Metabolomic profiles associated with a mouse model of antipsychotic-induced food intake and weight gain.

Antipsychotic drugs (AP) are used to treat a multitude of psychiatric conditions including schizophrenia and bipolar disorder. However, APs also have metabolic side effects including increased food intake and body weight, but the underlying mechanisms remain unknown. We previously reported that minocycline (MINO) co-treatment abrogates olanzapine (OLZ)-induced hyperphagia and weight gain in mice. Using this model, we investigated the changes in the pharmacometabolome in the plasma and hypothalamus associated with OLZ-induced hyperphagia and weight gain. Female C57BL/6 mice were divided into groups and fed either i) control, CON (45% fat diet) ii) CON + MINO, iii) OLZ (45% fat diet with OLZ), iv) OLZ + MINO. We identified one hypothalamic metabolite indoxylsulfuric acid and 389 plasma metabolites (including 19 known metabolites) that were specifically associated with AP-induced hyperphagia and weight gain in mice. We found that plasma citrulline, tricosenoic acid, docosadienoic acid and palmitoleic acid were increased while serine, asparagine and arachidonic acid and its derivatives were decreased in response to OLZ. These changes were specifically blocked by co-treatment with MINO. These pharmacometabolomic profiles associated with AP-induced hyperphagia and weight gain provide candidate biomarkers and mechanistic insights related to the metabolic side effects of these widely used drugs.

A Novel Synthetic Interfering Peptide Tat-3L4F Attenuates Olanzapine-Induced Weight Gain Through Disrupting Crosstalk Between Serotonin Receptor 2C and Protein Phosphatase and Tensin Homolog in Rats.

BACKGROUND: Accompanied with profound efficacy, atypical antipsychotics (AAPs) contribute to metabolic adverse effects with few effective strategies to attenuate. Serotonin 5-HT2C receptor (HTR2C) plays a critical role in hyperphagia and weight gain induced by AAPs, and expression of phosphatase tensin homolog (PTEN) in the hypothalamus also affects feeding behavior and weight change. Moreover, PTEN has a physical crosstalk between PTEN and a region in the third intracellular loop (3L4F) of the HTR2C. Tat-3L4F has the property to disrupt crosstalk between PTEN and HTR2C. This is the first study to our knowledge to investigate the effect of Tat-3L4F on olanzapine-induced metabolic abnormalities and PTEN/ phosphatidylinositol 3-kinase/protein kinase B expression in the hypothalamus in rats. METHODS: The effects of Tat-3L4F were investigated through measuring body weight, food intake, and blood glucose. In addition, PTEN/phosphatidylinositol 3-kinase/protein kinase B level in the hypothalamus was detected by immunofluorescence assay and western blot. Metabolites in the liver tissue were detected by liquid chromatography-mass spectrometry and analyzed by multivariate analyses and pairwise comparison. RESULTS: Our results showed that hyperphagia and weight gain were evident in the olanzapine alone-fed rats but was attenuated after Tat-3L4F treatment. In addition, oral glucose tolerance test indicated blood glucose at 120 minutes was higher in the olanzapine alone-treated group than in groups treated with vehicle and olanzapine + Tat-3L4F (10 µmol kg-1 per day). Furthermore, compared with olanzapine alone treatment, treatment with Tat-3L4F (10 µmol kg-1 per day) significantly inhibited PTEN expression in the hypothalamus. The olanzapine alone-treated group had the highest bile acid level, followed by the olanzapine with Tat-3L4F (1 µmol kg-1) group, olanzapine with Tat-3L4F (10 µmol kg-1) group, and vehicle group. CONCLUSIONS: Our present results reveal that Tat-3L4F is a potential pharmacological strategy for suppressing hyperphagia and weight gain induced by olanzapine, which acts through disrupting crosstalk between HTR2C and PTEN as a result of PTEN downregulation in the hypothalamus.

High-protein diet and omega-3 fatty acids improve redox status in olanzapine-treated rats.

The present study aimed to estimate the effects of high-protein diet (PD)-isolated whey protein and omega-3 fatty acids-docosahexaenoic and eicosapentaenoic acid on oxidative parameters of rats treated with Olanzapine (OLZ). Experiments were carried out on 8-week-old Wistar albino male rats (n = 64) weighing 200 ± 20 g. By dietary and pharmacological treatment, all animals were divided into 8 groups: 1. CTRL group; 2. CTRL + OLZ group; 3. CTRL + FA group; 4. CTRL + OLZ + FA group; 5. PD group; 6. PD + OLZ group; 7. PD + FA group; 8. PD + OLZ + FA group. After 6 weeks of pharmacological/diet treatment, all animals were sacrificed to collect blood samples and determine the biomarkers of oxidative stress. The following oxidative stress markers were measured spectrophotometrically: superoxide anion radical (O2-), hydrogen peroxide (H2O2), nitric oxide (NO-), index of lipid peroxidation measured as TBARS, reduced glutathione, catalase and superoxide dismutase. The study has shown that Olanzapine treatment was associated with increased release of pro-oxidants and diminished activity of anti-oxidant markers. Additional supplementation with PD and FA succeeded in abolishing the negative influence in most of the measured parameters. However, these beneficial impacts were stronger in the case of their separate application, which could be the practical and clinical importance of these results.

Up-regulation of hepatic fatty acid transporters and inhibition/down-regulation of hepatic OCTN2 contribute to olanzapine-induced liver steatosis.

Olanzapine, a representative of antipsychotics, is a first-line drug for treatment of schizophrenia. However, olanzapine-induced liver steatosis limits its clinical utilization. This study is to explore the mechanism of liver steatosis induced by olanzapine based on the regulation of transporters involved in uptake and oxidation of fatty acids. Our results revealed that 12-week oral administration of olanzapine increased hepatic triglyceride(TG), caused liver steatosis. Our further studies showed that the expression of fatty acid transporter 2(FATP2) and fatty acid binding protein 1(FABP1) were up-regulated in liver of female mice after 12-week olanzapine exposure, as well as in primary mouse hepatocytes treated with olanzapine. Olanzapine treatment also reduced hepatic ß-hydroxybutyrate level (indicator of fatty acid ß-oxidation), meanwhile, the L-carnitine (L-Car) concentration in liver of olanzapine group was significantly lower than that in control group. Further study demonstrated that both mRNA and protein expression of hepatic OCTN2 (carnitine/organic cation transporter 2) were obviously down-regulated in male mice after 12-week olanzapine treatment. Also, olanzapine markedly inhibited L-Car uptake in MDCK-hOCTN2 cells (1.06 µM of IC50), HepG2 cells and primary mouse hepatocytes. Supplementation of L-Car attenuated hepatic TG rise and improved simple steatosis in olanzapine treatment mice. Taken together, up-regulation of FATP2/FABP1 and down-regulation/inhibition of hepatic OCTN2 probably contribute to olanzapine-induced liver steatosis. Supplementation of L-Car is a promising strategy to attenuate olanzapine-induced simple steatosis.