Vallaris solanacea induces mitochondrial mediated apoptosis in HL-60 human promyelocytic leukemia cells

In the present study, the apoptosis-inducing potential of a chloroform fraction from an alcoholic extract of Vallaris solanacea aerial parts (VS) was examined using human promyelocytic leukemia HL-60 cells. We discovered a concentration and time-dependent decrease in cell growth using MTT assay. Scanning electron micrographs and fluorescence microscopy were used to observe several well-documented morphological and nuclear alterations, such as reduction in cell size, chromatin condensation, fragmentation, and the creation of cell surface blebs. A considerable rise in the Sub-G₀ population was revealed by cell cycle analysis. Additionally, a dose-dependent rise in cells positive for Annexin V was observed. DCFH-DA test on VS-treated HL-60 cells showed an increase in endogenous ROS generation of up to 4.3 fold. Additionally, suppression in Bcl-2 levels and increased mitochondrial membrane depolarization in treated cells were also associated with a rise in cytosolic cytochrome-c levels that was consequently followed by the activation of the caspase cascade. Further, the DNA fragmentation assay exhibited a typical ladder formation at 25 μg/ml, which became prominent in a concentration-dependent manner. Our study revealed that VS has apoptosis-inducing potential towards HL-60 cells in vitro and is an effective candidate for further anti-cancer studies.