Showing papers by "Chandana Haldar published in 2015"

Melatonin as a possible antidote to UV radiation induced cutaneous damages and immune-suppression: An overview

Abstract: The sun rays brings along the ultraviolet radiations (UVRs) which prove deleterious for living organisms. The UVR is a known mutagen and is the prime cause of skin carcinomas. UVR causes acute oxidative stress and this in turn deteriorates other physiological functions. Inflammatory conditions and elevation of pro-inflammatory molecules are also associated with UVR mediated cellular damages. The inflammatory conditions can secondarily trigger the generation of free radicals and this act cumulatively in further deterioration of tissue homeostasis. Photoimmunologists have also related UVR to the suppression of not only cutaneous but also systemic immunity by different mechanisms. Some researchers have proposed the use of various plant products as antioxidants against UVR induced oxidative imbalances but Melatonin is gaining rapid interest as a product that can be utilized to delineate the pathological effects of UVR since it is an established antioxidant. Besides the antioxidative nature, the capacity of melatonin to attenuate apoptosis and more importantly the efficacy of its metabolites to further aid in the detoxification of free radicals have made it a key player to be utilized against UVR mediated aggravated conditions. However, there is need for further extensive investigation to speculate melatonin as an antidote to UVR. Although too early to prescribe melatonin as a clinical remedy, the hormone can be integrated into dermal formulations or oral supplements to prevent the ever increasing incidences of skin cancers due to the prevalence of the UVR on the surface of the earth. The present review focuses and substantiates the work by different photo-biologists demonstrating the protective effects of melatonin and its metabolites against solar UVR - Melatonin as a possible antidote to UV radiation induced cutaneous damages and immune-suppression: an overview. J Photochem Photobiol B.

Photoperiodic regulation of nuclear melatonin receptor RORα in lymphoid organs of a tropical rodent Funambulus pennanti: Role in seasonal oxidative stress

Abstract: The orphan nuclear receptor RORα of RZR/ROR family has been suggested to mediate the genomic actions of melatonin on the expression of antioxidant enzymes. However, no direct evidences exist. In the present study we explored the role of photoperiod (natural and artificial) in regulation of RORα and its association with the photoperiod induced antioxidant defense system in the lymphoid organs (spleen and thymus) of seasonally breeding, tropical squirrels, Funambulus pennanti. The photoperiod mediated regulation of antioxidant status was checked along with the RORα expression and circulatory melatonin level in the squirrels. The enhancement of the antioxidant capacity of serum and lymphoid organ was concomitant with the short photoperiod (10L:14D) induced high levels of plasma melatonin. Further, peripheral melatonin level enhanced the AANAT activity as well as the melatonin synthesis in the lymphoid tissues. RORα expression presented an inverse correlation with the plasma level of melatonin as well as the short day induced antioxidant enzyme activity in the lymphoid organs. The results suggest that for reduction of seasonal oxidative stress melatonin might not be utilizing the nuclear receptor RORα pathway; rather the rise in circulatory melatonin collectively with tissue specific melatonin might be protecting the splenic and thymic lymphocytes from the seasonal oxidative stress.

Synthesis and in vitro evaluation of melatonin entrapped PLA nanoparticles: an oxidative stress and T-cell response using golden hamster.

Abstract: This study was carried out to evaluate the effects of melatonin entrapped PLA nanoparticles (Mel-NPs) and pure Mel on impact of reactive oxygen species (ROS), blastogenic responses (%SR) in terms of proliferation of splenocytes. ROS have been proposed to play an important role in balancing the pro- and antioxidant homeostasis during different physiological condition of organism. Melatonin has been suggested as an effective free radical scavenger that may have an important role during this process. Mel-NPs were prepared by using emulsification (o/w) nanoprecipitation method and their physicochemical characterizations were studied for evaluation of particle size and encapsulation efficiency by using SEM, TEM, particle size analyzer, DSC and FTIR. The TEM micrograph showed excellent findings regarding size, shape, encapsulation efficiency and difference between pure PLA nanoparticles and Mel-NPs. The SEM micrographs of Mel-NPs showed spherical shape, smooth surfaces and the homogeneous particle size distribution. In TEM micrograph, the average diameter of Mel-NPs was found to be 36 ± 8 nm with ∼78% (w/w) of entrapment efficiency. The size of pure PLA nanoparticles was found to be larger as compared to Mel-NPs which confirm that the drug supports the reduction of the size of Mel-NPs. In in vitro study, we observed that Mel-NPs significantly reduce the level of ROS in splenocytes and increased the level %SR at 96 h of splenocytes culture as compared to the culture with pure Mel. Thus our results propose high clinical value for improvement of depressed immunity by Mel-NPs. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 103A: 3034–3044, 2015.

Effect of 2-deoxy-D-glucose induced metabolic stress on testicular steroidogenesis and antioxidant status in golden hamster, Mesocricetus auratus: Role of photoperiod.

Abstract: The driving force underlying the evolution of reproductive seasonality is the marked seasonal fluctuation in energy availability. It is well established that photoperiod regulates testicular steroidogenesis through modulation of circulatory and local melatonin levels and MT1R expression in golden hamster. However, photoperiodic variation in energy availability and its impact on testicular steroidogenesis and antioxidant status has never been investigated for any seasonal breeder. Therefore, the aim of the present study is to elucidate the role of photoperiod in modulation of metabolic stress induced variation in steroidogenesis and antioxidant status in testes. We experimentally reduced energy availability via administration of 2-deoxy-d-glucose (2-DG), a synthetic glucose analog, in critical- (CP), long- (LD) and short-day (SD) exposed golden hamsters, Mesocricetus auratus and examined testicular steroidogenesis and antioxidant status. Administration of 2-DG decreased testicular steroidogenesis and antioxidant enzyme activity in CP and LD experienced hamsters as compared to CP- and LD-control groups. Moreover, a decrease in the plasma- and local-melatonin level and MT1R expression in testes with a simultaneous increase in plasma corticosterone level was noted following 2-DG administration in CP and LD exposed hamsters. In contrast, no significant effect of 2-DG administration was observed on the parameters investigated under SD condition. Therefore, it can be suggested that the reduction in energy availability under CP and LD condition suppressed testicular steroidogenesis and increased oxidative damage in testis whereas SD induced melatonin might have buffered the 2-DG induced suppression of testicular steroidogenesis and maintained testicular antioxidant status.

Me11b receptor mediated action of melatonin in regulation of lung associated immune system (LAIS) of Perdicula asiatica: An in vitro study

Abstract: The pineal hormone melatonin plays an important role in immunomodulation of avian species. These immunomodulatory effects of melatonin are known to be mediated by three membrane bound receptors found in birds, Mel1a, Mel1b and Mel1c. However, specific involvement of these receptors in mediating immunomodulatory effects of melatonin in Lung Associated Immune System (LAIS) remains unexplored till date. The aim of the present study was to check the specific melatonin receptor subtype involved in regulation of LAIS. For this purpose, we used luzindole, a non selective and 4P-PDOT, a selective Mel1b receptor antagonist under in vitro condition to assess their specific potency towards melatonin induced cellular immunity in the lung tissue of Perdicula asiatica. Melatonin enhanced proliferation of lymphocytes isolated from lung tissue and up-regulated both receptor types (Mel1a and Mel1b) on physiological doses while higher doses decreased the proliferation and down regulated the expression of both receptors. Luzindole decreased proliferation of lung lymphocytes and down-regulated the expression of both receptors in a dose dependent manner while 4P-PDOT decreased proliferation of lymphocytes isolated from lung and down-regulated the expression of Mel1b receptor subtype only. Proliferation rate of lymphocytes isolated from lung tissue followed more the expression pattern of Mel1b than the Mel1a. Thus, we may suggest that Mel1b might be involved in cell mediated immunity in lung of P. asiatica to a greater extent than Mel1a.

Free radical load in lymphoid organs (spleen and thymus) of indian goat capra hircus: role of sex, season and melatonin

Abstract: Objective: Lymphoid organs (i.e. spleen and thymus) are important due to functional dynamicity. As a result, the generated free radicals may limit their function. Thus, present study was aimed to note seasonal and sex dependent variation in free radical status in Indian goat Capra hircus under the aegis of melatonin which is a well-known antioxidant. Methods: Markers of oxidative stress (i.e. Super Oxide Dismutase; SOD, Catalase; CAT, Glutathione Peroxidases; GPx) were measured by standardized protocols. Total Antioxidant Status (TAS) was measured by 2, 2′-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid; ABTS) radical cation method and Lipid Per Oxidation (LPO) was measured by Thiobarbituric acid reactive substances (TBARS) level. Glucocorticoid Receptor (GR) expression in lymphoid organs was noted by Western Blot analysis. The circulatory level of cortisol and melatonin were estimated by commercial ELISA kits. Results: We noted significantly high levels of SOD, Catalase, GPx activities and ABTS level in lymphoid organs during monsoon and low during winter. Malonaldehyde; MDA a marker for lipid peroxidation was significantly high during summer and was significantly low during monsoon and winter. Cortisol level was significantly high during monsoon whereas melatonin level was significantly high during winter. GR expression was significantly high in males during monsoon and winter, but the level was significantly high only during monsoon in females. Conclusion: All the results suggest that monsoon and winter are the seasons of stress and to buffer the elevated stress level, melatonin coupled both the roles of free radical scavenger (as a free molecule) and elevation of antioxidant enzymes.

Reproductive seasonality in the Indian pygmy field mouse, Mus terricolor

Abstract: The Indian pygmy field mouse, Mus terricolor, is a tiny, yet economically and ecologically important crop pest found throughout South-East Asia. There are no systematic reports exploring its reproductive physiology. We report the presence of distinct periods of annual reproductive activity and quiescence in M. terricolor. Body weight in males and females, relative weights of testis, epididymis and seminal vesicle in males, ovarian and uterine weight in females, gonadal histomorphic changes, testicular and ovarian cholesterol, sialic acid in epididymis, fructose in seminal vesicle, uterine protein content, melatonin in males and females, testosterone in males, estradiol, and progesterone in females were studied over a period of three years in both wild-caught and lab-acclimated mice. The number of Graafian follicles and corpora lutea, and plasma estradiol and progesterone, along with relative weights of ovary and uterus in females exhibited a peak in the months of October–January, compared to June. Based o...

Photic Stress Modulates Cholesterol Content and Oxidative Load of Steroidogenic Organs (Adrenal, Ovary and Testis) of Indian Spotted Finch Lonchura punctulata

Abstract: Steroidogenic organs such as adrenal gland and gonad are of vital importance in birds, as the adrenal gland regulates stress by modulating the levels of corticosterone, while gonads synthesize gonadal steroids that regulate breeding cycle. Cholesterol content in both adrenal and gonad reflect the physiological status of these organs for stress management and reproduction, respectively. Birds, being photosensitive, experience phototoxicity in the nature due to the rapid urbanization. If photic stress induced by constant dark (DD) and constant light (LL) influences steroidogenesis in terms of cholesterol content and total antioxidant status (TAS%) as a marker of stress was experimentally assessed in Indian spotted finch Lonchura punctulata along with measurement of peripheral corticosterone levels. DD was stressful and, hence, caused decrease of ovary / testis weight and increase of adrenal gland weight, while cholesterol content decreased significantly due to inhibition of steroidogenesis. LL stimulated gonadal function but caused decrease of cholesterol content suggesting active steroidogenesis. TAS% increased under DD and decreased under LL. The phototoxicity, whether in term of DD or LL, was stressful to Indian spotted finch as evident from increased adrenal gland weight and decreased cholesterol content that can be correlated with increased synthesis of corticosterone. It may be concluded that cholesterol content is an important marker of streroidogenic status, and extremes of photoperiod influence cholesterol content, corticosterone level and TAS%.

Immunophysiological Significance for Differential Receptor Expression of Melatonin (Mel1aR/Mel1bR), Cytokine(s) (IL-2R/IL-10R/TGF-òR) and Tyrosine Hydroxylase (THR) in Lymphocyte Sub-Population: A Novel Crosstalk between Melatonin and Catecholamines

Abstract: Retraction Note The article entitled “Immunophysiological Significance for Differential Receptor Expression of Melatonin (Mel1aR/Mel1bR), Cytokine(s) (IL-2R/IL-10R/TGF-β R) and Tyrosine Hydroxylase (THR) in Lymphocyte Sub-Population: A Novel Crosstalk between Melatonin and Catecholamines” has been accepted for publication in the Journal of Clinical and Cellular Immunology. Soon after publication of the paper in the Volume 6 Issue 4, the authors of the paper would like to retract the paper for their personal reasons. Therefore, the journal publisher disowns the paper from the issue 4 of volume 6. Hereafter the content of the paper may not available online in any of the publisher’s websites or related weblinks

FREE RADICAL LOAD IN LYMPHOID ORGANS (SPLEEN AND THYMUS) OF INDIAN GOAT CAPRA HIRCUS: ROLE OF SEX, SEASON AND MELATONIN Original Article

Abstract: Objective: Lymphoid organs (i.e. spleen and thymus) are important due to functional dynamicity. As a result, the generated free radicals may limit their function. Thus, present study was aimed to note seasonal and sex dependent variation in free radical status in Indian goat Capra hircus under the aegis of melatonin which is a well-known antioxidant. Methods: Markers of oxidative stress (i.e. Super Oxide Dismutase; SOD, Catalase; CAT, Glutathione Peroxidases; GPx) were measured by standardized protocols. Total Antioxidant Status (TAS) was measured by 2, 2′-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid; ABTS) radical cation method and Lipid Per Oxidation (LPO) was measured by Thiobarbituric acid reactive substances (TBARS) level. Glucocorticoid Receptor (GR) expression in lymphoid organs was noted by Western Blot analysis. The circulatory level of cortisol and melatonin were estimated by commercial ELISA kits. Results: We noted significantly high levels of SOD, Catalase, GPx activities and ABTS level in lymphoid organs during monsoon and low during winter. Malonaldehyde; MDA a marker for lipid peroxidation was significantly high during summer and was significantly low during monsoon and winter. Cortisol level was significantly high during monsoon whereas melatonin level was significantly high during winter. GR expression was significantly high in males during monsoon and winter, but the level was significantly high only during monsoon in females. Conclusion: All the results suggest that monsoon and winter are the seasons of stress and to buffer the elevated stress level, melatonin coupled both the roles of free radical scavenger (as a free molecule) and elevation of antioxidant enzymes.