Pharmacological effects of coffee

coffee

Pinyin : Kā Fēi

Other name : coffee beans

Source of medicinal materials: The seeds of small-fruit coffee, medium-fruit coffee and large-fruit coffee of the Rubiaceae family.

Latin plant, animal and mineral name: 1. Coffea arabica L. 2. Coffeacanephora Pierre ex Froehn. 3. Coffealiberica Bul1. ex H1en

Harvesting and storage: The fruit can be harvested when the skin starts to turn red. The harvesting period varies according to the species. Small-grained species are harvested from September to November, with the peak fruiting period from September to October; medium-grained species are harvested from November to June of the following year, with the peak fruiting period from February to April. There are two processing methods: 1. Drying method: After the fresh fruit is dried in the sun or oven, the peel and seed coat are removed with a shelling machine, and impurities are sieved out.

2. Wet processing: This method is used for large-scale production. The fresh fruit is peeled with a peeling machine to separate the beans and the peel. The peeled beans are then soaked in water for degumming, washed, dried, and the seed coat is removed to obtain commercial coffee beans.

Original form 1. Small-fruited coffee, shrub or small tree, 4-7m high. Old branches are grayish white, with swollen nodes; branches are opposite, rarely three branches are in whorls. Leaves are opposite; petioles are 8-15mm long; stipules are broadly triangular, with long awl-shaped tips on the top of young branches, and sharp tips on old branches, 3-6mm long; leaves are thinly leathery, ovate-lanceolate or lanceolate, 6-14cm long, 3.5-5cm wide, with long acuminate tips, cuneate or slightly pointed bases, wavy or shallowly wavy edges, and glabrous on both sides. Cymes are clustered in leaf axils; peduncle is absent or very short; bracts are fused at base; pedicel is 0.5-1.5mm long; calyx tube is tubular, 2.5-3mm long, truncate or 5-denticulate at tip; corolla is white, length varies with variety, usually 10-18mm, 5-lobed at tip, 4 or 6-lobed, lobes longer than corolla tube; anther is 6-8mm long, exposed; style is 12-14mm long, stigma is 2-lobed. Berry is oval, 12-16mm long. Seed is raised on back. 8-10mm long. Flowering period is March-April, fruit ripening period is September-November.

2. Coffea canephora Pierre ex Froehn. Also known as: medium-grain coffee, medium-grain coffee (Flora of Hainan). The difference between this species and small-fruit coffee is that the leaves are 15-30cm long and 6-12cm wide, with an acute or broadly acute tip. The fruit is ovoid and spherical, with length and width nearly equal, both 10-12mm.

3. Big-fruited coffee Coffealiberica Bul1.exH1en Also known as: big-grained coffee, big-grained coffee (Flora of Hainan). The difference between this species and small-fruited coffee is that the leaves are larger, 15-30cm long, 6-12cm wide, with a broad and acute tip, and the holes in the vein axils on the back of the leaves are often covered with short tufts of hair. The fruit is broadly oval, 19-21m long, and 15-17mm in diameter.

Habitat Division Ecological Environment: 1. Native to tropical Africa.

2.Original to Africa.

3.Original to Africa.

Resource distribution: 1. It is introduced and cultivated in South China and Southwest my country.

2. It is cultivated in Hainan, Guangdong and other places in my country.

3. It is cultivated in Guangdong, Yunnan, Hainan and other places in my country.

Characteristics Identification: 1. The seed coat of small-fruited coffee seeds has been removed. They are oval or ovate, 8-10mm long, 5-7mm in diameter, 3-4mm thick in the middle, with a raised back and a flat belly. There are slightly curved longitudinal grooves and traces of paper-like seed coat. The raw variety is yellow or dark green; the roasted variety is dark brown, with a unique aroma and a slightly bitter taste. Astringent.

2. The seeds of the medium-fruited coffee are slightly larger, ovoid, 9-11 mm long, 7-9 mm in diameter, with a raised back and a flat ventral surface.

3. The seeds of large-fruited coffee are oblong, about 15mm long, about 10mm in diameter, and smooth.

Microscopic identification: Characteristics of Arabica coffee seed powder: The raw product is light yellow-green, and the roasted product is brown.

①There are many brown lumps of varying sizes.

②The fibers are long and thin.

③ Stone cells are rectangular or circular, up to 200μm long, 20-40μm in diameter, with obvious pores and grooves.

④ Endosperm cell walls are thick, pits are visible, and contain protein particles and fat. Physical and chemical identification Take a little powder of this product, put it on a slide, add a little water, heat it, and after the water evaporates, add 2 drops of benzene. After drying, many light yellow needle crystals can be seen along the edge of the slide. (Check for caffeine)

Chemical composition 1. The fruit of small-fruit coffee contains alkaloids, the most important of which is caffeine, followed by theobromine and theophylline. The species contains oil, among which the sterol components are: β-sitosterol, stigmasterol, campesterol, cholesterol and trace amounts of 5-avenasterol (Δ5-avenasterol), 7-avenasterol (Δ7-avenasterol), 7-stigmasterol (Δ7-stigmasterol); it also contains lipids, among which the fatty acid components are: myristic acid, palmitic acid, stearic acid, oleic acid, linoleic acid, arachidic acid. Roots and stems. The leaves and seedlings contain caffeine, theobromine, theophylline, 1,7-dimethylxanthine, scopolamine, p-hydroxybenzoic acid, vanillic acid, p-coumaric acid, ferulic acid, chlorogenic acid, and caffeic acid. The leaves also contain ursolic acid.

2. The fruit of coffee contains alkaloids: caffeine, theobromine, and theophylline. The sterol components in the seed oil include: β-sitosterol, 24-methylenecycloartanol, 5-avenoster-enol, etc. The seeds also contain caffeic acid, ferulic acid, 3-0,4-O- and 5-O-caffeoylquinic acid, 3,4-0-3,5-O- and 4,5-O-dicaffeoylquinic acid, 3-0-feruloylquinic acid, 3-0-feruloylquinic acid, 3-0-feruloyl-4-O-caffeoylquinic acid, and 3-0-caffeoyl-4-O-feruloylquinic acid.

3. The fruit of the coffee plant contains caffeic acid. The leaves also contain 1,3,7,9-tetramethyluric acid (theacrine, 1,3,7,9-tetramethyluric acid). Liberine is 0(2),1,9-trimethyluric acid [0(2),1,9-trimethyluric acid], and methyllibetine is 0(2),1,7,9-tetramethyluric acid (0(2),1,7,9-tetramethv1uric acid).

Pharmacological effects 1. Effects on the central nervous system: Caffeine, the main active ingredient of coffee, and its structural analogue theophylline have strong central nervous system excitatory effects. However, theophylline has a stronger effect than caffeine and lasts longer. People who take caffeine or drink caffeinated beverages often experience a loss of sleepiness, reduced fatigue, and a sharp mind. With increasing doses, the central nervous system excitatory effects become more obvious, resulting in tension, anxiety, restlessness, insomnia, tremors, etc. Larger doses produce local or systemic spasms. Theophylline is significantly stronger than caffeine in this regard. Methylxanthine compounds such as caffeine and theophylline can increase the sensitivity of the respiratory center to CO2. It also has an excitatory effect on the respiratory center, which is more obvious in pathological conditions such as Cheyne-Stoke respiration and premature infant apnea and when opioids are used to inhibit respiration. These compounds can also cause nausea and vomiting, which is partly related to their central effects. Taking 85-250mg of caffeine can enhance the ability to work long mental tasks and shorten reaction time, but the ability to work involving fine muscle coordination and accurate timing or arithmetic is reduced. Patients with phobias are particularly sensitive to methylxanthine compounds. In a study, most of these patients showed typical symptoms of anxiety, fear and other phobias when taking caffeine at a plasma concentration of 8μg/ml. When the central nervous system is inhibited by drugs, low doses of methylxanthine compounds such as caffeine can show obvious central excitatory effects. Other data show that such compounds can specifically counteract the effects of opioid preparations, including analgesia. Intrathecal injection of caffeine in mice without hyperalgesia can increase the half-effective dose of morphine for analgesia. However, there is no data showing that caffeine can improve brain function in alcohol poisoning. Studies have shown that long-term use of caffeine can produce tolerance and drug dependence.

2. Effects on the cardiovascular system: Caffeine, theophylline and other methylxanthine compounds have obvious effects on the circulatory system. However, their effects are complex and sometimes contradictory. This depends largely on the body's state at the time, the dosage and whether such drugs have been taken before. For people who have not used such drugs before, taking 250-350 mg of caffeine can slightly increase the heart rate, and the systolic and diastolic blood pressures also increase. However, the above doses often have no effect on people who take caffeine regularly. Whether the increase in heart rate and blood pressure caused by caffeine in people who have not taken such compounds in the past is related to compounds such as catecholamines and increased plasma renin activity remains to be further studied. However, it is currently agreed that for long-term users, the concentration of the above substances in the body does not change significantly. At high doses, both caffeine and theophylline can cause tachycardia. Sensitive patients may experience arrhythmias such as premature contractions. Excessive intake of caffeinated beverages may also cause arrhythmias, however, the risk of inducing arrhythmias in normal people is very small, and patients with ischemic heart disease or ventricular ectopy can usually tolerate moderate doses of caffeine. Methylxanthines have a constrictive effect on cerebral blood vessels, increasing cerebral vascular resistance, accompanied by a decrease in cerebral blood flow and cerebral oxygen tension.

3. Effects on smooth muscles: Methylxanthine compounds can relax various smooth muscles, the most important of which is the relaxation of tracheal smooth muscles, especially in clinical asthma and experimental use of drugs to contract tracheal smooth muscles. Theophylline is the most effective smooth muscle relaxant in this class of compounds, but its mechanism of action is still unclear. In addition, this class of compounds can specifically counteract the effects of opioids on the gastrointestinal tract.

4. Other effects: Caffeine can enhance the working capacity of human skeletal muscles and can also increase the twitch tension of cats' indirect stimulation of quadriceps. At therapeutic doses, both caffeine and theophylline can increase the contraction force of human diaphragm and reduce diaphragm fatigue. In addition, methylxanthine compounds, especially theophylline, have a diuretic effect, which increases the excretion of water and electrolytes similar to thiazide compounds. Long-term drinking of coffee can increase plasma cholesterol concentration, but this is not due to caffeine, but is related to other ingredients contained in coffee.

Toxic eye caffeine is a rare cause of death. The lethal dose of caffeine for an adult in a short period of time is about 5-10g. Taking 1g can cause adverse reactions, most commonly central nervous system and circulatory system symptoms. Early symptoms such as insomnia, restlessness and excitement develop into mild coma, vomiting, convulsions, muscle tension and tremors. Tachycardia and extrasystoles are also common. In addition, accelerated breathing can also be seen.

Identification Physical and chemical identification Take a small amount of powder of this product and place it on a glass slide, add a little water, heat it, and after the water evaporates, add 2 drops of benzene. After drying, many light yellow needle crystals can be seen along the edge of the glass slide. (Check for caffeine)

Nature and flavor: slightly bitter; astringent; flat

Functions and indications: Refreshing the mind; diuretic; stomachic. Mainly used for mental fatigue; loss of appetite

Dosage and Administration: For internal use: grind into powder and boil in water, 6-10g.

Excerpt from Chinese Materia Medica