ABSTRACT
Tea from Phyllanthus niruri L., Phyllanthaceae, aerial parts is commonly used by Brazilian folk medicine for its benefits on the treatment of genitourinary disorders, for what the polyphenolic compounds are mainly responsible. The yield of such compounds may be influenced by several variables related with the plant growth. The effects of planting periods and harvesting conditions are investigated in this work, including four different seasons. The cultivation was characterized by dry mass yield of aerial parts, and the effect of pruning was analyzed. Leaves, stems and their mixtures were analyzed after drying and milling. Loss on drying and water soluble extractives were used as physical parameters for quality control. Flavonoid content and gallic acid were chosen as chemical markers for this work. The spectrophotometric trial based on the aluminum chloride complexes was applied to evaluate the total flavonoids content. Gallic acid contents were measured from the water extractive solutions by high-performance liquid chromatography. The pruning caused a positive influence on the amount of leaves and stems. The highest flavonoids and gallic acid contents were found in the leaves, which were developed over the summer and the winter, respectively, both from the second harvesting (after pruning). Chomatographic profile by HPLC was characterizes by the presence of gallic acid and two other major peaks (not identified substances), which relation was peculiar to each aerial part. In conclusion, these results suggest that even under less favorable climatic conditions, in winter, the pruning seems to cause a strong influence over the P. niruri polyphenolics production. Indeed, the total flavonoids content, as well as the HPLC profile, can be used as indicative parameters of the ratio of leaves and stem in the vegetal raw material.
ABSTRACT
Malaria is still one of the greatest causes of mortality in the world; in Brazil there are over 500,000 reported cases each year. Malaria, caused by the protozoan Plasmodium, has been aggravated by the increasing resistance of Plasmodium to the traditional drugs chloroquine and mefloquine. The study of new drugs resulted in the identification of antimalarial activities of an endoperoxide sesquiterpene lactone, called qinghaosu or atemisinin, extracted from the leaves of Artemisinin annua L., of the Asteraceae family. The research work developed at MEDIPLANT (Switzerland) and CPQBA-UNICAPM (Brazil) involved the selection and breeding of genotypes rich in artemisinin and presenting high biomass followed by a second selection for adaptation to Brazilian climatic conditions. Through controlled hybridization between selected genotypes from China and Vietnam, genetic gain was obtained in terms of artemisinin content and population uniformity. Through the increase of biomass and artemisinin content (estimated by analytical monitoring), it was possible to increase the artemisinin production of 5 Kg/ha for the base population to approximately 25 Kg/ha for the genetically bred population. In the cultivation carried out in Brazil, 3 of 7 hybrid lines, 2/39 x 1V, Ch x Viet.55 and 1V x 2/43 produced respectively 25.43, 23.05 and 21.27 Kg of artemisinin/ha/cut, with 2 harvests possible per year. The cultivation of these new hybrid lines in Brazil is technically feasible and highly competitive, due to the production obtained.