Ursolic acid (UA), a pentacyclic triterpenoid found in
various
fruits and herbs, has the potential as an anticancer agent against
multiple cancer types. Nevertheless, its clinical use was limited
by its poor water solubility. To overcome this drawback, several nanocarriers
were proposed to increase the bioavailability and efficacy of UA.
However, the insights into the cellular targets and mechanisms of
UA and UA nanoparticles (NPs) remain limited. In this study, chitosan-coated
poly(lactic-co-glycolic acid) (PLGA/CS) NPs were
loaded with UA. The obtained (UA)-PLGA/CS NPs were spherical with
an approximate size of 250 nm and an encapsulation efficiency of 25%.
Owing to their promising potential as drug carriers, the NPs were
successfully delivered into breast cancer cells (MCF-7 and MDA-MB-231).
Moreover, (UA)-PLGA/CS NPs enhanced the anticancer activity of UA,
as evidenced by the IC50 values of 26.74 and 40.67 μM
in MCF-7 and MDA-MB-231 cells, respectively. These values were lower
than those of free UA (90.25 and 85.63 μM in MCF-7 and MDA-MB-231
cells, respectively). The improved cytotoxicity induced by (UA)-PLGA/CS
NPs can be attributed to apoptosis induction, collective cell migration
and invasion inhibition, and cell proliferation pathway disruption.
These findings led to a better understanding of the anticancer effects
and molecular mechanisms of (UA)-PLGA/CS NPs and their potential targets
for breast cancer therapy.