Antidepressant-Like Effects of Lavandula angustifolia Mill (Lamiaceae) Aqueous and Total Crude Extracts in Wistar Albino Rats

Joseph Okurut,1 Aloysius Magandaazi Lubega,2 Gordon Ewa Odia,2 Godfrey S Bbosa2 1Department of Medical Physiology, Makerere University College of Health Sciences, Kampala, Uganda; 2Department of Pharmacology and Therapeutics, Makerere University College of Health Sciences, Kampala, UgandaCorrespondence: Godfrey S Bbosa, Email [email protected]: Depression continues to be a serious mental health problem among communities in Uganda, with limited access to mental healthcare services. Communities often use medicinal plants, such as L. angustifolia, in the management of depressive disorders with limited information on its effectiveness.Objective: Study assessed antidepressant-like effects of stem-leaf aqueous and total crude extracts of L. angustifolia in depression-like induced behavior in Wistar albino rats.Methods: An experimental laboratory study was conducted on 36 Wistar albino rats (18 males, 18 females). Group I received normal saline, Group II received 10 mg/kg bwt escitalopram, Group III received 200 mg/kg bwt, Group IV received 1000 mg/kg bwt aqueous extract and same doses of total crude extract were used for Group V and Group VI, respectively, using intragastric tube. Depression-like behavior in rats was induced by several manipulations of CUS for 1– 5 weeks. Sucrose preference test (SPT) was used to confirm depressive-like behaviors. Antidepressant-like effects were determined by FST. Durations of immobility, swimming, and struggling were recorded. Data were analyzed using STATA version 13.Results: In the chronic mild stress group, 19.2% preferred sucrose compared to 66.9% in the unstressed group (p< 0.05). L. angustifolia extract (LAE) exhibited antidepressant-like effects in the rats in a completely dose dependent manner at aqueous doses of 200 mg/kg bwt and 1000 mg/kg bwt, respectively. In the FST, dose of 200 mg/kg bwt and 1000 mg/kg bwt of the extract showed a significant reduction in mean immobility time of 1.33± 0.52 min and 1.83± 1.17 min (p< 0.0001) as compared to 1.00± 0.00 min for escitalopram drug and 3.17± 0.41 min of the normal saline control groups.Conclusion: Aqueous extract of L. angustifolia at a dose of 200 and 1000 mg/Kg bwt reduced the duration of immobility and similar findings were observed on struggling and swimming. Findings have provided evidence on the use of L. angustifolia by local communities in the management of depressive-like behaviors in Uganda.Keywords: antidepressant effects, chronic unpredictable stress, sucrose preference test, forced swimming test, lavender, aqueous extract, total crude extract