Kinetics of Inhibition of Xanthine Oxidase by Lycium arabicum and its Protective Effect against Oxonate- Induced Hyperuricemia and Renal Dysfunction in Mice

Purpose: To evaluate the in vitro antioxidant activity of some flavonoids isolated from Varthemia iphionoids aqueous methanol extract.Methods: A portion (330 g) of the aqueous methanol extract of Varthemia iphionoids was adsorbed onto 200 g of S silica gel (70 - 230 mesh) and then loaded onto a column of S silica gel (70 - 230 mesh, 100 g). The column was packed with chloroform and eluted with chloroform-methanol mixtures of increasing polarity. Column chromatography purification (silica gel, 400 mesh) and thin-layer chromatography (TLC) or recrystallization yielded 5 compounds subsequently identified by nuclear magnetic resonance (NMR) and mass spectroscopy (MS).Results: The antioxidant activities of five identified flavonoids: Kumatakillin (1), Penduletin (2), Jeceidine (3), 6-Methoxy isokaemfride (4), and 3,3’-Di-O-methyl quercetin (5) were determined. The results indicated that compound 3 exhibited the best scavenging activity against DPPH radical and H2O2 comparable to that of quercetin as standard. All compounds had the ability to prevent the oxidation of β- carotene. In anti-hemolytic assay, the five compounds gave HT50 higher than vitamin C. The best protection activity of erythrocytes membrane was recorded with compound 2 (HT50 = 60.14 ± 0.72 min). Moreover, all compounds had significantly increased blood clotting time, and among them, compounds 1, 2, and 3 exhibited significantly increased thrombolytic activity compared to the control (***p < 0.001).Conclusion: These results indicate that Varthemia iphionoids has good antioxidant activities but further studies on the plant extract are required.

The antibacterial activity of 18 phenolic compounds, including flavonoids and phenolic acids, against organisms of Escherichia coli, Klebsiella pneumoniae, and Proteus vulgaris that are resistant to several drugs was assessed in this study using the agar diffusion method. The strain’s strong resistance was confirmed by antibiotic susceptibility testing, which used fourteen drugs and only found inhibition zones for five of them. Out of the polyphenols, four compounds were effective against P. vulgaris, five against K. pneumoniae, and twelve against E. coli bacteria. The greatest inhibitory zone (18.75 ± 0.25 mm) against E. coli was shown by propyl gallate, an ester of gallic acid. Activity was significantly impacted by structural changes. Propyl substitution increased antibacterial activities across all strains, while methoxy substitution decreased them. The antibacterial effectiveness was reduced by the hydroxylation of flavonoids and the C3–C4 dihydroxylation of cinnamic acid. Propyl gallate primarily had antagonistic effects, while combination experiments demonstrated additive, synergistic, and antagonistic interactions. Propyl gallate (ΔG = −7.5 kcal/mol) exhibited substantial binding affinities with TEM-1 and NDM-1 β-lactamases via hydrogen and hydrophobic interactions, according to molecular docking. These results demonstrate propyl gallate as a viable antibacterial adjuvant option and validate the structure–activity relationship of phenolic compounds.

Background: The vaginal microbiota of healthy women is predominantly composed of lactic acid bacteria (LAB), particularly species from the lactobacilli group, which contribute to the maintenance of vaginal health through multiple protective mechanisms. Objectives: In the present study, vaginal LAB isolated from healthy premenopausal Algerian women were evaluated for their probiotic potential. Methods: A total of 259 LAB isolates were initially screened for antimicrobial activity against vaginal pathogens, among which 164 strains exhibited inhibitory effects. Based on antimicrobial capacity and biofilm formation ability, 38 strains were selected for further characterization. A refined subset of 15 strains belonging to Lactiplantibacillus (Lpb.) plantarum, Limosilactobacillus (Lmb.) fermentum, and Ligilactobacillus (Lgb.) salivarius were subsequently identified according to their superior antimicrobial and probiotic-related properties. The selected strains were evaluated for several functional and safety characteristics, including antimicrobial activity, production of lactic acid and hydrogen peroxide (H₂O₂), biofilm formation, auto-aggregation, cell surface hydrophobicity, antibiotic susceptibility, hemolytic activity, and tolerance to acidic conditions. These studies were complemented with comparative genomics using the complete genome sequences of selected strains. Results: The isolates demonstrated significant inhibitory activity against vaginal pathogens associated with aerobic vaginitis, and vulvovaginal candidiasis. In addition, strong correlations were observed between metabolite production and antimicrobial activity. Several strains also exhibited enhanced biofilm formation, aggregation capacity, and favorable safety profiles. Among the tested isolates, Lmb. fermentum 70BJ2, Lpb. plantarum 87JG8, and Lpb.plantarum N17 emerged as particularly promising probiotic candidates due to their combined antimicrobial, metabolic, and adhesion-related properties. Conclusions: Overall, these findings demonstrate that the vaginal microbiota of healthy Algerian women represents a valuable source of potential probiotic strains and provide a strong basis for future in vivo validation and clinical application in the prevention and management of vaginal infections.

The vaginal microbiota contributes to mucosal immune homeostasis, yet the immunomodulatory properties of individual vaginal lactic acid bacteria (LAB) strains remain poorly characterized. In this study, eight LAB strains previously isolated from healthy Algerian women and selected based on their probiotic-related properties were evaluated for their capacity to modulate macrophage immune responses. Seven Lactiplantibacillus plantarum strains (N1, N2, N7, N11, N17, 87JG8, and 87BG2) and one Limosilactobacillus fermentum strain (70BJ2) were initially screened using porcine alveolar macrophages (PAM cells) under basal conditions and following lipopolysaccharide (LPS) challenge. Distinct strain-dependent cytokine profiles were observed. Hierarchical clustering separated the strains into two major groups: N1, N2, N7, and N11 were characterized mainly by stronger inflammatory responses, whereas N17, 87BG2, 87JG8, and 70BJ2 displayed comparatively lower inflammatory responses together with enhanced IL-6 and IL-27 expression at later time points. Based on these profiles, N17, 87JG8, and 70BJ2 were selected for further characterization in porcine intestinal macrophages (IPIM cells) and RAW 264.7 murine macrophages (RAW cells). In IPIM cells, 70BJ2 reduced LPS-induced TNF-α and IL-6 expression, while N17 enhanced IL-10 and IL-27 expression following LPS challenge. In RAW cells, N17 and 87JG8 enhanced several inflammatory and chemokine responses, whereas all three strains increased IFN-γ, IL-12, CSF3, IL-10, and IL-27, with 70BJ2 inducing the strongest IL-10 and IL-27 responses and uniquely increasing CSF2. Overall, vaginal LAB displayed distinct strain- and macrophage-dependent immunomodulatory profiles rather than uniformly suppressing or enhancing LPS-induced inflammation. Among the selected strains, Lmb. fermentum 70BJ2 exhibited particularly prominent regulatory properties across macrophage models. These findings extend the functional characterization of vaginal LAB and support their strain-level evaluation for the identification of candidate immunobiotics capable of modulating mucosal immune responses.