Apocynum venetum leaves
1、       This product is the dried leaves of Apocynum venetum L., a plant of Apocynaceae. Harvest in summer, remove impurities and dry.
      [properties] this product is mostly wrinkled and curled, some are broken, and the complete leaves are oval lanceolate or oval lanceolate after flattening, with a length of 2-5cm and a width of 0.5-2cm. It is light green or grayish green, blunt at the apex, with a small awn tip, blunt round or wedge-shaped at the base, with fine teeth at the edge, often reflexed, hairless on both sides, and the leaf veins protrude on the lower surface; . The air is weak and the taste is light.
      [identification] (1) the appearance of this product: the upper and lower epidermal cells are polygonal, the vertical walls are flat and straight, and the surface has granular keratin texture; Air hole horizontal shaft type.
      Cross section of this product: the epidermal cells are flat and the outer wall is protruding. There are palisade tissues on both sides of the leaf. There are two rows of palisade cells in the upper epidermis and one row in the lower epidermis. The cells are very short, and there are two to four rows of sponge tissue cells, containing brown matter. The vascular bundle of the main vein is double tough, and there are milk tubes scattered around the vascular bundle and phloem.
      (2) Take 1g of the product powder, add 50ml of ether, heat and reflux for 1 hour, cool it, filter it, discard the ether solution, add 25ml of water to the drug residue, heat and reflux for 1 hour, cool it, filter it, shake and extract the filtrate with ethyl acetate twice, 20ml each time, combine the ethyl acetate solution, evaporate it to dryness, add 1ml of methanol to dissolve the residue, and use it as the test solution. Another 1g of Apocynum venetum leaf reference drug was taken and prepared into the reference drug solution by the same method. According to the test of thin-layer chromatography (general rule 0502), suck 3 µ l of each of the above two solutions, dot them on the same silica gel G thin-layer plate respectively, use the lower layer solution of chloroform methanol water (13:7:2) placed overnight below 10 ℃ as the developing agent, develop, take out, dry, spray with 3% aluminum trichloride ethanol solution, heat at 105 ℃ until the spots are clear, and inspect under the ultraviolet light (365nm). In the chromatogram of the test sample, fluorescent spots of the same color appear at the position corresponding to the chromatogram of the control medicinal material.
      (3) . In addition, take quercetin reference substance and kaempferol reference substance and add ethanol to make a solution containing 0.5mg per 1ml respectively as the reference solution. According to the thin-layer chromatography (general rule 0502), suck 5 µ l of the test solution and 2 µ l of the two control solutions, respectively dot them on the same silica gel G thin-layer plate, use n-hexane ethyl acetate formic acid (7:5:0.8) as the developing agent, develop, take out, air dry, spray with 3% aluminum trichloride ethanol solution, heat at 105 ℃ until the spots are clear, and inspect them under sunlight and ultraviolet light (365nm). In the chromatogram of the test sample, spots or fluorescent spots of the same color appear at the corresponding positions of the chromatogram of the control sample.
      [check] moisture   .
        Total ash   Not more than 12.0% (general rule 2302).
      Acid insoluble ash   .
      [extract] according to the hot leaching method under the alcohol soluble extract determination method (general rule 2201), 75% ethanol shall be used as solvent, which shall not be less than 20.0%.
      [content determination] determine according to HPLC (general rule 0512).
      Chromatographic conditions and system suitability test   Octadecylsilane bonded silica gel was used as filler; The mobile phase was acetonitrile-0.2% phosphoric acid solution (15:85); The detection wavelength was 256nm. The number of theoretical plates should not be less than 6000 according to hyperin peak.
      Preparation of reference solution   Take an appropriate amount of hyperin reference substance, weigh it accurately, add methanol to make a solution containing 36 µ g per 1ml.
      Preparation of test solution   Take about 0.5g of this product powder (passing through No. 3 screen), weigh accurately, place it in a corked conical flask, add 50ml of 50% methanol precisely, close the stopper, weigh, heat and reflux for 30 minutes, cool, weigh again, make up the lost weight with 50% methanol, shake well, filter, and take the filtrate.
      ; Precisely suck l0 µ l of the reference solution and l0 µ l of the test solution respectively, inject them into the liquid chromatograph, and determine.
      According to the calculation of dry product, the content of Hyperoside (c21h20o12) shall not be less than 0.30%.
      . .
      [functions and indications] it can calm the liver, calm the nerves, clear away heat and promote diuresis. .
      .
      [storage] store in a cool and dry place.


2、
Leaves contain quercetin （quercetin），Isoquercitrin（iso-quercitrin），Hyperin（hyperoside），rutin（rutin），Catechin（catechin）， Anthraquinone, glutamic acid,L-alanine（alanine），L-valine (valine) and other amino acids, nonacosane, 1-TRIACONTANOL, hentriacontane, lupenyl palmitate, myricylpalmitate, hexadecyl palmitate, meso inositol,β - sitosterol（β-sitosterol）， Potassium chloride, tannins and polysaccharides,Lupeol（lupeol）， Isofraxidin andScopoletin Pavilion(scopoletin) et al. The root contains cymarin, k-stro-phanthin - β andHelianthin（strophanthidin）。

3、 Pharmacological effects of Apocynum venetum leaves
1. Hypotensive effect

The blood pressure of Apocynum venetum leaf Decoction decreased from 194 / 142mm Hg to 152 / 100mm Hg 2 hours after gavage in dogs with renal hypertension, and remained stable at a low level until it rebounded 3 days later.

2. Cardiotonic action

Apocynin contained in the root of Apocynum venetum can increase the contraction amplitude of isolated and eutopic cat hearts, slow down the heart rate, then arrhythmia, and finally stop the heart beat in systole. Its nature and speed of action are similar to that of strobiloside. Central inhibitors such as sodium pentobarbital can weaken its cardiotonic effect. The extract of Apocynum venetum root also showed cardiac glycoside like effect on eutopic cat heart. The efficacy of the same genus of plants (such as Apocynum cannabium) for patients with atrial fibrillation is worse than that of digitalis. If used at a dose sufficient to control cardiac arrhythmia, it often causes nausea, vomiting and diarrhea.

3. Effects on experimental heart disease

Canavanoside has a therapeutic effect on experimental cardiovascular insufficiency in dogs, alleviates the symptoms of acute circulatory dysfunction of myocarditis in rabbits, and prevents myocardial and coronary vascular sclerosis. This effect is superior to that of strobiloside. It can restore the ECG changes of atherosclerotic rabbits to normal, and the contraction effect on coronary artery is particularly significant. It also has curative effect on atherosclerosis caused by hypophysin and thrombin in rabbits with coronary circulation insufficiency, but it is weak. Can increase cardiac glycogen resynthesis.

It has no effect on hyperlipidemia in mice fed with high-fat diet; These results indicate that Apocynum venetum leaves can reduce the increase of endogenous blood lipids.

4. Radiation resistance

Apocynum venetum leaf extract 2g/kg gavage and 0.5g/kg intraperitoneal injection for 15-20 consecutive days can prolong the survival days of 60Co γ - ray irradiated mice, increase the survival rate, and increase the number of white blood cells in the blood. Quercetin 30mg/kg gavage also has the same effect. It is believed that the anti radiation effect of Apocynum venetum leaf is related to quercetin.

5. Effect on spleen

Triacontanol had no significant effect on the growth of normal young rats; It can increase the weight of mouse spleen, especially 20mg/kg intramuscular injection; The effect on thymus of adult rats was slightly increased, while that of young rats was slightly reduced; It has obvious antagonism to the weight loss of spleen and thymus caused by cyclophosphamide; .

6. Effect on cardiovascular system

The water filtrate of Apocynum venetum extract (10%) was injected into anesthetized dogs at a constant rate (2.0ml/kg, 3.6ml/min), and the blood pressure decreased. . At the same time, the blood pressure decreased and the cardiac output, cardiac index, cardiac stroke index and left circumflex coronary artery blood flow decreased. It has no effect on the pre and post cardiac load. Intramuscular oxygen consumption decreased 3 minutes after i.v. Dogs were intravenously injected with Apocynum venetum leaf Decoction (0.25g/kg) or its flavonoid glycosides (10-15mg/kg). After 1-10 minutes, the heart rate significantly slowed down and recovered after 30 minutes. When the dosage of the decoction increased to 1g/kg and the flavonoid glycosides increased to 20mg/kg, arrhythmias, ST segment depression, and T-wave deformation could occur, indicating that both can cause cardiotoxic reactions. ; The hypotensive effect of one dose of Apocynum venetum leaves decoction was maintained for 3-10 minutes, but it had rapid tolerance. When Apocynum venetum leaves Decoction (1.5.10g/kg) was administered to experimental renal hypertensive dogs, blood pressure decreased when 5g/kg appeared. It decreased from 194 / 142 to 152 / 100mmhg after 2 hours of administration, and then recovered after 3 days. Flavonoid glycosides can significantly dilate the blood vessels of isolated rabbit ears when perfused with 5mg each time.

7. Diuretic effect

The water extract of Apocynum venetum leaves and the burning residue of the extract have diuretic effect. The total urine output of rats at 6-24 hours and 24 hours after oral administration of the water extract of Apocynum venetum leaves increased by 50.60% and 32.28%, respectively. At the same time, the urine sodium and potassium output also increased correspondingly, but there was no significant difference in urine potassium and sodium concentrations between the administration group and the control group. After intravenous injection of Apocynum venetum leaf water extract for 30 minutes, the urine output increased significantly (the urine output increased by 28.96-106.20%), and the effect lasted for more than 2 hours, while the urine sodium and potassium output did not increase significantly (the urine potassium output only increased within 2 hours), and the urine sodium and potassium concentrations were lower than those before administration. After intravenous injection of Apocynum venetum leaf aqueous extract, the urine volume of dogs at each phase within 60 minutes increased significantly, and the excretion of sodium and potassium in urine also increased correspondingly, but the concentrations of sodium and potassium in urine were lower than those before administration. The burning residue of Apocynum venetum leaf extract has a rapid and strong diuretic effect on rabbits, but the duration of action is shorter than that of the extract.

8. Hypolipidemic effect

Apocynum venetum leaf water extract can significantly reduce the serum total cholesterol value and triglyceride value of rats with hyperlipidemia caused by Triton, but failed to reduce the cholesterol value of mice with hypercholesterolemia caused by high-fat diet.

9. Anti aging effect

Apocynum venetum leaf extract can delay aging or prolong life span of Drosophila, silkworm and mice. Apocynum venetum leaf extract can reduce the content of visceral lipofuscin in mice to varying degrees, and can generally increase the activity of superoxide dismutase (SOD) in the liver and heart of mice in different age groups. Apocynum venetum tea can increase the sod value and hdl-e in erythrocytes, which may be beneficial to prevent arteriosclerosis.

10. Other functions

After intraperitoneal injection of 0.5g/kg Apocynum venetum leaf extract into mice for 30 minutes, the spontaneous activity of mice was significantly reduced, and the effect lasted for more than 5 hours. It also had a synergistic effect on the sedative hypnotic effect of pentobarbital, and had a certain anticonvulsant effect. At the concentration of 1:1000, Apocynum venetum leaf decoction had no obvious effect on the contraction amplitude and frequency of isolated rat uterine smooth muscle. At 1:2000, it could significantly reduce the contraction amplitude and frequency of isolated rabbit intestinal muscle and rat uterus.