Eupatorium (Pei Lan)

Herba EupatoriiA few of eupatorium species are used medicinally. But this particular species of Eupatorium fortunei, also known as Pei Lan in Chinese-speaking countries, apparently is the most popular one, thanks to its healing properties on getting rid of bad breath. This is such a common Chinese herb that Cantonese are accustomed to using it to cook soup. Pei Lan, literally translated, means “wearable orchid” in English. It was once a very popular scented sachet because it is with an enchanting fragrance that smells like orchid, which the ancients believe can help repel foulness. Of course, eupatorium is favored more out of its medicinal uses than out of decorative purposes. In addition to cure bad breath, it is used for the treatment of dizziness, vomiting, insomnia, and so on. According to Shen Nong Ben Cao Jing (Divine Farmer’s Materia Medica), one of 3 ancient medical books admitted to the laying a foundation for traditional Chinese medicine, it is classified as a superior drug.

What is eupatorium?

Eupatorium actually refers to a genus in the family Asteraceae, in which there are from 36 to 60 different eupatorium varieties according to the classification system. The species grown in America and Europe are commonly called “Boneset”, “Hemp Agrimony”, and “Joe Pye Weed”. And there E. purpureum was also traditionally used in homeopathy for a variety of diseases, including fevers, typhus outbreaks, kidney stones, and other urinary tract problems. Likewise, eupatorium fortunei is the oriental counterpart, which however is applied for different ailments. As you can see now, eupatorium fortunei is closely connected but different from other relative plants in the same genus like eupatorium perfoliatum, eupatorium rugosum, etc.

TCM wise, the medicinal eupatorium plant mainly refers to Eupatorium fortunei Turcz. (E. japonicum Thunb. Var. fortunei (Turcz.) Pamp.; Eupatorium chinense L. var. tripartitum Miq.). And the main medicinal part is the dried aerial parts. Hence, other names of it include Herba Eupatorii, Eupatorium fortunei herb, Lan Cao, etc. In China, it is primarily produced in provinces of Jiangsu, Zhejiang, and Hebei. It is usually harvested in summer and autumn, twice a year. It is used raw or fresh.

Eupatorium fortunei is a perennial herb, 40 to 100cm in height. Roots grow broadwise. Erect stems are green or reddish purple and the lower part is shiny and hairless. Leaves are opposite; the lower ones are often wilted; the ones in the middle are with short handle, large 3-parted blade; the ones in the upper part are smaller. Capitulums align into compound corymb on the top of stems or branches. Inflorescence is 3 to 6cm in diameter; bell-shaped involucre is 6 to 7cm long; phyllary has 2 or 3 imbricate layers; each capitulum is with 4 to 6 flowers, which are tubular, white or reddish, and bisexual; syngenesious stamens are 5; pistil is 1 and with inferior ovary. Cylindrical achenes are dark brown when ripe, 5-edged, 3 to 4mm long, and with no hair and glands; white pappus is about 5mm long. Bloom and fruit time is from July to November. Habitats in the wild include roadside shrubs and riverside.

The whole weed contain 1.5% to 2.0% essential oil, which consists of p-cymene, neryl acetate, and methyl thymyl ether. Flowers and leaves contain taraxasterol, taraxasterol acetate, taraxasterol palmitate, β-amyrin palmitate, stigmasterol, β-sitosterol, octacosanol, and palmitic acid. Stems and leaves contain fumaric acid, succinic acid, mannitol, aboveground part contains lindelofine. Root contains lindelofine too.

Eupatorium health benefits

So, how to kill bad breath instantly with eupatorium? To answer this question, it is necessary to find out the answer for why do we get bad breath. Bad breath is a common ailment that is annoying and embarrassing. It tends to make people, especially the young, to be shy from coming into contact with others because of the inferiority feelings. From TCM’s point of view, apart from poor oral hygiene the typical causes of severe bad breath are the constant excessive stomach fire and the rising of damp turbidity. The usual signs and symptoms include heat in the mouth, tongue dryness, teeth tartar, swollen gums, bitter taste, greasy white tongue coating, constipation, etc. There are many ways to fight bad breath naturally. But none will get effect instantly. Either will eupatorium. However, eupatorium tea does work on reducing the production of mouth odor since this herb is known for repelling foulness. And modern pharmacological studies have shown that its extract can effectively inhibit the reproduction and growth of 12 kinds of oral bacteria that are associated with bad breath, which thereby reduces the generation of oral sulfide material.

Modern pharmacological actions of eupatorium

1. Its decoction has inhibition on corynebacterium diphtheria, Staphylococcus aureus, Sarcina, Proteus, and Salmonella typhi;
2. Its volatile oils and cymene and neryl acetate contained have direct inhibition on influenza virus;
3. Eupatorium oil and its active component called p-cymene have obvious expectorant effect by intragastric administration.

Sample eupatorium recipes on herbal remedies

The Chinese Pharmacopoeia believes that it is acrid in flavor and neutral in nature and it covers meridians of spleen, stomach, and lung. Main functions include removing dampness by means of aromatics, refreshing spleen and whetting the appetite, and relieving exterior syndrome and relieving summer-heat. Based eupatorium uses and indications are middle burner blocked by turbid dampness, a lump in the abdomen, nausea and retching, sweet greasy taste, halitosis, excessive salivation, and exterior syndrome caused by summer-heat and damp. Recommended dosage is from 3 to 9 grams or from 6 to 18 grams in fresh form.

1. Lan Cao Tang from Su Wen (Basic Questions). It is used alone to treat damp-heat spleen meridian, sweet mouth, ptyalism, ozostomia, etc.

2. Fang Xiang Hua Zhuo Tang from Shi Bing Lun (Treatise on Seasonal Diseases). It is formulated with Huo Xiang (Patchouli), Chen Pi (Citrus Peel), Zhi Ban Xia (Prepared Pinellia), Da Fu Pi (Areca Peel), Hou Po (Magnolia Bark), and fresh lotus leaves to treat mildew-damp syndrome in May and turbid pathogen;

3. Qi Ye Lu Gen Tang from Zeng Bu Ping Zhu Wen Bing Tiao Bian (Systematic Differentiation of Warm Disease with Additional Annotations). It is combined with Lu Gen (Phragmites Communis), Patchouli, Bo He (mint herb), Sang Ye (White Mulberry Leaf), Da Qing Ye (Woad Leaves), etc. to cure epidemic fever due to latent summer-dampness that is triggered by new disease.

4. Wu Ye Lu Gen Tang from Chong Ding Guang Wen Re Lun (Revised Discussion of Treatise on Feverish Diseases). It is matched with Patchouli, mint herb, lotus leaves, Pi Pa Ye (loquat leaf), Phragmites Communis, and Dong Gua (fresh watermelon) to heal initial stage of warm disease in summer, high fever, slightly chills on back, following by no chills but fever, extreme thirst, excessive sweat, dirty complexion, dry teeth, and irritation.

Eupatorium side effects and contraindications

Eupatorium fortunei contains constituents called pyrrolizidine alkaloids that are tumorigenic. Therefore, it may cause poisoning in humans, livestock, and wildlife in excessive consumption. Besides, its toxins can be excreted through breast milk, which may produce side effects to the newborn. Clinically there is no obvious side effects found in regular doses of its decoction. TCM wise, it shouldn’t be used in the cases of yin or qi deficiency.

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