title: Immunotoxic effects of imidacloprid following 28 days of oral exposure in BALB/c mice.
abstract: Imidacloprid, a neonicotinoid insecticide has been in use worldwide for several years in agriculture and veterinary medicine. It is possible that residue of this compound may be recycled in the food chain and thus information regarding effects from potential exposure to it is warranted. The objective of the present study was to evaluate immunotoxic effects of imidacloprid in female BALB/c mice. Imidacloprid was administered orally daily at 10, 5, or 2.5mg/kg over 28 days. Specific parameters of humoral and cellular immune response including hemagglutinating antibody (HA) titer to sheep red blood cells (SRBC; T-dependent antigen), delayed type hypersensitivity (DTH) response to SRBC, and T-lymphocyte proliferation in response to phytohemagglutinin (PHA) were evaluated. The results showed that imidacloprid at high dose, specifically suppressed cell-mediated immune response as was evident from decreased DTH response and decreased stimulation index of T-lymphocytes to PHA. At this dose, there were also prominent histopathological alterations in spleen and liver. Histopathological analysis of footpad sections of mice revealed dose-related suppression of DTH response. Imidacloprid at low dose of 2.5mg/kg/day did not produce any significant alterations in cellular and humoral immune response and it seemed to be an appropriate dose for assessment of 'no observable adverse effects level' for immunotoxicity in BALB/c mice. The results also indicated that imidacloprid has immunosuppressive effects at doses >5mg/kg, which could potentially be attributed to direct cytotoxic effects of IMD against T cells (particularly TH cells) and that long-term exposure could be detrimental to the immune system.
authors: Department of Veterinary Pharmacology and Toxicology, College of Veterinary Sciences, CCS Haryana Agricultural University, Hisar, India. prarabdh.badgujar@gmail.com
authors: Prarabdh C
authors: PC
authors: Badgujar
authors: S K
authors: SK
authors: Jain
authors: Ajit
authors: A
authors: Singh
authors: J S
authors: JS
authors: Punia
authors: R P
authors: RP
authors: Gupta
authors: Gauri A
authors: GA
authors: Chandratre
mesh_terms: D000284:Administration, Oral; D000818:Animals; D049109:Cell Proliferation / Q000187:drug effects; D004912:Erythrocytes / Q000276:immunology; D005260:Female; D006386:Hemagglutination Tests; D006968:Hypersensitivity, Delayed / Q000473:pathology; D007093:Imidazoles / Q000633:toxicity*; D007306:Insecticides / Q000633:toxicity*; D007668:Kidney / Q000033:anatomy & histology / Q000187:drug effects; D007958:Leukocyte Count; D008099:Liver / Q000187:drug effects / Q000473:pathology; D008168:Lung / Q000033:anatomy & histology / Q000187:drug effects; D008214:Lymphocytes / Q000166:cytology / Q000187:drug effects; D051379:Mice; D008807:Mice, Inbred BALB C; D000073943:Neonicotinoids; D009574:Nitro Compounds / Q000633:toxicity*; D012756:Sheep / Q000276:immunology; D013154:Spleen / Q000166:cytology / Q000187:drug effects / Q000473:pathology; D059551:Toxicity Tests, Subacute
chemical_list: D007093:Imidazoles; D007306:Insecticides; D000073943:Neonicotinoids; D009574:Nitro Compounds; C082359:imidacloprid