Alkaloids are the secondary metabolites of plants. They are internal constitutes of plants so called as biomolecules.
Uses of alkaloids are based on their toxic effects on the body.
Their toxicity is seen by changes in body physiology when administered or consumed.
But some of these toxic effects are useful in-terms of health when used at right doses. Excess doses will be definitely poisonous and harmful to man.
Chemically they contain nitrogen in them and so are alkaline in nature. They are also less soluble in water. They can be found in different parts of the plant like leaves, stem, bark, roots etc.
The alkaloids are mainly obtained from plants which are shrubs and herbs.
5 Uses of alkaloids:
- As medicines.
- As Euphoric & addicting drugs
- As pesticides or insect repellents.
- For research and scientific study.
- To catch animals.
In medicine. Uses of alkaloids mainly means their use in health care. They act as life saving drugs in some serious disorders like heart-failure, cancer, blood pressure etc.
Digoxin- is used for heart-failure. This helps to improve the heart function and maintain life.
Vincristine from vinca roseus is used as anticancer drug.
Ephedrine from ephedra is used in blood pressure.
codeine is used as cough suppressant.
Ergot alkaloids are used as drugs to relieve migraine,
Euphoric & addicting drugs: Many psychotropic substances like marijuna, cannabis, opium sort if substances are alkaloids. They have been used since ancient period as a instruments for mental excitement and euphoria. Though they are considered harmful as per modern medicine. They were in full fledged use by kings and common for fun and as part of recreation. Even now many people consume them by procuring them illegally.
Insect repellents and pesticides. As mentioned earlier, these alkaloids are toxic in nature. They be toxic in varying concentrations. Alkaloid pyrethrin is used as insect repellent in mosquito coils, mosquito repellents and even in agriculture. Lucky enough, at such concentrations, these insecticides are less toxic to humans but affect mosquitoes to leave the vicinity.
For research and scientific study: Due to their specific effects on body, they are used in research and scientific study. For example, atropine an alkaloid can cause dilation of pupil. To test if a new substance is having similar effects or opposite effects, it is compared with atropine. So here atropine is used as standard for comparison in research.
To catch animals: Heavy animals like elephants, were captured by making them immovable. For this the hunters use arrow poison ( D-tubocurarine) which is applied to the point of arrow and shot at animal. When the arrow gets stuck to the animal, the alkaloid (D-TC) will enter the muscle and cause paralysis. This is a short term action and is reversible. Since the animals are immovable, they can be trapped and transported. The same can be used for deer, wild animals etc.
Besides the above, alkaloids are produced by plants and large trees. They are waste products of body metabolism. They are excreted through leaves, fruits etc. They are toxic in nature, so they help the plant by preventing animals from grazing on them. Thus these alkaloids save the plants from extensive grazing by cattle. Due to bitter taste and other poisonous effects in the body, animals do not prefer to feed on plants containing alkaloids