1. Besides their own essential principles, the so-called primary plant products, plants produce other principles, which apparently do not have any definite biological function.
2. Medicinal plants are important for many reasons: they provide us with natural drugs, active constituents and intermediates for semisynthetic drugs.
3. Their biological function is often discussed but the fact is that many of them have a special importance outside the plant because of their pharmacological action.
4. This situation may be complicated when there are synergistic or antagonistic principles or substances with other pharmacological effects in the plant at the same time.
5. Plants that give drugs have both active and inactive substances.
6. Drugs in general arise from a heterogeneous population of individual plants living under a variety of conditions.
7. Inactive substances include cellular structures and pharmacological inactive compounds.
8. Nature produces an astonishing variety of complex phytoconstituents which embrace all fields of pharmacological action.
II. Reading
Phytopharmacy
Phytopharmacy is the study of the plants that are used as drugs and the drugs that are isolated from plants. Medicinal plants are important for many reasons: they provide us with natural drugs, active constituents and intermediates for semi-synthetic drugs. Nature produces an astonishing variety of complex phytoconstituents which embrace all fields of pharmacological action.
Plants are constantly metabolising, both breaking down preformed molecules and building new ones at the same time. Besides their own essential principles, the so-called primary plant products, plants produce other principles, which apparently do not have any definite biological function. These are the so-called secondary products. Their biological function is often discussed but the fact is that many of them have a special importance outside the plant because of their pharmacological action. Plants that give drugs have both active and inactive substances. The inactive substances include cellular structures and pharmacological inactive compounds.
A plant seldom has only one active principle. Often it produces a series of structurally related compounds having similar pharmacological properties. In this case it is possible to use either the total principles or the isolated and chemically pure compounds. This situation may be complicated when there are synergistic or antagonistic principles or substances with other pharmacological effects in the plant at the same time. Also the inactive compounds may interfere with the action of the active ones or they may be their precursors. The inactive principles may alter the activity of the drug by physical means, for example, they may act as co-solvents of the active compounds or delay their absorption or diffusion in the organism.
Drugs in general arise from a heterogeneous population of individual plants living under a variety of conditions. Therefore, it is not surprising that their quality is affected by their variability, which is due to two main causes: intrinsic (endogenous) factors inherent to the genetic constitution and independent of external conditions; and extrinsic (exogenous) factors dependent on the ecological and environmental conditions in which the plant grows. Sometimes intrinsic factors are latent in the plant and only appear as a response to the appropriate external factors.
III. Language development
