Protective effect of aspirin against mitomycin C-induced carcinogenicity, assessed by the test for detection of epithelial tumor clones (warts) in Drosophila melanogaster.

The present study assessed the protective effect of aspirin against carcinogenicity induced by mitomycin C (MMC) by the test for detection of warts/epithelial tumor clones in Drosophila melanogaster. Larvae were treated with different concentrations of aspirin alone (10, 20 or 40 mg/mL) or aspirin in association with MMC. MMC and ultrapure water were employed as the positive and negative control, respectively. Antioxidant activity was determined using the DPPH method. For performing cytotoxicity assay on HeLa cells, the aspirin concentrations used ranged from 200 mmol/L to 3,125 mmol/L. For assessment of apoptosis and necrosis, cells were incubated for 24 h with complete medium in the absence (control group) or presence of aspirin (12.5 mmol/L and 25 mmol/L). The results obtained in the assessment of the possible carcinogenic effects of aspirin at the three concentrations tested indicate no statistically significant increase in tumor frequency compared to the negative control. The anticarcinogenic activity assessment, where the larvae of D. melanogaster were previously induced to tumor formation by MMC and later treated with aspirin, showed a statistically significant reduction in the number of tumors compared to the positive control. Antioxidant activity across the three aspirin concentrations (10, 20 or 40 mg/mL) ranged from 20.81% to 26.5%. It was observed that aspirin reduced growth viability of HeLa cells in a concentration-dependent manner in comparison with the control. These results indicate that aspirin did not induce tumors in Drosophila and reduced MMC-induced carcinogenicity. The antioxidant activity and apoptosis induction appear to be the main mechanisms involved in reducing the frequency of tumors.

Lapachol as an epithelial tumor inhibitor agent in Drosophila melanogaster heterozygote for tumor suppressor gene wts.

The search for new and effective antitumor agents with fewer cytotoxic side effects on normal tissue has increasingly become important. Lapachol, a natural organic compound isolated from the lapacho tree (Tabebuia avellandedae), is chemically identified as belonging to the naphthoquinone group and is known for its anti-inflammatory, analgesic and antibiotic properties, although there are questions about its effectiveness for treating neoplasic cells. We evaluated the antitumoral effects of lapachol by testing for clones of epithelial tumors in Drosophila melanogaster. Seventy-two-hour old larvae bred from wts/TM3, Sb(1) females and mwh/mwh males, were treated with different concentrations of lapachol (20, 40 and 60 µg/mL). Lapachol alone did not significantly increase the number of epithelial tumors. However, lapachol did significantly reduce the number of tumors provoked by doxorubicin.