Planta Med 2010; 76(2): 133-136
DOI: 10.1055/s-0029-1186048
Pharmacology
Original Papers
© Georg Thieme Verlag KG Stuttgart · New York

Cytotoxic Effect of the Pentacyclic Oxindole Alkaloid Mitraphylline Isolated from Uncaria tomentosa Bark on Human Ewing's Sarcoma and Breast Cancer Cell Lines

Dolores García Giménez1 , Elena García Prado1 , Teresa Sáenz Rodríguez1 , Angeles Fernández Arche1 , Rocío De la Puerta1
  • 1Department of Pharmacology, Faculty of Pharmacy, University of Seville, Seville, Spain
Further Information

Publication History

received March 3, 2009 revised July 1, 2009

accepted July 13, 2009

Publication Date:
01 September 2009 (online)

Abstract

Preparations from Uncaria tomentosa, a South American Rubiaceae, have been used in the Peruvian traditional medicine for the treatment of infective, inflammatory and tumoral processes. In this study, the pentacyclic oxindole alkaloid mitraphylline was isolated from the dried inner bark of this plant species, and its structure elucidated by analysis of NMR spectroscopic data. Mitraphylline was differentially identified from its stereoisomeric pair isomitraphylline by 15N‐NMR. Its antiproliferative and cytotoxic effects have been tested on human Ewing's sarcoma MHH‐ES‐1 and breast cancer MT-3 cell lines, using cyclophosphamide and vincristine as reference controls. A Coulter counter was used to determine viable cell numbers, followed by the application of the tetrazolium compound MTS [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxy phenyl)-2-(4-sulfophenyl)-2H-tetrazolium] an inner salt. A colorimetric method was employed to evaluate cell viability in this cytotoxic assay. Micromolar concentrations of mitraphylline (5 µM to 40 µM) inhibited the growth of both cell lines in a dose-dependent manner. The IC50 ± SE values were 17.15 ± 0.82 µM for MHH‐ES‐1 and 11.80 ± 1.03 µM for MT-3 for 30 hours, smaller than those obtained for the reference compounds. This action suggests that the pentacyclic oxindole alkaloid mitraphylline might be a new promising agent in the treatment of both human sarcoma and breast cancer.

References

Ph.D. Rocío de la Puerta

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