Toxicity interactions of azole fungicide mixtures on Chlorella pyrenoidosa

by Selleckchem | Apr 23 2023

It is acknowledged that azole fungicides may release into the environment and pose potential toxic risks. The combined toxicity interactions of azole fungicide mixtures, however, are still not fully understood. The combined toxicities and its toxic interactions of 225 binary mixtures and 126 multi-component mixtures on Chlorella pyrenoidosa were performed in this study. The results demonstrated that the negative logarithm 50% effect concentration (pEC50 ) of 10 azole fungicides to Chlorella pyrenoidosa at 96 h ranged from 4.23 (triadimefon) to 7.22 (ketoconazole), while the pEC50 values of the 351 mixtures ranged from 3.91 to 7.44. The high toxicities were found for the mixtures containing epoxiconazole. According to the results of the model deviation ratio (MDR) calculated from the concentration addition (MDRCA ), 243 out of 351 (69.23%) mixtures presented additive effect at the 10% effect, while the 23.08% and 7.69% of mixtures presented synergistic and antagonistic effects, respectively. At the 30% effect, 47.29%, 29.34%, and 23.36% of mixtures presented additive effects, synergism, and antagonism, respectively. At the 50% effect, 44.16%, 34.76%, and 21.08% of mixtures presented additive effects, synergism, and antagonism, respectively. Thus, the toxicity interactions at low concentration (10% effect) were dominated by additive effect (69.23%), whereas 55.84% of mixtures induced synergism and antagonism at high concentration (50% effect). Climbazole and imazalil were the most frequency of components presented in the additive mixtures. Epoxiconazole was the key component induced the synergistic effects, while clotrimazole was the key component in the antagonistic mixtures.

Comments：

The study investigated the combined toxicities and toxic interactions of 225 binary mixtures and 126 multi-component mixtures of 10 azole fungicides on Chlorella pyrenoidosa. The negative logarithm 50% effect concentration (pEC50) values of the 10 azole fungicides ranged from 4.23 to 7.22, with ketoconazole having the highest pEC50 value and triadimefon having the lowest.

The study found that the mixtures containing epoxiconazole showed high toxicity. The model deviation ratio (MDR) calculated from the concentration addition (MDRCA) showed that 69.23% of the mixtures presented an additive effect at the 10% effect level. At higher effect levels, 23.08% and 7.69% of mixtures presented synergistic and antagonistic effects, respectively, at the 10% effect level.

At the 30% effect level, 47.29% of the mixtures presented an additive effect, while 29.34% and 23.36% of mixtures showed synergism and antagonism, respectively. At the 50% effect level, 44.16%, 34.76%, and 21.08% of mixtures presented additive effects, synergism, and antagonism, respectively.

The study also identified the key components that induced synergistic and antagonistic effects. Epoxiconazole was the key component that induced synergistic effects, while clotrimazole was the key component in the antagonistic mixtures. Climbazole and imazalil were the most frequently found components in the additive mixtures.

Overall, the study provides important insights into the combined toxicities and toxic interactions of azole fungicide mixtures on Chlorella pyrenoidosa. The findings suggest that the toxicity interactions at low concentrations are dominated by additive effects, while at high concentrations, both synergistic and antagonistic effects are observed.