Bridelia species have been used in traditional African medicine for the management of diverse human ailments. In the current work, the detailed phytochemical profiles of the extracts of the stem bark of B. speciosa were evaluated and the antioxidant and enzyme inhibitory properties of the extracts were assessed. The anti-bacterial and anti-mycotic effects of the extracts were evaluated against selected pathogen strains. Additionally, the anti-proliferative effects were studied on the liver cancer HepG2 cell line. Finally, the putative protective effects were assessed on isolated rat liver that was challenged with lipopolysaccharide (LPS). The results revealed the presence of 36 compounds in the ethyl acetate extract, 44 in the methanol extract, and 38 in the water extract. Overall, the methanol extract showed the highest antioxidant activity, particularly in LPS-stimulated rat liver. Additionally, this extract exerted the highest antimycotic effect on C. albicans, whereas the water extract showed a promising anti-proliferative effect on liver cancer HepG2 cells. The methanol extract was also the most active as enzyme inhibitor, against acetylcholinesterase and butyrylcholinesterase. The current study appraises the antioxidant and enzyme inhibition properties of B. speciosa methanol extract and showed that this specie could be a promising source of biologically active phytochemicals, with potential health uses.

Anisakiasis is a human parasitic infection of the gastrointestinal tract that can cause severe abdominal pain, malnutrition, and vomiting. This parasitosis is mainly caused by larvae of the nematode Anisakis simplex, that reach the intestine through the consumption of raw and undercooked seafood, namely fish and cephalopods. Generally, it is undetected, but can sometimes be responsible for severe allergic reactions, namely anaphylaxis, caused by the production of immunoglobulin E in response to chemicals released by the dead larvae in the intestine. To date, no effective drug has been found against this digestive parasitosis and common anthelmintic treatments seem not be active against A. simplex. Essential oils (EOs) present a still fairly unexplored source for natural products with activity towards this parasite. The present work reviews the available literature on EOs tested in vitro against Anisakis nematodes, and compiles the EO composition and activity of the most active.

Over one dozen plant species were used as sources for the active EOs, mainly from Asteraceae, Lamiaceae, Apiaceae and Myrtaceae families. The lowest half maximal lethal concentrations (LC₅₀) were reported for Origanum syriacum and O. compactum EOs, both rich in the monoterpenoid carvacrol (83% and 50%, respectively. The EOs extracted from Tagetes minuta and Nepeta cataria were reported to be the fastest acting, with half maximal lethal times (LT₅₀) under 4 h, and were rich in the oxygenated monoterpene geraniol (55%) and the monoterpenic hydrocarbons β-ocimene (36%) and limonene (27%), respectively. Given their complex chemical composition, additive, synergistic and antagonistic interactions between EO compounds can be responsible for EO activity against this parasite.

A deeper analysis of the chemical structures active against Anisakis, and the nature of their interactions can be possible with further studies on this parasitosis.

The incidence of chronic wounds (CW) is growing at an accelerated rate around the world, becoming a huge burden on healthcare and social systems. CW are characterized for failing to progress through the orderly phases of the healing process, establishing in a self-perpetuating inflammatory stage getting predisposed to infections, resulting in long-term morbidity and mortality. To address this problem, wound dressings with a new intricated nano-architecture and functionalized with active biomolecules are being developed to treat CW. The introduction of peptides with renown antimicrobial capacities, as pexiganan (or MSI-78), which display a broad spectrum of antibacterial activity and capacity to reduce bacterial resistance, has been considered a viable solution. Tiger 17, a not so explored peptide with improved regenerative potential is also being investigated to unveil its antimicrobial potential so far unknown. In this study, combinations of poly(vinyl alcohol) (PVA) and cellulosic compounds, such as cellulose acetate (CA) and cellulose nanocrystalline (CNC), were processed via electrospinning to give rise to porous, highlight intricate and flexible, biocompatible, biodegradable, and mechanically stable mats and, then, modified with combinations of pexiganan and Tiger 17. PVA/CA and PVA/CNC mats were prepared at different ratios and submitted to crosslinking process to avoid their instant solubilization in aqueous media. Antimicrobial efficacy of pexiganan and Tiger 17 was evaluated against Pseudomonas aeruginosa. The biomolecules were initially screened for their antibacterial efficacy by the determination of minimal inhibitory concentrations (MICs). Mats were modified with pexiganan at 2xMIC (60 µg/mL) and with Tiger 17 at twice the concentration required to induce regenerative effects (40 µg/mL). The Mal-PEG2-OH spacer was used as a binding agent. Data revealed the ability of the peptide-modified surfaces to fight P. aeruginosa infection above the unaltered mats, demonstrating the potential of this strategy for CW care.

Natural products (NPs), being evolutionary selected over millions of years to bind to biological macromolecules, remain an important source of inspiration for medicinal chemists even after the advent of efficient drug discovery technologies such as combinatorial chemistry and high-throughput screening. Thus, there is a strong demand for efficient and user-friendly computational tools that allow to analyze large libraries of NPs. In this context, we present NP Navigator – a free, intuitive online tool for visualization and navigation through the chemical space of NPs and NP-like molecules^[1] (https://infochm.chimie.unistra.fr/npnav/chematlas_userspace ). It is based on the hierarchical ensemble of more than 200 Generative Topographic Maps(GTM)^[2], featuring NPs from the COlleCtion of Open NatUral producTs (COCONUT), bioactive compounds from ChEMBL and commercially available molecules from ZINC. NP Navigator allows to efficiently analyze different aspects of NPs - chemotype distribution, physicochemical properties, reported and/or predicted biological activity and commercial availability of NPs. Users are welcome not only to browse through hundreds of thousands of compounds from ZINC, ChEMBL and COCONUT but also project a several external molecules that play the role of “chemical trackers” allowing to trace particular chemotypes in the NP chemical space and detect analogs of the compound of interest.

[1] Y. Zabolotna, P. Ertl, D. Horvath, F. Bonachera, G. Marcou, A. Varnek, NP Navigator: a New Look at the Natural Product Chemical Space, 2021.
[2] C. M. Bishop, M. Svensén, C. K. I. Williams, Neural Comput. 1998, 10, 215-234.

According to The Organization for Economic Cooperation and Development (OECD), 2.4 million people in Europe, North America and Australia may die in the next 30 years from infections caused by resistant microorganisms. S. aureus – a opportunistic pathogen resistant to multiple antibiotics – induced infections are among the most prevalent bacterial infections, being on the front of the line of the World Health Organization (WHO) concerns. In this study, we report the production of biodegradable microfibers composed of sodium alginate (SA) and gelatin (GN), via wet-spinning technique, and their subsequent functionalization via adsorption with Nisin Z. Nisin Z is an antimicrobial peptide which possess great antibacterial activity (mainly against Gram-positive bacteria) and low toxicity in humans, thus being a great candidate for the production of scaffolds with S. aureus eradication ability for infected wounds. SA/GN microfibers were successfully extruded at a 70/30% v/v polymer ratio, within a calcium chloride (CaCl₂) 2wt% coagulation bath. SA-free fibers were obtained through chemical modification (PBS concentrated solutions and subsequently, SAGN and SA-free fibers were crosslinked with glutaraldehyde (labeled as SAGNCL and GNCL, respectively). Finally, Nisin Z was functionalized onto the fibers at an average concentration of 178µg/mL. Fibers were characterized via Fourier transform infrared spectroscopy, thermal analysis and brightfield microscopy. Nisin Z degradation/release profiles (SBF, 28 days) were assessed. Antibacterial activity against S. aureus was detected via time-kill kinetics assessments. SAGNCL and GNCL loaded microfibers were capable of inhibit the grow of S. aureus up to 99% after 48 h of culture. The SA and SAGN loaded microfibers were not as effective, losing their action after 6 h. Bacteria elimination was consistent with the release kinetics of Nisin Z from the fibers. Overall, data revealed the potential of Nisin Z in fighting S. aureus-induced infections, while loaded onto biodegradable crosslinked polymeric scaffolds.