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Terpenoids: The Biological Key Molecules
Published in Dijendra Nath Roy, Terpenoids Against Human Diseases, 2019
Moumita Majumdar, Dijendra Nath Roy
The animal cell contains abundant variations of hormones, which are the principal regulators and modulators of cell signalling in the different catabolic and anabolic pathways. One of the important pathways is glucocorticoid signalling. This pathway is under the tight regulation of receptor and ligand interaction. Glucocorticoid receptors (GRs) are activated, forming GR complexes, and are involved in the up-regulation of various anti-inflammatory protein-expressing genes inside the nucleus through transactivation; they also down-regulate pro-inflammatory protein coding genes in the cytoplasm through transrepression (Rhen and Cidlowski 2005). Recent findings have shown that modulation in the growth and homeostasis of T lymphocytes is also achieved by glucocorticoids, which also have a role in T-cell signalling (Pazirandeh et al. 2002).
Microbial Transformation of Steroids and Sterols
Published in Nduka Okafor, Benedict C. Okeke, Modern Industrial Microbiology and Biotechnology, 2017
Nduka Okafor, Benedict C. Okeke
The greatest portion of steroid drug production is aimed at the synthesis of glucocorticoids which are highly effective agents for the treatment of chronic inflammation. Glucocorticoids exert their effects by binding to the cytoplasmic glucocorticoid receptor within the target cell and thus either increase or decrease transcription of a number of genes involved in the inflammatory process. Specifically, glucocorticoids down-regulate potential mediators of inflammation such as cytokines. Typical oral glucocorticoids used to treat rheumatoid arthritis are prednisone and 6-α-methylprednisolone. Corticosteroids are the most efficacious treatment available for the long-term treatment of asthma, and inhaled corticosteroids are considered to be a first-line therapy for asthma. They are also used to treat rhinitis, nasal congestion, and inflammations of the skin.
Pulmonary infection induced by drugs
Published in Philippe Camus, Edward C Rosenow, Drug-induced and Iatrogenic Respiratory Disease, 2010
Marc B Feinstein, Dorothy A White
Glucocorticoids are thought to exert their effects via three separate pathways. First, glucocorticoid molecules may bind to the glucocorticoid receptor in the cytoplasm. The resultant glucocorticoid–glucocorticoid receptor complex then migrates to the nucleus where it attaches to glucocorticoid response elements on the DNA, inducing transcription. Production of annexin I, an inhibitor of cytosolic phospholipase A2α (and therefore an indirect inhibitor of eicosanoid production), is thought to operate by this mechanism.4,5 Second, the glucocorticoid–glucocorticoid receptor complex may directly modulate the activity of other inflammatory transcription factors. The transcriptional activity of nuclear factor-κB, for instance, a pro-inflammatory transcription factor that stimulates production of numerous cytokines, chemokines, adhesion molecules and receptors, is thought to be blocked by the glucocorticoid–glucocorticoid receptor complex.6 Finally, glucocorticoids may bind directly to receptors on the cell surface, without entering the cytoplasm, thereby activating secondary messenger systems. Glucocorticoids also lead to a reduction in all circulating leucocytes, with the exception of neutrophils, which demarginate from the vessel wall and are found in increased numbers in the blood. Detachment of neutrophils from the vessel walls diminishes the ability of these cells to exit the blood stream and enter sites of infection.
The combined effects of noise and vibration stress on sex hormone levels, fertility capacity, and the protective role of cinnamon extract in rats: an experimental study
Published in Archives of Environmental & Occupational Health, 2022
Hamideh Pirami, Ali Khavanin, Farshad Nadri, Ali Tajpoor, Younes Mehrifar, Zohreh Mazaheri Tirani
Physiological levels of LH, FSH, and testosterone play key roles in spermatogenesis, and decreased levels of these hormones can be an important factor in structural changes in seminiferous tubules and damage to testicular tissue. Spermatogenesis is a very dynamic process that is sensitive to stressors, so oxidative stress can have adverse effects on spermatogenesis and Leydig cells.59 Stress activates the hypothalamic-pituitary-adrenal axis (HPA axis), which induces an increase in glucocorticoid release and a decrease in testosterone production in Leydig cells by the glucocorticoid receptor. In stressful situations, it increases the secretion of androgens secreted by the adrenal glands, such as dehydroepiandrosterone (DHEA), which through a negative feedback mechanism leads to a decrease in testosterone production.60