Neuroprotective role of Bacopa monnieri extract in modulating depression in an experimental rat model

Abstract

Background: Depression is a common illness with no definite treatment.

Methods: The study involved 2 experimental periods; 45-day (P1) followed by 30-day (P2). 40 adult albino rats were randomly divided into 4 groups. Grp 1 received saline orally while Grp 2 reserpine inraperitoneally (ip) during P1 and P2. Grps 3 and 4 received reserpine during P1, followed by reserpine plus B. monnieri, and reserpine plus citalopram ip during P2, respectively. Forced swimming test (FST) was performed at beginning and end of P1 and P2. Animals were sacrificed by end of P2 and brain taken for histopathological examination and ELISA estimation of serotonin, dopamine, norepinephrine, BDNF, MCP-1, FAS, and Bcl-2.

Results: During P1, reserpine prolonged immobility time (IT) in FST in Grps 2, 3, and 4. IT was subsequently lowered in Grps 3 and 4 but remained elevated in Grp 2 by end of P2. Serotonin, dopamine and norepinephrine were lowered in Grps 2, 3, and 4, but in Grps 3 and 4, levels were comparable to Grp1. BDNF and Bc1-2 were reduced in Grps 2, 3, and 4, with higher levels in Grps 3 and 4 than Grp 2. MCP-1 and FAS were elevated in Grps 2, 3, and 4, but levels were lower in Grps 3 and 4 than in Grp 2. Histopathology showed congested cerebral cortex in Grp 2 and normal cortex in other groups.

Limitations: Only adult male rats were involved and effects of co-administration of B. monnieri and citalopram were not characterized.

Conclusion: B. monnieri improves depression comparable to citalopram in reserpine-induced depression.

Keywords: B-cell lymphoma-2 (Bcl-2); Bacopa monnieri,; Brain derived neurotrophic factor (BDNF); Depression; FAS; Monoamines; Monocyte chemoattractant protein-1 (MCP-1).