-
[show abstract]
[hide abstract]
ABSTRACT: Terpinolene is a cyclic monoterpene compound found in some Labiatae herbs. In our previous study, we evaluated the sedative effect of inhaled essential oils of Microtoena patchoulii leaves in mice and isolated terpinolene as an active ingredient. We investigated the structure-activity relationships of terpinolene to identify the structural part essential to its sedative effect. Comparison of terpinolene analog activities showed that a double bond in the side-chain or pi bonds in the six-membered ring play important roles in the sedative effect. In another experiment using olfactory impaired mice, we further revealed that inhaled terpinolene exerted the effect after nasal absorption into the body.
Journal of Natural Medicines 01/2013; · 1.39 Impact Factor
-
Folia Pharmacologica Japonica 08/2012; 140(2):71-5.
-
[show abstract]
[hide abstract]
ABSTRACT: The present study investigated the gastroprotective effects of a cinnamon diet using different gastric ulcer mouse models. Dose dependency and the effective dose period of administration of a cinnamon powder diet were established using the water immersion stress gastric ulcer model. A cinnamon powder diet significantly protected mice against ulceration by stress, ethanol, HCl and oral administration of aspirin, but not against ulceration by oral administration of indomethacin or subcutaneous administration of indomethacin or aspirin. Such a diet conferred protection against gastric ulcers at an effective concentration of 100 mg cinnamon powder per gram of food after administration for 4 weeks and the active compound of cinnamon powder for gastroprotective activity was identified as cinnamaldehyde. These findings indicate that regular ingestion of cinnamon powder offers gastroprotection presumably through a cytoprotective mechanism but the efficacy against NSAIDs-induced gastric ulcers may be limited.
Journal of Natural Medicines 07/2012; · 1.39 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The resinous portions of Aquilaria plants, called agarwood, have been used as medicines and incenses. Agarwood contains a great variety of sesquiterpenes, and a study using cultured cells of Aquilaria crassna showed that the production of sesquiterpenes (α-guaiene, α-humulene, and δ-guaiene) was induced by treatment with methyl jasmonate, which led to the cloning of δ-guaiene synthases. In the present study, analyses of genomic organization and Southern blotting of δ-guaiene synthase in A. crassna were performed in order to examine the genomic background of δ-guaiene synthases in Aquilaria plants. Genomic cloning and sequencing revealed five types of sequence in putative δ-guaiene synthases sharing more than 96% identity in exon regions, and that these enzymes belonged to the class III TPS subfamily with seven exons and six introns. Furthermore, Southern blotting revealed that at least five copies of δ-guaiene synthase existed in A. crassna. The hybridization of digested DNA of A. crassna and A. sinensis with probes made with a δ-guaiene synthase cDNA fragment resulted in different banding patterns for these two species. It may be possible to identify Aquilaria species by restriction fragment length polymorphism analyses with δ-guaiene synthase cDNA probes.
Journal of Natural Medicines 04/2011; 65(3-4):508-13. · 1.39 Impact Factor
-
Michiho Ito
Yakugaku zasshi journal of the Pharmaceutical Society of Japan 03/2011; 131(3):373-4. · 0.39 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Microtoena patchoulii (Labiatae) is a perennial herb that grows in southern China. In the present study, the sedative activity of the essential oil of the leaves was evaluated using mice when the volatile oil was administered by inhalation. The inhalation of the oil by mice significantly reduced the spontaneous motor activity. Fractionation of the oil revealed that the main constituents in the oil were 1-octen-3-ol, terpinolene, patchouli alcohol, and methyl salicylate. Each 1-octen-3-ol, terpinolene, or patchouli alcohol significantly reduce the locomotor activity when it was administered singly. However, the essential oil fraction containing both patchouli alcohol and methyl salicylate did not exhibit any effects. It is suggested that methyl salicylate might negate the sedative effect of patchouli alcohol, and that the concentration ratios of the compounds in vapor would play important roles as sedatives. In order to clarify the mechanism of action, the effects of these compounds on caffeine-induced excitation and pentobarbital-induced elongation of sleeping time in mice were tested. Each 1-octen-3-ol or terpinolene reduced the locomotor activity excited by caffeine to those of normal levels. Elongation of sleeping time induced by pentobarbital was further elongated by the inhalation of terpinolene, but not by that of 1-octen-3-ol. It is indicated that terpinolene is a potent suppressor of the central nervous system.
Journal of Natural Medicines 02/2011; 65(2):336-43. · 1.39 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The resinous portions of Aquilaria plants, called agarwood, have been used as medicines and incenses. Agarwood contains a great variety of sesquiterpenes, and a study using cultured cells of Aquilaria showed the production of sesquiterpenes (α-guaiene, α-humulene, and δ-guaiene) to be induced by treatment with methyl jasmonate (MJ). In this study, the accumulation and production of sesquiterpenes were quantified. The amounts accumulated and produced reached a maximum at 12 h, and the most abundant product was α-humulene at 6 h and δ-guaiene after 12 h. However, a headspace analysis of the cells revealed that α-humulene is likely to be volatilized; so overall, the most abundant sesquiterpene in the cells was δ-guaiene. A cDNA library from RNA isolated from MJ-treated cells was screened using PCR methodologies to isolate five clones with very similar amino acid sequences. These clones were expressed in Escherichia coli, and enzymatic reactions using farnesyl pyrophosphate revealed that three of the clones yielded the same compounds as extracted from MJ-treated cells, the major product being δ-guaiene. These genes and their encoded enzymes are the first sesquiterpene synthases yielding guaiane-type sesquiterpenes as their major products to be reported. Expression of a fourth terpene synthase gene in bacteria resulted in the accumulation of the protein in insoluble forms. Site-directed mutagenesis of the inactive clone and three-dimensional homology modeling suggested that the structure of the N-terminal domain was important in facilitating proper folding of the protein to form a catalytically active structure.
Plant physiology 10/2010; 154(4):1998-2007. · 6.53 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Geraniol and linalool synthases were isolated from three pure strains of Perilla hirtella and Perilla setoyensis, which are wild species of perilla. Their amino acid sequences were very similar to those of Perilla citriodora and Perilla frutescens that were reported previously. However, comparison of the sequences of the same functional synthases derived from different species of Perilla demonstrated that the similarities were high among P. citriodora, P. hirtella and P. frutescens, but low between P. setoyensis and any of the others. This result corresponds well with our previous results showing that P. setoyensis is remotely related to the other perilla species. Both geraniol and linalool synthases utilize geranyl diphosphate (GDP) as their catalytic substrate and they were expressed simultaneously in perilla. The linalool synthase is considered to be the enzyme whose metabolite seems not to be oxidized nor reduced in the plant body and the geraniol and limonene synthases are the initial-step-catalyzing enzymes for a variety of oil compounds. The regulation of the substrate flow between them would be interesting for further study.
Phytochemistry 07/2010; 71(10):1068-75. · 3.35 Impact Factor
-
Michiho Ito
[show abstract]
[hide abstract]
ABSTRACT: The research field of pharmacognosy covers a wide variety of subjects based on a knowledge of natural medicines and extends its influence in all surrounding directions. Pharmacognosy itself is generally regarded as one of the branches of pharmaceutical science although the processes to achieve the objectives are not always analytical as are other branches in this field. The extraordinarily long history and broad view provide researchers opportunities to conduct unique projects which can enhance the perspective of the subject in the future. Fieldwork is one feature of scientific research and is viewed as more valuable to projects in pharmacognosy than to those in other fields of pharmaceutical sciences. The frame of my research has been formed around fieldwork; projects targeted are achieved based on information and samples gathered through this means, and further studies are suggested by the ideas obtained. Some of the results and experiences gathered in these projects are described in this article for discussion of the future image of the pharmacognosial field.
Yakugaku zasshi journal of the Pharmaceutical Society of Japan 05/2010; 130(5):687-95. · 0.39 Impact Factor
-
Michiho Ito
Yakugaku zasshi journal of the Pharmaceutical Society of Japan 05/2010; 130(5):671-2. · 0.39 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Cytochrome P450 mono-oxygenases from peppermint, spearmint and perilla (all members of the family Lamiaceae) mediate the regiospecific hydroxylation of the parent olefin (-)-limonene to produce essential oil components oxygenated at C3, C6 and C7, respectively. Cloning, expression and mutagenesis of cDNAs encoding the peppermint limonene-3-hydroxylase and the spearmint limonene-6-hydroxylase have allowed the identification of a single amino acid residue which determines the regiospecificity of oxygenation by these two enzymes. A hybridization strategy provided a cytochrome P450 limonene hydroxylase cDNA from perilla with which to further evaluate the structural determinants of regiospecificity for oxygenation of the common substrate (-)-limonene. The perilla cDNA was a partial clone of 1550bp (lacking the N-terminal membrane insertion domain), and shared 66% identity with the peppermint 3-hydroxylase and spearmint 6-hydroxylase at the amino acid level. The perilla cytochrome P450 was expressed in Escherichia coli as a chimeric protein fused with the N-terminal membrane insertion domain of the limonene-3-hydroxylase. The kinetically competent recombinant protein was characterized and shown to produce a mixture of C3-, C6- and C7-hydroxylated limonene derivatives with a distribution of 33%, 14% and 53%, respectively.
Phytochemistry 03/2010; 71(4):373-9. · 3.35 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Periodic update of stored seeds is indispensable for sustainable use and preservation of plant genetic resources, and performance of this task requires precise data on the relationship between storage period and the germination rate of seeds after long-term storage. In this study, germination rates of pure strains of perilla (Perilla frutescens (L.) Britton var. crispa) were investigated for three strains by using the mericarps stored for 1-20 years at 4 degrees C under dry conditions. The germination rates were fairly good (65-70%) for 5-8 years after harvest, but dropped to almost 0% for mericarps stored more than 9 years. Mericarps that did not germinate were analyzed for viability by using 2,3,5-triphenyltetrazolium chloride. For old mericarps (stored more than 9 years), the germination rates and seed viability did not correlate. Further study on days required for germination of mericarps harvested each year was derived from our observation record, suggesting that germination rates and longevity of mericarp life were increasingly influenced by individual difference as the storage period lengthened.
Journal of Natural Medicines 03/2010; 64(3):378-82. · 1.39 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Valerena-4,7(11)-diene and beta-maaliene were isolated from spikenard for the first time, and the effects of inhaling these compounds were investigated. Both compounds reduced the locomotor activity of mice dose-dependently, even at a low dose. Valerena-4,7(11)-diene had a particularly profound effect, with the strongest sedative activity observed at a dose of 0.06%. Caffeine-treated mice that showed an area under the curve (AUC) for locomotor activity that was double that of controls were calmed to normal levels by administration of valerena-4,7(11)-diene. The continuous sleep time of pentobarbital-treated mice was prolonged by about 2.7 times with valerena-4,7(11)-diene, an effect similar to that of chlorpromazine administered orally.
Journal of Natural Medicines 06/2009; 63(4):380-5. · 1.39 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Cinnamomi cortex, which is normally referred to as cinnamon, is a very popular spice as well as an important natural medicine. High-quality cinnamon is traditionally believed to taste sweet and be strongly pungent without astringency. Cinnamomi cortex with larger amounts of cinnamaldehyde was sweeter in taste comparisons. The contents of tannins and sugars in cinnamon powder had little effect on the taste. Evaluations of the sweetness and pungency of cinnamaldehyde solutions (0.1, 0.25, 0.50, 0.75, 1.0, and 5.0 mg/ml) were performed using volunteers. The scores for sweetness increased significantly from 0.10 to 0.50 mg/ml (P < 0.05, Mann-Whitney U-test), but there was no significant difference above 0.75 mg/ml. The concentration threshold for the sweet taste of cinnamaldehyde appeared to be less than 0.75 mg/ml, and the more concentrated solutions gave excessive pungency. Therefore, two contrastive tastes of Cinnamomi cortex, sweet and pungent, were both attributed to cinnamaldehyde. Consequently, its taste, one of its indices of quality, seems to vary mainly according to the content of cinnamaldehyde.
Journal of Natural Medicines 03/2009; 63(3):261-6. · 1.39 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The monoterpene D-limonene shows cancer preventative and cancer therapeutic activities in vitro and in vivo. Unlike plants, animals are unable to synthesize limonene de novo and obtain limonene through dietary sources. In the present study we established transgenic mouse embryonic NIH 3T3 fibroblast cells that produce limonene by introducing the D-limonene synthase gene obtained from Japanese catnip (Schizonepeta tenuifolia). Apoptosis was not observed in the limonene-producing cells. A concomitant increase in the level of apoptosis-related protein Bcl-2 (B-cell lymphoma protein 2) and decreases in the levels of Bad (Bcl-2 antagonist of cell death) and phosphorylated JNK (c-Jun N-terminal kinase) were observed in limonene-producing cells. Limonene-producing cells may provide a useful new system to investigate the in vivo function of this monoterpene.
Biotechnology and Applied Biochemistry 07/2008; 52(Pt 3):185-90. · 1.53 Impact Factor
-
Michiho Ito
[show abstract]
[hide abstract]
ABSTRACT: Fieldwork is one of the primary methods for studying medicinal plants and materials, and information thus obtained can be valuable for experiments performed in the laboratory. Meanwhile, results of experiments in the laboratory can be brought back to the field for verification and further investigation. A combination of field and laboratory work has led to effective progress in studies of medicinal plants in the field of pharmacognosy. However, the collection of samples with information through fieldwork is not easy, and it fundamentally requires a great deal of research experience. Geographical, ethnical, and political affairs often affect its performance, and to establish a good cooperative relationship with foreign localities is inevitably required. Beyond these difficulties, fieldwork can provide a framework for the research project and excellent and unique viewpoints concerning the target. This review article describes studies on perilla, agarwood, and cinnamon, focusing mainly on the results of fieldwork performed in Indochina on these species. All three of these medicinal plants contain essential oils, and their composition varieties, biosynthetic pathways, pharmacological activities, or induction mechanisms for production are principally investigated through shuttling between fieldwork and laboratory experiments.
Journal of Natural Medicines 07/2008; 62(4):387-95. · 1.39 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: An ethanol extract of Helichrysum maracandicum showed antiproliferative activity against cultured cells of SENCAR mouse in an in vitro assay, and activity-guided fractionation of the extract resulted in the isolation of isosalipurposide as an active substance. Naringenin chalcone, the aglycone of isosalipurposide, also showed strong antiproliferative activity. An in vivo assay of two-stage carcinogenesis on mouse skin revealed that epidermal application of isosalipurposide resulted in delayed formation of papillomas. Western blot analysis showed that the expression of p38 mitogen-activated protein kinase was suppressed by the administration of naringenin chalcone or isosalipurposide, which might be related to the anticarcinogenic activity.
Journal of Natural Medicines 05/2008; 62(2):174-8. · 1.39 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Twenty-eight samples of mericarps of Perilla frutescens var. frutescens were collected through fieldwork performed in Phongsali and Xieng Khouang provinces in northern Laos. No perilla samples were collected from Savannakhet province in the south although more than 20 sites were investigated. Perilla plants are mostly grown mixed with dry-paddy rice by slash-and-burn cultivation in Laos. The most popular local name for perilla mericarps in the area was "Ma Nga Chan". Weight of 1,000 grains and hardness of the mericarps were measured, and all mericarps were found to be large (weight of 1,000 grains around 2 g) and soft (limit load weight under 300 g), which were preferred for culinary use in Laos. The composition of the essential oils obtained from the herbaceous plants raised from the mericarps was divided into five types, perillaketone, elemicine plus myristicine, shisofuran, piperitenon, and myristicine, and GC-MS analysis of these Laotian perilla samples showed that they were similar to those of corresponding types of known Japanese perilla strains. One of the shisofuran-type perilla contained large amounts of putative alpha-naginatene, which is likely to be an intermediate of the biosynthesis of naginataketone. The farmers' indifference to the oil type of the leaf seems to leave Laotian perilla as a good genetic resource for studies of the biosynthesis of oil compounds.
Journal of Natural Medicines 05/2008; 62(2):251-8. · 1.39 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Agarwood oil and spikenard extract were examined for their sedative activity using a spontaneous vapor administration system. It was shown that inhalation of agarwood oil vapor sedated mice. The main volatile constituents of the oil were found to be benzylacetone [agarwood oil from a Hong Kong market (1)], or alpha-gurjunene and (+)-calarene [agarwood oil made in Vietnam (2)]. A hexane extract of spikenard contained a lot of calarene, and its vapor inhalation had a sedative effect on mice. Individual principles benzylacetone, calarene, and alpha-gurjunene were administered to mice, which reproduced the result of the corresponding oil or extract. However, the most effective dose of the compounds was lower than their original content in the oil and extract (benzylacetone 0.1%, calarene 0.17%, alpha-gurjunene 1.5%).
Journal of Natural Medicines 02/2008; 62(1):41-6. · 1.39 Impact Factor
-
Yoshio Takeda,
Maki Tomonari,
Shihoko Arimoto,
Toshiya Masuda,
Hideaki Otsuka,
Katsuyoshi Matsunami,
Gisho Honda, Michiho Ito,
Yoshihisa Takaishi,
Fumiyuki Kiuchi,
Olimjon K Khodzhimatov,
Ozodbek A Ashurmetov
[show abstract]
[hide abstract]
ABSTRACT: A new phenolic glucoside was isolated from the aerial parts of Origanum tyttanthum, an Uzbek medicinal plant, together with 12 known compounds. The structure of the new compound was elucidated as 4-O-beta-D-glucopyranosylbenzyl-3'-hydroxyl-4'-methoxybenzoate (1) based on the spectral and chemical evidence.
Journal of Natural Medicines 02/2008; 62(1):71-4. · 1.39 Impact Factor
