Embryotoxic and Teratogenic Effects of Pyriproxyfen on Developing Chick Embryos (Gallus domesticus).

Abstract

Introduction: Insecticides are extensively used in modern agriculture to improve crop productivity; however, their widespread application has raised serious concerns regarding potential health risks to non-target organisms, particularly during sensitive stages such as embryonic development. Pyriproxyfen, a juvenile hormone analog insect growth regulator, is widely employed for controlling agricultural pests and disease vectors due to its high specificity and prolonged residual effectiveness. Despite its broad usage, information.

Objectives: The present study was designed to assess the embryotoxic, teratogenic, and skeletal effects of pyriproxyfen using the chick embryo (Gallus domesticus) as an experimental model.

Methods: Freshly fertilized chick eggs were incubated under standardized conditions and randomly allocated into control, low-dose (0.0025 µg/egg), and high-dose (0.005 µg/egg) groups. Pyriproxyfen was administered into the egg air sac on the 7th day of incubation, whereas control eggs received corn oil alone. Embryos were harvested on the 18th day of incubation and evaluated for mortality, body weight, morphometric measurements, gross morphological abnormalities, and skeletal development using Alizarin Red S staining. Statistical analyses were conducted using Student’s t-test and the Mann–Whitney U test, with significance set at p ≤ 0.05.

Results: Pyriproxyfen exposure produced a significant, dose-dependent increase in embryonic mortality, accompanied by pronounced reductions in body weight and morphometric parameters. Treated embryos displayed a range of teratogenic abnormalities, including limb deformities, beak defects, hematoma, subcutaneous hemorrhage, edema, and sparse body hair. Skeletal evaluation further revealed impaired cranial ossification, vertebral abnormalities, scoliosis, and limb skeletal defects, indicating disruption of normal osteogenic processes.

Conclusions: In ovo exposure to the pyriproxyfen-based insecticide Sumiprempt induced significant embryotoxic and teratogenic effects in chick embryos (Gallus domesticus), characterized by dose-dependent reductions in body weight, altered morphometric parameters, and multiple morphological abnormalities. These findings indicate potential developmental risks of pyriproxyfen formulations to non-target organisms and emphasize the need for careful regulation, controlled use, and further evaluation of chronic and low-dose exposures to support chemical health risk assessment.