Ricin Toxicity and the Versitility of Molecular Biology
The field of molecular biology is versatile and ever evolving, it has to be since life is ever evolving. One of the things I have picked up in just reading a few articles pertaining to molecular biology is that as soon as people understand HOW something occurs in a living system the next question is immediately "how do we use that system to our advantage" and it leads to incredible discoveries in areas that would likely have not been considered prior to the birth of this field. One such example that I am going to delve into is the wild world of the ricin toxin. Ricin is one of the most poisonous naturally occurring substances known (as of April 2016) but as soon as its' biological processes were understood the next step was turning the harmful parts of it into beneficial ones.
Ricin is a highly potent toxin has quite an interesting history going from umbrella guns to cures for cancer. The toxin is found in the seeds of castor beans which typically grow in tropical regions. The bean itself is actually very commonly cultivated for its oil, which is used in medicine as well as cosmetics. The oil does not contain the toxin due to ricin not separating into the oil phase when extracted, so the oil is safe to use. The seeds are even edible due to the seed coat providing a somewhat protective shell, this also means the safest way to consume them is to eat them whole.
The ricin toxin is one of the most deadly naturally occurring toxins and there are many ways that it can effect living cells. Inhalation is the most potent pathway with a LD50 of only 3 μg/kg. While this is the most potent form of ricin intoxication is is the least common. Oral ingestion is the second most potent with an LD50 of 20mg/kg and other forms of intoxication are intramuscular which can be fatal after only a few days. Symptoms of ricin intoxication vary depending on the method of intoxication if it is ingested orally this can cause low blood pressure, vascular collapse, GI necrosis, and kideny failure. Inhalation causes loss of blood flow due to decreased oxygen. In mice that were injected with the toxin symptoms relating to oxygen and blood flow were present as well.
So, how does this deadly toxin do it? Ricin is a ribosome- inhibiting toxin and a pretty good one as well, once it actually attaches to the 28S ribosomal RNA on the 60S subunit, it can deactivate between 1500- 2000 ribosomes per minute. The toxin not only stops production of proteins at the ribosome causing rapid decline of cell function, it is also not cell specific which, as it suggests, means that the toxin can effect any cell it is able to wiggle into. The reason that many symptoms are lung or blood related is likely due to how the toxin usually enters the body and which cells it has easier access too.
Historically the ricin toxin was used for sparing attempts at bio warfare. There have been quite a few small cases including two attempts at intoxicating the former President Barack Obama with a ricin coated letter. Ricin toxin was even considered a potential weapon of war by the United States Department of war in 1918. By far the most famous case of ricin intoxication is the assassination of Georgi Markov, a Bulgarian BBC journalist. In 1978 a 'Bulgarian umbrella' was used to shoot Markov in the leg with an intoxicated bullet. Markov received 500μg of ricin and in three days he was dead. The potential to cause harm is so prominent, high risk groups are actually advised to get vaccines to prevent against intoxication.
With all this bad press however ricin also has the potential to (possibly) do a tremendous amount of good. Currently there is work being done to modify the toxin so that it targets and kills cancer cells rather than beneficial ones.
Over time, our understanding of the world has grown at an incredible rate and especially our understanding of information about how living systems work. In this particular example, people are now able to turn a massively damaging toxic pathway and look at how that can be redirected into a beneficial one. This to me, really speaks to the vastness and infinite possibility that science and particularly in this case molecular biology have to offer.
Moshiri, Mohammad, Fatemeh Hamid, and Leila Etemad. “Ricin Toxicity: Clinical and Molecular Aspects.” Reports of Biochemistry & Molecular Biology4.2 (2016): 60–65. Print.
Ricin is a highly potent toxin has quite an interesting history going from umbrella guns to cures for cancer. The toxin is found in the seeds of castor beans which typically grow in tropical regions. The bean itself is actually very commonly cultivated for its oil, which is used in medicine as well as cosmetics. The oil does not contain the toxin due to ricin not separating into the oil phase when extracted, so the oil is safe to use. The seeds are even edible due to the seed coat providing a somewhat protective shell, this also means the safest way to consume them is to eat them whole.
The ricin toxin is one of the most deadly naturally occurring toxins and there are many ways that it can effect living cells. Inhalation is the most potent pathway with a LD50 of only 3 μg/kg. While this is the most potent form of ricin intoxication is is the least common. Oral ingestion is the second most potent with an LD50 of 20mg/kg and other forms of intoxication are intramuscular which can be fatal after only a few days. Symptoms of ricin intoxication vary depending on the method of intoxication if it is ingested orally this can cause low blood pressure, vascular collapse, GI necrosis, and kideny failure. Inhalation causes loss of blood flow due to decreased oxygen. In mice that were injected with the toxin symptoms relating to oxygen and blood flow were present as well.
Historically the ricin toxin was used for sparing attempts at bio warfare. There have been quite a few small cases including two attempts at intoxicating the former President Barack Obama with a ricin coated letter. Ricin toxin was even considered a potential weapon of war by the United States Department of war in 1918. By far the most famous case of ricin intoxication is the assassination of Georgi Markov, a Bulgarian BBC journalist. In 1978 a 'Bulgarian umbrella' was used to shoot Markov in the leg with an intoxicated bullet. Markov received 500μg of ricin and in three days he was dead. The potential to cause harm is so prominent, high risk groups are actually advised to get vaccines to prevent against intoxication.
With all this bad press however ricin also has the potential to (possibly) do a tremendous amount of good. Currently there is work being done to modify the toxin so that it targets and kills cancer cells rather than beneficial ones.
Over time, our understanding of the world has grown at an incredible rate and especially our understanding of information about how living systems work. In this particular example, people are now able to turn a massively damaging toxic pathway and look at how that can be redirected into a beneficial one. This to me, really speaks to the vastness and infinite possibility that science and particularly in this case molecular biology have to offer.
Moshiri, Mohammad, Fatemeh Hamid, and Leila Etemad. “Ricin Toxicity: Clinical and Molecular Aspects.” Reports of Biochemistry & Molecular Biology4.2 (2016): 60–65. Print.
Fantastic commentary on ricin! I had no idea what this toxin was but feel well informed after reading this post. I am especially astounded at it's potent nature, yet it's oil can be extracted and used safely in cosmetics and medicines. It is super intriguing that they are doing research on its potential to target cancer cells. Wow! It's so funny in science, like you mentioned, that many of the harmful toxins and bacterias, etc. can have beneficial uses when studied in depth. I guess there is a good side to everything.
ReplyDeleteAs soon as anyone dies a ricin related death, its always like, "that botanist seems suspicious".
ReplyDelete