Anti-cancer effects and molecular mechanisms of sour tea (Hibiscus sabdariffa) in the human cellular model (A549) of lung cancer

Lung cancer is one of the most common malignancies worldwide that despite the recent progress, its existing treatments have not sufficient efficiency, and scientists are always trying to find complementary therapies. Medicinal plants, such as sour tea, have attracted lots of attention due to their abundant antioxidant compounds. In the present study, in addition to assessing the anticancer effects of sour tea (Hibiscus sabdariffa) on the human cellular model (A549) of lung cancer, the related molecular mechanism of anti-proliferative effects of the extract was investigated through the evaluation of the expression level of Bax and Bcl2 genes.

To this end, after the preparation of the sour tea extract, cellular cytotoxicity was evaluated with an MTT assay. Afterward, the cells were treated again with selective concentrations of the extract, and after 24 h, RNA extraction, cDNA synthesis, and gene expression analysis of apoptosis genes (Bax and Bcl2) were performed with a real-time polymerase chain reaction.

The results of the study showed that sour tea extract reduced the viability of cancer cells in a dose- and time-dependent manner. Furthermore, molecular analysis results revealed that the treatment of cancer cells with sour tea extract could increase the Bax/Bcl2 ratio, which is an important mechanism for triggering apoptosis.

According to the obtained results, sour tea extract had a cytotoxic effect on lung cancer cells, and therefore, could be suggested as a potential complementary therapy for lung cancer after experimental studies and clinical trials.