In vitro antiviral activity of Brazilian plants (Maytenus ilicifolia and Aniba rosaeodora) against bovine herpesvirus type 5 and avian metapneumovirus.

CONTEXT: Medicinal plants are well known for their use in traditional folk medicine as treatments for many diseases including infectious diseases. OBJECTIVE: Six Brazilian medicinal plant species were subjected to an antiviral screening bioassay to investigate and evaluate their biological activities against five viruses: bovine herpesvirus type 5 (BHV-5), avian metapneumovirus (aMPV), murine hepatitis virus type 3, porcine parvovirus and bovine respiratory syncytial virus. MATERIALS AND METHODS: The antiviral activity was determined by a titration technique that depends on the ability of plant extract dilutions (25 or 2.5 µg/mL) to inhibit the viral induced cytopathic effect and the extracts' inhibition percentage (IP). RESULTS: Two medicinal plant species showed potential antiviral activity. The Aniba rosaeodora Ducke (Lauraceae) extract had the best results, with 90% inhibition of viral growth at 2.5 µg/mL when the extract was added during the replication period of the aMPV infection cycle. The Maytenus ilicifolia (Schrad.) Planch. (Celastraceae) extracts at a concentration of 2.5 µg/mL exhibited antiviral activity during the attachment phase of BHV-5 (IP = 100%). DISCUSSION AND CONCLUSION: The biomonitored fractionation of the active extracts from M. ilicifolia and A. rosaeodora could be a potential tool for identifying their active compounds and determining the exact mechanism of action.

Styryl lactones and their derivatives: biological activities, mechanisms of action and potential leads for drug design.

Nature is an inexhaustible source of natural compounds with interesting biological activities. In general, natural products are an important source of new compounds with a variety of structural arrangements and singular properties. Styryl lactones are a group of secondary metabolites ubiquitous in the genus Goniothalamus that have demonstrated to possess interesting biological properties, in particular antiproliferative activity against cancer cells. In general, the cytotoxicity of styryl lactones appears to be specific against cancer cells since insignificant effects of these compounds on normal cells are reported. A large body of evidence suggests that the antiproliferative activity of styryl lactones is associated with the induction of apoptosis in target cells. In the first part of this review we discuss the biological activities of styryl lactones focusing on cancer cells, the causal agent of Chagas' disease and the vectors for yellow fever and human lymphatic filariasis. Stru described in detail for ninety styryl lactones. The last part describes the molecular targets of styryl lactones for inducing apoptosis, as well as immunosuppressive and inflammatory processes. Overall, understanding how these compounds exert their activities in biological system is essential for future development and application of styryl lactones for human health.

Antiulcerogenic activity of a crude hydroalcoholic extract and coumarin isolated from Mikania laevigata Schultz Bip.

The leaves of Mikania (Asteraceae) species are used in folk medicine as antispasmodic, antiulcerogenic and antirheumatic agents. Phytochemical screening of the crude hydroalcoholic 70% extract (CHE) of Mikania laevigata Shultz Bip. revealed coumarins, terpenes and organic acids. Antiulcerogenic activity of CHE was evaluated, employing different experimental models in rats, to discern the pharmacological mechanism of action. Both the antisecretory and the cytoprotection hypothesis were evaluated. The crude hydroalcoholic extract (1000 mg/kg body wt., vo) decreased the ulcerative lesion index produced by indomethacin, ethanol, stress and reserpine in rats by 85%, 93%, 82% and 50%, respectively. In the pyloric ligation model, a decrease of hydrogenionic concentration (53%) was observed, suggesting that the pharmacological mechanism has a relationship to antisecretory activity. The antisecretory mechanisms of CHE and the coumarin isolated from M. laevigata were confirmed by acid hypersecretion induced by histamine, pentagastrin and bethanechol. Duodenal administration of CHE (1000 mg/kg body wt.) and coumarin (100 mg/kg body wt.) inhibited only the gastric acid secretion produced by bethanecol. These results suggest that both CHE and coumarin may influence the secretion control mediated by the parasympathetic system.