the role of eugenol in the reduction of teratogenic effects of retinoic acid on skeletal morphology of mice embryo

introduction: eugenol (eg), a compound extracted from clove tree, is known for its anti- anaphylactic, anti-inflammation, antiseptic, antibacterial and analgesic properties as well as chain breaking antioxidant in inhibition of lipid peroxidation. retinoic acid (ra), one of the synthetic derivatives of vitamin a, has been frequently used for treatment of face acne. in our studies eg was used to test its probable correcting action on decreasing the toxicity and the teratogenic effects of retinoic acid in female nmri mice embryo. materials and methods: five groups of 8 weeks old pregnant female mice were fed as follows: 1- an oral dose of 60 mg ra per kg b.w. on day 10 of pregnancy, 2- an oral dose of 100 mg/kg b.w. eg for ten days (5th to 15th day of pregnancy), 3- olive oil (solvent) for 15 days, 4-eg plus ra (as in groups 1 and 2) and 5- untreated controls. on day 18 of pregnancy the mice were dissectioned and the embryos were taken from the uterus. the length of the crown rump (cr), cranio-facial (cf), hands, feet and tail were measured and the organs were observed for probable defects. anova , tukeys and chi-square were used for data analysis. results: a positive relationship was observed between the quantity of ra taken by the animals and the frequency of embryonic organ defects. simultaneous administration of eg with ra significantly reduced the frequency and the intensity of embryonic defects. ra could significantly reduce the length of hands, feet, tail, cr and cf (p<0.001). it could also cause embryonic defects such as short lower jaw, spiral tail, foot bending, hand and feet oligodactily and syndactily. simultaneous administration of eg with ra could significantly correct the length reduction in hands, tail and cf by 16, 18.85, 7.44%, respectively (p<0.001), and cr by 6.57% (p<0.05). conclusion: the results of this study show that eg may decrease the teratogenic effects of ra, and might also be suggested as aprotective agent to be used with ra in skin therapy during pregnancy.