Andrographolide-Loaded Nanoemulsion and its Activity against Non-Melanoma Skin Cancer Cells

Abstract

Andrographolide (AG) is a diterpenoid lactone found in Andrographis paniculata leaves and stems. It has excellent activity against various cancer cells, for example, skin cancer cells. However, application of AG for skin cancer treatment in clinical trials is limited due to its poor water solubility. To overcome this problem, oil in water AG-loaded nanoemulsion (AG-NE) would be prepared. The objectives of this study were to investigate physicochemical properties of AG-NE and to determine its activity against non-melanoma skin cancer cells. Nanoemulsion (NE) without AG (NE base) and NE containing AG (0.1%w/w) were prepared by high-pressure homogenization technique. They contained a mixture of Tween 80 and Span 80 (5:1) (10% w/w) as an emulsifier. Their droplet size, zeta potential and physical stability were evaluated. Cytotoxicity of AG and AG-NE to non-melanoma skin cancer cells (A-431 cells) and normal skin fibroblast cells (HFF-1 cells) were investigated. The results showed that NE base and AG-NE had droplet size in a nanometer range. They had low viscosity with the flow behavior consistent with Newtonian liquids. Although their zeta potential values were slightly low, they showed good physical stability against centrifugal force. AG and AG-NE were not toxic to HFF-1 cells, but they could induce apoptosis of A-431 cells with IC50 of 25.83 μg/ml and 58.32 mg/ml, respectively. Therefore, AG-NE has become possible to use for investigation of its efficacy and safety in animal models and clinical trials.