Avaliação atraves de tecnicas de cultura de tecidos da produção de antimalaricos em genotipos selecionados de Artemisia annua L

AUTOR(ES)
DATA DE PUBLICAÇÃO

2000

RESUMO

Malaria is one of the most serious diseases in the tropical regions, with 300-500 million clinical cases and more than 1 million deaths a year. The patogenic agent, Plasmodium, which is transmitted by the bite of the Anopheles mosquito is resistant against the traditional medicines. One of the main treatment for resistent ma1aria caused by P. falciparum uses semi-synthetic artemisinin derivatives, a natural product from Artemisia annua L., native from China and adapted in various places, including Brazil. The main objective of this work was to evaluate A. annua hybrid genotypes rich in artemisinin and with late blooming, obtained by breeding program ofMED1PLANT and CPQBA/{JNICMlfP, with tissue culture techniques. We obtained transformed roots in Ch x Viet 55 hybrid by Agrobacterium rhizogenes and they were evaluated in relation to there potential growth, artemisinic acid production and effects of gro 1h reguiators of cultures "in vitró". The biomass growth peak was on the 28fu day of cultivation, and the greater dedifferentiation with the addition of auxin in the culture medium, in accordance with results obtained previously in non-transformed tissues. The transformed root cultures showed greater yields of artemisinic acid (0,48 g/ kg dry weight) than normal roots (0,16 g / kg dry weight), but the yields were not sufficient for commercial cultivation. We also obtained a micropropagation and climate adaption protocol for Ch x Viet 55 and 39 x IV hybrids, that resulted in a 50-60 plants phenotipica1ly identical to the original plants in each subculture, and we obtained maximal rooting (100%) in 2 mg!L IBA, 12 days afier seedlings were transferred. The cUIVes of growth and mass production, and the analysis of sugar and artemisinin did not show differences between micropropagated and original plants, and they validated micropropagation process to maintenance of hybrid and parental plants. fu the final experiment, we cultivated and climate adapted Ch x Viet 55 and 39 xIV hybrids, and we compared them with a non selectedA. annua population. The hybrids showed a growth superiority in association with high levels of artemisinin, protein, sugar, chlorophyll and carotenoids. The hybrids resulted if 37,72 mg artemisinin fi each plant (dry leaves), against 11,61 mg if non selected population. Chlorophyll and carotenoid levels were fi accordance with artemisinin levels showed by hybrids and non selected population, making clear the existence of a positive colt elation between these compounds: chlorophylls and carotenoids. These compounds have the same biossfithetically origin and these results make possible a fidirect measurement of artemisinin yields by chlorophyll and carotenoid analysis

ASSUNTO(S)

malaria - tratamento artemisia plantas medicinais

ACESSO AO ARTIGO

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