Kikuo Nomoto

Antitumor effect induced by a hot water extract of Chlorella vulgaris (CE): Resistance to meth-A tumor growth mediated by CE-induced polymorphonuclear leukocytes

SummaryWhen a hot water extract of Chlorella vulgaris (CE) was injected into the peritoneal cavity of BALB/c mice inoculated with syngeneic Meth-A tumor cells, the survival times were strikingly prolonged. Furthermore, peritoneal exudate cells (PEC) rich in polymorphonuclear cells (PMN) obtained from normal mice 24 h after CE injection exhibited an antitumor effect in a Winn-type assay using normal recipients. Such an activity of PEC remained almost intact after T cell or macrophage depletion. However, such PEC did not express an antitumor effect in a Winn-type assay using irradiated recipients. It was suggested that CE-induced PEC, presumably PMN, expressed an antitumor effect in cooperation with a host- or recipient-derived element(s) sensitive to irradiation. The anti-tumor mechanism of CE may be different from that of OK-432, one of the biological response modifiers.

Augmentation of antitumor resistance by a strain of unicellular green algae, Chlorella vulgaris

SummaryGrowth of Meth-A tumor in CDF1 mice was inhibited significantly by injection of a hot water extract of a strain of Chlorella vulgaris (CE) into the tumor or into the subcutaneous tissue near the tumor. The augmentation of resistance by CE may require the participation of T cells and macrophages, since it was abolished or reduced in athymic nude mice or mice treated with carrageenan, a macrophage blocker. Mice treated with CE exhibited antigen-specific augmented resistance against rechallenge with tumor. Moreover, the antitumor effect of CE was comparable with that of Corynebacterium parvum, but its mechanism of effect might be different.

Effect of hot water extract of Chlorella vulgaris on cytokine expression patterns in mice with murine acquired immunodeficiency syndrome after infection with Listeria monocytogenes

We have previously reported that oral administration of hot water extract of Chlorella vulgaris (CVE) enhances resistance to Listeria monocytogenes through augmentation of Listeria-specific cell-mediated immunity in normal mice and mice with murine acquired immunodeficiency syndrome (MAIDS) caused by murine leukemia virus (MuLV) LP-BM5. To elucidate the mechanisms whereby CVE augments the cell-mediated immunity, we examined the expression patterns of mRNA for cytokines in normal and MAIDS mice given CVE orally after L. monocytogenes infection. The expression levels of IL-1 alpha, IL-12, GM-CSF, MIP and TNF alpha genes were significantly augmented in the peritoneal adherent cells by oral administration of CVE for 2 weeks before Listeria infection. The expression levels of gamma IFN and IL-12 mRNA were significantly higher in the spleen after Listeria infection in CVE-treated mice than in normal mice, while the expression of IL-10 mRNA in the spleen was decreased by CVE administration. In MAIDS mice, oral administration of CVE also augmented the expression of gamma IFN and IL-12 mRNA in the spleen after Listeria infection, while it rather reduced the expression of IL-10 mRNA. These results suggest that CVE may preferentially augment THI responses against Listeria via activation of macrophages to produce IL-12 and enhance host defence against Listeria infection both in normal and MAIDS mice.

Oral administration of hot water extracts of Chlorella vulgaris reduces IgE production against milk casein in mice

Hot water extract of Chlorella vulgaris (CVE) is a biological response modifier (BRM) which enhances resistance to Listeria monocytogenes through augmentation of helper T cell type 1 (Thl) responses producing gamma-interferon (gammaIFN). We show here that oral administration of CVE in mice suppressed the production of immunoglobulin (Ig)E against casein antigen accompanied by increased gammaIFN and IL-12 mRNA expression. Oral administration of CVE enhanced Thl response to casein in the spleen of casein immunized mice. CVE may be useful for prevention of allergic diseases with a predominant Th2 response.

Hot water extracts of Chlorella vulgaris reduce opportunistic infection with Listeria monocytogenes in C57BL/6 mice infected with LP-BM5 murine leukemia viruses

The bacterial elimination after infection with Listeria monocytogenes was impaired in mice with murine acquired immunodeficiency syndrome (MAIDS) by infection with LP-BM5 murine leukemia virus. Oral administration of hot water extracts of Chlorella vulgaris (CVE) restored the capacity of MAIDS mice to eliminate L. monocytogenes in association with improvement of the deteriorated immune response to L. monocytogenes. DTH response to Listeria in CVE-treated MAIDS mice was significantly higher than that of MAIDS mice after Listeria infection in association with increases in number of CD4+CD8- and CD4-CD8+ alpha beta T-cells in the infected sites. CVE might be effective in the treatment of opportunistic infection in retrovirus-induced immunodeficient patients.

Augmentation of the resistance against Listeria monocytogenes by oral administration of a hot water extract of Chlorella vulgaris in mice.

Oral administration of a hot water extract of Chlorella vulgaris(CVE)(20mg/mouse, 10 consecutive days) augmented the resistance against an i.p. infection with Listeria monocytogenes in mice. The numbers of bacteria in a CVE-administered group were significantly lower in the peritoneal cavity or spleen than those in a control group. FCM analysis revealed that gamma delta +Thy1.2+ cells in the nonadherent PEC from CVE-administered mice increased more prominently in number at the early stage on day 3 or on day 5 after infection as compared with those in control mice. The increment of gamma delta +Thy1.2+ T cells was also evident in spleen in CVE-administered mice at this stage after infection. The proportion of TCR alpha beta +Thy1.2+ T cells in the nonadherent PEC of a control group increased from 13% on day 0 to 49% at the late stage on day 10 after infection, whereas the proportion of TCR alpha beta +Thy1.2+ T cells in the nonadherent PEC in CVE-administered mice increased to 64% on this stage after infection in association with augmentation of DTH response to Listeria. These results suggest that CVE-administration effectively augment cell-mediated immunity against Listeria through the increment of gamma delta + T cells in the early phase and the increment of alpha beta + T cells in the late phase after listerial infection.

Accelerated restoration of the leukocyte number and augmented resistance against Eschericia coli in cyclophosphamide-treated rats orally administered with a hot water extract of Chlorella vulgaris

The effects of oral administration of a hot water extract of Chlorella vulgaris (CVE) on the restoration of the leukocyte number and on the resistance against Escherichia coli infection were examined in cyclophosphamide (CY)-treated rats. Male Fischer rats (F344/DuCrj) were administered orally 1000 mg/kg of CVE for 14 days and injected intraperitoneally with a single dose of CY (50 mg/kg) (day 0) one day after the 14th CVE administration. CVE was further administered continuously after CY treatment until the rats were sacrificed for analysis. The number of bone marrow cells in the CY + CVE group was significantly higher on day 7 after CY treatment than that in the CY-treated group. The number of spleen cells in the CY + CVE group became significantly higher on day 11 than that in the CY-treated group. In the peripheral blood, the number of PMN recovered efficiently in the CY + CVE group in comparison with the CY-treated group on day 7. When E. coli was injected i.p. into normal, CY-treated, and CY + CVE-treated rats on day 6, the difference in number of bacteria among these three groups was most prominent before 6 h, that is, the number in the CY + CVE group was remarkably lower than those in the CY-treated group, and even in the control group, among all organs so far tested.

Augmentation of the resistance against Escherichia coli by oral administration of a hot water extract of Chlorella vulgaris in rats.

In previous studies, we demonstrated that a hot water extract of Chlorella vulgaris (CVE) augmented the resistance against an intraperitoneal infection with Escherichia coli by its intraperitoneal, intravenous or subcutaneous administration. The augmented resistance appeared to be attributable to the enhanced activity of polymorphonuclear leukocytes (PMN). In this study, the effect of oral administration of CVE against Escherichia coli infection was examined. Male Fisher rats (F344/DuCrj) were administered 1000 mg/kg of CVE orally for 14 days and challenged with 2.7 x 10(8) Escherichia coli intraperitoneally. The numbers of living bacteria in the peritoneal cavity, blood, spleen and liver at 1, 6, and 24 h after the inoculation were counted. The bacterial numbers increased during 1-6 h and reached the peak at 6 h in both control and CVE-administered groups. The bacterial numbers decreased to an undetectable level at 24 h in both groups. In a CVE-administered group, the numbers of viable bacteria in each organ were remarkably lower than those in a control group in all organs so far tested. Whereas, the leukocyte numbers, especially PMN numbers, in the peritoneal cavity and peripheral blood maintained higher levels in the CVE-administered group at 6 h after E. coli inoculation. Chemiluminescent responses of peritoneal exudate cells induced by casein or E. coli were higher in a CVE-administered group. These results form the basis for the judgment that the degree of effectiveness of bacteria clearance from the peritoneal cavity shown by oral CVE administration may be strong enough to warrant developing this material as a new type of biological response modifier.

Immunopotentiating effects of a glycoprotein from chlorella vulgaris strain CK and its characteristics

Abstract Chlorella vulgaris strain CK, a unicellular greenalga, has been used as a health food for the past 30 years in Japan and in other countries. Oral administration of C. vulgaris results in several pharmacological effects, including augmenting host defenses in animal models and in human experiments. The oral administration of C. vulgaris showed clearprophylactic effects in stress-induced peptic ulcer models, presumably through the “immune-brain-gut” axis, and it also suppressed a Meth A tumor growth in an antigen-specific manner. C. vulgaris in active form, known as CVS, was purified from the culture supernatant of C. vulgaris and found to be a glycoprotein with a molecular weight of 63,100 amu. CVS contains 67% carbohydrate with a β-l,6-D-galactopyranose backbone and 35% protein. A protein moiety is essential for CVS to exhibit immunopotentiating activity, and 15-mer of the partial amino acid sequence at the NH2-terminus has been determined. CVS exhibited a pronounced antitumor effect against both spontaneous and experimentally induced metastasis by intratumor (i.t.) injection. Prophylactic effects of CVS were observed on 5-fluorouracil-induced myelosuppression and indigenous infection by subcutaneous injections. From these results, it became evident that CVS augments antimetastatic immunity through T cell activation in lymphoid organs and accelerates recruitment of these cells to the tumorsites. Presurgical treatment with CVS might prevent metastasis and/or the progression of residual tumors. CVS may also be beneficial for the alleviation of adverse effects of cancer chemotherapy, causing an early recovery of hematopoietic stem cells without affecting the antitumor activity of chemo-therapeutic agents.