ABOUT SCIENCE

Ethnobotany | About Ethnobotany - Human societies use plants in many different ways for food, medicine, shelter, clothing, tools, ceremonial functions, and other purposes. Ethnobotany is the study of how people use plants, and ethnobotanists generally conduct their work by interviewing local peoples and studying their traditions and habits. Paleoethnobotanists focus on plant use in prehistoric times by examining seeds, pollen, wood, and other plant remains found at archaeological sites. Although ethnobotanists are interested in all types of plant use, the study of medicinal plants, with its potential for social and economic benefit, has always been of particular interest. In fact, ethnobotanical investigations have led to the development of numerous important medicines. Quinine, the first antimalarial drug, comes from the bark of  cinchona trees, long used in native Peruvian medicine to treat fever, digestive ailments, and malaria. Aspirin originally came from willow bark, which has been used for thousands of years to relieve pain. More recently, Madagascar periwinkle, a plant used by several native peoples for diabetes and other conditions, provided two new cancer drugs.

Scientists pursuing drug development have traditionally relied on the knowledge of local healers in their search for promising plants. However, the development of modern drugs from medicinal plant compounds leads to a difficult ethical issue. What are the rights of indigenous peoples, and how can these be protected?

Critics are quick to point to the fact that cancer drugs developed from Madagascar periwinkle produced over a billion dollars in profit for the pharmaceutical giant Eli Lilly, but nothing for traditional societies in Madagascar. Some drug developers now attempt to ensure that local peoples also benefit. For example, when the AIDS Research Alliance found an anti-HIV compound in a Samoan medicinal tree, the group made direct contributions to the village where the tree was known and also promised 20 percent of the profits from drugs that are eventually developed. Unfortunately, because of the ongoing loss of native cultures and the extinction of plant species through deforestation and habitat destruction, it is all too likely that many medically useful species will never be known.

The Placebo Effect | about Effect of Placebo - A patient with knee pain goes in for surgery. He receives anesthesia, and cuts are made around his knee where the surgical instruments will be inserted. Afterwards, the surgery appears to be successful both pain and swelling are greatly diminished. What’s unusual about this story? Nothing, except that the operation was a sham. Cuts were made around the patient’s knee, but nothing happened after that.

Why does the patient feel so much better? Because of a phenomenon known as the placebo effect.*

Placebo is Latin for “I shall please.” It refers to the once regular practice in which doctors prescribed sugar pills to patients whom they otherwise couldn’t help. Although this is now considered unethical, it doesn’t change the fact that sugar pills did often help. The placebo effect is defined as the improvement patients experience when they are given a treatment with no relevance to their medical problem. 

Placebos appear to work for a wide variety of conditions and are usually far better than no treatment at all. In a study of patients with Parkinson’s disease, for example, a placebo worked just as well as medication in inducing the release of dopamine by the brain. Placebos have also been found to work as well as modern antidepressants in the treatment of depression. The placebo effect is certainly real, though placebos work better for some maladies than others.

Placebos appear to be particularly effective for conditions related to the nervous system, including pain, depression, anxiety, headaches, fatigue, and gastrointestinal symptoms. For most of these conditions, placebos have about 30–50 percent effectiveness nearly as good as “real” treatments in some cases. Placebos are also believed to account for the “success” of certain alternative remedies with no medical basis.

The placebo effect is one of the oddest phenomena in medicine.

What causes it? This question has not been fully answered and is the object of continued study. However, several possible mechanisms have been suggested. One idea is that the placebo effect operate through the release of endorphins. Release of the body’s natural opiates would explain why placebos are so good at treating pain. Further evidence comes from the fact that placebos become much less effective as painkillers when patients are given a drug that blocks the opiate receptors. However, because the placebo effect works for many symptoms other than pain, this can’t be the whole story. Another idea is that receiving a placebo reduces stress, allowing the immune system to function more effectively. Numerous studies have shown that stress reduces the immune system’s capabilities consequently, stress relief would be expected to improve its function.

Still, there must be more to it than this because the placebo effect is very specific it doesn’t help with all your ailments, only the one you think you’re being treated for. There is no getting around the fact that a person’s expectations somehow lie at the crux of the placebo  effect. Some scientists have argued that the placebo effect is a conditioned reflex. The patient has, through numerous experiences with doctors, pills, injections, and so on, been conditioned to expect a positive effect after medical treatment. And somehow, the nervous

system has become wired to comply. 

Interestingly, studies have also demonstrated a “nocebo effect,” sometimes called the placebo effect’s “evil twin.” Expectations of negative effects are realized too. For example, people on placebos often develop negative “side effects” from their treatments. Side effects of real medications may sometimes be caused by the nocebo effect as well. For example, studies have repeatedly shown that patients who were warned of specific side effects tend to experience them much more often than patients who weren’t warned. The nocebo effect can be even more serious. One study showed that women who believed they were vulnerable to heart disease were four times as likely to die of it as women who didn’t believe they were vulnerable, but had similar risk factors. The nocebo effect may also account for the effectiveness of voodoo death curses. Never underes timate the power of the mind.