The Developmental Toxicity of Thymus schimperi Essential Oil in Rat Embryos and Fetuses

Table 9

Skeletal malformations of a 20-day-old rat fetuses following treatment with the essential oil of Thymus schimperi.

Group	Percentage of skeletal malformations
	Sternum^a	Hyoid^b	Ribs^c	Thoracic vertebrae^d	Caudal vertebrae^e
G-I (pair-fed control), n = 50	12	0	0	0	8
G-II (ad libitum), n = 50	14	0	0	0	10
G-III (EO 65 mg/kg), n = 50	16	0	0	0	12
G-IV (EO 130 mg/kg), n = 50	18	0	0	0	14
G-V (EO 260 mg/kg), n = 50	18	0	0	0	16

The percentage of skeletal malformations is calculated (chi-square). ^a<4 ossification centers on the sternum; ^bno ossification signs on the hyoid bone; ^cno ossification signs on the ribs; ^d<13 ossification centers on the thoracic centra; ^e<4 ossification centers on the caudal vertebrae.