Probiotics can potentially prevent and treat diseases. We examined the inhibitory activity of bacteriocin-like inhibitory substances (BLISs) from potentially probiotic lactobacilli and streptococci on Candida albicans and non-Candida albicans clinical isolates from women with vulvovaginitis. Using agar well diffusion assays, BLISs inhibited both Candida albicans and non-Candida albicans isolates. The BLIS from L. pentosus isolates had the highest anti-Candida activity (33/45; 73.3%), followed by BLISs from isolates of L. paracasei subsp. paracasei (31/45; 68.9%), L. rhamnosus I (30/45; 66.7%), L. delbrueckii subsp. lactis I (30/45; 66.7%), and S. uberis II (30/45; 66.7%). Upon characterization according to the retained activity under variable physical and chemical conditions, the BLISs showed stability against heat, pH, and surfactants, but were protease-sensitive, which suggests a proteinaceous nature of the active substances. Using crystal violet assays, the BLISs reduced the Candida biofilm biomass significantly as compared to a control group that lacked BLISs. In vivo testing of the antagonistic activity was performed using the Galleria mellonella (G. mellonella) larvae model. BLISs significantly improved survival in G. mellonella larvae treated with Candida isolates on the first, second, and seventh days, as compared to larvae inoculated with Candida only (p < 0.01). The results show that BLISs can be used as biotherapeutic agents in vulvovaginal candidiasis.
Nanoparticles of zinc oxide (ZnO NPs), propolis, and the ZnO–propolis composite (ZnO-P NCs) have been synthesized using a biomimetic approach. Zeta potential analysis and Fourier-transform infrared spectroscopy (FT-IR) proved the formation and stability of nanomaterials. Findings using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), EDX-imaging, and transmission electron microscopy (TEM) demonstrated that the particle size of ZnO-P NCs was 9.70 nm. The antioxidant (DPPH radical scavenging) activity of synthesized nanomaterials was investigated. IC50 values of zinc oxide, propolis, and ZnO-P NCs nanoparticles were 2.75, 1.7, and 1.45 mg mL−1, respectively. In addition, their selectivity and anticancer activity for cancer cell lines (Hela and MCF-7) and human normal (W138) cell lines were investigated. ZnO-P NCs were highly effective against the cell line for breast cancer with an IC50 value of 18 µg/mL, indicating its anticancer-promising potent cytotoxicity in breast cancer treatment, and 23 µg/mL against cervical cancer. In addition, the higher observed safety, antioxidant, and anticancer activities for synthesized ZnO-P NCs confirmed the synergistic effect of this combination. It was obtained that the specific mechanisms underlying the synergy effect between zinc oxide nanoparticles and nanopropolis in their composite formulation varied depending on the preparation method, ratio, and concentration of the components.
16 March 2023 in Rendiconti Lincei. Scienze Fisiche e Naturali