Encapsulation of curcumin into layered double hydroxides improve their anticancer and antiparasitic activity

Objectives: Curcumin (CUR) has well-known activity against cancer cells and parasites; however, its applications are limited since this is an unstable molecule, which may suffer degradation by light and temperature, also, the low water solubility reduce its bioavailability. Layered double hydroxides (LDH) are well-known materials owing to the excellent anion exchange capacity, good biocompatibility and low toxicity. Methods: Layered double hydroxides nanoparticles prepared with zinc and magnesium cations were used as a vehicle for CUR in Caco-2, Giardia lamblia and Entamoeba histolytica cultures. The physicochemical properties of Mg-LDH-CUR and Zn-LDH-CUR were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectrometry (FTIR) and X-ray powder diffraction (XRD). Additionally, the load efficiency, release profiles and photostability of CUR were quantified by high-performance liquid chromatography (HPLC) and UV-Vis spectrometry. Then, Mg-LDH-CUR and Zn-LDH-CUR were tested on Caco-2, G. lamblia and E. histolytica cultures. Key findings: The experiments demonstrated that Zn-LDH-CUR protects better against photodegradation by UV light, while Mg-LDH-CUR showed increased toxicity against Caco-2 cell, G. lamblia and E. histolytica, in comparison with free CUR. Conclusions: Layered double hydroxides are good vehicles to improve stability, resistance to degradation of CUR, also they are useful to improve solubility, provide a controlled release and improve the cytotoxic activity. Additionally, it was shown that the composition of the M⁺² cation of LDH affects its properties and structure and that this directly influences its biological activity. The findings are important to select the composition of the encapsulation vehicle for a specific activity.