PX-12 intervention in the rat model of 4NQO-induced oral carcinogenesis

Another 22 male SD rats (4 weeks of age and 75–100 g in weight) were divided into 2 groups. In the experimental group (n=16), the rats were fed daily with 20 ppm 4NQO (Sigma-Aldrich; Merck KGaA) solution in their drinking water for 24 weeks. The rats in the normal control group (n=6) were fed with distilled water only. At week 18, the experimental rats were divided into 2 groups as visible lesions of tongue dysplasia had appeared. One group was injected with PX-12 (12 mg/kg) weekly via the tail vein. The other group and the normal control group were injected with an equal amount of saline. The rats were sacrificed at week 24. The tongues were dissected, and a longitudinal mid-lingual incision was made. The specimens were collected and analyzed as described below.