Flaxseed
1、 Pharmacopoeia standard of flaxseed       This product is the dried and mature seed of Linum usitatissimum L., a plant of flax family. The plants were harvested when the fruits matured in autumn, dried in the sun, seeded, removed impurities, and then dried in the sun.
      [properties] this product is flat oval, one end is blunt and round, the other end is pointed and slightly skewed, 4-6mm long and 2-3mm wide. The surface is reddish brown or grayish brown, smooth and shiny, and the navel is located in the concave part of the tip; The seed ridge is light brown, located on one side of the edge. Seed coat thin, endosperm brown, membranous; Cotyledons 2, yellowish white, oily. The breath is weak, and it tastes beany when chewing.
      [identification] (1) take a small amount of this product and soak it in warm water. The mucus layer of the epidermis expands to form a transparent mucus film, which surrounds the whole seed.
      (2) Cross section of this product: the epidermal cells are large, oblong like, with mucilaginous walls, which expand in water to show lamination, and there is a cuticle outside. The lower skin is 1-5 rows of parenchymal cells with slightly thicker walls. The fiber layer is a row of closely arranged fiber cells, slightly radially extended, with a diameter of 3-5 µ m, thick wall, lignified, narrow lumen, and dimly visible laminae. Decadent layer cells were not obvious. The pigment layer is a layer of flat parenchyma cells containing brownish red substances.
      Endosperm and cotyledon cells are polygonal, containing fatty oil and aleurone particles. Aleurone particles are 7-14 µ m in diameter and contain 1-2 pseudocrystals and pseudospheres.
      (3) Take 0.5g of this product powder, put it in a test tube, add a little water, hang a trinitrophenol test paper soaked in 10% sodium carbonate solution in the test tube, plug it tightly (the test paper should not touch the powder and the tube wall), put it in a hot water bath for 3 ~ 5 minutes, and the test paper will show brick red.
      [content determination] determine according to gas chromatography (general rule 0521).
      ; Polyethylene glycol 20000 (PEG-20M) capillary column (column length: 30m, inner diameter: 0.32mm, film thickness: 0.5 µ m); Column temperature: 190 ℃; ; The split ratio was 25:1. The number of theoretical plates shall not be less than 20000 according to the peak of α - linolenic acid methyl ester.
      Preparation of reference solution   Take 150mg of linoleic acid reference substance and 150mg of α - linolenic acid reference substance respectively, weigh them accurately, put them in a conical flask, add 1ml of 10% boron trifluoride in methanol, heat them in a 60 ℃ water bath for 15 minutes, take them out, and let them cool. Add 10ml of n-octane to each accurately, shake well, and add 15ml of saturated sodium chloride solution. Accurately suck 1ml of linoleic acid n-octane and α - linolenic acid n-octane solution respectively, put them into a 5ml volumetric flask, add n-octane to the scale, and shake well.
      Preparation of test solution   . Precisely add 5ml of n-octane, shake it fully, add 20ml of saturated sodium chloride solution, take the n-octane solution, filter it, take the continuous filtrate, and get it (determined within 4 hours).
      Assay   Precisely suck 1 µ l of the reference solution and 1 µ l of the test solution respectively, inject them into the gas chromatograph, and determine.
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      Decoction pieces
      [processing] remove impurities, mash or stir fry for raw use.
      [nature, taste and meridian tropism] sweet and smooth. It belongs to lung, liver and large intestine channels.
      [functions and indications] moisten dryness and relieve constipation, nourish blood and expel wind. For intestinal dryness, constipation, dry skin, itching, hair loss.
      .
      [note] it is forbidden for those with diarrhea.
      [storage] store in a cool and dry place to prevent moths.


2、 Chemical constituents of flaxseed
The seeds contain about 30% - 40% fatty oil, and the main components of the oil are linoleic acid, linolenic acid, oleic acid,Myristic acid（myristic acid），palmitic acid（palmitic acid）， It also contains geranylgernol, a variety of steroids and triterpenoids: cholesterol,Campesterol（campesterol），Stigmasterol（stigmasterol），β - sitosterol（β-sitosterol）， The ferulic esters of △ 6-avenasterol, cy cloartenol, 24 methylene cycloartanol and eicosanol, in addition to linamarin and mucilage. Cotyledons and buds contain 9 glycosides and p-coumaric acid,caffeic acid（caffeic acid），Ferulic acid（ferulic acid），Sinapic acid(sinapic acid) esters, six carbon bonded flavonoid glycosides. Cotyledons and seedlings contained lucenin-7-rhamnoside, orientin-7-rhamnoside, isoorientin-7-glucoside.

3、 Pharmacological effects of flaxseed
1. laxative effect: the flax bitter sweet contained in this product can regulate the secretion and motor function of the small intestine. Linseed oil has a laxative effect.
2. lipid lowering effect: This product contains a large amount of unsaturated fatty acids. It has been used to prevent hyperlipidemia or atherosclerosis, but the effect is not as good as sunflower oil. Rabbits fed with linolenic acid for a long time have not significantly reduced blood lipids and improved atherosclerotic lesions.