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Biomedical subjects

M Iinuma

Publications and source records attributed to M Iinuma.

At least 55 records · Page 3Linked to original sources
PubMed1995

Studies of cuticle drugs from natural sources. III. Inhibitory effect of Myrica rubra on melanin biosynthesis.

The inhibitory effect of a 50% ethanolic extract obtained from the dried leaves and the bark of Myrica rubra, was investigated in vitro on melanin biosynthesis which is closely related to hyperpigmentation. These extracts inhibited tyrosinase activity which converts dopa to dopachrome in the biosynthetic process. Furthermore, the extracts inhibited the production of melanin from dopachrome by autoxidation and also showed superoxide dismutase (SOD)-like activity. After bioassay-guided fractionation, quercetin, myricetin and myricetin 3-O-rhamnoside were isolated from the leaves. As they showed the inhibitory effect on tyrosinase activity, the activity is partially attributable to them in the extract of M. rubra. These results suggested that the leaves or the bark of M. rubra might be used as a whitening agent for the skin.

Melanins↗
PubMed1995

Study on anti-cataract drugs from natural sources. II. Effects of buddlejae flos on in vitro aldose reductase activity.

The inhibitory effects of nine crude drugs were tested on unpurified rat lens aldose reductase, an enzyme involved in the complications of diabetes. Among the crude drugs, a 70% methanolic extract of Buddlejae Flos (flower of Buddleja officinalis) exhibited the highest inhibition. Luteolin, luteolin-7-O-beta-D-glucopyranoside, apigenin and acacetin-7-O-alpha-L-rhamnopyranosyl-(6-1)-beta-D-glucopyranoside isolated from Buddlejae Flos showed the inhibitory activity, the IC50 (concentration of 50% inhibitory percentage) values of which were 0.21, 0.28, 0.58 and 0.75 microM, respectively. It is suggested that the inhibitory effect of Buddlejae Flos on aldose reductase is partially attributable to these flavonols or their glycosides.

Aldehyde Reductase↗
PubMed1994

Inhibition of the growth of cariogenic bacteria in vitro by plant flavanones.

Phytoalexins, defensive compounds produced by plants against microbial infections, were purified from Sophora exigua (Leguminosae) and their growth inhibitory effects on oral cariogenic bacteria were determined in vitro. Among three isolated compounds, 5,7,2',4'-tetrahydroxy-8-lavandulylflavanone completely inhibited the growth of oral bacteria including primary cariogenic mutans streptococci, other oral streptococci, actinomycetes, and lactobacilli, at concentrations of 1.56 to 6.25 micrograms/ml.

Actinomyces↗
PubMed1994

A role of periodontal sensation in development of rhythmical chewing in dogs.

The sucking period of puppies was prolonged by 7 days and the start of rhythmical chewing was delayed to more than 50 postnatal days. In puppies having erupted teeth but no periodontal sensation due to nerve degeneration, chewing rhythm formation was delayed by 20 days. The rhythm of chewing was not affected by extraction of all primary teeth after rhythmical chewing had completed. These results suggest that afferent impulses from the periodontal mechanoreceptors play a role in the chewing rhythm formation at transition from sucking to chewing behavior in new born puppies.

Animals↗
PubMed1994

Anti-oral microbial activity of isoflavonoids in root bark of Ormosia monosperma.

From the root bark of Ormosia monosperma, 10 isoflavonoids including two new compounds 7,4'-dihydroxy-6",6"-dimethylpyrano-(2",3":5,6)-8-(3-methyl-1,3- butadienyl)isoflavone, named ormosidin, and dalbergion 4'-O-beta-D-glucopyranoside, were isolated. These structures were confirmed by spectroscopic analysis. 2,3-Dihydroauriculatin, one of the compounds isolated, showed moderate activities against oral-microbial organisms (Streptococcus mutans, Prophyromonas gingivalis and Actinomyces actinomycetemcomitans).

Anti-Infective Agents↗
PubMed1994

Flavanones with potent antibacterial activity against methicillin-resistant Staphylococcus aureus.

With the therapeutic concept of using the defensive ability of plants against microbial infections, phytoalexin, an antimicrobial phytochemical was studied for its ability to inhibit the growth of methicillin-resistant Staphylococcus aureus (MRSA). Extracts from Sophora exigua (Leguminosae) were fractionated by serial chromatography and the anti-MRSA activity of each fraction was determined by the agar-plate method. Among the active isolates, 5,7,2',6'-tetrahydroxy-6-isoprenyl-8-lavandulyl-4'-methox yflavanone (exiguaflavanone D) completely inhibited the growth of all the MRSA strains examined at the concentration of 1.56-6.25 micrograms mL-1, and 5, 2',6'-trihydroxy-8-lavandulyl-7-methoxy-flavanone (exiguaflavanone B) inhibited at a concentration of 50 micrograms mL-1. This former compound is expected to be a phytotherapeutic agent for MRSA infections as an alternative to conventional antibiotics with unwanted side-effects or the appearance of antibiotic-resistant bacteria.

Anti-Bacterial Agents↗
PubMed1994

Anti-Candida activity of synthetic hydroxychalcones.

The antifungal activity of different synthetic hydroxychalcones was determined against Candida species. It was revealed that the presence of hydroxyl groups at C-2, C-4, and C-2' in chalcone was essential to inhibit Candida growth. Among the chalcone derivatives examined, 2,4,2'-trihydroxy-5'-methylchalcone showed the most intensive anti-Candida activity, suggesting that it could be a potential therapeutic agent for candidosis.

Antifungal Agents↗
PubMed1993

The phenytoin metabolite p-HPPH upregulates prostaglandin biosynthesis in human gingival fibroblasts challenged to interleukin-1.

The effects of and interactions between the major phenytoin (PHT) metabolite 5-parahydroxyphenyl-5-phenylhydantoin (p-HPPH) and interleukin-1 (IL-1 alpha, IL-1 beta) or tumor necrosis factor alpha (TNF alpha) on prostaglandin biosynthesis in human gingival fibroblasts were studied. IL-1 alpha, IL-1 beta and TNF alpha, dose-dependently, stimulated PGE2 formation in gingival fibroblasts. The metabolite, p-HPPH (1.2-2.4 micrograms/ml), did not induce PGE2 formation itself but potentiated IL-1 alpha and IL1 beta induced PGE2 formation in the gingival fibroblasts in a manner dependent on the concentration of both IL-1 and p-HPPH. The metabolite also stimulated IL-1 induced formation of 6-Keto PGF1 alpha, the stable breakdown product of PGI2, in a dose dependent manner. IL-1 beta induces release of [3H]-arachidonic acid ([3H]-AA) from prelabelled fibroblasts, which was potentiated by p-HPPH (> or = 1.2 micrograms/ml). TNF alpha (> or = 1 ng/ml) significantly stimulated the biosynthesis of PGE2 by a process that was also potentiated by p-HPPH. Addition of exogenous, unlabelled AA (10 microM) caused an increase of PGE2 formation in the fibroblasts that was not potentiated by p-HPPH (1.6 micrograms/ml). The results indicate that treatment with p-HPPH results in upregulation of prostaglandin synthesis in gingival fibroblasts challenged to IL-1 or TNF alpha at the level of phospholipase A2.

Cells, Cultured↗
PubMed1993

Epidermal growth factor potentiates interleukin 1 and tumor necrosis factor-induced prostaglandin biosynthesis in human gingival fibroblasts.

The effects of and interactions between epidermal growth factor (EGF), transforming growth factor alpha (TGF-alpha) interleukin 1 (IL-1) and tumour necrosis factor alpha (TNF-alpha) on arachidonic acid release and prostaglandin biosynthesis in human gingival fibroblasts were studied. IL-1 alpha, IL-1 beta and TNF-alpha, but not EGF nor TGF-alpha, stimulated prostaglandin E2 (PGE2) formation in the gingival fibroblasts. The effect of IL-1 alpha, IL-1 beta and TNF-alpha on PGE2 formation was significantly potentiated by EGF in a dose-dependent manner. Similarly, TGF-alpha synergistically potentiated IL-1 beta stimulated PGE2 formation. IL-1 beta but not EGF stimulated the release of 3H-arachidonic acid (3H-AA) from prelabelled gingival fibroblasts. In contrast to the effect on PGE2 formation, no synergistic interaction between EGF and IL-1 was seen on arachidonic acid (AA) release. Addition of unlabelled exogenous AA, in the presence of EGF, resulted in a significant increase in PGE2 formation compared to that seen in fibroblasts not exposed to EGF. The results demonstrate that EGF and IL-1 as well as EGF and TNF-alpha act in concert to enhance prostanoid formation in gingival fibroblasts. Data indicates that EGF potentiates the IL-1 and TNF-alpha induced PGE2 formation at the level of prostaglandin endoperoxide synthase (cyclooxygenase). The synergistic effects of inflammatory cytokines and growth factors may be of physiological importance for regulation of regenerative tissue growth during inflammation and repair.

6-Ketoprostaglandin F1 alpha↗
PubMed1992

Two flavonol glycosides from Vancouveria hexandra.

In addition to two known glycosides, ikarisoside F and epimedin A, two new glycosides of a flavonol with a gamma, gamma-dimethylallyl group were isolated from the underground and the aerial parts of Vancouveria hexandra. The structures were determined to be des-O-methylanhydroicaritin 3,7-diglucoside and anhydroicaritin 3-glucosyl (1----3)rhamnoside-7-glucoside by means of spectral analysis.

Carbohydrate Sequence↗
PubMed1992

Four flavonol glycosides from Achlys triphylla.

Four new flavonol glycosides were isolated from the underground parts of Achlys triphylla in addition to eight known compounds. By means of spectroscopic analysis, the structures were characterized as isorhamnetin 3-glucosyl(1----3)galactoside, isorhamnetin 3-[6''acetylglucosyl(1----3)galactoside], isorhamnetin 3-[4''6''-di-acetylglucosyl(1----3)galactoside], and syringetin 3-[6''-acetylglucosyl(1----3)galactoside], respectively. In the aerial parts of the plant, seven known compounds were also confirmed.

Carbohydrate Sequence↗
PubMed1992

Flavonol glycoside production in callus cultures of Epimedium diphyllum.

Callus cultures of Epimedium diphyllum produced a large amount of epimedoside A in addition to a small amount of diphylloside B, ikarisoside C, epimedoside E, diglycosides of des-O-methylanhydroicaritin (8-gamma, gamma-dimethylallylkaempfero). Icariin, epimedins A-C, which are glycosides of anhydroicaritin, were also produced in the callus cultures. Contents of the flavonol glycosides in callus tissue were higher than those of mother plants, but the composition of each flavonol glycoside mixture in the callus cultures was different from that of the original plants. The time-course experiments showed that an inverse relationship existed between cell growth and flavonol glycoside production. Effects of hormonal factors on cell growth and flavonol glycoside production indicated that 2,4-dichlorophenoxyacetic acid was needed for the production of flavonol glycosides.

Carbohydrate Sequence↗
PubMed1992

Phenytoin potentiates interleukin-1-induced prostaglandin biosynthesis in human gingival fibroblasts.

1. The effect of phenytoin (PHT) on prostaglandin E2 (PGE2) biosynthesis in human gingival fibroblasts stimulated by interleukin-1 (IL-1 alpha, IL-1 beta) or by tumour necrosis factor alpha (TNF alpha) was studied. 2. IL-1 alpha (1.5-6.0 ng ml-1) and IL-1 beta (30-300 pg ml-1), dose-dependently, stimulated PGE2 formation, in 24 h cultures, with IL-beta being the most potent agonist. 3. PHT (2.5-20 micrograms ml-1) did not induce PGE2 formation itself but potentiated IL-1 alpha- and IL-1 beta-induced PGE2 formation in the gingival fibroblasts in a manner dependent on the concentrations of both IL-1 and PHT. 4. IL-1 beta (0.1-1.0 ng ml-1) induced release of [3H]-arachidonic acid ([3H]-AA) from prelabelled fibroblasts that was potentiated by PHT (20 micrograms ml-1). 5. TNF-alpha (greater than or equal to 0.01 micrograms ml-1) significantly stimulated the biosynthesis of PGE2 by a process that was potentiated by PHT. 6. Addition of exogenous arachidonic acid (AA) (greater than or equal to 1 microM) caused an increase of PGE2 formation in the fibroblasts that was not potentiated by PHT (20 micrograms ml-1). 7. The results indicate that treatment with PHT results in upregulation of prostaglandin biosynthesis in gingival fibroblasts challenged with IL-1 or TNF alpha, at least partly due to enhanced level of phospholipase A2 activity.

Arachidonic Acid↗
PubMed1992

Phenolic constituents in Erythrina x bidwilli and their activity against oral microbial organisms.

Five flavonoid compounds, including two new isoflavanones, were isolated from the root bark of Erythrina x bidwilli. Their structures were determined to be 2,10-di(gamma,gamma-dimethylallyl)-3,9-dihydroxypterocarpan (erythrabyssin II), 6,8-di(gamma,gamma-dimethylallyl)-7,2',4'-trihydroxyisoflavanone (bidwillon A), 8-gamma,gamma-dimethylallyl-2',4'-dihydroxy-[6",6"-di-methylpyrano - (2",3":7,6)]isoflavanone (bidwillon B), 8-gamma,gamma-dimethylallyl-7,4'-dihydroxyisoflavone (8-gamma,gamma-dimethyl-allyldaidzein), and 8-gamma,gamma-dimethylallyl-5,2',4'-trihydroxy-[6",6"-dimethylpyrano+ ++- (2",3":7,6)]isoflavone (auriculatin), by means of spectroscopic analysis. Some potent activities against oral microbial organisms (Fusobacterium nucleatum and Prevotella intermedia) were shown in these flavonoid compounds.

Anti-Bacterial Agents↗
PubMed1992

Studies on inhibitors of skin tumor promotion. XI. Inhibitory effects of flavonoids from Scutellaria baicalensis on Epstein-Barr virus activation and their anti-tumor-promoting activities.

To search for possible anti-tumor-promoters, fourteen flavones obtained from the root of Scutellaria baicalensis were examined for their inhibitory effects on the Epstein-Barr virus early antigen (EBV-EA) activation by a short-term in vitro assay. Among these flavones, 5,7,2'-trihydroxy- and 5,7,2',3'-tetrahydroxyflavone showed remarkable inhibitory effects on the EBV-EA activation, and the effect of the latter on Raji cell cycle was also examined by flow cytometer. These two flavones exhibited remarkable inhibitory effects on mouse skin tumor promotion in an in vivo two-stage carcinogenesis test.

Animals↗
PubMed1991

Two flavonol glycosides, hexandrasides C and D, from the underground parts of Vancouveria hexandra.

In addition to four known glycosides, icariin, epimedin B, epimedosides A and E, two new glycosides of a flavonol with a gamma,gamma-dimethylallyl group were isolated from the underground parts of Vancouveria hexandra. The structures were determined to be des-O-methyl-anhydroicaritin 3-O-beta-D-xylopyranosyl(1----2)-alpha-L-rhamnopyranoside 7-O-beta-D-glucopyranosyl(1----2)-beta-D-glucopyranoside and anhydroicaritin 3-O-alpha-L-rhamnopyranosyl(1----3)-alpha-L-rhamnopyranoside 7-O-beta-D-glucopyranoside by means of spectral analysis.

Carbohydrate Sequence↗
PubMed1991

Development of masticatory muscles and oral behavior from suckling to chewing in dogs.

1. At the age of 20 postnatal days, more than a half of the dogs (13/20) showed incisor eruption. At the age of 25 postnatal days, half of the dogs (10/20) showed molar eruption. 2. At the age of 24 postnatal days, half of the dogs (10/20) started chewing behavior. 3. EMG amplitudes of temporal muscle were larger than that of masseter muscle until 26.5 days after birth, but they were reversed at 26.5 days after birth. 4. This suggests that in dogs the earlier teeth erupted, the earlier the dominant oral behavior was changed from suckling to mastication, and concomitantly the dominant muscle for the oral behavior was changed from the temporal to the masseter muscle.

Animals↗