ANTIPROLIFERATIVE EFFECT OF BROMELAIN LIKE CYSTEINE PROTEASE (PSA/BP-07) FROM Billbergia pyramidalis (Sims) Lindl. ON HUMAN MALIGNANT CELL LINES - A PRELIMINARY STUDY

Abstract

  Billbergia pyramidalis (Bromeliaceae) a genus originated at south Brazil is a tropical and tender perennial. In the present study investigations have been carried out on proteolytic activities of purified protease from B.pyramidalis, using gelatin as substrate. The proteolytic activity of the purified enzyme was inhibited by thiol blocking agents particularly iodoacetamide and mercuric chloride, signifying that the enzyme belongs to the cysteine protease family. The similar results with Bromelain a cysteine protease from Ananas comosus (pineapple) of Bromeliaceae family was also observed. Bromelain is a proteolytic enzyme and has been scientiï¬cally identiï¬ed as a therapeutic agent. The objective of this study was to investigate the activity of a protease identified as cysteine protease (PSA/BP-07), from the leaves of B.pyramidalis, in terms of antiproliferation against four different human malignant cell lines namely Human skin carcinoma cell line (A431),Human breast adenocarcinoma cell line (MCF-7), Human cervical cancer cell line (HeLa), Glioma cell line Hs 683, and a non-cancerous 3T3- L1 Preadipocyte (HeLa) cell line from mouse, using MTT assay in vitro. The protease was found to exhibit potent antiproliferative activity on A431 cell line with an IC₅₀ value of 80.72 µg/ml but trivial inhibitory effect on 3T3- L1 cell line with an IC₅₀ value of 172.06 µg/ml. In conclusion, our findings indicate that the plant cysteine protease obtained from B. pyramidalis could further be explored as a novel source of cancer therapy.