Natural products against toxoplasma gondii and Leishmania tropica

Abstract

Parasitoses, including toxoplasmosis and cutaneous leishmaniasis, are infections that still pose health problems, which raise from moderate to even fatal outcomes, especially in low and middle income countries. Toxoplasmosis is caused by Toxoplasma gondii, a highly prevalent protozoan parasite, of medical, veterinary and economic impact. Following an acute infection, the disease evolves, under the tight control of the host immune system, into a persistent chronic toxoplasmosis (CT). In immunocompetent hosts, CT manifests as latent tissue cysts that impact host behavior and correlate with several neuro-pathologies and cancers. In immunocompromised patients, reactivation of CT can become life threatening. Several drugs are available to control acute toxoplasmosis (AT); however, they associate with side effects. Currently, there is no approved therapy affecting the viability and number of tissue cysts in CT, which urges the need for novel therapeutic strategies. Cutaneous leishmaniasis (CL) is a neglected tropical disease, classified by the WHO as one of the most uncontrolled spreading diseases with no recent advances in its treatment. CL was lately introduced to Lebanon, following the large-scale displacement of refugees from endemic Syria. Leishmania Tropica represents the predominant etiologic agent of CL in our region. Therapies against CL include physical and chemical methods. Among topical treatments, paromomycin and intralesional injections of pentavalent antimonials are widely used but seem to be less effective against L. tropica species. In addition, these compounds have several limitations, including the need for repetitive painful injections, high cost, poor availability, and known systemic toxicity. Therefore, it is of high interest to find novel drugs against CL. Microorganisms are well known for their ability to produce secondary metabolites. A significant number of clinically utilized medications are based on these natural products or their inspired derivatives. Actinomycetes are mainly soil dw