Antiparasitic Activity of Compounds Isolated from Ganoderma tuberculosum (Agaricomycetes) from Mexico.

The genus Ganoderma has a long history of use in traditional Asiatic medicine due to its different nutritional and medicinal properties. In Mexico, the species G. tuberculosum is used in indigenous communities, for example, the Wixaritari and mestizos of Villa Guerrero Jalisco for the treatment of diseases that may be related to parasitic infections; however, few chemical studies corroborate its traditional medicinal potential. Thereby, the objective of this study was to isolate and identify anti-parasitic activity compounds from a strain of G. tuberculosum native to Mexico. From the fruiting bodies of G. tuberculosum (GVL-21) a hexane extract was obtained which was subjected to guided fractioning to isolate pure compounds. The in vitro anti-parasitic activity of the pure compound (IC50) was assayed against Leishmania amazonensis, Trypanosoma cruzi, Acanthamoeba castellanii Neff, and Naegleria fowleri. Furthermore, the cytotoxicity (CC50) of the isolated compounds was determined against murine macrophages. The guided fractioning produced 5 compounds: ergosterol (1), ergosta-4,6,8(14),22-tetraen-3-one (2), ergosta-7,22-dien-3ß-ol (3), 3,5-dihydroxy-ergosta-7,22-dien-6-one (4), and ganoderic acid DM (5). Compounds 2 and 5 showed the best anti-parasitic activity in an IC50 range of 54.34 ± 8.02 to 12.38 ± 2.72 µM against all the parasites assayed and low cytotoxicity against murine macrophages. The present study showed for the first time the in vitro anti-parasitic activity of compounds 1-5 against L. amazonensis, T. cruzi, A. castellanii Neff, and N. fowleri, corroborating the medicinal potential of Ganoderma and its traditional applications.

The sea-hare Aplysia brasiliana promotes induction in chemical defense in the seaweed Laurencia dendroidea and in their congeneric neighbors.

Inducible chemical defenses are more common in temperate seaweeds than tropical ones, and are directly detected by increase of chemical contents, or indirectly by differential consumption of live seaweed tissues or artificial food with algal extracts by herbivores. In general, seaweed-induced chemical defense occur between 11 and 20 days after both simulated/artificial or direct herbivory. Here, we used experimental procedures to assess induced chemical defense in the tropical red seaweed Laurencia dendroidea as response to direct grazing, chemical cues from grazed conspecific neighbors and only presence of herbivores. Chemical defenses were analyzed by detecting the palatability of artificial food containing L. dendroidea extracts offered to Aplysia brasiliana and by comparative analyses of extracts from this seaweed by Gas Chromatography/Mass Spectroscopy, as well as metabolomic data analysis by Principal Component Analysis. Our results revealed that direct grazing by A. brasiliana induced a rapid (after 48 h) response among individuals of L. dendroidea, as did waterborne chemical cues from grazed conspecifics, but the presence of sea hare alone did not elicit a response. Increased resistance to grazing was accompanied by significative changes in sesquiterpene metabolomic chemical profile, revealing that induced defense: may be more widespread among seaweeds, independent of latitude; can involve changes in other classes of substances besides phlorotannins or not only the increase in the content of a single compound; and may be a rapid and ecologically coherent response to consumers. In addition, the importance of incorporating the metabolomic approach when examining inducible chemical defense in seaweeds is also emphasized.