Acute and chronic effects of lambda-cyhalothrin-contaminated feed exposure on the liver and testes of adult male rabbits (Oryctolagus cuniculus)

Lambda-cyhalothrin (Lch) is a widely used broad-spectrum pyrethroid insecticide. Here, Lch-contaminated green grass (spray 25 mg/liter water; Cyclone 2.5 EC®) was administered to adult male rabbits for 15 (acute) and 90 (chronic) alternate days. The hepatic serum enzymes alanine aminotransferase and aspartate transaminase were significantly increased in both acute and chronic Lch-exposed rabbits. Histopathologically, the liver of acute Lch-exposed rabbits showed necrotic changes with inflammatory cell infiltration in the periportal areas. Granulomatous inflammation with infiltration of huge inflammatory cells, fibrosis around the inflammation, and bile duct hyperplasia in chronic Lch-exposed rabbits were seen. In addition, cytoplasmic vacuolation of hepatocytes and cholangitis were found.

In testes, the thickness of tunica albuginea was reduced in acute Lch-exposed rabbits and increased with edematous fluid accumulation in the capsular and sub-capsular regions in chronic Lch-exposed rabbits. Spermatogenic cells were degenerated, and their number was decreased significantly (p < 0.05) in the seminiferous tubules of both Lch- exposed rabbits. The Leydig cell population was also reduced significantly (p < 0.05) in both Lch-exposed rabbits. Interestingly, the spermatogenic and Leydig cell populations were significantly reduced in chronic compared to acute Lch-exposed rabbits. The results suggest that Lch has toxicological effects on the liver and testicular tissues, which may cause liver dysfunction and infertility in adult male rabbits.