Chara vulgaris-mediated selenium nanoparticles: a novel approach to antioxidant, antibacterial, anti-inflammatory, and wound healing activities

Background Chara vulgaris ( C. vulgaris ), a green macroalga containing antioxidant and antibacterial compounds, shows potential in treating infections and inflammation. Enterococcus faecalis is an opportunistic Gram-positive pathogen responsible for skin and soft tissue infections, especially in compromised patients. Due to rising antibiotic resistance, new treatments are needed. Selenium nanoparticles (SeNPs) have enhanced antimicrobial and antioxidant properties. This study explores C. vulgaris -derived selenium nanoparticles (CV-SeNPs) as a therapeutic agent against E. faecalis infection, aiming to inhibit biofilms, reduce oxidative stress, decrease inflammation, and promote wound healing. Methods Phenolic and flavonoid compounds estimation in the C. vulgaris ethanolic extract was conducted by HPLC analysis. Antioxidant activity was assessed with DPPH and ABTS radical scavenging assays. Broth dilution and crystal violet microtiter plate tests measured antibacterial and antibiofilm effects, respectively. Confocal laser scanning microscopy (CLSM) was used to observe CV-SeNPs’ effects on bacterial biofilm structure. An in vitro wound-healing test evaluated CV-SeNPs’ regenerative potential using normal fibroblasts. Additionally, levels of TNF-α and IL-1β were measured with ELISA kits. Results HPLC of C. vulgaris ethanolic extract consists of many compounds with antioxidant, antibacterial, and anti-inflammatory activities. In DPPH and ABTS assays, CV-SeNPs showed notable antioxidant activity compared to C. vulgaris extract and free SeNPs. The MIC of CV-SeNPs against E. faecalis ( n = 10) ranged from 128-1024 µg/ml in 70% of the tested isolates. CV-SeNPs significantly reduced bacterial biofilm formation, with the percentage of reduction of biofilm equaling 58.3% when compared to untreated cells, confirmed by CLSM observations. In vitro wound healing tests demonstrated that CV-SeNPs accelerated healing, with the fastest rate observed after 48 hours through cell migration into a created wound. Additionally, CV-SeNPs significantly lowered levels of TNF-α and IL-1β, indicating potential anti-inflammatory effects. Conclusions The unique properties of CV-SeNPs suggest this compound could be an effective antioxidant, antibacterial, and anti-inflammatory agent.