Biomedical subjects

N Motohashi

Publications and source records attributed to N Motohashi.

At least 163 records · Page 9Linked to original sources

PubMedDate not supplied

Biological activity of a fruit vegetable, "Anastasia green", a species of sweet pepper.

Russian green sweet pepper (Anastasia Green) was successively extracted with hexane, acetone, methanol and 70% methanol and the extracts were further separated into a total of twenty fractions by silica gel or ODS column chromatographies. The biological activities of these extracts and fractions were compared. The extracts and fractions showed higher cytotoxic activity against two human oral tumor cell lines than against normal human gingival fibroblasts, suggesting their tumor-specific action. Several fractions [H3, H4, A4] reversed the multidrug resistant gene (MDR1) against L5178 mouse T-cell lymphoma more effectively than (+/-) verapamil (positive control). All extracts and fractions showed no anti-human immunodeficiency virus (HIV) nor anti-Helicobacter pylori activity. These data suggest the medicinal importance of an Anastasia Green extract.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMedDate not supplied

Relationship between cytotoxic activity and radical intensity of isoflavones from Sophora species.

Among 11 isoflavones tested, genistein [YS13] produced higher cytotoxic activity against human oral tumor cell lines (HSC-2, HSG) than against normal cells (human gingival fibroblast, HGF), suggesting its tumor-specific action. Electron spin resonance (ESR) spectroscopy showed that YS13 did not produce radical, nor scavenged O2*- generated by hypoxanthine-xanthine oxidase reaction system, suggesting that radical-mediated oxidation mechanism is not be involved in the YS13-induced cytotoxicity. Addition of one prenyl group produced YS18 and YS19 with higher anti-Helicobacter pylori activity. Addition of two prenyl groups produced YS21 with the highest cytotoxic activity but lower tumor-specificity. Since YS21 produced the highest amount of radical and most efficiently scavenged O2*-, this compound may induce cytotoxicity by radical-mediated oxidation mechanism. All isoflavones failed to induce anti-human immunodeficiency virus (HIV) activity. These data suggest the medicinal efficacy of isoflavones.

Animals↗

PubMedDate not supplied

Antioxidative activity of Allium victorialis L. extracts.

Allium victorialis L. (Liliaceae, "Hon-Gyoujya Nin-Niku" in Japanese) was successively extracted with hexane, acetone, methanol and 70% methanol and the extracts were further separated into a total of twenty-five fractions by silica gel and ODS column chromatographies. The biological activities of these four extracts and 25 column fractions were compared. The cytotoxic activity of all extracts and fractions against two oral tumor cell lines was significantly higher than that against normal human gingival fibroblasts, suggesting their tumor-specific action. Three methanol column fractions [M2, M3, M6] and a 70% methanol column fraction [70M6] most effectively reversed the multidrug resistance (MDR) against L5178 mouse T cell lymphoma. The electron spin resonance (ESR) spectroscopy showed that methanol column fractions and 70% methanol extracts produced the highest amount of radical(s) and most efficiently scavenging O2*-, generated by the hypoxanthine-xanthine reaction system, suggesting that the same substances in these fractions display both prooxidant and antioxidant properties. They showed no anti-human immunodeficiency virus (HIV) or anti-Helicobacterpylori activity. These data suggest the medicinal efficacy of Allium victorialis extract.

Allium↗

PubMedDate not supplied

Antimicrobial activity of prenylflavanones.

Among two flavanones [YS01, YS02] and eight prenylflavanones [YS03-YS10], preliminary screening with fifteen test bacterial strains showed that YS06 was the most active agent. YS06 exhibited highly significant antimicrobial action when tested against 228 bacterial strains comprising two Gram-positive and six Gram-negative genera. The in vitro susceptibility test was carried out by determining the minimum inhibitory concentration (MIC) of YS06 by agar dilution technique. Twenty-two out of fifty strains of Staphylococcus aureus were inhibited at 25 to 50 micrograms/mL of the agent. YS06 also inhibited strains of Salmonella, Shigella and a few strains of Escherichia coli strains were also highly sensitive to YS06, while Kleibsiella spp. and Pseudomonas aeruginosa were much less sensitive. In in vivo study, YS06 offered significant protection (p < 0.001 according to chi-square test) to Swiss albino mice (challenged with 50 minimum lethal dose (MLD, virulent bacterium) at concentrations of 160 and 80 micrograms/mouse.

Anti-Bacterial Agents↗

PubMedDate not supplied

Relationship between resonance energy and carcinogenic activity of benz[c]acridines.

In order to investigate the correlation between the carcinogenic activity of benz[c]acridines and the electron density, the Huckel orbital method was used. Resonance energies, circuit resonance energies and bond currents of benz[c]acridines were calculated by Aihara's TRE theory. It was shown that these compounds had very stable aromatic characters with positive resonance energies and that the resonance energies per pi-electron values for the compounds with lack of the double bond corresponding to the K-region from the parent skeleton were more stable than those of their parent compounds. 7-Methyl-benz[c]acridine derivatives with the methyl groups at 7-, 7, 9-, 7, 10-, 7, 11-, 7, 9, 10-, or 7, 9, 11-positions except 5, 7-dimethylbenz[c]acridine had potent carcinogenic activity and significantly lower resonance energy per pi-electron.

Acridines↗

PubMedDate not supplied

Induction of anti-Escherichia coli activity in mice by phenothiazines, benzo[a]phenothiazines and benz[c]acridines.

The abilities of 14 phenothiazines, 8 benzo[a]phenothiazines and 12 benz[c]acridines to induce anti-Escherichia coli activity in mice were compared. Pretreatment with several benzo[a]phenothiazines or benz[c]acridines protected mice from lethal infection of Escherichia coli in a dose-dependent manner, whereas most of the phenothiazines induced much weaker anti-Escherichia coli activity. However, direct contact of Escherichia coli with these compounds or their administration just after bacterial inoculation were ineffective. These data suggest the immunopotentiation activity of benzo[a]phenothiazines and benz[c]acridines.

Acridines↗

PubMedDate not supplied

Relationship between pi-electron distribution and anticancer activity of benzo[a]phenothiazines.

In order to study the correlation between the anti-tumor activity of benzo[a]phenothiazines and the electron densities, the Huckel orbital method and modified-neglect-of-diatomic overlap (MNDO) orbital method were used. 9-Methyl-12H-benzo[a]phenothiazine (2), which showed the most potent anticancer activity among benzo[a]phenothiazines, had the highest charge of nitrogen atom (QN), L-region (QL) and M-region (QM) in the molecule. The other derivatives, which showed weaker anticancer activity, had a much reduced value of these charges (QN, QL, QM). The data suggest that stability of pi-electron in 1 benzene ring and 1 naphthalene ring in the benzo[a]phenothiazine skeleton might be responsible for the induction of anticancer activity.

Animals↗

PubMedDate not supplied

Inhibition of tumor induction in tobacco by Agrobacterium tumefaciens and nodulation induced by Rhizobium meliloti in the presence of phenothiazines and structurally related compounds.

Plasmids of Agrobacterium tumefaciens and Rhizobium meliloti carrying Kanamycin resistance genes were eliminated from 1.4 to 0.2% of the growing bacterial cultures by promethazine and imipramine. As a result of plasmid elimination, the A. tumefaciens plasmidless isolate was not able to induce crown gall tumor on tobacco plants. The plasmidless R. meliloti strain failed to induce nodule formation on alfalfa plants. The efficiency of nodulation was decreased when the bacteria were grown in the presence of the drugs. The antiplasmid effects of the drugs were not prevented by opines, (nopaline and octopine) in Escherichia coli F'lac cells.

Agrobacterium tumefaciens↗

PubMedDate not supplied

Antimicrobial activity of phenothiazines, benzo[a]phenothiazines and benz[c]acridines.

The abilities of 14 phenothiazines, 8 benzo[a]phenothiazines and 12 benz[c]acridines to induce an antibacterial effect against Escherichia coli K12 were compared. Several phenothiazines, which showed antiplasmid activity, displayed the most potent antibacterial activity. All benz[c]acridine derivatives were moderately antibacterial, whereas benzo[a]phenothiazines were inactive. The active phenothiazine derivatives had more potent inhibitory activity against fungi, including phytopathogen filamentous, human pathogen filamentous fungi and yeasts, than against gram-positive and -negative bacteria. Taken together with previously reported data, the induction mechanism of antimicrobial and antiplasmid activity by these compounds seems to be different from that of antitumor, differentiation-inducing and carcinogenic activity.

Acridines↗

PubMedDate not supplied

Antiplasmid activity of phenothiazines, benzo[a]phenothiazines and benz[c]acridines.

Various synthetic derivatives of phenothiazines, benzo[a]phenothiazines and benz[c]acridines were compared for their abilities to induce antiplasmid activity against E. coli F'lac plasmid. Several phenothiazine derivatives were much more potent in antiplasmid activity than benzo[a]phenothiazine- or benz[c]acridine derivatives. Their antiplasmid activity seemed to be enhanced by Cl- or CF3- substitution at 2 C atom, and modified by the side chain length and charge at the L-region of the molecules, as well as by hydrophilicity.

Acridines↗

PubMedDate not supplied

In vitro antiproliferative effects of tricyclic psychopharmaceutical agents and synergism with some resistance modifiers.

Some of the phenothiazines and dibenz[b,f]azepines exert an antiproliferative effect on HEp-2 and rat prolactinoma cells. The same compounds also have effects on different membrane-bound biochemical events, such as H2O2 formation and the peroxide-generated chemiluminescence of polymorphonuclear leukocytes. The superoxide dismutase inhibition by 7,8-dioxochlorpromazine and 6,9-dioxochlorpromazine have some relation to the growth inhibitory action on the growth of HEP-2 and prolactinoma cells in vitro. The antiproliferative effects of phenothiazines were synergized with resistance modifiers like verapamil, omeprazole and tubulozole-C, due to increased drug-influx or decreased drug-efflux and due to possible action on the cytoskeleton.

Animals↗

PubMedDate not supplied

Cytotoxicity and differentiation-inducing activity of phenothiazine and benzo[a]phenothiazine derivatives.

The effects of 13 phenothiazines, and 8 benzo[a]phenothiazines on the growth and differentiation of various human cultured cell lines were investigated. Perphenazine dimaleate and chlorpromazine hydrochloride were more cytotoxic against human normal fibroblasts and glioma cells than 19 other related compounds. The differentiation of three human myelogenous leukemic cell lines (ML-1, U-937, THP-1) into maturing monocytes/macrophages was potently induced by 12H- benzo[a]phenothiazine and 5-oxo-5H-benzo[a]phenothiazine. The differentiation--inducing activity of phenothiazine, and other benzo[a]phenothiazine derivatives was much less, and that of phenothiazine derivatives without the benzyl group was undetectable. Simultaneous treatment with 12H- benzo[a]phenothiazine and tumor necrosis factor produced additive, but not synergistic differentiation--induction of these cells.

Cell Differentiation↗

PubMedDate not supplied

Phenothiazines and calmodulin (review).

The cytotoxic properties of the phenothiazines suggest the potential of phenothiazines as antitumor drugs. The following are some important characteristics of phenothiazines for antitumor research: (i) Phenothiazines show an inherent cytotoxicity which can be utilized in the treatment of tumors. (ii) Selective concentration of phenothiazines in tissues such as melanoma and brain tumors can be utilized in the treatment of such tumors. (iii). Structural modifications of phenothiazines with the substitution of a nitrogen atom may lead to more potent cytotoxic agents, particularly when used in combination with radiation. (iv) A synergic effect may be achieved when phenothiazines are used in combination with other agents and conditions. (v) More research is required for understanding the molecular mechanisms responsible for the cytotoxicity of phenothiazines. (vi) Phenothiazines seem to show both antitumor as well as anticarcinogenic properties. The latter property may be utilized in preventing the formation of tumors as well as in the treatment of tumors at very early stages of their development.

Adult↗

PubMedDate not supplied

Interaction of chlorpromazine with DNA.

The mechanism of the potential anticancer agent chlorpromazine hydrochloride (CPZ) with DNA was investigated by the techniques of high-performance liquid chromatography (HPLC), viscosity and Raman spectroscopy. It has been suggested from HPLC work that DNA nucleotides (except nucleosides) from either a CPZ-DNA system or a CPZ-nucleotide system. Furthermore, the shear stress of the viscosity of the CPZ-DNA system and the CPZ-nucleotide systems ware shown to be apparently the higher increasing than that of DNA and nucleotide alone. These systems had non-Newtonian properties for the formation of the CPZ-DNA and the CPZ-nucleotide systems under experimental conditions. The Raman spectra showed a dramatic difference at 982 cm-1 due to the symmetric P-O stretching vibration of the PO4(2-) group between dGMP and the CPZ-dGMP system.

Antineoplastic Agents↗

PubMedDate not supplied

Raman spectra of methyl substituted benz[c]acridines and their complex with DNA.

Raman spectra of methyl substituted benz[c]acridines (BAc) in the solid state were recorded. Their assignments were proposed for the frequencies of Raman spectra observed. The purpose of this work was to elucidate the mechanisms of interaction between BAc and DNA in vitro. For the DNA-BAc complex, the data show that BAc interact not only with the bases pair, but also with the sugar-phosphate site of DNA within the interbinding process.

Acridines↗

PubMedDate not supplied

Quantumchemical structure of carcinogenic benz[c]acridines.

Resonance energies, circuit resonance energies and bond currents of benz[c]acridines were calculated by Aihara's IRE theory. Consequently, it was shown that these compounds had very stable aromatic characters with positive resonance energies and that the resonance energies per pi-electron values for the compounds with lack of the double bond corresponding to the K-region from parent skeleton were more stable than those of their parent compounds. Carcinogenic activity of the compounds was related to the charge at QK, QN and QL and high electron density on HOMO orbital.

Acridines↗

PubMedDate not supplied

Effect of benzo[a]phenothiazines on natural killer cell activity of human peripheral blood mononuclear cells.

Four benzo[a]phenothiazines were investigated for their effects on antibody-dependent cellular cytotoxicity (ADCC) and natural killer (NK) cell and blast transformation of human peripheral blood mononuclear cells (PBM). Benzo[a]phenothiazines dose-dependently suppressed the nitrogen-stimulated T cell proliferation. The suppressive effect of non differentiation-inducing benzo[a]phenothiazines was higher than that of differentiation-inducing benzo[a]phenothiazines. The stimulation effect of differentiation-inducing compounds on the NK activity was reduced by removal of monocytes from the PBM. The results suggest the direct activation of monocytes (Mo) by differentiation-inducing benzo[a]phenothiazines.

Antibody-Dependent Cell Cytotoxicity↗

PubMedDate not supplied

Diverse biological activities displayed by phenothiazines, benzo[a]phenothiazines and benz[c]acridins (review).

This review summarizes our experiments which are investigating the relationship between the structure and activity of mainly phenothiazines, benzo[a]phenothiazines and benz[c]acridines. Phenothiazines had potent antiplasmid and antibacterial activities, but induced weak antimicrobial activity in vivo. Their antiplasmid activity seemed to be enhanced by Cl- or CF3- substitution at the 2C position of phenothiazines and modified by the side-chain length and hydrophobicity. Benzo[a]phenothiazines did not show any significant antiplasmid or antibacterial activity, but stimulated the differentiation of human myelogenous leukemic cell lines and natural killing activity of human peripheral blood mononuclear cells in vitro, and induced antimicrobial activity in vivo. Circuit current energy (CRE), circuit current (CC), bond current (BC), diatropic and paratropic properties of benzo[a]phenothiazines might be correlated with their biological activity. Benz[a]acridine showed both in vitro and in vivo antimicrobial activities, and carcinogenic activity for skin tumor. The carcinogenic benz[c]acridines showed out-of-phase in the L-region and their energy was accumulated in the K-region of the molecular orbitals. The results suggest the involvement of different molecular orbitals for the expression of various biological activities by phenothiazines, benzo[a]phenothiazines and benz[c]acridines.

Acridines↗