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.

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.

Six pentacyclic triterpenes were isolated from hexane extract of stems of Maytenus salicifolia Reissek, Celastraceae: 30-hydroxyfriedelan-3-one (1), 3,16-dioxofriedelane (2), friedeline (3), lupeol (4), betuline (5) and lup-20(29)-en-3,30-diol (6). The structure each one was established on the basis of detailed ¹H and 13C NMR spectral investigation and by comparison with the respective literature values. For compound 1, the complete 2D NMR (HMBC, HMQC and NOESY) spectral data were herein reported for the first time. Compounds 1, 2, 5 and 6 were isolated for the first time from this plant. Antioxidant activity is described for some extracts from species of the Celastraceae family, then, the extracts from aerial parts of M. salicifolia were evaluated in relation to antioxidant potential using the DPPH method. Compared to quecertin, the AcEt extract (EAF) from leaves, AcEt (EAPF) and MeOH (EMPF) from pulp fruit and AcEt (EAT) and MeOH (EMT) from stems showed significant antioxidant property.