Altered Antioxidant Defenses in Drug-Naive First Episode Patients with Schizophrenia Are Associated with Poor Treatment Response to Risperidone: 12-Week Results from a Prospective Longitudinal Study.

Abnormal redox regulation is thought to contribute to schizophrenia (SCZ). Accumulating studies have shown that the plasma antioxidant enzyme activity is closely associated with the course and outcome in antipsychotics-naïve first-episode (ANFE) patients with SCZ. The main purpose of this study was to investigate the effect of risperidone on oxidative stress markers in ANFE patients and the relationship between risperidone response and changes in oxidative stress markers. Plasma activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) enzyme, total antioxidant status (TAS), and malondialdehyde (MDA) levels were measured in 354 ANFE patients and 152 healthy controls. The clinical symptoms were evaluated by the Positive and Negative Syndrome Scale (PANSS). Patients received risperidone monotherapy for 12 weeks and oxidative stress markers and PANSS were measured at baseline and at follow-up. Compared with healthy controls, the patients exhibited higher activities of SOD, CAT, and TAS levels, but lower MDA levels and GPx activity. A comparison between 168 responders and 50 non-responders at baseline and 12-week follow-up showed that GPx activity decreased in both groups after treatment. Moreover, GPx activity decreased less in responders and was higher in responders than in non-responders at follow-up. These results demonstrate that the redox regulatory system and antioxidant defense enzymes may have predictive value for the response of ANFE patients to risperidone treatment.

More dampened monocytic Toll-like receptor 4 response to lipopolysaccharide and its association with cognitive function in Chinese Han first-episode patients with schizophrenia.

OBJECTIVE: Accumulating evidence suggests alterations of the innate immune system are related to schizophrenia, although the precise mechanism remains to be elucidated. In this study, we aimed to detect the monocytic toll-like receptor 4 (TLR4) expression under basal and lipopolysaccharide (LPS)-stimulated conditions in first-episode (FE) Han Chinese patients with schizophrenia, as well as its association with cognitive function. METHODS: Whole blood samples were taken in 42 FE schizophrenia patients and 36 healthy controls. Expressions of TLR4 on monocytes under basal and LPS-stimulated conditions were measured with flow cytometry. Psychopathological symptoms of schizophrenia were assessed by the Positive and Negative Syndrome Scale (PANSS) and the MATRICS Consensus Cognitive Battery (MCCB) was administered to all of the participants. RESULTS: We found no differences in percentage and mean fluorescence intensity (MFI) of TLR4 expression on monocytes between patients and controls at basal status. However, LPS challenge resulted in a lower cell-surface level of TLR4 on monocytes in FE schizophrenia patients as compared to healthy controls (TLR4+%: F = 4.092, p = 0.047; TLR4 + MFI: F = 4.820, p = 0.031). In addition, correlation analysis together with multivariate linear regression analysis identified basal percentage of TLR4 in monocytes as the beneficial factor for visual learning and working memory in FE patients with schizophrenia. CONCLUSIONS: Our findings suggested that TLR4 may be involved in the pathophysiology of schizophrenia, corroborating the role of innate immunity-related functional deficits in increased risk of schizophrenia.

Interleukin-3, symptoms and cognitive deficits in first-episode drug-naïve and chronic medicated schizophrenia.

Previous studies consistently showed that IL-3 signaling may be involved in the pathophysiology of schizophrenia. However, investigations of associations between IL-3 and the neurocognitive impairments are lacking, including the study of how this may vary with stage of illness. We recruited 45 first-episode drug-naïve (FE-Sz), 35 chronic medicated schizophrenia (Ch-Sz) and 40 healthy controls (HC) and examined the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) and serum IL-3. Altered serum IL-3 levels were found in both patient groups compared with HC group (both p < 0.001). There were significantly lower neurocognitive scores on the RBANS and nearly all of its five subscales, except for Visuospatial/Constructional index in both FE-Sz and Ch-Sz patients vs healthy controls. Moreover, a significant reduction in Immediate memory index (p = 0.021) and a trend-level reduction in RBANS total score (p = 0.094) in Ch-Sz than FE-Sz patients. Interestingly, there was a significant negative correlation between IL-3 and the Immediate memory index only in Ch-Sz patients (p = 0.03). Our findings showed that neurocognitive impairments present in schizophrenia emerge during the first episode with further diminished functioning with disease progression, and IL-3 may be involved in the immediate memory deficits in the chronic phase of schizophrenia.

Ginkgo biloba and vitamin E ameliorate haloperidol-induced vacuous chewingmovement and brain-derived neurotrophic factor expression in a rat tardive dyskinesia model.

Neurodegeneration may be involved in the development of tardive dyskinesia (TD), and low levels of brain-derived neurotrophic factor (BDNF) may play a role. Ginkgo biloba (EGb761), a potent antioxidant, may have neuroprotective effects. We hypothesized that there would be decreased BDNF expression in TD, but that treatment with EGb761 would increase BDNF expression and reduce TD manifestations in a rat model. Forty rats were treated with haloperidol (2mg/kg/day via intraperitoneal injections) for 5weeks. EGb761 (50mg/kg/day) and vitamin E (20mg/kg/day) were then administered by oral gavage for another 5weeks, and we compared the effects of treatment with EGb761 or vitamin E on haloperidol-induced vacuous chewing movements (VCMs) and BDNF expression in four brain regions: prefrontal cortex (PFC), striatum (ST), substantia nigra (SNR), and globus pallidus (GP). Our results showed that haloperidol administration led to a progressive increase in VCMs, but both EGb761 and vitamin E significantly decreased VCMs. Haloperidol also decreased BDNF expression in all four brain regions, but both EGb761 and vitamin E administration significantly increased BDNF expression. Our results showed that both EGb761 and VE treatments exerted similar positive effects in a rat model of TD and increased BDNF expression levels in the four tested brain regions, suggesting that both EGb761 and vitamin E improve TD symptoms, possibly by enhancing BDNF in the brain and/or via their free radical-scavenging actions.

Beneficial effects of EGb761 and vitamin E on haloperidol-induced vacuous chewing movements in rats: Possible involvement of S100B mechanisms.

Tardive dyskinesia (TD) is a serious side effect induced by the long-term administration of typical antipsychotics. The pathophysiology of TD remains unclear, but experimental evidence suggests that neurodegeneration caused by free radicals may play an important role in TD development. S100B is considered a potential biomarker of structural neural and glial damage. This study investigated S100B expression in TD-related brain regions and assessed the effect of antioxidants Gingko biloba leaf extract (EGb761) and vitamin E (VE) on S100B in TD rats. A total of 32 rats were randomly divided into 4 study groups: saline control (saline), haloperidol alone group (Hal), EGb761-haloperidol (EGb-Hal), and vitamin E-haloperidol (VE-Hal). Rats were treated with haloperidol intraperitoneal injections (2mg/kg/day) each day for 5 weeks. EGb761 (50mg/kg/day) and VE (20mg/kg/day) were then administered during a 5-week withdrawal period. We performed behavioral assessments and immunohistochemically analyzed S100B expression in four TD-related brain regions. Our findings demonstrated that haloperidol administration led to a progressive increase in VCMs and in S100B expression in all four brain regions. Both EGb761 and VE reversed these changes, and there were no group differences between the EGb761 and VE groups. Our results indicated that long-term administration of haloperidol may induce VCMs and increase S100B expression in TD-related brain regions, and S100B may be a significant biomarker related to TD pathophysiology. Moreover, the antioxidant capacity of EGb761 and VE coupled with the possible neuroprotective effects of S100B may account for their success in improving the symptoms of haloperidol-induced TD.

Extract of Ginkgo biloba is equivalent to vitamin E in attenuating and preventing vacuous chewing movements in a rat model of tardive dyskinesia.

Free radical-mediated abnormalities may contribute toward the pathogenesis of tardive dyskinesia (TD). Many studies have reported the protective antioxidant and free radical-scavenging activities of extract of Ginkgo biloba (EGb761) against free radical-induced cell damage and dysfunction. This study aimed to compare the efficacy of EGb761 with that of vitamin E for the prevention and treatment of TD in a rat model. We carried out two studies. First, rats were injected with haloperidol (2 mg/kg intraperitoneally) daily for 5 weeks. EGb761 (50 mg/kg/day) or vitamin E (20 mg/kg/day) were then administered for another 5 weeks, and their effects on vacuous chewing movements (VCMs) were compared. Second, we compared 10 weeks of haloperidol alone with 10 weeks of haloperidol plus EGb761 or vitamin E. The administration of haloperidol led to a progressive increase in VCMs, which peaked at week 5. In study one, EGb761 and vitamin E, administered by an oral gavage for 5 weeks during withdrawal from chronic haloperidol treatment, decreased VCMs significantly, showing 83.8 and 91.0% reduction, respectively, compared with the haloperidol-alone group. In study two, the concomitant administration of EGb761 and vitamin E led to significantly fewer VCMs, by 64.4 and 73.9%, respectively, compared with the haloperidol-alone group. There was no significant difference in either study between EGb761 and vitamin E treatment. EGb761 shows promise for the prevention and treatment of TD in a rat model with a magnitude that was similar to that of vitamin E.