The efficacy of Licorice (Glycyrrhiza glabra) in reducing pain, as compared to other pharmacological interventions, including placebo, in recurrent aphthous stomatitis, oral lichen planus and radiation-induced oral mucositis: a systematic review

Licorice (Glycyrrhiza glabra) is one of the oldest medicinal herbs, also reported by Avicenna, with several therapeutic advantages such as wound healing, improvement of asthma, urinary infections and stomach ulcers, as well as pain-relieving characteristics. The review aims to assess the efficacy of licorice (Glycyrrhiza glabra) in reducing pain compared to other pharmacological interventions, including placebo, in recurrent aphthous stomatitis, oral lichen planus and radiation-induced oral mucositis. Four electronic databases, registries of current studies and a manual search were used to find randomized controlled trials (RCTs) that evaluated the effectiveness of licorice (Glycyrrhiza glabra) in reducing pain compared to other pharmacological interventions, including placebo, in recurrent aphthous stomatitis, oral lichen planus and radiation-induced oral mucositis patients up to December 2022. The primary outcomes were pain reduction and secondary outcomes included reduction in size of the lesion. Seven RCTs with a total of 326 patients were included. Our analysis indicated that Licorice is as effective as other pharmacological and placebo therapies in treating recurrent aphthous ulcer, oral lichen planus and oral mucositis. All of the RCTs that are included here showed a substantial decrease in visual analogue scale scores, demonstrating the efficacy of liquorice in comparison to other pharmaceutical therapies with negligible adverse effects. Thus, Licorice is a potential pain reducing herbal medicine and can be effectively used in oral lesions like RAS, OLP, radiation induced mucositis for relieving pain.