Houttuynia cordata, commonly known as fish mint, heartleaf, or "yu xing cao" in Traditional Chinese Medicine (TCM), is a perennial herb with heart-shaped leaves and a distinct fishy aroma. Native to East and Southeast Asia, Houttuynia cordata is highly valued in traditional medicine for its anti-inflammatory, antimicrobial, and immune-boosting properties. It is also widely used as a culinary herb in certain Asian cuisines.

Botanical Classification

• Kingdom: Plantae
• Clade: Tracheophytes
• Class: Magnoliopsida
• Order: Piperales
• Family: Saururaceae
• Genus: Houttuynia
• Species: Houttuynia cordata

Plant Characteristics

Houttuynia cordata is a low-growing herb that reaches a height of 30–60 cm. It has distinctive heart-shaped leaves that vary in color from green to purplish-red, depending on light exposure. The plant produces small white flowers with a yellowish spike in late spring. Its underground rhizomes allow it to spread rapidly, making it suitable for ground cover in damp and partially shaded areas. The plant emits a strong aroma reminiscent of fish, particularly when crushed, which is why it is often referred to as fish mint.

Chemical Composition and Structure

The medicinal properties of Houttuynia cordata are attributed to its unique chemical composition, including:

• Flavonoids: Such as quercetin, hyperoside, and rutin, which are known for their anti-inflammatory and antioxidant effects.

• Alkaloids: Compounds that contribute to its antimicrobial activity, supporting its traditional use in fighting infections.

• Polysaccharides: Complex carbohydrates that help modulate the immune system and may provide general immune support.

• Volatile Oils: Including methyl-nonyl ketone and lauric acid, which give the plant its characteristic odor and contribute to its antimicrobial properties.

• Minerals and Trace Elements: Contains minerals such as potassium, calcium, and magnesium, which support cellular function and overall health.

How to Cultivate Houttuynia cordata

Cultivating Houttuynia cordata is relatively easy as it is hardy and adaptable to various conditions:

1. Climate: Thrives in warm, temperate climates but is also tolerant of cooler temperatures. Prefers partial shade but can tolerate full sun in milder climates.

2. Soil Requirements: Prefers moist, well-drained soil rich in organic matter. It can tolerate clay and sandy soils but thrives best in fertile, loamy conditions.

3. Propagation: Easily propagated from root divisions or cuttings. Rhizomes can be split and replanted to encourage growth.

4. Watering and Maintenance: Requires regular watering to keep the soil consistently moist. Mulching around the plant helps retain moisture and prevent weeds.

5. Harvesting: Leaves and stems can be harvested throughout the growing season, while the rhizomes are typically harvested in autumn. Both parts are used in culinary and medicinal applications.

Uses and Benefits

In TCM and other traditional practices, Houttuynia cordata is used for its potential health benefits, including:

• Anti-inflammatory Effects: Traditionally used to reduce inflammation, particularly in respiratory and skin conditions. Its flavonoids are believed to help mitigate inflammation and oxidative stress.

• Antimicrobial and Antiviral: Used to help fight bacterial and viral infections, particularly in cases of respiratory infections and skin issues.

• Immune Support: Polysaccharides in Houttuynia cordata may boost immune function, providing the body with additional defenses against infections.

• Respiratory Health: Often used to relieve symptoms associated with colds, sinusitis, and bronchitis, helping to clear mucus and support lung function.

• Skin Health: Applied topically for skin issues like eczema, rashes, and infections due to its soothing and antimicrobial properties.

Applications

• Medical: In TCM, Houttuynia cordata is commonly used in formulations for respiratory issues, inflammation, and infection control. It is available as a decoction, powder, or tincture and is often combined with other herbs.

• Cosmetic: Extracts of Houttuynia cordata are included in skincare products for their soothing, anti-inflammatory, and antimicrobial effects, especially useful for acne-prone and sensitive skin.

• Culinary: The leaves are used as a fresh herb in Asian cuisines, especially in salads and garnishes, where its unique flavor adds complexity to dishes.

Environmental and Safety Considerations

Houttuynia cordata is generally safe when used as directed, but large amounts can cause mild gastrointestinal discomfort in sensitive individuals. The plant’s rapid growth can become invasive in some areas, so care should be taken to contain it if planting outdoors. Sustainable cultivation practices are recommended to maintain a healthy balance in native ecosystems. As with all herbal products, individuals with allergies or sensitive skin should test for tolerance before extensive use.

References__________________________________________________________________________

Wang S, Li L, Chen Y, Liu Q, Zhou S, Li N, Wu Y, Yuan J. Houttuynia cordata thunb. alleviates inflammatory bowel disease by modulating intestinal microenvironment: a research review. Front Immunol. 2023 Nov 22;14:1306375. doi: 10.3389/fimmu.2023.1306375. PMID: 38077358; PMCID: PMC10702737.

Abstract. Houttuynia cordata Thunb (H. cordata) is a rhizomatous, herbaceous, and perennial plant widely distributed in Asia. It has multiple chemical constituents, such as alkaloids, essential oils, phenolic acids, and flavonoids used against various health problems. The essential oils and flavonoids are the main components of H. cordata that play an essential role in disease treatment and traditional health care. Moreover, the leaves and stems of H. cordata have a long medicinal history in China. In addition, H. cordata is used against several health issues, such as cold, cough, fever, pneumonia, mumps, and tumors, due to its anti-inflammatory, anti-bacterial, anti-viral, anti-oxidant, and anti-tumor effects. It protects organs due to its anti-inflammatory activity. H. cordata regulates immunity by enhancing immune barriers of the oral cavity, vagina, and gastrointestinal tract, and shows broad-spectrum activity against liver, lung, breast, and colon tumors. However, there are some gaps to be filled to understand its pathways and mechanisms. Mechanisms such as its interaction with cells, cell membranes, and various drugs are important. Studies in relation to the blood-brain barrier, lipophilicity, cAMP signaling, and skin permeability, including pharmaceutical effects, will be very useful. This review includes the biological and pharmacological activities of H. cordata based on up-to-date research.

Kim JM, Hwang IH, Jang IS, Kim M, Bang IS, Park SJ, Chung YJ, Joo JC, Lee MG. Houttuynia cordata Thunb Promotes Activation of HIF-1A-FOXO3 and MEF2A Pathways to Induce Apoptosis in Human HepG2 Hepatocellular Carcinoma Cells. Integr Cancer Ther. 2017 Sep;16(3):360-372. doi: 10.1177/1534735416670987. 

Abstract. Houttuynia cordata Thunb ( H cordata), a medicinal plant, has anticancer activity, as it inhibits cell growth and induces cell apoptosis in cancer. However, the potential anti-cancer activity and mechanism of H cordata for human liver cancer cells is not well understood. Recently, we identified hypoxia-inducible factor (HIF)-1A, Forkhead box (FOX)O3, and MEF2A as proapoptotic factors induced by H cordata, suggesting that HIF-1A, FOXO3, and MEF2A contribute to the apoptosis of HepG2 hepatocellular carcinoma cells. FOXO3 transcription factors regulate target genes involved in apoptosis. H cordata significantly increased the mRNA and protein expression of HIF-1A and FOXO3 and stimulated MEF2A expression in addition to increased apoptosis in HepG2 cells within 24 hours. Therefore, we determined the potential role of FOXO3 on apoptosis and on H cordata-induced MEF2A in HepG2 cells. HIF-1A silencing by siRNA attenuated MEF2A and H cordata-mediated FOXO3 upregulation in HepG2 cells. Furthermore, H cordata-mediated MEF2A expression enhanced caspase-3 and caspase-7, which were abolished on silencing FOXO3 with siRNA. In addition, H cordata inhibited growth of human hepatocellular carcinoma xenografts in nude mice. Taken together, our results demonstrate that H cordata enhances HIF-1A/FOXO3 signaling, leading to MEF2A upregulation in HepG2 cells, and in parallel, it disturbs the expression of Bcl-2 family proteins (Bax, Bcl-2, and Bcl-xL), which results in apoptosis. Taken together, these findings demonstrate that H cordata promotes the activation of HIF-1A-FOXO3 and MEF2A pathways to induce apoptosis in human HepG2 hepatocellular carcinoma cells and is, therefore, a promising candidate for antitumor drug development.

Kumar M, Prasad SK, Hemalatha S. A current update on the phytopharmacological aspects of Houttuynia cordata Thunb. Pharmacogn Rev. 2014 Jan;8(15):22-35. doi: 10.4103/0973-7847.125525. 

Abstract. The present review is an attempt to put an insight into a medicinal plant Houttuynia cordata Thunb, which is indigenous to North-East India and China. It is an aromatic medicinal herb belonging to family Saururaceae and is restricted to specialized moist habitats. The review provides detailed information regarding the morphology, distribution, phytochemistry, ethnopharmacological uses and also describes various pharmacological activities reported on the plant H. cordata. The review describes therapeutic efficacy of the whole plant and its extracts, fractions and isolated compounds in different diseased condition. Among the important pharmacological activities reported includes, anti-mutagenic, anti-cancer, adjuvanticity, anti-obesity, hepatoprotective, anti-viral, anti-bacterial, anti-inflammatory, free radical scavenging, anti-microbial, anti-allergic, anti-leukemic, chronic sinusitis and nasal polyps activities. Thus, the present review will act as a source of referential information to researchers to perform clinical studies on isolated compounds that may serve the society and will help in improving human health care system.

Wang S, Li L, Chen Y, Liu Q, Zhou S, Li N, Wu Y, Yuan J. Houttuynia cordata thunb. alleviates inflammatory bowel disease by modulating intestinal microenvironment: a research review. Front Immunol. 2023 Nov 22;14:1306375. doi: 10.3389/fimmu.2023.1306375. PMID: 38077358; PMCID: PMC10702737.