Phenylethanoid glycosides: Naturally occurring apoptosis inducers

Natural products have long been regarded as excellent sources for drug discovery given their structure diversity and wide variety of biological activities. Phenylethanoid glycosides are naturally occurring compounds of plant origin and are structurally characterized with a hydroxyphenylethyl moiety to which a glucopyranose is linked through a glycosidic bound and esterified by a cinnamic acid moiety. There can be one to four sugars in their composition and cinnamic acid esterification generally occurs on a glucose directly bound to phenylethanol moiety [1,2]. To date several hundred compounds of this type have been isolated from medicinal plants and further pharmacological studies in vitro or in vivo have shown that these compounds possess a broad array of biological activities including antibacterial, antioxidant, antitumor, antiviral, anti-inflammatory, neuro-protective, hepatoprotective, immunomodulatory, and enzyme inhibitory actions[1,2].

In this study, we have investigated in vitro anticancer (cytotoxic) activity and structure-activity relationships of 10 different phenylethanoid glycosides against human and murine cancer cell lines, Hep-2 (human epidermoid carcinoma), RD (human rhabdomyosarcoma), and L-20B (transgenic murine L-cells), using MTT method [3,4]. Acteoside, forsythoside B, samioside and teucrioside were exhibited significant cytotoxic activity against tested cancer cell lines in the concentration range of 8–50µg/mL. To determine the selectivity of cytotoxicity, VERO (African green monkey kidney) cell line was used for the comparison and no cytotoxicity was determined. In addition, apoptotic cell death was observed in the histological analysis of tested cancer cell lines.

Keywords: Phenylethanoids, cancer cells, cytotoxicity, structure activity relationship

Acknowledgement: Activity studies were supported by Hacettepe University Research Foundation (Project No: 0302301010).

References: 1. Funes L, et al. (2010) Chemistry and Physics of Lipids 163: 190–199.

2. Korkina LG (2007) Cellular and Molecular Biology 53(1): 15–25.

3.Saracoglu I, et al. (1995) Biological and Pharmaceutical Bulletin 18(10): 1396–1400.

4.Saracoglu I, et al. (1997) Fitoterapia 68(5): 434–438.