Host-guest inclusion complex containing β-cyclodextrin and (-)-myrtenol modulates hyperalgesia, anxiety, cognitive alterations and reduce oxidative stress in a mice fibromyalgia like model

Abstract

We evaluated anti-hyperalgesic, anxiolytic and antioxidant activity of the complex containing myrtenol (MYR) and β-ciclodextrin (βCD) in fibromyalgia model (FM). The MYR/βCD complex was prepared and structurally characterized. Male Swiss mice were pretreated with MYR (50 mg/kg; p.o.), MYR/βCD (50 mg/kg; p.o.), pregabalin (PGB, 30 mg/kg; i.p) or vehicle. 1h after of treatment, the mechanical hyperalgesia, grip strength test, open field (OF), novel object recognition test (NOR), elevated plus-maze test (EPM) and some oxidative damage markers were assessed. The characterization tests indicated that MYR was incorporated into βCD. MYR/βCD had anti-hyperalgesic effect in all days of treatment and keep this activity during 6 h (p < 0.001). No difference was observed in muscle strength and OF test in MYR/βCD compared with negative control (p > 0.05). In OR test, the group MYR/ βCD spent more time in novel object to the familiar object (p < 0.05). MYR/βCD increase exploration time on open arm (p < 0.05) in EPM. MYR/βCD decrease malondialdehyde amount (p < 0.05), increased catalase activity (p < 0.05) and decreased SOD/CAT ratio when compared to control (p < 0.05). MYR/βCD promotes an anti-hyperalgesia effect for 6 h, revealed anxiolytic-like effect, inhibited cognitive and motor impairment and reduce oxidative stress.