LICORICE

Licorice or liquorice is the root of Glycyrrhiza glabra, a perennial herb that grows up to 1 mter high. The woody stems bear compound leaves and light purple or white flowers. The fruits are oblong small pods containing several seeds

Parts used

Only the dried roots (rhizomes) are used.

Phytochemicals

These are typical phytochemicals found in licorice: glabrene, liquiritin, glycyrrhizin, flavonoids.

Benefits of licorice

The phytochemical glycyrrhizin is supposed to protect he liver but scientific evidence is missing and it may even be harmful. Glycyrrhizin has following properties: antiviral, antimicrobial, anti-inflammatory, hepatoprotective and blood pressure-increasing effects.

Scientific studies about licorice

Licorice is a medicinal herb containing various bioactive components implicated in anti-toxic, anti-cancer anti-inflammatory, anti-viral and neuroprotective effects.

Detoxification
Licorice is added to moderate the characteristics of toxic herbs in Traditional Chinese Medicine, which could be partly interpreted as detoxification. Isoliquiritigenin, isolated from licorice was found to stimulate the detoxification system via Nrf2 activation, which could be a potential protective mechanism of licorice [1].
Anti-cancer
Glycyrrhetinic acid, one of the main phytochemicals of licorice has been indicated to possess potential anticancer effects and is widely utilized in hepatocellular carcinoma targeted drug delivery systems. Glycyrrhetinic acid showed a protective autophagy in hepatocellular carcinoma cells via activation of ERK. Liquoric extract was able to cure rotaviral enteritis by coordinating antiviral and anti-inflammatory effects [2]. Liquoric extract could be a viable medication for curing rotaviral enteritis in animals and humans. Scientists came to that conclusion after studying the anti-rotaviral effect of the extract in colostrums-deprived piglets after induction of rotavirus diarrhea [3]. Another Chinese study demonstrated the potential of licorice extract containing isoangustone A as an antitumor agent. Both the licorice extract and isoangustone A dose-dependently decreased DNA synthesis and induced G1 phase arrest in two types of cancer cells [4].
Anti-inflammatory
Glycyrrhetinic acid may provide hepatoprotection against chronic liver inflammation through attenuating nuclear factor-kappa B activation to alleviate the inflammation [5].
Anti-virus
Licorice is a common ingredient of several prescriptions of traditional Chinese medicine used to inhibit infection of human respiratory syncytial virus. Hot water extracts of licorice were effective against infection on airway epithelial cells by these viruses [6]. They prevented viral attachment and internalization, and stimulated stimulating interferon secretion.
Neuroprotective
Chinese researchers found that isoliquiritigenin isolated from licorice can protect dopaminergic cells under oxidative stress conditions by regulating the apoptotic process [7]. Another study demonstrated a neuroprotective effect of dehydroglyasperin C against glutamate-induced oxidative stress in mouse hippocampal cells. The phytochemical significantly reduced cytotoxicity and reactive oxygen species generation induced by glutamate [8]. Amyloid beta protein may be involved in the progression of Alzheimer's disease by acting as a neurotoxin and eliciting oxidative stress. An extract of licorice showed a protective effect against the cognitive impairments often observed in Alzheimer's disease patients. In mice this effect was mediated by antioxidant actions against oxidative stress [9].
Traditional use
Licorice is traditionally used to treat gastric ulcers, gastritis, flatulence, cough ans skin problems.

Other facts

The licorice plant is native to southern Europe, India and Central Asia. The word licorice is derived from the Greek word glukurrhiza, meaning "sweet root". The typical sweetness in licorice comes from glycyrrhizin, a sweetener wich is about 50 times sweeter than sugar but with a different sweetness profile (less instant, tart and lasting longer). Most licorice is used as a flavouring agent for tobacco products. Is is also a main ingredient of popular sweets, such as the salty licorice in the Netherlands.

Other names

Liquorice

References

[1] A protective mechanism of licorice (Glycyrrhiza uralensis): Isoliquiritigenin Stimulates detoxification system via Nrf2 activation.
J Ethnopharmacol. 2014 Dec 31.

[2] Glycyrrhetinic Acid triggers a protective autophagy by activation of extracellular regulated protein kinases in hepatocellular carcinoma cells.
J Agric Food Chem. 2014 Dec 10;62(49):11910-6

[3] Anti-rotaviral effects of Glycyrrhiza uralensis extract in piglets with rotavirus diarrhea.
Virol J. 2012 Dec 18;9:310

[4] Hexane/ethanol extract of Glycyrrhiza uralensis and its active compound isoangustone A induce G1 cycle arrest in DU145 human prostate and 4T1 murine mammary cancer cells.
J Nutr Biochem. 2012 Jan;23(1):85-92.

[5] Glycyrrhetinic acid suppressed NF-kB activation in TNF-alpha-induced hepatocytes. J Agric Food Chem. 2014 Jan 22;62(3):618-25.

[6] Water extract of licorice had anti-viral activity against human respiratory syncytial virus in human respiratory tract cell lines.
J Ethnopharmacol. 2013 Jul 9;148(2):466-73.

[7] Isoliquiritigenin isolated from licorice Glycyrrhiza uralensis prevents 6-hydroxydopamine-induced apoptosis in dopaminergic neurons.
Biosci Biotechnol Biochem. 2012;76(3):536-43.

[8] Neuroprotective effects of dehydroglyasperin C through activation of heme oxygenase-1 in mouse hippocampal cells.
J Agric Food Chem. 2012 Jun 6;60(22):5583-9.

[9] Protective effects of Glycyrrhiza uralensis Fisch. on the cognitive deficits caused by beta-amyloid peptide 25-35 in young mice. Biogerontology. 2006 Aug;7(4):239-47.