Even in times of Charaka and Sushrutha ailments due to stress particularly related to the cardiovascular system were recognised as important occupational problems. In the modern times these problems have reached alarming proportions attracting the attention of the medical profession throughout the world. The role of plants in treating these diseases has already been established by the celebrated species from the classical texts like Rauvolfia serpentina. A number of other species, with similar effects, are also known. There are species that can serve as hypotensives, hypertensives, cardiotonics, cardiotoxins, cardiac stimulants, cardiac depressants, etc., which have several roles to play in the treatment of the complex group of cardiovascular ailments. A list of 27 species of plants in these categories is given in Appendix 16

PLANTS WITH EFFECTS ON THE NERVOUS SYSTEM

Plants with effects on the nervous system have been of interest to man since time immemorial. The development of medicine itself was closely connected with plants with psychic effects. In many societies, even today, there are medicine men (and women) who use psychoactive plants in the treatment of disease. Some plants like Papaver somniferum, Erythroxylon coca and Cannabis sativa have been subjected to pharmacological studies and have been in use in modern medicine since long.

Several species of plants exert their influence on the central or autonomic nervous system. A number of chemical compounds which are antihypertensives, hallucinogens, depressants, antidepressants, spasmodics, antispasmodics, etc., have already been discovered from some species in Appendix 17. An intensive

search is required to discover more species with effects in this area. Many of such species are likely to contain compounds which would be useful as analgesics and local anesthetics. For this reason, the 44 species in Appendix 17 should be evaluated along with those in Appendix 14 (analgesics). Since the species in Appendix 9 also have effects on the central nervous system, they too should be taken into consideration simultaneously.

PLANTS WITH ANTI-INFLAMMATORY AND ASTRINGENT EFFECTS

Inflammation is one of the most common reactions of the living tissues of our body to irritation, injury, or infection. Inflammation, characterised by pain, swelling, redness and heat, results in a severe damage to the tissues and hence requires immediate measures to reduce suffering by the patient and to prevent an excessive damage to the tissues. Inflammation is one of the basic factors in some diseases like rheumatism and arthritis. A number of drugs can control inflammation (anti-inflammatory drugs) and these are in great demand.

An astringent is a drug that contracts organic tissue and lessens its secretions. Though astringent and anti-inflammatory activities are different, in practice the distinction sometimes becomes obscure as astringent effects overlap to some degree with anti-inflammatory activity. Hence species with these two effects are treated here together and the list of 142 plants is given in Appendix 18.

PLANTS INFLUENCING FERTILITY

A number of species of plants are known to promote fertility as they contain sex hormones. Some species inhibit conception, by their action as spermostatics, spermicides, anti-implantants, abortifacients, etc. Plants active in the males or females can be selected for use, in population control. A list of 37 species which merit a proper evaluation is given in Appendix 19. In addition to these, species containing sperm agglutinating lectins or sperm lysing saponins, that can be of use as spermostatics and spermicides, respectively, are detailed in the sections dealing with lectins and saponins, later on.

PLANTS USED IN TRADITIONAL TOXICOLOGY

Toxicology is the study of poisons and their antidotes.

Recognition of toxic species of plants is a faculty not confined to man; primates, and even non-primate mammals are known to avoid them. ‘The plant which the goat does not touch’ (aadu muttada gida) is the Kannada name for Tylophora indica.

Poisonous and psychoactive plants were among the first of non-food plants man had learnt to use. Specific use of poisonous plants was made in all cultures, as reflected in the use of arrow poisons. The medicine man (or woman) has used them effectively, in keeping a hold on the population, occasionally curing a patient or two.

Like in every other culture, in India too, poisonous plants have occupied a prominent place on the minds of medical men and their literature. Toxicology was dealt in detail by both Charaka and Sushratha and is one of the eight major aspects of Ayurveda (Damstra chikitsa). Chanakya, also known as Kautilya, the master of chicanery and political intrigue, and the master of ancient Indian economics, is believed to have had an extensive knowledge of Indian poisonous plants. Koutilya is credited with a compilation of detailed information on over 180 species of poisonous plants, their effects, uses, dosage, mode of administration, camouflaged administration, slow poisoning and the antidotes for them. Poisonous plants were among very important secret weapons in settling personal and political scores, in several parts of the world, all the time.