Background: Prenatal valproic acid (VPA) exposure induces disrupted antioxidant defence in offsprings. Several antioxidant substances are being used during the induction period to prevent or decrease this effect. Thymoquinone (TQ), bioactive molecule of black cumin, is reported to modulate oxidative stress by an increase in GSH and SOD and decrease in MDA in experimental disease models. However, consecutive administration of TQ is reported to have negative outcomes due to its hypoglycaemic properties. This study is designed to find the dose of TQ administration with most effective antioxidant activity and least hypoglycaemic effect in VPA induced oxidative stress.

Methods: Pregnant Wistar rats were injected i.p. with 400 mg/kg/ml of VPA on embryonic day 12.5 (E12.5). Repeated dose groups were injected i.p. from E11.5- E14.5; RC- repeated control: didn’t receive TQ, R1: 0,5 mg/kg/ml of TQ, R2: 2 mg/kg/ml of TQ, R3: 4 mg/kg/ml of TQ, R4: 8 mg/kg/ml of TQ. Single dose groups were injected i.p. on E12.5; SC- single control: didn’t receive TQ, S1: 8 mg/kg/ml of TQ, S2: 15 mg/kg/ml of TQ. After injections, food was removed from the cages and blood glucose levels were measured by a drop of blood from the tail veins after 2 hours. Pups were sacrificed on postnatal day 7. GSH, MDA and SOD levels were measured via ELISA method.

Results: Prenatal VPA exposure decreased GSH and SOD levels in RC and SC compared to naïve group. R3 group showed improved GSH and SOD levels compared to RC. There wasn’t any significance for MDA levels between groups.

Conclusion: With suggested route of administration and dose of TQ, a follow up study will be conducted to research further behavioural, morphological and biochemical parameters affected by in utero exposure to VPA.