Antioxidant activity-guided phytochemical investigation of Artemisia gmelinii Webb. ex Stechm.: isolation and spectroscopic challenges of 3,5-O-dicaffeoyl (epi?) quinic acid and its ethyl ester

Effects of Phaffia rhodozyma on microbial community dynamics and tobacco quality during tobacco fermentation

Introduction

Carotenoids are important precursors of various aroma components in tobacco and play an important role in the sensory quality of tobacco. Phaffia rhodozyma is a species of Xanthophyllomyces capable of synthesizing a highly valuable carotenoid-astaxanthin, but has not yet been used in improving tobacco quality.

Methods

The dynamic changes of microbial community and metabolites during tobacco fermentation were analyzed in combination with microbiome and metabolome, and the quality of tobacco after fermentation was evaluated by sensory scores.

Results

P. rhodozyma could grow and produce carotenoids in tobacco extract, with a maximum biomass of 6.50 g/L and a maximum carotenoid production of 36.13 mg/L at 100 g/L tobacco extract. Meanwhile, the correlation analysis combined with microbiome and metabolomics showed that P. rhodozyma was significantly positively correlated with 11 metabolites such as 6-hydroxyluteolin and quercetin. Furthermore, the contents of alcohols, ketones and esters, which were important aromatic components in fermented tobacco, reached 77.57 μg/g, 58.28 μg/g and 73.51 μg/g, increasing 37.39%, 265.39% and 266.27% compared to the control group, respectively. Therefore, the aroma and flavor, and taste scores of fermented tobacco increased by 0.5 and 1.0 points respectively.

Discussion

This study confirmed that P. rhodozyma fermentation could effectively improve the sensory evaluation of tobacco, and provided a novel microbial fermentation method to improve tobacco quality.

Pharmacological profile of dicaffeoylquinic acids and their role in the treatment of respiratory diseases

Dicaffeoylquinic acids (DCQAs) are polyphenolic compounds found in various medicinal plants such as Echinacea species and Hedera helix, whose multi-constituent extracts are used worldwide to treat respiratory diseases. Besides triterpenes, saponins, alkamides, and other constituents, DCQAs are an important group of substances for the pharmacological activity of plant-derived extracts. Therefore, the pharmacological properties of DCQAs have been studied over the last decades, suggesting antioxidative, anti-inflammatory, antimicrobial, hypoglycaemic, cardiovascular protective, neuroprotective, and hepatoprotective effects. However, the beneficial pharmacological profile of DCQAs has not yet been linked to their use in treating respiratory diseases such as acute or even chronic bronchitis. The aim of this review was to assess the potential of DCQAs for respiratory indications based on published in vitro and in vivo pharmacological and pre-clinical data, with particular focus on antioxidative, anti-inflammatory, and respiratory-related effects such as antitussive or antispasmodic properties. A respective literature search revealed a large number of publications on the six DCQA isoforms. Based on this search, a focus was placed on 1,3-, 3,4-, 3,5-, and 4,5-DCQA, as the publications focused mainly on these isomers. Based on the available pre-clinical data, DCQAs trigger cellular mechanisms that are important in the treatment of respiratory diseases such as decreasing NF-κB activation, reducing oxidative stress, or activating the Nrf2 pathway. Taken together, these data suggest an essential role for DCQAs within herbal medicines used for the treatment of respiratory diseases and highlights the need for the identifications of DCQAs as lead substances within such extracts.

Traditional uses, Phytochemistry, Pharmacology, and Toxicology of the Genus Artemisia L. (Asteraceae): A High-value Medicinal Plant

Biologically active secondary metabolites, essential oils, and volatile compounds derived from medicinal and aromatic plants play a crucial role in promoting human health. Within the large family Asteraceae, the genus Artemisia consists of approximately 500 species. Artemisia species have a rich history in traditional medicine worldwide, offering remedies for a wide range of ailments, such as malaria, jaundice, toothache, gastrointestinal problems, wounds, inflammatory diseases, diarrhoea, menstrual pains, skin disorders, headache, and intestinal parasites. The therapeutic potential of Artemisia species is derived from a multitude of phytoconstituents, including terpenoids, phenols, flavonoids, coumarins, sesquiterpene lactones, lignans, and alkaloids that serve as active pharmaceutical ingredients (API). The remarkable antimalarial, antimicrobial, anthelmintic, antidiabetic, anti-inflammatory, anticancer, antispasmodic, antioxidative and insecticidal properties possessed by the species are attributed to these APIs. Interestingly, several commercially utilized pharmaceutical drugs, including arglabin, artemisinin, artemether, artesunate, santonin, and tarralin have also been derived from different Artemisia species. However, despite the vast medicinal potential, only a limited number of Artemisia species have been exploited commercially. Further, the available literature on traditional and pharmacological uses of Artemisia lacks comprehensive reviews. Therefore, there is an urgent need to bridge the existing knowledge gaps and provide a scientific foundation for future Artemisia research endeavours. It is in this context, the present review aims to provide a comprehensive account of the traditional uses, phytochemistry, documented biological properties and toxicity of all the species of Artemisia and offers useful insights for practitioners and researchers into underutilized species and their potential applications. This review aims to stimulate further exploration, experimentation and collaboration to fully realize the therapeutic potential of Artemisia in augmenting human health and well-being.

Identification of Chemical Compounds from Artemisia gmelinii using UPLC-QTOF-MS/MS and their Regulatory Effects on Immune Responses in DSS-Induced Colitis Mice

Artemisia gmelinii Web. ex Stechm. (AG), a popular medicinal herb in Asia, has been used as a common food ingredient in Korea and is traditionally known for its anti-inflammatory properties. Therefore, in this study, we aimed to investigate whether AG relieves IBD, a classic chronic inflammatory disease of the gastrointestinal tract. We identified 35 chemical compounds in AG ethanol extract using ultra-high-performance liquid chromatography-quadrupole time-of-flight tandem mass spectrometry. In mice with DSS-induced IBD, AG administration attenuated the disease activity index and the serum and colonic levels of inflammatory cytokines and chemokines. AG treatment decreased nuclear factor-[Formula: see text]B (NF-[Formula: see text]B) signaling, a key mediator of inflammation, in the mouse colons. Additionally, AG extract enhanced immune responses in lymphoid tissues such as spleen and Peyer's patches. Thus, AG consumption potently ameliorated IBD symptoms and improved immune signaling in lymphoid tissues.

UHPLC-DPPH method reveals antioxidant tyramine and octopamine derivatives in Celtis occidentalis

Celtis occidentalis L. (common Hackberry, Cannabaceae) has been applied in the traditional medicine for a long time as a remedy for sore throat, aid during menstruation and for treating jaundice. Nevertheless, the phytochemical exploration of the plant is still incomplete, literature data is limited to flavonoid derivatives isolated from the leaves. The present study reports screening approaches for bioactive compounds in C. occidentalis by fast and simple UHPLC-coupled assays. The UHPLC-DPPH method revealed six constituents in the methanolic extract of the twigs that had not been reported in C. occidentalis before. The antioxidant compounds were isolated by the means of flash chromatography and semi-preparative HPLC and identified by Orbitrap® MS and NMR spectroscopy as N-trans-p-coumaroyloctopamine (1), N-trans-feruloyloctopamine (2), N-trans-caffeoyltyramine (3), 2-trans-3-(4-hydroxyphenyl)-N-[2-(4-hydroxyphenyl)-2-oxoethyl] prop-2-enamide (4), N-trans-p-coumaroyltryramine (5) and N-trans-feruloyltyramine (6). Despite the high antioxidant activity measured in the present study and literature data suggesting potential positive effects of the compounds in the central nervous system, the PAMPA-BBB assay performed with the Celtis extract revealed that none of the aforementioned compounds are able to penetrate across the blood-brain barrier via transcellular passive diffusion.

Phytochemical composition of wormwood (Artemisia gmelinii) extracts in respect of their antimicrobial activity

BACKGROUND

Extracts from medicinal plants with phytochemicals with known antimicrobial properties can be an effective adjunct in the complex treatment of infectious diseases. This study aimed to evaluate the antimicrobial activity of wormwood extracts collected in Kazakhstan (Artemisia gmelinii Weber ex Stechm.), along with their phytochemical analysis.

METHODS

The ethanolic and chloroform extracts were subjected to HPLC combined with quadrupole time-of-flight mass spectrometry method. For quantitative assessment of antimicrobial activity, minimal inhibitory concentration (MIC) of the tested extracts was determined by micro-dilution broth method for the panel of the reference microorganisms. Minimal bactericidal concentration (MBC) or minimal fungicidal concentration (MFC) were also determined.

RESULTS

LC/MS analysis showed the presence of 13 compounds in the tested extracts, including flavonoids: apigenin, luteolin, rutin, two O-methylated flavonols (isorhamnetin, rhamnazine), coumarin compounds (umbelliferone, scopoletin and scopolin (scopoletin 7-glucoside), 3-hydroxycoumarin and 4-hydroxycoumarin), chlorogenic acid and two dicaffeoylquinic acid isomers. Quantitative HPLC analysis showed that umbelliferone was dominant in the chloroform extract while chlorogenic acid was identified as a main compound in the ethanolic extract. The antibacterial and antifungal activity of chloroform and ethanolic extracts was comparable. The most sensitive were the Gram-positive bacteria represented by staphylococci, Micrococcus luteus and Bacillus spp. (MIC = 1.25-5 mg/ml) and yeasts represented by Candida spp. (MIC = 2.5-5 mg/ml), irrespective of the assayed extract.

CONCLUSIONS

Extracts of wormwood Artemisia gmelinii have shown a wide spectrum of antibacterial and antifungal activity. Luteolin, rutin, isorhamnetin and scopolin were identified in A. gmelinii species for the first time. The determining of the most potential compounds of Artemisia gmelinii can be used to develop effective antibacterial and antifungal agents.

Bioactive Phenolics of the Genus Artemisia (Asteraceae): HPLC-DAD-ESI-TQ-MS/MS Profile of the Siberian Species and Their Inhibitory Potential Against α-Amylase and α-Glucosidase

Artemisia genus of Asteraceae family is a source of medicinal plants known worldwide and used as ethnopharmacological remedies for the treatment of diabetes in Northern Asia (Siberia). The aim of this study was to determine the phenolic profile of 12 Siberian Artemisia species (A. anethifolia, A. commutata, A. desertorum, A. integrifolia, A. latifolia, A. leucophylla, A. macrocephala, A. messerschmidtiana, A. palustris, A. sericea, A. tanacetifolia, A. umbrosa) and to test the efficacy of plant extracts and pure compounds for antidiabetic potential. Finally, by HPLC-DAD-ESI-TQ-MS/MS technique, 112 individual phenolic compounds were detected in Artemisia extracts in a wide range of concentrations. Some species accumulated rare plant phenolics, such as coumarin-hemiterpene ethers (lacarol derivatives) from A. latifolia and A. tanacetifolia; melilotoside from A. tanacetifolia; dihydrochalcones (davidigenin analogs) from A. palustris; chrysoeriol glucosides from A. anethifolia, A. sericea, and A. umbrosa; eriodictyol glycosides from A. messerschmidtiana; and some uncommon flavones and flavonols. The predominant phenolic group from Artemisia species herb was caffeoylquinic acid (CQAs), and in all species, the major CQAs were 5-O-CQA (20.28-127.99 μg/g) and 3,5-di-O-CQA (7.35-243.61 μg/g). In a series of in vitro bioassays, all studied Artemisia extracts showed inhibitory activity against principal enzymes of carbohydrate metabolism, such as α-amylase (IC₅₀ = 150.24-384.14 μg/mL) and α-glucosidase (IC₅₀ = 214.42-754.12 μg/mL). Although many phenolic compounds can be inhibitors, experimental evidence suggests that the CQAs were key to the biological response of Artemisia extracts. Mono-, di- and tri-substituted CQAs were assayed and showed inhibition of α-amylase and α-glucosidase, with IC₅₀ values of 40.57-172.47 μM and 61.08-1240.35 μM, respectively, and they were more effective than acarbose, a well-known enzyme inhibitor. The results obtained in this study reveal that Siberian Artemisia species and CQAs possess a pronounced inhibitory activity against α-amylase and α-glucosidase and could become a complement to synthetic antidiabetic drugs for controlling blood glucose level.

Phytochemical characterization of polyphenolic compounds with HPLC-DAD-ESI-MS and evaluation of lipid-lowering capacity of aqueous extracts from Saharan plant Anabasis aretioides (Coss & Moq.) in normal and streptozotocin-induced diabetic rats

OBJECTIVE

Anabasis aretioides (Coss & Moq.), a Saharan plant belonging to Chenopodiaceae family, is widely distributed in semi-desert areas from the Tafilalet region of Morocco. This plant is extensively used by local population against diabetes and cardiovascular disorders. The purpose of the study was to investigate the effect of the aqueous A. aretioides extract on lipid metabolism in normal and streptozotocin (STZ)-induced diabetic rats and to identify the polyphenolic compounds present. In addition, the in vitro antioxidant activity of the aqueous A. aretioides extract was also evaluated.

METHODS

The effect of an aerial part aqueous extract (APAE) of A. aretioides (5 mg/kg of lyophilized A. aretioides APAE) on plasma lipid profile was investigated in normal and STZ-induced diabetic rats (n = 6) after once daily oral administration for 15 days. The aqueous extract was tested for its 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity. Polyphenolic compounds in the extracts were definitively characterized by high-performance liquid chromatography-diode array detection-electrospray ionization-mass spectrometry.

RESULTS

In diabetic rats, oral administration of A. aretioides APAE provoked a significant decrease in both plasma cholesterol and triglyceride levels from the first to the second week (P < 0.01). A significant decrease on plasma triglyceride levels was also observed in normal rats (P < 0.01), where the reduction was 53%. In addition, the phytochemical analysis revealed the presence of 12 polyphenolic compounds. Moreover, according to the DPPH radical-scavenging activity, the aqueous extract showed an in vitro antioxidant activity.

CONCLUSION

Aqueous A. aretioides APAE exhibits lipid-lowering and in vitro antioxidant activities. Many polyphenols were present in this extract and these phytoconstituents may be involved in the pharmacological activity of this plant.

Structural Elucidation of cis/trans Dicaffeoylquinic Acid Photoisomerization Using Ion Mobility Spectrometry-Mass Spectrometry

Due to the recently uncovered health benefits and anti-HIV activities of dicaffeoylquinic acids (diCQAs), understanding their structures and functions is of great interest for drug discovery efforts. DiCQAs are analytically challenging to identify and quantify since they commonly exist as a diverse mixture of positional and geometric (cis/trans) isomers. In this work, we utilized ion mobility spectrometry coupled with mass spectrometry to separate the various isomers before and after UV irradiation. The experimental collision cross sections were then compared with theoretical structures to differentiate and identify the diCQA isomers. Our analyses found that naturally the diCQAs existed predominantly as trans/trans isomers, but after 3 h of UV irradiation, cis/cis, cis/trans, trans/cis, and trans/trans isomers were all present in the mixture. This is the first report of successful differentiation of cis/trans diCQA isomers individually, which shows the great promise of IMS coupled with theoretical calculations for determining the structure and activity relationships of different isomers in drug discovery studies.

Quantification of santonin in eight species of Artemisia from Kazakhstan by means of HPLC-UV: Method development and validation

Santonin, a powerful anthelmintic drug that was formely used to treat worms, is Artemisia cina's main constituent. However, due to its toxicity to humans, it is no longer in use. Kazakhstan is looking to introduce this plant as an anthelmintic drug for veterinary purposes, despite the known toxic properties of the santonin. The objective of this study was to develop a fast and specific method for the identification of santonin and its precise quantitation using HPLC-UV in order to avoid unnecessary intoxication, which is paramount for the development of veterinary medicines. The results obtained showed that santonin appears at around 5.7 minutes in this very reliable HPLC method. The validation of the method was performed by the investigation of parameters such as precision, accuracy, reproducibility and recovery. The method was used to identify and quantify santonin in leaves of A. scoparia, A. foetida, A. gmelinni, A. schrenkiana, A. frigida, A. sublesingiana, A terra-albae, and A. absinthium from Kazakhstan as well as in three different extracts of leaves of A. cina. This study has provided a faster and simpler method for the identification and quantification of this compound in other species of Artemisia of economic importance.

Chlorogenic acids and the acyl-quinic acids: discovery, biosynthesis, bioavailability and bioactivity

This review is focussed upon the acyl-quinic acids, the most studied group within theca.400 chlorogenic acids so far reported.

The complete chloroplast genome sequences of Artemisia gmelinii andArtemisia capillaris (Asteraceae)

In this study, complete chloroplast sequences of Artemisia gmelinii and Artemisia capillaris (the Asteraceae family), which have been used as herbal medicine in Korea, were characterized by de novo assembly with whole-genome sequence data. The genomes of A. gmelinii and A. capillaris were 151,318 bp and 151,056 bp in length, respectively. Both genomes harbored identical number of annotated genes, such as 80 protein coding genes, 4 rRNA genes and 30 tRNA genes. Phylogenetic tree revealed that both A. gmelinii and A. capillaris were closely grouped with other Artemisia species.

HPLC-DPPH Screening Method for Evaluation of Antioxidant Compounds in Corylus Species

Corylus avellana L., C. colurna L. and C. maxima Mill. have been used in traditional medicine for a long time for the treatment of various diseases, such as phlebitis, varicose veins, haemorrhoidal symptoms and eczema. Our previous studies indicated the presence of flavonol-3- O-glycosides, diarylheptanoids and caffeic acid derivatives in the bark and leaf extracts of the three species mentioned above. Comparison of in vitro DPPH scavenging activity of the Corylus extracts prepared with ethyl acetate and methanol to those of well-known antioxidant phenolics was performed. The contribution of certain compounds to the total antioxidant activity of the extracts was investigated by developing a HPLC method coupled to the DPPH radical scavenging assay.

Preferential alkali metal adduct formation by cis geometrical isomers of dicaffeoylquinic acids allows for efficient discrimination from their trans isomers during ultra-high-performance liquid chromatography/quadrupole time-of-flight mass spectrometry

RATIONALE

Caffeoylquinic acid (CQA) derivatives are a group of structurally diverse phytochemicals that have attracted attention due to their many health benefits. The structural diversity of these molecules is due in part to the presence of regio- and geometrical isomerism. This structural diversity hampers the accurate annotation of these molecules in plant extracts. Mass spectrometry (MS) is successfully used to differentiate between the different regioisomers of the CQA derivatives; however, the accurate discrimination of the geometrical isomers of these molecules has proven to be an elusive task.

METHODS

UV-irradiated methanolic solutions of diCQA were analyzed using an ultra-high-performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UHPLC/QTOFMS) method in negative ionisation mode. An in-source collision-induced dissociation (ISCID) method was optimized by varying both the capillary and cone voltages to achieve differential fragmentation patterns between UV-generated geometrical isomers of the diCQAs during MS analyses.

RESULTS

Changes in the capillary voltage did not cause a significant difference to the fragmentation patterns of the four geometrical isomers, while changes in the cone voltage resulted in significant differences in the fragmentation patterns. The results also show, for the first time, the preferential formation of alkali metal (Li(+), Na(+) and K(+)) adducts by the cis geometrical isomers of diCQAs, compared to their trans counterparts.

CONCLUSIONS

Optimized QTOFMS-based methods may be used to differentiate the geometrical isomers of diCQAs. Finally, additives such as metal salts to induce adduct formation can be applied as an alternative method to differentiate closely related isomers which could have been difficult to differentiate under normal MS settings.

Anti-melanogenic effects of Aster spathulifolius extract in UVB-exposed C57BL/6J mice and B16F10 melanoma cells through the regulation of MAPK/ERK and AKT/GSK3β signalling

OBJECTIVES

Pharmacological studies of Aster spathulifolius Maxim(AS) have demonstrated its anti-allergy, anti-viral and anti-obesity effects, however, its anti-melanogenic effects is still unclear. In this study, the effects of AS extract (ASE) on the inhibition of melanin synthesis were investigated in vitro and in vivo.

METHODS

To perform this study, the contents of melanin and tyrosinase activity were analysed in B16F10 melanoma cells. Western blotting was carried out to determine the underlyling mechanism. Additionally, we investigated the effect of this extract on hyperpigmentation in C57bL/6J mice induced by 3, 6 and 9 weeks of UVB irradiation.

KEY FINDINGS

AS extract led to reduced melanin synthesis through the regulation of MITF and its downstream signals. Furthermore, ASE increased the phosphorylation of MAPK/ERK and Akt/GSK3β signalling pathway components. In vivo study, hypopigmentation effects were also observed. The melanocyte activity and the distribution of melanin granules were decreased in UVB-irradiated mice treated with ASE.

CONCLUSIONS

These results suggest that the ASE may be promising as an active anti-melanogenic component, and further investigations should be performed regarding its potential as a whitening agent in the field of cosmetics.

Chemical composition and antioxidant activity of Tánara Ótó (Dracocephalum palmatum Stephan), a medicinal plant used by the North-Yakutian nomads

Dracocephalum palmatum Stephan (Lamiaceae) is a medicinal plant used by the North-Yakutian nomads. From the crude ethanolic extract of the aerial parts of this plant, 23 compounds (phenylpropanoids, coumarins, flavonoids, and triterpenes) were isolated. Among these, eight compounds (salvianolic acid B, caftaric acid, cichoric acid, umbelliferone, aesculetin, apigenin-7-O-β-D-glucuronopyranoside, isorhoifolin, and luteolin-4'-O-β-D-glucopyranoside) were detected for the first time in the genus Dracocephalum. Their structures were elucidated based on chemical and spectral data. The levels of most of the compounds detected in the cultivated sample were close to that of the wild sample, indicating the reproducibility of the biologically active compounds of D. palmatum through cultivation. Investigation into the biological activity of D. palmatum under in vitro conditions demonstrated that its extracts have a strong antioxidant effect due to the presence of high concentrations of phenolic compounds.