Recent trends in ginseng research.

Ginseng, the dried root of Panax ginseng, contains ginsenosides and has long been used in Korea, China, and Japan to treat various symptoms. Many studies on the utility of ginseng have been conducted and in this paper we investigate recent trends in ginseng research. P. ginseng studies were collected from scientific databases (PubMed, Web of Science, and SciFindern) using the keywords "Panax ginseng C.A. Meyer", "ginsenosides", "genetic diversity", "biosynthesis", "cultivation", and "pharmacology". We identified 1208 studies up to and including September 2023: 549 studies on pharmacology, 262 studies on chemical components, 131 studies on molecular biology, 58 studies on cultivation, 71 studies on tissue culture, 28 studies on clinical trials, 123 reviews, and 49 studies in other fields. Many researchers focused on the characteristic ginseng component ginsenoside to elucidate the mechanism of ginseng's pharmacological action, the relationship between component patterns and cultivation areas and conditions, and gene expression.

Resultant compound from sublimation test for Gentianae Radix in Japanese Pharmacopoeia was 5-(hydroxymethyl)furfural.

Gentianae Radix, an herbal medicine, has been used as a gastrointestinal drug in Japan. In the Japanese Pharmacopoeia 18th Revision, the sublimation test is specified as an identification test for Gentianae Radix. The compound obtained in this sublimation test was believed to be gentisin, a xanthone family compound. However, the compound we identified using liquid chromatography-high-resolution mass spectrometry (LC-HRMS) and 1H- and 13C-NMR was 5-(hydroxymethyl)furfural (5-HMF). The same compound was found to be a sublimate of Gentianae Scabrae Radix and Gentianae Macrophyllae Radix, belonging to the same genus as Gentianae Radix. These results indicate the necessity to revise the identification test for Gentianae Radix to a more unique method.

Genetic diversity of Panax ginseng cultivated in Japan and its relation with some plant characteristics.

In East Asia, Panax ginseng is one of the most important medicinal plants and has been used in traditional medicines from ancient times. Today, P. ginseng is cultivated in Korea, China, and Japan. Although the genetic diversity of P. ginseng in Korea and China has been reported previously, that of P. ginseng cultivated in Japan is largely unknown. In the present study, genetic diversity of P. ginseng cultivated in Japan was analyzed using eight simple sequence repeat markers that have been used in other studies, and the results were compared with previous results for Korea and China. The correlation between genetic diversity and plant characteristics, such as ginsenoside contents, were also examined. The genetic diversity of P. ginseng in Japan was substantially different from that in Korea and China, probably due to Japan's history of cultivation and the ginseng reproduction system of agamospermy. The genetic analysis indicated that P. ginseng cultivated in Japan could be classified into two clusters. The classification was related to the contents of ginsenosides Re and Ro in the main root but not to the cultivation region of the samples. These results may be useful for the cultivation and quality control of P. ginseng in Japan.

Genetic identification of the original plant species for Mentha Herb listed in the Japanese Pharmacopoeia and analyses of their essential oil composition.

Mentha arvensis Linné var. piperascens Malinvaud is an original plant species for "Mentha Herb (Hakka, ハッカ)" and "Mentha Oil (Hakka-yu, ハッカ)" listed in the Japanese Pharmacopoeia, whereas Mentha canadensis L. is that of "Mint oil, partly dementholised" listed in the European Pharmacopoeia. Although these two species are thought to be taxonomically identical, there are no data on whether the source plants of the Mentha Herb products distributed in the Japanese market are actually M. canadensis L. This is an important issue for international harmonization of the Japanese Pharmacopoeia and European Pharmacopoeia. In this study, 43 Mentha Herb products collected from the Japanese market and two plant samples of the original species of Japanese Mentha Herb harvested in China were identified by sequence analyses of the rpl16 regions in the chloroplast DNA, and the composition of their ether extracts was analyzed by GC-MS. Almost all samples were identified as M. canadensis L., and the main component of their ether extracts was menthol, although there were variations in their composition. However, there were some samples thought to be derived from other Mentha species, even though their main component was menthol. For quality control of Mentha Herb, it is important to be sure of not only the original plant species but also the composition of the essential oil and amount of menthol as the characteristic compound.

Investigation of microsatellite loci for the identification of registered varieties of Perilla frutescens and a discussion on the ancestor species of P. frutescens.

Techniques for identifying varieties of crops used as spices and food additives have important implications for the safety of food production, prevention of false labeling, protection of breeders' rights, and prevention of theft or outflow to other countries. Presently, there are 16 varieties of Perilla frutescens in the variety registration system of the Ministry of Agriculture, Forestry and Fishes in Japan (Ministry of Agriculture, Forestry and Fisheries. Variety registration data search. http://www.hinshu2.maff.go.jp/ . Accessed 03 Nov 2022). One such variety is "Shimoadachi," which contains citral as a main essential oil component and has a lemon-like smell. To our knowledge, no other cultivars with similar characteristics in P. frutescens have been identified. Additionally, the registered variety "per-001" contains high contents of perillaldehyde and rosmarinic acid, with practical applications for herbal medicines and functional foods. Therefore, the development of variety identification techniques is necessary for stable production and protection. In this study, we investigated microsatellite loci for the accurate identification of registered varieties of red perilla. These loci provide a basis for breeding superior varieties of medicinal plants.

Molecular Descriptors and QSAR Models for Sedative Activity of Sesquiterpenes Administered to Mice via Inhalation.

Essential oils are often utilized for therapeutic purposes and are composed of complex structural molecules, including sesquiterpenes, with high molecular weight and potential for stereochemistry. A detailed study on the properties of selected sesquiterpenes was conducted as part of a broader investigation on the effects of sesquiterpenes on the central nervous system. A set of 18 sesquiterpenes, rigorously selected from an original list of 114, was divided into 2 groups i.e., the training and test sets, with each containing 9 compounds. The training set was evaluated for the sedative activity in mice through inhalation, and all compounds were sedatives at any dose in the range of 4 × 10-4-4 × 10-2 mg/cage, except for curzerene. Molecular determinants of the sedative activities of sesquiterpenes were evaluated using quantitative structure-activity relationship (QSAR) and structure-activity relationship (SAR) analyses. An additional test set of six compounds obtained from the literature was utilized for validating the QSAR model. The parental carbonyl cation and an oxygen-containing groups are possible determinants of sedative activity. The QSAR study using multiple regression models could reasonably predict the sedative activity of sesquiterpenes with statistical parameters such as the correlation coefficient r2 = 0.82 > 0.6 and q2 LOO = 0.71 > 0.5 obtained using the leave-one-out cross-validation technique. Molar refractivity and the number of hydrogen bond acceptors were statistically important in predicting the activities. The present study could help predict the sedative activity of additional sesquiterpenes, thus accelerating the process of drug development.

Preparation and pharmaceutical properties of Hangeshashinto oral ointment and its safety and efficacy in Syrian hamsters with 5-fluorouracil-induced oral mucositis.

Chemotherapy-induced oral mucositis (COM) is a common adverse effect of cancer chemotherapy. Several clinical studies reported that repetitive use of mouthwashes containing 2.5-6.25% Hangeshashinto (HST), a Kampo formula, relieves COM, but the effect is insufficient. To solve this problem, we produced an oral ointment of 12% HST extract (considered quantitatively equivalent to 20% commercially available HST), which will increase the local concentrations of its active ingredients and prolong the contact time with COM. In this study, we evaluated the pharmaceutical properties (spreadability and stability) of HST oral ointment. In addition, its safety (oral mucosal irritation) and therapeutic effects on 5-fluorouracil-induced oral mucositis were evaluated in male Syrian hamsters. The HST ointment showed good spreadability and stability for more than 8 weeks at 4 °C. In the oral mucosal irritation test, topical application of HST ointment (0.2 g) three times per day for 14 days had no adverse effect on the oral mucosa of hamsters. In hamsters treated with 5-fluorouracil (60 mg/kg) twice, COM was induced by a submucosal injection of 5% acetic acid into the cheek pouch. When HST ointment (50 µg) was topically applied to the mucositis area once per day for 12 days, the area and macroscopic score of mucositis were significantly decreased, and the depth of the wound tended to be reduced compared with the lactose ointment-treated control animals. These findings suggest that HST oral ointment shows good properties in spreadability, stability, and safety, and elicits a therapeutic effect in an animal model of COM.

Content and distribution of prunasin in Perilla frutescens.

Perilla frutescens var. crispa (Lamiaceae) is an annual plant that is the botanical origin of the natural medicine "Soyo" listed in the Japanese Pharmacopoeia and is also used as a fragrant vegetable. Its characteristic components are essential oils and anthocyanins. Cyanogenic glycosides have also been isolated from perilla, but no reports have clarified which cyanogenic glycosides are abundant or differences in cyanogenic glycoside content according to the extent of perilla leaf growth or growth stage. Here, for the first time we determined the content and distributions of cyanogenic glycosides in perilla. The picric acid test, a common qualitative test for cyanogenic compounds, was used to quickly and semi-quantitatively detect cyanogenic compounds in perilla. Prunasin was the most abundant cyanogenic glycoside. The prunasin content per unit mass of perilla leaves varied by strain, regardless of leaf color or the main compound in the essential oils of each strain. Prunasin was higher in fresh leaves than in dried leaves and higher in young leaves than in mature leaves. When perilla was cultivated in an outdoor field, the prunasin content was initially high during the vegetative stage in summer before decreasing and then increasing until flower buds were beginning to form, and then gradually decreased again after flowering.

Agarotetrol as an index for evaluating agarwood in crude drug products.

Agarotetrol in agarwood has been detected in water extracts or decoctions from medical use agarwood but the detection of agarotetrol has not been reported from other crude drugs. Agarwood generates the sedative benzylacetone upon heating. In this study, crude drug products containing many kinds of crude drugs in addition to agarwood were analyzed. Agarotetrol was detected and quantified, demonstrating that agarotetrol is useful for the quality evaluation of agarwood in complex prescriptions. High-performance liquid chromatography conditions to clearly separate agarotetrol from crude drug products were established and agarotetrol from Kampo decoctions was detected and quantified. Agarotetrol was also detected even from small crude drug product samples. These results suggest that agarotetrol is a useful component for the quality evaluation of agarwood in crude drug products.

Comparison of phenolic compounds contained in Aquilaria leaves of different species.

Leaves of Aquilaria plants contain a variety of phenolic compounds such as iriflophenone glycosides, mangiferin, and genkwanin. Previous studies showed that Aquilaria leaf extracts exhibit many pharmacological activities, including antidiabetic and laxative effects. However, a few studies have reported differences in the chemical content and compositions of Aquilaria species. Here, three Aquilaria species were identified using matK and trnL-trnF sequences and their leaves were analyzed by HPLC and LC/MS. Comparison of the chemical components and α-glucosidase inhibition activity of the three species showed that the level of iriflophenone glycosides in A. rugosa was higher than in A. sinensis and A. crassna. There was no difference in the α-glucosidase inhibition activity of leaf extracts of the three species, but the strength of the inhibition activity can possibly be explained by the total sum of active compounds in the leaf extracts.

Shorter and more efficient pretreatment for germination of perilla mericarps.

Perilla (Perilla frutescens (L.) Britton) mericarps are known to undergo dormancy; however, this can be broken by sulfuric acid treatment and cold stratification. Cold stratification is thought to be the most effective treatment and is customarily performed for 2 weeks to induce germination of perilla mericarps. However, this procedure requires an additional 2 weeks before sowing and cultivation, thereby decreasing cultivation efficiency. To address this problem, germination experiments were conducted in this study in order to identify a shorter and more efficient pretreatment strategy for germination of perilla mericarps. Pretreatment with sulfuric acid (10 min versus 1 min) and gibberellin (8 h and 1 h versus 5 min, at a rate of 100 versus 10 ppm) were performed using mericarps from pure strains of perilla. As a result, sulfuric acid treatment tended to reduce the germination rate, while gibberellin treatment resulted in an equivalent or similar germination rate as cold stratification. Gibberellin treatment was also found to be effective in mericarps with a relatively old harvest date and low germination energy. Considering the convenience and safety of the treatment process as well as the results of the germination experiments, these findings suggest that a short period of gibberellin treatment could help shorten the process of perilla cultivation.

Diversity in principal constituents of plants with a lemony scent and the predominance of citral.

In this study, we extracted essential oils from four species of plants with lemony scents (Melissa officinalis L., Aloysia citriodora Palau (= Lippia citriodora (Palau) Kunth), Thymus × citriodorus, Perilla citriodora (Makino) Nakai). We then examined the components of extracts using gas chromatography (GC) and GC-mass spectrometry (GC-MS). A comparison of components indicated that the largest proportions of essential oils were caryophyllene (25%) in M. officinalis, geraniol (50%) in T. citriodorus, and citral (61 and 82%) in A. citriodora and P. citriodora. Moreover, we used a sensory evaluation method using dilute aqueous solutions of extract components, citral, linalool, d-limonene, and geraniol, to select the mixture with a flavor that mostly resembled lemon. The participants in the study felt that an aqueous citral solution flavored more like lemon than aqueous d-limonene. Furthermore, an open field study of sedative effects of citral and d-limonene, when inhaled, on mice demonstrated that citral exhibited a sedative effect at a lower concentration than that of d-limonene.

Essential oils from Melia azedarach L. (Meliaceae) leaves: chemical variability upon environmental factors.

The chemical composition of the essential oils extracted from the leaves of Melia azedarach L. collected monthly from July 2019 to June 2020 was examined via gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) techniques. Analysis of the essential oils identified about 17 compounds representing more than 85% of the oil. Oil yields were higher in the months of June and August, and the primary compounds identified were ß-caryophyllene (3.50-63.41%), benzaldehyde (3.50-55.98%), and azulene (1.27-19.05%). A correlation analysis was performed to determine the relationship between yields and climatic conditions, and between constituent concentration and temperature and precipitation values during the study period. As per our findings, although not significant, a positive correlation was determined between yield and climatic parameters. However, the oil components were categorized into four groups based on their correlation with temperature and precipitation indices. Among the major components of the essential oils, only azulene and ß-caryophyllene exhibited a negative correlation with both precipitation and temperature. The results show substantial differences in the chemical composition of M. azedarach essential oils and provide further insight into the phytochemical constituents that are sensitive to climate fluctuations. Furthermore, it provides an indication of the optimal time that the plant produces the important mono- and sesquiterpene components and the biological significance of their regulation.

Factors affecting 2-(2-phenylethyl)chromones in artificial agarwood.

Recently, "artificial agarwood" manufactured by the artificial treatment on cultivated agarwood trees is popular in agarwood-producing countries. Although there are various treatment methods, they are not standardized. Moreover, factors that may affect the generated chemical compounds have not been investigated. In this research, the effects of different treatment methods and individual differences on the quantities and types of 2-(2-phenylethyl)chromone in agarwood were investigated to experimentally produce artificial agarwood using Aquilaria sinensis. Each solvent-extracted agarwood sample was analyzed using Liquid Chromatography/Tandem Mass Spectrometry (LC-MS/MS), and peaks were identified by comparing ten types of 2-(2-phenylethyl)chromone with reference standards. The composition and 2-(2-phenylethyl)chromone content of each agarwood sample were observed based on the type of chemical compound, and results indicated that when the treatment method was different, the accumulation pattern of the 2-(2-phenylethyl)chromones differed even when the number of resinification years was the same. Furthermore, the findings of this study showed that additional treatment on a single branch produced more 2-(2-phenylethyl)chromones. Moreover, market products composed of artificial agarwood pieces derived from different tree species and collected from different location were analyzed.

Individual and Combined Inhalational Sedative Effects in Mice of Low Molecular Weight Aromatic Compounds Found in Agarwood Aroma.

Agarwood is known to have a sedative effect and the less studied volatile aromatic constituents it contains may have contribution to the activity. In this study, two Kyara grade (highest-grade agarwood in Japan) samples were extracted using headspace-solid phase microextraction (HS-SPME) and analyzed through gas chromatography-mass spectrometry (GC-MS). Six low molecular weight aromatic compounds (LACs) and one structurally simple compound (diethylene glycol monoethyl ether) present in the aromas were individually evaluated for inhalational sedative activity in mice through open field test. Doses of 0.0001 g/L to 1 g/L were prepared for each compound and administered to mice (n = 6/dose/compound). Results revealed all compounds decreased spontaneous motor activity at almost all doses. Strongest sedative activity of each compound reduced total spontaneous motor activity by more than half against control, demonstrating their contribution to agarwood aroma and potential as independent sedating agents. Mixtures of compounds using their most effective dose were made and evaluated again for inhalational sedative effect. Interestingly, the combination of all compounds showed no significant effect and even caused stimulation in mice movements. This result suggests antagonistic-like interaction between the compounds, which is probably due to structural similarities. Consequently, it implies the other constituents present in agarwood, along with LACs, are also important to the overall sedative activity.

Quantitative Analysis of Ent-Kaurane Diterpenoids in Isodon Herb (Enmei-So) by HPLC-UV.

The terrestrial plants, Isodon japonicus (Burm. f.) H. Hara and Isodon trichocarpus (Maxim.) Kudô (Labiatae), are native to Japan. Different parts of these plants have been used as a traditional bitter stomachic, under the name Isodon herb (Enmei-so). Ent-kaurane diterpenoids are the major constituents of Isodon herb that contribute to the herb's medicinal properties. However, large variability with respect to the composition of these diterpenoids limits the suitability of Isodon herb as a pharmaceutical ingredient. Thus, an investigation of the factors that affect its chemical composition is required. In this study, the DNA-barcoding method, using internal transcribed spacer sequences of nuclear ribosomal DNA, was applied to cultivated and commercial samples of Isodon herb. Further, each such sample was separated into leaves, stems, and flowers and analyzed for diterpenoid content by HPLC. Moreover, the diterpenoid content in coarsely cut and powdered samples was evaluated. Results confirmed that the source species of these samples was I. japonicus or I. trichocarpus. The three major diterpenoids in Isodon herb were enmein, oridonin, and ponicidin. The diterpenoid content was affected by milling process. Moreover, the diterpenoid content was greatly affected by the ratio between leaves and stems in each sample. Thus, to accurately quantify the diterpenoids in Isodon herb, the use specific conditions such as drying using mild temperature conditions and avoiding milling of the samples might be necessary. This may help in regulating variations in the herb's composition, in turn, providing better quality and a safe herbal product for pharmaceutical use.

Cloning of the cytochrome P450 enzyme from Perilla frutescens involved in nothoapiole biosynthesis.

Phenylpropanoid volatile components are found in various plants and are useful in medicines, health foods, and fragrances. While the pharmacological actions and toxicities of these compounds have been investigated, there are few reports of the cloning of genes that encode biosynthetic enzymes involved in substituent formation at diverse positions and numbers. Previously, using the expressed sequence tag (EST) libraries of pure perilla strains that have been maintained for over 30 years for their oil type, we characterized the P450 enzyme that produces an intermediate for dillapiole by adding a hydroxy group to myristicin. In this study, we selected a P450 enzyme involved in nothoapiole biosynthesis from the EST library. Heterologous expression of this enzyme in yeast showed that it is a hydroxylase that synthesizes an intermediate to produce nothoapiole from apiole and dillapiole. The enzyme has high amino acid sequence similarity with a previously cloned enzyme and is categorized into the CYP71D subfamily. Furthermore, we investigated the presence or absence of essential oil components and intermediates believed to be involved in nothoapiole biosynthesis by component analysis of perilla essential oil using GC-MS to help elucidate the biosynthetic pathway of nothoapiole. Only a small number of plant species contain nothoapiole as their principal component and thus few studies have reported the biosynthetic genes involved or the drug efficacy and toxicity of nothoapiole. The present study will aid in understanding the biosynthesis of phenylpropanoid volatile compounds, thereby contributing to further research on potentially useful compounds such as nothoapiole.

Sedative effects of inhaled Perilla frutescens essential oils on mice.

Perilla frutescens is an ingredient for cooking and for Japanese traditional medicine formulations. Essential oils extracted from P. frutescens are classified according to their composition, which are genetically regulated. Here, we extracted five types of essential oil from P. frutescens and studied their sedative activities. We grew P. frutescens strains that give oils of type PK, PA, PP, EK, and C, and extracted the essential oils by hydrodistillation. We then measured the spontaneous locomotor activity of mice who had inhaled the oils in an open field test. All types of essential oil except the PK type decreased the spontaneous locomotor activity of mice. The effective doses were 4.0 × 10-3 to 4.0 × 10-2 mg/cage (PA type), 4.0 × 10-4 mg/cage (PP type), 4.0 × 10-5 mg/cage (EK type), and 4.0 × 10-5 to 4.0 × 10-3 mg/cage (C type). Our results show that the essential oils of type PA, PP, EK, and C have a sedative effect.