What Are the Uses of Snake Venom? A Comprehensive Analysis of Its Main Application Value
1. What Are the Properties of Snake Venom?
Snake venom is a toxic protein and polypeptide substance containing various enzymes secreted by venomous snakes, and it is also the substance that causes poisoning reactions after a venomous snake bite. Fresh snake venom is a somewhat fishy-smelling, egg-white-like viscous liquid, appearing yellow, pale yellow, green, or even colorless. When fresh, it shows a neutral or weakly acidic reaction, and after standing for a while it can become alkaline. Its water content is 50%-75%, and its specific gravity is between 1.030 and 1.080. Fresh venom easily forms foam when exposed to air, and at room temperature it is prone to spoilage and deterioration after 24 hours, losing its toxicity. It can be kept for 15-30 days in a refrigerator, and for a longer time at 40°C. After vacuum drying or freeze-drying, snake venom can be stored at room temperature for 20-30 years, but its toxicity intensity and the activity of some enzymes will decrease to varying degrees, and it can still dissolve in water. The toxicity of snake venom disappears after exposure to ultraviolet light and heating. Strong acids, strong bases, and heavy metal salts that can precipitate and denature proteins can all destroy snake venom. Snake venom is also easily decomposed and destroyed by oxidizing agents, reducing agents, proteolytic enzymes, and the like, thereby losing its toxicity. After treatment with formaldehyde, it also loses its toxicity, but the antigen can still be retained.
2. What Components Does Snake Venom Contain?
The characteristic of snake venom is its complex composition. The venom secreted by different snake species, subspecies, or even the same species in different seasons still has certain differences in its toxic components. Through isolation and purification of snake venom, the main components currently known include neurotoxins, cardiotoxins, coagulation toxins, hemorrhagic toxins, and enzymes. In addition, it also contains some small-molecule peptides, amino acids, carbohydrates, lipids, nucleosides, biogenic amines, and metal ions; some of these have biological activity or are related to biological activity to some extent. After purification, the toxic components of snake venom can be 5-20 times more potent than crude venom, and the toxic components also differ from one another.
3. What Medicinal Value Does Snake Venom Have?
Snake venom has very high medicinal value. Pharmacological studies have shown that snake venom contains pharmacologically active components with procoagulant, fibrinolytic, anticancer, and analgesic effects. It can prevent and treat stroke and the formation of cerebral thrombosis, and can also treat conditions such as thromboangiitis obliterans, coronary heart disease, multiple arteritis, acral arterial spasm, and retinal artery and vein obstruction. Snake venom also has a certain effect on alleviating the symptoms of patients with advanced cancer, especially its analgesic effect, which has attracted worldwide attention. Snake venom is made into various antivenoms for treating bites from various venomous snakes, with remarkably rapid curative effects, and has now been widely promoted.
4. What Clinical Applications Does Snake Venom Have?
Our country has made rapid progress in snake venom research and clinical application. A large amount of clinical practice has proven that snake venom has the following clinical applications.
(1) Analgesic effect As early as the 1970s, a cobra venom injection developed by Guangzhou Medical College was used clinically and had good effects on diseases with pain as the main symptom, such as trigeminal neuralgia, sciatica, malignant tumor pain, rheumatic and rheumatoid joint pain, migraine, and herpes zoster. As an analgesic, snake venom has the following advantages: significant and long-lasting effects, a wide safety range, and no drug resistance after continuous use. Unlike morphine, it does not give a feeling of addiction or carry that danger. Ketongling, successfully trial-produced from cobra venom by the Kunming Institute of Zoology in 1976, has very good efficacy in treating various painful diseases.
(2) Lowering blood pressure Foreign reports say that an active peptide isolated from the venom of the Brazilian pit viper can block the conversion of angiotensin, thereby reducing the pressor activity of angiotensin in the human body, and can be used to prevent and treat renal hypertension and blood pressure elevation caused by prolonged compression of the renal artery. Our country has also discovered components in the venom of the five-paced pit viper with very obvious blood pressure-lowering activity, which can be developed into a new antihypertensive drug.
(3) Hemostatic effect Viper venom can turn fibrinogen in the blood into fibrin to form blood clots, and a 0.1% sterile solution of viper venom can be used to treat bleeding in hemophilia and other conditions. In addition, it can also be used for the differential diagnosis of blood diseases, becoming one of the clinical testing methods.
(4) Anticancer effect The General Hospital of the Shenyang Military Region used pit viper venom in combination with chemotherapy to treat patients with osteosarcoma, significantly prolonging the patients' survival time. In recent years, the Xindong Subdistrict Hospital in Changning District, Shanghai, has used snake venom capsules to treat various cancers, with effects such as shrinking tumors and prolonging the survival period of cancer patients. China Medical University has carried out research on the inhibition of tumors by the crude venom and isolated venom of the Shedao pit viper, and the results showed an anticancer rate of 30%-87.1%. In addition, the PLA 238 Hospital's Army-wide Snake Venom Clinical Application Research Center has completed the extraction and isolation of anticancer and tumor-inhibiting components from snake venom and entered the animal experiment and clinical stages.
(5) Treatment of cerebral thrombosis and vasculitis The PLA 238 Hospital used the venom of the Changbai Mountain white-eyebrowed pit viper, purified at high temperature, to obtain a thrombin-like enzyme pharmaceutically named "Qingshuanmei," which contains no toxic components and is used to treat cerebral thrombosis and its sequelae. Clinical evidence shows that this enzyme is safe and reliable, with very good efficacy. For patients with vasculitis, it can rapidly relieve pain and promote appetite and sleep. Some patients with hemiplegia caused by cerebral thrombosis even recovered as a result.
(6) Treatment of gastric and duodenal ulcers The research office of China Medical University used venomous snakes to treat 6 cases of gastric and duodenal ulcers. After barium meal and gastroscopy re-examination, with only 30 days of medication, 5 cases were completely cured and 1 case showed ulcer shrinkage. Clinical practice has also proven that the use of snake venom to treat digestive tract ulcers has the effects of relieving pain and promoting sleep, and has the advantages of increasing patients' appetite and body weight, and is well worth promoting.
(7) Preparation of antivenom Our country began producing antivenom in the 1930s and successively succeeded in developing refined antivenoms against pit viper, five-paced pit viper, many-banded krait, cobra, **pit viper, sea snake, banded krait, viper, and other venomous snakes, making great contributions to saving people bitten by venomous snakes.
(8) Snake venom is also used in drug rehabilitation and the military field Research institutions in the United States have already engaged in research in this area.
5. Which Domestic Institutions Are Carrying Out Research on the Medicinal Use of Snake Venom?
With the development of human society, research on snake venom has flourished. At present, the research topics of China's medical circles and biologists mainly fall into three research areas: first, the application of antivenom; second, the chemical components of snake venom and its toxicological and pharmacological effects; third, the clinical application of snake venom. The institutions engaged in this research include: China Medical University, the Shanghai Institute of Materia Medica under the Ministry of Health, Zhejiang Medical University, Guangxi Medical College, Zhongshan Medical College, the Chinese People's Liberation Army 238 Hospital, Shenyang Pharmaceutical University, the **Branch of the Chinese Academy of Sciences, the Zhejiang Institute of Traditional Chinese Medicine, the Kunming Institute of Zoology of the Chinese Academy of Sciences, Taiwan University, Taiwan Tsinghua University, and others.