Chemical composition and nematicidal activity of essential oil of Agastache rugosa against Meloidogyne incognita

Nematicidal Activity of Volatiles against the Rice Root-Knot Nematode and Environmental Safety in Comparison to Traditional Nematicides

The rice root-knot nematode (RRKN), Meloidogyne graminicola Golden and Birchfield 1965, is a dangerous crop pest that affects rice production on a global scale. The largest rice-producing countries struggle with the impacts of RRKN infestation, namely, underdeveloped plants and a reduction in rice grain that can reach up to 70% of crop yield. In addition, the shift to strategies of sustainable pest management is leading to a withdrawal of some of the most effective pesticides, given the dangers they pose to the environment and human health. Volatile metabolites produced by plants can offer safer alternatives. The present study characterized the nematicidal activity of volatile phytochemicals against the RRKN and compared the most active with commercial nematicides concerning their safety to the environment and human health. Rice plants were used to grow large numbers of RRKNs for direct-contact bioassays. Mortality induced by the volatiles was followed for four days on RRKN second-stage juveniles. Of the 18 volatiles tested, carvacrol, eugenol, geraniol, and methyl salicylate showed the highest mortalities (100%) and were compared to traditional nematicides using (eco)toxicological parameters reported on freely available databases. While methyl salicylate had a faster activity, carvacrol had more lasting effects. When compared to synthetic nematicides, these volatile phytochemicals were reported to have higher thresholds of toxicity and beneficial ecotoxicological parameters. Ultimately, finding safer alternatives to traditional pesticides can lower the use of damaging chemicals in farming and leverage the transition to agricultural practices with a lower impact on biodiversity.

Agastache Species (Lamiaceae) as a Valuable Source of Volatile Compounds: GC-MS Profiling and Investigation of In Vitro Antibacterial and Cytotoxic Activities

Nowadays, there is an increasing interest in the study of medicinal and aromatic plants, due to their therapeutic properties that correlate with the presence of different active compounds. Agastache species (sp.) are aromatic plants that belong to the Lamiaceae family, originating from North America and East Asia. The present study aimed to evaluate the composition of essential oils (EOs) obtained from different Romanian cultivated Agastache sp. and to investigate their antibacterial and cytotoxic activities. The gas chromatography-mass spectrometry (GC-MS) screening revealed that menthone was the dominant constituent of A. foeniculum (31.58%), A. rugosa (39.60%) and A. rugosa 'After Eight' (39.76%) EOs, while estragole was the major constituent of A. foeniculum "Aromat de Buzău" (63.27%) and A. mexicana (41.66%) EOs. The investigation of the antiproliferative effect showed that A. rugosa and A. foeniculum "Aromat de Buzău" EOs had significant cytotoxic activity on MDA-MB-231 and HEPG2 tumour cell lines, with the most promising effect on the MDA-MB-231 breast cancer cell line for A. foeniculum "Aromat de Buzău" EO (IC50 = 203.70 ± 0.24 μg/mL). Regarding the antibacterial activity, A. rugosa EO was most active against E. coli (8.91 ± 3.27 μL/mL) and S. aureus (10.80 ± 0.00 μL/mL). To the best of our knowledge, this is the first report on the cytotoxic effect of Agastache sp. EOs on MDA-MB-231, HCT116 and HEPG2 tumour cell lines. The results of our study provide new and promising information for the subsequent in vivo study of the pharmacological properties of Agastache sp. essential oils.

MbEOMT1 regulates methyleugenol biosynthesis in Melaleuca bracteata F. Muell

Methyleugenol, a bioactive compound in the phenylpropene family, undergoes its final and crucial biosynthetic transformation when eugenol O-methyltransferase (EOMT) converts eugenol into methyleugenol. While Melaleuca bracteata F. Muell essential oil is particularly rich in methyleugenol, it contains only trace amounts of its precursor, eugenol. This suggests that the EOMT enzyme in M. bracteata is highly efficient, although it has not yet been characterized. In this study, we isolated and identified an EOMT gene from M. bracteata, termed MbEOMT1, which is primarily expressed in the flowers and leaves and is inducible by methyl jasmonate (MeJA). Subcellular localization of MbEOMT1 in the cytoplasm was detected. Through transient overexpression experiments, we found that MbEOMT1 significantly elevates the concentration of methyleugenol in M. bracteata leaves. Conversely, silencing of MbEOMT1 via virus-induced gene silencing led to a marked reduction in methyleugenol levels. Our in vitro enzymatic assays further confirmed that MbEOMT1 specifically catalyzes the methylation of eugenol. Collectively, these findings establish that the MbEOMT1 gene is critical for methyleugenol biosynthesis in M. bracteata. This study enriches the understanding of phenylpropene biosynthesis and suggests that MbEOMT1 could serve as a valuable catalyst for generating bioactive compounds in the future.

Agastache Species: A Comprehensive Review on Phytochemical Composition and Therapeutic Properties

The Agastache genus is part of the Lamiaceae family and is native to North America, while one species, Agastache rugosa (A. rugosa), is native to East Asia. A review on the phytochemistry and bioactivity of Agastache genus was last performed in 2014. Since then, a lot of progress has been made on the characterization of the phytochemical and pharmacological profiles of Agastache species. Thus, the purpose of this paper is to present a summary of the findings on the phytochemistry and biological effects of several Agastache species, including both extracts and essential oil characterization. We performed a comprehensive search using PubMed and Scopus databases, following PRISMA criteria regarding the study selection process. The available data is focused mainly on the description of the chemical composition and bioactivity of A. rugosa, with fewer reports referring to Agastache mexicana (A. mexicana) and Agastache foeniculum (A. foeniculum). Agastache species are characterized by the dominance of flavonoids and phenolic acids, as well as volatile compounds, particularly phenylpropanoids and monoterpenes. Moreover, a series of pharmacological effects, including antioxidant, cytotoxic, antimicrobial, anti-atherosclerotic, and cardioprotective properties, have been reported for species from the Agastache genus.

AGEs Blocker™ (Goji Berry, Fig, and Korean Mint Mixed Extract) Inhibits Skin Aging Caused by Streptozotocin-Induced Glycation in Hairless Mice

Glycation is a cause of skin aging. This study investigated in a glycation-induced skin aging mouse model the effects on skin and mechanism of action of AGEs Blocker™ (AB), which contains goji berry, fig, and Korean mint mixed extract. This study sought to demonstrate the antiglycation effect of streptozotocin, thereby improving skin aging, by measuring advanced glycation end products (AGEs) and various skin parameters, including collagen; matrix metalloproteinases (MMPs); inflammatory cytokines; activities of oxidative enzymes; and skin wrinkles, elasticity, and hydration. This study found that skin wrinkles, elasticity, and hydration improved with AB. Particularly, the oral administration of AB suppressed AGEs, receptors of AGEs, and carboxymethyl lysine in blood and skin tissue. In addition, AB increased the activities of antioxidative enzymes, reduced inflammatory cytokines, suppressed MMP-9 expression, and increased the contents of collagen and hyaluronic acid, ultimately suppressing skin wrinkles and increasing skin elasticity and hydration. Therefore, AB can inhibit skin aging through its antiglycation effect and is thus considered a good ingredient for skin care products.

Essential Oils as Nematicides in Plant Protection-A Review

By 2030, the European Commission intends to halve chemical pesticide use and its consequent risks. Among pesticides, nematicides are chemical agents used to control parasitic roundworms in agriculture. In recent decades, researchers have been looking for more sustainable alternatives with the same effectiveness but a limited impact on the environment and ecosystems. Essential oils (EOs) are similar bioactive compounds and potential substitutes. Different studies on the use of EOs as nematicides are available in the Scopus database in the scientific literature. These works show a wider exploration of EO effects in vitro than in vivo on different nematode populations. Nevertheless, a review of which EOs have been used on different target nematodes, and how, is still not available. The aim of this paper is to explore the extent of EO testing on nematodes and which of them have nematicidal effects (e.g., mortality, effects on motility, inhibition of egg production). Particularly, the review aims to identify which EOs have been used the most, on which nematodes, and which formulations have been applied. This study provides an overview of the available reports and data to date, downloaded from Scopus, through (a) network maps created by VOSviewer software (version 1.6.8, Nees Jan van Eck and Ludo Waltman, Leiden, The Netherlands) and (b) a systematic analysis of all scientific papers. VOSviewer created maps with keywords derived from co-occurrence analysis to understand the main keywords used and the countries and journals which have published most on the topic, while the systematic analysis investigated all the documents downloaded. The main goal is to offer a comprehensive understanding of the potential use of EOs in agriculture as well as which directions future research should move toward.

Effects of Carbohydrates on Rosmarinic Acid Production and In Vitro Antimicrobial Activities in Hairy Root Cultures of Agastache rugosa

Agastache rugosa (popularly known as Korean mint) belongs to the Lamiaceae family and comprises 22 species of perennial aromatic medicinal species native to East Asian countries, such as Korea, Taiwan, Japan, and China. A. rugosa contains many phenolic compounds that exhibit pharmacological and physiological activities, including antioxidant, anticancer, antiviral, antifungal, and antibacterial activities. The highest concentrations of rosmarinic acid and its isomers have been reported in the roots of A. rugosa. In this in vitro study, hairy roots of A. rugosa were obtained and the carbohydrates (sorbitol, mannitol, glucose, maltose, galactose, mannose, and sucrose) were evaluated to determine those that were optimal for rosmarinic acid production and hairy root growth. Antioxidant and antibacterial activities of extracts of A. rugosa were also assessed. The best carbon source for A. rugosa hairy root cultures was sucrose, considering biomass productivity (0.460 ± 0.034 mg/30 mL), rosmarinic acid production (7.656 ± 0.407 mg/g dry weight), and total phenolic content (12.714 ± 0.202 mg/g gallic acid equivalent). Antioxidant and antimicrobial activities were displayed by A. rugosa hairy roots cultured in liquid medium supplemented with 100 mM sucrose. Twenty-five bacterial strains, including multidrug-resistant bacteria and one pathogenic yeast strain, were used for antimicrobial screening of A. rugosa hairy roots. The hairy root extracts displayed antibacterial activity against Micrococcus luteus (KCTC 3063) and Bacillus cereus (KCTC 3624). The inhibition of these bacteria was greater using A. rugosa hairy roots with the highest levels of phenolic compounds cultured in the presence of sucrose, compared to hairy roots with the lowest levels of phenolic compounds cultured in the presence of fructose. Considering hairy root biomass, phenolic compound production, and antibacterial activity, sucrose is the best carbon source for A. rugosa hairy root cultures.

Establishing DNA markers to differentiate Agastache rugosa and Pogostemon cablin, which are confusedly used as medicinal herbs, using real-time PCR

Agastache rugosa and Pogostemon cablin are used as medicinal herbs and aromatic plants and belong to the family Lamiaceae. Despite differences in composition and physicochemical properties, both plants are frequently sold as the medical substance "Kwakhyang" in some Asian countries. Molecular markers were established to distinguish between the two plants using quantitative real-time PCR. Species-specific primers were designed in the nuclear internal transcribed spacer region of ribosomal DNA and in the chloroplast genes matK, rbcL, and rpoB. Six primer sets were tested, the correlation coefficient was higher than 0.99, and the slope was approximately - 3.36 to - 3.58. Efficiency ranged from 90.13 to 98.52%. The developed real-time PCR assay was validated with 14 off-target species, and its reliability was verified through blind testing of 14 commercial products. The assay developed here may help protect consumer rights, and the designed primers can be used to distinguish between the target species.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10068-022-01176-y.

Bridging the Chemical Profile and Biological Activities of a New Variety of Agastache foeniculum (Pursh) Kuntze Extracts and Essential Oil

This study investigated the phytochemical content of alcoholic extracts and essential oil of a new variety of medicinal plants, Agastache foeniculum (Pursh), which Kuntze adapted for cultivation in Romania, namely “Aromat de Buzău”. The essential oil was investigated by GC-MS, while the identification and quantification of various compounds from alcoholic extracts were performed by HPLC-DAD. The total phenol and flavonoid contents of the extracts were evaluated by using standard phytochemical methods. The antioxidant activities of ethanol, methanol extracts, and essential oil of the plant were also assessed against 2,2′-diphenyl-1-picrylhydrazyl (DPPH•), 2,2′-azino-bis-(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS•+), and by ferric reducing power (FRAP) using spectroscopic methods. Cyclic voltammetry was used to evaluate the antioxidant capacity of the essential oil. The concentrations of phenolic compounds were higher in methanolic extract compared to ethanolic extract. A significant correlation was found between total phenol and total flavonoid contents (r = 0.9087). Significant high correlations were also found between the total phenolic compounds and the antioxidant activities of the extracts (r ≥ 0.8600, p < 0.05). In addition, the extracts and essential oil showed good antioxidant and xanthine oxidase inhibitory activities. Estragole was detected as the major constituent of the essential oil (94.89%). The cytotoxic activity of the essential oil was evaluated by the MTT assay. At lower concentrations (1 µg/mL) high cytotoxicity against MCF-7 breast cancer cells was observed but not on the non-tumoral dermal fibroblasts (HDF) which indicated selectivity for cancer cells and suggests the presence of biologically active components that contribute to the observed high cytotoxic effect. Findings from the present study offer new perspectives on the use of A. foeniculum as a potential source of bioactive compounds and a good candidate for pharmaceutical plant-based products.

Chemical Diversity of Essential Oils from Korean Native Populations of Agastache rugosa (Korean Mint)

Agastache rugosa (baechohyang) is one of the most important aromatic plants native to the Republic of Korea. A. rugosa fragrance has been used to prepare incense since the Goryeo Dynasty in Korea. The present study aimed to explore the variation in the composition of essential oils from A. rugosa among native populations in Korea. The seeds of A. rugosa were collected from 90 different sites in Korea and seedlings were raised in the nursery. Essential oils were extracted from these populations by the steam distillation extraction method and their chemical compositions were analyzed by GC-MS. The yield of essential oils of A. rugosa ranged between 0.11% and 0.86%. A total of 204 components were identified from 90 populations of A. rugosa. Out of 204 components, 32 components were common in more than 40 individuals of A. rugosa and these 32 components were selected for principal component analysis (PCA). On the basis of the essential oil compositions, six chemotypes—estragole, pulegone, methyl eugenol, menthone, isopulegone, and nepetalactone—were distinguished according to their major components. As a result of the cluster analysis, 90 individuals of A. rugosa could be classified into three groups: estragole, methyl eugenol, and pulegone. A. rugosa exhibited significant chemical diversity among the individuals. The distribution of chemotypes is associated with the collection of seeds, suggesting that genetic diversity may influence the variations in the chemical compositions and concentrations within the species. This chemical diversity serves as the background to select cultivars for the cultivation and industrial applications of A. rugosa cultivars with high essential oil yield and concentration of its chemical components.

Antifungal, repellency, and insecticidal activities of Cymbopogon distans and Ruta graveolens essential oils and their main chemical constituents

Essential oils produced by Cymbopogon distans and Ruta graveolens with a similar Chinese name could be explained as book fragrance in the Chinese idiom, "shu xiang men di", namely, a wealthy intellectual family according to ancient Chinese. Therefore , volatile oils from these two plants and their main compounds were tested to explore their antifungal, repellent and insecticide actions. In this study, essential olis (EOs) of C. distans exhibited significant antifungal activity against Rhizopus stolonifera ( 97%), Mucor racemosus (97%), and Trichoderma viride (84%); its main compounds display interesting activity, such as methyleugenol (87%) and elemicine (85%) against T. viride , and butyl hydroxytoluene against M. racemosus (90%) and R. stolonifera (95%). EOs of R. graveolens and other major chemical constituents showed weak inhibitory effects against other fungi ( Aspergillus flavus and Fusarium oxysporum ). Then, EOs ( C. distans and R. graveolens ) and its main compounds exhibited obvious repellent activity (more than 85%) at the concentration of 16 nL/cm², which was consistent with the repellency of the positive control (DEET). In terms of insecticidal activity, the mortality of C. distans volatile oil against R. padi (56.4%) was lower than that of R. graveolens volatile oil (92.4%), and all compounds showed strong lethal effects. These results provide a natural substance for controlling fungi and insects when storing books, and which can be used as a biological pesticide for industrial production. Through our study, the book fragrance in the Chinese idiom "shu xiang men di" was speculated to be the EO odor of C. distans.

Changes in Human Electroencephalographic Activity in Response to Agastache rugosa Essential Oil Exposure

Agastache rugosa (Korean mint) is an important medicinal and aromatic plant and its aerial parts have a pleasant fragrance. A. rugosa leaves are used as an ingredient in salads and soups for enhancing the aroma and taste of foods in Korea. However, there is no report on the influence of the aroma of A. rugosa on human psychophysiological activity. Therefore, the present study aimed to investigate the effect of exposure to the essential oil of Korean A. rugosa on human electroencephalographic (EEG) activity. The essential oil of A. rugosa was isolated using steam distillation extraction and its composition was determined by gas chromatography and mass spectrometry (GC–MS) analysis. In the EEG study, 38 healthy volunteers (19 men and 19 women) participated. The EEG readings were analyzed for 25 EEG indices from 29 electrodes placed on the scalp according to the international 10–20 system. The major component in the essential oil of A. rugosa was estragole (89.49%) followed by D-limonene (3.40%), menthone (1.80%), and pulegone (1.86%). In the EEG study, significant decreases in absolute theta (AT) and relative theta (RT) power spectra were observed during the exposure to A. rugosa essential oil when compared to that of no odor exposure. Whereas relative alpha (RA), relative slow alpha (RSA), spectral edge frequency 50% (SEF50), and spectral edge frequency 50% of alpha (ASEF) power spectra values significantly increased. These results reveal that the EEG power spectra changes incurred during the exposure to the essential oil of A. rugosa may be associated with the enhancement of freshness and concentration states of the human brain.

Nematicidal Effects of Volatile Organic Compounds from Microorganisms and Plants on Plant-Parasitic Nematodes

Plant-parasitic nematodes (PPNs) are one of the most destructive plant pathogens worldwide, and controlling them is extremely challenging. Volatile organic compounds (VOCs), which naturally exist in plants and microorganisms, play an important role in the biological control of PPNs and are considered potential substances for the development of commercial nematicides. This paper summarizes the VOCs produced by microorganisms and plants as well as their toxic effects on PPNs. VOCs from 26 microbial strains and 51 plants that are active against nematodes from over the last decade were reviewed. Furthermore, the mechanisms of toxicity of some VOCs against PPNs are also illustrated.

Pesticidal Activity and Mode of Action of Monoterpenes

Synthetic pesticides are often associated with issues such as pest resistance, persistent residue, nontarget toxicity, and environmental issues. Therefore, the research and development of novel, safe, and effective pesticides has become a focus in pesticide discovery. Monoterpenes are secondary plant metabolites that commonly have multiple action targets and have been used in aromatherapy, alternative medicine, and food industries. Some are highly potent and stereoselective. They can potentially be botanical pesticides and serve as lead candidates for the design and synthesis of new monoterpenoid pesticides for agricultural applications. This article reviews publications and patents found in SciFinder Scholar between 2000 and May 2021 on monoterpenes and mainly focuses on pesticidal activities of frequently studied monoterpenes and their modes of action. The presented information and our views are hopefully useful for the development of monoterpenes as biopesticides and monoterpenoid pesticides.

A Review of the Potency of Plant Extracts and Compounds from Key Families as an Alternative to Synthetic Nematicides: History, Efficacy, and Current Developments

The global nematicides market is expected to continue growing. With an increasing demand for synthetic chemical-free organic foods, botanical nematicides are taking the lead as replacements. Consequently, in the recent years, there have been vigorous efforts towards identification of the active secondary metabolites from various plants. These include mostly glucosinolates and their hydrolysis products such as isothiocyanates; flavonoids, alkaloids, limonoids, quassinoids, saponins, and the more recently probed essential oils, among others. And despite their overwhelming potential, variabilities in quality, efficacy, potency and composition continue to persist, and commercialization of new botanical nematicides is still lagging. Herein, we have reviewed the history of botanical nematicides and regional progresses, the potency of the identified phytochemicals from the key important plant families, and deciphered some of the impediments involved in standardization of the active compounds in addition to the concerns over the safety of the purified compounds to non-target microbial communities.

Chemical composition and biological activities of essential oils from six lamiaceae folk medicinal plants

Essential oils have attracted wide attention in recent years due to their extensive applications in natural functional ingredients, pharmaceutical preparations, biomedical products, and the cosmetics industry. In this study, the chemical compositions and biological activities of essential oils extracted from six Lamiaceae herbs, including Pogostemon cablin (Blanco) Benth. (PCEO), Perilla frutescens (L.) Britton (PFEO), Salvia japonica Thunb. (SJEO), Rosmarinus officinalis L. (ROEO), Lavandula angustifolia Mill. (LAEO), and Agastache rugosa (Fisch. & C. A. Mey.) Kuntze (AREO), were determined and analyzed. A total of 167 components were identified from the six essential oils by GC-MS analysis, with 35, 24, 47, 46, 54, and 37 components in PCEO, PFEO, SJEO, ROEO, LAEO, and AREO, respectively. Hierarchical cluster analysis of chemical compositions showed that the composition of the six essential oils was significantly different in content, and they were clearly divided into six classes. However, all of these six essential oils exhibited promising anti-inflammatory activity by inhibiting the expression of interleukin-1, interleukin-6, tumor necrosis factor-α, and cyclooxygenase-2 in rats with adjuvant arthritis, among which PFEO had the best performance. In addition, the six essential oils displayed significant cytotoxicity on B16 (IC₅₀ = 86.91-228.91 μg/mL) and LNCaP cell lines (IC₅₀ = 116.4-189.63 μg/mL). Meanwhile, all of them presented satisfactory antioxidant activity (IC₅₀ = 4.88-13.89 μg/mL) compared with Trolox C (IC₅₀ = 13.83 μg/mL), and SJEO (IC₅₀ = 7.93 μg/mL) served as an optimal candidate natural antioxidant by DPPH assay. Taken together, these results indicate that the six Lamiaceae essential oils manifest excellent and diverse biological activities, enabling them to be used as perfect natural functional ingredients in antioxidant, antitumor, or anti-arthritic drugs. This study provides more references for pharmaphylogeny research and drug discovery from folk medicinal plants.

Comparison of Pulegone and Estragole Chemotypes Provides New Insight Into Volatile Oil Biosynthesis of Agastache rugosa

The aerial parts of Agastache rugosa are rich in essential oils containing monoterpenoids, phenylpropanoids, and aromatic compounds. These are used as herbs, perfume plants, and ornamental plants. Based on the difference in the constituents of the essential oil, A. rugosa is divided into pulegone and estragole chemotypes, but the mechanism of key metabolite biosynthesis in these two A. rugosa chemotypes remains unclear. In this study, we compared the morphological differences, metabolite constituents, and transcriptomic data between the two chemotypes of A. rugosa. Monoterpenoid was the main compound in the pulegone chemotype, and phenylpropanoid was the main compound in the estragole chemotype; however, limonene was detected in both chemotypes. Furthermore, 46 genes related to pulegone and estragole biosynthesis were identified. Limonene synthase, limonene-3-hydroxylase, and isopiperitenol dehydrogenase were upregulated in the pulegone chemotype, while phenylalanine ammonia-lyase, 4-coumarate: CoA ligase, CYP73A, coumaroyl-aldehyde dehydrogenase, and eugenol synthase were downregulated in the pulegone chemotype. We identified chavicol methyl transferase and limonene-3-hydroxylase in A. rugosa. This work not only provides the difference in morphology and metabolites in pulegone and estragole chemotypes, but also offers a molecular mechanism of volatile oil biosynthesis, which could be a basis for specialized metabolites in specialized chemotypes.

Network Pharmacology-Based Analysis of Pogostemon cablin (Blanco) Benth Beneficial Effects to Alleviate Nonalcoholic Fatty Liver Disease in Mice

Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease and is associated with high morbidity and mortality. Pogostemon cablin (Blanco) Benth/Huo Xiang (HX) is a perennial herb with unique anti-oxidant and anti-inflammatory properties, and thus, can positively affect liver function. In this study, we used network pharmacology to predict the potential mechanism of HX on NAFLD. Pharmacological experiments were used to verify the effect of HX on the functions of NAFLD. Network pharmacology identified nine components that interacted with 82 NAFLD-related targets, revealing four target genes: TNF, IL6, TP53, and AKT1. HX prevents the development and progression of NAFLD through different pathways and targets with quercetin-regulated lipid metabolism, anti-inflammatory, and anti-oxidant pathways playing an essential role in the treatment of NAFLD. Compared with feeding HFD, HX significantly attenuated lipid accumulation in vivo with mice and also in vitro with mouse liver cells. A high dose of HX decreased hepatocyte lipid accumulation and the abundance of SREBF1 and FASN. Validation experiments revealed that HX inhibited the activation of NF-κB/IκB signaling and decreased the release and levels of pro-inflammatory factors (TNF-α and IL-6). These data suggest that HX can attenuate abnormal lipid metabolic responses and enhance antioxidant mechanisms. Thus, the pharmacological effects from plants used in traditional Chinese medicine are achievde through a multi-level response.

Molecular cloning and pharmacology of Min-UNC-49B, a GABA receptor from the southern root-knot nematode Meloidogyne incognita

BACKGROUND

Root-knot nematodes are plant-parasitic nematodes that cause immense damage to a broad range of cultivated crops by forming root galls, resulting in yield losses in crops. To facilitate the development of faster-acting selective nematicides, we cloned three cDNAs encoding UNC-49B proteins from the southern root-knot nematode Meloidogyne incognita and examined their functional and pharmacological properties by two-electrode voltage clamp electrophysiology using a Xenopus oocyte expression system.

RESULTS

The three cloned cDNAs encoded Min-UNC-49B, Min-UNC-49B-L and Min-UNC-49B-XL; the last two proteins have longer N-terminal regions than the first protein. When expressed in Xenopus oocytes, these proteins responded to γ-aminobutyric acid (GABA) to activate currents with high-micromolar or low-millimolar half-maximal effective concentration (EC₅₀ ) values, indicating the formation of functional homo-pentameric GABA receptors. Fipronil and picrotoxinin inhibited GABA-induced currents with high-nanomolar and low-micromolar half-maximal inhibitory concentration (IC₅₀ ) values, respectively, in oocytes expressing Min-UNC-49B. The G2'A and T6'M mutations in the second transmembrane domain of Min-UNC-49B enhanced and reduced the sensitivity of Min-UNC-49B to these two antagonists, respectively. Samaderine B and SF-14 inhibited GABA responses in oocytes expressing Min-UNC-49B with low-micromolar and high-nanomolar IC₅₀ values, respectively. Ivermectin, α-terpineol, thymol and methyl eugenol exerted dual effects on Min-UNC-49B by potentiating currents induced by low concentrations of GABA and inhibiting currents induced by high concentrations of GABA.

CONCLUSION

We have shown that structurally diverse compounds act at Min-UNC-49B GABA receptors. Our results may serve as a starting point to decipher the molecular function of native GABA receptors of plant-parasitic nematodes, which could aid in the structure-based design of novel nematicides. © 2020 Society of Chemical Industry.

The Advantage of Automatic Peer-Reviewing of 13C-NMR Reference Data Using the CSEARCH-Protocol

A systematic investigation of the experimental ¹³C-NMR spectra published in Molecules during the period of 1996 to 2015 with respect to their quality using CSEARCH-technology is described. It is shown that the systematic application of the CSEARCH-Robot-Referee during the peer-reviewing process prohibits at least the most trivial assignment errors and wrong structure proposals. In many cases, the correction of the assignments/chemical shift values is possible by manual inspection of the published tables; in certain cases, reprocessing of the original experimental data might help to clarify the situation, showing the urgent need for a public domain repository. A comparison of the significant key numbers derived for Molecules against those of other important journals in the field of natural product chemistry shows a quite similar level of quality for all publishers responsible for the six journals under investigation. From the results of this study, general rules for data handling, data storage, and manuscript preparation can be derived, helping to increase the quality of published NMR-data and making these data available as validated reference material.

A Systematic Review of Antiaging Effects of 23 Traditional Chinese Medicines

BACKGROUND

Aging is an inevitable stage of body development. At the same time, aging is a major cause of cancer, cardiovascular disease, and neurodegenerative diseases. Chinese herbal medicine is a natural substance that can effectively delay aging and is expected to be developed as antiaging drugs in the future. Aim of the review. This paper reviews the antiaging effects of 23 traditional Chinese herbal medicines or their active components. Materials and methods. We reviewed the literature published in the last five years on Chinese herbal medicines or their active ingredients and their antiaging role obtained through the following databases: PubMed, EMBASE, Scopus, and Web of Science.

RESULTS

A total of 2485 papers were found, and 212 papers were screened after removing the duplicates and reading the titles. Twenty-three studies met the requirements of this review and were included. Among these studies, 13 articles used Caenorhabditis elegans as the animal model, and 10 articles used other animal models or cell lines.

CONCLUSION

Chinese herbal medicines or their active components play an antiaging role by regulating genes related to aging through a variety of signaling pathways. Chinese herbal medicines are expected to be developed as antiaging drugs or used in the medical cosmetology industry.

Tilianin attenuates HDM-induced allergic asthma by suppressing Th2-immune responses via downregulation of IRF4 in dendritic cells

BACKGROUND

Acacetin 7-O-β-D-glucoside (tilianin) is a major constituent of Agastache rugosa, a traditional medicine that has long been used for the treatment of gastrointestinal disorders. Tilianin has a wide variety of pharmacological properties such as cardioprotective, neuroprotective, and anti-atherogenic activities. We recently discovered that tilianin has the ability to suppress MUC5AC expression in vitro. In addition, we have established an in vivo model of allergic asthma using house dust mite (HDM) that can be applied to tilianin.

PURPOSE

We investigated the effects of tilianin on airway inflammation in a HDM-induced asthma mouse model and associated mechanisms.

METHODS

Tilianin was treated in splenocytes cultured in Th0 condition and HDM-stimulated bone marrow-derived dendritic cells (BMDCs), and their mRNA expression and cytokines production were determined by quantitative real-time PCR and ELISA. To evaluate the effects of tilianin in an allergic asthma model, mice were sensitized and challenged with HDM. Tilianin was administered prior to challenge by oral gavage and airway hyper-reactivity (AHR) to methacholine, inflammatory cell infiltration, cytokine levels, and airway remodeling were assessed.

RESULTS

Tilianin inhibited the production of Th2-related cytokines in splenocytes, which play pivotal roles in allergic airway inflammation. When treated in HDM-stimulated BMDCs, tilianin decreased Th2-skewing cytokine IL-33 and transcription factor IRF4. On the contrary, tilianin increased Th1-skewing regulators, IL-12 and IRF1. In an HDM-induced asthmatic mouse model, tilianin attenuated AHR and airway inflammation. Tilianin suppressed the expression of Th2-related cytokines, IL-13 and IL-33 in lung tissues. As seen in HDM-stimulated BMDCs, tilianin also downregulated the expression of the transcription factor IRF4 but not IRF1.

CONCLUSION

Taken together, these results suggest that tilianin attenuates HDM-induced allergic airway inflammation by inhibiting Th2-mediated inflammation through the selective inhibition of the IRF4-IL-33 axis in dendritic cells.

Essential Oils of Lamiaceae Family Plants as Antifungals

The incidence of fungal infections has been steadily increasing in recent years. Systemic mycoses are characterized by the highest mortality. At the same time, the frequency of infections caused by drug-resistant strains and new pathogens e.g., Candida auris increases. An alternative to medicines may be essential oils, which can have a broad antimicrobial spectrum. Rich in the essential oils are plants from the Lamiaceae family. In this review are presented antifungal activities of essential oils from 72 Lamiaceae plants. More than half of these have good activity (minimum inhibitory concentrations (MICs) < 1000 µg/mL) against fungi. The best activity (MICs < 100) have essential oils from some species of the genera Clinopodium, Lavandula, Mentha, Thymbra, and Thymus. In some cases were observed significant discrepancies between different studies. In the review are also shown the most important compounds of described essential oils. To the chemical components most commonly found as the main ingredients include β-caryophyllene (41 plants), linalool (27 plants), limonene (26), β-pinene (25), 1,8-cineole (22), carvacrol (21), α-pinene (21), p-cymene (20), γ-terpinene (20), and thymol (20).

Chemical Constituents from the Aerial Parts of Agastache rugosa and Their Inhibitory Activities on Prostaglandin E2 Production in Lipopolysaccharide-Treated RAW 264.7 Macrophages

A new flavone glucoside, acacetin-7-O-(3″-O-acetyl-6″-O-malonyl)-β-d-glucopyranoside (1), two new phenolic glucosides, (3R,7R)-tuberonic acid-12-O-[6'-O-(E)-feruloyl]-β-d-glucopyranoside (14) and salicylic acid-2-O-[6'-O-(E)-feruloyl]-β-d-glucopyranoside (15), and two new phenylpropanoid glucosides, chavicol-1-O-(6'-O-methylmalonyl)-β-d-glucopyranoside (17) and chavicol-1-O-(6'-O-acetyl)-β-d-glucopyranoside(18), as well as 26 known compounds, 2-13, 16, and 19-31, were isolated from the aerial parts of Agastache rugose. The structures of the new compounds were established by spectroscopic/spectrometric methods such as HRESIMS, NMR, and ECD. The anti-inflammatory effect of the isolated compounds was evaluated by measuring their inhibitory activities on prostaglandin E₂ (PGE₂) in lipopolysaccharide (LPS)-treated RAW 264.7 macrophages. New compounds 1, 15, 17, and 18 inhibited LPS-induced PGE₂ production with IC₅₀ values of 16.8 ± 0.8, 33.9 ± 4.8, 14.3 ± 2.1, and 48.8 ± 4.4 μM, respectively. Compounds 5, 7, 9-11, 13, 19, 20, 22, and 27-30 showed potent inhibitory activities with IC₅₀ values of 1.7-8.4 μM.

Biocatalytic Synthesis of Non-Natural Monoterpene O-Glycosides Exhibiting Superior Antibacterial and Antinematodal Properties

A promiscuous Bacillus glycosyltransferase (YjiC) was explored for the enzymatic synthesis of monoterpene O-glycosides in vitro and in vivo. YjiC converted seven monoterpenes into 41 different sugar-conjugated novel glycoside derivatives. The whole-cell biotransformation of the same set of monoterpenes exhibited robust enzyme activity to synthesize O-glucosyl derivatives from Escherichia coli. These newly synthesized selected monoterpene-O-glucosyl derivatives exhibited enhanced antibacterial activities against human pathogenic bacteria and antinematodal activities against pine wood nematode Bursaphelenchus xylophilus.

In Vitro Antioxidant and Antimicrobial Properties of Flower, Leaf, and Stem Extracts of Korean Mint

Traditionally, Agastache rugosa (Korean mint) has been widely used to treat various infectious diseases. The aims of this study were to: (i) determine the phenylpropanoid content of the plant using high-performance liquid chromatography; (ii) undertake total anthocyanin, flavonoid, and phenolic assays; (iii) and evaluate the antioxidant and antibacterial properties of the methanol extracts from the stem, leaves, and flowers of Korean mint. The total anthocyanin, flavonoid, and phenolic content assays showed that the flowers had higher phenolic levels than the stem and leaves. The reducing power, the 2,2-diphenyl-1-picrylhydrazyl superoxide radical scavenging abilities, and the hydrogen peroxide radical scavenging activities were also evaluated so that the antioxidant activities of the extracts from the different plant parts could be evaluated. The flower extracts revealed higher antioxidant properties than the other parts. The antibacterial properties of the methanol extracts from A. rugosa were analyzed by the disc diffusion method, and the flower extracts had higher antibacterial activities against the six bacterial strains used in the study than the other parts. This study provides information on the synergistic antioxidant and antibacterial properties of phenolics derived from the different parts of Korean mint.

Probiotic fermentation augments the skin anti-photoaging properties of Agastache rugosa through up-regulating antioxidant components in UV-B-irradiated HaCaT keratinocytes

Background

Agastache rugosa (Fisch. & C.A.Mey.) Kuntze (Korean mint) is used to treat diverse types of human disorders in traditional medicine. In recent years, its non-fermented leaf extract (ARE) has been shown to possess protective properties against ultraviolet-B (UV-B) radiation-induced photooxidative stress. The present work aimed to examine whether probiotic bacterial fermentation would potentiate the skin anti-photoaging activity of ARE or not, by comparing the protective properties of ARE and corresponding fermented extract (ARE-F) against UV-B radiation-induced photooxidative stress in HaCaT keratinocytes.

Methods

ARE-F was produced from ARE by the fermentation with Lactobacillus rhamnosus HK-9, a type of Gram-positive probiotic bacterial strain. Anti-photoaging activities were evaluated by analyzing reactive oxygen species (ROS), promatrix metalloproteinases (proMMPs), total glutathione (GSH) and total superoxide dismutase (SOD) in UV-B-irradiated HaCaT keratinocytes. Antiradical activity was determined using 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging assay.

Results

ARE-F contained higher attenuating activity on the UV-B-induced ROS generation than ARE. Similarly, ARE-F was able to diminish the UV-B-induced proMMP-9 and -2 more effectively than ARE. ARE-F displayed higher tendencies to augment the UV-B-reduced total GSH content and SOD activity than ARE. However, there were no significant difference between ARE and ARE-F in ABTS radical scavenging activities.

Conclusions

The findings suggest that the UV-B radiation-protective activity of ARE is enhanced by probiotic bacterial fermentation, which might improve the therapeutic and cosmetic values of A. rugosa leaves.

Chemical composition, immunostimulatory, cytotoxic and antiparasitic activities of the essential oil from Brazilian red propolis

Most studies of Brazilian red propolis have explored the composition and biological properties of its ethanolic extracts. In this work, we chemically extracted and characterized the essential oil of Brazilian red propolis (EOP) and assessed its adjuvant, antiparasitic and cytotoxic activities. The chemical composition of EOP was analyzed using gas chromatography with mass spectrometry (GC-MS). EOP was tested for in vitro activity against Trichomonas vaginalis (ATCC 30236 isolate); trophozoites were treated with different concentrations of EOP (ranging from 25 to 500 μg/mL) in order to establish the MIC and IC₅₀ values. A cytotoxicity assay was performed in CHO-K1 cells submitted to different EOP concentrations. BALB/c mice were used to test the adjuvant effect of EOP. The animals were divided in 3 groups and inoculated as follows: 0.4 ng/kg BW EOP (G1); 50 μg of rCP40 protein (G2); or a combination of 0.4 ng/kg BW EOP and 50 μg of rCP40 (G3). Total IgG, IgG1 and IgG2a levels were assessed by ELISA. The major constituent compounds of EOP were methyl eugenol (13.1%), (E)-β-farnesene (2.50%), and δ-amorphene (2.3%). Exposure to EOP inhibited the growth of T. vaginalis, with an IC₅₀ value of 100 μg/mL of EOP. An EOP concentration of 500 μg/mL was able to kill 100% of the T. vaginalis trophozoites. The EOP kinetic growth curve showed a 36% decrease in trophozoite growth after a 12 h exposure to 500 μg/mL of EOP, while complete parasite death was induced at 24 h. With regard to CHO-K1 cells, the CC₅₀ was 266 μg/mL, and 92% cytotoxicity was observed after exposure to 500 μg/mL of EOP. Otherwise, a concentration of 200 μg/mL of EOP was able to reduce parasite proliferation by 70% and was not cytotoxic to CHO-K1 cells. As an adjuvant, a synergistic effect was observed when EOP was combined with the rCP40 protein (G3) in comparison to the administration of each component alone (G1 and G2), resulting in higher concentrations of IgG, IgG1 and IgG2a. EOP is constituted by biologically active components with promising antiparasitic and immunostimulatory activities and can be investigated for the formulation of new vaccines or trichomonacidal drugs.

Antioxidant Activity of the Essential Oil and its Major Terpenes of Satureja macrostema (Moc. and Sessé ex Benth.) Briq

BACKGROUND

The aim of this study was to investigate the in vitro antioxidant activity of Satureja macrostema (Moc. and Sessé ex Benth.) Briq. (Lamiaceae) essential oil, a Mexican medicinal plant known as nurite.

MATERIALS AND METHODS

Fresh aerial parts of S. macrostema plants cultivated in greenhouse for 3 months were subjected to hydrodistillation in a Clevenger apparatus to obtain essential oil. Volatile compounds were identified by gas chromatography (GC) and GC/mass spectrometry. Antioxidant effectiveness of essential oil and its major terpenes of S. macrostema was examined by three different radical scavenging methods: 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azinobis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS), and total antioxidant capacity (TAC). The concentrations tested were 0.001, 0.01, 0.1, and 1 mg/mL.

RESULTS

The major volatile compounds were caryophyllene, limonene, linalool, pulegone, menthone, and thymol. S. macrostema essential oil showed the highest free radical scavenging activity with DPPH and ABTS methods (53.10% and 92.12%, respectively) at 1 mg/mL and 98% with TAC method at 0.1 mg/mL. Thymol exerted the highest antioxidant capacity with 0.1 mg/mL, reaching 83.38%, 96.96%, and 98.57% by DPPH, ABTS, and TAC methods. Caryophyllene, limonene, linalool, pulegone, and menthone exhibited an antioxidant capacity <25% with the DPPH and ABTS methods; however, limonene showed a TAC of 85.41% with 0.01 mg/mL.

CONCLUSION

The essential oil of S. macrostema and thymol showed a free radical scavenging activity close to that of the synthetic butylated hydroxytoluene.

SUMMARY

The major volatile compounds of essential oil of Satureja macrostema were caryophyllene, limonene, linalool, pulegone, menthone and thymolThe essential oil of S. macrostema showed a high free radical scavengingThymol exerted the highest antioxidant capacity by DPPH, ABTS and TAC methods. Abbreviations used: GC: Gas Chromatography; DPPH: 2,2-diphenyl-1-picrylhydrazyl; ABTS: 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid; TAC: Total antioxidant capacity.

Chemical constituents and coagulation activity of Agastache rugosa

Background

In the Chinese traditional medicine, plant of Agastache rugosa (Fisch. & C.A. Mey.) Kuntze (A. rugosa) has been used to treat nausea, vomiting and dispel damp. However, currently, few reports about the chemical constituents, especially the non-volatile components of A. rugosa are available.

Methods

Through separation with various column chromatographies to elucidate the chemical constituents of A. rugosa, the biological activities of the major constituents were investigated. The extracts and main constituents of A. rugosa were evaluated for their anticoagulant effects by assaying the activated partial thromboplastin time (APTT), prothrombin time (PT), thrombin time (TT) and fibrinogen (FIB) in vitro.

Results

Seven known compounds (namely compounds 1–7) were isolated from the aerial parts of A. rugosa. They were identified as methyl hexadecanoate (1), β-sitosterol (2), acacetin (3), ursolic acid (4), apigenin (5), protocatechuic acid (6) and tilianin (7), respectively. Compounds 1 and 6 were isolated from the genus Agastache for the first time, and compound 4 was obtained from the plants for the first time. The results showed that the extract of A. rugosa had a significant procoagulant activity by shortening the time of PT (P < 0.001) and increasing FIB content (P < 0.001), as compared with Vitamin K₁. While its major constituents acacetin and tilianin exhibited significant anticoagulant activities by prolonging the times of PT, APTT, TT and reducing FIB content (P < 0.001), as compared with blank control group.

Conclusions

The total extract of A. rugosa possessed significant procoagulant activity, while its main components, acacetin and tilianin possessed significant anticoagulant activities. Further investigation should be pursued to find out the bioactivity components responsible for the procoagulant action of the plant.

Repellent and Anti-quorum Sensing Activity of Six Aromatic Plants Occurring in Colombia

Essential oils (EOs) are widely used as biopesticides and to control bacterial infections. This study describes the ability of six EOs isolated from plants cultivated in Colombia to perform as repellents against Ulomoides dermestoides and as quorum sensing (QS) inhibitors. EOs from Aloysia triphylla, Cymbopogon nardus, Lippia origanoides, Hyptis suaveolens, Swinglea glutinosa ami Eucalyptus globulus were repellents classified as Class IV, IV, IV, III, II, and II, respectively, whereas the commercial repellent IR3535 only reached Class II after 2 h exposure. All EOs presented small, but significant inhibitory properties against the QS system in Escherichia coli (pJBA132) at 25 μg/mL after 4 h exposure. These data suggest evaluated EOs from Colombia are sustainable, promising new sources of natural repellents and could be important as anti-quorum sensing molecules.

Advanced development in phytochemicals analysis of medicine and food dual purposes plants used in China (2011-2014)

In 2011, we wrote a review for summarizing the phytochemical analysis (2006-2010) of medicine and food dual purposes plants used in China (Zhao et al., J. Chromatogr. A 1218 (2011) 7453-7475). Since then, more than 750 articles related to their phytochemical analysis have been published. Therefore, an updated review for the advanced development (2011-2014) in this topic is necessary for well understanding the quality control and health beneficial phytochemicals in these materials, as well as their research trends.

Evaluation of Antidiabetic and Antihyperlipidemic Effects of Hydroalcoholic Extract of Leaves of Ocimum tenuiflorum (Lamiaceae) and Prediction of Biological Activity of its Phytoconstituents

Objective:

The aim was to evaluate the anti-diabetic and anti-hyperlipidemic effects of hydroalcoholic extract of leaves of Ocimum tenuiflorum (Lamiaceae) and prediction of biological activities of its phytoconstituents using in vivo anti-diabetic model and in silico analysis respectively.

Materials and Methods:

The leaves of O. tenuiflorum were extracted with 60% ethanol, and the extract was used for further pharmacological screening. The acute toxicity of the extract was evaluated as per the guidelines set by the Organization for Economic Co-operation and Development, revised draft guidelines 423. The oral anti-diabetic activity of the hydroalcoholic extract of O. tenuiflorum (125, 250 and 500 mg/kg) was studied against streptozotocin (STZ) (50 mg/kg; i.p.) + nicotinamide (120 mg/kg; i.p.) induced diabetes mellitus. The animals were treated with the investigational plant extract and standard drug (glibenclamide) for 21 consecutive days and the effect of hydroalcoholic extract of O. tenuiflorum on blood glucose levels was measured at regular intervals. At the end of the study, blood samples were collected from all the animals for biochemical estimation, then the animals were sacrificed and the liver and kidney were collected for organ weight analysis. Prediction for pharmacological and toxicological properties of phytoconstituents of O. tenuiflorum was carried out using online web tools such as online pass prediction and lazar toxicity prediction.

Results:

The hydroalcoholic extract of O. tenuiflorum showed significant anti-diabetic and anti-hyperlipidemic activity at 250 and 500 mg/kg, and this effect was comparable with that of glibenclamide. Predicted biological activities of phytoconstituents of O. tenuiflorum showed presence of various pharmacological actions, which includes anti-diabetic and anti-hyperlipidemic activities. Prediction of toxicological properties of phytoconstituents of O. tenuiflorum did not show any major toxic effects.

Conclusion:

The hydroalcoholic extract of O. tenuiflorum showed significant anti-diabetic and anti-hyperlipidemic activity against STZ + nicotinamide induced diabetes mellitus in rats. Further studies are required to confirm the anti-diabetic and anti-hyperlipidemic activities of individual phytoconstituents of O. tenuiflorum.

Phytochemistry and bioactivity of aromatic and medicinal plants from the genus Agastache (Lamiaceae)

Agastache is a small genus of Lamiaceae, comprising 22 species of perennial aromatic medicinal herbs. In this article, we review recent advances in phytochemical, pharmacological, biotechnological and molecular research on Agastache. The phytochemical profile of all Agastache species studied to date is generally similar, consisted of two main metabolic classes-phenylpropanoids and terpenoids. In the relatively variable essential oils, most populations of different Agastache species contain over 50 % of a phenylallyl compound-estragole. Also, other volatile compounds (methyleugenol, pulegone, menthone, isomenthone and spathulenol) were reported in various proportions. Major non-volatile metabolites belong to phenolic compounds, such as caffeic acid derivatives, especially rosmarinic acid as well as several flavones and flavone glycosides like acacetin, tilianin, agastachoside, and a rare dimeric malonyl flavone (agastachin). Two unique lignans-agastenol and agastinol-were also isolated. Terpenoids include triterpenoids of oleanane-type (maslinic acid, oleanolic acid and β-amyrin), ursane-type (ursolic acid, corosolic acid and α-amyrin), and typical plant sterols, as well as abietane-type oxidized diterpenes (e.g., agastaquinone, agastol, and others). The bioactivity of various extracts or individual compounds in vitro and in vivo include antimicrobial, antiviral and anti-mutagenic activity, cytotoxic activity to cancer cell lines, and anti-nociceptive, anti-inflammatory, anti-atherogenic, antioxidant as well as biocidal activity to several foodstuff pests. Biotechnological and molecular studies have focused on in vitro propagation and enhancing the biosynthesis of bioactive metabolites in cell or organ cultures, as well as on the expression of genes involved in phenolic biosynthesis.