Chinese Licorice Extract
Also known as: Glycyrrhiza uralensis, Chinese Licorice, Gan Cao, licorice root extract, Glycyrrhiza glabra
Overview
Chinese Licorice Extract is derived from the root of *Glycyrrhiza* species, primarily *Glycyrrhiza glabra* and *Glycyrrhiza uralensis*. It is a widely recognized herbal extract, particularly prominent in Traditional Chinese Medicine (TCM), known for its distinct sweet flavor and diverse medicinal properties. The key active compound responsible for many of its effects is glycyrrhizic acid (glycyrrhizin), a triterpenoid saponin. This extract is commonly utilized for addressing gastrointestinal disorders, such as ulcerative colitis, and various liver diseases. Beyond these specific applications, it is valued for its broad anti-inflammatory, hepatoprotective, and immunomodulatory effects. In TCM, it also serves as a 'harmonizing agent' within complex herbal formulations, enhancing the efficacy and mitigating potential side effects of other herbs. Research on Chinese Licorice Extract is moderately mature, with a growing body of preclinical data and increasing clinical trial evidence, including systematic reviews and meta-analyses, supporting its traditional uses.
Benefits
Chinese Licorice Extract offers several evidence-based benefits, primarily due to its active compound, glycyrrhizic acid. It significantly improves liver function, as demonstrated by a systematic review and meta-analysis of 15 randomized controlled trials (RCTs) involving 1367 participants, which showed improved liver enzyme profiles in patients with primary liver disease. This indicates strong hepatoprotective effects. Furthermore, a meta-analysis of four studies highlighted its anti-fibrotic potential, showing that glycyrrhizic acid significantly reduced TGF-β1 mRNA expression and other related fibrosis markers, suggesting its role in mitigating liver fibrosis. For ulcerative colitis (UC), preclinical systematic reviews indicate that licorice extract and its compounds effectively reduce inflammation and pathological markers in UC models, supporting the need for further clinical trials. Beyond these primary effects, licorice exhibits notable anti-inflammatory, antioxidant, and immunomodulatory properties. It may also modulate the pharmacokinetics of co-administered drugs. Patients with liver diseases and inflammatory bowel conditions are most likely to benefit. While effect sizes vary, the improvements in liver enzymes and reductions in fibrosis markers have been statistically significant, with clinical trials typically ranging from weeks to months for benefits to manifest.
How it works
The therapeutic actions of Chinese Licorice Extract primarily stem from glycyrrhizic acid and its metabolite, glycyrrhetinic acid. These compounds exert their effects by inhibiting pro-fibrotic signaling pathways, such as the TGF-β/Smad pathway, which is crucial in the progression of liver fibrosis. They also reduce oxidative stress by scavenging free radicals and suppress the production of various inflammatory cytokines, thereby mitigating inflammation. The extract primarily interacts with the liver and gastrointestinal tract, modulating immune responses and inflammatory pathways within these systems. Glycyrrhizic acid is metabolized by intestinal bacteria to glycyrrhetinic acid, which is then absorbed into the bloodstream. Its bioavailability can vary depending on the specific formulation and the individual's gut microbiota.
Side effects
While generally safe when used appropriately, high doses or prolonged use of Chinese Licorice Extract can lead to adverse effects, primarily due to the mineralocorticoid-like effects of glycyrrhizic acid. The most common side effects include hypertension (high blood pressure), hypokalemia (low potassium levels), and edema (fluid retention). These effects are typically observed with prolonged intake exceeding 300 mg of glycyrrhizic acid daily. Less common side effects (1-5% incidence) include general gastrointestinal discomfort. Rare side effects (<1% incidence) can include allergic reactions and pseudoaldosteronism, a condition mimicking hyperaldosteronism due to the mineralocorticoid effects. Chinese Licorice Extract can interact with several medications; it may potentiate the effects of corticosteroids and diuretics, and it can affect the metabolism of other drugs by influencing cytochrome P450 enzymes. Contraindications for its use include pre-existing hypertension, hypokalemia, and pregnancy. Caution is also advised for patients with cardiovascular or renal disease due to the risk of fluid retention and electrolyte imbalance. It is crucial to monitor electrolyte levels, especially potassium, during prolonged use.
Dosage
The optimal dosage of Chinese Licorice Extract varies depending on the specific preparation and the condition being addressed. Clinical trials commonly use glycyrrhizic acid doses ranging from 50 to 200 mg per day, with 100-200 mg daily being a frequently observed optimal range in studies. Prolonged intake exceeding 300 mg of glycyrrhizic acid daily is generally discouraged due to the increased risk of adverse effects such as hypertension and hypokalemia. The extract is typically administered orally, and it can be taken with or without food. For consistent efficacy and safety, standardized extracts that specify their glycyrrhizic acid content are preferred. The absorption and metabolism of glycyrrhizic acid are influenced by the gut microbiota, which converts it to glycyrrhetinic acid. While no specific cofactors are required, monitoring electrolyte levels, particularly potassium, is advisable during extended periods of use to prevent potential imbalances.
FAQs
Is Chinese Licorice Extract safe for long-term use?
Long-term use, especially at high doses, may lead to side effects like hypertension and hypokalemia due to its mineralocorticoid effects. Short-term use under medical supervision is generally safer.
Can it be used with other medications?
Caution is advised due to potential drug interactions, particularly with corticosteroids, diuretics, and drugs metabolized by cytochrome P450 enzymes. Always consult a healthcare provider.
How soon can benefits be expected?
The time to observe benefits varies by condition. Improvements in liver function may be seen within weeks, but more complex issues like liver fibrosis reversal require longer treatment periods.
Does it cause hypertension?
Yes, high doses of glycyrrhizic acid can cause hypertension by affecting cortisol metabolism and leading to fluid and sodium retention. This is a known side effect of prolonged or excessive use.
Is it effective alone or only in combination?
Chinese Licorice Extract has shown efficacy both as a standalone treatment and as part of multi-herb formulations. Its role as a 'harmonizing agent' in TCM highlights its value in combinations.
Research Sources
- https://pubmed.ncbi.nlm.nih.gov/35671864/ – This systematic review and meta-analysis from 2022 focused on preclinical models of ulcerative colitis. It found that licorice extract and its compounds effectively reduced inflammation and pathological markers in these models, supporting its potential for clinical application in UC, despite the inherent limitations of preclinical studies.
- https://pubmed.ncbi.nlm.nih.gov/31811935/ – Published in 2020, this comprehensive review provides an overview of the phytochemicals present in licorice and their pharmacological properties. It serves as a foundational resource, detailing the chemical constituents, various pharmacological effects, and potential drug interactions of licorice.
- https://pubmed.ncbi.nlm.nih.gov/39079711/ – This systematic review and meta-analysis from 2024 included 15 RCTs (n=1367) and demonstrated that licorice formulations significantly improved liver enzyme profiles in patients with primary liver disease. The study highlights the hepatoprotective effects of licorice, noting its rigorous methodology despite some heterogeneity in formulations.
- https://www.scielo.br/j/cta/a/8BkTCwd3yPd43tqdpQ3f9NQ/ – This meta-analysis from 2022 investigated the anti-liver fibrosis effects of glycyrrhizic acid. Based on four studies, it concluded that glycyrrhizic acid significantly reduced TGF-β1 mRNA expression and other fibrosis markers, indicating its potential as an anti-fibrotic agent, despite the limited number of included studies.
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