Plants of the Araceae family for malaria and related diseases: a review / Plantas da família Araceae para a malária e doenças relacionadas: uma revisão

ABSTRACTIn the current work we performed a review of the Araceae family species traditionally used to treat malaria and its symptoms. The aim is to reveal the large number of antimalarial Araceae species used worldwide and their great unexplored potential as sources of antimalarial natural products. The SciFinder Scholar, Scielo, PubMed, ScienceDirect and Google books search engines were consulted. Forty-three records of 36 species and 23 genera of Araceae used for malaria and symptoms treatment were found. The neotropical genera Philodendron Schott and Anthurium Schott were the best represented for the use in the treatment of malaria, fevers, liver problems and headaches. Leaves and tubers were the most used parts and decoction was the most common preparation method. The extracts of Araceae species inhibit the in vitro growth of the human malaria parasite, the Plasmodium falciparum Welch, and significant median inhibitory concentrations (IC50) for extracts of guaimbê-sulcado (Rhaphidophora decursiva (Roxb.) Schott), aninga (Montrichardia linifera (Arruda) Schott), Culcasia lancifolia N.E. Br. and forest anchomanes (Anchomanes difformis (Blume) Engl.) have been reported demonstrating the antimalarial and cytotoxicity potential of the extracts and sub-fractions. In the only report about the antimalarial components of this family, the neolignan polysyphorin and the benzoperoxide rhaphidecurperoxin presented strong in vitro inhibition of the D6 and W2 strains of Plasmodiumfalciparum (IC50 = 368-540 ng/mL). No live study about antimalarial activity in animal models has been conducted on a species of Araceae. More bioguided chemical composition studies about the in vitro and also thein vivo antimalarial activity of the Araceae are needed in order to enhance the knowledge about the antimalarial potential of this family.

RESUMONo presente trabalho realizamos uma revisão das espécies da família Araceae usadas para tratar malária e seus sintomas. O objetivo foi revelar o grande número de espécies da família usadas no mundo, assim como seu potencial como fontes de produtos naturais antimaláricos. Foram consultadas as plataformas de busca SciFinder Scholar, Scielo, PubMed, ScienceDirect e Google books. Encontramos quarenta e três registros de 36 espécies e 23 generos de Aráceas usadas para tratar malária e seus sintomas. Os generos neotropicais Philodendron Schott e Anthurium Schott foram os melhor representados, úteis para o tratamento da malária, febres, problemas hepáticos e dores de cabeça. Folhas e tubérculos foram as partes mais utilizadas, enquanto a decocção foi o método de preparo mais comum. Os extratos de espécies de Araceae inibem o crescimento in vitro do parasito da malária humana, Plasmodium falciparum Welch, e concentrações inibitórias medianas (CI50) significativas foram relatadas para extratos de guaimbê-sulcado (Rhaphidophora decursiva (Roxb.) Schott), aninga (Montrichardia linifera (Arruda) Schott), Culcasia lancifoliaN.E. Br. e anchomanes do mato (Anchomanes difformis (Blume) Engl.), demonstrando o potencial antimalárico e citotóxico de extratos e subfrações. No único relato sobre os componentes antimaláricos dessa família, a neolignana polisiforina e o benzoperóxido rafidecurperoxina apresentaram forte inibição das cepas D6 e W2 de Plasmodiumfalciparum in vitro (CI50 = 368-540 ng/mL). Nenhum estudo sobre a atividade antimalárica in vivo em modelo animal foi realizado com espécies da família Araceae. Mais trabalhos biomonitorados pela composição química sobre a atividade antimalárica in vitro, assim como estudos in vivo, são necessários para aprofundar os conhecimentos sobre potencial antimalárico da familia.

The potential of secondary metabolites from plants as drugs or leads against protozoan neglected diseases - part I

Infections with protozoan parasites are a major cause of disease and mortality in many tropical countries of the world. Diseases caused by species of the genera Trypanosoma (Human African Trypanosomiasis and Chagas Disease) and Leishmania (various forms of Leishmaniasis) are among the seventeen "Neglected Tropical Diseases" (NTDs) defined as such by WHO due to the neglect of financial investment into research and development of new drugs by a large part of pharmaceutical industry and neglect of public awareness in high income countries. Another major tropical protozoan disease is malaria (caused by various Plasmodium species), which -although not mentioned currently by the WHO as a neglected disease- still represents a major problem, especially to people living under poor circumstances in tropical countries. Malaria causes by far the highest number of deaths of all protozoan infections and is often (as in this review) included in the NTDs. The mentioned diseases threaten many millions of lives world-wide and they are mostly associated with poor socioeconomic and hygienic environment. Existing therapies suffer from various shortcomings, namely, a high degree of toxicity and unwanted effects, lack of availability and/or problematic application under the life conditions of affected populations. Development of new, safe and affordable drugs is therefore an urgent need. Nature has provided an innumerable number of drugs for the treatment of many serious diseases. Among the natural sources for new bioactive chemicals, plants are still predominant. Their secondary metabolism yields an immeasurable wealth of chemical structures which has been and will continue to be a source of new drugs, directly in their native form and after optimization by synthetic medicinal chemistry. The current review, published in two parts, attempts to give an overview on the potential of such plant-derived natural products as antiprotozoal leads and/or drugs in the fight against NTDs.