Design strategy of cuminaldehyde/β-cyclodextrin polymer inclusion complex with superior antibacterial and anti-cancer ability

Cuminaldehyde (CUM) is a bioactive small molecule compound, and it has effects on anti-inflammatory, antioxidant, antitumor and antibacterial effects. However, the hydrophobicity and volatility of CUM lead to a negative effect on both antibacterial and anti-cancer ability. Considering the molecular size of CUM, β-cyclodextrin polymer (β-CDP), which has hydrophilic rim and hydrophobic cavity, is used to encapsulate the CUM by wet grinding method, in order to improve the water solubility and stability of CUM. The host-guest molar ratio of CUM and β-cyclodextrin (β-CD) unit in β-CDP is determined to be 1: 1 and the binding energy is -27.5 kcal/mol by molecular simulation, which indicates that the binding between β-CDP and CUM is not easy to separate under normal conditions. In addition, cuminaldehyde-β-cyclodextrin polymer (CUM-β-CDP) is highly water-soluble, which has an obvious antibacterial ability. Compared the inhibitory effects of CUM and CUM-β-CDP on E. coli and S. aureus, the results illustrate that the minimum inhibitory concentration (MIC) of CUM-β-CDP is 40 mg/ml on E. coli and 5 mg/ml on S. aureus, which is much lower than that of pure CUM. Further, CUM-β-CDP can well inhibit the proliferation and migration of HepG2 cells, exhibits outstanding anti-cancer ability. The successful design of CUM-β-CDP inclusion complex will provide a new method for the delivery of natural drug molecules with low water solubility and it has broad application prospect.