Isolation and identification of a cytotoxic principle from Chrysosplenium grayanum Maxim. (Saxifragaceae) and its antitumor activities

A cytotoxic principle was newly isolated from Chrysosplenium grayanum Maxim. (Saxifragaceae) and identified as beta-peltoboykinolic acid (1) on the basis of spectral data. Cytotoxicity of compound 1 was tested against various human cancer cell lines in vitro, and antitumor effect of this compound was demonstrated on Meth.A mouse fibrosarcoma. The experiment of combined treatment with compound 1, mitomycin C, and OK-432 resulted in enhancing the antitumor effect against B16-BL6 mouse melanoma in C57BL/6 mice.

Phenoxazinone synthesis by human hemoglobin

We found that 2-amino-5-methylphenol was converted to the dihydrophenoxazinone with a reddish brown color by purified human hemoglobin, lysates of human erythrocytes, and human erythrocytes. The reddish brown compound was identified as 2-amino-4,4 alpha-dihydro-4 alpha,7-dimethyl-3H-phenoxazin-3-one by the measurement of NMR spectra, IR spectra, EI mass spectra, and absorption spectra. The changes in this phenoxazinone were studied under various conditions after mixing 2-amino-5-methylphenol with purified oxy- or methemoglobin, or with human erythrocytes. The production of 2-amino-4,4 alpha-dihydro-4 alpha,7-dimethyl-3H-phenoxazine-3-one from 2-amino-5-methylphenol was found to be tightly coupled with the oxidation of ferrous hemoglobin and reduction of ferric hemoglobin under aerobic conditions. By studying the production rates of the dihydrophenoxazinone and the oxido-reduction rates of ferrous and ferric hemoglobins during the reactions of ferrous or ferric hemoglobin with 2-amino-5-methylphenol under aerobic and anaerobic conditions, the reaction mechanism was extensively proposed.

Oxidative condensation of 2-amino-4-methylphenol to dihydrophenoxazinone compound by human hemoglobin

2-Amino-4-methylphenol was converted to a brownish yellow material by the lysates of human erythrocytes or purified human hemoglobin. The reaction proceeded oxidatively, coupled with the oxidation of hemoglobin. The major component of the brownish yellow material produced by oxidative condensation of 2-amino-4-methylphenol was identified as 3-amino-1,4 alpha-dihydro-4 alpha, 8-dimethyl-2H-phenoxazin-2-one on the basis of its spectral data including NMR spectra, IR spectra, EI mass spectra, and absorption spectra. The changes in 3-amino-1,4 alpha-dihydro-4 alpha,8-dimethyl-2H-phenoxazin-2-one during incubation of purified human hemoglobin and 2-amino-4-methylphenol were analyzed spectrophotometrically and by using HPLC. The reaction mechanism involved may be similar to that of actinomycin synthase, which oxidizes 2-amino-5-methylphenol to the dihydrophenoxazinone.

Antibody production useful for cytotoxicity against mouse MM2 tumor cells by peritoneal macrophages

We applied an antibody-dependent macrophage-mediated cytotoxicity (ADMC) test in order to analyze the effector mechanism of the host-mediated antitumor effects induced by OK-432. Adherent peritoneal exudate (PE) cells were obtained from each of high (C3H/He) and low (B10) responder mice treated with OK-432, and 51Cr-labeled MM2 tumor cells were used as target cells. The cytotoxic activity in vitro coincided well with the results obtained in in vivo antitumor experiments. When adherent PE cells from C3H/He mice reacted with anti-MM2 serum from B10 mice, the degree of ADMC was significantly lower than that obtained with the anti-MM2 serum from C3H/He mice. The removal of IgG1 from the anti-MM2 serum induced in B10 mice resulted in the enhancement of ADMC activity. Then mean level of IgG2 in each of anti-MM2 sera from C3H/He and B10 mice was higher than in normal serum, and the IgG1 level in the antiserum from B10 mice was also higher than that in the serum from normal B10 mice. The present work suggested that the active component(s) in anti-MM2 serum participating in ADMC was a specific antibody of the IgG2 subclass, and that the inhibiting factor(s) was the IgG1 subclass.

Inhibition of HIV-reverse transcriptase activity by some phloroglucinol derivatives

Four phloroglucinol derivatives, named mallotophenone (5-methylene-bis-2,6-dihydroxy-3-methyl-4-methoxyacetophenone), mallotochromene (8-acetyl-5,7-dihydroxy-6-(3-acetyl-2,4- dihydroxy-5-methyl-6-methoxybenzyl)-2,2-dimethylchromene), mallotojaponin (3-(3,3(dimethylallyl)5-(3(acetyl-2,4- dihydroxy-5-methyl-6-methoxybenzyl)-phloracetophenone) and mallotolerin (3-(3-methyl-2-hydroxybut-3-enyl)-5(3-acetyl-2,4- dihydroxy-5-methyl-6-methoxybenzyl)-phloracetophenone), have been tested for their ability to inhibit the activity of human immunodeficiency virus (HIV)-reverse transcriptase. Under the reaction conditions with (rA)n.(dT)12-18 as the template.primer, the enzyme activity was inhibited by approximately 70% in the presence of 10 micrograms/ml mallotochromene or mallotojaponin, whereas mallotophenone and mallotolerin were much less inhibitory to the enzyme. The enzyme activity was also inhibited, though to lesser extent, by these compounds under similar conditions with initiated MS-2 phage RNA as the template.primer. The mode of inhibition was, as analyzed with mallotojaponin, competivite with respect to the template.primer, (rA)n.(dT)12-18, and non-competitive with respect to the triphosphate substrate, dTTP. The Ki value of mallotojaponin for HIV-reverse transcriptase was determined to be 6.1 microM.

Inhibition of HIV-reverse transcriptase activity by asterriquinone and its analogues

Asterriquinone (ARQ; 2,5-bis-[1'-(1", 1"-dimethyl-2"-propenyl)- indol-3'-yl]-3,6-dihydroxy-1,4-benzoquinone) and its three analogues [i.e., 3,6-dihydroxy-2-[2'-(1", 1"-dimethyl-2"-propenyl)-indol-3'-yl]-5-[1', 7'- (1",1"-dimethylpropano)-indol-3'-yl]-1,4-benzoquinone (B1-4), 3,6-dihydroxy-2-[2'-(1", 1"-dimethyl-2"-propenyl)-indol-3'-yl]-5-indol-3'-yl-1,4-benzoquinone (C1-1) and 3,6-dihydroxy-2,5-diindol-3'-yl-1,4-benzoquinone (D-1)] were found to be strong inhibitors of the activity of reverse transcriptase from human immunodeficiency virus type-1. Under the reaction conditions employed, the enzyme activity was inhibited by more than 70% in the presence of 10 microM each of these compounds. The mode of inhibition by these compounds was competitive with respect to the template.primer, (rA)n.(dT)12-18, and noncompetitive with respect to the triphosphate substrate, dTTP. The Ki values of HIV-1 reverse transcriptase were determined to be 2.3, 1.5, 0.1 and 0.3 microM for ARQ, B1-4, C1-1 and D-1, respectively.

Immune reactivity in bronchogenic carcinoma and its relation to 5-year survival rate

We performed a prospective study on the correlation of various parameters of the immune response with the 5-year survival rate in patients with bronchogenic carcinoma. Parameters were initially examined before starting treatment. Delayed hypersensitivity skin tests, lymphoblastogenesis, natural killer (NK) cell activity, and interleukin-2 (IL-2) production were employed to assess immune competence. Each reaction was classified into four or five grades in accordance with intensity; the 5-year survival rate of the patients showing each grade of the immune response was calculated. A correlation between response before treatment and the survival rate was most clearly noted for lymphoblastogenesis. The skin tests and the NK cell activity showed poorer correlations, and no exact correlation was noted between the IL-2 production and the immune response.

Interaction of asterriquinone with deoxyribonucleic acid in vitro

The interaction of asterriquinone (ARQ), a novel antitumor agent isolated from Aspergillus fungi, with deoxyribonucleic acid (DNA), has been studied. The binding of ARQ in vitro with DNA (calf thymus) was ascertained by its behavior in gel filtration using a Sephadex G-25 column at pH 5.4. Some ARQ analogs having no, or less, antitumor activity did not exhibit any evidence of interaction with DNA under the same condition. From the results obtained in this work, the pKa value of ARQs seemed to be critical between 6 and 7 for their binding to DNA and for exhibition of antitumor activity. Also, ARQ showed serious membrane deformations and an inhibitory effect on the membranous adenosine triphosphatase of Ehrlich carcinoma cells.

Augmentation of various immune reactivities of tumor-bearing hosts with an extract of Cordyceps sinensis

In order to enhance general reactivity of immune system in the tumor-bearing host, we employed extract of Cordyceps sinensis (CSE) as a biological response modifier. Cordyceps sinensis is an interesting material produced by a kind of mushroom parasitic to larval moths and was used to hasten recovery from exhaustion in ancient China. In this experiment, C57BL/6 mice implanted subcutaneously with syngeneic EL-4 lymphoma cells were employed as the host. Oral administration of the extract leads to a reduction of tumor size and prolongation of the host survival time. As judged by plaque-forming cells against T-dependent (sheep erythrocytes) and T-independent (bacterial lipopolysaccharide) antigens, CSE showed to augment the antibody responses. As for the activities of peritoneal macrophages, chemotaxis was dramatically depressed within a few days after EL-4 transplantation up to the end of life, but treatment with CSE at -14, -7, -4, +4, +7 and +10 days after the tumor transplantation augmented the activity about four times stronger than that of control. Phagocytic activity of macrophages was also decreased in tumor-bearing mice treated with cyclophosphamide (100 mg/kg) 3 and 5 days after tumor transplantation. But administration of CSE restored the activity to more than the normal level. The overall efficacy of CSE was tested with protective activity against systemic infection by Salmonella enteritides. The tumor-bearing mice receiving this medicine lived significantly longer than any other groups without CSE.

Changes in immunological parameters in lung cancer patients undergoing immunotherapy with streptococcal preparation OK-432

We have studied the immunological status of patients treated with streptococcal preparation OK-432. Two KE of OK-432 was injected intramuscularly once every week for more than three years unless the patients died. The natural killer (NK) activity in those patients who underwent curative surgery for lung cancer and had no sign of recurrence was significantly increased (P less than 0.01) during the OK-432 treatment. However, the NK activity in the patients who had persistent disease (non-resected cases, incompletely resected cases or recurrent cases) was not significantly increased in comparison with that before the immunotherapy. Also, in the cases with no clinical symptoms of recurrence, both the lymphoblastogenetic reactions to the mitogens and the IL-2 production were significantly enhanced (P less than 0.01) during the administration of OK-432. Reactions in the SU-PS (polysaccharide taken from the cell-wall fraction of the Streptococcus pyogenes SU strain and containing 7.2% of protein) skin-test appeared to significantly correlate with the immunological status of the patients under OK-432 therapy, but the PHA and PPD skin reactions showed no definitive enhancement. The survival rate of the patients whose SU-PS skin tests were positive during the OK-432 immunotherapy was significantly higher (P less than 0.01) than that of the patients with negative reactions.

Antitumor activity of an extract of Cordyceps sinensis (Berk.) Sacc. against murine tumor cell lines

A warm water-extract (ECS) prepared from dried Cordyceps sinensis (Berk.) Sacc., a Chinese traditional medicine, was tested for antitumor activity in vivo and in vitro. Ehrlich ascites carcinoma cells (EAC), allogeneic to ICR mice and Meth A fibrosarcoma (Meth A), syngeneic to BALB/c mice were used as the target tumor cell lines. Mice were inoculated i.p. with 1 x 10(6) EAC or 1 x 10(5) Meth A on Day 0, and ECS or saline (control) was injected i.p. to the mice from Day 1 to Day 4. ECS-treatment increased the median survival time of the allogeneic mice inoculated with EAC to 316% of the control. Eight of the 10 ECS-treated mice survived on the 60th day (Day 60) after EAC implantation. ECS-treatment also increased the median survival time of the syngeneic mice inoculated with Meth A to 312% of the control. Half of the ECS-treated mice survived on Day 60. On the other hand, no cytotoxic effect of ECS was found on either EAC or Meth A in vitro. The antitumor effect of ECS seen in the allogeneic mice was significantly reduced when the mice received whole body X-irradiation (5 Gy) before EAC implantation. These results suggest that the antitumor effect of ECS may be mediated through its immunomodulating action.

In vivo localization of radiolabeled monoclonal antibody to carcinoembryonic antigen (CEA) in a CEA-producing tumor--comparison with polyclonal antibody

To compare accumulation of the 125I-labeled antibodies (anti-carcinoembryonic antigen (CEA) monoclonal antibody and polyclonal antibody) to a CEA-producing tumor (SC-2-JCK), an in vivo localization study was performed in nude mice. The tumor-to-blood ratio at 120 hours after injection rose to 4.6 for the monoclonal antibody, but remained at 1.3 for the polyclonal antibody. However, no differences were noted between the antibodies up to 72 hours after injection. In autoradiograms, selective accumulation of the tracer was noted in the tumor for both antibodies. However, no superiority or inferiority of imaging for either of the antibodies could be definitely determined.

Biological active macrocyclic diterpenoids from chinese drug "Fáng Féng Cáo"; II. Derivatives of ovatodiolids and their cytotoxity

Isolated macrocyclic diterpenoids, ovatodiolide ( 1), 4, 5-epoxyovatodiolide ( 2), anisomelic acid ( 3), 4, 7-oxycycloanisomelic acid ( 4), and 4-methylene-5-oxoanisomelic acid ( 6), from the Chinese crude drug "Fáng Féng Cáordquo;, and the derivatives of the isolated compounds were tested for their growth inhibiting activities in culture of KB cell line. Besides, the effects of 1 on Ehrlich carcinoma in mice are reported.

Antitumor effect and structure-activity relationship of asterriquinone analogs

Asterriquinone (ARQ), a metabolic product from Aspergillus terreus IFO 6123, showed an inhibitory effect on some transplantable animal tumors, Ehrlich carcinoma, ascites hepatoma AH13 and mouse P388 leukemia, but had little or no effect on Yoshida sarcoma, ascites hepatoma AH109A and mouse L1210 leukemia. ARQ also inhibited the growth of HeLa cells in monolayer culture. Although metabolic products from Aspergillus terreus var. africanus IFO 8835 were almost ineffective against Ehrlich carcinoma, some chemically modified ARQ-like compounds were found to have potent inhibitory activity against the growth of the carcinoma in mice. The presence of free hydroxyl groups in the benzoquinone moiety and the number and position of tert-, iso-pentenyl, or both pentyl groups seem to be important in relation to the antitumor activity.

Reduced antitumor and immune-adjuvant activities of the sub-cellular fractions from Group A Streptococcus

The sub-cellular fractions from Group A streptococcus (Su-strain) were prepared, and their antitumor and biological activities were examined. The cell wall fraction (CWF) and the protoplast membrane fraction (PMF) were slightly effective in retarding the growth of Ehrlich ascites carcinoma in outbred ddY mice when either fraction was used in combination with 5-FU. The cytoplasmic particle fraction (CPF) and the cytoplasmic soluble fraction (CSF), however, were not effective. In the B6D2F1 mice-L 1210 leukemia system, none of the subcellular fractions were beneficial even when combined with 5-FU. Further, the antitumor effect of OK-432 was completely abolished by disruption of the preparation, indicating that antitumor activity of OK-432 may depend on the structural integrity of the cocci in the preparation. Despite the general lack of anti-tumor activity in the mouse systems, the subcellular fractions, including those of OK-432, inhibited the growth of Yoshida sarcoma cells in culture and the uptake of [2H]-UR and [3H]-TdR by L 1210 cells in vitro. The immunopotentiating activities of these fractions, however, were demonstrated to be markedly diminished as compared with those of OK-432 and heated Su-cocci (60 degrees C, 30 min). The present study, therefore, shows that the decreased antitumor activity of the subcellular fractions closely correlate to the decrease of their immunopotentiating activities.

Effect of OK-432 on immunization with mitomycin-C-treated L1210 cells

The pretreatment of B6D2F1 mice with OK-432 alone was not so effective to retard the growth of L1210 leukemia, and the leukemic cell was poorly immunogenic in the mice. However, when OK-432 was given by ip injection in combination with mitomycin-C-treated L1210 cells, the growth of L1210 leukemia was significantly retarded and some mice did not "take" the leukemia. Meanwhile, BCG was also effective in this respect. Differences in properties as an immunopotentiator between OK-432 and BCG were suggested by the experiments of in vitro cytotoxicity test of spleen cells.

Antitumor activity of protoplast membrane from group A streptococcus

Cytoplasmic membrane of Group A streptococcus has been obtained by treatment of the cells with a phage-associated lytic enzyme to dissolve the streptococcal cell wall, followed by shocking osmotically. The protoplast membrane fraction (PMF) remained as a distinct homogeneous structure in the electron micrograph and analysis showed a low rhamnose content. Febrile response produced by PMF was very slightly exhibited or not at all. PMF showed weak suppression against the growth of rat Yoshida sarcoma cells in culture and inhibition of [3H]-uridine incorporation into the sarcoma cells in vitro. In vivo antitumor experiments demonstrated that PMF has a mild inhibiting effect against mouse Ehrlich ascites carcinoma, though there was not observed a definite correlation between survival rate and dose level. Antitumor activity of PMF was thermo-labile and was strikingly abolished by treatment with a bacterial enzyme, Nagarse, but not so much by alpha-chymotrypsin.

Studies on the properties of a streptococcal preparation OK-432 (NSC-B116209) as an immunopotentiator. I. Activation of serum complement components and peritoneal exudate cells by group A streptococcus

The inhibition of transplanted tumors in animals, which were previously injected with a streptococcal preparation, OK-432, has been suggestible to be induced by direct or host mediated effects. In this paper, it was examined of immunopotentiating ability of Group A streptococcus (Su-strain), which is a active component of OK-432, with respects to reticuloendotherial system and serum complement components. Human fresh serum incubated with the heated streptococcus (HSu-coccus) was analyzed by means of immunoelectrophoresis. Activated component of C3 proactivator was observed in gamma region as immunoprecipitin line developed by rabbit anti human C3 proactivator serum, and conversion of C3 component (beta1C) to beta1A was observed in alpha region by rabbit anti human beta1C/beta1A serum. The activation of serum complement components might be occurred via alternate pathway, because EDTA inhibited the activation but EGTA did not. Meanwhile, the peritoneal exudate cells from mice injected intraperitoneally with HSu-coccus were examined with respects to cell population and their antitumor effect. On the 7th day after injection of HSu-coccus, about 90% of the peritoneal cells was lymphocytes, and 70% of these lymphocytes was susceptible to rabbit anti mouse thymus cell serum or to AKR anti thetaC3H serum. When L1210 leukemia cells preincubated with these peritoneal cells were inoculated intraperitoneally into BALB/c mice, the leukemic cells could not allowed the growth, resulting in prolongation of life-span of the experimental animals. These results suggested that nonspecific effector activity of T-derived lymphocyte induced by HSu-coccus could be one of the factors participating in antitumor activity of OK-432. Additionally, the results obtained with OK-432 were most the same as those with HSu-coccus in these respects. Further, the relation between the stimulation of leucocytes and activation of complement components was discussed.

Isolation and properties of a streptococcal hemolysin formed in the presence of colistin

The strains of beta-hemolytic streptococci capable of producing streptolysin S, Su and Blackmore, were found to be useful in acquiring CIH (colistin-induced hemolysin), while C203U strain, which produces only streptolysin O, was ineffective in this respect. In these experimental series, much amounts of coccal cells from exponential phase of culture were necessary for obtaining good results and for its reproducibility. Further experiments showed that an oligoribonucleotide, rich in guanylic residu, separated by DEAE-cellulose column chromatography could be favourably compared with RNase-core in production of CIH in the medium. Yield of this hemolysin was fully dependent upon the concentration of K+ (100 mM), Mg2+ (10 mM) ions and maltose (5 mM) contained in the reaction medium, respectively. When one of three components was omitted, CIH was not obtained, even though colistin and oligoribonucleotide were present. Additionally, crude preparation of CIH was fractionated on DEAE-cellulose column, resulting in isolation of two peaks (F-I and F-II) with hemolytic activity. Considering the response of two hemolytic fractions to various inhibitors and activators, F-II is likely to correspond to streptolysin S, while F-I may, at least, be a segment differed from the streptolysin, S and O.