Tieshuguo

Tieshuguo

(a textual research on the names and facts of plants)

[synonym] Fenghuang egg.

[source] it is the seed of Cycadaceae. For plant morphology, please refer to "Fengwei banana leaf".

[chemical constituents] the cones (including seeds) contain 0.086% of threoniflorin (about 0.2-0.3% of seeds), a, B, C, D, e, F, g of neothreoniflorin, a large amount of free palmitic acid (6.95% of exotesta), a large amount of starch, β - carotene, cryptoflavin, zeaxanthin and other pigments.

(1) carcinogenesis

Since it was found in 1962 that the liver and kidney tumors could be produced by feeding rats with the mixture of threoniflorin in food, threoniflorin has been synthesized as a carcinogen. It is generally believed that it is similar to dimethylnitrosamine, which can be metabolized into diazomethane in vivo and has carcinogenic effect on a variety of cells. The results show that the function of cycadoside can only be achieved after it is decomposed into cycadosigenin by enzymes or bacteria in the intestine; the cancer can only be caused by oral administration of cycadoside, but not by injection (the decomposing enzyme also exists in the subcutaneous tissue of newborn rats, at this time, it can also cause cancer by subcutaneous injection, and the enzyme disappears at 3-4 weeks after birth). However, oral administration and injection of cygenin were effective. A single dose of cygenin was enough to make most rats produce tumor. The rats fed for a short time were prone to kidney tumor, while the rats fed for a long time were prone to liver tumor. Immature young rats are prone to renal true tumor, renal sarcoma and renal stromal tumor, while renal adenoma is not related to maturity. The occurrence of tumor is always 6 months after the administration of threoniflorin (even if there is intrafetal contact, it must be 6 months after the occurrence of tumor). The carcinogenic rate of cygenin in rats was 100%, while that of cygenin was 85%, which was not related to the species of rats. In addition to rats, it can also cause cancer in mice, guinea pigs and golden hamsters. Cygenin can produce all kinds of tumors caused by cygenin, such as duodenal tumors caused by intraperitoneal injection. The resulting tumor can be transplanted. The morphology of renal adenoma in rats is similar to that in human or other animals, which is caused by direct action on renal tubular epithelial cells.

② Neurotoxicity

When cattle eat the seeds of tieshuguo, they can cause paralysis and often have amyotrophic lateral sclerosis of spinal cord; the thin bundle and dorsal spinal cerebellar tract produce demyelination and osmiophilic substance deposition. In the central nervous system of rats, no abnormal lesions were found. If the fetus of rat or golden field rat is exposed to cygenin in the mother, it can cause obvious malformation of the central nervous system, prevent its normal development (mainly the two hemispheres of the brain) and form "microcephaly". The bony cranial tectum becomes narrower, but the survival time is still quite long. Some rats have glioma after 13-15 months.

The mechanism of toxicity has not been fully elucidated. The most obvious pathological changes were found in the liver. The degree of the lesion is related to the dose. In mild cases, the basophil and glycogen in the cytoplasm are lost, and the glucose-6-phosphatase is reduced. In severe cases, there are extensive hemorrhage and necrosis of the central lobule, the decrease of liver ribonucleic acid and total phospholipid, and the decrease of liver protein synthesis. In mouse liver, the incorporation of h3-dioxin into RNA and C14-thymidine into DNA are inhibited. Protein synthesis in kidney, spleen and small intestine was not affected. Cycadoside and its aglycone have alkylation in vivo and in vitro. In the experiments of Drosophila melanogaster and Salmonella typhi, it was also found that cygenin was a powerful mutagen. It is similar to mitomycin C and nitrogen mustard, and has antitumor effect. The toxicity of cyroside to cold-blooded animals is very small. After 12-18 hours, the mice were found to have dyspnea and finally died of paralysis. The median lethal dose was 1.67 mg / g. 0 g / kg. In postmortem anatomy, the main pathological changes were blood stasis and bleeding. Threoniflorin has little effect on respiration, blood pressure, heart, blood vessel, intestine or uterus.

[flavor] bitter and astringent, flat. Toxic.

① Modern practical Chinese medicine: "bitter, smooth, sour, non-toxic. "

② Lu Chuan's materia medica: "it's mild in taste and cold in nature. "

[functions and indications] ① modern practical Chinese medicine: "it is a astringent, dredging meridians, helping digestion, antitussive and expectorant. The starch in the fruit can cure dysentery and hiccup. "

② "Lu Chuan Materia Medica": "anti inflammation, hemostasis. It can cure phlegm, cough, dysentery, knife wound and contusion. "

[usage and dosage] oral administration: decoct soup, 3-5 yuan; or grind powder. External use: apply at the end of the research.

Chinese PinYin : Tie Shu Guo