Setaria viridis (L.) Beauv.
Aliases：Gou Wei Cao、Guang Ming Cao、A Luo Han Cao、Gu You Zi、Mao Mao Cao、Da Wei Cao, etc.
Gouweibacao (Green Bristlegrass Herb), a Chinese medicinal, is the whole herb of Setaria viridis (L.) Beauv. [Panicum viride L.], a plant of the Poaceae family. It is also known as Gouwei Cao (Dog’s Tail Grass).
Efficacy & Actions
Clear heat and drain dampness, dispel wind and brighten the eyes, resolve toxin, and eliminate parasites.
Indications
Febrile diseases: Wind‑heat common cold, infantile liver heat. Hepatobiliary and urinary diseases: Jaundice, damp‑heat dysentery, painful urination, heat strangury. Eye diseases: Red, swollen and painful eyes, blurred vision, trachoma, corneal opacity. Skin diseases: Carbuncles, sores and tinea, common warts (verruca), urticaria, impetigo (yellow sores). Childhood diseases: Infantile malnutrition (gan accumulation), whooping cough (pertussis). Others: Toothache, stomach qi stagnation pain, cervical tuberculous lymphadenitis (scrofula), malaria (seeds).
Modern Pharmacology
Anti‑allergic and immunomodulatory: Studies have found that green bristlegrass pollen is an important allergen. Its extracts can inhibit the infiltration of inflammatory cells and the production of antibodies in the human body, thereby exerting anti‑allergic and antipruritic (itching‑relieving) effects. Anti‑inflammatory: It inhibits various inflammatory responses, providing the theoretical basis for its use in treating red, swollen and painful eyes, as well as sores and ulcers. Antibacterial: In vitro experiments have shown that its extracts inhibit certain bacteria. Neuroprotective and vasoprotective: Components such as “gramine” (禾胺) are believed to protect the skin, microvessels, and the central nervous system.
Ingredients
Polysaccharides: Setaria viridis polysaccharides (abundant, main active components). Lipids: Setaria viridis amine (gramine?), monoglycerides, diglycerides (possess certain pharmacological activities). Phenolic acids: Ferulic acid, vanillic acid, syringic acid (with herbicidal effects). Nutrients: Starch, crude protein, crude fat (provide energy and nutrition). Others: Volatile oils, and various minerals such as calcium, phosphorus, magnesium, potassium, sodium, sulfur, chlorine, etc.
Usage & Dosage
Internal use (decoction) Dosage: 6–12 g of dried herb, or 30–60 g of fresh herb per dose. Preparation: Place the herb in a clay pot, add cold water, and soak for 30 minutes. Bring to a boil over high heat, then reduce to low heat and simmer for 20 minutes. Strain the decoction, discard the residue, and take warm. External use Dosage: Appropriate amount. Preparation: Decoct in water and use the liquid to wash the affected area, or crush the fresh herb and apply directly to the affected area.
Contraindications
Use with caution in cases of spleen‑stomach deficiency cold: This herb is cool in nature; misuse may aggravate deficiency‑cold symptoms such as diarrhea and stomach pain. Contraindicated / use with caution during pregnancy: Some sources explicitly contraindicate its use during pregnancy due to lack of safety data; it should be avoided. Pollen allergy: Use with caution in individuals allergic to grass (Poaceae) pollen. Drug / food interactions: No clear reports. Avoid raw, cold, and spicy foods during use. Adverse reactions and overdose management: Conventional doses are relatively safe. Overdose may cause mild gastrointestinal discomfort. Rare allergic reactions (e.g., skin rash) may occur; discontinue use if they appear. Precautions for use: Avoid long‑term or excessive use.
Selected Formulas
1. For warts (verruca, common warts, flat warts) Method: Take fresh seed‑bearing inflorescence axis of green bristlegrass, pierce the base of the wart, and secure with adhesive tape. The wart usually falls off after about 7 days. 2. For infantile malnutrition (gan) Method: Take 9–21 g of green bristlegrass and stew with 100 g of pork liver. Drink the soup and eat the liver. Action: Strengthens the spleen and resolves food stagnation; improves malnutrition and poor appetite in children. 3. For toothache (wind‑fire toothache) Method: Take 30 g of green bristlegrass root, decoct in water, remove the residue, then add 2 eggs and cook together. Eat the eggs and drink the soup. Action: Clears heat and relieves pain. 4. For chronic poor vision (long‑term eye dimness) Method: Grind green bristlegrass into fine powder, steam it with lamb liver, and consume. Action: Nourishes the liver and brightens the eyes; improves vision. 5. For stomach qi stagnation pain and poor appetite Method: Combine green bristlegrass with other herbs (such as white olive root, osmanthus root) and stew with lean pork or chicken. Action: Regulates qi and harmonizes the stomach; strengthens the spleen and stimulates appetite. 6. For eczema and skin itching Method: Use a large amount of fresh green bristlegrass (500–6000 g), decoct in water, and wash or apply the liquid to the affected area. Action: Clears heat, resolves toxicity, removes dampness, and relieves itching. 7. For acute jaundice hepatitis (damp‑heat jaundice) Combination: Use the whole plant or inflorescence alone or in a compound formula. Action: Eliminates dampness and relieves jaundice; protects the liver.
Daily Consumption
1. Decoction Take 6–15 g dried (or 30–60 g fresh), add 500 ml water, boil then simmer for 20 minutes, strain and drink warm. Indications: Wind‑heat common cold, damp‑heat jaundice, dysentery, painful urination, red and swollen eyes. 2. Pork Liver Soup (for infantile malnutrition) 15–30 g fresh herb, 100 g pork liver. Simmer together, eat the liver and drink the soup. Action: Fortifies the spleen and resolves food stagnation. For poor appetite and emaciation in children. 3. Boiled Eggs with Root (for toothache) 30 g dried root, 2 eggs. Boil together, eat the eggs and drink the liquid. Action: Clears heat and relieves pain. For wind‑fire toothache. 4. Congee (for damp‑heat diarrhea) 30 g fresh herb, 50 g rice. Cook into congee. Action: Clears heat, drains dampness, stops diarrhea.
Medicinal Parts
Dried whole herb (including stem, leaf, spike (inflorescence), and root).
Selection & Storage
Dried product (herb): Store in a dry container in a well-ventilated, dry place, protected from moisture, mold, and insects. Fresh product (fresh herb): Wash, then place in a fresh‑keeping bag or container, and store in a refrigerator (0–4°C).