The inhibitory effect of oral administration of lentinan on DSS-induced inflammation is exerted by the migration of T cells activated in the ileum to the colon.

Oral administration of lentinan ameliorated dextran sulfate sodium (DSS)-induced colitis through Dectin-1 receptor on intestinal epithelial cells. However, it is unclear where lentinan affects in the intestine to prevent the inflammation. We found that the administration of lentinan has induced migration of CD4+ cells from the ileum to the colon by using Kikume Green-Red (KikGR) mice in this study. This result suggests that the oral lentinan treatment could accelerate the migration of Th cells in lymphocyte from ileum into the colon during lentinan intake. Then, C57BL/6 mice were administered 2% DSS to induce colitis. The mice were administered lentinan daily via oral or rectal route before DSS administration. Its rectal administration also suppressed DSS-induced colitis, but its suppressive effects were lower compared to when orally administered, indicating that the biological responses to lentinan in the small intestine contributed to the anti-inflammatory effects. In normal mice (without DSS treatment), the expression of Il12b was significantly increased in the ileum by the oral administration of lentinan, but not by rectal one. On the other hand, no change was observed in the colon by either administration method. In addition, Tbx21 was significantly increased in the ileum. These suggested that IL-12 was increased in the ileum and Th1 cells differentiated in dependence on it. Therefore, Th1 predominant condition in the ileum could influence immunity in the colon and improve the colitis.

Mushroom polysaccharide lentinan for treating different types of cancers: A review of 12 years clinical studies in China.

Lentinula edodes has been used to improve general health for thousands of years in Asia. It is the second largest cultivated and the most popular edible mushroom in the world known as "Xianggu" in China and "Shiitake" in Japan. Lentinan is a polysaccharide extracted from Lentinula edodes. ß-Glucan is the major bioactive component in lentinan with immunostimulatory effect. The antitumor property of lentinan was reported in 1960s. Biochemical studies indicate that immunocytes can be activated by lentinan through multiple signaling pathways, such as TLR4/Dectin1-MAPK and Syk-PKC-NFκB pathways. Though it has been approved as an adjuvant therapeutic drug both in China and Japan for treating cancers since 1980s, a systematic review of clinical studies of lentinan has not been conducted elaborately. In this review, over 9474 reported lentinan-associated cancer treatment cases are evaluated and summarized from 135 independent studies in China during the past 12 years (2004-2016) based on CNKI (China National Knowledge Infrastructure), VIP (Chongqing VIP Chinese Scientific Journals Database) and Wanfang database. The 9474 reported lentinan-associated cancer treatment cases include lung cancer (3469 cases), gastric cancer (3039 cases), colorectal cancer (1646 cases), ovarian cancer (183 cases), cervical cancer (130 cases), Non-Hodgkin lymphoma (70 cases), pancreatic cancer (15 cases), cardiac cancer (15 cases), nasopharyngeal cancer (14 cases), duodenal cancer (1 case) and 110 cancer cases with no classifying patient information. Overall clinical data show solid effect of lentinan on improving the quality of life and on promoting the efficacy of chemotherapy and radiation therapy during cancer treatment.

The effect of lentinan combination therapy for unresectable advanced gastric cancer.

BACKGROUND: Developed as a biological response modifier (BRM), lentinan mitigates patients' symptoms by boosting the immune system. In combination with S-1 (tegafur, gimeracil, oteracil), lentinan is reported to mitigate adverse reactions to therapy for unresectable recurrent gastric cancer and prolong survival. However, there are few reports from actual clinical practice, and precise methods of using lentinan have not yet been established. This study retrospectively examined the usefulness of lentinan in patients. PATIENTS AND METHODS: The subjects of this study were 39 patients who were diagnosed with unresectable gastric cancer, based on preoperative examinations or findings at laparotomy in our Department. These patients underwent S-1/paclitaxel therapy. Nineteen of the patients received lentinan while 20 did not, and these two groups of patients were compared. RESULTS: There were no significant differences in patients' characteristics such as the male:female ratio, age at the start of chemotherapy, and staging classification of the 19 patients receiving lentinan and the 20 patients not receiving lentinan. Comparison of the two groups revealed no significant differences in overall survival time, but comparison of the duration of therapy revealed that therapy tended to be longer for the group taking lentinan than the group not taking lentinan. Adverse events were noted in 61.5% (24 patients) of the total patients group; such events tended to occur less frequently in the group receiving lentinan. CONCLUSION: Lentinan inclusion in therapy did not seem to prolong survival. Nevertheless, the duration of therapy tended to be longer for patients taking lentinan. This may be due to the fact that adverse events tended to occur less frequently in these patients during therapy. A decline in the incidence of adverse events increases the duration of therapy and improves the patients' quality of life (QOL); it may also prolong survival. Optimal methods of using lentinan need to be established.

[Combination chemotherapy of S-1/low-dose CDDP/lentinan for advanced gastric cancer].

Eight patients with inoperable advanced gastric cancer were treated with combination chemotherapy of S-1, low-dose cisplatin(CDDP)and Lentinan. S-1 80 mg/ m² was orally administered for 2 weeks followed by 1-week rest, CDDP 15 mg/ m² and Lentinan 2 mg/body were given intravenously on day 1 and 8. One complete response and four partial responses were observed for an overall response rate of 63%(5 of 8 patients). Only one patient developed over grade 3 toxicity leukocytopenia. Many patients could be maintained by long-term continuous treatment. Since combination chemotherapy of S-1/low-dose CDDP/Lentinan for advanced gastric cancer was very tolerable, it could be used for a long time.

Efficacy of orally administered superfine dispersed lentinan (beta-1,3-glucan) for the treatment of advanced colorectal cancer.

BACKGROUND: Lentinan (LNT) is an immune adjuvant medicine for advanced gastric cancer in Japan. Recently, an oral formulation of superfine dispersed lentinan (SDL) has become clinically available. To investigate the safety and effectiveness of SDL, a multi center clinical study in patients with advanced colorectal cancer was conducted. PATIENTS AND METHODS: Adverse events were assessed and the patients' quality of life (QOL) and the binding ability of peripheral blood monocytes (PBM) to LNT were also evaluated. RESULTS: Four grade 2 adverse events associated with SDL treatment were observed among the 80 patients. Adverse events associated with chemotherapy were observed in 9 out of the 64 chemotherapy-treated patients. Among the 48 patients assessed for QOL, the patients with low QOL scores before SDL treatment (n=23) reported a significant improvement in their QOL scores after 12 weeks of SDL administration. The rates of LNT-binding PBM in the QOL-improved group were significantly higher than those in the QOL-not-improved group (p<0.05). CONCLUSION: SDL was safe and effective for suppressing the adverse effects of chemotherapy as well as improving QOL. The binding ability of PBM to LNT appears to be a promising predictor of QOL improvement after SDL administration.

A multi-institutional prospective study of lentinan in advanced gastric cancer patients with unresectable and recurrent diseases: effect on prolongation of survival and improvement of quality of life. Kanagawa Lentinan Research Group.

BACKGROUND/AIMS: Lentinan is one of the host-mediated anti-cancer drugs which has been shown to affect host defense immune systems. Although the mechanisms involved in the antitumor effects of lentinan have been reported experimentally, the clinical outcome on prolongation of survival and improvement of quality of life in gastric cancer patients with unresectable or recurrent diseases has yet to be clarified. The aim of the present study was to investigate whether administration of lentinan prolonged survival or improved quality of life in these patients. METHODOLOGY: A multi-institutional randomized prospective protocol, consisting of patients administered tegafur and cisplatin (control group), and patients administered lentinan, tegafur and cisplatin (lentinan group), was performed. Quality of life was investigated using a questionnaire survey. RESULTS: Median survival was significantly longer in the lentinan group than in the control group (297 days vs. 199 days, p = 0.028). One-year survival rate was greater in the lentinan group than in the control group (49.1% vs. 0%). Total QOL score, especially appetite and sleep quality, was significantly improved with the administration of lentinan. CONCLUSIONS: Lentinan is considered to prolong survival and improved quality of life when gastric cancer patients with unresectable or recurrent diseases are treated in combination with other chemotherapeutic agents.

A placebo-controlled trial of the immune modulator, lentinan, in HIV-positive patients: a phase I/II trial.

Lentinan is a beta 1-->3 glucan isolated from Lentinus edodes (Shiitake mushroom) which has immune modulating properties. We have conducted two phase I/II placebo-controlled trials on a total of 98 patients. In one study at the San Francisco General Hospital (SFGH), ten patients each were administered 2, 5, or 10 mg of lentinan or placebo i.v. once a week for eight weeks. In the second study at the Community Research Initiative in New York (CRI), two groups of 20 patients each were administered 1 or 5 mg of lentinan i.v. twice a week for 12 weeks, and ten patients were administered placebo (vehicle containing mannitol plus dextran 40) i.v. twice a week. Entry criteria were an HIV positive test, CD4 levels of 200-500 cells, age 18-60 years, and without current opportunistic infections. This study confirms, in Caucasian subjects also, the good tolerability of lentinan observed in Japanese cancer patients. Side effects were mainly mild, especially when infusion was carried out over a 30-minute period. In the SFGH study, where administration was over a ten minute period, there were nine side effects severe enough to be reported to the FDA (one case each of anaphylactoid reaction, back pain, leg pain, depression, rigor, fever, chills, granulocytopenia and elevated liver enzymes) and there were four patients who discontinued therapy because of side effects. In the CRI study, where infusion was over a 30-minute period, there were no side effects reportable to the FDA and there were four dropouts due to side effects or personal preference. Most side effects resolved promptly after the discontinuation of medication, and all of them were relieved within 24 hours. Patients in the study have shown a trend toward increases in CD4 cells and in some patients neutrophil activity. Because of the small numbers, these values do not have statistical significance. Inasmuch as no side effects such as anemia, leukopenia, pancreatitis or neuropathy were seen, and in view of the positive effects of lentinan on certain surrogate markers (recognizing that these were small studies), we recommended a long-term clinical trial of lentinan in combination with didanosine (ddI) or zidovudine in HIV positive patients. Most patients in these trials did not have measurable p24 levels. In the CRI trials of ten patients with elevated p24 levels, eight on lentinan and two on placebo had decreased p24 levels. Of these decreases, those with lentinan and one with placebo were marked. These results were provocative and needed confirmation. Subsequent to this study, a trial of lentinan in combination with didanosine (ddI) showed a mean increase of 142 CD4 cells/mm3 over a twelve month period, in contrast to a decrease in CD4 cells in patients on ddI alone (Gordon et al. 1995).

Preclinical evaluation of lentinan in animal models.

Lentinan exerts prominent antitumor effects in allogeneic, syngeneic and autochthonous hosts and prevents chemical and viral carcinogenesis, and increases host-resistance to bacterial, viral and parasitic infections. Lentinan augments helper T cell mediated cytotoxic T cell activity, NK cell activity and humoral immune responses, and activates nonspecific cytotoxicity of macrophages in vivo. Lentinan is a representative of a unique class of T cell adjuvants, and has no toxicity. Therefore, lentinan is suitable for clinical application for cancer patients from the results in its preclinical animal model experiments.