Abstract

Piperine is a dietary alkaloid with huge pharmacological importance and was first isolated from pepper extract. It has been reported with anti-cancer, anti-amoebic, anti-mycobacterial, anti-mutagenic, anticonvulsant, anti-asthmatic, immunomodulatory, anti-inflammatory and anti-oxidant activity. Therefore, the current investigation was designed to unveil the anticancer effects of piperine molecule against human breast carcinoma. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay was executed for determination of effects of piperine on breast cancer cell viability. Clonogenic assay was implemented for checking the effect of piperine on clonogenic potency of breast cancer cells. To monitor morphology of cancerous breast cells, phase contrast microscopy was performed after piperine exposure. Apoptosis was checked by acridine orange/ethidium bromine staining assay and by execution of Western blotting analysis. Cell migration and invasion was monitored by transwell chambers assay. Muse flow cytometric analysis was performed for assessing of different cell cycle phases. Western blotting assay was implemented to check the levels of phosphatidylinositol 3-kinase and protein kinase B. Results revealed that piperine induced dose reliant cytotoxicity in MCF-7 human breast cancer cells. Further, application of piperine on cancer cell colonies remarkably reduced the number of cell colonies to minimum. Phase contrast microscopy evidenced some specific morphological modifications indicating apoptosis allied cytotoxicity of piperine like apoptotic bodies, condensed nucleus and membrane blabbing. Acridine orange/ethidium bromine staining assay revealed that piperine induced apoptosis in MCF-7 cells which was further investigated by Western blotting. This revealed increased expression of B-cell lymphoma 2 associated X and reduced expression of B-cell lymphoma 2, indicating apoptosis induction by piperine. Cell migration as well as cell invasive ability of MCF-7 cells was reduced to minimum by the application of piperine in dose dependent-manner. Flow cytometric analysis evidenced that piperine arrested the cell cycle at growth 2/mitosis phase, hence suppressed the breast cancer progression. Finally, Western blotting assay predicted constant expression of phosphatidylinositol 3-kinase and protein kinase B and reduced expression of phosphorylated phosphatidylinositol 3-kinase. Hence, evidenced the blocking of phosphatidylinositol 3-kinase/protein kinase B signaling pathway. In conclusion, the current investigation regarding anticancer effects of piperine against breast cancer revealed remarkable suppression of cancer cells. It induced apoptosis, suppressed cell migration and invasion, blocked cell cycle and phosphatidylinositol 3-kinase/ protein kinase B signaling pathway.