Experimental Therapeutics

British Journal of Cancer (2002) 87, 98–105. doi:10.1038/sj.bjc.6600422 www.bjcancer.com
Published online 25 June 2002

Novel substituted methylenedioxy lignan suppresses proliferation of cancer cells by inhibiting telomerase and activation of c-myc and caspases leading to apoptosis

P Giridharan1, S T Somasundaram1, K Perumal1, R A Vishwakarma2, N P Karthikeyan3, R Velmurugan3 and A Balakrishnan1

  1. 1Centre for Biotechnology, Anna University, Chennai 600 025, India
  2. 2Bio-organic Chemistry Lab, National Institute of Immunology, New Delhi 110 067, India
  3. 3Maruthi Biotech, Chennai 600 034, India

Correspondence: A Balakrishnan, E-mail: arunb@annauniv.edu

Received 15 October 2001; Revised 4 April 2002; Accepted 25 May 2002.

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Abstract

Conventional solvent fractionation and bioactivity based target assays were used to identify a new anti-cancer molecule from Phyllanthus urinaria, a herbal medicinal plant used in South India. At each step of the purification process the different fractions that were isolated were tested for specific anti-proliferative activity by assays measuring the inhibition of [3H]thymidine incorporation, and trypan blue drug exclusion. The ethyl acetate fraction that contained the bioactivity was further purified and resolved by HPLC on a preparative column. The purity of each of the fractions and their bioactivity were checked. Fraction 3 demonstrated a single spot on TLC and showed maximum anti-proliferative activity. This fraction was further purified and the structure was defined as 7'-hydroxy-3',4',5,9,9'-pentamethoxy-3,4-methylene dioxy lignan using NMR and mass spectrometry analysis. The pure compound and the crude ethyl acetate fraction which showed anti-proliferative activities were examined for ability to target specific markers of apoptosis like bcl2, c-myc and caspases and for effects on telomerase. Four specific cancer cell lines HEp2, EL-1 monocytes, HeLa and MCP7 were used in this study. The results indicate that 7'-hydroxy-3',4',5,9,9'-pentamethoxy-3,4-methylene dioxy lignan was capable of inhibiting telomerase activity and also could inhibit bcl2 and activate caspase 3 and caspase 8 whose significance in the induction of apoptosis is well known. We believe that this compound could serve as a valuable chemotherapeutic drug after further evaluations.

Keywords:

in vitro bioscreen, P urinaria, telomerase, tubulin, apoptosis