What to know about Pueraria mirifica (kwao krua) before using it medicinally

Pueraria mirifica, commonly known as kwao krua, is a plant that has been revered for its numerous health-promoting properties, including its ability to improve cognitive function, boost fertility, and alleviate menopausal symptoms.

This herb is relatively easy to cultivate in its native habitats, thriving in well-drained soil and partial shade conditions, making it a popular choice among herb gardeners and farmers. From a botanical standpoint, Pueraria mirifica belongs to the Fabaceae family and is known for its distinctive compound leaves and purple-colored flowers.

With a rich history dating back centuries, Pueraria mirifica has been mentioned in traditional Thai medicine, with references found in ancient texts and manuscripts that highlight its medicinal value.

This article explains the medicinal, horticultural, botanical, and historical aspects of Pueraria mirifica.

What are the medicinal properties of Pueraria mirifica?

Pueraria mirifica helps with menopausal symptoms, osteoporosis, and cardiovascular diseases. Its medicinal properties include anti-inflammatory, antioxidant, and estrogenic activities. It also has antimicrobial and antifungal properties.

The active constituents of Pueraria mirifica that give its medicinal properties include miroestrol, deoxymiroestrol, and daidzein. These compounds exhibit estrogenic and phytoestrogenic activities, which are responsible for its therapeutic effects. Miroestrol, in particular, has been shown to have a higher estrogenic activity than genistein.

The roots and stems of Pueraria mirifica are the most commonly used parts for medicinal purposes. These parts are rich in the aforementioned active constituents and are traditionally used in Thai medicine to treat a variety of health conditions. The roots are also used to make tea, while the stems are used in capsule or tablet form.

Improper use of Pueraria mirifica can cause side effects such as nausea, dizziness, and stomach upset. High doses can also lead to estrogenic effects, such as breast tenderness and increased uterine bleeding. Long-term use can also cause liver damage and kidney problems.

To use Pueraria mirifica medicinally, precautions include consulting a healthcare professional before use, especially for pregnant or breastfeeding women. It is also recommended to start with low doses and gradually increase as needed. Regular liver and kidney function tests should also be performed to monitor for potential side effects.

What are the horticulural aspects of Pueraria mirifica?

Pueraria mirifica grow well in moist, tropical, and subtropical climates with temperatures between 20-30°C. It prefers well-drained acidic soils with a pH range of 6.0-7.0 and can thrive in areas with full sun to partial shade.

For optimal growth, plant kwao krua in a location with consistent moisture levels, avoiding waterlogged soils. Sow seeds 1-2 cm deep and 5-10 cm apart, allowing for proper spacing to prevent overcrowding. Mulch around the plants to retain moisture and suppress weeds.

Harvest kwao krua roots in the spring or fall, when the plant is dormant, to minimize damage to the roots. Gently dig around the base of the plant, being careful not to damage the roots. Cut the roots from the plant, leaving a small portion intact to allow for regrowth.

Pests and diseases common to kwao krua include nematodes, fungal infections like root rot, and aphid infestations. Regularly inspect plants for signs of disease or pests and treat promptly with organic or chemical controls. Maintain good sanitation practices and rotate crops to minimize the risk of infestation or infection.

What are the botanical aspects of Pueraria mirifica?

Pueraria mirifica is a climbing legume native to Thailand and Laos. It has long, slender stems, up to 10 meters in length, with compound leaves comprising 3-5 leaflets, each 7-20 cm long. The leaflets have pointed tips and wavy margins.

The taxonomical classification of Pueraria mirifica places it in the family Fabaceae, subfamily Faboideae. It belongs to the genus Pueraria, section Pueraria, and is closely related to Pueraria montana. The plant is also known as Pueraria candollei by some sources.

Pueraria mirifica has several variants, including Pueraria mirifica var. candida and Pueraria mirifica var. viridiflora. These variants differ in their leaf morphology and flower color. The plant also exhibits variability in its stem color and growth habit.

Pueraria mirifica is native to northern Thailand and Laos, where it grows in forests and along streams. The plant has been naturalized in other parts of Asia, including Vietnam and Myanmar. It typically thrives in well-drained soils and full sun to partial shade conditions.

The life cycle of Pueraria mirifica begins with seed germination, followed by seedling establishment and stem elongation. The plant produces compound leaves and inflorescences, which bear white or pink flowers. After pollination, the flowers develop into seed pods containing 4-10 seeds each, which disperse through wind and water.

What are the historical aspects of Pueraria mirifica?

Pueraria mirifica is a plant native to Thailand and Myanmar. Historically, its tubers have been used in traditional medicine for various purposes, including treating menstrual disorders and promoting longevity.

In Thai mythology, Pueraria mirifica is associated with the goddess of fertility and beauty, Nang Kwao Krua. According to legend, the plant's tubers possess mystical powers that grant women beauty, strength, and vitality.

In Thai culture, Pueraria mirifica is a symbol of femininity, fertility, and prosperity. Its tubers are often depicted in traditional art and textiles, representing the goddess's powers and attributes.

Historical texts, such as the ancient Thai medical text "Mahasiddha Samadhi Sutta", describe the use of Pueraria mirifica tubers in treating menstrual irregularities and promoting overall health. This text dates back to the 14th century.

Archaeological findings in Thailand have uncovered ceramic vessels and artifacts adorned with images of Pueraria mirifica tubers, dating back to the Ayutthaya period (14th-18th century). These artifacts suggest the plant's significance in traditional Thai culture and medicine.