In vitro evaluation of anti-proliferative, anti-inflammatory and pro-apoptotic activities of the methanolic extracts of Andrographis nallamalayana Ellis on A375 and B16F10 melanoma cell lines

Natural plant products have been widely used in controlling cancer with fewer or no side effects and the use of plant extracts as complementary to synthetic medicine is gaining increased popularity. Members of Andrographis plants possess important medicinal properties. In the present study, anti-cancerous properties of Andrographis nallamalayana (AN) were tested on A375 and B16F10 skin melanoma cancer cell lines. The leaf extracts of AN significantly reduced the cell viability and cell survival of skin cancer cell lines, achieved by MTT assay and clonogenic assays, respectively. Further, TUNEL assays revealed that AN extracts induces the apoptosis. Western blot analysis revealed that AN leaf extracts reduced the expression of Bcl-2, an anti-apoptotic protein and induced the expression of proapoptotic molecules such as Bcl-2 associated death promoter protein (BAD), Bcl-2 associated X protein (BAX) and cleaved caspase-3. Moreover, the qRT-PCR and western blot analysis demonstrated the reduced expression of G2/M phase proteins cdk1, cyclin B1 and increased expression of p53, cyclin-dependent kinase 1 inhibitor, p21. Further, immunofluorescence analysis revealed that AN reduced the NF-κB nuclear translocation, luciferase reporter assays demonstrated reporter gene activation. qRT-PCR assays showed that AN significantly reduced the expression of NF-κB target genes. The results concluded that the extracts of AN exhibited significant anti-proliferative, anti-inflammatory and pro-apoptotic activities on melanoma skin cancer cell lines.