Effect of parsley (Petroselinum crispum) extract on memory impairment and anxiety induced by immobilization stress in adult male rats

Background and purpose: Chronic immobilization stress can damage the nervous system, leading to learning and memory disorders, anxiety, and depression.Parsley (Petroselinum crispum) is known for its antioxidant, anti-diabetic, antiinflammatory, and hepatoprotective properties.This study investigates the effects of hydroalcoholic extract of parsley on learning, spatial memory, and anxiety behavior in adult male Wistar rats subjected to chronic immobility stress. Materials and methods:Sixty rats were divided into six groups: control, stress, Parsley 1 (1 mg/kg), Parsley 2 (2 mg/kg), stress-parsley 1, and stress-parsley 2. For 21 consecutive days, rats were restrained for 6 hours daily to induce stress.Hydroalcoholic extracts of parsley were administered via gavage at doses of 1 and 2 mg/kg during this period.Spatial learning and memory were assessed using the Morris water maze, while anxiety behavior was evaluated with the elevated plus maze. Results:In the Morris water maze, stress-parsley groups 1 and 2 showed a significant reduction in the time and distance traveled to reach the hidden platform compared to the stress group (p < 0.01 and p < 0.05, respectively).In the probe test, these groups spent a greater distance and time in the target quadrant compared to the stress group (stress-parsley group 1, p < 0.05; stress-parsley group 2, p < 0.01).Additionally, the elevated plus maze results indicated that the percentage of entries into the open arm and time spent in this arm were significantly higher in the stress-parsley groups compared to the stress group (p < 0.05). Conclusion:In rats exposed to chronic immobility stress, hydroalcoholic Hydroalcoholic extract of parsley improved learning and spatial memory, as well as reduced while reducing anxiety behavior, in rats exposed to chronic immobility stress, suggesting that it might haveits potential therapeutic effects for treating stress-induced disorders.