Preprint / Version 1

Liquorice for pain?

Authors

  • Rae Bell Emerita) Regional Centre of Excellence in Palliative Care, Haukeland University Hospital, Jonas Lies vei 65, Bergen 5021, Norway
  • Vânia Moreira Laboratory of Pharmaceutical Chemistry, Faculty of Pharmacy, University of Coimbra, Coimbra, Portugal
  • Eija Kalso Department of Pharmacology and SleepWell Research Programme, Faculty of Medicine, University of Helsinki and Department of Anaesthesiology, Intensive Care and Pain Medicine, Helsinki University Hospital, Helsinki, Finland
  • Jari Yli-Kauhaluoma Drug Research Program, Division of Pharmaceutical Chemistry and Technology, Faculty of Pharmacy, University of Helsinki, Helsinki, Finland

Keywords:

glycyrrhizin, inflammation, liquorice, pain

Abstract

Liquorice has a long history of use in traditional Chinese, Ayurvedic and herbal medicine. The liquorice plant contains numerous bioactive compounds, including triterpenes, flavonoids and secondary metabolites, with glycyrrhizin being the main active compound. Liquorice constituents have been found to have anti-inflammatory, antioxidant, antiviral, anticancer, hepatoprotective and neuroprotective properties. In addition, they appear to have antidepressant actions and effects on morphine tolerance. Glycyrrhizin, its metabolite glycyrrhetic (glycyrrhetinic) acid and other liquorice-derived compounds such as isoflavonoids and trans-chalcones, exert potent anti-inflammatory effects via a wide range of mechanisms including high mobility group box 1 protein (HMGB1) inhibition, gap junction blockade and α2A-adrenoceptor antagonism. These properties, together with an increasing body of preclinical studies and a long history of use in herbal medicine, suggest that liquorice constituents may be useful for pain management. Glycyrrhizin is used widely in the confectionary, food and tobacco industries, but has documented adverse effects that may limit clinical use. Whether liquorice plant-derived compounds represent a novel class of analgesics is yet to be established. Having a host of bioactive compounds with a broad range of mechanisms of effect, liquorice is a plant that, in the future, may give rise to new therapies for pain. Keywords: glycyrrhizin, inflammation, liquorice, pain

Author Biography

Vânia Moreira, Laboratory of Pharmaceutical Chemistry, Faculty of Pharmacy, University of Coimbra, Coimbra, Portugal

Drug Research Program, Division of Pharmaceutical Chemistry and Technology, Faculty of Pharmacy, University of Helsinki, Helsinki, Finland

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