Sweating is a pretty gross nuisance. However, we cannot complain. After all, it is the way we have to cool our body. The perfect combo would be if, in addition to keeping us cool, the sweat served us as sunscreen. But we can’t be that cool, basically because we’re not hippos.
And yes, oddly enough, these animals sweat their own sunscreen. But it is also that, if all that were not enough, it also serves as a antibiotic.
It is clear that human beings are too far from reaching these levels of sophistication. We only have to study them, with the aim of trying to take them as an idea. In fact, this is precisely what a team of japanese researcherswhose results were published in Nature.
How does a sunscreen work?
The sunscreen that we humans usually use can be of two types: or physical or chemical. Physical filters are those that act as a shield, reflecting solar radiation so that they do not penetrate the cells of our skin.
Instead, chemicals do not reflect them, but they absorb them. In any case, the result is just as good, since, by absorbing them, they also do not allow them to reach the cells and can damage DNA.
It is true that humans also have a natural sunscreen: the melanin. This is a pigment that acts in a similar way to how the chemical filters, since it is generated in response to sun exposure and is responsible for absorbing radiation. However, if we do not put sunscreen on top, it is of little use, since the synthesis of pigment is not enough to deal with solar radiation. Instead, hippos protect themselves quite well with their sweat. But how exactly does this work?
The secret of hippo sweat
For years, scientists have seen that hippos’ sweat, initially similar to our own, changes color over time, becoming reddish brown.
This has led to the suspicion that it could have multiple applications for these animals. However, until these Japanese scientists investigated it, was not known for sure.
When analyzing sweat samples, they found that this color change is produced by the presence of non-benzenoid aromatic compoundswhich are unexpectedly acidic and have antibiotic and sun protection activity.
The protective effect would be similar to that exerted on our skin by chemical filters or melanin itself. It is quite effective, as when it dries on the skin keeps its color for several hours. Afterwards, it ends up polymerizing into a brown solid.
As for the antibiotic role, it was discovered by putting sweat samples in contact with different populations of bacteria. They found that, at concentrations lower than those found in hippos, these substances can inhibit the growth of pathogenic bacteria, such as Pseudomonas aeruginosa Y Klebsiella pneumoniae. These are also dangerous for humans. For this reason, we cannot rule out its possible efficacy in the search for new bactericides to combat antibiotic resistant bacteria.
But putting aside their possible effect on humans, what is clear is that they play a key role in the rapid hippopotamus wound healing. When these animals have an injury, despite being in contact with mud and other places where pathogenic microbes may be, they overcome possible infections simply thanks to their sweat. Without a doubt, if for us sweating is a blessing that keeps us a little cooler, for them it is a panacea. So that later they say that they are not interesting animals.