Development of New Drugs to Treat Taenia solium Cysticercosis: Targeting 26 kDa Glutathione Transferase

Abstract

Taenia solium causes neurocysticercosis, a parasitic infection of the central nervous system in humans. The costs of management, treatment, and diagnosis of patients with neurocysticercosis are high, and some patients do not respond to the currently available treatments. Helminth cytosolic glutathione transferases (GSTs) are essential enzymes involved in the regulation of immune responses, transport, and detoxification. In T. solium, three cytosolic GSTs with molecular masses of 26.5 (Ts26GST), 25.5 (Ts25GST), and 24.3 kDa (TsMσGST), classified as mu-alpha, mu and sigma GST-classes, respectively, constitute the main detoxification system, and they may be immune targets for the development of vaccines and new anthelmintics. We performed a successful virtual screen, and identified I7, a novel selective inhibitor of Ts26GST that showed a non-competitive inhibition mechanism towards substrate glutathione with a Ki of 55.7 mM and mixed inhibition towards the electrophilic substrate 1-chloro-2,4-dinitrobenzene with a Ki of 8.64 mM. Docking simulation studies showed that I7 can bind to a site that is adjacent to the electrophilic site and the furthest from the glutathione site. This new inhibitor of Ts26GST will be used as a lead molecule to develop new effective and safe drugs against diseases caused by T. solium.