1、 Pharmacopoeia standard of Piper longum
This product is a dry, nearly mature or mature fruit spike of Piper longum L., a pepper plant. When the ears turn from green to black, they are harvested, impurities are removed, and dried in the sun.
[character] this product is cylindrical, slightly curved, and is composed of many small berries, 1.5 ~ 3.5cm long and 0.3 ~ 0.5cm in diameter. The surface is dark brown or brown, with small protrusions arranged in an oblique direction, and the base has residual or fallen fruit stalk. It is hard and brittle, easy to break, with irregular section and granular shape. Small berries are spherical, about 0.1cm in diameter. They have a special aroma and spicy taste.
[identification] (1) the powder of this product is grayish brown. The stone cells are round, long oval or polygonal, with a diameter of 25-61 μ m and a length of 170 μ M. the wall is thick, and some of them have obvious laminar lines. The oil cells are round in shape with a diameter of 25 ～ 66 μ M. The endocarp cells are long polygonal on the surface, with irregular bead like thickening of the pericarp wall, which is often connected with brown seed coat cells. The seed coat cells are reddish brown and appear long polygonal on the surface. Starch grains are fine and often agglomerate.
(2) Take a small amount of this product powder and add a drop of sulfuric acid to make it bright red, gradually reddish brown, and then turn brown.
(3) Take 0.8g of this product powder, add 5ml of absolute ethanol, sonicate for 30 minutes, filter, and take the filtrate as the test solution. Take another piperine reference substance, put it into a brown volumetric flask, add absolute ethanol to make a solution containing 4mg per 1ml as the reference solution. According to the thin-layer chromatography (general rule 0502), suck 2 μ l of each of the above two solutions, dot them on the same silica gel G thin-layer plate, use toluene ethyl acetate acetone (7:2:1) as the developing agent, develop, take out, dry, and view under the UV light (365nm). ; Spray with 10% sulfuric acid ethanol solution, heat until the spots are clear, and the same brown yellow spots appear at the corresponding position of the reference substance chromatography.
[inspection] impurities shall not exceed 3% (general rule 2301).
The moisture content shall not exceed 11.0% (the fourth method of general rule 0832).
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[content determination] determine according to high performance liquid chromatography (general rule 0512).
Chromatographic conditions and system suitability test octadecylsilane bonded silica gel was used as filler; ; The detection wavelength is 343nm. The number of theoretical plates should not be less than 1500 according to the piperine peak.
Preparation of reference solution take an appropriate amount of piperine reference, weigh it accurately, place it in a brown volumetric flask, add absolute ethanol to make a solution containing 20 μ g per 1ml.
Preparation of test solution take about 0.1g of powder in this product, weigh accurately, put it into a 50ml Brown volumetric flask, add 40ml of absolute ethanol, sonicate (power 250W, frequency 20KHz) for 30 minutes, cool it, add absolute ethanol to the scale, shake well, filter, accurately measure 10ml of continuous filtrate, put it into a 25ml Brown volumetric flask, add absolute ethanol to the scale, shake well, filter, and take the continuous filtrate.
The determination method is to precisely suck 10 μ l of the reference solution and 10 μ l of the test solution, inject them into the liquid chromatograph, and determine.
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Decoction pieces
[processing] remove impurities. Mash when needed.
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[nature, taste and meridian tropism] pungent, hot. Return to stomach and large intestine.
[functions and indications] it can dissipate cold in the middle of temperature and relieve pain by lowering Qi. For epigastric cold pain, vomiting, diarrhea, cold coagulation and qi stagnation, chest pain, headache, toothache.
[usage and dosage] 1 ～ 3G. Apply appropriate amount externally, and put it into the carious teeth at the end of grinding.
[storage] store in a cool and dry place to prevent moths.

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Piper longum fruit containsPiperine，palmitic acid, tetrahydropyranic acid, undec-1-ene-3,4-methylenedioxy benzene, piperidine, volatile oil, n-isobutyl decadiene-trans-2-trans-4-amide,Sesamin. The seeds contain piperine and bisisoeucalyptus.

3、 Pharmacological effects of Piper longum

1. antibacterial effect: the volatile oil contained in this product has inhibitory effect on Staphylococcus aureus, Bacillus subtilis, Bacillus cereus, Mycobacterium tuberculosis, Shigella dysenteriae, Salmonella typhi T and B, octella ovale and influenza virus.

2. effect on central nervous system:

2.1. anticonvulsant effect: 150mg/kg intraperitoneal injection in rats has obvious anticonvulsant effect of pentylenetetrazole, which significantly reduces the convulsion rate, and also has obvious antagonistic effect on electric convulsion and audiogenic seizures. The intensity of anticonvulsant effect can be compared with that of phenytoin sodium and trimethylenedione.

. It has a synergistic effect with thiopental sodium and has an inhibitory effect on the respiration of morphine pentobarbital, which is stronger and safer than pentylenetetrazole or Nikethamide.

2.3. effects on cholesterol metabolism in mice: Piper longum oil unsaponifiable 40mg/kg, administered by gavage for 20 days, significantly reduced exogenous hypercholesterolemia induced by feeding a diet containing 2% cholesterol.

3. impact on cardiovascular system:

3.1. effects on myocardial camp blood flow in mice: mice were injected intraperitoneally with different concentrations of Piper longum preparation. After 30 minutes, according to the nutritional blood flow measurement method, the uptake ability of 86Rb in mouse myocardium was observed. The experimental results showed that with the increase of drug concentration, the myocardial uptake ability of 86Rb gradually decreased. . When the drug concentration increased to 13.3g/kg, the lowest value appeared, and the myocardial uptake of 86Rb in mice decreased by 8.0 ± 4.10% (p< 0.01) at this dose, which was equivalent to b-blocker. However, when the drug dose was increased to 17.8g/kg, contrary to the above results, it could increase the myocardial uptake rate of mice to 9.5 ± 3.68% (p< 0.01). The effect of this dose was equivalent to that of B-receptor agonist, which could increase coronary blood flow and improve myocardial metabolism to a certain extent. Therefore, Piper longum can be used as B-receptor blocker and B-receptor agonist at different doses. Therefore, the clinical dosage needs to be strictly controlled.

3.2. effects on hypoxia tolerance and anti acute myocardial ischemia: the volatile oil of Piper longum can improve the hypoxia tolerance of mice under decompression conditions. The survival rate of the drug group was 93.1% and that of the control group was 18.6%. The atmospheric hypoxia tolerance test showed that the volatile oil of Piper longum could prolong the survival time of mice by 37.8%; The survival time of mice with increased oxygen consumption caused by isoproterenol could be increased by 30% compared with the control group. The survival time of hypoxia mice induced by sodium nitrite can be increased by 64%. . The volatile oil of Piper longum also significantly antagonized the T-wave changes and heart rate slowing effects in rabbits caused by pituitrin.

3.3. coronary vasodilation: dehydropipernonaline contained in Piper longum can inhibit the contraction of isolated rabbit coronary arteries caused by KCl 40mm in a concentration dependent manner. It can completely resist the contraction caused by KCl at a concentration of 10-5m.

. 20. The effect of 30 and 40mg/kg non saponified substance on reducing TC increased with the increase of dose. 40mg/kg dose can significantly increase the serum lecithin cholesterol acyltransferase (LCAT) activity of mice injected with Egg Yolk Emulsion intraperitoneally. The results showed that the unsaponifiable matter of Piper longum oil could reduce blood lipid and inhibit the formation and development of as, which was related to its promotion of cholesterol esterification and excretion.

3.5 the unsaponifiable matter of Piper longum oil can also significantly reduce the content of serum total cholesterol and liver cholesterol in mice with endogenous hypercholesterolemia induced by feeding 5% lard feed, and significantly inhibit the increase of serum total cholesterol induced by Triton in mice.

. It can inhibit the tension and contractility of rabbit and rat ileum.