Kiyoshi Noda

A novel glycoprotein obtained from Chlorella vulgaris strain CK22 shows antimetastatic immunopotentiation

Abstract A glycoprotein extract (CVS), derived from the unicellular green alga Chlorella vulgaris, strain CK22, exhibited a pronounced antitumor effect against both spontaneous and experimentally induced metastasis in mice. Inhibition of tumor metastasis was enhanced when intratumor administration of CVS was followed by s.c. injection of CVS. Anti-metastatic immunopotentiation was observed in euthymic mice, but not in athymic nude mice. The antitumor activity of CVS was reflected in antigen-specific, T-cell-mediated immunity. Both CD4 and CD8 T cells contributed to the antimetastatic effects, as shown by in vivo depletion experiments with anti-T-cell subset antibodies. Furthermore, CVS caused the recruitment of T cells to the regional lymph nodes and their proliferation in these organs. The CD4-positive population, following CVS injection at the time of tumor rechallenge, displayed a pronounced increase in the proportion of T cells that were CD18 bright, CD44 bright, CD25+, CD54+, CD69+ or CD71+ in the lymph nodes. Thus, CVS induces T cell activation in peripheral lymph nodes in tumor-bearing mice. We conclude that CVS augments antimetastatic immunity through T cell activation in lymphoid organs and enhances recruitment of these cells to the tumor sites. Presurgical treatment with CVS might prevent metastasis or tumor progression.

Chlorella vulgaris culture supernatant (CVS) reduces psychological stress-induced apoptosis in thymocytes of mice

A glycoprotein prepared from Chlorella vulgaris culture supernatant (CVS) is a biological response modifier (BRM) which exhibits protective activities against tumor metastasis and 5-fluorouracil-induced immunosuppression. We here show that oral administration of CVS prevented significantly the apoptosis of thymocytes in mice undergoing psychological stress in a communication box. Mice were exposed to the emotional stress for 14 days by witnessing other mice being exposed to foot-shock. The numbers in thymocytes, especially CD4(+)CD8(+) population, were decreased significantly and apoptotic cells, as assessed by Annexin V expression, were reciprocally increased after the exposure to the psychological stress. C. vulgaris culture supernatant (CVS) administration significantly suppressed the increase in serum corticosterone level in the psychologically stressed mice. These results suggest that CVS prevents psychological stress and maintain homeostasis in the face of external environmental changes.

Toll-like receptor 2 is at least partly involved in the antitumor activity of glycoprotein from Chlorella vulgaris.

Toll-like receptors (TLR) are involved in innate immunity by recognizing various bacterial components. We have previously reported that an active substance of ARS-2 purified from the culture medium of Chlorella vulgaris was a glycoprotein with a molecular weight of 63,100 amu and that this glycoprotein expressed antitumor activity, with the protein moiety in ARS-2 being necessary for this antitumor activity. Here, we show that ARS-2 stimulated spleen-adherent cells from C3H/HeJ lacking functional TLR4 to produce interleukin-12 (IL-12) p40, whereas such cytokine production was significantly impaired in ARS-2-stimulated spleen-adherent cells from TLR2 knockout mice. The overexpression of mouse TLR2 (mTLR2) and mouse CD14 (mCD14) conferred the ARS-2 inducibility of nuclear factor-kappaB activation to human HEK 293 cells. These results suggest that TLR2 signaling is at least partly involved in the antitumor activity of the water-soluble antitumor glycoprotein from C. vulgaris.

Anti-androgen effects of extracts and compounds from Ganoderma lucidum

The 30% EtOH extracts of Ganoderma lucidum Fr. Karst (Ganodermateceae) showed weak 5alpha-reductase inhibitory activity and binding ability to androgen receptor. When LNCaP (lymph-node carcinoma of the prostate) cells were treated with the EtOH extracts, cell proliferation was inhibited. Treatment with the extracts significantly inhibited the testosterone-induced growth of the ventral prostate in castrated rats. These results showed that G. lucidum might be a useful ingredient in the treatment of androgen-induced diseases, such as benign prostatic hyperplasia or prostate cancer. From the 30% EtOH extracts, we isolated ganoderiol F, which showed binding activity to androgen receptor and inhibited LNCaP cell proliferation, as one of the active compounds in the 30% EtOH extracts.

A new type of biological response modifier from Chlorella vulgaris which needs protein moiety to show an antitumour activity

An immunopotentiator obtained from Chlorella vulgaris strain CK22, showed antitumour effects against various lines of syngeneic tumours, especially by intratumour administration. The immunopotentiator exhibited far greater antitumour activity against a rechallenged tumour than against the primary‐inoculated tumour in Meth A and BALB/c or CDF1 mouse systems. The antitumour effect was at least comparable to that of a streptococcal preparation, OK‐432, which has been widely used for clinical immunotherapy.

The effect of strain, growth stage, and cultivating condition of Ganoderma lucidum on 5α-reductase inhibition

The inhibitory effects of 102 methanol extracts of 40 mycelia, 9 culture fluids, and 53 fruiting bodies of 40 strains of Ganoderma lucidum on 5α-reductase were investigated. The methanol extract of the fruiting body of each strain was found to show the strongest 5α-reductase inhibitory activity among the extracts tested.

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.