New drugs with antiprotozoal activity from marine algae: a review

The use of indigenous or remote popular knowledge to identify new drugs against diseases or infections is a well-known approach in medicine. The inhabitants of coastal regions are known to prepare algae extracts for the treatment of disorders and ailments such as wounds, fever and stomach aches, as for the prevention of arrhythmia. Recent trends in drug research from natural sources have indicated that marine algae are a promising source of novel biochemically active compounds, especially with antiprotozoal activity. Algae survive in a competitive environment and, therefore, developed defense strategies that have resulted in a significant level of chemical structural diversity in various metabolic pathways. The exploration of these organisms for pharmaceutical and medical purposes has provided important chemical candidates for the discovery of new agents against neglected tropical diseases, stimulating the use of sophisticated physical techniques. This current review describes the main substances biosynthesized by benthic marine algae with activity against Leishmania spp., Trypanosoma cruzi and Trypanosoma brucei; the causative agents of leishmaniasis, Chagas disease and African trypanosomiasis, respectively. Emphasis is given to secondary metabolites and crude extracts prepared from marine algae.

Influence of Apion sp. (Brentidae, Apioninae) stem-galls on induced resistance and leaf area of Diospyros hispida (Ebenaceae)

We addressed the influence of the stem galls induced by an unidentified species of Apion sensu lato (Brentidae, Apioninae) on the host plant, Diospyros hispida (Ebenaceae) leaf area and induced resistance against a Cecidomyiidae (Diptera) leaf galls. The study was performed in a cerrado vegetation in Serra do Cipó, southeastern Brazil. Although the number of leaves produced on galled and ungalled shoots did not differ statically (p>0.05), the presence of the apionid galls influenced the area of the leaves on the attacked shoots of D. hispida. Leaves on galled stems were approximately 50 percent smaller compared to leaves in healthy stems. The average of the cecidomyiid leaf galls successfully induced on healthy shoots was higher compared to galls successfully induced on shoots galled by the apionid. The same pattern was found for the abundance of hypersensitive reactions against the cedidomyiid gall induction. Therefore, the ability of the cecidomyiid to successfully induce galls was not influenced by the apionid galler.

Neste estudo verificamos a influência de galhas de ramos induzida por uma espécie não identificada de Apion sp. (Brentidae, Apioninae) sobre a área foliar da planta hospedeira Diospyros hispida (Ebenaceae) e na resistência induzida contra galhas de folhas de um Cecidomyiidae (Diptera). Este estudo foi conduzido em uma vegetação de cerrado na Serra do Cipó, sudeste do Brasil. Embora o número de folhas produzidas nos ramos galhados e não galhados não tenha diferido estaticamente (p>0,05), a presença das galhas de Apion sp. influenciou a área foliar nos ramos atacados de D. hispida. Folhas de ramos com galhas foram aproximadamente 50 por cento menores quando comparadas a folhas em ramos saudáveis. A média de galhas foliares do Cecidomyiideae que se formaram com sucesso em folhas de ramos saudáveis foi maior quando comparado à média de galhas bem sucedidas em folhas de ramos galhados pelo Apion sp.. O mesmo padrão foi encontrado para a abundância de reações hipersensibilidade contra a formação de galhas do cecidomyiídeo. Portanto, a habilidade do cecidomyiídeo de induzir galhas não foi influenciada pelas galhas de Apion sp..