ABSTRACT Pharmacological activities as anti-inflammatory, anti-hyperuricemic, anti-gouty arthritis, antitumor and trypanocidal activities of the aerial parts from Lychnophora trichocarpha (Spreng.) Spreng. ex Sch.Bip., Asteraceae (Brazilian arnica) have already been proved. Eremantholide C is a sesquiterpene lactone and one of the active chemical constituents responsible for these activities presented by L. trichocarpha. Therefore, the aim of this work was to develop and validate a stability indicating HPLC method for eremantholide C. Eremantholide C stability was evaluated in L. trichocarpha ethanolic extract and in its isolated form. Analytical conditions employed C18 column, acetonitrile/water in gradient elution, flow of 0.8 ml/min at 30 ºC. To correct for the loss of analyte during sample preparation the use of coumarin as an internal standard was necessary. The developed method provides good separation and resolution of the peaks, allowing quantification of eremantholide C, isolated or directly in the ethanolic extract, in internal standard presence. Validation results showed that this method is linear in the concentration range 2–180 µg/ml, precise, accurate and specific. Stability studies showed that L. trichocarpha ethanolic extract and eremantholide C remain stable for 6 months when stored at room temperature and impermeable glass bottle, therefore they can be used safely and effectively within this period. While at 40 ºC there was stability loss, at 8 ºC a stability increase was observed for the extract and the isolated eremantholide C. Forced degradation studies showed that eremantholide C degraded under acidic and alkaline conditions and was stable for three days under neutral and oxidative conditions, and when exposed to high temperature. Thus, with the development of a stability indicative method and the application of it in eremantholide C stability studies, the results can guide the development of new products that adequately preserve the original features of the biologically active substance with quality, safety and efficacy.

ABSTRACT Gout is a destructive arthritis with a high prevalence worldwide. However, the available therapy is not able to increase life quality in many patients. Campomanesia velutina (Cambess) O. Berg, Myrtaceae, is used in Brazilian folk medicine to treat pain, inflammation and rheumatism. The aim of this study was to evaluate the potential of ethanolic and aqueous extracts from C. velutina leaves to treat hyperuricemia and inflammation in gout arthritis model. Ethanolic extract of leaves and aqueous extract of leaves were in vitro assayed on xanthine oxidase inhibitory effect and in vivo on an experimental model of oxonate-induced hyperuricemia in mice, liver xanthine oxidase inhibition and monosodium urate crystal-induced paw edema model. The extracts at both tested doses (100 and 300 mg/kg) reduced serum urate levels. They were also able to inhibit xanthine oxidase in vitro and in vivo, demonstrating that this might be the mechanism of action underlying the urate-lowering effects. In addition, the extracts showed significant anti-inflammatory activity on monosodium urate crystal-induced paw edema, especially aqueous extract (100 and 300 mg/kg) that reduced edema at all evaluated times. Rutin and myricitrin were identified in ethanolic and in aqueous extracts. In this study, myricitrin was able to reduce serum uric acid levels and inhibit liver xanthine oxidase at the dose of 15 mg/kg. The anti-hyperuricemic activity of rutin has been previously reported. Thus, rutin and myricitrin seem to contribute to the observed effects of ethanolic and aqueous extracts. The results demonstrated the ability of aqueous and ethanolic extracts to lower serum urate levels and to reduce edema induced by monosodium urate crystals. Therefore, they may contribute to the management of gout in the future.

Transformações químicas realizadas em eremantolida C (1), uma lactona sesquiterpênica isolada de Lychnophora trichocarpha Spreng. originaram cinco novos derivados: 1′,2′-epoxieremantolida C (2), 5-n-propilamino-4,5-diidro-1′,2′-epoxieremantolida C (3), cloreto de 5-n-propilamônio-4,5-diidro-1′, 2′-epoxieremantolida C (4), cloreto de 5-n-propilamônio-4,5-diidroeremantolida C (5) e 16-O-etileremantolida C (6). As estruturas químicas de todos estes derivados foram elucidadas com base nos espectros de IV, EM, RMN de 1H e de 13C e por meio de técnicas 1D e 2D. Eremantolida C e os derivados 2, 4 e 5 foram avaliados frente a cepas tripomastigotas Y e CL de Trypanosoma cruzi. Eremantolida C inibiu completamente o crescimento de ambas as cepas de parasitas, enquanto todos os derivados foram parcialmente ativos contra a cepa CL e inativos contra a cepa Y.

Chemical transformations of eremantholide C (1), a sesquiterpene lactone that was isolated from Lychnophora trichocarpha Spreng. led to five new derivatives: 1′,2′- epoxyeremantholide C (2), 5-n-propylamine-4,5-dihydro-1′,2′-epoxyeremantholide C (3), 5-n-propylammonium-4,5-dihydro-1′,2′-epoxyeremantholide C chloride (4), 5-n-propylammonium-4,5-dihydroeremantolide C chloride (5) and 16-O-ethyleremantholide C (6). The structures of all these derivatives were assigned on the basis of IR, MS, 1H and 13C NMR data by 1D and 2D techniques. Eremantholide C and the derivatives 2, 4 and 5 were evaluated against trypomastigotes Y and CL strains of Trypanosoma cruzi. Eremantholide C completely inhibited the growth of both the parasites strains while all derivatives were partially active against the CL strain and inactive against the Y strain.

The species of the genus Lychnophora, Asteraceae, are popularly known as "arnica" and are native from Brazilian savana (Cerrado). They are widely used in Brazilian folk medicine as anti-inflammatory, to treat bruise, pain, rheumatism and for insect bites. For evaluation of acute toxicity, the ethanolic extract was given to albino female and male mice. In open-field test, the extract of Lychnophora trichocarpha (Spreng.) Spreng. (0.750 g/kg) induced a significant inhibition of the spontaneous locomotor activity and exploratory behavior of the animals were observed 1 and 4 h after administration. In traction test, the same dose reduced the muscular force 1 h after administration. The exploratory behavior reduced significantly in the group that received 0.50 g/kg, 1 and 4 h after administration of the extract. The animals that received the doses of 0.25, 0.50 and 0.75 g/kg did not show any change of blood biochemical parameters comparing to control group and showed some histopathological changes such as congestion and inflammation of kidney and liver. The dose of 1.5 g/kg caused the most serious signs of toxicity. Histopathological changes observed was hemorrhage in 62.5% and pulmonary congestion in 100% of the animals. Brain and liver congestion was found in 62.5% of the animals.

A doença de Chagas, uma zoonose causada por Trypanosoma cruzi, afeta em todo o mundo cerca de 16 a 18 milhões de pessoas. Sua transmissão ocorre através das fezes de triatomíneos, insetos hematófagos conhecidos como barbeiro. Atualmente, a principal forma de transmissão da doença de Chagas em áreas urbanas é por meio de transfusão de sangue contaminado. A violeta de genciana é o único agente que pode ser empregado na quimioprofilaxia de sangue destinado à transfusão. No entanto, existem algumas restrições ao seu uso. A quimioterapia disponível para a doença de Chagas não é eficaz uma vez que as drogas disponíveis nifurtimox e benznidazol são ativas apenas na fase aguda da doença e apresentam sérios efeitos colaterais. Várias substâncias isoladas de plantas foram avaliadas como agentes anti-T. cruzi, objetivando encontrar drogas com menos efeitos colaterais e maior eficácia para a quimioprofilaxia e quimioterapia da doença de Chagas. Nesta revisão são apresentadas as substâncias de origem natural com atividade anti- T. cruzi.

Chagas'disease, a zoonose caused by Trypanosoma cruzi, affects 16-18 million people in the world. The most important mode of transmission of the disease is associated with the feces of several species of triatomine bugs that are strictly hematophagous. Actually, infected blood transfusion is the major mechanism of transmission in urban areas. Gentian violet is the only available prophylactic drug. Despite its effectiveness, there are some restrictions on its use. The available therapy of Chagas' disease is inadequate since the treatment of patients with the drugs nifurtimox and benznidazole presents serious toxic side effects. The search for new trypanocidal compounds to the treatment of Chagas'disease and to use for eliminating T. cruzi from blood, that are more effective and that do not affect red blood cells is the main goal in the prevention of Chagas' disease. In this review a large set of chemicals of plant origin are enumerated and their trypanocidal activity are briefly discussed.