What to know about Perilla frutescens (shiso) before using it medicinally

Perilla frutescens, commonly known as shiso, is an herb that has been used for centuries to promote health and well-being due to its anti-inflammatory, antioxidant, and antimicrobial properties, which have been shown to improve cardiovascular health, reduce inflammation, and boost the immune system.

Cultivated for its striking purple flowers and fragrant leaves, Perilla frutescens is a popular herb in Asian cuisine and is often used as a garnish or added to salads for its unique flavor. As a member of the mint family (Lamiaceae), Perilla frutescens has been identified as a hybrid of two other Perilla species, and its botanical properties have been studied extensively for their potential medicinal applications.

Historically, Perilla frutescens has been used in traditional medicine in China, Japan, and Korea, and has been referenced in ancient texts such as the "Shennong Bencaojing" and "Erya".

This article explains the medicinal, horticultural, botanical, and historical aspects of Perilla frutescens.

What are the medicinal properties of Perilla frutescens?

Perilla frutescens helps with various health issues, including digestive problems, inflammation, and allergies. It is used to treat nausea, diarrhea, and other gastrointestinal disorders. Shiso is also used to reduce fever and relieve headaches.

The active constituents of Perilla frutescens include perillaldehyde, limonene, and rosmarinic acid. These compounds are responsible for its medicinal properties, including anti-inflammatory, antimicrobial, and antioxidant effects. Perillaldehyde, in particular, is a key component that contributes to shiso's therapeutic benefits.

The leaves, seeds, and stems of Perilla frutescens are used for medicinal purposes. The leaves are typically dried and used as a tea or added to other herbal remedies. The seeds are used to make an oil that is applied topically to relieve skin conditions, while the stems are used to make a decoction for fever reduction.

Improper use of Perilla frutescens may cause allergic reactions, such as hives, itching, and difficulty breathing. Excessive consumption of shiso may also lead to stomach upset, nausea, and diarrhea. It is essential to consult a healthcare professional before using shiso, especially for individuals with pre-existing medical conditions.

When using Perilla frutescens medicinally, it is crucial to follow proper preparation and dosage guidelines. Pregnant and breastfeeding women should consult their healthcare provider before using shiso, as it may interact with other medications or have adverse effects on the fetus or baby. Individuals with allergies should also exercise caution when using shiso, as it may trigger allergic reactions.

What are the horticulural aspects of Perilla frutescens?

Perilla frutescens grow in full sun to partial shade, preferring well-drained soil with a pH between 6.0 and 7.0. It tolerates temperatures up to 90°F (32°C) and can survive light frosts. Average annual rainfall of 30-60 inches is suitable.

Plant Perilla frutescens in spring or fall, 1-2 weeks after the last frost. Sow seeds 1/4 inch deep and 1-2 inches apart in rows 12-18 inches apart. Water thoroughly and keep the soil consistently moist during the first 2 weeks. After that, reduce watering to about 1 inch per week.

Harvest leaves in the morning after the dew has dried, when they are at their largest. Pinch or cut the stem just above a leaf node to encourage branching. Use scissors to harvest individual leaves or stems, and harvest entire plants by cutting the stem near the base of the plant.

Common pests include aphids, whiteflies, and spider mites, while fungal diseases such as powdery mildew and leaf spot can affect the plant. Regularly inspect the plant and remove any infested or diseased leaves to prevent the problem from spreading.

What are the botanical aspects of Perilla frutescens?

Perilla frutescens is an annual or short-lived perennial herb native to Asia, characterized by oval-shaped leaves that are typically 3-10 cm long and 2-5 cm wide, with a pointed tip and a serrated margin. The leaves are dark green above and lighter below. The plant can grow up to 1 meter in height. It has small, white, or purple flowers in racemes. The leaves and stems have a distinctive fragrance.

Perilla frutescens belongs to the family Lamiaceae, which includes mint, basil, and oregano. The genus Perilla comprises four species, P. frutescens, P. nankaiensis, P. multiflorum, and P. minor. P. frutescens is further divided into two subspecies: P. f. var. frutescens and P. f. var. japonica. It is closely related to the genus Coleus.

The plant has several variants, including the green leaf form (Shiso Green) and the purple leaf form (Shiso Purple). The green leaf form is more commonly cultivated and is often used as a garnish or in salads, while the purple leaf form has a stronger flavor and aroma. Other variants include 'Ariake' and 'Katsuragi', which are popular in Japan.

Perilla frutescens is widely distributed in East Asia, including China, Japan, Korea, and Southeast Asia. It is often found growing wild in fields and along roadsides. The plant has been introduced to other parts of the world, including North America, Australia, and Europe, where it is often cultivated for its leaves and essential oil.

The life cycle of Perilla frutescens begins with germination, which typically occurs within 10-14 days after sowing seeds. The plant grows to maturity in about 6-8 weeks, producing flowers and seeds. The seeds are dispersed by wind and animals, allowing the plant to spread and colonize new areas. The plant can be harvested for its leaves and essential oil at any stage of growth.

What are the historical aspects of Perilla frutescens?

Perilla frutescens is an herb native to East Asia. In traditional Chinese medicine, it was used to treat fever, rheumatism, and as an antidote for poison. In Korean, Japanese, and Thai cuisine, it was used for flavoring, cooking, and as a garnish.

In Japanese mythology, shiso was associated with the goddess Benzaiten, who represented music, beauty, and fertility. In Thai mythology, the herb was linked to the god of wisdom, Phra Phutthamonthon. The plant's sacred status is reflected in its depiction in ancient art and literature.

In Japanese culture, shiso represented good fortune, prosperity, and longevity. In Chinese culture, the plant symbolized harmony, balance, and unity. In Thai culture, shiso was associated with wisdom, creativity, and spiritual growth.

The historical text "Shennong Ben Cao Jing" (The Divine Farmer's Herb-Root Classic) describes shiso's medicinal properties and uses. The text dates back to the 2nd century AD and is considered one of the earliest Chinese medical texts.

Artifacts depicting shiso include ancient Chinese ceramics, Japanese ukiyo-e prints, and Thai temple carvings. Examples include the Ming dynasty ceramic vessels from the 15th century AD and the 17th-century AD ukiyo-e prints of Japanese artists like Hokusai.