What is the most poisonous snake in the world? The primacy goes to the taipan of the hinterland, an Australian snake, but to chase him at a very short distance there are the Mamba, first of all the black mamba, also known as “snake of the seven steps” in reference to the time that passes between a bite and death.
Well, precisely the poison of black mamba – together with that of his tight relatives, the western green mamba and the green mamba of Jameson – is the protagonist of a study by the University of Queensland which reveals why it is so lethal: it has an “extra” effect, which also manages to combat antidotes. The study is published in the magazine Toxins.
100%lethal. The poison of black mamba is largely composed of neurotoxins (including the dendrotoxins, which prevent the nervous impulses from transmitting), and 10 milligrams are enough to kill an adult man – considering that a bite injury on average 100, you will understand why the bite of the mamba has a 100% lethality rate unless you immediately intervene with an antidote.
Two types of paralysis. The first symptom of the bite of Mamba is a form of paralysis known as flaccid paralysis, in which as the name suggests the muscles weaken and lose the ability to respond to nerve stimuli. There are four species of mamba, and three of these cause flaccid paralysis: the exception is the oriental green mamba, which instead causes spastic paralysis, characterized by uncontrolled movements of the muscles.
Well, the study of the University of Queensland shows that the other three Mamba also cause this type of paralysis.
The limits of antidotes. When using the antidote to the bite of Mamba, the flaccid paralysis disappears, but the toxins injected by the bite go to that point to attack another part of the nervous system, causing spasms and involuntary contractions. It is a secondary effect that was already known at a anecdotal level (people who are treated with the antidote, seem to feel good and then begin to have uncontrolled and painful spasms), and which is now also confirmed experimentally.
What do we need to know? The authors of the study describe this phenomenon as follows: “It is like treating a disease and this suddenly shows another”. This is because the poison acts in two ways: first blocks the nerve signals, then, in front of the antidote, passes to the opposite extreme, overestimating the muscles. In short: current antidotes have limits, and this study helps to identify them and understand why certain unexpected reactions.
Considering that the mamba make about 30,000 victims a year in sub-Saharan Africa, it is an essential discovery.
