Antitumor activity of psoralen on mucoepidermoid carcinoma cell line MEC-1

Psoralen (PSO) was found cytotoxic against in vitro cultured human mucoepidermoid carcinoma cells of MEC-1 cell line. Its IC50 value was 8.6 micrograms/ml, and relative antitumor activity (RAA) 15. PSO suppressed DNA synthesis, damaged microvilli and cell membrane, and induced degeneration of mitochondria. It inhibited the growth of MEC-1 cells transplanted in nude mice by 79.1% which was as strong as pingyanmycin (PYM 81.4%). The body weight loss of PSO treated tumor-bearing mice was 5%, whereas that of PYM treated ones 13.3% (P < 0.01). PSO may be an effective agent for the treatment of human mucoepidermoid carcinoma.