Tea leaves, a name in traditional Chinese medicine. They are the tender leaves or buds of Camellia sinensis (L.) O. Kuntze [Thea sinensis L.], a plant of the genus Camellia in the family Theaceae. They have the effects of clearing the head and eyes, relieving restlessness and thirst, aiding digestion, resolving phlegm, promoting urination, and detoxifying.It is primarily used to treat headaches, blurred vision, red eyes, excessive sleepiness, the common cold, restlessness and thirst, indigestion, bad breath, phlegm-induced wheezing, epilepsy, difficulty urinating, diarrhea and dysentery, sore throat, boils and abscesses, and burns from fire or water.
Tea Leaves
Tea leaves, a name in traditional Chinese medicine. They are the tender leaves or buds of Camellia sinensis (L.) O. Kuntze [Thea sinensis L.], a plant of the genus Camellia in the family Theaceae. They have the effects of clearing the head and eyes, relieving restlessness and thirst, aiding digestion, resolving phlegm, promoting urination, and detoxifying.It is primarily used to treat headaches, blurred vision, red eyes, excessive sleepiness, the common cold, restlessness and thirst, indigestion, bad breath, phlegm-induced wheezing, epilepsy, difficulty urinating, diarrhea and dysentery, sore throat, boils and abscesses, and burns from fire or water.
Chinese Name : 茶叶
Aliases : Bitter Tea, Tea, Ming, Dried Tea, Tea Buds, Bud Tea, Fine Tea, Laonu
Nature, Flavor & Meridian Tropism : Tastes bitter and sweet; nature is cool; enters the Heart, Lung, Stomach, and Kidney meridians
Benefits & Efficacy
Benefits
It has the effects of clearing the head and eyes, relieving restlessness and thirst, aiding digestion, resolving phlegm, promoting urination, and detoxifying.
Indications
It is primarily used to treat headaches, blurred vision, red eyes, excessive sleepiness, the common cold, restlessness and thirst, indigestion, bad breath, phlegm-induced wheezing, epilepsy, difficulty urinating, diarrhea and dysentery, sore throat, sores, boils, and burns from water or fire.
Usage and Dosage
Internal use: Decocted as a soup, 3–10 g; or incorporated into pills or powders, steeped in boiling water. External use: Ground into a powder and applied as a poultice, or pounded fresh and applied as a poultice.
Precautions
1. Those with spleen and stomach deficiency-cold should use with caution. 2. Drinking Shi Junzi tea may easily cause hiccups. 3. Excessive consumption may lead to vomiting, insomnia, and other symptoms.
Chemical Constituents
Tea primarily contains flavonoid-based tea polyphenols, mainly consisting of flavanols; purine alkaloids, primarily caffeine, account for 1–5% of the content; it also contains various triterpene saponins, essential oils, and other compounds.
Pharmacological Actions
1. Central Nervous System Stimulation: The theophylline and caffeine in tea exert a powerful stimulating effect on the central nervous system. Small doses of caffeine (85–250 mg) stimulate the cerebral cortex; as the dose increases, it can produce symptoms of central nervous system stimulation such as tension, anxiety, irritability, insomnia, tremors, and heightened sensory sensitivity. At even higher doses, it can induce convulsions. 2. Effects on the Cardiovascular System: An aqueous extract of tea increases ventricular contractility and accelerates heart rate in isolated frog and toad hearts, with the potency of the effect ranking as follows: green tea > oolong tea > black tea. Tea tannins possess high vitamin P-like activity, which enhances capillary resistance, reduces their permeability, and prevents their damage. 3.Hypotensive Effects: Hot-water extracts of green tea have a significant hypotensive effect. 4. Effects on Smooth Muscle and Skeletal Muscle: Theophylline and thearubigins can counteract bronchoconstriction induced by prostaglandin F2 (PGF2) in anesthetized guinea pigs. Black tea polyphenols and thearubigins, among others, counteract the effects of bradykinin and prostaglandins in guinea pig ileal specimens.a 10% hot-water extract of tea or tea tannins can reduce the tone and contractions of isolated rat and rabbit intestines, and exert an antispasmodic effect on spasmodic contractions induced by pilocarpine and barium chloride. 5. Diuretic Effects: The diuretic effect of tea is the result of the combined action of caffeine and theophylline; caffeine, and particularly theophylline, can inhibit renal tubular reabsorption, thereby producing a diuretic effect.Theophylline increases renal blood flow and glomerular filtration rate through its cardiotonic effects, thereby increasing the excretion of water and electrolytes; however, the increase in potassium excretion is not significant. Theophylline can enhance the effects of potent diuretics; when used in combination with carbonic anhydrase inhibitors, the diuretic effect is further enhanced. 6. Lipid-lowering and anti-atherosclerotic effects: Tea does indeed have a significant lipid-lowering effect.Replacing water with tea in the diet of rats fed a high-cholesterol diet resulted in significantly lower levels of plasma cholesterol, triglycerides, and fat content in organs and tissues compared to the control group. 7. Hypoglycemic Effects: Tea pigments can inhibit streptozotocin-induced diabetes in rats and lower blood glucose levels. This may be related to the protective effect of tea pigments in shielding β-cells from streptozotocin toxicity. 8. Inhibition of platelet aggregation and antithrombotic effects: Hot-water extracts from various teas inhibit both collagen- and ADP-induced platelet aggregation. Indanone-positive compounds extracted from tea leaves dose-dependently inhibit thrombin-induced TXB2 formation in rabbits, with an effect 40 times stronger than that of caffeine. 9. Inhibition of Nitrosamine Synthesis: Tea polyphenols and catechins are both inhibitors of N-nitrosation in tea, capable of inhibiting the N-nitrosation of proline. Green tea and black tea also inhibit endogenous N-nitrosation in the human body, and drinking them after meals is more effective than before meals. 10. Antimutagenic Effects: Green tea, oolong tea, and black tea all possess certain antimutagenic effects, with green tea and its active components demonstrating particularly strong efficacy. 11. Anticancer Effects: Tea and its extracts exhibit significant anticancer effects against various tumors in both in vitro and in vivo studies. 12. Effects of Tea on Erythropoietic Function: 1%, 3%, and 5% concentrations of white tea (White Peony, Special Grade) significantly increase serum erythropoietin levels, with the intensity of the effect correlating with tea concentration and duration of administration. 13. Other Effects: Increases white blood cell count, delays aging, kills sperm, and interferes with iron absorption in the gastrointestinal tract.
Relevant Discussions
1. *Shennong’s Classic of Dietary Therapy*: “It gives one strength and lifts the spirits.” “It treats fistulas and sores, promotes urination, reduces sleepiness, eliminates phlegm and thirst, and aids digestion of undigested food.” (Quoted from *Taiping Yulan*)
2. Hua Tuo’s *Treatise on Diet*: “Long-term consumption enhances mental clarity.” (Quoted from *Taiping Yulan*)
3. *Newly Revised Materia Medica*: “It regulates qi flow.”
4. *Dietary Therapy Materia Medica*: “Promotes bowel movements, clears heat, and resolves phlegm.”
5. *Supplement to the Materia Medica*: “Dispels miasma. Long-term consumption causes weight loss and reduces body fat.”
6. *Supplementary Notes on the Materia Medica*: “Treats heatstroke. Combined with vinegar, it is highly effective for treating diarrhea.”
7. Zhang Jiegu: “Clears the head and eyes.” (Quoted from *Ben Cao Fa Hui*)
8. *Tang Ye Ben Cao*: “Treats confusion and agitation caused by stroke.”
9. *Ri Yong Ben Cao*: “Relieves restlessness and quenches thirst; clears greasiness and refreshes the mind. When stir-fried, decocted, and drunk, it treats heat-toxin dysentery with bloody stools.”
10. *Ben Cao Gang Mu*: “When decocted to a thick consistency, it induces vomiting to expel wind-heat phlegm and saliva.”
Applications
Clinical Applications
1. For restlessness and inability to sleep following cholera: 2 qian bi of dried ginger (roasted and ground into powder) and 1 qian bi of high-quality tea powder. Combine the two ingredients with one zhan of water; first boil the tea powder until fully dissolved, then stir in the dried ginger powder and take the mixture. (*Shengji Zonglu*, Ginger-Tea Powder)
2. For food stagnation: Steep 9g of dried young tea leaves in water and drink. (*Fujian Chinese Herbal Medicine*)
3. For coughs, a sensation of a saw in the throat, and inability to sleep: 1 liang of high-quality tea powder, 1 liang of white silkworm pupae. Grind the two ingredients into a fine powder, place in a bowl, cover tightly with a cup, and pour in one small bowl of boiling water. Before bedtime, add more hot water and stir to dissolve before taking. (From *Revised Formulas of Ruizhu Hall*: Silkworm Pupae Decoction)
4. For epilepsy: 1 liang of frost-hardened old tea leaves and 5 qian of raw alum. Grind the two ingredients into a fine powder, mix with water to form pills, and coat with cinnabar. Take 3 qian per dose with boiling water. (From *Supplements to the Compendium of Materia Medica*, citing *Zhou Yisheng’s Family Treasure Formulas*)
5. For wind-phlegm-induced mania: 1 liang each of tea buds and gardenia. Decoct into a concentrated decoction and drink one bowl.Induce vomiting after a considerable time. (From *Zhai Xuan Fang*)
6. For mania caused by phlegm-fire: 120–240g of fresh, tender tea leaves. Decoct in water and take orally. (From *Fujian Chinese Herbal Medicine*)
7. For cold-induced diarrhea with white pus: 1 qian of cured tea; add a small amount of hot vinegar and mix well before taking. Take before breastfeeding or meals; adjust the dosage according to the child’s condition. (From *Comprehensive Treatise on Pediatric Hygiene and Prescriptions*)
8. For dysentery accompanied by fever and thirst: One liang each of fine tea and black plum (washed, pitted, and sun-dried). Grind into a powder, mix with raw honey, and form into pills the size of a marble. Take one pill at a time with cold water. (*Medical Mirror*: Xianmei Pills)
9. For lower back pain making it difficult to turn: Decoct five he of tea, add two he of vinegar, and take the entire dose at once. (*Dietary Therapy Materia Medica*)
10. For treating swollen abscesses: Pound fresh tea leaves into a paste and apply to the affected area. (*Hunan Materia Medica*)
11. For treating genital sores characterized by itching, pain, and yellow discharge that have not healed for a long time: Take equal parts of waxed tea and gallnut, plus a small amount of talcum powder. Grind them together into a fine powder. First, wash the affected area with whey or a decoction of scallions and pepper, then apply the powder frequently.
12. For treating soft boils: One zhan of Jian tea. Pound and sift into a fine powder; mix with oil and apply as a poultice. (Formulas 11 and 12 are from *A Selection of 101 Prescriptions*)
13. For treating sores between the toes, as well as sores on the hands and feet caused by scratching due to summer heat: Grind fine tea leaves into a powder, mix with a paste, and apply as a poultice. (*The Wonders of Health Preservation*)
Medicinal Diet Therapy
Tea Porridge
1. Benefits: Dissolves phlegm, aids digestion, promotes urination, reduces swelling, boosts energy, and refreshes the mind. Suitable for acute and chronic dysentery and enteritis.
2. Ingredients: 15 grams of tea leaves, 10 grams of japonica rice, and an appropriate amount of white sugar.
3. Preparation: Boil the tea leaves for 15 minutes to extract approximately 500 grams of concentrated tea liquid. Strain out the tea leaves, then add the japonica rice and white sugar to the concentrated tea liquid. Add about 400 grams of water and simmer until it becomes porridge.
4. Usage: Consume in two portions while still warm.
Notes
Patients requiring treatment with traditional Chinese medicine should first consult a licensed TCM hospital, where a TCM practitioner will conduct a professional pattern differentiation and issue a prescription.
Processing & Preparation
Harvesting & Processing
Leaves can be harvested after three years of cultivation. Spring and summer teas are harvested from April to June. Harvesting standards for fresh tea leaves vary by tea type; generally, black and green teas are picked as “one bud with one to two leaves,” while coarser, older teas may be picked as “one bud with four to five leaves.” Processing methods differ depending on the tea variety and can be broadly categorized into three types: fully fermented, semi-fermented, and unfermented.After fresh leaves are picked, they undergo fixation, rolling, and drying to produce green tea. Processed green tea can be scented with fragrant flowers to make scented tea. Fresh leaves undergo withering, rolling, fermentation, and drying to produce black tea. They can also be processed into tea bricks.
Storage Methods
Store in a cool, dry place.
Crude Drug Identification
Properties of Crude Drugs
The leaves are often curled into strips, thin flakes, or wrinkled. When a whole leaf is flattened, it is lanceolate to oblong, 1.5–4 cm long and 0.5–1.5 cm wide, with an acute or obtuse apex, a wedge-shaped base extending downward, and serrated margins; the serration tips are brownish-red and claw-like, sometimes falling off;Both upper and lower surfaces are pubescent; the venation is pinnately reticulate, with 4–10 pairs of lateral veins; the midrib is more prominent on the lower surface; the leaf is papery and relatively thick; the petiole is short and covered with white pubescence; mature leaves are leathery, larger, and nearly smooth; the aroma is faint and fragrant, and the taste is bitter and astringent.
Botanical Information
Botanical Classification
A species of the genus Camellia in the family Theaceae.
Morphological Characteristics
An evergreen shrub, 1–3 m tall; young branches and young leaves are finely pubescent.Simple, alternate leaves; petioles 3–7 mm long; leaf blades thin and leathery, elliptic or obovate-elliptic, 5–12 cm long, 1.8–4.5 cm wide, apex short-acuminate or obtuse, base cuneate, margin serrate, lower surface glabrous or sparsely pubescent, lateral veins about 8 pairs, distinct.Flowers are bisexual, white, fragrant, usually solitary or in pairs in the leaf axils; pedicels 6–10 mm long, curved downward; sepals 5–6, round, finely hairy, with membranous, ciliate margins, persistent; petals 5–8, broadly obovate;Numerous stamens; the filaments of the outer whorl are fused into a short tube; the ovary is superior, tomentose, and 3-chambered; the style is single, with a 3-lobed apex. The capsule is nearly spherical or flattened-triangular, with a leathery, relatively thin pericarp. Seeds are usually 1 or 2–3 in number, nearly spherical or slightly angular. Flowering occurs from October to November; fruiting occurs from October to November of the following year.
Distribution Area
Native to southern China, it is now widely cultivated throughout the Yangtze River basin and areas south of it.
Growth Habits
It prefers a warm and humid climate and is tolerant of frost but sensitive to drought, cold, waterlogging, and saline-alkali conditions. Suitable cultivation areas have an annual average temperature between 15–25°C, effective accumulated temperature (above 10°C) exceeding 3,500°C, and annual precipitation ranging from 1,000 to 2,000 mm.Tea plants can tolerate temperatures of -6 to -8°C and can even survive brief periods of temperatures as low as -30°C; growth is inhibited at around 35°C. The absolute maximum temperature is 45°C. Although tea plants can tolerate shade, high-quality products must be cultivated in full sunlight. They are best grown in yellow soil, red-yellow soil, or red soil with a pH of 4.5–5 in high mountains, hills, and flatlands; they are not suitable for planting in near-neutral or alkaline soils.
Propagation Methods
Propagation is carried out via seeds, cuttings, and layering.
Cultivation Techniques
1. Seed Propagation: With numerous varieties available, select high-quality trees. In October, when the fruits turn greenish-brown, show slight cracks, and the seed coats become hard and brittle, harvest the seeds once the cotyledons appear plump and milky white upon breaking open the seed coat. Place them in a dry, cool, and well-ventilated area to air-dry, then thresh to separate the seeds. Avoid exposure to direct sunlight and rain.Sow from October to March of the following year; fall sowing is particularly recommended. For spring sowing, store the seeds in moist sand. For row sowing, dig furrows 20 cm apart with a plant spacing of 3–4 cm; for hole sowing, dig holes 20 cm apart in rows with a spacing of 15 cm between holes, planting 3–5 seeds per hole. Seedlings can be transplanted after one year of cultivation.
2. Propagation by Cuttings: Take cuttings from March to October; secondary cuttings are preferred. Cuttings should be 3 cm long with one bud and one leaf. Dig furrows with a row spacing of 10 cm; space plants so that leaves do not overlap. Insert cuttings diagonally into the seedbed, cover with soil, press lightly, water, and provide shade. Roots generally develop within about one month.
3. Layering Propagation: Methods such as umbrella layering, mound layering, and horizontal layering can be used. Plant 2–3 cuttings per hole, fill with soil and firm it down, water, and prune off some branches and leaves.
Pest and Disease Control
1. Diseases include tea leaf blight, which can be treated by spraying a 600–800-fold dilution of 65% zinc mancozeb wettable powder or a 400-fold dilution of fungicide. Tea root-knot nematode disease is also a common pest.
2. Pests include the tea loopers, tea caterpillars, long-white scale, leaf-rolling moths, green leafhoppers, and tea mites.
