PT14 Toxicity of Mixtures
Exhibit Hall
8:00 AM - Tuesday
(PT214) Evaluation of Developmental Toxicity of Interaction between Caffeine and Pseudoephedrine using Frog Embryo Teratogenesis Assay-Xenopus (FETAX).
Moser, B1, Daigle, A1, Rayburn, J1, 1 Biology Department, Jacksonville State University, Jacksonville, Al, United States
ABSTRACT- Pseudoephedrine and caffeine are found in many over-the-counter drugs including decongestants and weight loss chemicals. Both are proven central nervous system stimulants, and there has been much discussion about potential interactions of these chemicals on human health. Frog Embryo Teratogenesis Assay-Xenopus (FETAX) was used to determine the developmental toxicity of pseudoephedrine and caffeine mixtures and to determine if synergism or antagonism occurs between the two. FETAX is a 96-hour developmental toxicity assay that screens for direct acting teratogens. Both have both been evaluated for developmental toxicity in FETAX but not as mixtures. Potentiating effects of caffeine on the cardiovascular teratogenicity of ephedrine in chick embryos has been shown. Due to the similarities between pseudoephedrine and ephedrine we wanted to determine if synergism occurred between pseudoephedrine and caffeine. The 96-hr LC50, 96-hr EC50, MCIG, and TI were determined for pseudoephedrine and caffeine in various mixtures. We tested five binary mixtures of the two chemicals. The mixtures were based on the toxic units of each chemical; where one toxic unit was equal to the 96-hr LC50. The toxic unit mixtures tested were pseudoephedrine to caffeine at toxic unit ratios of 0:1, 1:0, 3:1, 1:1, and 1:3. The 0:1 and 1:0 test the individual chemicals by themselves. Toxic units were plotted on an isobole graph to determine if synergism, concentration response or antagonism occurred.
Key words: Caffeine, FETAX, Pseudoephedrine, Mixtures