Chandana Haldar

Bio: Chandana Haldar is an academic researcher from Banaras Hindu University. The author has contributed to research in topics: Melatonin & Pineal gland. The author has an hindex of 25, co-authored 161 publications receiving 1964 citations. Previous affiliations of Chandana Haldar include Semmelweis University.

Human pineal gland: Histomorphological study in different age groups and different causes of death

Abstract: Introduction In human, the age dependent changes in the micro-anatomy and histology of different organs are most prevalent along with causes of death. As pineal is a neuro-endocrine gland and is target of various hormones of physiological importance hence, the effect of age and different unnatural causes of death may affect its histology. This aspect of histomorphology has never been studied previously. Therefore, aim of the present study was to evaluate the changes in morphology and histology of human pineal gland in different age groups in relation to different causes of death. Methods We collected human samples from young (5–20 yrs), middle aged (21–55 yrs) and old aged (56–95 yrs) individuals under different causes of death like septicemia (S), poisoning (P), hanging (H), burning (B), injury (I) and other reasons which are regarded as control (C) and were processed for morphometric and histological observations. Results Anatomically significant decrease in pineal weight, length, breadth was noted in an age dependent manner. Histological observations suggest a significant increase in numbers as well as size in pineal concretions with increasing age. Further, huge degeneration of pinealocytes and neuronal glial cells was observed upon poisoning and burning cases in comparison to control. But in case of hanging, septicemia and injury there was no significant difference in comparison to control. Discussion It may be concluded that not only the age but also the different causes of death may severely affect the basic micro-architecture of human pineal gland.

Synthesis, Characterization, and Evaluation of Toxicity of Melatonin-Loaded Poly (D,L-Lactic Acid) Nanoparticles (Mel-PLA-Nanoparticles) and Its Putative Use in Osteoporosis

Abstract: Melatonin-loaded PLA nanoparticles are nowadays important in biological system for its biodegradable nature for targeted drug delivery. Hence, aim of the study is to note applicability and toxicity of Mel-PLA nanoparticles in osteoporosis. Different concentrations of melatonin and PLA were prepared by dissolving in dichloromethane (DCM). The final dried nanoparticles were used for structural analysis by SEM, TEM, and FTIR. Toxicity and immunological impact of nanoparticles were evaluated on rats: control and nanoparticle treated (n = 5/group) for 7 days. Afterward animals were sacrificed and blood, liver, and kidney were collected. A fraction of blood was processed for TLC, DLC, and %LC, and the remaining was centrifuged at 3000x g at 4 °C for 30 min. Separated plasma was used for measurements of IL-2, IL-6, TNF-α, IFN-γ, IL-1β, urea, creatinine, and BUN. Both plasma and tissue homogenates were used for AST, ALT, ACP, and ALP estimations. We noted significantly high (p 0.05) or unaffected (IFN-γ, ACP, and ALP). From our preliminary study, we may conclude that we have synthesized Mel-PLA nanoparticles and their effects were nontoxic to animals.

Trade-off expression of melatonin receptor subtypes (Mel1a and Mel1b) and androgen receptor in lung of a tropical bird, Perdicula asiatica.

Abstract: The role of circulatory steroid hormone along with melatonin in lung of any seasonally breeding bird has never been explored so far. This could be interesting because steroid hormones are immunosuppressive while melatonin is immunostimulatory in nature. In our present study, we report the effect of exogenous melatonin and testosterone on expression of melatonin receptor subtypes (Mel1a and Mel1b ) and androgen receptor in lung of a tropical bird Perdicula asiatica. Birds were collected from vicinity of Varanasi and acclimatized in laboratory with sufficient food and water. The birds were treated with melatonin and testosterone at dose of 25 µg/100 g B.wt./day and 1 mg/100 g B.wt./day, respectively, for 28 days. At the end of the experiment, the birds were sacrificed and lung tissue and blood sample were collected for immunohistochemistry, Western blot analysis and hormonal assay. Testosterone treatment increased circulatory testosterone and upregulated expression of androgen receptors whereas downregulated expression of melatonin receptor subtypes Mel1a and Mel1b . Melatonin administration increased peripheral melatonin and upregulated expression of melatonin receptor subtypes Mel1a and Mel1b while downregulated androgen receptor. Thus, our results suggest that a trade-off relationship between melatonin and testosterone exists in regulation of their receptors in lung of Perdicula asiatica.

Controlled drug delivery vehicles for cancer treatment and their performance.

Abstract: Although conventional chemotherapy has been successful to some extent, the main drawbacks of chemotherapy are its poor bioavailability, high-dose requirements, adverse side effects, low therapeutic indices, development of multiple drug resistance, and non-specific targeting. The main aim in the development of drug delivery vehicles is to successfully address these delivery-related problems and carry drugs to the desired sites of therapeutic action while reducing adverse side effects. In this review, we will discuss the different types of materials used as delivery vehicles for chemotherapeutic agents and their structural characteristics that improve the therapeutic efficacy of their drugs and will describe recent scientific advances in the area of chemotherapy, emphasizing challenges in cancer treatments.

Generation of the Melatonin Endocrine Message in Mammals: A Review of the Complex Regulation of Melatonin Synthesis by Norepinephrine, Peptides, and Other Pineal Transmitters

Abstract: Melatonin, the major hormone produced by the pineal gland, displays characteristic daily and seasonal patterns of secretion. These robust and predictable rhythms in circulating melatonin are strong synchronizers for the expression of numerous physiological processes in photoperiodic species. In mammals, the nighttime production of melatonin is mainly driven by the circadian clock, situated in the suprachiasmatic nucleus of the hypothalamus, which controls the release of norepinephrine from the dense pineal sympathetic afferents. The pivotal role of norepinephrine in the nocturnal stimulation of melatonin synthesis has been extensively dissected at the cellular and molecular levels. Besides the noradrenergic input, the presence of numerous other transmitters originating from various sources has been reported in the pineal gland. Many of these are neuropeptides and appear to contribute to the regulation of melatonin synthesis by modulating the effects of norepinephrine on pineal biochemistry. The aim of this review is firstly to update our knowledge of the cellular and molecular events underlying the noradrenergic control of melatonin synthesis; and secondly to gather together early and recent data on the effects of the nonadrenergic transmitters on modulation of melatonin synthesis. This information reveals the variety of inputs that can be integrated by the pineal gland; what elements are crucial to deliver the very precise timing information to the organism. This also clarifies the role of these various inputs in the seasonal variation of melatonin synthesis and their subsequent physiological function.