title: Unusual thiol-based redox metabolism of parasitic flukes.
abstract: Parasitic flukes are exposed to free radicals and, to a greater extent, reactive oxygen species (ROS) during their life cycle. Despite being relentlessly exposed to ROS released by activated immune cells, these parasites can survive for many years in the host. Cellular thiol-based redox metabolism plays a crucial role in parasite survival within their hosts. Evidence shows that oxidative stress and redox homeostasis maintenance are important clinical and pathobiochemical as well as effective therapeutic principles in various diseases. The characterization of redox and antioxidant enzymes is likely to yield good target candidates for novel drugs and vaccines. The absence of active catalase in fluke parasites offers great potential for the development of chemotherapeutic agents that act by perturbing the redox equilibrium of the cell. One of the redox-sensitive enzymes, thioredoxin glutathione reductase (TGR), has been accepted as a drug target against blood fluke infections, and related clinical trials are in progress. TGR is the sole enzyme responsible for Trx and GSH reduction in parasitic flukes. The availability of helminth genomes has accelerated the research on redox metabolism of flukes; however, significant achievements have yet to be attained. The present review summarizes current knowledge on the redox and antioxidant system of the parasitic flukes.
authors.affiliation: Molecular and Structural Biophysics Laboratory, Department of Biochemistry, North-Eastern Hill University, Shillong 793022, India. Electronic address: timir.tripathi@gmail.com.
authors.forename: Timir
authors.initials: T
authors.lastname: Tripathi
authors.affiliation: WHO Collaborating Centre for Research and Control of Opisthorchiasis, Tropical Disease Research Centre, Department of Pathology, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand.
authors.forename: Sutas
authors.initials: S
authors.lastname: Suttiprapa
authors.affiliation: WHO Collaborating Centre for Research and Control of Opisthorchiasis, Tropical Disease Research Centre, Department of Pathology, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002, Thailand. Electronic address: banchob@kku.ac.th.
authors.forename: Banchob
authors.initials: B
authors.lastname: Sripa
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000378:metabolism*; D003004:Clonorchis sinensis / Q000378:metabolism*; D009891:Opisthorchis / Q000378:metabolism*; D010084:Oxidation-Reduction; D013438:Sulfhydryl Compounds / Q000378:metabolism*
chemical_list: D000975:Antioxidants; D013438:Sulfhydryl Compounds
keywords: Glutathione; Liver fluke; Parasites; Redox; Thiol; Thioredoxin glutathione reductase