Improvement of Chemical Stability and Activities of Anthocyanins by Complexation

Chemical stability of anthocyanins in aqueous solutions has been one of the major drawbacks for health applications. Complexation of anthocyanins formed by aqueous extracts of dried cobs of Zea mays L. ceritina Kulesh. (CC) and blue petals of Clitoria ternatea L. (CT) was challenged by thermal accelerated stability testing of total anthocyanins by pH differential method, with in vitro antiinflammatory and anti-candida screening tests. Decomposition of total anthocyanins of the anthocyanin complex (AC), CC and CT in aqueous conditions follows first-order kinetic with derived activation energies of 53.3, 18.0, 34.4 kJ/mol, respectively, indicating higher thermal tolerance by complexation. AC, at concentrations up to 2.5 mg/mL, was not cytotoxic to the exposed human gingival epithelial cells (HGEPp0.5). At 0.1 μg/mL, AC recovers cellular proteins and nucleic acids of TNF-alpha induced inflamed HGEPp0.5 cells, detected by FTIR spectroscopy and principle component analysis (PCA). Anti-candida activity of AC was determined at 80 and 160 μg/mL as the minimum inhibitory and minimum fungicidal concentrations, respectively. It is concluded that complexation improved chemical stability with anti-inflammatory and anti-candida activities of the anthocyanins in an oral epithelial cell line.