Snake venom: Nature's optimal weapon

Snake venom is a deadly weapon, formed over a period of over 100 million years. It kills tens of thousands of people every year. And thanks to new research, it can be the foundation of new therapies that save lives.

As a predator, snakes lack important features. They have no legs to chase prey, no claws to knock down and pinch their prey. But these shortcomings are unharmed because evolution has given snakes an optimal weapon: Venom. With this weapon, several hundred species of venomous snakes can kill and weaken prey before they can escape.

The venom has turned snakes into a small but effective predator, and they are everywhere - as long as the environment is warm enough for them to move. Snakes live anywhere from tree tops to dense forests, in the desert and in the sea.

Snakes cross poisonous newts in the evolutionary race

In general, scientists agree on how poisonous glands evolve, but the poison itself is another case. Some scientists argue that venom is composed of modified proteins from solid saliva, which functions to break down and digest prey. Others believe that the ability to produce toxins evolved independently in different snakes.

But Australian researcher Bryan Fry, one of the world's leading experts in venomous snakes, has another theory. With the help of DNA analysis, he discovered most of the proteins and enzymes found in venom are quite close to those found in other parts of the solid body - for example, in the liver, muscle Gastrointestinal or other systems. The controlling gene produces these substances in parts, in a way, activated in the snake's salivary glands, where they produce substances once modified and modified that can help the snake Kill prey extremely effectively.

Fry also believed that this ability occurred at a certain time, 100 million years ago in one of the earliest ancestors of modern snakes. It then appeared in all snakes, but was only developed and modified in the three snake families that we now consider toxic. Snake venom, in other words, is older than the snake itself.

Snake venom robs tens of thousands of people every year.And thanks to new research, it can be the foundation of new therapies that save lives.(Photo: Robert Valentic / Nature PL)

Three types of venom

Snake venom is distinctly different from species to species, but they all have one thing in common: each of them are extremely complex compounds, formed from thousands of different proteins and enzymes, each re-type has a separate function.

The venom can generally be classified into three main groups: cytotoxins, neurotoxins and hemotoxins . But the boundaries of the three groups are quite fuzzy, most species use a combination of 3.

The type of poison and the speed of damage are formed in accordance with the life of the snake and its prey. For example, sea snakes have extremely fast venom, they like to live around coral reefs and their most important prey is fish. If the fish does not die immediately, sea snakes are at risk of losing their meals.

Other species that live in environments do not care whether the prey can move a bit before dying. After the snake attacks, it lets the prey escape. Physical activity will ensure that the venom is spread quickly in the prey. The snake then uses the ability to sniff to track the prey. Another guaranteed characteristic is that some of the toxins contain powerful diuretics, which cause the prey to urinate on the escape route. So snakes will find them easier.

Many snakes produce a small amount of weak poison just enough for their small prey. But many other venom types are extremely dangerous for large animals - including humans. This is certainly the case of the king cobra, the world's most poisonous snake, which can take down an elephant with a bite. King cobra can also hunt other snakes, which have formed resistance to snake venom. And that's the reason for this powerful poison: It takes more venom to kill a snake than a mammal.

Be careful when you hear the tail-ringing of the American rattlesnake.Their venom has extremely strong cytotoxin.(Photos: Mongabay)

Complex poisonous routes deadly

All poisonous snakes have specially modified teeth that can be actively injected into their prey, but their diversity is amazing. Most venomous snakes are divided into 3 families: Colubridae, Elapidae or Viperidae and different injection systems of poison in each type. The most primitive fangs are found in water snakes - for example, African dry snakes. Their fangs are located just behind the mouth and are often very short. This means they have to get their prey into their mouth and start chewing before releasing the poison.

In the elapid group, including cobra, the front teeth have developed into fangs. But the most developed system is the viper snake group, a solid group including the American bell tail.

In the viper group, the canine teeth in the upper jaw have been transformed into a complex syringe. When the snake's mouth is closed, it lies backwards on the lower palate, but will pop out when the snake is hunting. And when they plug into prey, the venom bounces off the salivary glands through hollow fangs and enters the prey.

Designing canines is just one of many factors that determine the danger of snakes to humans. Even the compounds and venom of venom are not always the deciding factor - this is why the list of the most venomous snakes in the world does not always reflect reality. The life of snakes and their temperament are equally important.

For example, sea snakes are thought to have the most toxic venom of snakes, but they only produce small quantities. Although many people are bitten by them, only a few people lose their lives. They are not aggressive unless threatened, so they are not particularly dangerous. However, the African snake-snake species has a moderate toxicity but they produce large amounts and have particularly large and long canines. Considering all the factors, they are far more dangerous than sea snakes.

The African obese snake has a bite that causes the prey's blood to clot and they will die because of the blockage of blood.(Photo: Kostich.com)

Treatment

It is hard to believe that substances that were born to kill are likely to become useful drugs. But this is true. The first drug isolated from the snake's venom is the Brazilian viper snake, Bothrops jararaca, 1949. This toxin dilates blood vessels, causing prey to lower blood pressure so they react more slowly and eventually. depressed. The poison then becomes the foundation for a common family blood pressure medication called ACE inhibitor.

Another effective drug for treating blood disorders from Malaysian viper snakes. In its pure form, toxins cause prey to die from massive hemorrhage by preventing blood clots. For humans, this substance is used to treat blockages of blood.

Snake venom usually has an effect on certain cells, and this characteristic leads to an important study of cancer treatments. Typical chemotherapy drugs cause side effects because they cannot distinguish between cancer cells and the body's healthy cells. Some works are testing the use of snake venom to destroy only blood vessels that carry nutrients to the tumor, thereby starving it to death.

Unfortunately, converting snake venom into medicine can be very time consuming because they contain too many different ingredients. In many cases, a snake's venom can cause many opposite effects.

For example, from the Siberian cobra venom, scientists isolated three types of enzymes phospholipases, which have identical chemical composition but differ in acidity, but they have completely opposite effects. Low-concentration phospholipases inhibit blood clotting while high-concentration phospholipases destroy red blood cells. The middle type is neurotoxin.

Many types of neurotoxins work by restraining or completely blocking neural activity, so there are quite interesting studies aimed at diseases such as epilepsy with many electroencephalic activities, treating pain or help people addicted to quit smoking. Remarkably, other substances that have just been discovered in snake venom actually nourish the formation of new neuron cells. This will be useful for people with Alzheimer's disease and other diseases that neurons in the brain die.

Snakes can kill tens of thousands of people every year but its deadly venom has the potential to cure thousands of others.