Chemical and technological evaluation of the Phyllanthus niruri aerial parts as a function of cultivation and harvesting conditions

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.

In vitro activity of Artemisia annua L (Asteraceae) extracts against Rhipicephalus (Boophilus) microplus / Atividade in vitro de extratos de Artemisia annua L (Asteraceae) sobre Rhipicephalus (Boophilus) microplus

The activity of plant extracts on parasites may indicate groups of substances that are potentially useful for controlling Rhipicephalus (Boophilus) microplus. The aim of the present study was to investigate the in vitro action of Artemisia annua extracts on this tick. The concentrations of the sesquiterpene lactones artemisinin and deoxyartemisinin present in plant extracts were quantified via high-performance liquid chromatography. Four extracts produced from the concentrated crude extract (CCE) were evaluated on larvae using the impregnated paper method, with readings after 24 hours of incubation. The engorged females were immersed in the CCE and in its four derived extracts for five minutes, with incubation for subsequent analysis of biological parameters. The extracts were not effective on the larvae at the concentrations tested (3.1 to 50 mg.mL–1). The CCE showed greater efficacy on engorged females (EC50 of 130.6 mg.mL–1 and EC90 of 302.9 mg.mL–1) than did the derived extracts. These results tend to confirm that the action of artemisinin on engorged females of R. (B.) microplus is conditional to their blood intake. In this case, in vitro methods would be inadequate for effective evaluation of the action of A. annua on R. (B.) microplus. (AU)

A atividade de extratos vegetais sobre parasitas pode indicar grupos de substâncias de uso potencial no controle de Rhipicephalus (Boophilus) microplus. O objetivo do presente estudo foi investigar a ação in vitro de extratos de Artemísia annua sobre esta espécie. A concentração das lactonas sesquiterpênicas artemisinina e deoxiartemisinina presentes nos extratos vegetais, foi quantificada via cromatografia líquida de alta eficiência. Quatro extratos produzidos a partir do extrato bruto concentrado (EBC) foram avaliados sobre larvas pela metodologia do papel impregnado, com leitura após 24 horas de incubação. As fêmeas ingurgitadas foram imersas por cinco minutos no EBC e nos seus quatro extratos derivados, e incubadas para posterior análiise dos parâmetros biológicos. Os extratos não tiveram eficácia sobre as larvas nas concentrações avaliadas (de 3,1 a 50 mg.mL–1). O EBC apresentou melhor eficácia sobre as fêmeas ingurgitadas (CE50 de 130,6 mg.mL–1 e CE90 de 302,9 mg.mL–1) que os extratos derivados. Esses resultados tendem a confirmar que a ação da artemisinina sobre as f麥eas ingurgitadas de R. (B.) microplus estaria condicionada à sua ingestão através do sangue. Nesse caso, os métodos in vitro seriam inadequados para a efetiva avaliação da ação de A. annua sobre R. (B.) microplus. (AU)

New hybrid lines of the antimalarial species Artemisia annua L. guarantee its growth in Brazil

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.