Perinatal toxicity of cyfluthrin in mice: developmental and behavioral effects

The present study was undertaken to evaluate the teratogenic and behavioral effects of perinatal exposure to cyfluthrin (Synthetic Pyrethroid) on mice offspring. Humans are exposed to this compound as it is widely used in various household insecticide formulations and in public health programmes. Pregnant females were exposed to 16 mg/kg (low dose) and 32 mg/kg (high dose) body weight cyfluthrin daily by oral intubation from gestation day 14 through parturition and lactation up to weaning. On 18th day of gestation, 50% females were euthanized for teratological studies and the remaining were allowed to deliver their pups normally. The fetuses were weighed and observed for gross external malformations and routine teratological examination was done. The neonates were observed for neuromotor reflexes (surface righting, tail hang reflex and pivoting) from day 1 up to day 7 after birth. Movement and exploratory behavior of weanlings were observed using 'open-field' and 'hole-board.' The fetuses did not show any external malformation. Skeletal aberrations observed included poor ossification of the skull and phalanges and short ribs. Surface righting and pivoting were significantly affected by the high dose. Both doses produced significant changes in the locomotion, exploration, and rearing frequencies in the open-field. The study indicates that cyfluthrin when administered at the above-mentioned doses did not elicit significant teratogenicity but both the doses caused significant difference in behavioral activities.