Development and characterization of curcumin- and 6-gingerol-based nanoemulsion for brain targeting: in vivo, ex vivo and in vitro cell line studies

Abstract Background Today brain tumors are the most life-threatening diseases which universally have a high death rate and reported as a second leading cause of death in not only adults but also children. Several medicinal approaches have been utilized to treat tumors, but the recommended methods had some limitations. Numerous phytoconstituents isolated from various medicinal plants have been reported to have anticancer property, but there are some major reasons for the clinical failure of these compounds such as its poor solubility, bioavailability and tissue distribution and poor absorptivity in the body. Thus, there is a strong need to design the best treatment to cancer cells with great efficiency, less side effects and with promising approach for the delivery strategies. Nanotechnology is proved to be a bridge to overcome the limitation of conventional therapies of drug administration and distribution in the cancer treatment. In the present study, curcumin- and 6-gingerol-based nanoemulsion (CGNE) has been successfully develop and characterized. Result The FTIR spectroscopy of CGNE exhibits typical spectra of both curcumin and 6-gingerol. The pH of CGNE was found to be acidic, and the refractive index value of formulated CGNE was found to be 1.38, indicating the isotropic nature of drugs. Percentage transmittance of nanoemulsion was close to 100%. Zeta potential of optimized nanoemulsion was found to be –29 mV. During ex-vivo drug diffusion studies, 48.4% and 78% diffusion of curcumin and 6-gingerol, respectively, were observed from CGNE at the end of 6 h, and followed the anomalous release mechanism. Conclusion The drug release mechanism of the formulated CGNE was calculated by using the Korsmeyer–Peppas equation, and the diffusion exponent ‘ n ’ for curcumin and 6-gingerol indicated the anomalous release mechanism. In vitro cytotoxicity against the human glioblastoma cell line U373-MG, study demonstrated that the combination of curcumin- and 6-gingerol-based nanoemulsion showed the synergistic result of cell growth inhibition.