Cassia seed, the traditional Chinese medicine name, is the dried and mature seed of the leguminous plant Cassia or small Cassia, which is known for its ability to improve eyesight. Ripe fruits are harvested in the autumn, dried, seeds are laid, and impurities are removed. Traditional Chinese medicine believes that cassia seed cold, taste sweet, bitter, return to the liver, large intestine, with "clearing heat, brighting the eyes, moistening the bowel" and other effects, for the eyes red astringent pain, shame more tears, headache vertigo, dark eyes unknown.

The chemical composition, pharmacological action and clinical application of Cassia seed were reviewed in this paper.

Ancient books record: "Shennong Herbal Classics" : "the main green blind, eyes and skin, red and white film, eyes red pain tears."

"Mongolian Materia Medica" : "Remove liver heat especially and liver Qi, collect eyes tears and stop eye pain."

Essentials of Materia Medica: "Purging liver and improving eyesight."

 "Compendium of Materia Medica" : "In addition to liver gall wind heat, skin white film, green blindness."

1 Chemical composition of Cassia seed  

The trace metal elements contained in Cassia seed have an impact on human enzyme composition, human oxidation-reduction catalysis, metabolism, central nervous system and blood circulation. The main components and their effects are as follows:

1. Emodin and rhein have anti-asthmatic, gallbladder, liver protection and antihypertensive effects, and have certain antibacterial and anti-inflammatory effects;

2. Emodin allione, emodin glucoside and emodin methyl ether have the effect of lowering serum cholesterol and strengthening heart；

3. Cassia seed has A-hydroxyl group, which can form complex with metal elements, and has influence on the absorption of biological metal elements；

4. Beta-carotene can be converted into vitamin A under the action of human liver enzymes;

5. Emodin dianthrone glycosides have cathartic effect;

Cassia seed is rich in essential trace elements: iron (45ppm), zinc (28.5ppm), manganese (41.37ppm), copper (6.9ppm), nickel (0.27ppm), cobalt (0.09ppm), molybdenum (0.017ppm). Iron is A nutrient element in human body, zinc is involved in enzyme synthesis, and has an effect on the composition of vitamin A reductase in retina, which is related to the synthesis of retinal aldehyde, and has a great impact on vision. Zinc and manganese can treat and prevent atherosclerosis and affect liver metabolism. Cobalt and nickel play an important role in the stability of nucleic acid configuration and properties, as well as the normal replication of DNA.

2 Pharmacological Effects of Cassia seed

2.1 Antihypertensive effects

The aqueous and alcoholic aqueous extract of Cassia seed has antihypertensive effects on anesthetized dogs, cats and rabbits. However, the effect of water infusion on hypotension of anesthetized rabbits was not obvious. Liu Juxiu et al. "Cassia seed injection prepared by water extraction and alcohol precipitation was administered to spontaneously hypertensive rats through femoral vein, and the changes of blood pressure, heart rate and respiration were observed. Results The diastolic blood pressure and systolic blood pressure of rats were decreased significantly, and there was no effect on respiration and heart rate. The experiment proved that the effect was stronger than reserpine and lasted longer. Xu Shibo et al. "Also reported that the fat-soluble part of cassia seed showed a significant antihypertensive effect at 10mg/kg (P< 0.05), alcohol and water soluble parts showed significant antihypertensive effects at 15mg/kg (P< 0.05), and it was also proved that anthraquinone glycosides have obvious cathartic effect, reduce intestinal absorption of cholesterol and increase excretion, regulate low-density lipoprotein metabolism through feedback, thereby reducing serum cholesterol level, and play a role in delaying and inhibiting the formation of atherosclerotic plaque.

2.2 Lipid-lowering Effect

Shen Qigui et al studied the effect of cassia seed on the formation of atherosclerosis with experimental hypercholesterolemia in rabbits. The serum cholesterol level, the extent of aortic wall lesions and the amount of cholesterol deposition were used as observation indexes to prove that cassia seed can reduce serum low density lipoprotein cholesterol and inhibit the formation of atherosclerotic plaque. Chen Weixing et al. "Report. A mouse model of hypercholesterolemia was used to study the effect of cassia seed on cholesterol. The results showed that although cassia seed did not affect the level of serum total cholesterol (TC), it could significantly increase the content of serum high density lipoprotein cholesterol (HDL-C) and increase the ratio of HDL-C/TC, thus significantly improving the distribution of cholesterol in the body, which contributed to the eventual transport of cholesterol to the liver Final treatment is advantageous.

2.3 Improving eyesight

Han Changzhi et al studied the effect of cassia seed on the eyesight of rabbits or dogs, which were divided into the administration group and the control group. The administration group was injected with 50% cassia seed decoction once a day in the morning and in the afternoon at the rate of 2ml/kg, and the control group was injected with the same amount of distilled water for 37 days to kill the animals, and the ciliary muscle was taken to determine the activity of lactate dehydrogenase (LDH). The results showed that the activity of LDH was significantly higher than that of control group (P< 0.01), and correspondingly increase the content of adenosine triphosphate (ATP) in eye tissue, indicating that cassia seed has the function of activating LDH in eye tissue, so as to prevent myopia and achieve the role of eyesight. In addition, the rich trace elements zinc and vitamin A contained in cassia seed may also be related to the effect of eyesight.

2.4 Effects on immune function of mice

Three groups of mice were injected with cassia seed aqueous alcohol solution of 5mg/kg, cyclophosphamide of 10mg/kg and normal saline of 0.2ml as control,bid, continuously for 7 days to observe the effect on immune function. The results showed that the thymus of mice was atrophied and the structure was changed obviously (P<0.05), and the phagocytic percentage and phagocytic index of mice were increased significantly (P<0.01). However, the formation of serum hemolysin was not significantly different between the control group and the water extract of alcohol sedimentation (P>0.05). In conclusion, cassia seed can inhibit the immune function of mice and enhance the phagocytosis function of macrophages, but has no obvious effect on humoral immune function.

2.5 Bacteriostatic effect

The aqueous alcohols of cassia seed can inhibit most skin fungi and bacteria. After alcohol removal, the ethanol extract of cassia seed had an inhibitory effect on Staphylococcus aureus, Staphylococcus albus, Staphylococcus orange, Bacillus giant, Bacillus typhoid, Bacillus paratyphoid, Bacillus paratyphoid B and Escherichia coli, but the water extract had no effect. In addition, the deoxymacrotin contained in cassia seed has an inhibitory effect on trichophyton rubrum and Trichophyton palpis, microspora cyanides and Candida albicans."

2.6 Catharsis

Shen Qigui et al. found that cassia seed could enhance intestinal peristalsis at 6.9g/kg, but little cassia had no obvious effect. At 13.8g/kg, both kinds of cassia can increase the frequency of defecation, and the anthraquinone glycosides of cassia have obvious cathartic effect.

2.7 Liver protection and anti-platelet aggregation

Chrysophanol contained in cassia seed has liver protection, while naphthalene and pyranone have anti-hepatitis virus effects. The glucoside amblyophyll in cassia can strongly inhibit platelet aggregation caused by adenosine diphosphate, arachidonic acid and collagenase.

3 Clinical application of cassia seed

3.1 Treatment of hypertension

Zhou Ran et al. "17 patients with hypertension took cassia seed tea (soaked cassia seed with boiling water as tea), 2-3 bags/day,4wk for 1 course of treatment. Results The systolic blood pressure and diastolic blood pressure were significantly reduced. According to the therapeutic criteria for hypertension, there were 6 cases of obvious effect, 6 cases of effective and 5 cases of ineffective treatment.

3.2 Treatment of hypercholesterolemia

Hu Kangcai et al. treated 29 cases of hyperlipidemia with cassia seed tea, more than 10g/d, divided into two tea drinks in the afternoon. After taking 1 to 2 courses of treatment, the serum TC and triglyceride content can be significantly reduced, but the latter does not fall to the normal level, while the HDL-C content is significantly increased, and the ratio of serum TC to HDL-C is increased, close to the normal level. Wang Jing treated 24 cases of hypercholesterolemia with cassia seeds 20~30g/d and offspring tea (not less than 500ml) with open water, and the average TC decreased by 19.2% after 1 month (P<0.05). The mean decrease was 27.4% after treatment 1a (P<0.01). The average decrease after treatment 2a was 27.1%(P<0.01).

3.3 Treatment of constipation

Zhang Wenqing "cassia seed pill 30g/d to treat 200 cases of constipation, take 1~2d, can defecate, no abdominal pain, diarrhea and other side effects,5d for a course of treatment, the total effective rate of 96%."

3.4 It is used for improving eyesight and relieving swelling in ophthalmology

The activity of LDH in aqueous humor and serum of senile cataract patients is lower than that of normal people. After taking cassia, the activity of LDH in eye tissue is increased, so as to maintain the normal level of LDH in eye tissue and prevent and delay the occurrence and development of senile cataract.

3.5 For the treatment of early mastitis

Liu Changhai treated early mammary carbuncle with cassia seed. Depending on Mingzi 25~100g, according to the severity of the disease of mastitis patients, the strength of the physique to increase or decrease the amount of medicine, water decoction, generally 1~3 doses will be cured. Liu Minyuan et al. " Single flavor cassia seed was used to treat gynecomastia,25~30g/d, brewed with boiling water to substitute tea, or pressed into powder,25g/ d, bid, and swallowed with boiling water. 12 cases were cured, followed up by 1~2a, no recurrence. In addition, due to the bitter cold of cassia seed heat, swelling and poison, can also be used for heat toxic sore carbuncle, oral ulcer and infantile malnutrition.

3.6 Reduce canker ulcer

In the treatment of patients with oral ulcers, an appropriate amount of cassia seed powder was sprinkled on the ulcerated surface 4 times a day, or with cassia seed decoction and gargle, the ulcerated surface healed in 5 to 10 days, and the course of all types of ulcers was shortened in different time, and the clinical pain symptoms were alleviated to varying degrees. The effect was significant for oral ulcers caused by vigorous liver fire.

[Toxicity and side effects] 16%-32% cassia seed was added into the rat feed, and with the increase of cassia seed dose, the weight of rats also increased, and the amount of feed and drinking water decreased. When the amount of cassia seed added to the diet was less than 8%, the sperm in the testis of rats was reduced, the bone marrow was reduced, the number of polychromatic red blood cells in the bone marrow was reduced, and the ratio of neutrophil to lymphocyte was increased.