Juzentaihoto, a Kampo medicine, enhances IL-12 production by modulating Toll-like receptor 4 signaling pathways in murine peritoneal exudate macrophages

Cnidium officinale Makino: Phytology, Phytochemistry, Toxicology, Pharmacology and Prescriptions (1967-2023)

Cnidium officinale Makino (COM), a perennial herbaceous plant in the Apiaceous family, widely distribute in Eastern Asia and Asia-Temperate. It has a long history application as a traditional medicine for invigorating the blood and removing blood stasis, and also has been employed to diet, pesticide, herbal bathing materials, the cosmetic and skin care industry. However, there has been no associated review of literature in the past half a century (1967-2023). By searching the international authoritative databases and collecting 229 literatures closely related to COM, herewith a comprehensive and systematic review was conducted. The phytology includes plant distribution and botanical characteristics. The phytochemistry covers 8 major categories, 208 compounds in total, and the quantitative determination of 14 monomer compounds, total polyphenols and total flavonoids. The clinical trial in pregnant women and toxic experiments in mice, the pharmacology of 7 aspects and 82 frequently used prescriptions are summarized. It is expected that this paper will provide forward-looking scientific thinking and literature support for the further modern research, development and utilization of COM.

Comparative study of the effects of the three kinds of Kampo-hozai: Ninjinyoeito, Hochuekkito, and Juzentaihoto on anxious and low sociability behavior using NPY-knockout zebrafish

Ninjinyoeito, Hochuekkito, and Juzentaihoto are the three types of Kampo-hozai used to support the treatment of various diseases by energizing patients through improved mental health. While Kampo-hozais are clinically used to improve mental energy decline, a comparison between their effects on neuropsychiatric symptoms like anxiety and sociability and the strength of their effects has not been conducted. Therefore, this study compared the effects of Ninjinyoeito, Hochuekkito, and Juzentaihoto on psychiatric symptoms using neuropeptide Y knockout (NPY-KO) zebrafish, a suitable animal model for anxiety and low sociability. Neuropeptide Y knockout zebrafish were fed a Ninjinyoeito, Hochuekkito, or Juzentaihoto-supplemented diet for 4 days. Then, sociability was analyzed using a three-Chambers test and anxiety-like behavior was evaluated using the cold stress and novel tank tests. The results showed that Ninjinyoeito treatment improved the low sociability of neuropeptide Y knockout, while Hochuekkito and Juzentaihoto did not. Neuropeptide Y knockout exhibited anxiety-like behaviors, such as freezing and swimming in the wall area under cold stress, but Ninjinyoeito treatment improved these behaviors. However, these anxiety-like behaviors were not improved by Hochuekkito and Juzentaihoto. Ninjinyoeito treatment also improved anxiety-like behaviors of neuropeptide Y knockout in the novel tank test. However, no improvement was shown in the Hochuekkito and Juzentaihoto groups. This trend was also confirmed in the low water stress test using wild-type zebrafish. This study exhibits that among the three types of Kampo-hozai, Ninjinyoeito is the most effective in psychiatric disorders associated with anxiety and low sociability.

Immunostimulatory properties of heat-resistant RNA in a decoction of Glycyrrhizae Radix

Research on the bioactive components of herbal medicines have been conducted mainly on the secondary metabolites of herbal plants. Accordingly, limited information is available on primary metabolites (carbohydrates, amino acids, lipids, and nucleic acids) and their biological effects. Here, we focused on the heat-resistant RNA of a decoction of Glycyrrhizae Radix and showed its immunostimulatory effects. The RNA activated NF-κB/AP-1 and induced TNF-α production in murine macrophages. Further analysis revealed that the RNA was around 90 nucleotides long. RNA sequencing (RNA-Seq) by next generation sequencing (NGS) showed that approximately 30% of the NGS reads were mapped to the genome of Glycyrrhiza uralensis, which is plant material of Glycyrrhizae Radix. Further analysis of the other 70% of reads indicated that the RNA contained RNA sequences that could be mapped to various microorganisms. Together, these results propose nucleic acids as a new research field in the bioactive components of herbal medicines.

Efficacy and Safety of Sipjeondaebo-Tang (Shi-Quan-Da-Bu-Tang) for Chronic Fatigue Syndrome: Study Protocol for a Multicenter, Randomized, Double-Blind, Placebo-Controlled Trial

Background. Sipjeondaebo-tang (SDT), also known as Shi-Quan-Da-Bu-Tang, is a treatment for both qi and blood deficiency syndromes in traditional Korean medicine. It is also used to treat chronic fatigue syndrome (CFS) in Korea. Herein, we present the protocol for a study to assess the efficacy and safety of SDT for treating CFS. Methods. This will be a multicenter, randomized, double-blind, controlled trial with two parallel-treatment arms: an SDT group and a placebo group. Ninety-six patients with CFS aged between 19 and 65 years will be recruited from two hospitals in Korea. Participants will be randomly allocated at a ratio of 1 : 1 between the two groups. Participants will receive 3 g doses of SDT or placebo thrice daily for 8 weeks. Follow-up evaluations will be performed for 4–6 weeks after the drug administration period. The primary outcome will be the rating of participants’ fatigue symptoms using the Checklist Individual Strength questionnaire. Outcomes will be assessed at baseline, week 4, and week 8, as well as during follow-up. An efficacy evaluation and safety assessment will be performed. This study will be based on the Consolidated Standards of Reporting Trials (CONSORT) guidelines and the Standard Protocol Items: Recommendations for Interventional Trials (SPIRIT) 2013 statement. This protocol and informed consent guidelines were reviewed and approved by the institutional review board of Kyung Hee University Korean Medicine Hospital at Gangdong in the Republic of Korea (KHNMCOH 2017-06-004-001). The protocol was registered with the Clinical Research Information Service. Written informed consent will be obtained from all study participants prior to enrollment in the study. Results will be published in a peer-reviewed journal and presented at a scientific conference. Discussion. This study is expected to provide novel, accurate information regarding the 38 efficacy and safety of SDT for CFS in adults. Trial Registration. This trial is registered with https://cris.nih.go.kr; CRIS identifier (KCT0002684) registered on February 9, 2018.

Effectiveness a herbal medicine (Sipjeondaebo-tang) on adults with chronic fatigue syndrome: A randomized, double-blind, placebo-controlled trial

Background

Sipjeondaebo-tang (SJDBT, Shi-quan-da-bu-tang in Chinese) is a widely prescribed herbal medicine in traditional Korean medicine. This study aimed to evaluate the effectiveness and safety of SJDBT for treating chronic fatigue syndrome (CFS).

Methods

Ninety-six eligible participants were randomly allocated to either the SJDBT or placebo groups in a 1:1 ratio. Nine grams of SJDBT or placebo granules were administered to the patients for 8 weeks. The primary outcome was the response rate, defined as the proportion of participants with a score of 76 or higher in the Checklist Individual Strength assessment. Other measurements for fatigue severity, quality of life, and qi/blood/yin/yang deficiency were included. Safety was assessed throughout the trial.

Results

At week 8, the response rate did not significantly differ between the groups (SJDBT: 35.4%; placebo: 54.2%; P =  0.101, effect size [95% confidence interval] = 0.021 [-0.177, 0.218]). However, the scores of the visual analogue scale (P =  0.001, -0.327 [-0.506, -0.128]), Fatigue Severity Scale (P =  0.020, 0.480 [0.066, 0.889]), and Chalder fatigue scale (P =  0.004, -0.292 [-0.479, -0.101]) for the SJDBT group showed significant improvements in fatigue severity at the endpoint. Quality of life was not significantly different. Furthermore, SJDBT significantly ameliorated the severity of qi deficiency compared to that in the placebo group. No serious adverse events were observed.

Conclusion

This trial failed to show a significant improvement in fatigue severity, as assessed by the CIS-deprived response rate. It merely showed that SJDBT could alleviate the severity of fatigue and qi deficiency in patients with CFS. However, the further study is needed to confirm the details.

Effect of Shin'iseihaito (Xinyiqingfeitang) on Acute Streptococcus pneumoniae Murine Sinusitis via Macrophage Activation

Streptococcus pneumoniae (S. pneumoniae) causes sinusitis. The general treatment of S. pneumonia sinusitis is by using antibiotics; however, one of their serious problems is the attenuation of their effect. Shin'iseihaito (Xinyiqingfeitang), a formula of Japanese traditional Kampo medicine, has been used for the treatment of sinusitis in Japan. In this study, we investigated the efficacy of Shin'iseihaito against S. pneumoniae-caused sinusitis in mice. Oral administration of Shin'iseihaito extract (SSHT) decreased the nasal colonization of S. pneumoniae in both prophylactic and therapeutic treatments, respectively, and the former was more effective than the latter. Histopathological analysis revealed that the epithelial tissue from S. pneumoniae-infected nose under SSHT treatment recovered the tissue destruction in comparison to infected nose. We also confirmed this result by scanning electron microscopic analysis. Murine peritoneal macrophages from SSHT-treated mice had significant phagocytic activity in comparison to those from untreated group. We also found that tumor necrosis factor-α, interleukin-1β, interleukin-6, and monocyte chemotactic protein-1 levels and the migration of macrophages from S. pneumoniae-infected mice with the treatment with SSHT were increased compared to those from untreated group. Our data suggest that Shin'iseihaito may be useful for the treatment of S. pneumoniae-induced sinusitis.

Suppressive Effect of Kampo Formula "Juzen-taiho-to" on Carbon Tetrachloride-Induced Hepatotoxicity in Mice

The aim of the present study was to investigate whether pretreatment with the Japanese herbal medicine, "Juzen-taiho-to" (JTX), had an ameliorative effect on carbon tetrachloride (CCl4)-induced hepatotoxicity through anorexia prevention. Mice injected with CCl4 exhibited severe anorexia. Moreover, CCl4 increased the plasma levels of hepatic injury markers (i.e., alanine aminotransferase and aspartate aminotransferase), lipid peroxidation, and hepatic Ca(2+) levels. Pretreatment with JTX recovered the CCl4-induced anorexia. In addition, JTX pretreatment decreased CCl4-induced plasma levels of hepatic injury markers. Increased Ca(2+) is a known indicator of the final progression to hepatocyte death, and CCl4-induced hepatotoxicity is mainly caused by oxidative stress. The present study indicated CCl4-induced lipid peroxidation and hepatic Ca(2+) content decreased with JTX pretreatment. Our results suggest that JTX has potential to protect of CCl4-induced anorexia, and the modulation of oxidative stress.

Randomized controlled trial of juzen-taiho-to in children with recurrent acute otitis media

OBJECTIVE

Recurrent acute otitis media (AOM) in young children is rapidly increasing worldwide. Repeated antibiotic use leads to antibiotic-resistant pathogen development. Complementary and alternative medicine approaches have been suggested as a supplemental treatment option to conventional antimicrobial medicine. This randomized, parallel-group, open-label, non-herbal medicine controlled trial assessed the efficacy of a traditional Japanese herbal medicine, juzen-taiho-to (JTT) for AOM prevention in otitis-prone children.

METHODS

Children prone to recurrent AOM aged 6-48 months were recruited from 26 otolaryngology clinics in Japan and received conventional AOM treatment based on Japanese guidelines with or without 2 daily oral doses of JTT (0.10-0.25g/kg/day). The mean number of AOM episodes, coryza episodes, and duration of total antibiotic administration per month were compared during 3-month intervention.

RESULTS

At least one episode of AOM was diagnosed in 71% of JTT-group and 92% of control participants during follow-up. JTT administration reduced the frequency of AOM episodes by 57% compared with children who received conventional treatment alone (0.61±0.54 vs. 1.07±0.72 AOM instances/month; P=0.005) and also significantly decreased number of coryza episodes (P=0.015) and total antibiotic administration (P=0.024).

CONCLUSIONS

This is the first report of recurrent AOM prevention by herbal medication. JTT appears to effectively prevent recurrent AOM in children. Subsequent double-blind studies are needed to confirm the beneficial effects of JTT on recurrent AOM and upper respiratory tract infections.

Effects of aged garlic extract and FruArg on gene expression and signaling pathways in lipopolysaccharide-activated microglial cells

Aged garlic extract (AGE) is widely used as a dietary supplement on account of its protective effects against oxidative stress and inflammation. But less is known about specific molecular targets of AGE and its bioactive components, including N-α-(1-deoxy-D-fructos-1-yl)-L-arginine (FruArg). Our recent study showed that both AGE and FruArg significantly attenuate lipopolysaccharide (LPS)-induced neuroinflammatory responses in BV-2 microglial cells. This study aims to unveil effects of AGE and FruArg on gene expression regulation in LPS stimulated BV-2 cells. Results showed that LPS treatment significantly altered mRNA levels from 2563 genes. AGE reversed 67% of the transcriptome alteration induced by LPS, whereas FruArg accounted for the protective effect by reversing expression levels of 55% of genes altered by LPS. Key pro-inflammatory canonical pathways induced by the LPS stimulation included toll-like receptor signaling, IL-6 signaling, and Nrf2-mediated oxidative stress pathway, along with elevated expression levels of genes, such as Il6, Cd14, Casp3, Nfkb1, Hmox1, and Tnf. These effects could be modulated by treatment with both AGE and FruArg. These findings suggests that AGE and FruArg are capable of alleviating oxidative stress and neuroinflammatory responses stimulated by LPS in BV-2 cells.

Immune adjuvant effect of Juzentaihoto, a Japanese traditional herbal medicine, on tumor vaccine therapy in a mouse model

Japanese traditional herbal medicine (Kampo) have been used to improve the general physical condition after surgery and to mitigate the side effects of radiation and chemotherapy in tumor patients. Juzentaihoto (JTT) consists of ten medical herbs, and is also called Shi-Quan-Da-Bu-Tang in Chinese herbal medicine. Among Kampo medicines, JTT has especially gained attention as a biological response modifier. Currently, clinical trials of various tumor vaccine therapies are being performed world-wide. However, tumor antigens that are inoculated as vaccines do not have high immunogenicity; thus, it is difficult to obtain an effective therapeutic effect. Thus, it is necessary to develop a tumor vaccine adjuvant that is more potent and very safe. In the present study, we examined the efficacy of JTT as an oral adjuvant when given together with tumor vaccines. As a result, JTT enhanced the phagocytic ability of OVA antigen and the presentation ability of OVA antigen in dendritic cells in vitro. Furthermore, tumor growth was markedly decreased, and the survival period was significantly prolonged in mice inoculated with mouse lymphoma, which is expressed with tumor model antigen. In conclusion, these findings suggest that JTT can be used with tumor vaccines as an immune adjuvant.

Suppression of Propionibacterium acnes-Induced Dermatitis by a Traditional Japanese Medicine, Jumihaidokuto, Modifying Macrophage Functions

Purpose. Macrophages serve as sweepers of microbes and inflammation-derived wastes and regulators of inflammation. Some traditional Japanese medicines are reported to have adjuvant effects by modifying macrophages. Our aim was to characterize the actions of jumihaidokuto (JHT) for treatment of skin inflammations including acne vulgaris, in which Propionibacterium acnes has pathogenic roles. Methods. Dermatitis was induced in rat ears by intradermal injection of P. acnes. JHT or prednisolone (PDN) was given orally, and ear thickness and histology were evaluated. The effects of constituents and metabolites of JHT on monocytes were tested by cell-based assays using the human monocytic THP-1 cell. Results. JHT and PDN suppressed the ear thickness induced by P. acnes injection. Histological examinations revealed that JHT, but not PDN, promoted macrophage accumulation at 24 h after the injection. PDN suppressed the macrophage chemokine MCP-1 in the inflamed ears, while JHT did not affect it. The JHT constituents liquiritigenin and isoliquiritin increased expression of CD86 (type-1 macrophage marker) and CD192 (MCP-1 receptor) and enhanced phagocytosis by THP-1. Conclusions. JHT suppressed dermatitis, probably by enhancing type-1 macrophage functions, with an action different from PDN. JHT may be a beneficial drug in treatment of skin inflammation induced by P. acnes.

Gastroprotective effect of the traditional herbal medicine, Sipjeondaebo-tang water extract, against ethanol-induced gastric mucosal injury

Background

Sipjeondaebo-tang, a traditional herbal medicine, has been reported to activate the immune response. Although, most research has focused on its anticancer activity. The purpose of this study was to determine whether Sipjeondaebo-tang exerts antioxidant activity against ethanol-induced gastric injury.

Methods

Gastric mucosal injury was induced by the oral administration of absolute ethanol at 5 mL/kg to rats after 18 h fast. Sipjeondaebo-tang water extract (SDTW; 200 mg/kg of body weight) was administered to rats 2 h before the oral administration of absolute ethanol. Gastric mucosal injury was evaluated by measuring the gastric injury, such as extent of lesions, malondialdehyde (MDA) concentration, glutathione (GSH) content and activities of antioxidant enzymes including catalase, glutathione peroxidase, glutathione S-transferase, glutathione reductase, and superoxide dismutase in stomach tissue.

Results

Oral administration of SDTW markedly decreased the damage by conditioning the gastric mucosa such as hemorrhage, hyperemia. Pretreatment with SDTW significantly reduced MDA concentration and significantly increased GSH content and the activities of antioxidant enzymes. In an acute toxicity study, no adverse effects of SDTW were observed at doses up to 5000 mg/kg/day.

Conclusions

SDTW may protect the gastric mucosa against ethanol-induced gastric mucosa injury. These results suggested that SDTW might also play an important role in the gastroprotection based on their antioxidant effect.

Juzentaihoto Failed to Augment Antigen-Specific Immunity but Prevented Deterioration of Patients' Conditions in Advanced Pancreatic Cancer under Personalized Peptide Vaccine

Juzentaihoto (JTT) is a well-known Japanese herbal medicine, which has been reported to modulate immune responses and enhance antitumor immunity in animal models. However, it is not clear whether JTT has similar effects on humans. In particular, there is little information on the effects of JTT in antigen-specific immunity in cancer patients. Here we conducted a randomized clinical study to investigate whether combined usage of JTT could affect antigen-specific immunity and clinical findings in advanced pancreatic cancer patients undergoing personalized peptide vaccination (PPV), in which HLA-matched vaccine antigens were selected based on the preexisting host immunity. Fifty-seven patients were randomly assigned to receive PPV with (n = 28) or without (n = 29) JTT. Unexpectedly, JTT did not significantly affect cellular or humoral immune responses specific to the vaccine antigens, which were determined by antigen-specific interferon-γ secretion in T cells and antigen-specific IgG titers in plasma, respectively. Nevertheless, JTT prevented deterioration of patients' conditions, such as anemia, lymphopenia, hypoalbuminemia, plasma IL-6 elevation, and reduction of performance status, which are frequently observed in advanced cancers. To our knowledge, this is the first clinical study that examined the immunological and clinical effects of JTT in cancer patients undergoing immunotherapy in humans.

Effect of hochuekkito on alveolar macrophage inflammatory responses in hyperglycemic mice

Diabetes mellitus reduces immunological activity and increases susceptibility to various infections. Hochuekkito (TJ-41) has been reported to improve the weakened physical condition of various chronic diseases. BALB/c mice were divided into three groups; groups A and B were fed a standard diet, and group C, a TJ-41 diet. Two weeks after starting these diets, hyperglycemia was induced in groups B and C by injection with streptozotocin. Two weeks later, bronchoalveolar lavage was performed. Toll-like receptor (TLR) ligands (TLR2: peptidoglycan, PGN; TLR4: lipopolysaccharide, LPS; TLR5: flagellin, FLG) were used to stimulate alveolar macrophages (AMs), and TNF-α production was measured. Under hyperglycemic conditions and PGN or FLG stimulation, TNF-α production from AMs was significantly reduced in group B compared with group A. However, treatment with TJ-41 (group C) significantly improved the impaired production of TNF-α. These results suggest that, under hyperglycemic conditions, TJ-41 can improve the inflammatory responses of AMs with stimulation of TLR ligands.

Stimulation of IFN-γ production by garlic lectin in mouse spleen cells: involvement of IL-12 via activation of p38 MAPK and ERK in macrophages

Several lectins, present in beans and edible plant products, have immuno-potentiating and anti-tumor activities. We here report the effects of garlic lectin purified from garlic bulbs on the production of cytokines such as interleukin-12 (IL-12) and interferon-γ (IFN-γ) in the mouse. Garlic lectin induced IFN-γ production in spleen cells in a bell-shaped time (24-60 h)- and concentration (0.25-2.0 mg/ml)-dependent manner. The maximal enhancement was observed at 36 h with 0.5 mg/ml of garlic lectin. The stimulatory effect of garlic lectin on IFN-γ production was completely inhibited by both actinomycin D and cycloheximide, an inhibitor of ribosomal protein synthesis and DNA-dependent RNA polymerase, respectively, and was associated with an increase in IFN-γ mRNA level. Garlic lectin also induced IL-12 production in mouse peritoneal macrophages in a concentration (0.25-1.0 mg/ml)- and bell-shaped time (3-24 h)-dependent manner. The lectin increased the phosphorylation of extracellular signal-regulated kinases (ERK) and p38 mitogen-activated protein kinase (p38 MAPK) in macrophages. Furthermore, specific pharmacological inhibitors of ERK kinase (U0126) and p38 MAPK (SB203580) also suppressed the production of IL-12 induced by garlic lectin. The present findings suggest that garlic lectin induces IL-12 production via activation of p38 MAPK and ERK in mouse macrophages, which, in turn, stimulates IFN-γ production through an increase in IFN-γ mRNA in the spleen cells.

Protective effect of Juzen-taiho-to on hepatocarcinogenesis is mediated through the inhibition of Kupffer cell-induced oxidative stress

Traditional herbal formulations, such as Juzen-taiho-to (TJ-48), are used extensively in medical practice in Asia even though their mechanism of action remains elusive. This study tested a hypothesis that TJ-48 is protective against hepatocarcinogenesis by impeding Kupffer cell-induced oxidative stress. Forty-eight patients were randomly assigned to receive TJ-48 (n = 10), or no supplementation (n = 38) for up to 6 years after surgical treatment for hepatocellular carcinoma (HCC). In addition, to investigate the mechanism of protective action of TJ-48, diethylnitrosamine-containing water was administered for 22 weeks to male mice that were fed regular chow or TJ-48-containing diet. Liver tumor incidence, cell proliferation, number of 8-hydroxy-2'-deoxyguanosine- or F4/80-positive cells, and cytokine expression were evaluated. Although most of the patients experienced recurrence of HCC, a significantly longer intrahepatic recurrence-free survival was observed in the TJ-48 group. In mice, TJ-48 inhibited the development of liver tumors, reduced oxidative DNA damage, inflammatory cell infiltration and cytokine expression. Administration of TJ-48 improves intrahepatic recurrence-free survival after surgical treatment of hepatocellular carcinoma. On the basis of animal experiments, we reason that the protective mechanism of TJ-48 involves inhibition of Kupffer cells. This leads to lower levels of pro-inflammatory cytokines and oxidants in liver which may slow down the process of hepatocarcinogenesis and improves hepatic recurrence-free survival in patients with HCC.

Novel functions of herbal medicines in dendritic cells: role of Amomi Semen in tumor immunity

Dendritic cells (DCs) have a major role in regulating immune responses, including tumor immunity and peripheral tolerance. In the present study, we identified novel functions of herbal medicines in DCs by screening 99 herbal medicines, most of which are among the 210 Chinese medicines approved by the Ministry of Health, Labour, and Welfare, Japan. Ethanol extracts were prepared, and a murine epidermal-derived Langerhans cell line, XS106, was used to screen the 99 extracts by analyzing major histocompatibility complex (MHC) class II expression. Amomi Semen (amomum seed), Polyporus (polyporus sclerotium), and Plantaginis Semen (plantago seed) potently activated XS106 and were selected for further analysis. The effects of these extracts on bone marrow-derived DCs (BM-DCs) generated in vitro were then analyzed using surface phenotype (MHC class II, CD80, and CD86) and interleukin (IL)-12p70 production as indicators. BM-DCs treated with Amomi Semen extract exhibited activated phenotypes and secreted IL-12p70. The activation level was similar to that induced by lipopolysaccharides. Finally, an E.G7-OVA tumor model (E.L4-OVA transfectant) was used to examine the anti-tumor effects of Amomi Semen extract. Vaccination of mice with a subcutaneous injection of BM-DCs treated with Amomi Semen extract and OVA peptide significantly inhibited the growth of tumor cells and prolonged survival time compared to controls. Furthermore, therapeutic effects were observed on established tumors. The inhibition rates for both the prophylactic and therapeutic protocols were comparable to those of lipopolysaccharides. These results indicate that Amomi Semen extract potently activate DCs and is potentially useful for DC vaccination.

Anti-tumor metastatic activity of beta-glucan purified from mutated Saccharomyces cerevisiae

The beta-glucans isolated from Saccharomyces cerevisiae (S. cerevisiae) enhance the innate immune system, but there is little evidence for its antitumor activity. To examine the antitumor and immunostimulating activities of beta-glucan (IS-2) purified from mutated S. cerevisiae, we made an experiment on innate immune response against metastasis of cancer cells by comparing with the beta-glucan from wild-type S. cerevisiae. In experimental lung metastasis of colon 26-M3.1 carcinoma or B16-BL6 melanoma cells, prophylactic administration of beta-glucan purified from mutated S. cerevisiae significantly inhibited lung metastasis in a dose-dependent manner. Furthermore, therapeutic administration of IS-2 also significantly inhibited the colon 26-M3.1 cell growth in mice. In an assay of liver and spleen metastasis produced by i.v. inoculation of L5178Y-ML25 lymphoma cells, IS-2 also significantly inhibited metastasis in CDF1 mice. Furthermore, pretreatment with IS-2 two days before tumor inoculation significantly prolonged the survival time of tumor-bearing mice. In an in vitro cytotoxicity analysis, IS-2 (up to 100 microg/ml) did not affect the growth of colon 26-M3.1 cells. In contrast, IS-2 enhanced splenocyte proliferating activity in a dose-dependent manner. Peritoneal macrophages stimulated with IS-2 produced various cytokines, such as IL-1beta, IFN-gamma, and IL-12. In addition, treatment with IS-2 (20 microg/mouse) induced tumoricidal activity of peritoneal macrophages against colon 26-M3.1 cells. In an assay for natural killer (NK) cell activity, IS-2 (20 microg/mouse, i.v.) significantly augmented NK cytotoxicity against Yac-1 tumor cells at 2 days after IS-2 treatment. The depletion of NK cells by injection of rabbit anti-asialo GM1 serum abolished the inhibitory effect of IS-2 on lung metastasis of colon 26-M3.1 cells. These data suggest that IS-2 inhibits tumor metastasis via activation of macrophages and NK cells.