Endosulfan splenic pathology and amelioration by vitamin C in New Zealand rabbit

Endosulfan, a chlorinated hydrocarbon insecticide/acaricide, is a member of a cyclodiene sub-group of poisons to a wide variety of insects and mites. It is also toxic to humans and animals, but there is limited knowledge about endosulfan-related splenic and overall immunotoxicity. The aim of this study was to review pathological findings of endosulfan toxicity in the spleen and to examine potential protective effects of the anti-oxidant Vitamin C (Vit C). Here, after 6-week exposures, the spleens of New Zealand White rabbits were examined grossly and histopathologically and tissue caspase-3 activity was assessed immunohistochemically. Rabbits in four groups were used: Group END were given by oral gavage a sub-lethal dose of endosulfan (1mg/kg) in corn oil daily for 6 weeks; Group END+C received the same dose of endosulfan daily and Vit C (20mg/kg) every other day by gavage during this period; Group Vit C received oral corn oil daily and 20mg/kg Vit C every other day; and Group OIL received corn oil daily for 6 weeks. Analyses of the tissues collected 1 week after the final dosing revealed lymphocyte depletion and necrosis in spleens of the hosts that received the pesticide (END only and END+C); hemorrhage and slight neutrophilic infiltration was also noted. Caspase-3 immunoreactivity was marked in lymphocytes in all spleens of rabbits in both END groups. Overall, these toxicities were mitigated by Vit C co-treatment; in END+C hosts, markedly decreased depletion of lymphocytes, inflammation and caspase-3 immunoreactivity were observed. However, even with mitigation, the level of toxicity present was still greater than any seen in the spleens of hosts that received OIL or Vit C alone. These results revealed endosulfan could cause toxicity in the rabbit spleen, characterized by depletion of lymphocytes, inflammation, necrosis and hemorrhage, and that this toxicity could begin to be mitigated by Vit C co-treatment.