Nanointerventions in the Treatment of Protozoan Livestock Diseases

Protozoan diseases of veterinary importance such as trypanosomiasis, theileriosis, babesiosis, anaplasmosis, toxoplasmosis, and coccidiosis pose a major threat to the livestock and poultry population in terms of mortality, decreased production, and draught strength, which has prompted the customization of effective control strategies. Conventional synthetic antiprotozoal drugs often fail to target intracellular parasites enhancing drug-dose requirement along with poor biodistribution and pharmacokinetic properties. Off-target cytotoxicity, residual effect, and emergence of drug resistance are the outcomes. Although ethnobotanicals have brought some promise as an alternative strategy, but variability in their bioactive constituents imposing difficulty to dose determination and lack of interest of the stakeholders towards their application in parasitic diseases has resulted underutilization of the strategy. Another aspect, control of arthropod vectors of these protozoan diseases using synthetic acaricides has threatened the environmental safety along with evolution of acaricide resistance among the vectors. Therefore, nanointervention has become inevitable to address the multi-directional issues of controlling protozoan diseases. In terms of enhancing the efficacy of conventional drugs, nano-carrier based targeting and controlled release system lowers the drug-dose requirement, improves pharmacokinetics, as well as curtails the toxicity. Polymeric nanoparticles have found niche application to formulate various nano-delivery systems. Various metallic and metal oxide nanoparticles have shown inherent biocidal actions. Therefore, green synthesis of these materials has drawn significant attention as an eco-friendly strategy of protozoan control. Further, several plant-derived essential oils in their nanoformulation or under nano-encapsulation have found to be effective in the control of protozoan parasites and their arthropod vectors too, strengthening their application as eco-friendly biocompatible pesticides. The report of emerging resistance against these novel nanoformulations is also negligible, thus extending another advantage. So, the potential of nanotherapeutics in protozoal control is ample, but the execution adhering to the standards and regulations needs substantial stringency to convert this promise to a sustainable strategy for the control of protozoan diseases.