Smokeless tobacco ‘ sadagura’ and areca nut extract exposure induces extensive embryotoxicity in chick embryo, Gallus gallus domesticus

Areca nut (AN) and sadagura (SG, homemade smokeless tobacco) are often consumed alone or in combination irrespective of gender including pregnant women in the southern region of Assam, India. However, very few studies have been carried out so far to evaluate its ill effect during embryogenesis. The present study aims to determine the effects of AN, SG, and combination of both (AN + SG) in developing chick embryos as it serves as an excellent model for teratogenic and developmental toxicity study owing to its similarity with the human embryo. Fertile White Leghorn chicken eggs (Gallus gallus domestucus) were exposed to different concentrations of 0.125, 0.25, 0.5, and 1 mg/egg of AN, SG, and AN + SG extract, respectively. The eggs were divided into four groups: control, AN extract-, SG extract-, and AN + SG-treated group. Three different parameters, viz. mortality rate, morphometric measurements, and qualitative anomalies, were studied to observe teratogenic effects. Results indicated a dose-dependent increase in mortality rate in all the treatment groups. Also, quantitative measures suggested significant decrease (p < 0.001) in wet body weight, crown–rump length, anterior–posterior head length, and eyeball diameter in all the concentration of AN, SG and AN + SG of treatment groups when compared to control group. Compared to control, anomalies like microcephaly, microphthalmia, deformed beak, hemorrhage, omphalocele, flexed limbs, and ectopia cordis were prominent in treated groups. Our findings depict organ-specific as well as systemic defects in the developing embryos. Our results suggest that exposure to AN, SG, and AN + SG causes adverse developmental abnormalities and embryo mortality in the chick embryo.