Artesunate prevents rats from the clozapine-induced hepatic steatosis and elevation in plasma triglycerides

Abstract

Clozapine is an atypical antipsychotic with therapeutic efficacy in treatment-resistant schizophrenia patients and low incidence of extrapyramidal side effects. However, the use of clozapine has been limited by its adverse effects on metabolism. Artesunate is a semisynthetic derivative of artemisinin and was shown to decrease the plasma cholesterol and triglyceride in rabbits and rats in recent studies. The aim of this study was to examine possible effects of artesunate on the clozapine-induced metabolic alterations in rats given saline, clozapine, artesunate, or clozapine plus artesunate for 6 weeks. The clozapine group showed significantly high plasma levels of triglyceride, hepatic steatosis, and fibrosis along with high levels of C-reactive protein, alanine aminotransferase, and aspartate aminotransferase compared to the saline group. But the treatment had no effect on weight gain and caused no hyperglycemia, hyperinsulinemia, and behavioral changes in the rats. More significantly, these clozapine-induced changes were not seen in rats coadministered with clozapine plus artesunate. These results added evidence supporting psychiatrists to try add-on treatment of artesunate in schizophrenia patients to ameliorate clozapine-induced adverse metabolic effects.

Keywords: artesunate; clozapine; dyslipidemia; hepatic steatosis; schizophrenia.

Figure 1

The weight gain of rats during the 6-week experimental period. Notes: Rats were intraperitoneally given saline, clozapine (10 mg/kg/day), artesunate (3 mg/kg/day), or clozapine + artesunate for 6 weeks. Each rat was weighed at the indicated time points. Data were expressed as means ± standard error of the mean, and analyzed by two-way ANOVA, followed by one-way ANOVA and Bonferroni post-tests. *p<0.05, compared to artesunate group. Abbreviation: ANOVA, analysis of variance.

Figure 2

Artesunate prevented rats from the clozapine-induced plasma triglyceride increase. Notes: Rats were intraperitoneally given saline, clozapine, artesunate, or clozapine + artesunate for 6 weeks. At the end, the rats were deeply anesthetized with sodium pentobarbital, and blood sample was taken by intracardiac puncture and subjected to biochemical analyses for the measurement of plasma triglyceride (A) and total cholesterol (B). Data were expressed as means ± standard error of the mean, and analyzed by two-way ANOVA, followed by one-way ANOVA and Bonferroni post-tests. *p<0.05, compared to saline group. Abbreviation: ANOVA, analysis of variance.

Figure 3

Artesunate prevented rats from the clozapine-induced hepatic steatosis. Notes: Rats were intraperitoneally given saline, clozapine, artesunate, or clozapine + artesunate for 6 weeks. At the end, the rats were deeply anesthetized with sodium pentobarbital and liver sample was taken and processed for hematoxylin–eosin staining. Representative images were from saline group (A), clozapine group (B), artesunate group (C), and clozapine + artesunate group (D) rats. The arrows in image B point to intracellular vacuoles where the lipid had been cleared. 200× magnification. Abbreviation: CV, central vein.

Figure 4

Artesunate prevented rats from the clozapine-induced hepatic fibrosis. Notes: Rats were intraperitoneally given saline, clozapine, artesunate, or clozapine + artesunate for 6 weeks. At the end, the rats were deeply anesthetized with sodium pentobarbital and liver sample was taken and processed for immunohistochemical staining with the primary antibody against α-SMA. Representative images were from saline group (A), clozapine group (B), artesunate group (C), and clozapine + artesunate group (D) rats. The arrows in images point to positive α-SMA immunos-taining. 200× magnification. Abbreviation: α-SMA, α-smooth muscle actin.

Figure 5

Artesunate prevented rats from the clozapine-induced increases in plasma ALT and AST. Notes: Rats were intraperitoneally given saline, clozapine, artesunate, or clozapine + artesunate for 6 weeks. At the end, the rats were deeply anesthetized with sodium pentobarbital and blood sample was taken by intracardiac puncture and subjected to biochemical analyses for the measurement of plasma ALT (A) and AST (B). Data were expressed as means ± standard error of the mean, and analyzed by two-way ANOVA, followed by one-way ANOVA and Bonferroni post-tests. *p<0.05, compared to saline group. Abbreviations: ALT, alanine aminotransferase; ANOVA, analysis of variance; AST, aspartate aminotransferase.

Figure 6

Artesunate prevented rats from the clozapine-induced increase in plasma CRP. Notes: Rats were intraperitoneally given saline, clozapine, artesunate, or clozapine + artesunate for 6 weeks. At the end, the blood samples of rats were subjected to enzyme-linked immunosorbent assay for the measurement of plasma CRP (A), IL-1β (B), and TNF-α (C). Data were expressed as means ± standard error of the mean, and analyzed by two-way ANOVA, followed by one-way ANOVA and Bonferroni post-tests. **p<0.01, compared to saline group. Abbreviations: ANOVA, analysis of variance; CRP, C-reactive protein; IL-1β, interleukin-1β; TNF-α, tumor necrosis factor-α.