Reed root
1、 Pharmacopoeia standard of reed root         This product is the fresh or dried rhizome of the gramineous plant Phragmites communis trin. It can be dug all year round to remove buds, fibrous roots and membranous leaves, and used fresh or dried in the sun.
        [character]   The fresh reed roots are long cylindrical, some slightly flat, with different lengths and diameters of 1 ~ 2cm. The surface is yellowish white, shiny, the skin is loose and peelable, the nodes are circular, and there are residual roots and bud marks. It is light, tough and not easy to break. The cutting section is yellowish white, hollow, with a wall thickness of 1 ~ 2mm, and small holes arranged in a ring. The air is weak and the taste is sweet.
        The reed roots are oblate cylindrical. The nodes are hard with longitudinal wrinkles between them.
        [identification] (1) the powder of this product is light gray brown. There are long cells and two short cells (embolic cells and siliceous cells) arranged alternately on the surface of epidermal cells; The long cells are strip-shaped, with thick and wavy walls and fine pits; Thrombocytes are crescent shaped, siliceous cells are smaller and oblate than thrombocytes. . Stone cells are mostly scattered in a single, irregular shape, some are fibrous, some have short branches, the size varies greatly, the diameter is 5-40 μ m, and the wall thickness varies. The sclerenchymal cells are rectangular or oblong in shape, with thicker walls and denser pore grooves and pits.
        (2) Take 1g of powder (fresh product is crushed after drying), add 10ml of chloroform, sonicate for 20 minutes, filter, and take the filtrate as the test solution. Another 1g of the control medicinal material of Rhizoma Phragmites was taken and made into the control medicinal material solution by the same method. Test according to thin-layer chromatography (general rule 0502), suck 10 μ l each of the above two solutions, dot them on the same silica gel G thin-layer plate, use the upper solution of petroleum ether (30 ～ 60 ℃) - ethyl formate formic acid (15:5:1) as the developing agent, develop, take out, dry, spray phosphomolybdic acid test solution, heat at 110 ℃ until the spots are clear. In the chromatogram of the test sample, fluorescent spots of the same color appear at the position corresponding to the chromatogram of the control medicinal material.
        [check]   Moisture   Not more than 12.0% (the second method of general rule 0832).
        Total ash   Not more than 11.0% (general rule 2302).
        Acid insoluble ash   .
        Decoction pieces
        [processing]   Remove impurities from fresh reed roots, wash and cut into sections.
        This product is cylindrical. The surface is yellowish white, shiny, and the nodes are circular. The cut surface is yellowish white, hollow, with small holes arranged in a ring. The air is weak and the taste is sweet.
        Remove impurities from reed roots, wash, cut into sections, and dry.
        This product has a flat cylindrical section. The surface is yellowish white, and there are longitudinal wrinkles between the nodes. .
        ; According to the hot leaching method under the determination method of water-soluble extract (general rule 2201), it shall not be less than 12.0%.
        [identification] [inspection]   Same as medicinal materials.
        [nature, taste and meridian tropism]   Gan, Han. Return to lung and stomach channels.
        ; It can clear away heat and fire, generate saliva and quench thirst, remove annoyance, stop vomiting, and diuresis. It is used for fever and thirst, lung heat and cough, lung carbuncle and purulence, stomach heat and vomiting, hot shower and pain.
        [usage and dosage] 15 ～ 30g; double the dosage of fresh products, or use for mashing juice.
        [storage] place dried reed roots in a dry place; The fresh reed roots were buried in the wet sand.


2、 Chemical constituents of reed roots
The rhizome contains more vitamins B1, B2, C and 5% protein, 1% fat, 51% carbohydrate,L-asparagine（asparamide）0.1%。 It also contains amino acids, fatty acids,sterol , tocopherol, polyphenols such ascaffeic acid(caffeic acid) andGentian acid（gentisic acid）。 It also contains 2,5-dimethoxy-p-benzoquinone, p-hydroxybenzaldehyde,Eugenol（syringaldehyde），Conifer aldehyde（coniferaldehyde），Vanillic acid（vanillic acid），Ferulic acid（ferulic acid）， P-coumaric acid and dioxanelignin. The oxidative degradation products of the latter are derivatives of guaiacyl, syringyl and 4-hydroxyphenyl of phenylpropane. In additionCoix（coixol），Triterpene,Taraxacum terpene alcohol（taraxerol），Taraxacinone(taraxerone) and a polysaccharide with a relative molecular mass of about 20000, consisting of arabinose, xylose and glucose in a molar ratio of 10:19:94. It also contains free proline and betaines.

3、 Pharmacological action of reed root
1. Coix contained in this product has inhibitory effect on skeletal muscle, can inhibit the contraction reaction caused by electrical stimulation of frog neuromuscular specimen and the oxygen uptake and anaerobic glycolysis of rat diaphragm, and can inhibit the response of actin adenosine triphosphate system, and has relatively weak central inhibitory effect, which is shown to have sedative effect on rats and mice, and can antagonize with caffeine. On the electroencephalogram of rabbits, the amplitude increases and the frequency decreases, showing that it inhibits the function of the central nervous system. In the tail electrical stimulation test of rats, it has analgesic effect, and the intensity is similar to that of aminopyrine. It has antipyretic effect, and has good antipyretic effect on the fever caused by tTG (refined complex polysaccharide of Pseu domonas fluorescens), but has little effect on the fever caused by dinitrophenol. It has a transient inhibitory effect on polysynaptic reflexes (cat peroneal nerve gastrocnemius muscle specimen). Intravenous injection can cause a transient drop in blood pressure in rabbits, subcutaneous injection can slightly reduce blood glucose, inhibit isolated toad heart and isolated rabbit intestine, and have no obvious effect on rabbit ear blood vessels. The toxicity of LMO was very low. LMO did not cause abnormal changes in mice after oral administration of 0.5g / (kg.d).
. 4mg injected into the small intestinal cavity of eutopic rabbits can slow down the peristaltic contraction. Oral administration of 2mg to rats every day can significantly increase the blood thyroxine. It has mild antioxidant effect and can prevent the oxidation of epinephrine. It has mild estrogen like effects. It also has anticancer effect, and the T / C of 6 and 12.5mg on mouse P388 is 133 and 174%.