Water dispersible α-mangostin by self-assembly process

Abstract

α-Mangostin, major bioactive compounds in Garcinia mangostana Linn, displays various interesting biological activities. However, the poor water solubility of α-mangostin has limited its use in the cosmetics and pharmaceutics. Here, we solve α-mangostin's solubility by creating water dispersible α-mangostin particles through self-assembly process with no need of any auxiliary agents such as polymers or surfactants. The simple and upscalable process gives 100% pure α-mangostin spherical particles with nanometer sizes. FT-IR result suggests that intermolecular interaction among α-mangostin molecules in the nanoparticles is weaker than that of the original α-mangostin solid. The lower thermal stability of the particles as compared to that of the original α-mangostin agree with the FT-IR result. The XPS results of α-mangostin particles show more accumulation of hydrophilic functional groups at the surface than that observed at the surface of the original α-mangostin. Nevertheless, the obtained water dispersible α-mangostin particles show the same chemical structure as the original α-mangostin. 3,6-Dibutoxy-α-mangostin prepared through the SN2 substitution reaction, could not form water dispersible particles using similar preparation process. This helps strengthening our hypothesis that the hydroxyl group of α-mangostin molecules is essential for the water-dispersibility character of the self-assembled particles. The water dispersible α-mangostin particles show a similar anti-acne activity to that of the original α-mangostin. At 12.7 ppm (non-cytotoxic concentration), the anti-inflammatory activity of α-mangostin nanoparticles is 5 times higher than that of the original α-mangostin.