Comparative toxicity of abamectin and nano-derived form on land snail, Helix aspersa in attributing to cytotoxicity and biochemical alterations

The comparative toxic effect of Vertimec® 1.8% EC, Fast Max Super® 8.4% SC and nano-derived form of abamectin (ABM) (1% nano-emulsion) as a dermal contact for 48 h against land snail, Helix aspersa was evaluated at laboratorial trail. Acute toxicity values (LD50) were 6.45, 11.97, and 45.95 µg snail-1 for nano-derived form of ABM, Fast Max Super® and Vertimec®, respectively. Nano-derived form exhibited the highest toxic effects (1.86 and 7.12-folds), respect to Fast Max Super® and Vertimec®. Sublethal doses: 1/10 and 1/100 LD50s of the examined compounds were applied to evaluate some biochemical alterations e.g. acetylcholinesterase (AChE), malondialdhyde (MDA), lactate dehydrogenase (LDH), glutathione-S-transferase (GST), acid phosphatase (ACP), alkaline phosphatase (ALP), alanine aminotransferase (ALT), and aspartate aminotransferase (AST), respectively, in haemolymph and digestive glands homogenates. The all treatments significantly decreased AChE activity in ganglia homogenate, respect to control group (untreated). All treatments exhibited MDA level and LDH activity greater than the control in both haemolymph and digestive gland. This concept recognizes the cytotoxic effect of ABM on gastropods. Significant declines in GST, ACP, and ALP activities were exhibited in homogenate of digestive gland for the all treatments.  However, AST/ALT activities exhibited increase greater than untreated group. These findings may explain the role of these doses of ABM for dysfunction in organs of H. aspersa. Thus, prepared nano-emulsion was more potent toxic on land snails. However, H. aspersa is considered a useful tool to assess ecotoxicological impact of pesticides.