Cinnamon is a natural spice with a wide range of pharmacological functions, including anti-microbial, antioxidant, and anti-tumor activities. The aim of this study is to investigate the effects of cinnamaldehyde-rich cinnamon extract (CRCE) on the colorectal cancer cell lines HCT 116 and HT-29. The gas chromatography mass spectrometry analysis of a lipophilic extract of cinnamon revealed the dominance of trans-cinnamaldehyde. Cells treated with CRCE (10–60 µg/mL) showed significantly decreased cell viability in a time- and dose-dependent manner. We also observed that cell proliferation and migration capacity were inhibited in CRCE-treated cells. In addition, a remarkable increase in the number of sub-G1-phase cells was observed with arrest at the G2 phase by CRCE treatment. CRCE also induced mitochondrial stress, and finally, CRCE treatment resulted in activation of apoptotic proteins Caspase-3, -9, and PARP and decreased levels of mu-2-related death-inducing gene protein expression with BH3-interacting domain death agonist (BID) activation.
Gintonin, a non-saponin glycolipoprotein from Panax ginseng, acts as a lysophosphatidic acid ligand. However, its anticancer effects, especially in melanoma, remain unclear. This study investigated the anti-proliferative effects and intracellular signaling mechanisms of a gintonin-enriched fraction (GEF) from Panax ginseng in human melanoma cell lines. In vitro, GEF treatment significantly inhibited cell proliferation, reduced clonogenic potential, and delayed wound healing in melanoma cells. Flow cytometry and terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) staining showed that GEF induced apoptosis, as evidenced by increased apoptotic cell populations and nuclear changes. GEF also caused cell cycle arrest in the G1 phase for A375 cells and the G2/M phase for A2058 cells. It triggered apoptotic signaling via activation of caspase-3, -9, poly (ADP-ribose) polymerase cleavage, and downregulation of B cell lymphoma-2 (Bcl-2). GEF treatment also raised intracellular reactive oxygen species (ROS) levels and mitochondrial stress, which were mitigated by N-acetyl cysteine (NAC), an ROS inhibitor. In vivo, GEF suppressed tumor growth in A375- and A2058-xenografted mice without toxicity. These findings suggest that GEF from Panax ginseng has potential antitumor effects in melanoma by inducing apoptosis and cell cycle arrest, presenting a promising therapeutic avenue.