Cellular Damage after Prolonged Low-dose Exposure of Neonicotinoid in Rats

Abstract Background; Dinotefuran is a new class of neonicotinoids claimed to be harmless to mammals and humans. This claim was daunted by the documented effect of dinotefuran on honeybees and further studies were required. Aim: The study was designed to assess the capaciousness of damage caused by prolonged exposure of dinotefuran in mammals and probable strategy to neutralize its effect. Methodology: Ninety-day trial using Wistar rats (n=45) was conducted while dividing them into three groups: untreated control group, insecticide (dinotefuran) treated group, and dinotefuran treated and vitamin E supplemented group. Dinotefuran was administrated orally (LD 25 ). Vitamin E (alpha-tocopherol) supplementation was given in water ad libitum. Blood sampling was done twice a month, and hematological and biochemical data were recorded. After expiry of trial period, the experimental rats were anesthetized and sacrificed. Organs (kidneys, liver, and heart) were isolated from each groups, weighed, and stored at approximately -20°C till further processing, analysis and histopathology were performed. Results: All the hematological parameters were affected significantly. Histopathology of tissues showed clear necrosis in all the tissues except kidneys. All the biomarkers of oxidative stress and comet assay demonstrated significant cell damage. All the parameters showed improvement after vitamin E supplementation but non-significantly. Significance: These findings were suggestive that even low dose persistent exposure can lead to mutagenicity and carcinogenicity in mammals and other non-target species hence revised policy guidelines and more intelligent use of these chemicals is required.