In silico and in vitro evaluation of apoptotic induction potential of andrographolide in breast carcinoma cells

Andrographolide (AGL) is a labdane diterpenoid that has been isolated from the stem and leaves of Andrographis paniculata. In Ayurvedic tradition, Andrographis, commonly known as Kalmegh or “King of Bitters” has long been used as a bitter tonic, to promote digestion and appetite. Recently, there are many reports that have findings on anti-inflammatory and cytotoxic activites of AGL. This motivated us to carry out this study, in which we aimed at investigating the anti-apoptotic potential of AGL with special emphasis on breast cancer. One of the major anti-apoptotic proteins that are found to be over-expressed in cancers is Bcl-2 (B-cell lymphoma 2). We performed molecular docking analysis of AGL against Bcl-2 followed by prediction of ADME/Tox analysis. The docking results showed that AGL interacts potentially with BcL-2 with a docking score of -4.675 Kcal/mol. It also has significant pharmacokinetics property evaluated using preADMET tools. Following that the docking results have been evaluated in MCF-7 cell line. The cytotoxicity of AGL has been analysed using MTT assay. It was found that at a minimal concentration of 80µM, AGL was toxic to MCF-7 cells. To confirm the apoptotic induction in cells after AGL treatment, Ao/EtBr dual staining was performed. It was found that about 54% of cells were showing apoptotic induction. Further to support the same, DNA fragmentation analysis was performed in Agarose gel electrophoresis and it was found that intact genomic DNA was visualised in case of untreated cells whereas in AGL treated cells, fragments of DNA were visualised. Thus, the study provides clear indication that AGL possibly has an anti-cancer activity by inducing apoptosis in cancer cells.