Reed root is a grass plant reed PhragmitescommunisTrin. New or dried root, is a common traditional Chinese medicine.According to the "Compendium of Materia Medica" records, reed root cold, sweet taste, into the lung, stomach meridian, has the effect of clearing heat and draining fire, producing fluid to quench thirst, eliminating boredom, stopping vomiting, diuretic, often used for fever thirst, lung heat cough, lung carbuncle spitting, stomach heat vomiting, heat and astringent pain. As a traditional Chinese medicine, Lugan has been widely used in the clinical treatment of traditional Chinese medicine.

The chemical composition, pharmacological action and clinical application of reed root were summarized in this paper.

1 Chemical composition

The chemical composition of reed root is more complex, among which polysaccharides account for a large proportion, in addition, it also contains flavonoids, anthraquinones, phenols, steroids, small molecule phenolic acids and volatile components and other components.

1 Chemical composition of Chinese medicine

The most important chemical components of reed root are polysaccharides, followed by flavonoids, steroids, anthraquinones, alkaloids, volatile components, small molecules and other components, which are as follows:

①Polysaccharides: the accharides of reed root are mainly extracted by microwave method, gel chromatography, eggshell powder column separation method, among which the eggshell powder column separation method has many advantages such as good stability, convenient elution, easy preservation, easy to make and so on.

②Steroids: reed root contains four steroid structures, including sodium-1-ene-3-ketone, 24-methyl cholesterol, cone-1,23-diene-3-ol, and 24-ethylcholesterol

③Anthraquinones: the reed root can be extracted from emodin methyl ether, which is an anthraquinone compound

④Flavonoids: reed root can be extracted to wheat flavin, belongs to a flavonoid compound

⑤Volatile composition: the fatty acid and fatty ester content of reed roots are about 25.7% determined by gas chromatography-time-of-flight mass spectrometry

⑥Small molecules: reed root can isolate gbile acid, vanillin, xiangbenzaldehyde, ferulic acid, 5-xiang methylfurfural, caffeic acid and many other small molecule compounds

⑦Alkaloids: reed root can isolate riboflavin, which is a typical alkaloid component

⑧Other categories: reed root can extract coix seed, sago cuckoo alcohol, thiamine and other chemical components

2 Pharmacological effects

At present, reed root has two main functions: liver protection and antibacterial resistance, as follows:

①liver protection:

Reed root liver effect mainly comes from its polysaccharide component, it has the effect of liver fibrosis, liver, liver injury protection experiments, found that reed root polysaccharide can significantly increase the liver cell damage effect, and reduce the toxic content of the liver, increase the liver and serum GSH-Px vitality, can peroxide oxygen into non-toxic alcohol and water, and the effect of antioxidant damage is extremely strong. In further study, it was found that liver function decline or pathological change in rats caused by CCI4 (carbon tetrachloride), but the protection of liver cells by high dose or small dose, could not only enhance liver function, but also inhibit liver fibrosis, and improve liver fat; clinically believed that small dose of polysaccharide has antioxidant function, and high dose of polysaccharide had the effect of reducing collagen content.

② antimicrobial:

In terms of antioxidant activity of liposomes, reducing force, scavenging and inhibition of free radical, it was found to have significant antioxidant activity. At the same time, relevant studies show that this drug has anti-inflammatory effects.

3 Clinical application

It is sweet and cold, and has the therapeutic effect of removing irritation, diuresis, stopping vomiting, clearing heat and reducing fire and stopping fire. At the same time, it can treat cold, bronchitis, halitosis, acute tonsil adenitis, lung abscess and other diseases, as follows:

①  Cold treatment: reed root granule for 60g, 60g, 60g, 60g xantha, 60 g, 30g, the treatment of cold has fast effect, non-toxic side effects, strong antipyretic effect and other advantages, and fresh reed root with fresh mint leaves instead of tea, can treat patients with sore throat.

② For bronchitis: traditional Chinese medicine will bronchitis included in the category of "cough", whether acute bronchitis or chronic bronchitis, application of reed root treatment, mixed infection, bacterial infection and virus infection of bronchitis patients can achieve good curative effect, thus reed root treatment bronchitis effect highly clinical recognition.

③ Treatment of halitosis: the occurrence of halitosis is related to fever, dry tongue jin, reed root sweet cold can play the effect of symptomatic treatment, the application of reed root and rock sugar decoction can effectively treat halitosis.

④ Treatment of hepatitis and cholecystitis: comprehensive reed root protection of liver, clear heat and dampness, inhibition of transaminase, yellow, anti-inflammatory, clear heat and bile, promote bile secretion and other effects, in the treatment of cholecystitis or hepatitis, can play a significant therapeutic role.

⑤ For acute tonsil adenitis: reed root and rhubarb compatibility can cure the acute phase of tonsil adenitis patients, most patients can restore normal body temperature within 12h, other patients can also eliminate acute tonsil gland inflammation within 1~2d, although some patients have transient loose stools, or abdominal pain, but the symptoms can be relieved after the toilet.

As a commonly used traditional Chinese medicine in clinical practice, reed root has a good effect on a variety of diseases. In the compound treatment of respiratory diseases, reed root is almost one of the essential drugs, which indicates that it is different from other traditional Chinese medicines and cannot be replaced by other medicinal materials. The discussion of the pharmacological effects of polysaccharides in reed root has a good antioxidant and liver protection effect. The discussion of other components is still in the primary stage, and the active components are not clear enough, so it is of special significance to explore the systematic chemical composition and pharmacological discussion of reed root.