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This product is the dried bark and root bark of Melia toosendan sieb. et zucc. or Melia azedarach L. Peel and dry in spring and autumn, or remove the coarse skin and dry in the sun.
[properties] the product is irregular plate-shaped, grooved or semi roll shaped, with different length and width, and 2-6mm thick. The outer surface is grayish brown or grayish brown, rough, with intertwined longitudinal wrinkles and dot shaped grayish brown lenticels, and light yellow after removing the coarse skin; The inner surface is off white or light yellow. It is tough, not easy to break, fibrous in cross section, lamellar and easy to peel off. The breath is slight and the taste is bitter.
[identification] (1) take a section of this product, fold and knead it by hand, and it can be divided into multiple layers of flakes, with yellow and white layers, and each layer of flakes has very fine reticulation.
(2) The powder is reddish brown. The fibers are mostly in bundles, and the surrounding parenchyma cells contain calcium oxalate crystals, forming crystal sheath fibers. . Cork cells are polygonal and contain reddish brown substances.
(3) Take 2G of the product powder, add 40ml of water, sonicate for 1 hour, cool it, centrifuge, take the supernatant, shake it with ethyl acetate for three times, 25ml each time, combine the ethyl acetate solution, evaporate to dryness, add 2ml of methanol to dissolve the residue, and use it as the test solution. In addition, 2G of Melia azedarach peel reference medicinal material was taken and prepared into the reference medicinal material solution by the same method. Then take the catechin control sample and add methanol to make a solution containing 1mg per 1ml as the control solution. . In the chromatogram of the test sample, spots with the same color appear at the corresponding positions of the chromatogram of the control medicinal material and the chromatogram of the control sample; Spray 10% sulfuric acid ethanol solution and heat it at 105 ℃ until the spots are clear. In the chromatogram of the test sample, spots with the same color appear at the corresponding positions of the chromatogram of the control medicinal material and the chromatogram of the control sample.
[inspection] the moisture content shall not exceed 12.0% (the second method of general rule 0832).
The total ash content shall not exceed 10.0% (general rule 2302).
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; The mobile phase was acetonitrile-0.01% formic acid solution (31:69); A single-stage quadrupole mass spectrometer was used to detect ions with a mass to charge ratio (m/z) of 573 in electrospray ionization (ESI) negative ion mode. The number of theoretical plates shall not be less than 8000 according to toosendanin peak.
Preparation of reference solution take an appropriate amount of toosendanin reference, weigh accurately, and add methanol to make a solution containing 1 μ g per 1ml. Ready to get.
Prepare the test solution, take about 0.25g of the powder (passing through No. 4 screen), weigh it accurately, place it in a round bottomed flask, add 50ml of methanol precisely, weigh it, heat and reflux for 1 hour, cool it, weigh it again, make up the lost weight with methanol, shake it well, filter it, and take the filtrate.
The determination method is to precisely aspirate 2 μ l of the reference solution and 1 ～ 2 μ l of the test solution, inject them into a liquid chromatography-mass spectrometer, and determine them. It is obtained by calculating the sum of the two peak areas of toosendanin.
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Decoction pieces
[processing] remove impurities and coarse skin, wash, moisten, shred and dry.
The product is in irregular filamentous shape. The outer surface is grayish brown or grayish brown, and it is light yellow after removing the coarse skin. The inner surface is off white or light yellow. The cut surface is fibrous, slightly laminated, and easy to peel off. The breath is slight and the taste is bitter.
[identification], [inspection], [content determination] are the same as those of medicinal materials.
[nature, taste and meridian tropism] bitter, cold; . .
[functions and indications] it can kill insects and cure ringworm. For ascariasis, pinworm disease, vermicularis, abdominal pain; External treatment for scabies and itching.
[usage and dosage] 3 ～ 6G. Apply an appropriate amount externally, grind it into powder, and apply pig fat to the affected area.
[note] pregnant women and those with liver and kidney dysfunction should use it with caution.
[storage] store in a ventilated and dry place to prevent moisture.


2、 Chemical constituents of Melia azedarach peel

1. palm bark containsToosendanin（toosendanin）， Melianol, methylkulonate, 7a-acetoxy-l4 β, 15 β - epoxy-gedunan-1-ene-3-o - β - dglucopyranoside, 1,8-dihydroxy-2-methylanthraquinone-3-o - β - d-pyranoside galactopyranoside (1,8-dihydroxy-2-methylanthraquinone-3-o - β - D-galactopyranoside), 1, 5-dihydroxy-8-metho-xy-2-methylanthraquinone-3-o-a-l-rhamnopyranoside, 4 ', 5-dihydroxyflavone-7-o-a-l-rhamnopyranosyl - (1 → 4) - β - d-glucopyranoside ucopyranoside], isotoosendanin. have otherβ - sitosterol（β-sitosterol）， N-tridecane and water soluble components. . The roots of camphor tree contain apigenin-5-o - β - D-galactopyranoside.
2. toosendan bark containsToosendaninThe content of toosendanin in root bark is slightly higher than that in bark.

3、 Pharmacological effects of Melia azedarach peel

1. anthelmintic effect: according to the pig test, the decoction or alcohol extract of this medicine can inhibit or even paralyze Ascaris lumbricoides. Toosendanin is the effective component of Ascaris driving effect, which is stronger than ethanol extract. Toosendanin at a low concentration (1:5000-9000) has an obvious excitatory effect on the whole Ascaris lumbricoides and its segments (head and middle), which is manifested by enhanced spontaneous activity, intermittent abnormal sharp contraction, breaking the regularity of its movement (activity enhancement and attenuation alternate), lasting for 10-24 hours, and finally gradually turning into spastic contraction. . The excitatory effect of toosendanin at this concentration on the nerve muscle of Ascaris lumbricoides was not blocked by atropine, suggesting that toosendanin is not a cholinergic drug. Toosendanin at high concentration (1:1000) has a paralytic effect on Ascaris lumbricoides, especially on the ganglion of the head. This paralytic effect may be the result of intermittent spasm and contraction of the insect body after the drug action. The cholinesterase activity and respiratory fermentation of the worm homogenate were measured by Ammon method and Warner respirator, respectively. The results showed that there was no obvious effect, indicating that toosendanin did not act through glucose metabolism. . The high concentration of Melia azedarach peel (25% - 50%) also has a paralytic effect on pinworm in mice in vitro.

2. effects on respiratory center: a large dose of toosendanin (2mg intravenously or intramuscularly for each rat) can cause respiratory failure in rats. This is mainly due to the inhibitory effect of this component on the central nervous system. The above results were supported by the direct administration of toosendanin (0.10-0.15mg per rat) to the respiratory center of the medulla oblongata. Nikethamide, a central stimulant, had a slight antagonistic effect on the respiratory depression induced by toosendanin.

3. effects on neuromuscular transmission function: toosendanin can irreversibly inhibit muscle contraction caused by indirect stimulation in rats, but it does not affect nerve excitation conduction, nor reduce muscle response to direct stimulation; Toosendanin is a neuromuscular transmission blocker that selectively acts on presynaptic sites. Its action site is at presynaptic nerve terminals, and its mode of action is to inhibit acetylcholine release induced by nerve stimulation. Electron microscopic observation showed that toosendanin had an obvious effect on the submicroscopic structure of neuromuscular junction in mice, which was manifested in the increase of synaptic gap width and the decrease of synaptic vesicle number. These two changes do not occur in the same joint at the same time.

4. anti botulism: toosendanin has a therapeutic effect on botulism animals. For mice with lethal dose of botulism type A, toosendanin given 6 hours after poisoning has obvious therapeutic effect; For monkeys with lethal dose of botulism type A, toosendanin given 24 hours after poisoning can cure more than half of the animals; Toosendanin also has a protective effect on mice with type B botulism. .

5. effects on the electromyography and mechanical properties of the cardiac papilla: Azadirachtin concentration dependently prolongs the time course of repolarization of the fast response potential to 90% (APD 90). Blocking IK1 with barium chloride can cancel the effect of toosendanin on prolonging apd90. Toosendanin can prolong the slow response electric field PD and enhance the contractility (FC). After using barium chloride, the above effect of toosendanin can be canceled, but the effect of prolonging APD exists. In addition, toosendanin can make the isolated frog heart systolic rhythm abnormal, and it can automatically recover for 1 hour.

. Toosendanin at a concentration of 0.2 × l0 (-3) mg could induce spastic contraction of intestinal muscles. This excitatory effect could be antagonized by diphenhydramine, but not blocked by atropine. The 10% aqueous extract of Melia azedarach peel has inhibitory effect on a variety of pathogenic fungi. Melia azedarach root bark extract has certain curative effect in the treatment of experimental schistosomiasis mansoni in mice, which has been confirmed from the number of live worms in animals and hatching test.