Aims: As effective herbal materials, flavonoids and the phenolic compounds are with anti-pain and anti-inflammatory effects. Based on the studies, there is a huge amount of polyphenols and flavonoids in the leaves of Morus alba L. Therefore, the aim of this study was to investigate the anti-pain effects of alcoholic extract of the leaves of Morus alba L. on the rats.

Materials & Methods: In the experimental study, 32 male Wistar rats were divided into 4 groups including control group and groups receiving 100, 200, and 400mg/kg alcoholic extract of the leaves of Morus alba L. There was 4-week daily extract gavage. The anti-pain effect of the extract was investigated through thermal hyperalgesia, writhing, tail flick, and formalin tests. Data was analyzed by SPSS 16 software using one-way ANOVA and Tukey’s post-hoc tests.

Findings: Daily use of 100, 200, and 400mg/kg of alcoholic extract of the leaves of Morus alba L. for 4 weeks led to significant increases in the mean foot withdrawal latency (p<0.001) and mean tail withdrawal latency (p<0.001) and significant reductions in the percentage of abdominal constriction (p<0.001) and pain feeling in both acute (p<0.05) and chronic (p<0.01) phases of formalin test than control group. Nevertheless, the effect of 200mg/kg dose was higher than the other doses.    

Conclusion: Oral consumption of the alcoholic extract of the leaves of Morus alba L. leads to a reduction in pain feeling in the rats. In addition, the anti-pain effect of 200mg/kg dose is higher than other doses.