Acacia catechu Ethanolic Seed Extract Triggers Apoptosis of SCC‑25 Cells

Background: Acacia catechu Willd (Fabaceae), commonly known as catechu, cachou, and black cutch, has been studied for its hepatoprotective, antipyretic, antidiarrheal, hypoglycemic, anti‑inflammatory, immunomodulatory, antinociceptive, antimicrobial, free radical scavenging, and antioxidant activities. Objective: We evaluated the cytotoxic activity of ethanol extract of A. catechu seed (ACS) against SCC‑25 human oral squamous carcinoma cell line. Methods: Cytotoxic effect of ACS extract was determined by 3‑(4,5‑dimethylthiazol‑2‑yl)‑2,5‑diphenyltetrazolium bromide assay, using concentrations of 0.1–1000 µg/mL for 24 h. A. catechu ethanol seed extract was treated SCC‑25 cells with 25 and 50 µg/mL. At the end of treatment period, apoptotic marker gene expressions such as caspase 8, 9, Bcl‑2, Bax, and cytochrome c were evaluated by semiquantitative reverse transcription‑polymerase chain reaction. Morphological changes of ACS treated SCC‑25 cells was evaluated by acridine orange/ethidium bromide (AO/EB) dual staining. Nuclear morphology and DNA fragmentation was evaluated by propidium iodide (PI) staining. Results: A. catechu ethanol seed extract treatment caused cytotoxicity in SCC‑25 cells with an IC50 value of 100 µg/mL. Apoptotic markers caspases 8 and 9, cytochrome c, Bax gene expressions were significantly increased upon ACS extract treatment indicate the apoptosis induction in SCC‑25 cells. This treatment also caused significant downregulation of Bcl‑2 gene expression. Staining with AO/EB and PI shows membrane blebbing, and nuclear membrane distortion further confirms the apoptosis induction by ACS treatment in SCC‑25 cells. Conclusion: The ethanol seed extracts of A. catechu was found to be cytotoxic at lower concentrations and induced apoptosis in human oral squamous carcinoma SCC‑25 cells.