Although you don’t know exactly which compound you extracted from the ink, is there a list of compounds known to be contained by the ink from which you could narrow down your possibilities?
According to Derby (2014), the chemicals found in cephalopod ink can actually depend on the method used to collect the ink, as collection may release additional chemicals or damage the chemicals in the ink. I’m not sure how Marky’s collects their cuttlefish ink, so it’d be impossible for me to give you a list of the possible compounds in the ink. However, we know that the main compound is melanin (this is what makes it black), and that cuttlefish ink may also contain dopamine, taurine, epinephrine, and numerous proteins.
Well done! You were super well spoken and this was an impressive presentation. I was wondering, if the cuttlefish ink only inhibits growth of bacteria, and it can grow back if provided the nutrients, is this even worth it? Would this be enough to act as an antibiotic or does it need to permanently kill the bacteria?
Awesome question! Both bactericidal and bacteriostatic antibiotics kill bacteria; the difference is the quantity of bacteria that they kill. The former kills virtually the entire bacterial population, while the latter leaves enough bacteria alive for the population to grow back if given nutrients. Thus, both act as an antibiotic. It is “worth it” to discover bacteriostatic compounds because temporarily decreasing the population of bacteria allows the host to recover and fight back: think about it like the difference between your body having to fight a million soldiers, versus one hundred soldiers. Much easier for your immune system to deal with the latter!
Great question! As a general rule of thumb, we can only achieve 10% of any given compound in a person’s blood, so concentrations of 10% and lower are what we call “physiologically relevant” doses; anything above that isn’t really possible in vivo. Otherwise, the efficacy of a drug depends on how each particular organism absorbs, distributes, metabolizes, and excretes the drug. As such, it’s really difficult to determine why a lower dose of a compound can be more effective than a higher dose. As unsatisfying as this answer might be, biology is complicated!
Great job! What specific characteristics of the cuddle fish ink make it act as an antibiotic? Does it target the cell wall perhaps, or inhibit replication?
I wish I could tell you! But we can’t be sure why exactly the cuttlefish ink worked as an antibiotic without knowing the specific compound(s) we extracted from the ink. I can tell you, however, that antibiotics generally kill bacteria through one of the following methods: 1) preventing DNA synthesis, 2) preventing protein synthesis, and 3) disrupting the integrity of the cell wall. As such, the active compound(s) in cuttlefish ink likely work through one of these mechanisms, but if they kill bacteria through a different type of mechanism, that would be super exciting because we would have discovered a new class of antibiotic!
Why do only low levels of cuttlefish ink work better than higher doses? it seems counterintuitive when thinking about concentration and overall strength of the drug.
As I stated in my reply to Adam’s question, we can only usually achieve 10% of any given compound in a person’s blood, so concentrations of above 10% aren’t really viable in vivo. Additionally, each individual organism can absorb, distribute, metabolize, and excrete a drug differently, leading to disparities in the effectiveness of the drug. Otherwise, it might help to remember that we want drugs to be therapeutic: we want to administer just enough of the drug to fix the problem, because the more we go beyond this threshold, the more likely it is for the drug to be lethal to the organism rather than therapeutic.
curesymposium.org 
Although you don’t know exactly which compound you extracted from the ink, is there a list of compounds known to be contained by the ink from which you could narrow down your possibilities?
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According to Derby (2014), the chemicals found in cephalopod ink can actually depend on the method used to collect the ink, as collection may release additional chemicals or damage the chemicals in the ink. I’m not sure how Marky’s collects their cuttlefish ink, so it’d be impossible for me to give you a list of the possible compounds in the ink. However, we know that the main compound is melanin (this is what makes it black), and that cuttlefish ink may also contain dopamine, taurine, epinephrine, and numerous proteins.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4052311/
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Well done! You were super well spoken and this was an impressive presentation. I was wondering, if the cuttlefish ink only inhibits growth of bacteria, and it can grow back if provided the nutrients, is this even worth it? Would this be enough to act as an antibiotic or does it need to permanently kill the bacteria?
LikeLike
Awesome question! Both bactericidal and bacteriostatic antibiotics kill bacteria; the difference is the quantity of bacteria that they kill. The former kills virtually the entire bacterial population, while the latter leaves enough bacteria alive for the population to grow back if given nutrients. Thus, both act as an antibiotic. It is “worth it” to discover bacteriostatic compounds because temporarily decreasing the population of bacteria allows the host to recover and fight back: think about it like the difference between your body having to fight a million soldiers, versus one hundred soldiers. Much easier for your immune system to deal with the latter!
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Do you have any idea why only lower doses of cuttlefish ink appeared to be antibiotic?
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Great question! As a general rule of thumb, we can only achieve 10% of any given compound in a person’s blood, so concentrations of 10% and lower are what we call “physiologically relevant” doses; anything above that isn’t really possible in vivo. Otherwise, the efficacy of a drug depends on how each particular organism absorbs, distributes, metabolizes, and excretes the drug. As such, it’s really difficult to determine why a lower dose of a compound can be more effective than a higher dose. As unsatisfying as this answer might be, biology is complicated!
LikeLike
Great job! What specific characteristics of the cuddle fish ink make it act as an antibiotic? Does it target the cell wall perhaps, or inhibit replication?
LikeLike
I wish I could tell you! But we can’t be sure why exactly the cuttlefish ink worked as an antibiotic without knowing the specific compound(s) we extracted from the ink. I can tell you, however, that antibiotics generally kill bacteria through one of the following methods: 1) preventing DNA synthesis, 2) preventing protein synthesis, and 3) disrupting the integrity of the cell wall. As such, the active compound(s) in cuttlefish ink likely work through one of these mechanisms, but if they kill bacteria through a different type of mechanism, that would be super exciting because we would have discovered a new class of antibiotic!
LikeLike
Why do only low levels of cuttlefish ink work better than higher doses? it seems counterintuitive when thinking about concentration and overall strength of the drug.
LikeLike
As I stated in my reply to Adam’s question, we can only usually achieve 10% of any given compound in a person’s blood, so concentrations of above 10% aren’t really viable in vivo. Additionally, each individual organism can absorb, distribute, metabolize, and excrete a drug differently, leading to disparities in the effectiveness of the drug. Otherwise, it might help to remember that we want drugs to be therapeutic: we want to administer just enough of the drug to fix the problem, because the more we go beyond this threshold, the more likely it is for the drug to be lethal to the organism rather than therapeutic.
LikeLike