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| HEALTH TRIBUNE | Wednesday, August 9, 2000, Chandigarh, India |
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Exercise body for mind Low-dose aspirin
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It is TB’s might versus flower power
The textbooks of medieval medicine are being revisited by scientists who plan to use modern biotechnology to update and revive ancient herbal remedies for diseases ranging from cancer and heart disease to tuberculosis (TB) and Alzheimer's
disease. A United Kingdom biosciences company, Molecular Nature, is working with the government's Institute of Grassland and Environmental Research (IGER), Aberystwyth in Central Wales, extracting 100 compounds a month from plants with ancient reputations for medicinal powers, and testing them for effectiveness against disease, and other valuable properties, in the laboratory. Wild flowers known as bluebells, for instance, were used
by Welsh monks in the 13th century to treat leprosy, which is caused by the same group of micro organisms as those that cause TB, the mycobacteria. Extracts from bluebells now show promise against TB. Much scientific research has already been focused on the potential value of drugs from tropical plants but for less has been done on drugs from plants that grow in the temperate world. The scientists involved point out that aspirin was first found in the temperate weed meadowsweet; taxol used to treat ovarian cancer is extracted from the yew tree; artemisin from the weed mugwort, and the heart drug, digitalis, from the foxglove. "If you look at the folklore of the plants that have when used to treat TB, you find that almost no work has been done on them because until quite recently TB was generally thought of as having been cured generations ago," said Dr Robert Nash of the MER, who is also research director of Molecular Nature. Bluebells have been found to contain a wide range of novel compounds which are closely related to a group known to have anti-viral and anti-cancer activities. Modern techniques make it possible to extract individual compounds from plants such as the bluebell and to test them one by one against diseases until the active compound or compounds are found. A compound from the bluebell is thought to attack mycobacteria by preventing rhamnose, a related compound which is a vital constituent of mycobacterial cell walls, from becoming incorporated into those walls. The bluebell compound replaces rhamnose and so distorts the structure of the cell walls. Dr George Fleet of Oxford University's Dyson Perrins laboratory, southern England, is working with Molecular Nature to identify these rhamnose analogues and synthesise them artificially for tests. New drugs with just such completely novel properties are badly needed to combat strains of TB that have become resistant to the drugs and antibiotics used today in parts of the developed and developing world. Drug-resistant TB is now a massive problem. Dandelions, sea pinks and nettles are other plants used in traditional medicine that are being investigated by Molecular Nature. Several chemicals have been extracted from clover, in an attempt to discover what may have been responsible for the anti-tumour activity which led to clover's use to treat cancer for hundreds of years before the advent of modern pharmaceuticals. Daffodils are now being cultivated in East Anglia for the extraction of galanthamine, used to treat Alzheimer's disease. Dr Maria Inez Chicarelli, managing director of Molecular Nature Limited (MNL), said: "There is no doubt that temperate plants produce large numbers of biologically active
metabolic for protection against herbivores and pathogens." Of course the pathogens which prey on plants are different from those which prey on people. But they often have much in common and may even belong to the same species. The fact that such natural
defence have evolved over millions of years makes them very effective compared to man-made drugs. The state-of-the-art analytical techniques (such as gas chromatography and high pressure liquid chromatography coupled to mass spectrometry) developed by the IGER and used by MNL allow novel compounds with exciting properties to be discovered in plants which have already been screened using less sensitive methods. For example, alkaloids thought to be important both in natural resistance to pests and in promoting human health have recently been discovered in the potato and aubergine. The ability to identify and extract single active compounds from the thousands of different chemicals present in plant tissue means that when such compounds are identified, if they are relatively simple compounds they may be artificially synthesised for use as drugs or for other purposes, since this may be cheaper than extracting them from plants. More complex compounds will probably be most economically produced in plants grown as crops. Clues to some of these come from the texts of ancient Welsh herbalists, such as the physicians of the Myddfai dating from the 13th century. Other clues come from family lore. "We have been getting letters from Welsh grandmothers," said Dr Chicarelli. For more information contact: Dr Maria Inez Chicarelli, Molecular Nature Limited, Plas Gogerddan, Aberystwyth, Ceredigion, SY 23 3EB, UK. Tel: 1970 823 201. Fax: 1970 823 209.
o Bluebells have been found to contain a wide range of novel compounds which are closely related to a group known to have anti-viral and anti-cancer activities. Modern techniques make it possible to extract individual compounds from plants such as the bluebell and to test them one by one against diseases until the active compound or compounds are found.
Clover against cancer
Several chemicals have been extracted from clover, in an attempt to discover what may have been responsible for the anti-tumour activity which led to clover's use to treat cancer for hundreds of years before the advent of modern pharmaceuticals.
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Exercise body for mind Just as regular exercisal work-ups strengthen the heart, the lungs, the bones and the muscles, primarily by improving blood circulation and also the supply of nutrients to these organs and tissues, these power the brain too — for similar reasons. High on the list of self-help techniques to improve the brain's functioning and to prevent age-related cognitive slumps, therefore, is exercise (CF ABC of Human Mind — a Reader's Digest publication). Although cognitive decline with age is inescapable, it certainly can be retarded by regular exercise, not necessarily a strenuous one. Physical exercise, more so that of the aerobic kind, helps the brain in many ways. Persons who exercise regularly improve both physically and mentally, are less likely to be anxious or depressed and are generally better equipped to cope with mental fatigue. Exercise does even help older people in forestalling memory loss and in keeping the brain fit, leading to better reflexes and increased mental equity and alertness. Exercise heightens the sense of well-being. A vigorous workout stimulates the body to pump out the so-called stress hormones such as cortisol and epinephrine that put the body in a state of alertness to react appropriately and less intensely to the anxiety-provoking events. Exercise also stimulates the brain to secrete more of endorphins — the brains' natural opiates that mimic the action of morphine and have pleasurable and pain-suppressing effects which produce a natural high. Exercisal workouts are vital for cardiovascular health. Improving the blood/nutrient supply to the body as a whole is imperative. Older people, in particular, should undertake appropriate exercises suiting their state of health. It is now being accepted that neurones of the hippocampus region (memory centre) in the human brain continue to divide throughout life, a finding that has significant implications in mental functioning as people age (Health and Nutrition, September 1999). Mice, when subjected to strenuous exercise, add "vigorously" to the brain neurones and the same is expected to happen in the human brain. "Time may make you older but perhaps workouts make you wiser" is the conclusion of the study undertaken by the Salk Institute (USA). Efforts made in youth to remain mentally agile signify an investment in the future to guard against age-based mental deterioration. Science has established that the supply of the nutrients alone, which undoubtedly gets improved by exercise through better circulation, is not enough to sustain neurologic health. It is only one of the many factors that impinge on brain-functioning. To keep the brain healthy, mental exercises are no less important. Skill-based exercises, scientists feel, are one of the best ways to ward off age-related mental deterioration. The continuous use of the mental faculties is the paramount factor in keeping the brain fit. An ever-engaged brain, supported by an adequate nutrient supply over the years registers an increase in the number of dendrites — the thread-like cytoplasmic extensions of the brain neurones — as well as synapses — the regions of function between the processes of two adjacent neurones. The number of dendrites as also the synapses per neurone is a fairly good criterion to judge its efficiency with since both these equip the neurones better to process information speedily and more efficiently. The brain's ability to add to the number of dendrites in its neurones, no doubt, is most strong in children. (when the brain is still developing and tapers off as we age), but it never disappears. To stay mentally active, we need to ensure that new dendrites and synapses continue to be added, and exercise helps significantly in this area. An idle brain develops fewer such connections, thereby impeding faster reflexes, increased memory and faster information retrieval. It is advisable, therefore, to continue thinking, memorising and teasing (trying to retrieve forgotten information) the brain to sharpen the cognitive skills. A survey done on third and fourth graders in New York and Los Angeles yielded interesting observations. Psychologists added either 45 minutes of chess instructions (newer mental activity) or 45 minutes of extra schoolwork (repetitive and thus boring) to their weekend schedules and found that after one semester, the chess-players significantly outperformed the academic group on reading tests. If you can work up a "mental sweat" doing something which also is fun, you have tingled your brain to improve. Mental exercises are more crucial to the aged, in particular, to stall deteriorative changes which become faster with age. There is no better way to stay sharp than to engage oneself in useful conversation or discussion. Pondering over thought-provoking ideas or other useful positive activities, including solving puzzles, have their own advantages. Certain games like chess or even cards are good mental "teasers". Constructive reading and writing provide the much needed mental exercise. The development of a new type of imaging of the brain whereby it is possible to monitor changes in the
blood flow to the brain is a good development. It is revealed that when the brain is actively involved in cognitive exercise,
blood flow (nutrient supply) to the areas actively involved is temporarily increased — just like the blood supply to the organs being physically exercised. Brain tonics or cognitive enhancers churned out by many multinationals worldwide have doubtful efficacy in stalling the cognitive slump in the elderly says Health Action International. Mostly these tonics are
cerebrovasodilators which temporarily improve the blood supply to the brain. But theories linking senile dementia to inadequate blood flow to the brain are considered outdated. Energise your brain through exercise and reap the dividend. Mental slowing catches up with age, especially after mid-life. Strangely though, one in five elderly people suffers no mental deterioration with age. Studies suggest that people who have held mentally demanding jobs in their early years are less likely to develop mental dementia vis-a-vis those whose minds were not habitually roused — ever. Learning is a continuous activity and since it is "mentally nourishing", one should continue with it as long as feasible. Caution: Physical exercise does boost brain function. However, people with fragile health, especially the aged, should avoid strenuous workouts. For them, walking, perhaps is the safest exercise; it is adjustable suiting the state of one's health. Dr Kanwar is a former Chairman of the Department of Biophysics at Panjab University, Chandigarh.
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Low-dose aspirin For about two decades, more and more patients are being prescribed a regular daily dose of aspirin to prevent heart attacks and strokes. There are questions which need clear-cut answers such as: Who should take aspirin, how much and for how long? Should people, who are apparently healthy, take it as a preventive step? At the outset, it may be clarified that aspirin is taken not for its pain-relieving effect but for its effect of preventing the clotting of blood (thrombosis) within the arteries, which is the immediate cause of a heart attack or a stroke. The platelets in our blood clump together to initiate the process of thrombosis. Aspirin prevents clumping. It is this anti-platelet effect that is utilised for the prevention of heart attacks and thrombotic strokes. For this purpose, doctors used to give one tablet (325 mg) of aspirin daily. It was found that in larger doses, its anti-platelet effect was lost while its untoward side-effects became more common. It has now been found that for anti-platelet effect only 20 mg of aspirin daily is sufficient. To take into account any irregularity of absorption from the gut, 50 mg per day is adequate and more than 150 mg (i.e half the usual tablet) is undesirable because then its harmful effects start appearing. For all practical purposes a dose varying between 50 mg and 100 mg daily is now considered adequate and safe by the majority of the doctors. It has to be given for the rest of life —daily and at the same time. Untoward effects and how to avoid them:
In larger doses, aspirin can cause haemorrhage from the stomach or internal organs, including the brain (haemorrhagic stroke). A small dose is, therefore, the correct amount to take. Rarely, even this amount can cause gout by raising blood uric acid. If you start suffering from gouty pains, get your uric acid checked. Who should take aspirin regularly? All survivors of heart attacks should take aspirin daily. All persons who have evidence of ischaemic heart disease (e.g angina) should take it. All persons above the age of 40 who have a strong family history of heart disease and/or multiple risk factors for heart disease such as smoking, high blood pressure, diabetes or high blood cholesterol should take it. The exception is that if there is a history of ulcer of the stomach or ulcer dyspepsia, aspirin should not be taken. Your doctor may give you an alternative medicine such as dipyridamole. All persons above the age of 60 or 65 are presumed to have fatty deposits in their arteries. They may take preventive aspirin if their physician so advises them. Old people, who have no family history of heart attacks, any of the risk factors mentioned above, and are physically active, may not take it. The author is the former Chief of the Medical Unit at the Willingdon Hospital (now Dr Ram Manohar Lohia Hospital), New Delhi, and consultant in medicine and cardiology at the INAS Hospital, University of Tripoli. He is based in Ambala Cantt. |
