Venom is one of Nature’s unexplored treasure chests of medicine. Hard to believe, it is strange but true. Scientists have discovered that natural poisons, toxins and venoms contain chemicals that can be used to create an array of drugs for treating everything from chronic pain to cancer. For instance, the cone shell’s venom, packed with nerve-debilitating conotoxins, provides the basis for a new painkiller. Contortrostatin, a component found in copperhead venom, is being used to attack breast cancer cells and to prevent cancer from spreading.

Today’s cutting edge research on different venom is showing that diabetes, coronary heart conditions, and cancer might be cured or slowed down from venom derivatives. Many research activities involving various venoms have proven worthy of the effort. The venom of spiders, snakes, scorpions, lizards and snails, to name just a few creatures, are providing important ingredients and knowledge for the development of many medicines. Call it the poison paradox — or The Venom Cure.

What do venoms and medicines have in common? Both alter biological functions and affect physiological process. This precisely is the reason that venom is of interest to medical researchers. What are venoms made of? Most venom are complex molecules and may be composed of as many as a hundred different peptides, enzymes and toxins. Most venoms are mostly haemotoxic (toxins that destroy red blood cells) or neurotoxic (neurotoxins alter the normal activity of the nervous system) or a combination of both.

Here is a glimpse into some research work of scientists around the globe involving venom, their findings and the promise it holds.

Cobra Venom for Arthritis

The Indian cobra is one of the most common venomous snakes in South East Asia, and is responsible for most of the 10,000 deaths by snakebite that occur in India each year. India’s traditional medicine system, ayurveda, has used these cobra venoms to treat various health conditions for thousands of years. Physiologist Antony Gomes and his research team at the University of Calcutta in India published a paper in the journal Toxicon in 2010 showing the role that the venom might play in improving arthritis. In the study, male rats were induced with arthritis and were then injected with non lethal doses of Indian monocellate cobra venom. The rats showed significant improvement in their arthritic symptoms.

Some Promising Snake Venom Research

Research conducted at the by R. Manjunatha Kini and his team at the National University of Singapore has found various components from snake venoms with a number of different medical properties which include the ability to prevent blood from coagulating, prevent pain and also fight cancerous tumors. Kini believes that a number of toxins from venoms could help in developing therapeutic agents for the treatment or prevention of human diseases.

In Australia, research at the Queensland Institute of Medical Research has found that a number of snakes generate a highly effective blood - clotting chemical. In nature the venom produced by these snakes clots the blood of their prey within only a few seconds. The potential of these chemicals in stopping blood flow in the wounds of trauma patients or those in surgery is substantial and clinical trials of drugs made with these chemicals have taken place. Though some setbacks have been encountered regarding liver toxicity, effort is still underway to allow use of these chemicals for enhancing blood-clotting ability.

Another promising area of research into snake venom is in the treatment of cancer. Efforts at the Chungbuk National University in Korea have found that some components of snake venom have the ability to cause cell death in prostate and breast cancer cells without significant effects on other healthy cells. Other investigation of snake venom at National Taiwan University has found that some components of venom can prevent spreading cancer cells from adhering to bone and can thus act to limit the ability of these cancers to spread.

Scorpion Venom and Nano-cocktail Target Brain Tumours

Recently, Miqin Zhang, a materials scientist at the University of Washington and her research team showed that a certain compound found in the venom of the deathstalker scorpion could help in the treatment of brain cancer. The deathstalker scorpion, native to North Africa and the Middle East, is highly dangerous because of its venom - a neurotoxin powerful enough to kill a child or elderly person, often by causing pulmonary edema.

In a study published in 2010 in the monthly journal ACS Nano, Zhang showed  a way to use an ingredient of the venom called chlorotoxin to help treat brain cancer. In gene therapy, doctors inject small bits of healthy DNA that are attached to nanoparticles, and these move toward the tumor site to repair or replace the cancer-causing gene mutations. The problem is that many of the substances currently used for delivery either don’t deliver the genes efficiently or have potentially harmful side effects. By attaching chlorotoxin to the nanoparticle, Zhang and her research team managed to get significantly more of the therapeutic DNA sequence into the cancerous cells than by using nanoparticles without the compound.

Scorpion Venom for Studying Pancreatitis

A compound called antarease, similar to the peptide found in tarantula venom, has proved a useful medical tool because of its effect on ion channels. East Carolina’s Fletcher discovered the compound in the venom of the Brazilian yellow scorpion, which often causes pancreatitis - a severe inflammation of the pancreas - in sting victims. Fletcher’s research team found that antarease is the likely cause; when they injected the purified compound into pancreatic tissue, it disrupted the pancreas’ control of its digestive enzymes, insulin, and other proteins, which can cause inflammation.

Pancreatitis is more commonly caused by gallstones and alcohol abuse, and recent studies suggest it may be a precursor to pancreatic cancer. Fletcher hopes to use his work with scorpion venom and antarease to further understand the pathology of pancreatitis and eventually plan a better treatment for it. The findings of his research have been published in the Journal of Biochemistry in March 2010

Bee Venom in Cancer Treatment

In a similar study, Samuel A. Wickline, a biomedical engineer at Washington University School of Medicine in St Louis, altered a protein found in bee venom - which often causes inflammation after stings - called melittin. Like chlorotoxin, melittin can help deliver therapeutic drug compounds to damaged cells. Wickline linked the compound to the membrane of nanoparticles, which, without disrupting a drug’s normal function, helped it more accurately hit its target. Scientists are primarily focused on using this as an anti - cancer therapy. He reported his findings in the Journal of Clinical Investigation in 2009 and in the FASEB Journal in 2010.

Tarantula Venom for Muscle Dystrophy

Frederick Sachs, a biophysicist at the University of Buffalo, studies the function of ion channels on the membranes of muscle cells to see what happens in muscle tissue when you turn these channels on and off. He has been searching for a chemical that would inhibit these channels.

After getting no results from known drug compounds, he and his research team turned to the Chilean rose tarantula, a relatively harmless spider commonly bought in pet stores. In their studies of the venom, which is too weak to harm a human, they came across a peptide that they called GsMtx-4.

Sure enough, the isolated peptide successfully turned the channels off, which Sachs figured could reduce the amount of stress in muscles. Excessive mechanical stress on muscles is common in muscular dystrophy, a disease that can cripple young children. But by injecting a synthetic version of the peptide into lab mice with dystrophy, Sachs found that muscle activity improves. His findings have been published in Nature and Journal of General Physiology. Currently, Sachs and his research team are awaiting FDA approval to begin clinical trials, on the molecule which FDA has classified as an ‘orphan drug therapy’. This status is like a fast - track testing route for drugs.

Gila Monster’s Venom for Diabetes

In the 1990s, scientists studying a southern Utah population of the Gila Monster - a lizard, split apart the compounds of its venom in order to isolate various properties and effects. Of these components, the peptide exendin - 4 was found to moderate glucose levels and stimulate the slow, steady production of insulin, a process that aids digestion. Why? Because although gila monsters don’t eat often, when they do, they gorge on their food.

In 2005, the U.S. Food and Drug Administration approved the drug exenatide, a synthetic version of exendin - 4 (marketed as Byetta) for the management of type 2 diabetes. In a three - year study with people with type 2 diabetes, exenatide led to healthy sustained glucose levels and progressive weight loss. The effectiveness is due to the fact that the lizard protein is about 50 percent identical to glucagon - like peptide - 1 analog (GLP - 1), a hormone released from the human digestive tract that helps to regulate insulin and glucagon. The lizard protein remains effective much longer than the human hormone, helping diabetics keep their blood sugar levels under control. Exenatide slows the emptying of the stomach and causes a decrease in appetite, contributing to weight loss. The saliva of the Gila monster contains many chemicals which can be deadly. One of these has been shown to affect memory. Several companies have been researching the abilities of this chemical to help memory loss due to various diseases such as Alzheimer’s, Schizophrenia, and Attention - Deficit Hyperactivity Deficiency (ADHD). Gilatide, derived from exendin - 4, has been shown to dramatically heighten memory in a study with mice. Gilatide is likely to be researched further to provide help to Alzheimer’s patients.

After ten years of research and development, the rights to develop and market the drug were purchased for $325 million. The drug, marketed as ‘Byetta’, is used to treat some of the 17 million type - 2 diabetes patients in the U.S. alone.

Such is the power of the Poison Paradox. A very important point that underlines the entire story is the need to conserve biodiversity whether terrestrial or marine to harness the rich treasure trove of Nature’s miraculous molecules. Or else they will be lost forever.

Pratap Chhetri