Proapoptotic activities of Oroxylum indicum leave extract in HeLa cells

Objective: To examine the proapoptotic properties of Oroxylum indicum methanol extract on cervical cancer cells. Methods: Methylene blue assay was used to determine the IC50 value of the extract. Western blotting assays were done to analyze the expression of HPV oncoproteins (HPV18 E6 and E7) and apoptotic molecules (caspase-3 and caspase-8). Reverse transcriptase PCR assays were performed to determine genetic alteration of tumor suppressors p53 and pRb and apoptosis markers Fas and FasL. Enzyme-linked immunosorbent assay (ELISA) was done to determine the expression of cytokine levels (IL-6 and IL-12). Results: The determination of IC50 value indicated a higher anti-proliferative activity of the extract compared to cisplatin. After 24 hours of treatment, Western blot analysis showed that treated HeLa cells exhibited a significant down-regulation of HPV18 oncoproteins E6 and E7, and a significant induction of caspase-8 and caspase-3 activation level. Meanwhile, the mRNA expressions of p53, pRb, Fas and FasL were significantly upregulated in treated cells. Moreover, ELISA showed an increased IL-12 and decreased IL-6 production after Oroxylum indicum treatment. Conclusions: The methanol extract of Oroxylum indicum has an anti-proliferative activity and proapoptotic potential. It induces localized-immunity improvements by altering cytokine production in HPV-positive cervical cancer cells.