Comprehensive Assessment of Lead Bioaccumulation in Helix aspersa (Müller, 1774), Snails: A Study of Histopathological and Biochemical Impacts

Abstract

Background: The snail Helixa spersa is considered a relevant bioindicator of soil pollution by metallic elements due to its resistance and accumulation capabilities. Methods: This study aims to determine the dose-response relationship between different concentrations of lead and its toxic effects on juvenile H. aspersa through a semi-static ecotoxicity test under controlled conditions. In addition, continuous monitoring of carbohydrates, lipids and proteins of the snails affected by this metal was evaluated along with a histopathological study of the hepatopancreas. Result: The two-month lead exposure in H. aspersa resulted in significant alterations in biochemical and histological parameters. Lead concentrations in the hepatopancreas and foot exhibited a dose-dependent increase, with higher levels observed in the former. Elevated lead concentrations (1000 ìg/g and 1500 ìg/g of soil) led to substantial protein increase in both organs, while even lower doses displayed considerable protein elevation in the hepatopancreas. Carbohydrate levels were significantly lower in all contaminated groups compared to controls. Increasing lead concentrations caused a reduction in lipid levels. Histological analysis revealed distinct alterations, including excretory cell hypertrophy, tubule clustering and inflammatory changes in the hepatopancreas of treated snails. Severe histological damage, including inflammatory infiltrates, cellular debris and necrosis, were observed at higher lead concentrations (1000 and 1500 ìg/g). These findings emphasize the impact of lead exposure on biochemical profiles and organ histology in H. aspersa, highlighting the potential ecological implications of heavy metal contamination.