All it takes is a pinch on the leg from a sting or bite, and we could be dead within few minutes. Among all the organisms present across the globe, poisonous organisms are present in every taxon. A large number of poisonous species belong to Animalia. Both vertebrates (fishes, amphibians, reptiles, birds, and mammals) and invertebrates( coelenterates, worms, arthropods, molluscs, echinoderms) may be poisonous. Venom from either of these organisms are potent and cause painful effects. Venoms contain many bioactive elements that interact with each other inevitably producing its toxic effects. Despite its dreadful effects, venoms have proved to be a boon for human benefits.
Venom is any poisonous compound secreted by animals to defend itself or harm its prey. Venoms usually serve two functions: defensive,i.e, pain-producing and feeding,i.e, paralysing its prey.
Venoms contain a mixture of ingredients which includes proteins, peptides and non-peptide small molecules. The best-known venoms of invertebrates are complex mixtures of pharmacologically active substances.
Animal venoms can significantly cause dysfunction of the central nervous system, cardiovascular system and muscular system.
Tertiary amines, such as 5- hydroxytryptamine( serotonin, 5-HT), histamine, may occur together with choline esters or tetramethylammonium hydroxide(tetramine).
Kinins and other active peptides may be present. The truly toxic nature of paralyzing factors in invertebrates have been shown by proteins. These proteins are without enzyme activity(neurotoxin, disintegrin, etc)and peptides.
Peptide toxins usually act on the ion channels(e.g ion channel blockers). These peptide toxins are widely present in the venoms of spider, scorpion, cone snail, Elapidae snake.
Venom also contains many enzymes like phospholipases, proteases, oxidases, etc.
HEALING PROPERTIES OF VENOMS
The exact date of using venoms for therapeutic purposes is not known but it was used in ancient Rome for treatment of leprosy, smallpox, fever as well as for healing wounds. Many doctors and researchers have written many articles on the healing properties of venoms.
Greek physician Nicander of Colophon described the action of venoms and the composition of antidotes. The real use of snake venom began when French scientist Albert Calmette found that if venoms are injected in small doses, their blood serum becomes a strong antidote.
The uses of venom were expanded after it was seen that venom from rattlesnake helps to prevent seizures in epilepsy. In 1934, small doses of cobra’s venom were used in analgesic activity. In the analgesic activity, it proved better than morphine since it did not cause any drug addiction. Now venoms are largely used in the treatment of asthma, hypertension and even leprosy.
Captopril emulates the function of the toxin found in Brazilian pitviper (Bothrops jararaca) venom and is generally accepted as the first venom “success” story. Captopril acts as an ACE inhibitor and lowers blood pressure by inhibiting the production of Angiotensin II. Many analogues were produced after the production of Captopril. These are enalapril, Lisinopril, perindopril, ramipril.
Ziconotide is produced from cone snail. It is used in the treatment of severe pain and it is delivered into the body by its infusion in the cerebrospinal fluid using an intrathecal pump system. Ziconotide acts presynaptically on N-type calcium channels, blocking receptors on this channel with high selectivity and specificity.
It is made using the venom of southeastern pygmyrattlesnake and helps in anticoagulation therapies in the effort to reduce the risks of a heart attack.
Exenatide is s 39-amino acid peptide that is a synthetic version of exendin-4, a hormone found in the saliva of Gila monster. It is in use to treat type II Diabetes.
Two venomous species of pit viper are found in South America. One is Bothrops atrox and the other is Bothrops moojeni. Batroxobin from B atrops is used as a drug called reptilase. It is used to stop bleeding while Batroxobin from B moojeni is used for breaking up blood clots.
Venom from a rattlesnake is used in controlling the uncontrolled growth of tumour cells. The venom of the rattlesnake contains a chemical known as crotoxin. Usually, crotoxin is toxic to normal cells but only works on few particular cells. Eventually CB24, cancer treatment was engineered which targets and kills tumour cells. Despite its usefulness, it is not yet commercially available.
▪ Pain Killers
Our body feels pain when cells in our CNS receive pain signals through specific pathways in the cell membrane called sodium channels. While some pain targets to block many sodium channels and thus paralyzing the whole body.
Whereas the venoms from spiders like Mexican red knee tarantula( Brachypelma smithi) blocks fewer sodium channels but also dampens the pain effectively.
▪ DETECT EXPLOSIVES
A few years ago scientists from MIT have developed a new technique for detecting explosives. It uses the venom of the bee by detecting explosives molecules using carbon nanotubes coated with the peptide of the bee’s venom.