Tangeretin’s Anti-apoptotic Signaling Mechanisms in Oral Cancer Cells: In Vitro Anti-cancer Activity

Introduction Citrus fruit peels contain Tangeretin, a natural chemical flavonoid that reinforces plant cell walls and serves as a defense mechanism. Apoptosis, growth inhibition, anti-oxidant, anti-diabetic, and anti-cancer activities are only a few of its many qualities. Tangeretin's principal function is to shield healthy cells or tissues from the harmful effects of chemotherapy. The purpose of this study was to investigate the apoptotic activity of Tangeretin's impact on KB (oral cancer cells) cell lines. Materials and method This study employed Tangeritin, in investigating its effects on oral cancer cells. Oral cancer cells were cultured in Dulbecco's modified Eagle's medium (DMEM), with 10% fetal bovine serum at 37°C in a 5% CO(2) environment. Cell viability was assessed by seeding oral cancer cells in 96-well plates, exposing them to varying Tangeritin concentrations (50 µM, 100 µM, and 200 µM) with growth inhibition of KB cell viability in 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and morphological changes in cells were observed under an inverted light microscope at 10x magnification. The results were reported as mean ± standard error mean (SEM) using one-way analysis of variance through IBM SPSS Statistics for Windows, Version 23 (Released 2015; IBM Corp., Armonk, New York, United States). Result MTT assay showed a significant reduction in KB cell viability when treated with Tangeretin. With a significant decrease in mRNA levels of the anti-apoptotic genes Bcl-2 and Bcl-xL. At 50 µM, 100 µM, and 200 µM, the levels of Bcl-2 were 0.85 ± 0.09, 0.62 ± 0.05, and 0.67 ± 0.05, respectively. Similarly, the mRNA expression of Bcl-xL was 0.82 ± 0.07 for 50 µM, 0.7 ± 0.06 for 100 µM, and 0.77 ± 0.06for 200 µM. The mRNA expression levels of Bax were 1.1 ± 0.09 for 50 µM, 1.4 ± 0.12for 100 µM, and 1.3 ± 0.11 for 200 µM, respectively. Conclusion Tangeretin showed a promising apoptotic activity in KB cells suggesting its utility as an anti-cancer compound. It prevented the growth and proliferation of cancer cells by acting on pro-apoptotic and anti-apoptotic genes. However, this conclusion is mostly based on the in vitro study. Therefore in vivo animal studies were needed to confirm the findings.