Prostate cancer (PCa) is the leading cause of cancer related deaths in men. Carica papaya is a popular tropical plant that has been traditionally used for its nutritional and medicinal properties.
We investigated the anti-proliferative responses of papaya leaf juice (LJP) and its various extracts ("biological"- in vitro digested, "physical"- size exclusion, and "chemical"-solvent extraction) on a range of cell lines representing benign hyperplasia, tumorigenic and normal cells of prostate origin.
Time course analysis (by 24h, 48h and 72h) of LJP (1-0.1mg/mL) before and after in vitro digestion, and of molecular weight based fractions of LJP showed anti-proliferative responses. The medium polarity fraction of LJP (0.03-0.003mg/mL) after 72h exposure showed potent growth inhibitory (IC50=0.02-0.07mg/mL) and cytotoxic activities on all prostate cells, with the exception of the normal (RWPE-1 and WPMY-1) cells. Flow cytometry analysis showed S phase cell cycle arrest and apoptosis as a possible mechanism for these activities. Medium polar fraction of LJP also inhibited migration and adhesion of metastatic PC-3 cells.
This is the first report suggesting selective anti-proliferative and anti-metastatic attributes of LJP extract against prostatic diseases, including PCa.
Biomedicine & pharmacotherapy = Biomedecine & pharmacotherapie. 2017 Feb 26 [Epub ahead of print]
Saurabh Pandey, Carina Walpole, Peter J Cabot, Paul N Shaw, Jyotsna Batra, Amitha K Hewavitharana
School of Pharmacy, The University of Queensland, Brisbane, Queensland, Australia; School of Biomedical Sciences, Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Queensland, Australia; Australian Prostate Cancer Research Centre-Qld, Translational Research Institute, Queensland University of Technology, Brisbane, Queensland, Australia., School of Biomedical Sciences, Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Queensland, Australia; Australian Prostate Cancer Research Centre-Qld, Translational Research Institute, Queensland University of Technology, Brisbane, Queensland, Australia., School of Pharmacy, The University of Queensland, Brisbane, Queensland, Australia., School of Pharmacy, The University of Queensland, Brisbane, Queensland, Australia. Electronic address: .