Background: Pyrimidine-based drugs stimulate tissue regeneration and immunity,
two components that need to be improved in a number of respiratory diseases of different etiology
(e.g. influenza and asthma). In the present study we investigated relationships between the character
of substitutions in the uracil structure and the impact of the respective uracil derivatives on the
immortalized lung cells.
Methods: The level of cell proliferation, maximum tolerated dose and toxic effect of 5-substituted
uracil derivatives (12 compounds) were studied on the immortalized lung epithelial cells and
compared with the ones of 6-methyluracil.
Results: 5-Carboxyuracil and 1,3-dimethyl-5-carboxyuracil had the lowest cytotoxicity among
the studied compounds. Their maximal tolerated dosage values were 5 times higher whereas the
proliferation index was increased by 25% and 75%, respectively, compared to 6-methyluracil,
known for its positive effects on cell regeneration.
Conclusion: 5-Carboxyuracil and 1,3-dimethyl-5-carboxyuracil have the best perspectives for
further studies on their biological effects.