Anti-hemorrhagic effect of hydro-alcoholic extract of the leaves of Mikania glomerata in lesions induced by Bothrops jararaca venom in rats

To investigate the effects of hydroalcoholic leaf extract of Mikania glomerata Spreng (Asteraceae) on the activity of Bothrops jararaca snake venom in Wistar rats. METHODS: Fifty four rats Wistar were divided into six groups of nine animals in each: control treated with saline; control treated with B. jararaca venom; control treated with M. glomerata extract; B. jararaca venom incubated with M. glomerata extract at proportions of 1:1, 1:2, and 1:4. RESULTS: Histopathological and morphometric analysis showed that intradermal administration of snake venom incubated with the hydroalcoholic extract at proportions of 1:1, 1:2 and 1:4 promoted a significant reduction in the number of inflammatory cells and a marked decrease in edema after the third hour. There was also a significant reduction in the intensity of the hemorrhagic halo in animals receiving the snake venom incubated with the extract, with the observation of a progressive and parallel inhibition with increasing proportion of M. glomerata. CONCLUSION: The Mikania glomerata hydroalcoholic extract exerted effective anti-inflammatory and antihemorrhagic activity against the effects induced by Bothrops jararaca snake venom.

Antiproliferative activity, isolation and identification of active compound from Gaylussacia brasiliensis

Gaylussacia brasiliensis (Spreng.) Meissn., Ericaceae, is used in folk medicine for treatment of several inflammatory processes and as healing agent. The scope of this work was to evaluate the in vitro antiproliferative activity of crude dichloromethane extract (CHD) and to identify the compound(s) responsible for this activity. CHD was evaluated and showed a concentration dependent inhibition on all cells lines. Therefore CHD was submitted to several classical columns chromatography providing the most active fraction (FC), inhibiting all cells line at 25 µg/mL. FC was further fractionated affording isolated compound 2β, 3β-dihydroxy-urs-12-ene-28-oic acid , identified on basis of 2D-NMR experiments and showed concentration-dependent activity and selectivity for kidney and breast cell lines.

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.

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 Artemisia 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 análise 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 (CE 50 de 130,6 mg.mL-1 e CE 90 de 302,9 mg.mL-1) que os extratos derivados. Esses resultados tendem a confirmar que a ação da artemisinina sobre as fêmeas 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 R.(B.) microplus.