Research and development of antischistosomal drugs in the People's Republic of China a 60-year review

A comprehensive 60-year review of antischistosomal drug discovery and development research in the People's Republic of China (P.R. China) is presented. In the 1950s, three antimonials were developed, which, compared to potassium antimony tartrate-the treatment of choice against schistosomiasis at the time-showed equal efficacy but lower toxicity when administered orally or intramuscularly. Activity of furapromidum against Schistosoma japonicum was reported in the early 1960s, and this drug became the first non-antimonial used in clinical treatment of schistosomiasis japonica. Subsequently, two additional nitrofuran derivatives (furadiamine and fuvinazole) were investigated in the laboratory and clinically. In the late 1960s, niridazole and amoscanate were developed by western scientists, which encouraged Chinese researchers to synthesise and further modify the chemical structures of these compounds. However, the modified compounds were less efficacious but similarly toxic, which impeded their further development. The advent of the safe, highly efficacious broad-spectrum antischistosomal drug praziquantel, in the mid-1970s, eventually resulted in a change of the global schistosomiasis control strategy from a multi-pronged transmission control approach to drug-based morbidity control. Numerous studies were carried out in P.R. China to further the understanding of efficacy, mechanism of action and safety of praziquantel against S. japonicum. Efforts have also been made to develop antischistosomal drugs from Chinese traditional medicine, and research with cucurbitin (an amino acid isolated from pumpkin seeds), among other products, showed interesting in vitro and in vivo activities against S. japonicum. In the 1990s, the artemisinins-originally reserved for malaria treatment-were developed as 'chemoprophylactic' agents against S. japonicum, which in turn led to a series of new developments of artemisinins and related compounds as broad-spectrum antischistosomal and anthelminthic therapies.