Medicinal Value of Salvia Plebeia (Lizhicao), a Lamiaceae Plant

Salvia plebeia, a plant of the Lamiaceae family, is an uncommon Chinese medicinal herb, but physicians were already using it as medicine as early as the Ming and Qing dynasties. For example, Yu Zheng of the Chongzhen reign period of the Ming dynasty included Lizhicao in his work Huier Houfang. It was also successively included in Qing-dynasty medical works such as Bencao Congxin (New Compilation of Materia Medica), Gangmu Shiyi (Supplement to the Compendium of Materia Medica), Tianbao Bencao, and Caobian Fang.

However, because none of the above medical texts was widely known, the use of Lizhicao did not spread, and it still rarely appears in formal literature today. The Zhongyao Da Cidian (Dictionary of Chinese Materia Medica) did not include this herb; it is recorded only in Volume 19 of the Zhonghua Bencao (Chinese Materia Medica).

Although Lizhicao's name contains the word lizhi (lychee), it has no relationship to the lychee. It is a herbaceous plant that does not wither through the winter, hence its other names: Guodongqing, Geedongqing, Xueliqing, and Xuejiancao (literally "winter-green," "green through the winter," "green in snow," and "herb seen in snow"). Because its shape resembles that of a toad, people in some areas also call it Laizi cao, Laikema cao (in Hubei and Hunan, laikema means toad), Xiama cao, and Qingwa cao. In different regions it also goes by the names Shuiyang'er, Tianmingjing, Fengyan cao, Laishi cao, Pengzhang cao, Yezhu cai, and Magna cao.

Lizhicao is widely distributed throughout the country, mainly produced in Jiangsu, Zhejiang, Anhui, Hubei, and Hunan. It grows chiefly on hillsides, roadsides, wastelands, and wet riverbanks, but can also grow on plateaus at altitudes up to 2,800 meters. The Baicao Jing (Mirror of a Hundred Herbs) describes Lizhicao thus: "Lizhicao sprouts at the end of winter, does not wither through frost and snow; in March it sends up a stem nearly a foot tall, bearing fine purple flowers in spikes; it withers in May. The stem is square and hollow; the leaves are long and pointed, rough on the surface, with serrated edges; it is harvested in March." The Bencao Shiyi (Supplement to the Materia Medica) describes it as follows: "The leaves are deep blue, glossy against the light, with serrated edges; the underside is pale white, marked with fibrous veins and dotted with rough bumps, the raised and depressed areas most clearly defined. It does not wither through winter; each leaf is single-bladed, and a cluster bears dozens of leaves." These descriptions are in close agreement with Salvia plebeia R. Br. of the Lamiaceae family.

Folk records of using Lizhicao to treat illness have long existed. The Ming-dynasty Huier Houfang contains a formula called "Herb Plaster," made by pounding Lizhicao into a plaster for external application to treat luoli (lymph-node enlargement conditions). Another relatively powerful effect of Lizhicao is its ability to treat nephritic edema and ascites. Folk medicine also uses Lizhicao for acute conditions such as sore throat and ru'e (tonsillitis)—corresponding in modern medicine to acute pharyngitis, acute parotitis, tonsillitis, and epiglottitis. Lizhicao contains relatively abundant antimicrobial active constituents and therefore has some developmental value in agriculture, where it may be used as a botanical fungicide or herbicide.

According to various records, the main actions of Lizhicao are to clear heat and detoxify, cool the blood and disperse abscesses, and promote urination and reduce swelling. It can treat colds with fever, sore throat, lung-heat cough, hemoptysis, hematemesis, hematuria, metrorrhagia, hemorrhoidal bleeding, nephritic edema, white turbidity (urinary tract infection or proteinuria), dysentery, carbuncles and sores, eczema with itching, and traumatic injuries.

When used as medicine, the fresh herb may be crushed and the juice drunk directly, or the dried herb may be decocted in water and taken. The fresh herb may also be pounded and applied externally to the umbilicus, which likewise promotes diuresis and reduces swelling, and can be used to treat ascites and nephritic edema. When treating sore throat, lymph-node enlargement, and similar conditions, Lizhicao may be combined with Daqingye (Folium Isatidis), Jinyinhua (Flos Lonicerae), and Tuniuxi (Radix Achyranthis Bidentatae) to enhance the effect; to strengthen the diuretic and swelling-reducing action, it may be combined with Cheqiancao (Herba Plantaginis), Yumixu (Stigma Maydis), and Dongguapi (Exocarpium Benincasae).

Lizhicao is non-toxic; in some parts of China it is even eaten as a wild vegetable. In certain areas of Yunnan, Lizhicao is commonly used to make cold tossed salads. In some regions it has also been developed as a beverage, used together with tea. When Lizhicao is used as medicine, the fresh herb may be dosed at 15-60 g and the dried herb at 9-30 g. If used to treat ascites or nephritic edema, this dosage need not be constrained; the daily dose may exceed 500 g.