Abstract: Objective To explore the impact of berberine on serum levels of insulin resistance and cytokines in schizophrenia patients treated with risperidone. Methods Sixty-four schizophrenia patients treated with risperidone were randomized to berberine group (n=31) and control group (n=33). The fasting plasma blood glucose (FBG) and fasting insulin (Fins) were detected before and after treatment in two groups. The homeostasis model assessment for insulin resistance (HOMA-IR) was calculated. The serum levels of interleukin (IL)- 1β, IL- 6, tumor necrosis factor-alpha (TNF- α) were evaluated by enzyme linked immunosorbent assay before and after the treatment. Results Compared with control group and pre-treatment group, the levels of FBG, Fins, HOMA-IR, IL- 1β, IL- 6 and TNF- α were significantly decreased after treatment in berberine group (P < 0.05). The FBG level was significantly higher, the levels of IL-1β, IL-6 and TNF-α were significantly lower, after treatment in control group (P < 0.01). There were no significant changes in Fins and HOMA-IR after treatment (P > 0.05). There was positive correlation between HOMA-IR and IL- 1β, IL-6 and TNF-α in berberine group (r=0.316, 0.351 and 0.401, P < 0.01). Conclusion Berberine can significantly decrease FBG, Fins, HOMA-IR, IL1β, IL-6 and TNF-α levels in schizophrenia patients treated with risperidone. The HOMA-IR level is closely correlated with IL-1β, IL-6 and TNF-α levels.

Key words: schizophrenia, insulin, blood glucose, interleukin-1beta, tumor necrosis factor-alpha, berberine, insulin resistance