Enhanced Apoptotic Effect of Curcumin Loaded Solid Lipid Nanoparticles

Curcumin is reported to show potent in vitro anticancer effects in a surfeit of human cancer cell lines and majorly in the carcinogenesis of GIT, in animals. Its poor pharmacokinetics and stability limit its vivo clinical efficacy for the other systemic cancers. We recently reported on a 32-155 times enhancement in bioavailability of curcumin when incorporated into solid lipid nanoparticles (C-SLNs). Presently we report on a 54-85% reduction in IC50 values with developed C-SLNs in comparison to free curcumin against a panel of human cancer cell lines (HL-60, A549, and PC3). Results demonstrate mechanisms similar to those claimed for free curcumin, including induction of cellular apoptosis by activation of caspases, release of cyctochrome c, loss of membrane potential, blockade of nuclear factor kappa B (NF-kappa B) activation, and upregulation of TNF-R for C-SLNs. However, the extent of cell death provided by C-SLNs in all these tests was significantly higher (p < 0.001). This may be attributed to the presentation of curcumin in a dispersible/soluble form which enhanced permeability across the cell surface. The display of significantly better in vitro anticancer effect coupled with high in vivo bioavailability points toward a great potential of using C-SLNs for cancer therapeutics.