kumar Chaudhary
Background: Yashad Bhasma (YB), the incinerated metal ash of zinc, has been used for centuries in Ayurveda to address a variety of conditions, including eye diseases, diabetes mellitus, anemia, respiratory illnesses, etc. Objective: This research aimed to synthesize and characterize YB and to evaluate its potential antimicrobial, antioxidant, and anti-angiogenic activities. Materials and methods: In this study, YB is synthesized by optimizing the traditional method. Morphological and physicochemical characterization are performed using XRD, XPS, SEM, TEM, EDAX, DLS, TGA-DSC, and FTIR. The antimicrobial activity of YB is assessed using the well diffusion technique against the gram-positive bacterium Staphylococcus aureus (S. aureus) and the gram-negative bacterium Escherichia coli (E. coli). The antioxidant potential is evaluated using the 1,1-Diphenyl-2-Picrylhydrazyl (DPPH) radical scavenging assay and Nitric oxide (NO) radical scavenging assay. A chick chorioallantoic membrane (CAM) assay is performed on fertilized chick eggs to study the anti-angiogenesis potential of YB. Results: The XRD patterns of YB showed the presence of cubic and hexagonal phases of ZnS having average crystallite size of 32.66 nm. XPS data supports the formation of ZnS phase of YB. SEM and TEM data confirmed the size of YB NPs in a range of 250–350 nm. The EDAX analysis confirmed the presence of Zn (37.2 %) and S (21.18 %). The mean particle diameter was 361 nm in DLS. TGA-DSC findings verified that the synthesized material is stable up to 435.80 °C. The FTIR confirms the presence of organic moieties in YB along with ZnS phase. YB effectively inhibited the growth of S. aureus and E. coli. The ability of YB to scavenge DPPH and NO radicals is found to be concentration dependent (50–250 μg/mL). The study also demonstrated that YB has notable antioxidant activity. The disappearance of blood vessels beneath the sample-loaded disk after 7 days indicated the effective anti-angiogenic properties of YB. Conclusion: Altogether, YB exhibited significant antimicrobial, noteworthy antioxidant, and anti-angiogenic activities, indicating its potential as a promising therapeutic agent. © 2025 The Authors
Daily variation in melatonin level, antioxidant activity and general immune response of peripheral blood mononuclear cells and lymphoid tissues of Indian goat Capra hircus during summer and winter
(National Institute of Science Communication, 2014) Amaresh Kumar Singh; Somenath Ghosh; Priyoneel Basu; Chandana Haldar
Daily variation in circulatory melatonin level, during different seasons, has been reported to influence immune system and free-radical scavenging capacity in mammals, including human beings. Similar studies have not been carried out on small ruminant viz. goats that are susceptible to opportunistic infections, increased oxidative load and sickness during freegrazing activity and frequent exposure to agro-chemicals. Therefore, daily variation in immune status, antioxidant enzyme activity and its possible correlation with circulatory melatonin level during two different seasons, summer (long day) and winter (short day) were studied in the Indian goat, Capra hircus. The clinically important immune parameters, such as total leukocyte count, % lymphocyte count and % stimulation ratio of T-lymphocytes presented a day/night rhythm prominently in the winter. The oxidative load in terms of malonedialdehyde was always low during night while antioxidant enzymes superoxide dismutase, catalase and total antioxidant status were high during nighttime (1800 to 0600 hrs). Interestingly, the studied parameters were significantly higher during the winter in both the sexes. Rhythmometric analyses showed prominent rhythmicity in above parameters. The data presented strong positive correlation between high levels of nighttime melatonin levels and immune parameters during winter. It suggests that melatonin possesses immunoenhacing as well as antioxidative property during winter. This might be a necessity for maintenance of physiological harmony in goats to protect them from winter stress.
Dual metal ion (Fe3+ and As3+) sensing and cell bioimaging using fluorescent carbon quantum dots synthesised from Cynodon dactylon
(Elsevier Ltd, 2023) Sweta Gurung; Neha; Nimmala Arun; Mayank Joshi; Tanya Jaiswal; Anand P. Pathak; Parimal Das; Amaresh Kumar Singh; Ajay Tripathi; Archana Tiwari
In this study, water dispersible fluorescent carbon quantum dot (CQD) has been synthesised, having an average size of 8.6 ± 0.4 nm using Cynodon dactylon (CD) following microwave assisted green synthetic one-step method. As-prepared CQD fluoresces strongly at 444 nm having a quantum yield of 1% in water when excited at 350 nm. This fluorescence of CQD is sensitive toward As3+ and Fe3+ metal ions. These CQD are utilized for dual metal ion fluorescence sensing; turn-on fluorescence sensing for As3+ and turn-off fluorescence sensing for Fe3+ ions. Limit of detection for As3+ and Fe3+ ions has been found to be 19 nM and 0.10 μM respectively, which is the lowest value reported for As3+ without any functionalization. The adsorption kinetics of As3+ and Fe3+ ions on CQD have been examined using pseudo-first-order-kinetic model revealing that physical adsorption is dominant over chemical processes in this work. For 0.41 g/L and 1.90 g/L dose of CQD, the equilibrium adsorption capacity was found to be 1.57 × 10−6 mg/g, 2.91 × 10−7 mg/g, and 1.01 × 10−5 mg/g, 1.69 × 10−6 mg/g respectively for As3+ and Fe3+ ions. Despite having low quantum yield in water, as-prepared CQD showed low cytotoxicity and good tolerance against photodegradation of biological cells at concentrations lower than 62.5 μg/mL and when the cells are illuminated up to 12 h. Owing to this, the synthesised CQD have been utilized as fluorescent probes for in itro cell imaging. © 2023 Elsevier Ltd
Effect of Stress-WIN, a novel polyherbal formulation, on DOCA-salt-induced hypertensive Wistar rats
(Springer Nature, 2025) Amit Ranjan; Anirban Roy; Poonam Pal; Somesh Agarwal; Amaresh Kumar Singh; Vinod N. Tiwari; Shreyans Kumar Jain; Hitesh Harsukhbhai Chandpa; Ankita Yadav; Sanjeev Kumar
Hypertension is a multifactorial disorder and one of the most important risk factors and a leading cause of stroke, heart disease, and end-organ damage. Hypertension leads to the production of high levels of pro-inflammatory cytokines and cholesterol, which increase thrombogenesis and fibrosis, ultimately resulting in chronic inflammation. Chronic inflammation causes endothelial dysfunction by producing excess reactive oxygen species (ROS) through pro-inflammatory cytokines such as interleukine-1β (IL-1β) and tumor necrosis factor-α (TNF-α). Further, the high level of nitric oxide (NO) and malonaldehyde (MDA) increases the oxidative stress, which worsens the liver's production of SGOT and SGPT and glomerular filtration of the kidney. In this study, an Ayurvedic polyherbal formulation (StressWIN) was shown to be a potent therapeutic drug for the treatment of deoxycorticosterone (DOCA)-salt-induced hypertension in Wistar rats. This study showed that administration of Stress-WIN significantly reduced the expression of pro-inflammatory cytokines (IL-1β and TNF-α) and also reduced the level of ROS, NO, MDA, SGOT, and SGPT in the serum of DOCA-salt-induced hypertension in Wistar rats. Furthermore, Stress-WIN treatment exhibited reduced cholesterol levels and glutathione concentration. Histological analysis showed that infiltration of immune cells was reversed by Stress-WIN A treatment (500 mg/kg and 1000 mg/kg). Furthermore, Stress-WIN A (2000 mg/kg) administration attenuated DOCA-salt-mediated morphological changes in the kidney and the heart of the Wistar rat. These promising outcomes underscore the potential of Stress-WIN as a viable alternative or adjunct therapy for hypertension, warranting further clinical investigations. © The Author(s) 2025.
In vivo safety assessment of a polyherbal formulation (Stress WIN) proposed for clinical hypertension management
(Springer Nature, 2024) Somesh Agarwal; Anirban Roy; Vinod Tiwari; Poonam Pal; A. Kartika; Rajesh Sharma; Amaresh Kumar Singh; Sanjeev Kumar
Herbal treatments are nowadays considered dietary supplements and nutraceuticals for health maintenance and alternative/complementary therapy. A large range of herbal medications worldwide can easily be accessible in the local market. The polyherbal formulation (Stress WIN) containing Ashwagandha (Withania somnifera L. Dunal), Pushkarmoola (Inula racemosa Hook. F.), and Jatamansi (Nardostachys jatamansi (D. Don) DC.) root has been used empirically in the management of hypertension. However, toxicity data for the StressWIN is not available yet. The present study aims to evaluate the StressWIN’s safety profile by 28 days of repeated dose oral toxicity in Wistar rats. Rats received different doses (500 mg/kg/day, 1000 mg/kg/day, and 2000 mg/kg/day) of StressWIN, for 28 days. The study was conducted in compliance with the OECD guideline 423. No significant differences were observed in hematological and biochemical parameters as compared to the control group (p > 0.05). Histopathological studies revealed no significant alterations in the macroscopic and microscopic architecture of the liver, kidney, heart, and spleen of the StressWIN treated groups in comparison to the control group (p > 0.05). Findings from the present study suggest that StressWIN supplementation has not shown any side effects in terms of sub-acute toxicity in both male and female rats. These findings indicated no observed adverse effect level (NOAEL) of StressWIN was higher than 2000 mg/kg/day. © The Author(s) 2024.
Melatonin modulates glucocorticoid receptor mediated inhibition of antioxidant response and apoptosis in peripheral blood mononuclear cells
(Elsevier Ireland Ltd, 2016) Amaresh Kumar Singh; Chandana Haldar
Pineal melatonin is known for its immunomodulatory and anti-stress properties. It modulates stress condition by regulating antioxidant responses and apoptosis in the immune cells. Stress causes increased glucocorticoid level that acts through glucocorticoid receptor (GR) and is translocated into nucleus under regulation of HSP90 based chaperone machinery. Melatonin influences glucocorticoid and GR mediated stress condition in rodents, but till date there are no reports which could suggest the effect of melatonin treatment on GR mediated apoptosis and inhibition of Nrf-2/hemeoxygenase-1 (HO-1) induced antioxidant status in immunocompetent cells (peripheral blood mononuclear cells; PBMCs). Therefore, in the present study, we considered GR mediated inhibition of Nrf2 and HO-1 along with anti-apoptotic Bcl-2 expression in PBMCs. The PBMCs were treated with synthetic glucocorticoid; dexamethasone (Dex) and melatonin (Mel), to explore the effect of melatonin treatment in regulation of GR mediated apoptosis and inhibition of antioxidant status in immune cells. It was noted that melatonin treatment retained GR into cytoplasm by inhibiting the dissociation of HSP90 from GR-HSP90 complex and enhanced expression of Nrf2/HO-1 and Bcl-2 expression. This led to increased HO-1 expression and elevated Bcl-2 led to increased Bcl-2/Bax ratio that might ultimately enhanced the cellular antioxidant response and survival under glucocorticoid mediated stress condition. Our observations suggest that the declined GR nuclear translocation upon melatonin treatment might be responsible for the up-regulation of Nrf2 mediated HO-1 activity and increased Bcl-2/Bax ratio in PBMCs to maintain the immune homeostasis under stress condition. © 2016
Oviduct contractility in non-pregnant rats: changes in estrous cycle and effects of estrogen and progesterone antagonists
(BioScientifica Ltd., 2025) Richa S. Singh; Parul Sharma; Shristi Modanwal; Himanshu Ranjan; Amaresh Kumar Singh; Sakshi Agarwal; Sanjeev Kumar Mahto
This study aimed to systematically characterize oviduct contractility across the estrous cycle and to examine the regulatory roles of estradiol and progesterone using receptor antagonists and molecular docking to explore both receptor-mediated and ion channel pathways. Female Wistar rats (n = 48) were used for this purpose. Oviducts were collected during proestrus, estrus, metestrus, and diestrus, and spontaneous contractions were recorded using an isometric force transducer. Serum levels of estradiol, progesterone, luteinizing hormone, follicle-stimulating hormone, and prolactin were measured through enzyme-linked immunosorbent assay (ELISA). To understand hormonal regulation, tamoxifen (10 mg/kg) was administered during proestrus, and mifepristone (5 mg/kg) was administered during metestrus. Immunofluorescence (IF) study was performed to evaluate expression of the estrogen, progesterone, and glucocorticoid receptors (ER, PR, and GR). Molecular docking analysis assessed interactions of the antagonists with estrogen and progesterone receptors and ion channels. Oviduct contractility was observed noticeably highest during proestrus (high estradiol) and lowest in metestrus and diestrus phases (high progesterone). Tamoxifen significantly reduced contraction parameters (P < 0.001) and estradiol levels, while mifepristone notably increased contraction force (P < 0.01), elevated estradiol levels (P < 0.001), and decreased the proportion of progesterone hormone. The IF study indicated suppression of ER, PR, and GR expression following treatment with mifepristone. Docking analysis revealed that tamoxifen interacted with potassium channels and ERβ, while mifepristone showed high affinity for PR, GR, and calcium channels. These findings highlight that oviduct contractility is dynamically regulated across the estrous cycle through both receptor-mediated and potential non-receptor and non-genomic pathways involving ion channels. © 2025 the author(s)
Phyto-Melatonin: A Novel Therapeutic Aspect of Melatonin in Nature’s Way
(CRC Press, 2014) Chandana Haldar; Somenath Ghosh; Amaresh Kumar Singh
Around nineteenth century, some preliminary studies indicated that plants may possess melatonin (Mel; Kolár et al., 1995), but clear-cut indications that the plants are having Mel were supported by scientists later during 1995 (Dubbels et al., 1995). However, the existence of phyto-melatonin was reported by scientists in micro-and macro-alga (Balzer et al., 1998), particularly in red alga (Rhodophyta, Lorenz and Lüning, 1998), metazoans (Hardeland, 1999), and other photoautotrophic microorganisms (Hardeland and Poeggeler, 2003). Among the other plant groups, the existence of Mel is still controversial and needs further proof. Phyto-melatonin is now accepted to be present only in angiosperms, in their different parts like fruits, seeds, etc., including some medicinal herbs (Reiter et al., 2007). The reason behind this fact is mainly the lack of specic molecular and biochemical approaches to detect the same in plants other than angiosperms. © 2015 by Taylor & Francis Group, LLC.