Browsing by Author "Shraddha Rastogi"

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Comparative effect of melatonin and quercetin in counteracting LPS induced oxidative stress in bone marrow mononuclear cells and spleen of Funambulus pennanti
(Elsevier Ltd, 2018) Shraddha Rastogi; Chandana Haldar
A majority of cellular diseases, independent of their origin, are characterized by a dramatic increase in Reactive Oxygen Species (ROS) in response to stress. In most cases, the uncontrolled detrimental ROS outburst is difficult to handle for the cellular machinery and eventually leads to cell mortality. In this study, we compare the antioxidant efficacy of quercetin and melatonin to find out a better alternative against lipopolysaccharide (LPS) induced tissue injury by oxidative stress in Funambulus pennanti. Transient exposure to LPS significantly increased ROS generation and lipid peroxidation levels in bone marrow mononuclear cells (MNCs) and spleen which was further corroborated by decreased activities of SOD, CAT and Gpx enzymes. It also downregulate the expression of cellular oxidative stress response proteins Nrf-2 and HO-1 in spleen and decreases the proliferation of bone marrow derived Granulocyte macrophage-colony forming unit cells (GM-CFU). Both melatonin and quercetin pre-treatments rescued these effects, however, our results indicated that the efficacy of melatonin to overcome oxidative stress was significantly better than quercetin. Our findings support the idea that melatonin is a better antioxidant and immunomodulator as compared to other alternatives and perhaps may be employed in the development of effective therapeutics against ROS dominated diseases. © 2018
Erratum: “Role of melatonin and HSF-1\HSP-70 in modulating cold stress-induced immunosuppression in a tropical rodent- Funambulus pennanti” (Journal of Thermal Biology (2020) 87, (102456), (S0306456519300889), (10.1016/j.jtherbio.2019.102456))
(Elsevier Ltd, 2021) Shraddha Rastogi; Chandana Haldar
The neuroendocrine hormone melatonin and molecular chaperones (heat shock proteins) are evolutionarily conserved molecules that play an important role in protecting organisms from abiotic and biotic stressors. Environmental temperature and seasonality modulates immunity which impacts the overall health of animals. Most studies in relation to thermal stress are based on animals inhabiting temperate zones however, the substantial effect of climatic stress on tropical animals is less explored. Therefore, in this study we focused on the immunosuppressive effect of cold environment on a seasonally breeding tropical rodent and highlighted the importance of melatonin and HSF-1/Hsp-70 in regulating immunity. Animals were exposed to different temperatures with or without melatonin treatment. Our results suggest that, low temperature elicited cold-associated stress in animals marked by reduced body weight, decreased TLC/LC count in the blood and increased corticosterone production which was central to all immune alterations. Cold temperature also increased the oxidative stress which further induced apoptosis in the immune cells and activated stress response molecular chaperones HSF-1/HSP-70. Exogenous melatonin treatment not only ameliorated cold-induced immune suppression but also upregulated the expression of HSF-1 and HSP-70 in the immune cells thereby preventing protein unfolding and cell death. Thus, we conclude that melatonin and molecular chaperones synergistically alleviated immune suppression and could emerge as a promising combination therapy to target temperature stress in animals while boosting immunity. © 2021 Elsevier Ltd
Nephroprotective effect of melatonin and L-Ascorbic acid (Vitamin-C) against ampicillin- induced toxicity in Funambulus pennanti
(Taylor and Francis Ltd., 2020) Shraddha Rastogi; Sameer Gupta; Chandana Haldar; Dinesh Chandra
Ampicillin is one of the most commonly prescribed antibiotics against intra-renal infections. Prolonged use of ampicillin has been found to be associated with a high rate of free-radical generation and oxidative stress induced nephrotoxicity. In the present study, we report the comparative effects of melatonin and vitamin-C (Vit-C) in ameliorating the biochemical and structural alterations in renal tissues caused by ampicillin sodium. Biochemical parameters such as acid phosphatase (ACP), alkaline phosphatase (ALP), creatinine and urea levels in urine and serum as well as oxidative stress parameters such as superoxide dismutase (SOD) activity, catalase activity, total antioxidant status (TAS%) and lipid peroxidation in the renal cortical tissues were accessed upon treatment of melatonin and Vit-C following ampicillin sodium administration in Funambulus pennanti. Ampicillin treatment increased ACP, ALP, creatinine and urea levels in serum and urine, indicating renal damage. It also induced oxidative stress by increasing lipid peroxidation and decreasing the activity of antioxidative enzymes. However, the exogenous melatonin or Vit-C treatment inhibited ampicillin mediated renal damages. Melatonin or Vit-C pre-treatment significantly decreased ACP, ALP, creatinine, urea, TBARS level and increased SOD, catalase activity and TAS%. Our results suggest that the antibiotic induced nephrotoxicity can be ameliorated by melatonin or Vit-C via reduction of oxidative stress in renal tissues. © 2020 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.
Role of melatonin and HSF-1\HSP-70 in modulating cold stress-induced immunosuppression in a tropical rodent- Funambulus pennanti
(Elsevier Ltd, 2020) Shraddha Rastogi; Chandana Haldar
[No abstract available]
Seasonal plasticity in immunocompetent cytokines (IL-2, IL-6, and TNF-α), myeloid progenitor cell (CFU-GM) proliferation, and LPS-induced oxido-inflammatory aberrations in a tropical rodent Funambulus pennanti: role of melatonin
(Springer Science and Business Media B.V., 2023) Shraddha Rastogi; Chandana Haldar
In seasonal breeders, photoperiods regulate the levels of circulatory melatonin, a well-known immunomodulator and an antioxidant. Melatonin is known to play a complex physiological role in maintaining the immune homeostasis by affecting cytokine production in immunocompetent cells. In this study, we have quantified seasonal and temporal variations in immunocompetent cytokines—IL-2, IL-6, and TNF-α—and circulatory corticosterone along with in- vitro proliferation of bone marrow-derived granulocyte macrophage-colony forming unit (CFU-GM) progenitor cells of a tropical seasonal breeder Funambulus pennanti (northern palm squirrel). Transient variations in antioxidant status of seasonal breeders might be due to the fluctuations associated with immunity and inflammation. Further, to establish a direct immunomodulatory effect of photoperiod, we recorded the LPS-induced oxidative and inflammatory responses of squirrels by housing them in artificial photoperiodic chambers mimicking summer and winter seasons respectively. We observed a marked variation in cytokines level, melatonin, and corticosterone , and CFU-GM cell proliferation during summer and winter seasons. High Peripheral melatonin levels directly correlated with cytokine IL-2 levels, and inversely correlated with TNF-α, and circulatory corticosterone level. LPS-challenged squirrels housed in short photoperiod (10L:14D; equivalent to winter days) showed a marked reduction in the components of the inflammatory cascade, CRP, TNF-α, IL-6, NOx, NF-κB, Cox-2, and PGES, with an overall improvement in antioxidant status when compared to squirrels maintained under a long photoperiod (16L:8D; equivalent to summer days). Our results underline the impact of seasonality, photoperiod, and melatonin in maintaining an intrinsic redox-immune homeostasis which helps the animal to withstand environmental stresses. © 2022, The Author(s), under exclusive licence to Cell Stress Society International.
Therapeutic aspects of melatonin in bone marrow and thyroid associated immune regulation
(Nova Science Publishers, Inc., 2017) Shraddha Rastogi; Rakesh Verma; Chandana Haldar
The immune system is functionally compartmentalized and is collectively modulated by various internal factors such as hormones, cytokines and externally by seasonal variations in day-length. Neuro-hormone melatonin serves as a "Timezyme" (marker of day-length variation) and a connecting link between the neuro-immuno-endocrine circuits. The role of melatonin in regulating immune functions is well documented. Previous studies have reported that the process of hematopoiesis is regulated by the peripheral levels of melatonin as well as the melatonin synthesized within the microenvironment of bone marrow. The bone marrow granulocyte macrophage colony forming cells (CFU-GM) rhythmically proliferates during the dark hours coinciding with the higher circulatory levels of melatonin. Melatonin acts through its highly specific receptor MT1 present on the surface of progenitor immuno-competent cells (B- and T-cells). Literature suggests that the thyroid hormone(s) also play a key role in regulation of immune functions by acting on immuno-competent cells through its receptor TR-a. Altered thyroid status is responsible for imbalances in antioxidant-pro-oxidant level in lymphoid organs. Melatonin being a well-known endogenous antioxidant effectively combats oxidative stress in lymphoid tissues induced by altered thyroid hormones. Most of evidences exist supporting that melatonin influences CFU-GM function. How the thyroid gland dysfunction influences immune status and bone marrow CFU-GM function is a question for neuro-endocrinologists as melatonin and thyroid hormone both influences immunity. The review encompasses the role of melatonin in regulation of bone marrow function and thyroid function whose interaction is finally responsible in regulation of immunity in normal and clinical conditions. These interactions can be easily judged by the expression of MT1 and TR-a in lymphoid organ which can throw a light in multifarious hypothesis of immune regulation to explain various clinical challenges. Thus, having diverse beneficial functions melatonin could be a potent therapeutic agent to treat the immuno-compromised state of an individual. © 2017 Nova Science Publishers, Inc.