Sorghum Grain-Derived Kafirin Nanoparticles For Effective Delivery of Corosolic Acid into Breast Cancer Cells for Potential Treatment of Breast Cancer

The protein nanocarrier system provides various benefits, including successfully delivering loaded drugs into cancer cells. The present work successfully developed corosolic acid-encapsulated kafirin nanoparticles (CA-Kaf NPs) to deliver corosolic acid (CA) into MCF-7 cells. The hydrophobic character of CA fails to reach the disease site. Initially, kafirin protein was isolated from sorghum grains and characterized. Then, CA was loaded into kafirin protein using a modified desolvation method, and their physicochemical properties, stability, drug release, and cytotoxic potential were investigated. The efficiency of encapsulating corosolic acid into Kaf NPs was 81.13 ± 1.27% (w/w), and the loading capacity was 8.38 ± 0.51% (w/w). The CA-Kaf NPs exhibited an amorphous nature and spherical shape with a size range of 300-400 nm and a zeta potential of +2 mV. CA-Kaf NPs release CA slowly and steadily in an acidic medium (pH 5.4), and the CA release rate was significantly higher at pH 5.4 (75.17±0.06% (w/w)) compared to pH 7.2 (73.02±0.22% (w/w)). CA-Kaf NPs significantly reduced the viability of MCF-7 cells after 24 h with an IC₅₀ value of 58.08 μg × mL⁻¹ and induced apoptosis. MCF-7 cells treated with CA-Kaf NPs showed standard apoptotic morphological changes, including contracted nuclei and damaged membrane bodies. The release of corosolic acid from CA-Kaf NPs significantly increases reactive oxygen species and damages the integrity of the mitochondrial membrane potential. These findings imply that CA-Kaf NPs, which target the delivery of corosolic acid into MCF-7 cells and facilitate endocytosis, could have a significant therapeutic potential for breast cancer.