Evaluation of selected lichens from Iceland for cancer chemopreventive and cytotoxic activity

K. Ingolfsdottir, Kook Lee Sang Kook Lee, K. P.L. Bhat, K. Lee, H. B. Chai, H. Kristinsson, L. L. Song, J. Gills, J. Th Gudmundsdottir, E. Mata-Greenwood, M. S. Jang, J. M. Pezzuto

Research output: Contribution to journalArticlepeer-review

12 Scopus citations


Cancer chemopreventive effects of organic extracts from 29 species of lichens collected in Iceland were evaluated using a panel of in vitro bioassays whereby extracts were tested for potential to induce quinone reductase (QR) and differentiation of human promye-locytic leukemia (HL-60) cells, inhibit cyclooxygenase-1 (COX-1), phorbol ester-induced ornithine decarboxylase (ODC), aromatase and sulfatase, as well as for antioxidant, estrogenic/anti-estrogenic and antiproliferative activity. In addition, the extracts were tested for cytotoxiciry against 12 cancer cell lines. The most significant results were exhibited by extracts from Xanthoria elegans and Alectoria nigricans, which respectively, induced QR activity (concentration to double activity = 4.8 μg/ml) and inhibited phorbol ester-induced ODC activity with mouse 308 cells in culture (1C50 = 2.6 μg/ml). Moderate inhibition of [3H]thymidine incorporation with HL-60 cells was exhibited by the Peltigera leucophlebia extract. Several extracts prevented estrogen formation from estrogen precursors by inhibiting the enzymatic activities of aromatase (Sphaerophorus globosus, Cetrariella delisei, Melanelia hepatizon) and sulfatase (Cladonia gracilis, Sphaerophorus fragilis, S. globosus). None of the extracts demonstrated significant cytotoxic effects with selected cell lines.

Original languageEnglish (US)
Pages (from-to)313-317
Number of pages5
JournalPharmaceutical Biology
Issue number4
StatePublished - 2000
Externally publishedYes


  • Aromatase
  • Cancer chemoprevention
  • Cytotoxicity
  • HL-60 cell differentiation
  • Icelandic plants
  • Lichens
  • Ornithine decarboxylase
  • Quinone reductase
  • Sulfatase

ASJC Scopus subject areas

  • Molecular Medicine
  • Pharmacology
  • Pharmaceutical Science
  • Drug Discovery
  • Complementary and alternative medicine


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