Myrosinase from Horseradish Root Powder
Also known as: Myrosinase enzyme, β-thioglucoside glucohydrolase, Horseradish root powder enzyme, EC 3.2.1.147, Myrosinase
Overview
Myrosinase is an enzyme naturally occurring in cruciferous vegetables, notably horseradish root (*Armoracia rusticana*). Its primary function is to catalyze the hydrolysis of glucosinolates, a class of sulfur-containing compounds, into bioactive molecules such as isothiocyanates, nitriles, and thiocyanates. This conversion typically occurs when plant tissues are damaged, for instance, through chewing or cutting. In the context of supplementation, myrosinase is utilized to enhance the bioavailability and conversion of glucosinolates, whether from dietary sources like cruciferous vegetables or from concentrated extracts, into these beneficial isothiocyanates. These compounds are recognized for their potential antimicrobial, anti-inflammatory, and metabolic effects. The enzyme's activity is crucial for the formation of these biologically active compounds, but it is highly sensitive to heat and processing, which can lead to denaturation and reduced efficacy in vivo. While the biochemical characteristics of myrosinase are well-established, direct clinical evidence on the effects of isolated myrosinase supplementation in humans remains limited, with most research focusing on preclinical studies and enzymological characterization.
Benefits
Myrosinase's primary benefit lies in its ability to facilitate the conversion of glucosinolates into isothiocyanates, which are linked to several health advantages. These include potential cholesterol reduction, antimicrobial activity, and anti-inflammatory effects, as supported by preclinical and some human studies. Specifically, horseradish root preparations containing myrosinase have demonstrated antibacterial effects, particularly in urinary tract infections (UTIs). A clinical study on a combination product containing horseradish showed a trend towards reduced pyelonephritis incidence and comparable sick leave rates to antibiotics in UTI management, suggesting its role in preserving gut microbiota and reducing antibiotic use. While the statistical significance in this study was limited due to sample size, the observed effects are clinically relevant. These benefits are particularly pertinent for individuals consuming cruciferous vegetables or supplements rich in glucosinolates, as myrosinase ensures their conversion into active forms. The antimicrobial effects, for instance, can be observed within days to weeks during acute treatment periods.
How it works
Myrosinase functions as a hydrolytic enzyme that specifically targets glucosinolates. Upon contact with glucosinolates, typically when plant cells are disrupted, myrosinase catalyzes their breakdown into various biologically active compounds, primarily isothiocyanates. These isothiocyanates exert their effects by modulating key biological pathways, including the activation of detoxification enzymes and antioxidant response elements (e.g., Nrf2-mediated pathways). They also possess direct antimicrobial properties, inhibiting bacterial growth through multiple mechanisms. Isothiocyanates can influence metabolic and neurological pathways, lipid metabolism, and microbial populations within the gut and urinary tract. The presence of active myrosinase is essential for the efficient conversion of glucosinolates into absorbable isothiocyanates. If myrosinase is denatured, gut microbiota can partially compensate by hydrolyzing glucosinolates in the colon, but the efficiency of conversion may be reduced.
Side effects
Myrosinase-containing products, particularly those derived from horseradish root, are generally well-tolerated. The most commonly reported side effect is mild gastrointestinal discomfort, which may occur in some individuals. Less common side effects, affecting 1-5% of users, include possible allergic reactions or irritation, likely due to the pungent compounds naturally present in horseradish. Rare side effects, occurring in less than 1% of cases, have not been documented as serious adverse events in reviewed clinical studies. No significant drug interactions have been reported, but caution is advised when combining myrosinase-containing supplements with antibiotics or other antimicrobial agents due to potential additive effects. Contraindications include a known allergy to horseradish or other cruciferous vegetables. Data on the use of myrosinase in pregnant or lactating women are limited, so it should be used with caution in these populations. Excessive consumption of horseradish may cause mucosal irritation.
Dosage
The minimum effective dose for isolated myrosinase is not well-established, as clinical studies often utilize combination products containing horseradish with unspecified enzyme units. Optimal dosage ranges are dependent on the glucosinolate content of the co-ingested material and the specific activity of the myrosinase preparation, which can vary. While no toxic dose has been identified, excessive consumption of horseradish may lead to mucosal irritation. For best results, myrosinase should be consumed in fresh or minimally processed forms, as heat can denature the enzyme and significantly reduce its efficacy. Powdered horseradish root with active myrosinase is generally preferred over heat-treated or cooked forms. Co-ingestion with glucosinolate-rich foods is recommended to enhance isothiocyanate formation. Additionally, ascorbic acid (vitamin C) may act as a cofactor, potentially enhancing myrosinase activity.
FAQs
Is myrosinase supplementation necessary?
Supplementation may enhance isothiocyanate production from glucosinolates, especially if dietary myrosinase is inactivated by cooking, ensuring better conversion of beneficial compounds.
Is horseradish powder a reliable source?
Yes, if the horseradish powder is fresh and minimally processed, it can be a reliable source of active myrosinase, preserving its enzymatic activity.
Are there risks of consuming horseradish?
Horseradish is generally safe; however, excessive intake may cause mild gastrointestinal discomfort or mucosal irritation due to its pungent compounds.
How quickly do effects appear?
Antimicrobial effects, particularly in urinary tract infections, have been observed within days in clinical studies involving horseradish-containing products.
Does cooking destroy myrosinase?
Yes, heat denatures the myrosinase enzyme, significantly reducing its activity and the efficiency of glucosinolate conversion into isothiocyanates.
Research Sources
- https://www.frontiersin.org/journals/pharmacology/articles/10.3389/fphar.2021.767975/full – This systematic review and meta-analysis from Frontiers in Pharmacology (2021) highlights the crucial role of myrosinase in hydrolyzing glucosinolates from cruciferous vegetables into bioactive compounds like isothiocyanates. It discusses how these compounds influence cholesterol and metabolic pathways, primarily based on rodent models. The review emphasizes factors affecting glucosinolate content and myrosinase activity but notes the limited human randomized controlled trial data on isolated myrosinase supplementation.
- https://pmc.ncbi.nlm.nih.gov/articles/PMC11591416/ – A clinical study published in PMC (2024) investigated Angocin®, a combination of nasturtium herb and horseradish root, for managing acute and recurrent urinary tract infections. The study, involving over 30 participants per group, showed comparable sick leave rates to antibiotics and a trend towards reduced pyelonephritis incidence. The observed antibacterial and anti-inflammatory effects were partly attributed to the myrosinase-mediated isothiocyanate production from horseradish, despite limitations such as low event rates and lack of blinding.
- https://pubmed.ncbi.nlm.nih.gov/15922609/ – This biochemical characterization study (2005) focused on purifying and characterizing myrosinase from horseradish root. It detailed the enzyme's kinetics, molecular structure, and its dependence on cofactors like ascorbic acid. This foundational enzymology research provides a deeper understanding of myrosinase's role in glucosinolate metabolism but does not offer clinical efficacy data.