Apoptosis is an important process of cell death that controls the intrinsic and extrinsic pathways.
Syringic acid (SRA)-a phenolic compound well-known in traditional Indian
Ayurvedic medicine-has been reported to suppress cell proliferation of various
cancer cells. Therefore, the current study aimed to investigate the inhibitory role of SRA on the proliferation of
oral squamous cell carcinoma cells (SCC131) via
reactive oxygen species (ROS) and induced mitochondria-mediated apoptosis. The study results showed that SRA (IC50 ) was able to induce apoptosis in SCC131 cells via increased ROS generation, alteration of mitochondrial membrane potential, nuclear fragmentation, apoptotic morphological differences, and DNA injury. Moreover, SRA inhibited proliferative markers such as
proliferating cell nuclear antigen and
cyclin D1 protein expression in SCC131 cells. A diminished level of
B-cell lymphoma 2 (Bcl-2) and augmented level of
Bcl-2-associated X protein (Bax) were considered as markers of apoptotic cell death. In addition, SRA was able to decrease Bcl-2 and increase mutant p53,
caspase-9, Bax, and
caspase-3 expression in SCC131 cells. Taken together, SRA succeeded in inhibiting SCC131 cell growth through the ROS and mitochondria-mediated apoptosis in
oral cancer cells.