Quercetin Reduces Ehrlich Tumor-Induced Cancer Pain in Mice

Figure 11

Combined treatment with quercetin and morphine at doses that are ineffective as single treatment reduces Ehrlich tumor-induced pain-like responses. Mice were treated with quercetin (10 mg/kg i.p., a dose without significant analgesic effect per se), before the injection of Ehrlich tumor cells (1 × 10⁶ or 1 × 10⁷ cells, i.pl.). Mice were treated daily during 8 days and, in the 8th day, mice were treated with quercetin and after 2 h and 15 min received morphine (1 mg/kg i.p., a dose without significant analgesic effect per se). Mechanical (a) and thermal hyperalgesia (b), paw thickness (c), and overt pain-like behavior (d) were evaluated 3 h after the last quercetin treatment. Data are presented as means ± SEM of six mice per group per experiment and representative of two separated experiments: compared to the saline group, compared to the tumor group, and compared to the quercetin 10 mg/kg and morphine 1 mg/kg. One-way ANOVA followed by Tukey’s test.

(a)

(b)

(c)

(d)