Glycyrrhizic acid health benefit and side effects, safety, toxicity

Glycyrrhizic acid (18beta-GL or GL) is a herbal extract with a broad spectrum of antiviral activities and pharmacological effects and multiple sites of action. Glycyrrhetinic acid is a hydrolysis product of glycyrrhizic acid, one of the main constituents of licorice root. This substance has many health benefits that are beginning to be explored.

Glycyrrhizic acid and EBV
Glycyrrhizic acid inhibits Epstein-Barr virus (EBV) infection in vitro by interfering with an early step of the EBV replication cycle.

Glycyrrhizic acid and prostate cancer
Effects of glycyrrhetinic acid and liquorice extract on cell proliferation and prostate-specific antigen secretion in LNCaP prostate cancer cells.
J Pharm Pharmacol. 2008 May. Hawthorne S, Gallagher S. School of Pharmacy, Medical Biology Centre, Queens University of Belfast, 97 Lisburn Road, Belfast BT9 7BL, UK.
Glycyrrhetinic acid is the active metabolite of glycyrrhizic acid, one of the components of liquorice extract. It has been shown to possess anti-inflammatory activity and to inhibit hepatic tumour growth. In this preliminary study, we have shown that Glycyrrhetinic acid could significantly reduce the rate of proliferation of LNCaP androgen dependent prostate cancer cells, whereas it had no effect on proliferation of PC3 and DU145 androgen-independent prostate cancer cells. Additionally, Glycyrrhetinic acid could significantly reduce the production of prostate-specific antigen by LNCaP cells maintained in-vitro.

Safety concerns with glycyrrhizic acid
Glycyrrhizic acid toxicity caused by consumption of licorice candy cigars.
CJEM. 2009 Jan;11(1): Johns C. Department of Emergency Medicine, University of Ottawa, Ottawa, Ont.
A 49-year-old female physician presented with peripheral edema, weight gain and relative hypertension caused by the consumption of licorice candy cigars containing glycyrrhizic acid found in natural licorice extract. Although the patient's response to glycyrrhizic acid resolved spontaneously, emergency physician awareness of the toxic effects of natural licorice extract may avert symptom progression in early-identified cases. The benefits of natural licorice extract as a flavour enhancer and herbal medicine are recognized worldwide. The Canadian public is likely not generally aware of the toxic potential of glycyrrhizic acid, or that it may be present in the following commonly consumed products: black licorice, chewing gum, herbal teas, soft drinks, tobaccos and herbal remedies for cough, stomach ailments and constipation. Emergency physicians should inquire about the consumption of products that may contain natural licorice extract when patients present with unexplained hypertension, hypokalemia, edema, rhabdomyolysis or myoglobinuria.

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