China
Africa
Explore chapters and articles related to this topic
Fertilized Sea Urchin Eggs as a Model for Detecting Cell Division Inhibitors
Published in Adorjan Aszalos, Modern Analysis of Antibiotics, 2020
Robert S. Jacobs, Leslie Wilson
A group of cyclic polysulfides from C. californica obtained from the Pacific at Isla San Jose, Mexico, were isolated and purified when crude fractions were found to have antibiotic activity against V. anguillarium [71]. One of these compounds (JF-23) was shown to have weak inhibiting activity in both the cell division assay (Figure 1) and the microtubule assembly assay (Table 3). These types of structures are relatively rare in nature, and the compound was included in this study primarily because of its novel structure.
Nutraceuticals for Hypertension Control
Published in Nilanjana Maulik, Personalized Nutrition as Medical Therapy for High-Risk Diseases, 2020
Balázs Varga, Mariann Bombicz, Andrea Kurucz, Béla Juhász
The major components of alliums, including onion, are organopolysulfides. The preventive potency of polysulfides in different chronic diseases including cancer, obesity, metabolic syndrome, gastric ulcer and cardiovascular disorders are well-known. The mechanism of polysulfides in cardioprotection are based on its hydrogen sulfide (H2S) donor property. H2S, next to nitric oxide (NO) and carbon monoxide (CO), is the third gasotransmitter and synthesized enzymatically from l-cysteine or l-homocysteine. H2S exerts its endotheliumdependent vasorelaxation by three main mechanisms: 1) activating NO synthase and inhibiting cGMP degradation by phosphodiesterase 5 (PDE5), thus potentiating the effect of NO-cGMP pathway; 2) H2S-derived polysulfides directly activate protein kinase G; and finally 3) H2S interacts with NO to form nitroxyl (HNO)-a potent vasorelaxant (Beltowski and Jamroz-Wisniewska 2014). Sakai et al. support this with their in vivo experiment on NO synthase inhibitor-induced hypertensive rats and spontaneously hypertensive rats (2003).
Cyanides, sulfides, and carbon monoxide
Published in Bev-Lorraine True, Robert H. Dreisbach, Dreisbach’s HANDBOOK of POISONING, 2001
Bev-Lorraine True, Robert H. Dreisbach
Hydrogen sulfide is released spontaneously by the decomposition of sulfur compounds and is found in petroleum refineries, tanneries, mines, and rayon factories. It is produced by bacterial action on sewage effluents containing sulfur compounds when dissolved O2 has been consumed owing to excessive organic loading of surface water. Such compounds are used by the canning industry as antioxidants during certain seasons and in many instances are discharged to surface waters, where they drastically reduce dissolved O2. Carbon disulfide is used as a solvent, especially in the rayon industry. Mercaptans are released in petroleum refining and are used as warning odors in liquefied propane, butane, and natural gas. Phenylmercaptan and p-chlorophenyl mercaptan are used as pesticides. Calcium polysulfide (Vleminckx’s solution), sodium sulfide, ammonium sulfide, and thioacetamide release hydrogen sulfide in contact with water or acids. Propane sultone is used as a chemical intermediate.
Role of nanotechnology in the prolonged release of drugs by the subcutaneous route
Published in Expert Opinion on Drug Delivery, 2023
At the EMA, nanosystems are classified based on their biological or nonbiological origins. For approval, a comparison with the reference formulation in terms of bioequivalence, safety, quality, and efficacy is needed [118]. However, because the interplay between nanosystem physicochemical characteristics and pharmacokinetic properties is not understood, replacing traditional animal models with more adequate models may allow extrapolation with greater certainty and safety. Nevertheless, the EMA has already published several reflection papers to help the industry develop its nanosystems and expedite its market entry [116]. Assessing the immunostimulatory profile of every nanosystem more precisely to determine whether the loaded drug plays a major role may avoid interference from background immunostimulation due to the nanosystem. Unloaded blank PEG-polysulfide nanosystems elicit low immunomodulatory activity [26], whereas comparable PLGA nanosystems [119] lead to alterations in immune cell populations and coreceptor expression and changes in the inflammatory status.
Glutathione Trisulfide Prevents Lipopolysaccharide-induced Inflammatory Gene Expression in Retinal Pigment Epithelial Cells
Published in Ocular Immunology and Inflammation, 2022
Hiroshi Tawarayama, Noriyuki Suzuki, Maki Inoue-Yanagimachi, Noriko Himori, Satoru Tsuda, Kota Sato, Tomoaki Ida, Takaaki Akaike, Hiroshi Kunikata, Toru Nakazawa
Glutathione, the principal in vivo antioxidant in animals, can directly quench intracellular reactive oxygen species (ROS) during thiol-dependent redox reactions mediated by glutathione disulfide reductase (GSR) and glutathione peroxidase (GPX)1.16 Increasing evidence demonstrates in vivo biosynthesis of sulfane sulfur-containing glutathiones (glutathione polysulfides and persulfides), and their physiological functions under normal and pathological conditions.17–25 Glutathione polysulfides, including glutathione trisulfide (GSSSG), exert stronger ROS-quenching activities than glutathione disulfide (GSSG) in the presence of GSR via conversion to their reduced forms, which are highly reactive.18,19 We have previously found that the GSSSG concentration in the aqueous humor of diabetic retinopathy patients, who suffer from excessive oxidative stress and inflammation, is significantly increased relative to that in the control patients.19 This observation suggests that GSSSG counteracts the increased oxidative stress in diabetic retinopathy patients. ROS function as secondary messengers that regulate immune responses and the expression of inflammatory genes by modulating the activities of nuclear factor-kappa B (NF-κB), mitogen-activated protein kinases (MAPKs), and inflammasomes.26–33 Therefore, GSSSG might be useful for attenuating cellular inflammation since this compound is more effective than GSSG in quenching ROS.
Recent efforts in drug discovery on vascular inflammation and consequent atherosclerosis
Published in Expert Opinion on Drug Discovery, 2021
Alma Martelli, Valentina Citi, Vincenzo Calderone
Thus, these pleiotropic drugs represent a very valid first-line choice in those clinical conditions of diabetes or hypercholesterolemia which are almost always associated with the risk of endothelial dysfunction. However, for the purpose of a preventive approach during the subclinical phases in healthy subjects (e.g. individuals who are approaching senescence but who do not have full-blown cardiovascular or metabolic pathologies), the nutraceutical approach seems to represent an extremely promising and effective strategy. Many natural substances present in food, if properly dosed and managed, are endowed with interesting antioxidant and anti-inflammatory activities, due to well-defined pharmacological mechanisms of action. These substances, such as resveratrol, garlic polysulfides, or cruciferous isothiocyanates, can truly represent an effective, safe, and modern approach to the prevention of vascular inflammation and endothelial dysfunction.