Wistar rats randomly assigned to 12 groups received p.o. the control vehicle (distilled water (0.5 ml/kg) or DMSO 0.2%(0.5 ml/kg)) for the first two groups and different doses of CSE1,CSE2, CSE3 or CSE4 (200 and 400 mg/kg) for the 8 following
groups. The eleventh and twelfth groups served as positive controland received p.o. the opioid analgesic morphine (2 mg/kg) or paracetamol (50 mg/kg).