Background and aims: Glycyrrhiza glabra L. (licorice) is a very sweet and soothing herb with anti-inflammatory property and hormonal effects, and in the high importance to the pharmaceutical and food industries. The aim of this study was to investigate the Anti-inflammatory and analgesic effects of extract containing and without Glycyrrhizic acid of licorice rhizome on small laboratory mice.
Methods: In this experimental study, 126 male NMRI mice randomly divided into 18 groups (n=7). Xylene and Formalin Tests used for demonstrating anti-inflammatory and antinociceptive effects. The normal saline control group and the positive control group in the inflammation test were injected dexamethasone, and morphine was injected in the pain test. Experimental groups received extract with and without Glycyrrhizic acid of licorice rhizome at doses of 20, 40, 60, 90 and 120 mg/kg. Statistical analysis was performed using Graph pad Prism software, one and two way ANOVA and Tukey’s post-hoc tests (P<0.05).
Results: The results of inflammation test showed that all doses of extract with glycyrrhizin contain anti-inflammatory effect in inhibiting the xelen-induced inflammation compared with the control group. Results of formalin test showed that the extract with glycyrrhizin has more analgesic effect than without glycyrrhizin extract. Analgesic effects of two extracts in both acute and chronic pain were observed which the pain score dropped significantly in chronic pain.
Conclusion: Findings of this study showed that licorice root extract has analgesic and anti-inflammatory effects so that major part of these effects is probably related to Glycyrrhizic acid
