Intricatinol synergistically enhances the anticancerous activity of cisplatin in human A549 cells via p38 MAPK/p53 signalling

Platinum containing drugs are widely used to treat advanced lung carcinomas. However, their clinical success is still limited due to severe side effects, and drug resistance. Alternative approaches are warranted to augment efficacy of platinum based chemotherapeutic drugs with minimal side effects. Intricatinol (INT), a homoisoflavonoid, has been shown to possess anti-tubercular, antioxidant, hypoglycaemic, and hypolipidemic activity. However, its anticancer activity largely remains unknown. In the present study, we have evaluated anticancer potential of INT alone or in combination with cisplatin (CIS) in non-small cell lung carcinoma (A549) cells. Treatment with INT alone reduced the viability of A549 cells in a dose-dependent manner. Interestingly, the combination of low doses of INT and CIS exerted a synergistic effect and induced apoptosis as evident by DNA fragmentation and Annexin V positive cells. Enhanced Bax:Bcl-2 ratio, loss of Delta psi m, cytochrome c release, cleavage of caspase 3 and PARP1 strongly corroborated our findings. Further, increased expression of p53, p38 MAPK and their phosphorylated counterparts, loss of clonogenicity and reduced migration potential were also recorded with INT + CIS treatment. Most interestingly, INT could not induce any significant cell death in primary mouse embryonic fibroblasts (MEFs). Moreover, no additive or synergistic effect was noted with INT + CIS in MEFs under similar treatment conditions. In conclusion, INT has a selective anticancer potential and could synergize cytotoxicity of CIS. Therefore, the combination of INT and CIS may serve as an effective anticancer strategy for the treatment of non-small cell lung carcinoma.