What is Minophagen (generic name: glycyrrhizin)?

What is Minophagen (Glycyrrhizin)?

Minophagen is a glycyrrhizin-containing preparation administered intravenously (marketed as Stronger Neo-Minophagen C or SNMC) that has been used primarily for treating chronic hepatitis, particularly hepatitis B and C, through its anti-inflammatory, antioxidant, and immunomodulatory mechanisms. 1, 2

Primary Clinical Applications

Chronic Hepatitis Treatment

• SNMC has been used for over 30 years in Japan as a treatment for chronic hepatitis, with demonstrated efficacy in lowering serum alanine aminotransferase (ALT) levels in patients with chronic hepatitis B 2, 3
• In a randomized trial of 194 Chinese patients with chronic hepatitis B, SNMC at doses of 40-100 ml daily for 4 weeks achieved ALT normalization in 57-58% of patients, with 74-79% reaching ALT levels below 1.5 times the upper limit of normal 2
• The preparation has shown effectiveness in preventing the development of hepatocellular carcinoma in chronic hepatitis C patients, though the underlying mechanisms were historically unclear 3

Dosing Regimens

• Standard induction dosing is 40-100 ml daily intravenously for 4 weeks, followed by oral glycyrrhizin maintenance therapy (9 tablets daily for an additional 4 weeks) 2
• The 40 ml daily dose was found to be as efficient as the 100 ml dose in achieving maximal therapeutic effects 2

Mechanisms of Action

Antioxidant and Hepatoprotective Effects

• Glycyrrhizin protects hepatocytes against oxidative stress by restoring depleted cellular glutathione (GSH) and increasing expression of gamma-glutamylcysteine synthetase (γ-GCS) 3
• In transgenic mice expressing hepatitis C virus polyprotein, SNMC significantly restored serum ALT levels, hepatic malondialdehyde content, and GSH levels while attenuating mitochondrial ultrastructural damage 3
• The preparation reduces hepatic oxidative stress markers and prevents mitochondrial injury in the presence of HCV proteins 3

Anti-inflammatory and Immunomodulatory Properties

• Glycyrrhizin inhibits pro-inflammatory cytokine and chemokine expression, including CXCL10, interleukin-6, and CCL5, without interfering with natural killer cell cytolytic activity 4
• At therapeutically achievable concentrations (100 μg/ml), glycyrrhizin impairs virus-induced pro-inflammatory responses and inhibits virus-induced apoptosis 4
• The compound acts as a high-mobility group box 1 (HMGB1) inhibitor, contributing to immune regulation 5, 6

Antibacterial Activity

• Glycyrrhizin demonstrates broad-spectrum antibacterial activity by targeting bacterial enzymes, impacting cell membrane formation, and altering membrane permeability 5
• The compound bolsters host immunity by activating relevant immune pathways, thereby enhancing pathogen clearance 5
• Combining glycyrrhizin with other antibiotics reduces minimum inhibitory concentrations, potentially aiding in developing combination therapies against drug-resistant bacteria 5

Antiviral Mechanisms

• Glycyrrhizin exhibits antiviral activity against multiple viruses, including highly pathogenic H5N1 influenza A virus 4, 6
• For COVID-19, glycyrrhizin suppresses respiratory manifestations by reducing expression of angiotensin-converting enzyme 2 (ACE2), which the virus uses as an entry point 6

Safety Profile

Adverse Effects

• SNMC is generally safe, with withdrawal required in only 2% of patients due to mild and reversible side effects 2
• Common adverse effects are typically mild and self-limiting 2

Additional Therapeutic Properties

• Beyond hepatoprotection, glycyrrhizin demonstrates anticancer, antioxidant, and immune-modulatory activities in preclinical studies 6
• The compound is also widely used as a flavoring agent in foodstuffs and cosmetics 6

Important Clinical Considerations

The primary FDA-approved indication for minophagen (oral formulation) is for cavity protection 1, which differs substantially from the extensive off-label use of intravenous glycyrrhizin preparations (SNMC) in Asian countries for chronic hepatitis treatment. Clinicians should recognize this distinction between the oral dental preparation available in the United States and the intravenous hepatoprotective formulations used internationally 1, 2.