Su Ya (Gu Ya)
StarSetaria italica (L.) P.Beauv.
Synonyms: Panicum italicum L.
Traditionally used for
- Digestion
☯ TCM Properties
Reduces Food Stagnation, strengthens and opens the Stomach and h armonizes the Center; Strengthens the Spleen and encourages the appetite
Traditional Chinese Uses
Fructus Setariae Germinatus (Su Ya / Gu Ya) is the sprouted grain of foxtail millet Setaria italica, a sweet, warm herb that relieves food stagnation and enters the Spleen and Stomach channels. It gently reduces accumulation of starchy and grain foods, harmonizes the middle burner, and strengthens the Spleen to restore appetite, making it one of the mildest digestive herbs in the materia medica. It is favored for chronic poor appetite and indigestion rooted in Spleen deficiency, and is well suited to children, the elderly, and those recovering from illness whose digestion is fragile. It is usually decocted about 10-15 g (larger for stronger effect) and commonly combined with Mai Ya (barley sprout) to reinforce its action, or with Shan Zha and Shen Qu for broader food stagnation. It is distinct from Dao Ya, the rice sprout of Oryza sativa.
Relationships
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Botanical Description
Su Ya (also Gu Ya, 粟芽) is the sprouted, dried ripe grain of foxtail millet, Setaria italica (L.) P.Beauv. (Poaceae), an annual cereal grass cultivated throughout China and temperate Eurasia. The plant forms erect, tufted culms 0.6-1.5 m tall with flat linear leaves and a dense, bristly, cylindrical panicle bearing numerous one-flowered spikelets that mature into small rounded to ovoid yellow, orange or reddish caryopses about 1-2 mm across. To prepare the drug, cleaned mature grain is steeped in water until uniformly imbibed, then germinated in warm, moist conditions until the radicle reaches 2-5 mm, and dried. The malted grain reduces food stagnation, opens and harmonizes the Stomach, strengthens the Spleen and encourages appetite.
Cultivated as a cereal on dry farmland; wild progenitor (green foxtail) grows on disturbed, open ground.
Active Constituents
Amylase and other germination hydrolases
Enzyme (protein)Concentration: generated during germination; largely destroyed by decoction and reduced by the stir-fried (chao) preparation
The medicinal drug here is the germinated fruit (Su Ya / Gu Ya), not the raw grain, and germination is what distinguishes it. Germination of Setaria italica measurably changes the grain's composition, raising total phenolics and flavonoids and lowering antinutritional factors. Note that the enzymes cited as the rationale for the sprouted-grain drugs do not survive boiling, so an enzymatic mechanism cannot explain the effect of a decoction.
Ferulic acid
Hydroxycinnamic acid (phenolic acid)Concentration: the most abundant phenolic acid; insoluble bound forms account for roughly 75-83% of total grain phenolics
Main antioxidant phenolic of the grain. Free ferulic acid is the most bioaccessible phenolic of foxtail millet, while the bound fraction requires milling, germination or colonic hydrolysis for release.
p-Coumaric acid and isoferulic acid
Hydroxycinnamic acids (phenolic acids)Secondary phenolic acids of the pericarp with reported bioaccessibility of roughly 50-80%, contributing to the antioxidant activity of whole-grain extracts.
Prolamin (setarin) storage protein
Alcohol-soluble cereal storage protein (prolamin)Concentration: the dominant protein class of the endosperm
Prolamin isolated from cooked foxtail millet lowered blood glucose in streptozotocin-diabetic mice, which is the best-defined single-constituent activity reported for this species. Foxtail millet protein is lysine-poor, so it is not a complete protein source on its own.
⚠ Drug Interactions
Oryza sativa germinated fruit (Dao Ya) - substitution/name confusion, not a pharmacological interaction
The pinyin Gu Ya is applied to two different sprouted-grain drugs. Fructus Setariae Germinatus is the germinated fruit of Setaria italica (also called Su Ya), while Fructus Oryzae Germinatus (Dao Ya) is germinated Oryza sativa. Some suppliers and reference works label Gu Ya as rice sprout, others as millet sprout, and commercial material is sold under both Latin names. The two are separable on inspection: Setaria grains are small and near-spherical, about 2 mm, whereas rice sprouts are spindle-shaped, roughly 7-9 mm, with a longitudinal groove.
Clinical note: Specify the binomial, not the pinyin, on the prescription, and check the grain shape in the bag. Both are mild digestive agents so the clinical consequence is small, but the record should say which species was used.
Insulin and oral hypoglycaemic agents (e.g. metformin, sulfonylureas)
In a self-controlled clinical trial in subjects with impaired glucose tolerance, foxtail millet lowered postprandial glucose responses; prolamin from cooked foxtail millet was hypoglycaemic in streptozotocin-diabetic mice. These are dietary-substitution and animal data on the raw grain, not on the germinated medicinal drug, and no interaction study with any antidiabetic drug exists.
Clinical note: Irrelevant at the dose of Su Ya used in a formula. Relevant if the patient is also being advised to eat millet as a staple while on insulin or a sulfonylurea; advise self-monitoring during the changeover.
Evidence Tier
Moderate evidence · 3 studiesRecorded studies by study design, strongest design at the top. This is a study-design tier only, not a GRADE rating: it does not weigh risk of bias, consistency or precision.
Systematic review / meta-analysis
0
Randomized controlled trial
0
Other clinical trial
1
1 verified · 0 unverified
Observational / case report
0
In vitro / animal
2
1 verified · 1 unverified
Other / unclassified
0
Verified: design read from PubMed for a DOI that resolves to the cited paper Unverified: taken from the study's recorded description
Clinical Studies
The Glucose-Lowering Effect of Foxtail Millet in Subjects with Impaired Glucose Tolerance: A Self-Controlled Clinical Trial
Self-controlled trial in adults with impaired glucose tolerance in which foxtail millet improved glucose and lipid indices compared with the participants' baseline diet. Uses the raw grain of Setaria italica as a food; it does not test the germinated drug Su Ya, and the self-controlled design lacks a parallel placebo arm.
Hypoglycemic Effect of Prolamin from Cooked Foxtail Millet (Setaria italic) on Streptozotocin-Induced Diabetic Mice
Prolamin isolated from cooked foxtail millet lowered fasting blood glucose and improved insulin sensitivity in streptozotocin-diabetic mice, identifying the prolamin fraction as the carrier of the grain's hypoglycaemic activity. The species name is misspelled in the journal's printed title.
Antioxidant activity, total phenolics, flavonoids and antinutritional characteristics of germinated foxtail millet (Setaria italica)
Germination of Setaria italica grain increased total phenolics, flavonoids and antioxidant activity while reducing antinutritional factors. This is the compositional basis for treating the germinated drug (Su Ya / Gu Ya) as distinct from the raw grain.
This information is for educational purposes only and is not intended to replace professional medical advice. Always consult a qualified healthcare provider before using any herbal remedy, especially if you are pregnant, nursing, or taking medications.
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