Article Review

This article talks about an experiment testing two new drugs on Trypanosomiasis, or sleeping sickness. Sleeping Sickness is caused by the bite of the Tsetse fly, which injects the Trypanosoma parasite, of which there are a three different known kinds. However, this experiment focused exclusively on Trypanosoma Brucei, which is not toxic to humans, but is found in animals in the same region of sub saharan africa, mostly livestock. The two new drugs tested are both alkaloids derived from plants: emetine and homoharringtonine. The study tested the effectiveness of these drugs in five different ways: through testing the level of protein synthesis, through testing the mitochondrial membrane of the parasite itself inside of cells, through testing to see if the cell cycle was arrested, as well as testing DNA intercalculation (mutations in parasite genetic formula) and finally the drugs ability to inhibit an enzyme specific to the Trypanosoma Brucei. Cell cultures were soaked in a solution containing either of these drugs in different concentrations. After two hours in the soak and forty eight to rest, the growth rate of the parasites were reduced by fifty and thirty percent, in the highest concentration of the emetine and homoharringtonine respectively. After four hours at any concentration of emetine, the growth was slowed by sixty, seventy, and eighty percent at intervals of a day. The homoharringtonine was more effective in stopping protein synthesis, slowing the parasites by fifty percent, while the comparable concentration of emetine only slowed by twenty. However, neither drug was effective compared to the control at weakening the mitochondrial membrane after four hours. Homoharringtonine was slightly effective after twenty four hours of a soak.  After a four hour soak, homoharringtonine arrested cells in between the G0 and G1 phases. However, after twenty four hours, the effect was diminished. Emetine stopped the cell cycle in the G2 and M phases, but only after a twenty four hour soak. Neither drug incubation could do anything to reduce the level of the enzyme concentration. Emetine could intercalate DNA, but the homoharringtonine was unable to. All in all, it seems as if homoharringtonine is more effective than emetine at fighting the parasite. However, the most important thing to keep in mind about the study is that these alkaloids are not healthy for humans to have in their systems. Therefore, no matter what, it is best that these drugs would be used in moderation. The writer of the article says that because sleeping sickness is life threatening, the benefits outweigh the costs. Either way, human subjects would knowingly be injecting bleach into their bodies. Also important is these drugs even if they did become widespread, would only be used to treat stage one of the disease. Once the parasite crosses the blood brain barrier, it would require an entirely new treatment. This second stage is also one that we are under equipped to deal with. Of the few medicines we have for treatment, only two are available for the second stage. Therefore, despite how promising this study might be, it is far better to focus our efforts on prevention, namely education and eradication of the tsetse fly.


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