Araucaria heterophylla Resin: Hyalurosomes-based nanocarriers for enhanced antimicrobial, antioxidant and antiviral activity

Abstract

Araucaria heterophylla resin has antibacterial, antifungal, antioxidant, and antiviral activities, however its low solubility and bioavailability limit its therapeutic applications. Hyalurosomes were loaded with Araucaria resin extract to solve these issues. The resin extract's structure was investigated by NMR and FTIR. Resin-loaded hyalurosomes were prepared and analyzed for particle size, zeta potential, and encapsulation efficiency. Well diffusion assays, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) determinations, DPPH radical scavenging assays, cytotoxicity, and antiviral testing against herpes simplex virus type 1 (HSV-1) in Vero cells were used to evaluate the formulations' biological activities. The selected formulation had a stable zeta potential (-24.2 mV), a high EE (97.67 %), and a smaller particle size (57.73 nm). Compared to free resin, the hyalurosomal formulation showed stronger antibacterial action against Klebsiella pneumoniae (MIC: 15.62 µg/mL) and Candida albicans (MBC: 31.25 µg/mL). Encapsulation enhanced the resin's antioxidant activity (IC50: 132.75 µg/mL vs. 757.45 µg/mL for free resin) and led to robust antiviral activity against HSV-1 (IC50: 8.63 µg/mL). Overall, hyalurosomal encapsulation improves Araucaria resin's pharmacological properties by overcoming solubility and bioavailability issues. Hyalurosomes are intriguing nanocarrier systems for developing new therapeutic medicines, warranting additional in vivo and clinical exploration.

Keywords: Araucaria, Heterophylla, Hyalurosomes, Nanocarriers, Antimicrobial Activity, Antiviral Efficacy, Antioxidant Properties