The combination of anticancer drugs in nanoparticles has great potential as a promising strategy to maximize efficacies by
eradicating resistant, reduce the dosage of the drug and minimize toxicities on the normal cells. Gemcitabine (GEM), a
nucleoside analogue, and atorvastatin (ATV), a cholesterol lowering agent, have shown anticancer effect with some
limitations. The objective of this in vitro study was to evaluate the antitumor activity of the combination therapy of GEM
and ATVencapsulated in a microemulsion (ME) formulation in the HCT116 colon cancer cells. The cytotoxicity and
efficacy of the formulation were assessed by the 3- (4,5dimethylthiazole-2-yl)-2,5-diphyneltetrazolium bromide (MTT)
assay. The mechanism of cell death was examined by observing the morphological changes of treated cells under light
microscope, identifying apoptosis by using the ApopNexin apoptosis detection kit, and viewing the morphological changes
in the chromatin structure stained with 4′,6-diamidino-2-phenylindole (DAPI) under the inverted fluorescence microscope.
It has been found that reducing the concentration of GEM loaded on ME (GEM-ME) from 5μM to 1.67μM by combining
it with 3.33μM of ATV in a ME formulation (GEM/2ATV-ME) has preserved the strong cytotoxicity of GEM-ME against
HCT116 cells. The current study proved that formulating GEM with ATV in ME has improved the therapeutic potential
of GEM and ATV as anticancer drugs.
