The influence of mianserin on TNF-α, IL-6 and IL-10 serum levels in rats under chronic mild stress.

BACKGROUND

Antidepressants are known to affect the immunological system through mechanisms which are not completely understood. The aim of the present study was to evaluate the effect of the atypical antidepressant mianserin on the levels of tumor necrosis factor alpha (TNFα), interleukin-6 (IL-6) and interleukin-10 (IL-10) in the blood of rats in an experimental model of depression.

METHODS

Male Wistar rats were subjected to chronic mild stress (CMS) according to Willner's method for 6 weeks. Following the development of anhedonia, the stressed and control rats (non-stressed animals) were treated with mianserin (10 mg/kg ip, twice daily) for three weeks. On the last day of the experiment, a lipopolysaccharide (LPS, 100 μg/kg ip) was injected to mianserin- or vehicle-treated rats. TNFα, IL-6 and IL-10 levels in the blood of the rats were assayed using ELISA methods.

RESULTS

The results indicated a significantly increased TNFα level in stressed animals when compared with the non-stressed (control) group. The levels of IL-6 and IL-10 were also elevated, especially after LPS administration. Treatment with mianserin resulted in a significant lowering of TNFα and IL-6 levels both in LPS-treated and LPS-untreated animals. There was also a decrease in IL-10 concentration in LPS-treated stressed animals.

CONCLUSIONS

The results confirm an increase in proinflammatory cytokines in the blood of rats with experimentally induced depression and show the protective role of the activity of mianserin on the cytokine levels, expressed in a lowering of TNFα and IL-6 levels in stressed animals, and of IL-10 levels after LPS administration.