Potent anticancer effects of vitamin C and vitamin C-rich fruit extract (Citrus sinensis L.) on human lung cancer cells

Introduction: Studies have shown that synthetic agents are connected with some complications. This work was designed to study the effects of vitamin C and Citrus sinensis fruit extract (CSFE) on viability, DNA synthesis, and apoptosis stimulation in human lung cancer cells (COR-L105). Methods: The total contents of the phenolics, flavonoids, and ascorbic acid in CSFE were assessed through the Folin-Ciocalteu, aluminum chloride, and dinitrophenyl hydrazine methods, respectively. The cytotoxicity of vitamin C and CSFE on COR-L105 cells was evaluated by the cell viability assay. Measurement of the DNA synthesis was done through the BrdU solution assay. The expression levels of some apoptosis regulatory genes were also evaluated. Results: The total phenolic, flavonoids, and ascorbic acid contents of CSFE were 94.31 ± 2.27 gallic acid equivalents (mg/g) of dry extract, 63.26 ± 2.86 quercetin equivalents (mg/g) of dry extract, and 59 mg/L, respectively. The 50% cytotoxicity concentration (CC50) values of vitamin C and CSFE on cancer cells were 54.6 and 82.7.6 μg/mL, respectively. Vitamin C and CSFE dose-dependently declined the amount of DNA production in the cancer cells. The expression levels of caspase-3 and Bax genes were markedly (P < 0.001) elevated by vitamin C and CSFE, while they reduced the level of Bcl-2 gene (P < 0.05). Conclusion: The findings showed the potent anticancer effects of vitamin C and CSFE against human lung cancer cell lines. DNA synthesis reduction and apoptosis induction can be considered as possible mechanisms of action. However, further surveys are necessary to clarify the accurate mechanism and their efficacy.