Views: 16 Author: Site Editor Publish Time: 2022-08-04 Origin: Site
Shiitake polysaccharide (Lentinan, LNT) is an active ingredient extracted from the fruiting body of high-quality shiitake mushrooms, the main ingredient of shiitake mushrooms is polysaccharides and unsaturated fatty acids, but also contains a large number of ergosterols and bacteriosterols that can be converted into vitamin D, and the polysaccharides of shiitake mushrooms extracted by hot water can regulate the activity of T cells with immune function in humans, which can reduce the ability of methyl gall anthracene to induce tumors. Shiitake mushrooms have a strong inhibitory effect on cancer cells, with an inhibition rate of 97.5% on mouse sarcoma 180 and an inhibition rate of 80% on Ai's carcinoma. Shiitake polysaccharides also have a strong inhibitory effect on various bacteria, viruses and parasites. The antitumor effect of shiitake polysaccharides involves the regulation of immune or vascular function. Shiitake mushrooms contain double-stranded RNA, which induces the production of interferons and has antiviral properties.
Fungal polysaccharides as a drug began in the 1950s, after the 1960s to become an immune promoter has received widespread attention, in 1969, the world's authoritative scientific journal "Nature" for the first time published an article to expound the anti-tumor effect of shiitake mushroom polysaccharides, causing the scientific community to pay attention to polysaccharides.
In 1969, Japan's Chihara Wulang first used hot water to extract 6 kinds of extracellular polysaccharides from the fruiting body of shiitake mushrooms, of which 2 have obvious anti-tumor activity, and their average relative molecular mass is 1,000,000, which belongs to the branched β (1→3) dextran. In 1970, Chihard et al. extracted 4 other polysaccharides from shiitake mushrooms with hot water extraction combined with organic solvent precipitation, of which 2 polysaccharides had antitumor effects.
In the early 1970s, Shida et al. extracted three water-soluble polysaccharides from shiitake mushrooms by means of trichloroacetic acid extraction and methanol precipitation, one of which was composed of Gal, L-Fuc and Man (molar ratio 6:1.5:1), which was the first anti-tumor substance reported in shiitake mushrooms in addition to β-dextran. Sasaki also reported that in addition to the macromolecular shiitake polysaccharide with a relative molecular mass of 1 million, another small molecule with a relative molecular mass of 16,000 shiitake polysaccharides also has anti-tumor activity.
In 1980, Japanese goji ii confirmed that shiitake polysaccharides are a broad-spectrum immune booster. Subsequent large numbers of studies have shown that shiitake polysaccharides have anti-tumor effects, especially for chronic myelogenous leukemia, gastric cancer, nasopharyngeal cancer, rectal cancer and breast cancer, etc. Have the effect of inhibiting and preventing postoperative micro-metastasis, which is indirect toxicity to cancer cells by enhancing the body's immunity, so it is particularly suitable for patient rehabilitation.
A 1984 patent report in the United States was to use xylose-rich solid medium to cultivate shiitake mushrooms, and from the mycelium cultures, an anti-tumor glycoprotein with xylose as the main component could be obtained. By the 21st century, scientific research on the anti-tumor immunity of shiitake mushroom polysaccharides in medical institutions around the world has proved to be very numerous.
First, the structure of shiitake mushroom polysaccharides
Shiitake polysaccharide is a dextran isolated from the fruiting body of the umbelliferaceae fungus shiitake mushroom. Scientists have shown that the ordered conformation of the main chain and side chain of shiitake mushroom polysaccharides is a single spiral conformation, and the binding area of the colloidal structure will form a multi-spiral conformation, and its three-dimensional structure is a three-degree spiral of the right hand center, and the crystal lattice is hexagonal. The primary structure of shiitake polysaccharides has a β-(1→3)-connected pyran dextran backbone, in the main chain of glucose at the C6 position contains fulcrums (2 fulcrums for every 5 glucose), its side chain is composed of β-(1→6) bonds and β-(1→3) bonds connected glucose polymers, and also contains a small number of internal β-(1→6) bonds on the side chains.
Second, the effect of shiitake mushroom polysaccharides
2.1 Immunomodulatory effects
1. Shiitake polysaccharides are typical T cell activators
2. It can promote the production of interleukin
3. Promote the function of monocytes and are considered a special immune enhancer
4. It can promote the production of lymphocyte activation factors
5. Release various helper T cytokines, enhance the phagocytic rate of host peritoneal macrophages, and restore or stimulate the function of helper T cells
6. Promote antibody production and inhibit macrophages to release immune system inhibitors
Shiitake polysaccharides are typical T cell activators that promote the production of interleukins and promote the function of mononuclear macrophages, and are considered a special immune enhancer. Its immune effect is characterized by its ability to promote the production of lymphocyte activation factors, release various auxiliary T cytokines, enhance the phagocytic rate of host celiac macrophages, and restore or stimulate the function of helper T cells. In addition, shiitake polysaccharides can also promote antibody production and inhibit macrophages from releasing immune system inhibitors.
2.2 Antitumor effect
1. It can induce the production of an immunely active cytokine, so that the body's immune system is enhanced, and it has a defensive and killing effect on tumor cells
2. Combined with chemotherapeutic agents has the effect of attenuation and efficiency, mainly used to inhibit the occurrence, development and metastasis of tumors, and to improve the sensitivity of tumors to chemotherapy drugs through immunomodulatory effects or affecting the activity of some key enzymes
3. Improve the patient's physical condition and prolong their life
Shiitake polysaccharides can induce the production of an immunoactive cytokine, and under the combined action of these cytokines, the body's immune system is enhanced, which has a defensive and killing effect on tumor cells. The combination of shiitake polysaccharides and chemotherapeutic agents has the effect of attenuation and efficiency, mainly used to inhibit the occurrence, development and metastasis of tumors, through immunomodulatory effects or affect the activity of some key enzymes to improve the sensitivity of tumors to chemotherapy drugs, improve the patient's physical condition, prolong their life.
Shiitake polysaccharides are immune enhancers, anti-tumor adjuvants, which have no direct anti-tumor effect itself, but can further activate the immune system by activating the host's disease prevention mechanism, including activating the cytotoxic effect (ADMC) of killer T cells, macrophages, natural killer cells (NK) and antibody-dependent macrophages, and making the inhibited auxiliary T lymphocytes restore function and increase the synergistic effect of interleukin and interferon induction in the blood, which can further activate the immune system and have a significant protective effect on the liver. Single use or combination with other anti-tumor drugs have inhibitory proliferative effects on a variety of animal tumors, especially when used together with anti-cancer drugs such as fucoidan to improve immunity, the survival of patients is significantly longer than that of single use.
Shiitake polysaccharide is a biological response regulator, which is the fourth treatment method after the three major treatment methods of surgery, radiotherapy and chemotherapy, which produces the body's or cell-mediated anti-tumor effect by enhancing the body's anti-tumor immune defense response or changing the body's biological effect on tumor cells, and exerts an indirect anti-tumor effect.
Shiitake polysaccharides are generally used in combination with chemotherapy drugs. In 21 cases of gastric cancer patients with pleural fluid and ascites, intraluminal injection of shiitake polysaccharides for 4 weeks, 71% of patients had clinical effects. Shiitake polysaccharides have a good adjuvant therapeutic effect on patients with primary liver cancer, which can alleviate symptoms, reduce the toxicity of chemotherapy drugs, improve the immune function of patients, and prevent cancer cell metastasis. After treating 30 cases of liver cancer with shiitake polysaccharides, the improvement rate of the main symptoms was 82.8%, and the reduction of enlarged liver cancer accounted for 66.7%, and the recent effect was satisfactory. There were 5 cases of alpha-fetoprotein near normal and 3 cases of normal. No significant toxic side effects were found during treatment.
The effect of shiitake polysaccharides on prostate cancer is certain, and 69 patients received hormone therapy and oral shiitake polysaccharides, of which 33 patients were intramuscularly injected with shiitake polysaccharides for 3 months. Results: The survival time of 50% of the treatment group using shiitake polysaccharide was 48 months, and the survival time of the control group was 35 months, and the five-year survival rate was 43% and 29%, respectively, which were significantly different.
Shiitake polysaccharides were combined with chemotherapy drugs to treat 64 cases of advanced lung cancer, and the overall response rate was 66.6% in the combination group and 52.9% in the chemotherapy group alone (P<0.01). The combination of shiitake mushroom polysaccharides and chemotherapy drugs has a good effect on gastric cancer liver metastasis and breast cancer lung metastasis, and the volume of metastatic cancer is reduced after administration. Shiitake polysaccharides can inhibit the occurrence of cachexia in tumor patients and improve the quality of life of advanced patients. Conventional anti-tumor therapy often aggravates the occurrence of cachexia during the treatment of tumors, affecting the normal progress of treatment. Shiitake polysaccharides are ideal drugs that can fight both cancer and cachexia, and it can antagonize mice with anti-tumor necrosis factor induced food, drinking and weight gain.
The side effects of shiitake polysaccharide are mild and have no killing effect on normal cells, which is one of the characteristics of its superiority over cytotoxic anti-cancer drugs. Moreover, the drug can effectively antagonize the toxic side effects of chemotherapy drugs. In 35 patients with malignant pleural fluid, a small dose of cisplatin was injected intrathoracically, and the treatment group was given shiitake polysaccharides, and the total effective rate was similar in the two groups, but the incidence of toxic side effects in the treatment group was significantly lower than that in the control group. Shiitake polysaccharides can restore the decrease in erythrocytes caused by chemotherapy and stimulate the recovery of neutrophils, monocytes, lymphocytes and macrophages. Shiitake polysaccharide is a powerful clinical anti-tumor drug.
2.3 Anti-infective effects
1. The antiviral effect is related to its increase in NK cell activity, and the adhesion between the surface of polysaccharide molecules and the surface of pathogens intercepts the binding of pathogens to normal cell surface sugar molecules, thereby blocking their infection pathways
2. It has inhibitory effect on Abelson virus, adenovirus type 12 and influenza virus infection
3. Good drugs for the treatment of various hepatitis, especially chronic migratory hepatitis
4. It is used for drug-resistant tuberculosis and is also used to treat senile chronic bronchitis
According to reports, the antiviral effect of shiitake mushroom polysaccharides is related to its increase in NK cell activity, the surface of polysaccharide molecules adheres to the surface of pathogens, intercepts the combination of pathogens and normal cell surface sugar molecules, thereby blocking its infection pathway, shiitake polysaccharides have inhibitory effects on Abelson virus, type 12 adenovirus and influenza virus infection, and is a good drug for the treatment of various hepatitis, especially chronic migratory hepatitis.
2.4 Antiviral effects
1. It contains a double-stranded RNA that stimulates the body's reticulocytes and white blood cells to release interferons, which have antiviral effects
2. Its extract can inhibit the adsorption of herpes virus by cells, thereby preventing and treating various diseases caused by herpes simplex virus and cytomegalovirus
3. The sulfation of shiitake polysaccharides has anti-HIV (HIV) activity, which can interfere with the adsorption and invasion of retroviruses and other viruses, can restore T lymphocytes infected with HIV, stimulate macrophages, help produce antibodies to treat AIDS, and be safe without side effects