Use of a new mathematical model in fitting survivorship curves of Drosophila treated with the antioxidant thiazolidine carboxylic acid.

We have recently proposed a mathematical model of survival mortality kinetics. It is based on biological and statistical hypotheses and is able to fit survivorship curves even at advanced ages, where other models fail. The mathematical function contains two parameters, omega and So, related to deterministic and stochastic factors, respectively. In the present paper the model has been applied to a set of survival curves of Drosophila melanogaster. The different curves derived from populations of flies treated with different doses of the antioxidant thiazolidine carboxylic acid (TCA). The treatment induced a significant progressive increase of mean and maximum lifespan up to the TCA dietary concentration of 0.3%. Higher doses of TCA, on the contrary, were toxic, reducing both mean and maximum lifespan. An interpretation of the differential TCA effects has been attempted on the basis of the values assumed by the two model parameters.