Poisoning snake venom

Poisonous snake venom contains phospholipases that hydrolyze phospholipids in red blood cells. 

Other Lethal Agents. There are a number of substances, many found in nature, which are known to be more toxic than nerve agents (6). None has been weaponized. Examples of these toxic natural products include shellfish poison, isolated from toxic clams puffer fish poison, isolated from the viscera of the puffer fish the active principle of curare "heart poisons" of the digitaUs type the active principle of the sea cucumber active principles of snake venom and the protein ricin, obtained from castor beans (See Castor oil). 

The venoms of poisonous snakes contain (among other things) a class of enzymes known as phospholipases, enzymes that cause the breakdown of phospholipids. For example, the venoms of the eastern diamondback rattlesnake (Crotalus adamanteus) and the Indian cobra Naja naja) both contain phospholipase Ag, which catalyzes the hydrolysis of fatty acids at the C-2 position of glyc-erophospholipids. 

All sea snakes are poisonous and their venoms are extremely toxic. The LD q for crude sea snake venom can be as low as 0.10 fig/g mouse body weight (i). For purified toxin the LD q is even lower, suggesting the high toxicity of sea snake toxins and venoms. This toxicity is derived from the presence of potent neurotoxins. Compared to snake venoms of terrestrial origin, sea snake venoms have been studied less. Different enzymes reported to be present or absent are summarized in Table I. 

A. indica L. Indian Aristolochia, also known as Indian birthwort, ishvara (Sanskrit), or adagam (Tamil), is a bitter climber native to India. The medicinal material consists of the rhizome, which is to resolve inflammation (India), counteract insect poison, and as an antipyretic (Philippines and Vietnam). The rhizome contains aristolochic acid, which inhibits in vitro and dose-dependent phospholipid hydrolysis by the human synovial fluid phospholipase A2, snake venom phospholipase A2, porcine pancreatic phospholipase A2, and human platelet phospholipase A2 (2). 

Some naturally occurring extremely toxic and supertoxic chemicals are listed in Table 4.2, along with their environmental sources and toxicity targets. Some of these are toxins found in the venom of poisonous snakes or in the tissues of certain species of... 

Williams, B. L., Brodie, E. D., Jr., and Brodie E. D., Ill (2004). A resistant predator and its toxic prey persistence of newt toxin leads to poisonous (not venomous) snakes. Journal of Chemical Ecology 30,1901-1919. 

Snake venom antisera Horse Antibodies raised against venom of various poisonous snakes... 

In the UK, the adder (Vipera berus) represents the only indigenous poisonous snake and adder antivenin preparations are termed Zagreb antisera . European viper venom antisera contain antibodies capable of neutralizing the venoms of one or more species of viper Vipera ammodytes, V. aspis, V. berus and V. ursinii). In many instances, antivenin preparations are polyvalent in nature. This is particularly helpful in cases where the victims are unsure of which snake actually bit them. 

Use of Toxin Binding to Purify a Channel Protein a-Bungarotoxin is a powerful neurotoxin found in the venom of a poisonous snake (Bungarus multicinctus). It binds with high specificity to the nicotinic acetylcholine receptor (AChR) protein and prevents the ion channel from opening. This interaction was used to purify AChR from the electric organ of torpedo fish. 

In a typical year there are some 45,000 snake bites in North America alone, but only 20 per cent of these are from poisonous snakes and only a proportion of these involve toxin or venom. This still leaves over 1,000 poisonous snake bites in which venom is injected, but deaths number only a handful, perhaps twelve to fifteen. The reason for this is that medical care is normally not too far away and the antidote or antivenin is available. Without treatment, for example, approximately 75 per cent of rattlesnake bites would be fatal. Similarly, in Australia, which has some of the world s most poisonous snakes, death from snake bite is rare because... 

The venom of poisonous snakes contains a class of enzymes known as phospholipases. These enzymes catalyze the breakdown of phospholipids, triglycerides in which one fatty acid has been replaced by a phosphate group. The venom of the eastern dia-mondback rattlesnake contains a phospholipase that hydrolyzes the ester bond at the middle carbon of phospholipids, if the larger of the two breakdown products of this reaction gets into the bloodstream, it dissolves the membranes of red blood cells, causing them to rupture. A bite from the eastern diamondback can lead to death if not treated immediately. 

See also Animals, Poisonous and Venomous Snake, Elapidae Snakes. 

Russell FE (1983) Snake Venom Poisoning. New York Scholium International, Inc. New York. 

Black Widow spider venom contains several different protein fractions. The most significant component of the venom is the neurotoxin, a-latrotoxin. This neurotoxin acts at the presynaptic membrane of the neuronal and the neuromuscular junctions. The binding of the a-latrotoxin results in the opening of nonspecific cation channels, a massive influx of calcium, release of acetylcholine and norepinephrine and decreased uptake of the neurotransmitter. The neurotransmitter release is most likely responsible for hypertension, muscle fasciculations, and spasms frequently experienced by victims of a bite. Later, generalized muscle weakness and labored breathing may develop in severe cases. While the venom of the black widow spider has been characterized as being more potent than that of many poisonous snakes, the small amount of venom injected limits the degree of toxicity. 

Snake Venom Poisoning, Second Edition Eindlay E. Russell Scholium International, Great Neck, New York, 1983. 

A few extremely toxic and supertoxic chemicals are listed in Table 2, along with their environmental sources and toxicity targets. Some of these are toxins found in the venoms of poisonous snakes or in the tissues of certain species of animals. Dr. Findlay Russell, who has made enormous contributions to our understanding of the nature of animal toxins, their modes of biological action, and the procedures for treating people who have been envenomed or poisoned, estimates that there are about 1200 known species of poisonous or venomous marine animals, countless numbers of venomous arthropods (spiders), and about 375 species of dangerous snakes (out of a total of about 3500 species). 

All of these compounds fit our definition of drugs. It may seem strange to include poisons and snake venoms as drugs, but they too react with a biological system and produce a biological response—a bit extreme perhaps, but a response all the same. 

One of the earliest examples of chemical warfare was in the late Stone Age (10,000 BCE). Hunters known as the San, in southern Africa, used poison arrows. They dipped the wood, bone, and stone tips of their arrows in poisons obtained from scorpion and snake venoms, as well as poisonous plants (CBW Info, 2005 Tagate, 2006 Wikipedia, 2007a). 

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