Abstract

Since remote times herbal medicines are the primary sources of health cure of the rural people throughout the world. The knowledge on the medicinal plants is inherited from generation to generation in the family of herbal doctors. Although significant advances have been made in modern allopathic medicine, medicinal plants are extensively used even in the cities specially in Mexico and Medicinal plants are largely sold both in the rural and urban markets. One of the reasons is due to the no-availability of good doctors in the rural areas, high confidence of the rural people and high cost of the allopathic medicine. In Mexico although several hundreds of medicinal plants are known to alleviate various types of diseases, still many species are not yet explored from the rural areas. There is a great necessity to formulate a systematic research starting from ethnobotany, botany and pharmacognosy including histochemistry and finally phytochemistry. With these objectives, some advances have been made on some medicinal plant species both in north-east and high land valleys of Mexico obtained mainly through research projects and thesis projects both in the bachelor and post-graduate levels. In the first step in the north-east of Mexico, through several visits in the rural areas and herbal shops and interviews a list of common species has been made, collected and preserved in the herbarium sheets. Then on the basis of a very careful analysis, most important and common medicinal species was selected for the studies on pharmacognosy, histochemistry and pharmacological tests on animals. An analysis of pharmacognosy showed the presence of distinct morphological, anatomical and histochemical characters in each species which can distinguish among species. In the high land valleys in Puebla and Tlaxcala, a more systematic interdisciplinary research has been undertaken including ethnobotany, pharmacognosy and some preliminary phytochemistry of several medicinal plant species. The efficacy of some medicinal plant species used by the herbal specialists has also been confirmed by a specialist of high recognition in the city. The species studied are: Artemisia absinthium, Chamaemelum nobile, Chenopodium ambrosoides, Ocimum sanctum, Origanum vulgare, Origanum majorana, Lavandula angostifolia, Marrubium vulgare, Mentha spicata, Rosmarinus officinalis, Salvia officinalis, Semipervivum tectorum, Thymus vulgaris and Turnera vulgaris. The medicinal herbs contained several secondary metabolites, among which alkaloids, saponins, triterpenes, flavonoids, cyanogenic and cardiotonic glucosides, the presence, absence and intensity of which vary among species. Although sufficient researches have been concentrated mostly on the phytochemistry in Mexico, no systematic research has been undertaken as planned. A catalogue of some medicinal plants has been made and some medicinal plant species are grown in the green house. Finally, a systematic research plant has been suggested on the medicinal plants. An interdisciplinary research including herbal specialists, botanists, agronomists and chemists is in progress.