Natural products are generally ingested as part of traditional herbal decoctions or in the current diet. However, in natural product research, the bioavailability of secondary metabolites is often poorly investigated. In this work, a systematic study was carried out in order to highlight the physicochemical parameters that mainly influence the passive intestinal absorption of natural products. For this, a representative set of natural products including alkaloids, coumarins, flavonoid aglycones and glycosides, and carboxylic acids was selected and their physicochemical properties were predicted using relevant Volsurf+ descriptors. The chemical space obtained with this unbiased method was then correlated with experimental passive intestinal permeability data, which highlighted the main influence of lipophilicity, global hydrophilicity, size, and the ionisation state on passive intestinal absorption of natural products. Since the pH range encountered in the intestine is wide, the infl...

Endophytic fungi associated with medicinal plants are a potential source of novel chemistry and biology. Metabolomic tools were successfully employed to compare the metabolite fingerprints of solid and liquid culture extracts of endophyte Curvularia sp. isolated from the leaves of Terminalia laxiflora. Natural product databases were used to dereplicate metabolites in order to determine known compounds and the presence of new natural products. Multivariate analysis highlighted the putative metabolites responsible for the bioactivity of the fungal extract and its fractions on NF-κB and the myelogenous leukemia cell line K562. Metabolomic tools and dereplication studies using high-resolution electrospray ionization mass spectrometry directed the fractionation and isolation of the bioactive components from the fungal extracts. This resulted in the isolation of N-acetylphenylalanine (1) and two linear peptide congeners of 1: dipeptide N-acetylphenylalanyl-L-phenylalanine (2) and tripepti...

The scientific interest in (+)-usnic acid has grown because of its antitumor, cytotoxic, and antimicrobial activities as well as weight loss. However, overuse of usnic acid has been related with severe hepatotoxicity, making its use questionable. In this study, we decided to expand the knowledge of usnic acid biological activities by characterizing its effects on the mammalian myocardium as a potential pharmacological target. Usnic acid was isolated from samples of Cladonia substellata and submitted to chemical characterization. Molecular inclusion complexes of usnic acid with hydroxypropyl β-cyclodextrin were prepared to improve its water solubility. The effects of usnic acid on the atrial contractility and Ca2+ influx were carried out in the left atrium of guinea pigs and the effect of usnic acid on the L-type Ca2+ current was performed in rat ventricular cardiomyocytes enzymatically isolated. To evaluate the membrane integrity of cells subjected to usnic acid, we used histologica...

Three new abietane-type diterpenoids, plectranthroyleanones A – C (1 – 3), together with five known compounds (4 – 8) were isolated from the methanol extract of the whole plant of Plectranthus africanus using column chromatography techniques. The structures of the new compounds were elucidated using a combination of 1D and 2D NMR and HRESIMS analyses. Compound 1 exhibited weak activities with minimal inhibitory concentration values of 75 µg/mL against gram-positive bacteria, Bacillus subtilis and Staphylococcus aureus, and 150 µg/mL against two gram-negative bacteria, Pseudomonas aeruginosa and Klebsiella pneumoniae, respectively, while 2 and 3 had moderate antibacterial activity against K. pneumoniae with a minimal inhibitory concentration value of 37.5 µg/mL.

Resumen Context: Garcinia kola seeds are widely used in Congolese traditional medicine to treat uncomplicated malaria. While the ethanolic extract of these seeds (GK) is reputed for oral antimalarial activity, some of its constituents have shown poor water solubility, which might compromise further phytopharmaceutical developments. Aims: To develop a self-nanoemulsifying drug delivery system (SNEDDS) for oral delivery of GK, since SNEDDS are promising vehicles for enhancing drug product solubility. Methods: GK was loaded into liquid SNEDDS (solution and suspension) and solid SNEDDS (S-SNEDDS), and the resultant formulations were characterized using dynamic light scattering and electron microscopy. The antimalarial activity of SNEDDS (200 mg/kg × 4 days, oral) was evaluated in Plasmodium berghei-infected mice using a conventional fourday suppressive test. Results: The characterization of SNEDDS formulations revealed the presence of nanosized structures of spherical morphology and neg...

The objective of this study was to validate scientifically the antimalarial effectiveness and safety of A. senegalensis. Ethanolic crude extracts of Annona senegalensis growing in Democratic Republic of the Congo were evaluated for the inhibitory effects on two malaria parasites strains (P. falciparum FcM29 & P. yoelii subsp nigeriensis) and cytotoxicity towards leukaemia P-388 cell lines. Results indicate that, the antiplasmodial activities of tested plant extracts are moderate in vitro and weak in vivo. While the leaves crude extract displayed toxic effect towards P-388 cells. So, the wide use of this medicinal plant in Congolese Folk Medicine as antimalarial herbal could constitutes a great risk of population poisoning. of the Congo. INTRODUCTION Malaria is an infectious disease caused by a protozoan of the phylum: Apicomplexa, class: Sporozoa, subclass: Coccidia, suborder: Haemosporina, family: Plasmodidae, genus Plasmodium and transmitted by the female mosquito of the genus Ano...