The effects of Ginkgo biloba extract added to haloperidol on peripheral T cell subsets in drug-free schizophrenia: a double-blind, placebo-controlled trial

Abstract

EGb may improve the decreased peripheral immune functions in schizophrenia. The beneficial effects of EGb on the immune systems and the improvement of schizophrenic symptoms may be medicated through its antioxidant activity.

Oxidative stress in psychiatric disorders: evidence base and therapeutic implications

“…This group also showed superior improvements in peripheral T cell subsets (CD3+, CD4+, CD8+ and IL-2-secreting cells), which were diminished at baseline (Zhang et al, 2006b). These authors additionally reported elevated pre-treatment SOD levels among patients with treatment-resistant schizophrenia, correlating with positive symptomatic severity, which was selectively reduced in patients receiving EGb but not placebo (Zhang et al, 2001a(Zhang et al, , 2006bZhou et al, 1999), thereby suggesting that antioxidant activity, schizophrenia symptoms and peripheral immune functions may be interrelated. A confounder in this group of studies is the use of haloperidol as treatment base, which through its potential in inducing oxidative stress and cognitive blunting, may have added iatrogenic complexities to the disease and treatment process, such that it is difficult to determine whether the superior outcomes were due to lessened adverse effects, underlying psychopathology, or both.…”

“…Furthermore, treatment-emergent behavioural and neurological side-effects were significantly lower in the EGb group (Zhang et al, 2001b). This group also showed superior improvements in peripheral T cell subsets (CD3+, CD4+, CD8+ and IL-2-secreting cells), which were diminished at baseline (Zhang et al, 2006b). These authors additionally reported elevated pre-treatment SOD levels among patients with treatment-resistant schizophrenia, correlating with positive symptomatic severity, which was selectively reduced in patients receiving EGb but not placebo (Zhang et al, 2001a(Zhang et al, , 2006bZhou et al, 1999), thereby suggesting that antioxidant activity, schizophrenia symptoms and peripheral immune functions may be interrelated.…”

Biomarkers in schizophrenia: A focus on blood based diagnostics and theranostics

“…Levels of the chemokine, CCL11, were not only higher in people with Sz but were negatively correlated with performance on the working memory test (r 2 = 0.16) and positively corre lated with a cognitive flexibility task (r 2 = 0.26 [33] ). Moreover, increased S100B positive natural killer cells in blood from people with acute Sz correlated with the perception of stress (r 2 = 0.08 [68] ) whilst increases in CD4 positive cells correlated with an improvement of clinical symptoms in people with Sz (r 2 = 0.1) [63] . In summary, people with Sz demonstrate a distinct profile of immune peptides, aberrant immunological responses, and changes of immune cell counts.…”

“…In lipopolysaccha rides (LPS)-induced or polyinosinic: Polycytidylic acidstimulated PBMC cultures, antipsychotic treatment altered immune function by suppressing the levels of IFNγ and MCP-1 and raising the levels of IL-4, IL-10, IL-18 and RANTES [61,62] . Immune cell counts can also change in people with Sz after antipsychotic drug treatment; haloperidol increased CD3+ T cells, CD4+ T cells, and IL-2-secreting cells, together with CD4/ CD8 ratio after 12-wk of treatment [63] . In addition, clozapine treatment initially (12 wk) increased CD34+ T cells, neutrophils and leukocytes.…”

“…There is evidence to suggest that the levels of some inflammatory molecules in blood are correlated with symptom severity in people with Sz [10,33,48,60,63,67] . For example, plasma levels of IL2 in people with Sz were reported to be positively correlated with the scores in cognitive tests of digit span test (r 2 = 0.17) and intelligence (r 2 = 0.19), and negatively correlated with the presence of negative symptoms (r 2 = 0.2 [67] ), levels of IL1β and TNFα mRNA in PBMC were positively correlated (r 2 = 0.17) with scores on the general psychopathology factor of the PANSS [48] and changes in serum IL-10 levels were significantly correlated with improvements in symptoms [i.e., negative, general psychopathology and total score (r 2 = 0.10.2)] among people with first-onset Sz [60] .…”