Mohamed Haddad

Ethnopharmacological relevance Spermacoce stachydea (Rubiaceae) is traditionally used for malaria treatment, yet its phytochemical composition, antioxidant properties, antiplasmodial activity, and safety profile remain insufficiently characterised. This study aimed to provide a comprehensive preclinical validation of its ethnomedicinal use.Methods The whole-plant methanolic extract was profiled by UHPLC-HRMS and GC–MS. Total phenolic (TPC), flavonoid (TFC), and condensed tannin (CTC) contents were quantified, and antioxidant capacity was assessed by DPPH, ABTS, FRAP, and ORAC assays. Antiplasmodial activity was evaluated in vitro against Plasmodium falciparum and in vivo in P. berghei ANKA-infected NMRI mice using suppressive, curative, and prophylactic models. Host-protective effects and safety were assessed through physiological, haematological, biochemical, and histopathological analyses in accordance with OECD guidelines.Results Phytochemical profiling revealed a diverse array of bioactive metabolites including flavonoids, terpenoids, coumarins, iridoids, alkaloids, and polyphenols. The extract exhibited a flavonoid-dominant phenolic profile (TPC: 33.99 ± 0.07 mg GAE/100 mg; TFC: 7.57 ± 0.03 mg QE/100 mg) and strong DPPH radical scavenging activity (774 ± 3.9 µmol AAE/g), comparable to Trolox and superior to quercetin. In vitro antiplasmodial activity was significant (IC₅₀ = 6.30 ± 0.13 µg/mL) with negligible haemolysis ( 5000 mg/kg) and 2000 mg/kg/day (subacute; NOAEL > 2000 mg/kg/day). The extract exhibited low toxicity, with an oral LD₅₀ > 5000 mg/kg and a subacute NOAEL of 2000 mg/kg.Conclusion S. stachydea demonstrated significant antiplasmodial, antioxidant, and host-protective activities with a favourable safety profile, validating its traditional use in malaria management and supporting its potential as a source of multitarget antimalarial compounds.

Food safety remains a critical challenge in Nigeria due to rapid urbanization and weak regulatory enforcement. This systematic review synthesizes empirical evidence from 2015 to 2025 to characterize food contaminant profiles and associated human health risks in Nigeria. Following PRISMA guidelines, a systematic search was conducted across five electronic databases. Analytical studies reporting quantitative data on chemical and biological contaminants in Nigerian food matrices were included. Risk of bias was assessed using a modified tool for cross‐sectional analytical studies. Forty‐one studies met the inclusion criteria. Contaminants included microbial hazards (43.9%), heavy metals (26.8%), pesticides (12.2%), and organic chemical pollutants. Heavy metal studies reported exceedances of FAO/WHO limits, with chromium and nickel driving cancer risks above the safety threshold. Mycotoxin (aflatoxin) contamination was often reported in artisanal and poorly stored foods, with levels more than threefold above regulatory limits. Ready‐to‐eat foods exhibited significant microbial loads, with a high prevalence of multidrug‐resistant pathogens. Nigerian consumers face a “dual burden” of chronic chemical exposure and acute microbial hazards. Urgent policy interventions are required to strengthen market surveillance, enforce antimicrobial stewardship in agriculture, and develop targeted risk communication for vulnerable subpopulations, particularly children.

Combined mycotoxin contamination patterns with fungal sources were studied in maize, rice, and peanuts from Beninese markets, to evaluate population exposure by staple foods and to characterise its Fusarium species. An initial survey of 95 maize samples in 2022 showed fumonisins contamination up to 9900 μg/kg, with 20% exceeding the FDA advisory level and the EU maximum level of 2000 μg/kg for direct human consumption. Subsequent analysis in 2024 of another 69 samples also on aflatoxins confirmed the previous findings, with co-occurrence in many samples. Fungal characterisation from maize, sorghum and millet identified F. verticillioides predominantly in maize and F. andiyazi in sorghum. Metabolomic analysis demonstrated that F. verticillioides isolates produced multiple fumonisins, while F. andiyazi produced only fusarins. These findings connect contamination patterns to their fungal sources in cereals and highlight the importance of ongoing surveillance for regional food safety, particularly given climate change impacts on fungal growth.

Mycotoxin contamination of staple foods represents a significant public health concern, particularly in countries lacking regulatory frameworks. This study aimed to assess mycotoxin contamination in maize, cowpeas and rice from local markets across Mauritania, using three detection methods (Charm II, ELISA and immunochromatographic tests). Samples were collected from 14 markets in six cities to analyse the presence of aflatoxins, ochratoxins, zearalenone and fumonisins. Preliminary results revealed significant contamination in cowpeas (64% positive for aflatoxins) and maize samples (fumonisins levels up to 50 times the EU limits in Nouakchott and Rosso markets). Rice samples showed minimal contamination across all tested mycotoxins. The obtained results highlight the need for monitoring and regulation of mycotoxin contamination in Mauritania, particularly considering climate change impacts on mycotoxin production and associated health risks.

This study investigates the mechanisms underlying colour production in the family Coccinellidae, focusing on two model species: A. bipunctata (L) and C. quatuordecimguttata (L) . In this family, colours have traditionally been attributed primarily to pigments such as carotenoids and melanins. We propose an alternative perspective, considering the elytra as an integrated optical medium whose optical properties result from both its architectural design and the properties of its constituent materials, including matrix and pigments. In the present work, several methods were used, ranging from optical and electron microscopies, light-based techniques, to LC-HRMS analyses. Through local pigment analyses, microstructural examination of elytra, and modelling of interaction of elytra with light, we show that, while pigments are central to patterning and contribute to colour, overall colour also results from one or more physical mechanisms that may operate simultaneously. In the light of these results, we assume that the complex and diverse colouration in the Coccinellidae can only be elucidated by considering the interplay of pigments and the optical properties of the elytron cuticle.

Background: The gut microbiota of insects represents an underexplored reservoir of bioactive compounds with potential antimicrobial applications. This study is aimed at identifying antimicrobial compounds from fungi associated with the gut microbiota of Hermetia illucens (black soldier fly) larvae active against Salmonella enterica serovar Pullorum, an important poultry pathogen. Methods: Fungi isolated from H. illucens larval gut were screened for antimicrobial activity against S. enterica serovar Pullorum. The active fungus was identified through molecular analysis of ITS, benA, and CaM regions. Ethyl acetate extract from the fungal culture was assessed for antimicrobial activity, followed by bioguided fractionation using preparative and semipreparative chromatography. Active fractions were analyzed using UHPLC/HRMS, and putative compound identification was performed through mass spectrometry and molecular networking. Result: Aspergillus chevalieri was identified as active against S. enterica serovar Pullorum, with the ethyl acetate extract exhibiting moderate antimicrobial activity (MIC = 4.00 mg/mL; IC ₅₀ = 3.00 ± 0.58 mg/mL). Bioguided fractionation resulted in several active fractions. UHPLC/HRMS analysis putatively annotated 10 compounds, previously shown to be bioactive, including diketopiperazines (Neoechinulin A and echinulin), peptide derivatives (cyclo(L‐Tyr‐L‐Pro) and N ‐acetyltyramine), a benzofuran derivative, an isocoumarin (diaporthin), a flavin (lumichrome), an aminopurine (isopentenyladenine), and two diterpenoids (4‐deoxyphorbol‐13‐acetate and austinoneol). Conclusion: This study represents the first report of A. chevalieri associated with H. illucens larvae and demonstrates its potential as a source of antimicrobial compounds against S. enterica serovar Pullorum. The identified bioactive compounds provide promising leads for the development of new antimicrobial agents for poultry health.

Fusarium verticillioides is a prevalent plant pathogenic fungus known to produce harmful mycotoxins, including fumonisins and emerging toxins. This study aimed to investigate the influence of substrate on the temporal patterns of mycotoxin biosynthesis by F. verticillioides, employing a combined OSMAC (One Strain‐Many Compounds) strategy and metabolomics approach. The fungus was cultured under various media conditions, and samples were collected over time. LC–MS/MS analyses and a dereplicative workflow were used to profile the secondary metabolite production, focusing on mycotoxins. The results demonstrated that modifying the culture conditions led to significant variations in fungal growth and the nature and relative concentrations of mycotoxins produced. Corn meal agar (CMA) medium was favorable for fumonisins A₁ and B₁, while malt extract agar (MEA) favored fumonisins A₂ and B₂. The study also identified the production of other mycotoxins related compounds as fusarins, bikaverin derivatives and fumonisins analogs, under different growth conditions. This study highlights the potential of combining OSMAC and metabolomics to unravel the substrate‐dependent and time‐dependent variations in mycotoxin biosynthesis by F. verticillioides. The insights gained provide a better understanding of the ecophysiology of this fungus and the occurrence of its mycotoxins, which can inform targeted mitigation strategies to ensure food and feed safety.