The influence of surface charge on the antiviral effect of curcumin loaded in nanocarrier system

Background: Curcumin is a well-documented bioactive compound present in Curcuma sp., a tropical, medicinal plant. This substance exhibits broad-spectrum biological activities, includ-ing antivirus. Despite the lack of pharmaceutical properties of curcumin limits its clinical use. Objective: This study aims to produce curcumin nanoemulsion with different surface charge (curcu-min (+) nanoemulsion and curcumin (-) nanoemulsion) and to evaluate its physical characteristics, in vitro cell cytotoxicity, and antiviral activity against dengue virus (DENV) 1 and 2. Methods: Two forms of nanoemulsion were prepared, which were differed from their surface charge through spontaneous procedure resulting in similar characteristics except for the zeta potential value. Cytotoxicity was determined using the RT-PCR method in the A549 cell line, and anti-DENV properties were determined by calculation of inhibitory concentration 50 (IC₅₀) value. Results: The positive charge of curcumin-loaded nanoemulsion showed a better effect in reducing the viral replication represented by a lower IC₅₀ value. In addition, DENV-1 was more sensitive and responsive to curcumin as compared to DENV-2. Conclusion: Positive surface charge of curcumin-loaded nanoemulsion improves the antiviral effect of the curcumin, suggesting a promising approach for alternative treatment for dengue virus in-fection.