Effect of Angelica Sinensis extract on depression behaviors and brain inflammatory factors in depression model rats induced by chronic unpredictable mild stress

Abstract

Objective To observe the effects of Radix Angelica Sinensis (RAS) on depression behavior and cytokines, TNF-α and IL-6, in the hippocampus and prefrontal cortex of depression model rats induced by chronic unpredictable mild stress (CUMS). Methods 32 adult male rats weighting 140-160 g were randomly divided into 4 groups: Control, CUMS, CUMS+ fluoxetine and CUMS+ RAS groups.CUMS procedure went on 5 consecutive weeks and during the last 3 weeks the rats in CUMS+ fluoxetine and CUMS+ RAS groups were taken RAS or fluoxetine via intragastric administration. After 5-week CUMS procedure, rats were subjected to sucrose preference test, forced swimming test and open field test. After behavioral tests were finished, all rats were anesthetized with 10% chloral hydrate (350 mg/kg, intraperitoneal injection) and then decapitated. The hippocampus and prefrontal cortex of rats were separated and ELISA was used to detect the expression of TNF-α and IL-6 in these regions. Results Comparing with control rats, rats exposed to CUMS showed decreased sucrose preference ratio((42±15)%), prolonged immobility time ((68.28±16.50)s), decreased crossing numbers (31.25±21.56) and increased TNF-α ((206.14±30.53)pg/ml) and IL-6 ((369.51±103.81)pg/ml) expression in hippocampus and TNF-α((199.33±25.67)pg/ml) and IL-6 ((347.74±81.04) pg/ml) expression in prefrontal cortex (P<0.01). However, RAS treated rats reversed the behavioral changes such as sucrose preference ratio((66±21)%), immobility time ((32.53±10.26)s) and crossing numbers (83.00±23.25), meanwhile reduced TNF-α ((53.42±12.43)pg/ml) and IL-6((93.84±13.19)pg/ml) expression in hippocampus, TNF-α((57.58±8.33)pg/ml) and IL-6((91.18±17.37)pg/ml) expression in prefrontal cortex among stress rats (P<0.01). Conclusion RAS can ameliorate CUMS induced depression behaviors of rats through regulating hippocampus and prefrontal cortex cytokines (TNF-α, IL-6). Key words: Radix Angelica Sinensis; Depression; Chronic Unpredictable Mild Stress; TNF-α; IL-6