tenuazonic-acid and Skin-Neoplasms

Anticarcinogenic potential of tenuazonic acid (TA), a mycotoxin isolated from a fungus, Alternaria alternata, on skin tumorigenesis induced by 7,12-dimethyl benz(a) antracene (DMBA) was investigated. Female Swiss albino mice were exposed topically to 100 nmole of DMBA twice weekly for 20 weeks. Another group of animals was treated with 250 microg TA in acetone daily for a period of 1 week, followed by the same dose of TA prior to every application of DMBA. At the end of 14 weeks, all the animals in the group that was exposed to DMBA alone developed tumors, while 40% of the animals in TA-treated group were found to be tumor free. After 20 weeks, there was no further increase in the number of tumor-bearing animals. Results indicated that prior application of TA significantly delayed the onset of tumorigenesis and also reduced the cumulative number of tumors per tumor-bearing animals. The present studies reveal the antitumor and protective potential of TA against polycyclic aromatic hydrocarbon induced skin carcinogenesis.

Topics: 9,10-Dimethyl-1,2-benzanthracene; Administration, Cutaneous; Animals; Anticarcinogenic Agents; Carcinogens; Drug Screening Assays, Antitumor; Female; Mice; Skin Neoplasms; Structure-Activity Relationship; Tenuazonic Acid

Tenuazonic acid (TA) was topically applied to the interscapular region of Swiss albino mice at different doses before the application of 12-O-tetradecanoyl phorbol-13-acetate (TPA). Skin from the painted area was examined for ornithine decarboxylase (ODC) enzyme estimation. It was observed that TA inhibited TPA induced ODC activity. The inhibitory effect of TA was also found in mouse skin tumor promotion in the two stage initiation promotion protocol. There was a remarkable delay in the latency period and decrease in the number of tumors developed and the percentage of tumor bearing animals after TA treatment.

Topics: Administration, Topical; Animals; Body Weight; Enzyme Induction; Female; Mice; Mice, Inbred Strains; Ornithine Decarboxylase; Ornithine Decarboxylase Inhibitors; Skin; Skin Neoplasms; Tenuazonic Acid; Tetradecanoylphorbol Acetate