Snake venom is both a deadly poison and a life-saving medicine | Talking about snakes in the Year of the Snake

This year is the Year of the Snake in the Chinese Zodiac. In different cultures, snakes are symbols of death and danger, but they also represent wisdom and rebirth. This duality reflects the profound connection between nature and human civilization: many venomous snakes are highly lethal, but scientists have discovered that their venom is also a good medicine for treating diseases. Nature's "death weapons" are transforming into life-saving medical miracles.

Written by | Pikachu Bulbasaur

2025 Year of the Snake Welcomes the New Year | Image source: Generated by GPT4

In many ancient legends and the Chinese zodiac culture, snakes symbolize wisdom and power, but also danger and mystery, and this duality is also reflected in their "venom". From ancient herbal medicine to modern laboratories, scientists have discovered that snake venom is not only a "weapon" for snake hunting, but also a valuable resource in nature. It is precise and powerful, and has now become an important source for the development of new drugs. Through the power of science, snake venom is being transformed from a "lethal weapon" to a "healing medicine". In this Year of the Snake, let us explore the mysteries of snake venom and see how it saves lives.

The Nature of Snake Venom

Snake venom is a unique "biological weapon" formed during the long evolution of snakes. Venom is secreted by venom glands on both sides of the snake's head and ejected from fangs connected to the ducts through muscle squeezing. Its chemical composition is extremely complex, mainly composed of enzymes, proteins and peptides, and each molecule has a specific "killing task". These molecules work together to make the venom act quickly and fatally in the prey's body. Different snake venoms can cause different "deaths" for prey, including "neurotoxins" that interfere with the transmission of prey nerve signals, causing paralysis or respiratory failure, hemolytic toxins that destroy blood cells and blood vessel walls, causing internal bleeding or organ failure, cytotoxins that directly cause cell lysis or necrosis, and mixed toxins that have several effects and are "super-doubled".

A venomous snake spraying venom (left) and the general structure of the venom gland (right)

The lethality of snake venom comes from its highly precise mechanism of action. Each snake's venom has a different effect on the human body, but the common feature of them is that they are extremely potent. Take the cobra, for example. Its venom is rich in neurotoxins, which can bind to receptors on the surface of nerve cells and prevent the normal transmission of nerve signals. Neurotoxins can be likened to "breakers". They cut off the connection between nerves and muscles, making muscles unresponsive, especially respiratory muscles. If a person is unfortunately poisoned, the body will not be able to breathe normally and will eventually die from respiratory failure. The precision and lethality of this mechanism are chilling.

In contrast, rattlesnake venom destroys the coagulation factors and platelets in the blood, causing the blood to be unable to coagulate. Under normal circumstances, the blood will quickly coagulate at the wound to prevent excessive bleeding. However, under the effect of rattlesnake venom, the blood will become unable to stop bleeding, the wound will continue to bleed, and eventually it may be fatal due to excessive blood loss. This situation is like a leaking water bag, the water keeps flowing out, and it cannot be stored and preserved until the water source is exhausted.

The venom of some snake species is more complex, such as the mixed venom of cobras and rattlesnakes, which combines multiple components such as neurotoxins, blood toxins and hemolytic toxins. This multiple lethal effects of snake venom show that its attack on the human body is not only rapid but also extensive, and can cause damage to multiple organs in a very short period of time. Therefore, the study of snake venom, especially deciphering its complex components and mechanisms of action, has become a major challenge in the fields of biology and medicine.

Consequences of different snake bites

The basis for studying and applying snake venom is the collection of venom. In order to collect snake venom, special tools are usually needed. Researchers will carefully press the snake's fangs to force the venom into the container through the venom gland. This process can be said to be a combination of technology and courage. If you are not careful, the venomous snake may suddenly fight back during the "squeezing venom" process and pierce the researcher's arm with its fangs, which may be fatal.

In order to protect venomous snakes, scientists often design reasonable collection plans based on the snakes' venom secretion cycle to avoid excessive interference with their natural lives. For those snake species that need to collect venom regularly, scientists will even set up "venom collection farms." These places look like ordinary snake houses, but are actually important bases for venom research. In these "farms," ​​venomous snakes are carefully cared for and live in conditions close to their natural environment, which can keep them in good condition and provide a steady supply of venom for research.

Collection of snake venom

Snake venom medicine: from disease-causing to disease-curing

Looking back at human history, different cultures have recorded snake venom with awe and curiosity. In the ancient Chinese classic "Compendium of Materia Medica", Li Shizhen recorded the medicinal effects of snake venom in detail and proposed the concept of "fighting poison with poison". In the West, snakes are regarded as symbols of healing and regeneration in Greek mythology. For example, a snake is wrapped around the staff of Asclepius, the god of medicine. This image is now a symbol of global medicine. These legends and symbols not only reveal the status of snakes in the hearts of ancient people, but also convey an important message: although they do not understand the scientific principles of venom, snake venom is not only "poisonous", but also closely related to human health.

As time goes by, human research on snake venom has gradually shifted from empirical to scientific, and the composition and mechanism of action of snake venom have been gradually revealed, opening up new horizons for modern drug development.

Among them, batroxobin is a commonly used hemostatic drug extracted from snake venom. Its discovery and research history can witness the breakthrough of scientific exploration and the deep understanding of the nature of snake venom. In the 1950s, scientists discovered that the venom of the Brazilian dart snake (Bothrops jararaca) has a special blood coagulation effect, which can quickly promote blood coagulation to form blood clots. Further separation and purification found that this enzyme selectively acts on fibrinogen in the blood, converting it into fibrin, thereby accelerating blood coagulation and effectively promoting rapid hemostasis of wounds, but will not cause the formation of abnormal thrombi. The characteristics of this enzyme give it great potential in surgery and trauma treatment. In 1998, Chinese scientists began to try to extract hemocoagulase from the venom of the Chinese native snake species, the sharp-nosed pit viper (Deinagkistrodon acutus). After ten years of hard work, it was officially launched in 2009 (the trade name is "Suling"), becoming China's first snake venom hemocoagulase national class I new drug with independent intellectual property rights. Nowadays, snake hemocoagulase preparations are used prophylactically or therapeutically to reduce bleeding in various surgeries with large trauma and high bleeding risk (such as liver surgery and neurosurgery).

Snake venom has more medicinal value than just stopping bleeding. Considering that the components of snake venom can precisely act on specific targets in the human body - for example, on neurotransmitter receptors, blood coagulation factors or muscle cell surface receptors, this "precision strike" feature makes snake venom a natural template for the development of many drugs. For example, in the 1960s, scientists extracted a bradykinin from the venom of the Brazilian dart snake mentioned above. This component can inhibit angiotensin-converting enzyme (ACE) in the human body, thereby effectively lowering blood pressure. This discovery directly led to the birth of the antihypertensive drug Captopril, which became the world's first ACE inhibitor antihypertensive drug and is widely used in the treatment of cardiovascular diseases.

There are also some hemolytic toxins in snake venom that can effectively inhibit blood coagulation. After scientists modified this property, they developed the anticoagulant drug argatroban, which is used to treat thrombosis and other coagulation-related diseases; similar products include the development of analgesics and anticoagulants. What is even more surprising is that in recent years, the venom components of some venomous snakes have been found to have the ability to inhibit the growth of tumor cells. For example, the toxin extracted from the venom of the Southeast Asian cobra can selectively attack cancer cells without affecting healthy cells. This property has also brought new research directions for cancer treatment.

The line between safety and danger

Snake venom, as the ultimate "weapon" evolved in nature, is designed for fast, accurate, and ruthless killing. It makes people feel awe and curiosity: Why can snake bites be fatal, but snake venom can be used to develop drugs to treat diseases? The core concept of drugs is "targeted", that is, to act on specific molecules or cells in the diseased area. When scientists began to study snake venom, the first thing they noticed was its "precision attack" targeting, which makes snake venom an ideal template for drug development.

However, the research and development of snake venom is not always smooth sailing. The scarcity of venom sources, the removal of toxic components, and the control of drug side effects are all challenges faced by the scientific community. Human creativity has transformed snake venom from a "killer" to a "savior", writing a wonderful chapter between "poison and medicine", and reminding us that every substance in nature may contain infinite possibilities.

In this special year of the Snake, let us re-examine the dual face of snake venom. It is both a biological weapon of nature and a key to healing in modern medicine. In the future, with the continuous advancement of science and technology, the potential of snake venom will continue to be explored, providing more solutions for human health. Snake venom will continue to write its never-ending legendary story, allowing science and nature to dance together.

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