Persea americana Mill.: Evaluation of cytogenotoxicity and phytochemical prospection of leaf extracts

Abstract Persea americana Mill., belonging to the family Lauraceae, is noteworthy for the large amount of ethnopharmacological information in its regard, attributing to it many and varied medicinal properties. The tea and alcoholic extracts made from its leaves are used in folk medicine to treat various ailments. This study was designed to analyze the cytogenotoxicity and underlying chemistry of aqueous and hydroalcoholic extracts of avocado leaves, using the Allium cepa and micronucleus tests. The results obtained by applying the experimental models demonstrate that the extracts did not have a genotoxic effect at any of the concentrations analyzed, and even demonstrated a certain protective effect, possibly due to the presence of flavonoids and phenols, both of which are antioxidant substances. However, the extracts did present a cytotoxic effect. There were numerous karyorrhectic cells and those with nuclear alterations related to cell death. At the highest concentrations, it was possible to observe cytoplasmic alterations and binucleated cells. The extracts also caused a significant reduction in the number of cells undergoing division. These effects can be a response to the phytochemical agents present in the extracts. The results suggest that the extracts contain bioactive components that deserve further studies related to cancer therapies.

The vulnerable Sporophila frontalis (Verreaux) and Haplospiza unicolor Cabanis as new hosts for Isospora sporophilae Carvalho-Filho, Meireles, Ribeiro & Lopes, 2005 (Eimeriidae) in Brazil.

Isospora sporophilae Carvalho-Filho, Meireles, Ribeiro & Lopes, 2005 was morphologically and molecularly identified from the double-collared seedeater Sporophila frontalis (Verreaux), which is categorised as 'vulnerable' by the International Union for Conservation of Nature and Natural Resources (IUCN), and from the uniform finch Haplospiza unicolor Cabanis in conserved and anthropomorphic/fragmented areas of Atlantic Forest in the southeastern Brazil. The oöcysts recovered from S. frontalis and H. unicolor had small morphological and genotypic differences that were not considered sufficient for the description of new species, but only different genotypes of I. sporophilae related to each host. This coccidian species was originally described from double-collared seedeaters Sporophila caerulescens (Vieillot) in a center screening of wild animals; therefore, this new report emphasises a potential occurrence of anthropomorphic dispersion of coccidia through illegal trade, seizures and reintroductions in the wild.

Isospora lopesi n. sp. (Apicomplexa: Eimeriidae) from the eastern white-throated spadebill Platyrinchus mystaceus Vieillot (Passeriformes: Tyranni: Tyrannidae) in South America.

A species of Isospora Schneider, 1881 (Protozoa: Apicomplexa: Eimeriidae) considered as new to science is described and characterised molecularly from the eastern white-throated spadebill Platyrinchus mystaceus Vieillot in the Parque Nacional do Itatiaia, southeastern Brazil. Isospora lopesi n. sp. has oöcysts that are subspheroidal to ovoidal, 18-24 × 18-22 (20.6 × 19.7) µm, with smooth, bilayered wall, c.1.5 µm thick. Micropyle and oöcyst residuum are absent, but one polar granule is present. Sporocysts are ellipsoidal, 12-16 × 8-11 (14.4 × 8.6) µm. The Stieda body is flattened to half-moon-shaped and sub-Stieda body is rounded. Sporocyst residuum is present, consisting of numerous spherules of different sizes. Sporozoites are vermiform with anterior and posterior refractile bodies and nucleus. Molecular analysis was conducted at the mitochondrial cytochrome c oxidase subunit 1 (cox1) gene. This new isolate exhibited similarity greater than 98% with Isospora spp. isolates from spectacled warblers Sylvia conspicillata Temminck, 1820. This is the fourth isosporoid coccidian described from New World tyrannid birds, but is the first to have a complementary molecular characterisation.