Abstract

Alternaria alternata, an important pathogen of many plants, produces tenuazonic acid (TeA) with bioactivity to microbes, plants and animals. TeA is one of the main mycotoxin to humans and other organisms. Using Chlamydomonas reinhardtii, Vicia faba root tip and three mammalian normal cell lines as target materials, environmental toxicity, genetic toxicity and cytotoxicity of TeA were examined. The growth and chlorophyll concentration of C. reinhardtii were inhibited at above 100 μg/ml concentration, with EC_50(G) of 310.36 μg/ml and EC_50(Chl) of 294.27 μg/ml. The micronuleus test results indicated that MCN‰ was >15‰ only at higher concentrations. TeA inhibited the proliferation and total protein contents of 3T3 mouse fibroblasts (3T3 cells), Chinese hamster lung cells (CHL cells) and human hepatocytes (L-O2 cells) at concentrations ranging from 12.5 - 400 μg/ml. Of the three cell lines, 3T3 cells were the most sensitive to the toxin (EC_50(24h) = 41.64 μg/ml), followed by CHL cells (EC_50(24h) = 59.33 μg/ml), and L-O2 cells (EC_50(24h) = 85.98 μg/ml) had the lowest sensitivity.

Key words: Tenuazonic acid, Chlamydomonas reinhardtii, micronucleus, mammalian cell line, protein content, toxicity.