In vitro antiprotozoal activity and cytotoxicity of extracts and fractions from the leaves, root bark and stem bark of Isolona hexaloba

Models for cytotoxicity screening of antileishmanial drugs: what has been done so far?

A growing number of studies have demonstrated the in vitro potential of an impressive number of antileishmanial candidates in the past years. However, the lack of uniformity regarding the choice of cell types for cytotoxicity assays may lead to uncomparable and inconclusive data. In vitro assays relying solely on non-phagocytic cell models may not represent a realistic result as the effect of an antileishmanial agent should ideally be presented based on its cytotoxicity profile against reticuloendothelial system cells. In the present review, we have assembled studies published in the scientific literature from 2015 to 2021 that explored leishmanicidal candidates, emphasising the main host cell models used for cytotoxicity assays. The pros and cons of different host cell types as well as primary cells and cell lines are discussed in order to draw attention to the need to establish standardised protocols for preclinical testing when assessing new antileishmanial candidates.

Natural Products from Annonaceae as Potential Antichagasic Agents

Chagas disease, a neglected tropical disease, is endemic in 21 Latin American countries and particularly prevalent in Brazil. Chagas disease has drawn more attention in recent years due to its expansion into non-endemic areas. The aim of this work was to computationally identify and experimentally validate the natural products from an Annonaceae family as antichagasic agents. Through the ligand-based virtual screening, we identified 57 molecules with potential activity against the epimastigote form of T. cruzi. Then, 16 molecules were analyzed in the in vitro study, of which, six molecules displayed previously unknown antiepimastigote activity. We also evaluated these six molecules for trypanocidal activity. We observed that all six molecules have potential activity against the amastigote form, but no molecules were active against the trypomastigote form. 13-Epicupressic acid seems to be the most promising, as it was predicted as an active compound in the in silico study against the amastigote form of T. cruzi, in addition to having in vitro activity against the epimastigote form.

The genus Psiadia: Review of traditional uses, phytochemistry and pharmacology

ETHNOPHARMACOLOGICAL RELEVANCE

The genus Psiadia Jacq. ex. Willd. belongs to the Asteraceae family and includes more than 60 species. This genus grows in tropical and subtropical regions, being especially well represented in Madagascar and the Mascarene Islands (La Réunion, Mauritius and Rodrigues). Several Psiadia species have been used traditionally for their medicinal properties in Africa and the Mascarene Islands. Based on traditional knowledge, various phytochemical and pharmacological studies have been conducted. However there are no recent papers that provide an overview of the medicinal potential of Psiadia species. Therefore, the aim of this review is to provide a comprehensive summary of the botany, phytochemistry and pharmacology of Psiadia and to highlight the gaps in our knowledge for future research opportunities.

MATERIALS AND METHODS

The available information on traditional uses, phytochemistry and biological activities of the genus Psiadia was collected from scientific databases through a search using the keyword 'Psiadia' in 'Google Scholar', 'Pubmed', 'Sciencedirect', 'SpringerLink', 'Web of Science', 'Wiley' and 'Scifinder'. Additionally, published books and unpublished Ph.D. and MSc. dissertations were consulted for botanical information and chemical composition.

RESULTS

Historically, species of the genus Psiadia have been used to treat a wide range of ailments including abdominal pains, colds, fevers, bronchitis, asthma, rheumatoid arthritis, skin infections and liver disorders among others. Phytochemical works led to the isolation of flavonoids, phenylpropanoids, coumarins and terpenoids. Furthermore, phytochemical compositions of the essential oils of some species have been evaluated. Crude extracts, essential oils and isolated molecules showed in vitro pharmacological activities, such as antimicrobial, anti-viral, anti-inflammatory, antiplasmodial and antileishmanial activities. Crude extracts of Psiadia dentata and Psiadia arguta have specifically been found to be potentially useful for inhibition of growth of Plasmodium falciparum. However, pharmacological data on this particular genus is quite limited. Further research is necessary to determine the active compounds and the underlying mechanisms.