The ecotoxicological impact of polystyrene on Lissachatina fulica: a study of growth,  pedal mucus histological changes, and protein mucus analysis

Lissachatina fulica mucin can be used as a nutraceutical agent depending on the quality of their feed. Polystyrene (PS) waste harms soil and plants consumed by snails, potentially affecting the quality of mucin production. This study investigated the impact of PS on growth and mucus-producing cell characteristics as well as the network pharmacology of mucin protein components. Fifty 5–6 cm L. fulica snails (20–24 g) were fed organic waste (OW) and organic waste with PS (OWPS). After 28 days of ad libitum access to food, the snails’ mucus, meat, and shells were collected and weighed. Tissue samples from the anterior and posterior pedal regions were stained with periodic acid-Schiff alican blue (PAS-AB) for histological analysis. L. fulica crude mucin proteins were identified by liquid chromatography-mass spectrometry followed by network pharmacology analysis. PS increased crude fiber, slightly altered snail meat composition, and decreased feed consumption and body weight. The mucus from the OWPS group was more pigmented, viscous, and foamy than that of the OW group. OWPS decreased mucus cell density in the anterior region and reverses dorsal/ventral dominance in the posterior region. A total of 26 active compounds were identified, 19 of which were similar to OW mucin, and 7 were unique to OWPS: Guanine, L-(+)-leucine, 6-amino-5-nitrosouracil, ethyl cyanacetate, D-pantothenic acid, lysine butyrate, and 1-azanylidina-N-cyanosulfonyl methane sulfonamide. Network analysis showed that L-leucine and lysine butyrate (node degree > 10) activate 19 target proteins, thereby enhancing the signals from nerves and the brain that control movement and sensation. PS in snail feed reduced growth and altered mucus properties, potentially due to seven unique active compounds, including L-leucine and lysine butyrate.