Purslane
1、 Pharmacopoeia standard of purslane       This product is the dry aboveground part of Portulaca oleracea L., a plant of purslane family. Harvest in summer and autumn, remove residual roots and impurities, wash, steam slightly or scald and dry in the sun.
      . The stem is cylindrical, up to 30cm long, 0.1 ~ 0.2cm in diameter, with yellowish brown surface and obvious longitudinal grooves. The leaves are opposite or alternate, easily broken, complete, obovate, 1-2.5cm long and 0.5-1.5cm wide; green brown, blunt or emarginate apex, entire. The flowers are small, with 3-5 at the end of the branch, and 5 yellow petals. The capsule is conical, about 5mm long, containing most small seeds. It tastes slightly sour.
      [identification] (1) the powder of this product is grayish green. Calcium oxalate cluster crystals are numerous and of different sizes, with a diameter of 7-108 μ M. the large cluster crystals have large crystal blocks and blunt edges and corners. The calcium oxalate square crystals are 8 ～ 69 μ m wide and 125 μ m long, and some of them are stacked into clusters. The vertical walls of leaf epidermal cells are curved or straight, and the stomata are flat axis type. . The stone cells of endocarp are mostly in groups, which are long fusiform or rectangular, with slightly thick walls, and pore grooves and pits can be seen. The seed coat cells are brownish red or brownish yellow, with a polygonal star like surface and densely covered with irregular small protrusions. The pollen grains are spherical in shape, with a diameter of 48-65 μ m, with fine thorny patterns on the surface and short horizontal lines of germination pores.
      (2) Take 2G of this product powder, add 20ml of water, add formic acid to adjust the pH value to 3-4, soak for 3 hours, filter, evaporate the filtrate, add 5ml of water to dissolve the residue, and use it as the test solution. Another 2G of purslane control medicinal material was taken, and the control medicinal material solution was prepared by the same method. . In the chromatogram of the test sample, spots of the same color appear on the corresponding position of the chromatogram of the control medicinal material.
      [inspection] the moisture content shall not exceed 12.0% (the second method of general rule 0832).
      Decoction pieces
      [processing] remove impurities, wash, moisten slightly, cut into sections, and dry.
      This product has irregular sections. The stem is cylindrical, with yellowish brown surface and obvious longitudinal grooves. The leaves are mostly broken, the intact ones are obovate after flattening, and the apex is blunt or emarginate, and the whole margin. The capsule is conical and contains most small seeds. It tastes slightly sour.
      [inspection] the moisture content is the same as that of medicinal materials, and shall not exceed 9.0%.
      [identification] the same as medicinal materials.
      [nature, taste and meridian tropism] sour, cold. Return to liver and large intestine channels.
      [functions and indications] it can clear heat and detoxify, cool blood and stop bleeding, and stop dysentery. .
      [usage and dosage] 9 ～ 15g. Apply an appropriate amount to the affected area.
      [storage] store in a ventilated and dry place to prevent moisture.


2、 Chemical constituents of purslane
The whole grass contains a large amount of noradrenaline [1] and a large amount of potassium salt (including potassium nitrate, potassium chloride, potassium sulfate and other potassium salt) [2]. It also contains dopa, dopamine [1], Betanidin, isobetanidin, betanin, isobetanin [3], oxalic acid, malic acid,Citric acid anhydrous（citric acid）， Glutamic acid,L-aspartic acid （aspartic acid），L-alanineL-alanine, glucose, fructose, sucrose [4], etc. It is also reported that the reactions of alkaloids, coumarin, flavonoids, cardiac glycosides and anthracosides of the whole plant [4]. It also contains a large amount of ω 3-polyunsaturated fatty acid [6].

3、 Pharmacological effects of purslane
1. antibacterial effect qushuyan reported that purslane ethanol extract had significant inhibitory effect on Shigella and fuchsia flexneri. The water decoction has inhibitory effect on Shigella, sonnei, Schneider and Fischer dysentery bacilli, but dysentery bacilli can produce obvious drug resistance after multiple passages in purslane broth. ; It also has different inhibitory effects on some pathogenic fungi, such as tinea odonioides. It has no inhibitory effect on Mycobacterium tuberculosis; For mice infected with E. coli by intraperitoneal injection, the alcohol extract or the water decoction of the residue after alcohol extraction were ineffective. In 1992, Ma muying reported the antibacterial effect of wild purslane sold in Shenzhen vegetable market on a variety of common food contamination bacteria. The results showed that purslane had strong inhibitory effect on a variety of common food contamination bacteria. Even diluted to 12.5%, it still has certain bacteriostatic effect. In particular, it has strong antibacterial effect on many bacteria, such as Escherichia coli, Salmonella, proteus, Shigella, Staphylococcus aureus, Bacillus subtilis, Bacillus cereus and so on, but it does not inhibit xanthococcus gambiae and has no obvious inhibitory effect on Mycobacterium. Purslane also has inhibitory effect on some molds, such as Mucor racemosus, Gibberella, Alternaria, Aspergillus flavus and so on; .
2. effect on smooth muscle in 1985, qushuyan reported that purslane extract (made by decocting and concentrating with alcohol to remove the precipitate) and its isolated crystalline potassium chloride had obvious excitatory effect on the eutopic uterus of guinea pigs, rats, rabbits and dogs in vitro. Purslane injection 2ml (equivalent to crude drug 5-10g), stronger than ergonovine 0.2mg, weaker than pituitrin 10 units; While 4-6ml is similar to 10 units of pituitrin. . Since then, foreign scholar sunbhanichm and others have studied the effects of purslane fresh plant juice and boiling water extract on isolated guinea pig intestinal motility and isolated atrial and tracheal contraction. The results showed that for the isolated ileum, both water extract and boiling water extract enhanced the tension, amplitude and frequency of contraction. This effect is similar to that of acetylcholine and is dose-dependent. However, the tension of contraction and the increase in peristalsis can be slightly blocked by atropine. Both types of preparations showed dose-dependent effects on cardiac muscle contractility and contraction rate, as well as relaxation effects on isolated tracheal strips. These effects were similar to those produced by isoproterenol and could be completely blocked by propranolol (2.1x10 (-5) mol/l). The effects of Purslane on isolated ileum and atrium of guinea pigs suggest that the drug can be used as a relaxant and a cardiotonic respectively, and its bronchodilatory effect can be used to treat bronchial asthma.
3. effect on skeletal muscle: okwuasabaf equals 1987 reported that purslane water extract has unique properties of relaxing skeletal muscle in vitro and in vivo. It is effective to use this water extract locally for skeletal muscle myotonia caused by spinal cord injury. . The results showed that the effects of purslane extracts (methanol (MEE), diethyl ether (DEE) and dialyzable (DIF) extracts) were similar to those of water extract (AEE) in terms of their inhibitory effects on the unilateral diaphragm (MS and NS) of phrenic nerve and frog rectus abdominis in rats.
The three extracts all have: 3.1. produce a biphasic reaction consisting of an increase in twitch tension at the beginning followed by a long-lasting inhibition; 3.2. significantly reduce the twitching / tonic ratio of k+ and caffeine induced contractures; 3.3. contraction of rectus abdominis muscle caused by attenuation agonist nicotine. The non dialyzable (NDF) extractor showed very slight muscle relaxation without attenuating the contracture caused by the agonist nicotine. The mechanism of action can be speculated as follows: Purslane water extract and organic solvent extract produce muscle relaxation by interfering with various calcium pools, which are related to excitation contraction coupling such as starting calcium and intracellular calcium pools. Caffeine induced contraction is partly through mobilization of sarcoplasmic reticulum (SR) calcium pool, and interference with the mobilization of this calcium pool can partly explain the observed attenuation of caffeine contraction by various purslane extracts. . The intensity order of IC50 of these extracts was dif ≥ mee> DEE。 Because the partition coefficient of methanol is lower than that of ether, it is possible that the methanol extract contains more active ingredients of purslane muscle relaxation. According to the obvious effect of DIF and the fact that 100% acetonitrile extracted by high-pressure liquid chromatography has no skeletal muscle relaxation effect, it can be considered that the active ingredients of purslane may include polar components.
; One is inhibition, which is an organic component of purslane. Potassium salt mainly exists in stems, and organic components mainly exist in leaves.
5. effect on cardiovascular system: Lanzhou Medical College reported that 0.2ml of 20% water decoction had inhibitory effect on isolated frog heart. There was no significant effect on respiration, blood pressure and heartbeat of anesthetized dogs after intravenous injection of 3ml per dog.
6. ulcer healing promoting effect: according to the national collection of Chinese herbal medicine, this product is rich in vitamin A-like substances, so it can promote the physiological function of epithelial cells to be normal.
7. other effects: stefanovzh et al reported that the water-soluble and fat soluble extracts of purslane could prolong the life of rats and rabbits with severe diabetes caused by alloxan, but did not affect the blood glucose level, suggesting that purslane extract can improve the disorder of lipid metabolism.