There are accumulating reports regarding poor response to the common
antidepressant therapy. Antidepressant resistance has often been
associated with activation of the inflammatory system. Accordingly,
major depressive disorder (MDD) patients displaying inflammation prior
to the treatment are less responsive to antidepressants. We hypothesized
that the inefficacy of antidepressant therapy in some patients could be
due to the drugs’ inflammatory mode of action that remained overshadowed
by their substantial therapeutic value. Bupropion is a common-used
antidepressant that is prescribed for seasonal affective disorders and
smoking cessation as well. Nevertheless, there are some reports
regarding inflammation induction and depressive behavior exacerbation in
response to bupropion. Here, we put a spot on bupropion and investigate
the alterations of innate and adaptive immunity cytokines and the
influence on immune signaling pathways. Therefore, we treated
LPS-stimulated human peripheral mononuclear cells (PBMCs) with different
doses of bupropion. Pro-/ anti-inflammatory cytokines (TNF-ɑ, IL-1ß,
IL-17, and IL-10) on both transcriptional and translational levels are
assessed as well as the involvement of the JAK2 /STAT3, TLR2, and TLR4
signaling in this process. Bupropion decreased IL-17A, TNF-ɑ, and IL-1ß
protein levels in the cultures. Nonetheless, the results regarding the
target genes expression were controversial. Surprisingly, IL-1ß, TNF-ɑ,
and IL-17A genes expression increased following bupropion treatment.
TLR2, TLR4, JAK2, and STAT3 gene expression also rose in response to
bupropion. Our findings suggest that bupropion possesses
pro-inflammatory properties especially at concentrations of 50 and 100
and would rather be co-administrated with anti-inflammatory agents at
least in patients with inflammatory conditions.