Valerenic acid and Valeriana officinalis extracts delay onset of Pentylenetetrazole (PTZ)-Induced seizures in adult Danio rerio (Zebrafish)

Table 1 Progression toward clonic-like movement with PTZ in adult zebrafish

Stage	Stage description	PTZ Concentration at which the behavior is first seen
1	Stay or move near the bottom of the tank	0.10 mg/ml (0.72 mM)
2	Rapid movement in all directions,	0.10 mg/ml (0.72 mM)
3	Hit the tank walls	0.50 mg/ml (3.6 mM)
4	Rapidly go to the water surface and then rapidly go to the bottom of the tank	0.70 mg/ml (5.0 mM)
5	Shaking movement	^a
6	Erratic movements (circular motion, diagonal movement)	0.70 mg/ml (5.0 mM)
7	Wild jumping, Clonic-like movement (convulsion) then loss of coordination/ posture, remaining at the bottom	0.70 mg/ml (5.0 mM)
8	Recover posture/motion	0.70 mg/ml (5.0 mM)
9	Death	1 mg/ml^b (7.5 mM)

Zebrafish (n = 6–12 per concentration) were exposed to different concentrations of pentylenetetrazole (PTZ) for 30 min. The development of convulsions was analyzed by observation of video tapes. At higher concentrations (6–20 mg/ml) some pre-convulsion stages were not observed
^aFew naive zebrafish presented this stage, but it was observed in zebrafish challenged with PTZ (3 mg/ml, 21.7 mM) after pretreatment with AEDs or valerians
^bSome animals survived after 30 min