The Evolution of Drugs on Schistosoma Treatment: Looking to the Past to Improve the Future

Abstract

Schistosomiasis is a devastating worldwide widespread tropical disease that currently affects more than 230 million people, making it an issue of great socioeconomic and public health importance. Unfortunatelly there is a single drug for the treatment of all forms of schistosomiasis, praziquantel, which was introduced in therapy in 1980. The article goes by antimony compounds, emetine, hydantoin, nitrofurans, lucanthone, hycanthone, oxamniquine derivatives and organophosphates until it finally gets to praziquantel derivatives. The intent of this review is to provide a panorama of drugs that were and are being used in human chemotherapy looking to the past to improve rational design drugs in the future. Not only clinical used compounds will be shown but also synthesized and tested compounds in vitro and in vivo in animal models which haven't yet to be used in humans. Prospects for drug discovery and vaccines to be used in the treatment and prevention of schistosomiasis, clinical trials, concerns about the resistance/decreased effectiveness of the treatment, and patent database will also be discussed. At the end of the review the reader will notice that much has been done but much still needs to be done yet.

Exposure to hycanthone alters chromatin structure around specific gene functions and specific repeats in Schistosoma mansoni

“…Since hycanthone is not anymore used for treatment of bilharzia and the use of oxamniquine is depreciated (Galdino da Rocha Pitta et al, 2013), mechanism of resistance is more of academic interest. However, experience with hycanthone and oxamniquine shows that a new conceptual framework is necessary to design experiments that distinguish the part of genetics and epigenetics in resistance phenotypes.…”

“…Bilharzia is an endemic disease in many areas in Africa and South America, infecting 67 million people and causing an important socio-economical burden (King, 2010). Since the beginning of the twentieth century, several schistosomicides were developed (Galdino da Rocha Pitta et al, 2013). Many of them were abandoned due to low treatment efficiency, as well as toxic and sometimes mutagenic side effects to the human host (Galdino da Rocha Pitta et al, 2013).…”

“…Since the beginning of the twentieth century, several schistosomicides were developed (Galdino da Rocha Pitta et al, 2013). Many of them were abandoned due to low treatment efficiency, as well as toxic and sometimes mutagenic side effects to the human host (Galdino da Rocha Pitta et al, 2013). Another major concern regarding schistomicides is the rapid appearance of resistances, both in laboratory strains and natural populations of the parasite (Bruce et al, 1987; Coles et al, 1987; Drescher et al, 1993; WHO, 1998).…”

New scope on the relationship between rotifers and Biomphalaria alexandrina snails

“…In SG II-A, two swimming motion types were the most commonly noticed throughout the four weeks; prompt linear progressive (1) and zigzag (2) swimming motions. These two swimming patterns were temporarily interrupted by cercarial pausing with random motions (4).…”

“…The disease has significant economic and public health consequences on affected populations in the diseaseendemic developing countries in Africa, South America and South-East Asia. Schistosomiasis continues to be a serious health problem, where exposure to infective cercariae results in more than 200 million cases worldwide [1][2][3] .…”