Multidrug-resistant (MDR) Gram-negative bacteria remain a global public health issue due to the barrier imposed by their outer membrane and their propensity to form biofilms. It is becoming imperative to develop new antibacterial strategies. In this context, this study aims to evaluate the antibacterial efficacy of Origanum vulgare essential oil (OEO), alone and in combination with antibiotics, as well as its antibiofilm action against multidrug-resistant Gram-negative strains. OEO components were identified by gas chromatography-mass spectrometry (GC-MS), and antibacterial activity was assessed using the agar diffusion test and the microdilution method. Interactions between OEO and antibiotics were examined using the checkerboard method, while antibiofilm activity was analyzed using the crystal violet assay. Chemical analysis revealed that carvacrol was the major compound in OEO (61.51%). This essential oil demonstrated activity against all the tested strains, with inhibition zone diameters (IZDs) reaching 32.3 ± 1.5 mm. The combination of OEO with different antibiotics produced synergistic and additive effects, leading to a reduction of up to 98.44% in minimum inhibitory concentrations (MICs). In addition, this essential oil demonstrated an ability to inhibit and even eradicate biofilm formation. These results suggest that OEO could be exploited in the development of new molecules, combining its metabolites with antibiotics.

Carthamus caeruleus L. is traditionally used in Algerian medicine, particularly for burn treatment, but its therapeutic potential remains insufficiently studied. This study aimed to evaluate the antioxidant and anti-inflammatory properties of the root aqueous extract, and to perform phytochemical characterization to identify its bioactive compounds. Phytochemical analysis was conducted using spectrophotometry and reverse-phase high-performance liquid chromatography (RP-HPLC). The antioxidant potential was assessed through various assays, including ferric reducing antioxidant power (FRAP), total antioxidant capacity (TAC), DPPH radical scavenging, hydroxyl radical scavenging, ferrous ion chelation, and hydrogen peroxide decomposition. Anti-inflammatory activity was evaluated using membrane stabilization, protein denaturation, and membrane peroxidation assays. The extract exhibited moderate levels of polyphenols, flavonoids, and condensed tannins, quantified as 21.19 ± 0.37 mg GAE/g, 0.72 ± 0.013 mg QE/g, and 27.28 ± 1.04 mg TAE/g of dry extract, respectively. RP-HPLC analysis identified 22 phytochemical compounds, primarily phenolic acids, flavonoids, and tannins, with orientin and vanillin as the major constituents. The extract demonstrated significant antioxidant activity, with moderate efficacy in TAC and FRAP assays (IC₅₀ values of 5405.1 ± 4.42 and 1132.35 ± 4.97 µg/mL, respectively). Notable activities included DPPH and hydroxyl radical scavenging (34.43 ± 4.83 and 512.81 ± 9.46 µg/mL, respectively), ferrous ion chelation (2462.76 ± 1.38 µg/mL), lipid peroxidation inhibition (22.32 ± 3.31%), and hydrogen peroxide decomposition (263.93 ± 7.87 µg/mL). Additionally, the extract stabilized erythrocyte membranes under osmotic, thermal, and oxidative stress conditions (98.13 ± 0.15%, 70 ± 1.27%, and 89 ± 0.87%, respectively), inhibited ovalbumin denaturation (81.05 ± 2.2%), and protected against lipid peroxidation in brain homogenates (69.25 ± 0.89%). These findings support the traditional therapeutic applications of C. caeruleus and highlight its potential as a source of antioxidant and anti-inflammatory agents.

This study aimed to evaluate the anti-inflammatory properties of Carthamus caeruleus L. root juice (CRJ), which is used in the traditional medicine of Algeria. The product was characterized by colorimetric assays (total polyphenols, flavonoids, and tannins) and by RP-HPLC-DAD analysis. Experiments were conducted in vitro to assess the ability of CRJ to stabilize human erythrocyte membranes under various stress conditions and inhibit albumin denaturation, a process linked to inflammation. An in silico study was also performed to investigate the inhibitory effects on cyclooxygenase-2 (COX-2) and assess the phenolic constituents with the highest activity. Moderate levels of polyphenols, flavonoids, and tannins were assessed; among these, 22 compounds were identified via chromatographic analysis. While present at low concentrations, some of these compounds, including myricetin, luteolin, and quercetin, are known to exhibit bioactivity at micromolar levels. CRJ provided erythrocyte membranes with notable protection against disruption caused by hypotonic NaCl solutions (protection levels of 90.51%, 87.46%, and 76.87% at NaCl concentrations of 0.7%, 0.5%, and 0.3%, respectively), heat stress (81.54%), and oxidative damage from HClO (75.43%). Additionally, a protection of 61.5% was observed against albumin denaturation. Docking analysis indicated favorable COX-2 binding for myricetin, luteolin, and quercetin. In conclusion, the root juice derived from C. caeruleus demonstrated potential anti-inflammatory activity in vitro and in silico. However, further studies, including in vivo investigations, are necessary to confirm efficacy and fully elucidate the mechanisms of action.

Avian pathogenic Escherichia coli (APEC) represents a major challenge for the poultry industry, causing significant economic losses. This problem is exacerbated by the misuse use of antibiotics in Veterinary Medicine, leading to the emergence of resistant strains and thus creating a significant risk to Public Health. This study, carried out on 38 poultry farms in Algeria, involved the collection of 200 samples for the isolation of E. coli strains. The resistance of these strains to frequently used antibiotics was assessed using the agar diffusion method. Multiple Correspondence Analysis (MCA) was used to determine potential risk factors. The obtained results revealed that E. coli was present in 30% of samples. Alarming levels of resistance were observed against Tetracycline (81.6%), Ampicillin (78.3%), Ciprofloxacin (68.3%) and Nalidixic acid (60%). Stressful environmental conditions in poultry houses, such as temperature variations, high humidity, poor ventilation and stocking density were identified as key factors in the development of avian colibacillosis. In conclusion, the current study highlights the urgent need to strictly monitor and regulate the use of antibiotics in Veterinary Medicine and improve animal welfare in order to minimize the risk it pose to Public Health originated in the farms. In addition, it is essential that farmers maintain optimal environmental conditions in chicken rearing.