Acute Toxicity Assessment of Azadirachtin‐Based Pesticides Using Murine Hybridoma and Oyster Cells

Abstract

In vitro acute toxicities of azadirachtin‐containing pesticides (Neemix™ and Bioneem™), formulated with neem tree extracts, and pure azadirachtin (AZA), the believed active ingredient, were studied using hybridoma and oyster cells and were compared to results obtained using the standard in vivo Daphnia pulex toxicity assay. Neem‐based pesticides showed relatively high toxicity to both hybridoma and oyster cells at concentrations of 1 μg AZA/mL and higher. The IC50 values for hybridoma cells were 2.15 μg AZA/mL for Neemix™ and 1.67 μg AZA/mL for Bioneem™. Oyster cells had IC50 values of 2.18 μg AZA/mL for Neemix™ and 9.46 μg AZA/mL for Bioneem™. Purified AZA, however, did not appear to be as toxic as the formulations. D. pulex was also more sensitive to neem‐based pesticide exposure than that of pure AZA. The applications and limits of these two in vitro models for testing the acute toxicity of AZA‐based pesticides are discussed in comparison with the in vivo D. pulex test.