Antiparasitic Activities of Compounds Isolated from Aspergillus fumigatus Strain Discovered in Northcentral Nigeria.

In this study, we explored a fungal strain UIAU-3F identified as Aspergillus fumigatus isolated from soil samples collected from the River Oyun in Kwara State, Nigeria. In order to explore its chemical diversity, the fungal strain UIAU-3F was cultured in three different fermentation media, which resulted in different chemical profiles, evidenced by LC-ESI-MS-based metabolomics and multivariate analysis. The methanolic extract afforded two known compounds, fumitremorgin C (1) and pseurotin D (2). The in vitro antiparasitic assays of 1 against Trypanosoma cruzi and Plasmodium falciparum showed moderate activity with IC50 values of 9.6 µM and 2.3 µM, respectively, while 2 displayed IC50 values > 50 µM. Molecular docking analysis was performed on major protein targets to better understand the potential mechanism of the antitrypanosomal and antiplasmodial activities of the two known compounds.

Can Crude Oil Exploration Influence the Phytochemicals and Bioactivity of Medicinal Plants? A Case of Nigerian Vernonia amygdalina and Ocimum gratissimum.

The Nigerian Niger-Delta crude oil exploration often results in spills that affect indigenous medicinal plant biodiversity, likely changing the phytochemical profile of surviving species, their bioactivity or toxicity. In crude oil-rich Kokori and crude oil-free Abraka, classic examples of indigenous plants occupying the medicine-food interface include Vernonia amygdalina (VAL) and Ocimum gratissimum leaves (OGL). These plants are frequently utilised during pregnancy and in anaemia. To date, no scientific investigation has been reported on the potential changes to the phytochemical or bioactivity of the study plants. To discuss the similarities and dissimilarities in antisickling bioactivity and phytochemicals in VAL and OGL collected from Kokori (VAL-KK and OGL-KK) and Abraka (VAL-AB and OGL-AB), in silico, in vitro and comparative UPLC-QTOF-MS analysis was performed. Nine unique compounds were identified in OGL-KK, which have never been reported in the literature, while differences in antisickling potentials were observed in VAL-KK, OGL-KK and, VAL-AB, OGL-AB. Our findings show that VAL-AB and OGL-AB are richer and more diverse in phytochemicals and displayed a slightly higher antisickling activity than VAL-KK and OGL-KK. Ligand-based pharmacophore modelling was performed to understand the potential compounds better; this study may provide a basis for explaining the effect of crude oil spills on secondary metabolites and a reference for further research.

Inhibition of the Quorum Sensing System, Elastase Production and Biofilm Formation in Pseudomonas aeruginosa by Psammaplin A and Bisaprasin.

Natural products derived from marine sponges have exhibited bioactivity and, in some cases, serve as potent quorum sensing inhibitory agents that prevent biofilm formation and attenuate virulence factor expression by pathogenic microorganisms. In this study, the inhibitory activity of the psammaplin-type compounds, psammaplin A (1) and bisaprasin (2), isolated from the marine sponge, Aplysinellarhax, are evaluated in quorum sensing inhibitory assays based on the Pseudomonas aeruginosa PAO1 lasB-gfp(ASV) and rhlA-gfp(ASV) biosensor strains. The results indicate that psammaplin A (1) showed moderate inhibition on lasB-gfp expression, but significantly inhibited the QS-gene promoter, rhlA-gfp, with IC50 values at 14.02 µM and 4.99 µM, respectively. In contrast, bisaprasin (2) displayed significant florescence inhibition in both biosensors, PAO1 lasB-gfp and rhlA-gfp, with IC50 values at 3.53 µM and 2.41 µM, respectively. Preliminary analysis suggested the importance of the bromotyrosine and oxime functionalities for QSI activity in these molecules. In addition, psammaplin A and bisaprasin downregulated elastase expression as determined by the standard enzymatic elastase assay, although greater reduction in elastase production was observed with 1 at 50 µM and 100 µM. Furthermore, the study revealed that bisaprasin (2) reduced biofilm formation in P. aeruginosa.

Heavy Metals, Proximate Analysis and Brine Shrimp Lethality of Vernonia amygdalina and Ocimum gratissimum Growing in Crude Oil-Rich Delta State, Nigeria.

Vernonia amygdalina (VA) and Ocimum gratissimum (OG) are among the most frequently consumed vegetables in Kokori and Abraka communities of Delta State, Nigeria. However, the continuous crude oil exploration and spillages in Kokori may threaten their safety for use as food and medicine. Twelve samples of VA and OG obtained from crude oil-rich and crude oil-free communities were comparatively analysed for proximate composition, heavy metals, and cytotoxicity. Data obtained were subjected to various multivariate statistical techniques, including principal component analysis (PCA), biplot, and analysis of variance (ANOVA), to investigate the correlations between the vegetables from the different communities and the effect of crude oil exploration and spill on plant biomass. Results obtained indicate a significant difference (p < 0.05) in the proximate composition of VA and OG and higher heavy metal content for VA from the crude oil-spill Kokori. Two VA collections from Kokori were exceptionally toxic to cellular crustaceans.