Determination of polyphenol components of Lonicera japonica Thunb. using liquid chromatography–tandem mass spectrometry: Contribution to the overall antioxidant activity

Lonicera japonica Thunb. and its characteristic component chlorogenic acid alleviated experimental colitis by promoting Lactobacillus and fecal short‐chain fatty acids production

Ulcerative colitis is intricately linked to intestinal oxidative stress and dysbiosis of the gut microbiota. Lonicera japonica Thunb. (LJ) is a traditional edible and medical flower in China, and chlorogenic acid (CGA) is one of its characteristic components. However, it remains unclear whether gut microbiota plays a role in the therapeutic effects of LJ and GCA on colitis. Here, we first observed that oral administration of LJ and CGA for 3 weeks dramatically promoted the growth of Lactobacillus and fecal short‐chain fatty acids (SCFAs) production in healthy mice. Subsequently, the alleviating effects of LJ and CGA on colitis were explored with a dextran sulfate sodium‐induced colitis mice model. The intervention of LJ and CGA notably alleviated inflammation, intestinal barrier impairment, and oxidative stress in colitis and led to a significant elevation in Lactobacillus and fecal SCFAs. Eventually, the key role of gut microbiota and their metabolites on the therapeutic effects was validated by performing fecal microbiota transplantation and sterile fecal suspensions transplantation from LJ and CGA‐treated healthy mice to colitis mice. Our findings demonstrated that consumption of LJ and CGA could benefit the host both in healthy condition and colitis. The beneficial effects were attributed to the improvement of the endogenous antioxidant system and promotion of the probiotic Lactobacillus and SCFAs production. Our study highlighted the great potential of LJ and CGA to be consumed as functional foods and provided novel mechanisms by which they alleviated colitis.

Quantitative analysis of the quality constituents of Lonicera japonica Thunberg based on Raman spectroscopy

Quantitative analysis of the quality constituents of Lonicera japonica (Jinyinhua [JYH]) using a feasible method provides important information on its evaluation and applications. Limitations of sample pretreatment, experimental site, and analysis time should be considered when identifying new methods. In response to these considerations, Raman spectroscopy combined with deep learning was used to establish a quantitative analysis model to determine the quality of JYH. Chlorogenic acid and total flavonoids were identified as analysis targets via network pharmacology. High performance liquid chromatograph and ultraviolet spectroscopy were used to construct standard curves for quantitative analysis. Raman spectra of JYH extracts (1200) were collected. Subsequently, models were built using partial least squares regression, Support Vector Machine, Back Propagation Neural Network, and One-dimensional Convolutional Neural Network (1D-CNN). Among these, the 1D-CNN model showed superior prediction capability and had higher accuracy (R2 = 0.971), and lower root mean square error, indicating its suitability for rapid quantitative analysis.

Lonicerae Japonicae Caulis: a review of its research progress of active metabolites and pharmacological effects

Lonicerae Japonicae Caulis is the aboveground stem part of the Lonicera Japonica Thunb, which belongs to the medicine food homology species in China. It has the effects of clearing away heat, toxic material, dredging wind and unblocking collaterals. Modern research shows that it contains various active metabolites and a wide range of pharmacological effects, which is of great research and clinical application value. It mainly contains organic acids, volatile oils, flavonoids, triterpenes, triterpene saponins and other active metabolites. Its pharmacological effects mainly include anti-inflammatory, antibacterial, antitumor, antioxidant, and repairing bone and soft tissue. Based on the literature reports in recent years, the active metabolites, pharmacological effects and mechanisms of Lonicerae Japonicae Caulis were sorted out and summarized. It lays a foundation for explaining the efficacy material basis and application value of Lonicerae Japonicae Caulis. It aims to provide a reference for the in-depth research, development and utilization of Lonicerae Japonicae Caulis.

Rapid screening of neuraminidase inhibitors using an at-line nanofractionation platform involving parallel oseltamivir-sensitive/resistant neuraminidase bioassays

In this study, an advanced at-line nanofractionation based screening platform was developed to screen potential neuraminidase inhibitors (NAIs) from Lonicera japonica Thunb by involving two parallel bioassays, for determining both oseltamivir-sensitive neuraminidase (NAS) and oseltamivir-resistant neuraminidase (NAR) inhibitory activities. 20 potential NAIs with both NAS and NAR inhibitory effects were screened from Lonicera japonica Thunb and identified by mass spectrometer, including 11 phenolic acids, 8 flavonoids and one iridoid glycoside. The proposed at-line nanofractionation based screening platform for NAIs was also used to rapidly screen nine batches of water extracts of Lonicera japonica Thunb or its similar species. Clear differences in the number and content of active components were easily observed, demonstrating that the proposed method possesses great potential for the quality control of herb medicines.

Bioactive constituents from the leaves of Lonicera japonica

Six new isolates including three new alkaloids (1-3), one new secoiridoid glycoside (4) and one new 11-delactonization-secoiridoid glycoside (5), and one new organic acid (6) were identified from the leaves of Lonicera japonica, among which 1 and 2 assigned as a pair of configurational isomers possessed two oxazolidin-2-one fragments connected through NN bond. The structures were elucidated by the NMR data and ICD analysis. All the compounds (1-6) were tested for their antioxidant and hepatoprotective activities using cell models of ABAP-induced HepG₂ cell and APAP-induced HepG₂ cell by the MTT method. Outstandingly, compound 2 exhibited remarkable antioxidative activity with inhibitory rate of 117.2%, and compounds 2, 4, 6 exhibited significant effects with inhibitory rates of 68.1%, 69.3%, 69.2%, respectively.

Characterization of Silver Nanoparticles Synthesized by Leaves of Lonicera japonica Thunb

Background

The leaves of L. japonica (LLJ) are widely used as medicine in China. It is rich in caffeoylquinic acids, flavonoids and iridoid glycosides and has strong reducing capacities. Therefore, it can be used as a green material to synthesize silver nanoparticles.

Methods

LLJ was used as a reducing agent to produce the LLJ-mediated silver nanoparticles (LLJ-AgNPs). The structure and physicochemical properties of LLJ-AgNPs were characterized by ultraviolet spectroscopy (UV-Vis), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), and x-ray powder diffraction (XRD). Antioxidant activity of LLJ-AgNPs was determined by 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging. Antibacterial activity was determined by 96 well plates (AGAR) gradient dilution, while the anticancer potential was determined by MTT assay.

Results

The results showed LLJ-AgNPs had a spherical structure with the maximum UV-Vis absorption at 400 nm. In addition, LLJ-AgNPs exhibited excellent antioxidant properties, where the free radical scavenging rate of LLJ-AgNPs was increased from 39% to 92% at concentrations from 0.25 to 1.0 mg/mL. Moreover, LLJ-AgNPs displayed excellent antibacterial properties against E. coli and Salmonella at room temperature, with minimum inhibitory values of 10-6 and 10-5 g/L, respectively. In addition, the synthetic LLJ-AgNPs exhibited a better inhibition effect in the proliferation of cancer cells (HepG2, MDA-MB -231, and Hela cells).

Conclusion

The present study provides a green approach to synthesize LLJ-AgNPs. All those findings illustrated that the produced LLJ-AgNPs can be used as an economical and efficient functional material for further applications in food and pharmaceutical fields.

Flavonoids: The Innocuous Agents Offering Protection Against Alzheimer's Disease Through Modulation Of Proinflammatory And Apoptotic Pathways

BACKGROUND

Beginning from mild cognitive impairment in patients suffering from Alzheimer's disease (AD), dementia sets in with the progress of the disease. The pathological changes in the brain begin fifteen to twenty years before AD related dementia develops. Presence of senile plaques and neurofibrillary tangles are considered the hallmarks of AD brain. Chronic inflammation resulting from the disruption of equilibrium between anti-inflammatory and pro-inflammatory signalling emerges as another important feature of AD and also other neurodegenerative diseases. Substantial studies demonstrate that this sustained immune response in the brain is associated with neuronal loss, along with facilitation and aggravation of Aβ and NFT pathologies. Although it is well accepted that neuroinflammation and oxidative stress have both detrimental and beneficial influences on the brain tissues, the involvement of microglia and astrocytes in the onset and progress of the neurodegenerative process in AD is becoming increasingly recognized. The cause of neuronal loss, although, is known to be apoptosis, the mechanism of promotion of neuronal death remains undisclosed.

OBJECTIVE

Controlling the activation of the resident immune cells and/or the excessive production of pro-inflammatory and pro-oxidant factors could be effective as therapeutics. Among the phytonutrients, the neuroprotective role of flavonoids is beyond doubt. This review is an exploration of literature on the role of flavonoids in these aspects.

CONCLUSION

Flavonoids are not only effective in ameliorating the adverse consequences of oxidative stress but also impede the development of late onset Alzheimer's disease by modulating affected signalling pathways and boosting signalling crosstalk.

Natural biflavones are potent inhibitors against SARS-CoV-2 papain-like protease

Papain-like protease (PL^pro) is a key enzyme encoded by SARS-CoV-2 that is essential for viral replication and immune evasion. Significant suppression of viral spread and promotion of antiviral immunity can be achieved by inhibition of PL^pro, revealing an inspiring strategy for COVID-19 treatment. This study aimed to discover PL^pro inhibitors by investigating the national compound library of traditional Chinese medicines (NCLTCMs), a phytochemical library comprising over 9000 TCM-derived compounds. Through virtual screening and enzymatic evaluations, nine natural biflavones were confirmed to be effective PL^pro inhibitors with IC₅₀ values ranging from 9.5 to 43.2 μM. Pro-ISG15 cleavage assays further demonstrated that several biflavones exhibited potent inhibitory effects against PL^pro-mediated deISGylation, a key process involved in viral immune evasion. Herein, we report the discovery, antiviral evaluation, structure-activity relationship elucidation and molecular docking investigation of biflavones as potent inhibitors of SARS-CoV-2 PL^pro.

Potential Application of Lonicera japonica Extracts in Animal Production: From the Perspective of Intestinal Health

Lonicera japonica (L. japonica) extract is rich in active substances, such as phenolic acids, essential oils, flavones, saponins, and iridoids, which have a broad spectrum of antioxidant, anti-inflammatory, and anti-microbial effect. Previous studies have demonstrated that L. japonica has a good regulatory effect on animal intestinal health, which can be used as a potential antibiotic substitute product. However, previous studies about intestinal health regulation mainly focus on experimental animals or cells, like mice, rats, HMC-1 Cells, and RAW 264.7 cells. In this review, the intestinal health benefits including antioxidant, anti-inflammatory, and antimicrobial activity, and its potential application in animal production were summarized. Through this review, we can see that the effects and mechanism of L. japonica extract on intestinal health regulation of farm and aquatic animals are still rare and unclear. Further studies could focus on the regulatory mechanism of L. japonica extract on intestinal health especially the protective effects of L. japonica extract on oxidative injury, inflammation, and regulation of intestinal flora in farm animals and aquatic animals, thereby providing references for the rational utilization and application of L. japonica and its extracts in animal production.

Antioxidant and anticancer potentials of edible flowers: where do we stand?

Edible flowers are attracting special therapeutic attention and their administration is on the rise. Edible flowers play pivotal modulatory roles on oxidative stress and related interconnected apoptotic/inflammatory pathways toward the treatment of cancer. In this review, we highlighted the phytochemical content and therapeutic applications of edible flowers, as well as their modulatory potential on the oxidative stress pathways and apoptotic/inflammatory mediators, resulting in anticancer effects. Edible flowers are promising sources of phytochemicals (e.g., phenolic compounds, carotenoids, terpenoids) with several therapeutic effects. They possess anti-inflammatory, anti-diabetic, anti-microbial, anti-depressant, anxiolytic, anti-obesity, cardioprotective, and neuroprotective effects. Edible flowers potentially modulate oxidative stress by targeting erythroid nuclear transcription factor-2/extracellular signal-regulated kinase/mitogen-activated protein kinase (Nrf2/ERK/MAPK), reactive oxygen species (ROS), nitric oxide (NO), malondialdehyde (MDA) and antioxidant response elements (AREs). As the interconnected pathways to oxidative stress, inflammatory mediators, including tumor necrosis factor (TNF)-α, nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), interleukins (ILs) as well as apoptotic pathways such as Bcl-2-associated X protein (Bax), Bcl-2, caspase and cytochrome C are critical targets of edible flowers in combating cancer. In this regard, edible flowers could play promising anticancer effects by targeting oxidative stress and downstream dysregulated pathways.

Variations in morphology, physiology, and multiple bioactive constituents of Lonicerae Japonicae Flos under salt stress

Lonicerae Japonicae Flos (LJF) is an important traditional Chinese medicine for the treatment of various ailments and plays a vital role in improving global human health. However, as unable to escape from adversity, the quality of sessile organisms is dramatically affected by salt stress. To systematically explore the quality formation of LJF in morphology, physiology, and bioactive constituents' response to multiple levels of salt stress, UFLC-QTRAP-MS/MS and multivariate statistical analysis were performed. Lonicera japonica Thunb. was planted in pots and placed in the field, then harvested after 35 days under salt stress. Indexes of growth, photosynthetic pigments, osmolytes, lipid peroxidation, and antioxidant enzymes were identified to evaluate the salt tolerance in LJF under different salt stresses (0, 100, 200, and 300 mM NaCl). Then, the total accumulation and dynamic variation of 47 bioactive constituents were quantitated. Finally, Partial least squares discrimination analysis and gray relational analysis were performed to systematically cluster, distinguish, and evaluate the samples, respectively. The results showed that 100 mM NaCl induced growth, photosynthetic, antioxidant activities, osmolytes, lipid peroxidation, and multiple bioactive constituents in LJF, which possessed the best quality. Additionally, a positive correlation was found between the accumulation of phenolic acids with antioxidant enzyme activity under salt stress, further confirming that phenolic acids could reduce oxidative damage. This study provides insight into the quality formation and valuable information to improve the LJF medicinal value under salt stress.

Optimization for the extraction of polyphenols from Inonotus obliquus and its antioxidation activity

In order to study the extraction process and antioxidative activity of Inonotus obliquus polyphenols (IOP), the optimal extraction process was determined by orthogonal experiment optimization. The clearance rate of DPPH and hydroxyl radicals were used as indicators to evaluate the antioxidant activity of IOP. The results showed that the optimum extraction conditions were as follows: ethanol concentration of 50%, solid-liquid ratio of 1:20, temperature of 60 °C, and 90 min. Under these conditions, the extraction yield of IOP was 2.84%. The antioxidant capacity of extracts appeared to be IOP dose-dependent, while it also presented stronger ferric reducing antioxidant power (FRAP). High Performance Liquid Chromatography (HPLC-MS) analysis indicated that the major identified polyphenol compounds extracted at the optimal conditions were ten compounds (procyanidin, caffeic acid, p-coumaric acid, isorhamnetin-3-O-glucoside, astilbin, tangeretin, gallic acid, kaempferol, quercetin, and catechin 7-xyloside). These findings indicate that I. obliquus polyphenols have the potential to be developed as a natural antioxidant and have a good application prospect.

Healthspan Improvements in Caenorhabditis elegans with Traditional Chinese Herbal Tea

Searching for natural and safe herbal tea with health benefits has attracted more and more attention, which is of great significance for reducing disease risk. A Chinese traditional herbal tea (HT) is rich in active ingredients extracted from natural plants. Numerous pharmacological studies showed that HT had the potential to improve health, including antidepression and antioxidant effects. In this study, we proposed a strategy to explore the role and underlying mechanism of HT in improving healthspan of a Caenorhabditis elegans model. First, we found that HT significantly prolonged the lifespan without reducing fertility in worms. Second, stress resistance (oxidative stress and heat stress) was enhanced and Aβ- and polyQ-induced toxicity was relieved significantly by HT treatment. Both fat deposition and age pigment accumulation were found to be significantly reduced in HT-treated worms. The locomotion in mid-late stages was improved, indicating that behavioral mobility was also significantly enhanced. Furthermore, the main components of HT were eighteen polyphenols and two terpenoids. Finally, it was found that this protective mechanism was positively correlated with the insulin/insulin-like growth factor signaling- (IIS-) dependent manner, which went through promoting the nuclear localization of DAF-16 and its downstream SOD-3 expression. These results suggested that HT had an important role in improving health, which might serve as a promising healthy tea.

A comprehensive study of the aerial parts of Lonicera japonica Thunb. based on metabolite profiling coupled with PLS-DA

INTRODUCTION

Lonicera japonica Thunb. is an economically important species of honeysuckle belonging to the Caprifoliaceae family. All aerial parts of L. japonica (leaf, flower bud, flower, and caulis) are used as herbal remedies in traditional Chinese medicine. The application of plant metabolomics to the study of L. japonica provides the potential for identifying the phytochemical composition and useful chemical markers of the plant.

OBJECTIVE

To develop a strategy integrating metabolic profiling and partial least squares discriminant analysis (PLS-DA) to separate the aerial parts of L. japonica based on the occurrence of chemical markers.

METHODOLOGY

The two-part strategy consisted of (1) ultra-fast liquid chromatography coupled with triple quadrupole-time of flight tandem mass spectrometry (UFLC-triple TOF-MS/MS), (2) PLS-DA, which was applied to distinguish between the different aerial parts and reveal their differential characteristic metabolites.

RESULTS

A total of 71 metabolites were identified from samples, and eight candidate compounds were identified (lonicerin, kaempferol-3-O-rutinoside, loganin, isochlorogenic acid B, isochlorogenic acid C, secologanic acid, luteoloside, astragalin) as optimal chemical markers based on variable importance in projection (VIP) and p-value. The relative contents of eight candidate compounds were compared based on their peak intensities.

CONCLUSION

This study established an efficient strategy for exploring metabolite profiling and defining chemical markers among the different aerial parts of L. japonica, and laid the foundation for elucidating the phytochemical differences in efficacy between Lonicerae Japonicae Flos (LJF) and Lonicerae Japonicae Caulis (LJC). Our findings also indicate that the leaves of L. japonica leaf could be used as an alternative medicinal resource for LJF and provide a reference for comprehensive exploitation and utilisation of L. japonica resources.

Comparison of chemical constitution and bioactivity among different parts of Lonicera japonica Thunb

BACKGROUND

Lonicera japonica Thunb is a common herb in East Asia. The flower buds are usually regarded as the traditional medicinal part, while leaves and stems are considered less valuable and receive little attention. This study compared the chemical constituents and anti-inflammatory effects of the different tissues in L. japonica Thunb for the first time.

RESULTS

Thirty compounds were identified by ultra-performance liquid chromatography-photodiode detector-quadrupole / time of flight-mass spectrometry (UPLC-PDA-Q/TOF-MS/MS) analysis. Hydroxycinnamic acids, flavonoids, and iridoids were identified as the major components. The flower buds (FLJ), leaves (LLJ), and stems (SLJ) of L. japonica Thunb showed strong similarities in chemical components. The LLJ contained higher levels of hydroxycinnamic acids and flavonoids than the FLJ and SLJ. Furthermore, FLJ, LLJ, and SLJ exhibited potent anti-inflammatory activity in croton oil-induced ear edema and carrageenan-induced paw edema assays in mice. Moreover, FLJ, LLJ, and SLJ showed a cytoprotective effect on lipopolysaccharide- (LPS-) stimulated RAW 264.7 macrophages. Lipopolysaccharide-induced increases in nitric oxide (NO), tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and interleukin-6 (IL-6) were suppressed by treatments of FLJ, LLJ, and SLJ, respectively. The LLJ possessed a stronger anti-inflammatory effect than the FLJ.

CONCLUSION

Leaves and stems of L. japonica Thunb have chemical components and anti-inflammatory properties similar to flower buds, and may become alternative or supplementary sources of flower buds. © 2019 Society of Chemical Industry.

Lonicerae japonicae flos and Lonicerae flos: a systematic review of ethnopharmacology, phytochemistry and pharmacology

Lonicerae japonicae flos (called Jinyinhua, JYH in Chinese), flowers or flower buds of Lonicera japonica Thunberg, is an extremely used traditional edible-medicinal herb. Pharmacological studies have already proved JYH ideal clinical therapeutic effects on inflammation and infectious diseases and prominent effects on multiple targets in vitro and in vivo, such as pro-inflammatory protein inducible nitric oxide synthase, toll-like receptor 4, interleukin-1 receptor. JYH and Lonicerae flos [called Shanyinhua, SYH in Chinese, flowers or flower buds of Lonicera hypoglauca Miquel, Lonicera confusa De Candolle or Lonicera macrantha (D.Don) Spreng] which belongs to the same family of JYH were once recorded as same herb in multiple versions of Chinese Pharmacopoeia (ChP). However, they were listed as two different herbs in 2005 Edition ChP, leading to endless controversy since they have close proximity on plant species, appearances and functions, together with traditional applications. In the past decades, there has no literature regarding to systematical comparison on the similarity concerning research achievements of the two herbs. This review comprehensively presents similarities and differences between JYH and SYH retrospectively, particularly proposing them the marked differences in botanies, phytochemistry and pharmacological activities which can be used as evidence of separate list of JYH and SYH. Furthermore, deficiencies on present studies have also been discussed so as to further research could use for reference.

De novo transcriptomic analysis of light-induced flavonoid pathway, transcription factors in the flower buds of Lonicera japonica

KEY MESSAGE

Transcriptomic analysis of the relationship between gene expression patterns and flavonoid contents in the flower buds of Lonicera japonica under light-induced conditions, especially the flavonoid pathway genes and transcription factors.

ABSTRACT

Flos Lonicerae Japonicae (FLJ), the flower buds of Lonicera japonica Thunb., has been used to treat some human diseases including severe respiratory syndromes and hand-foot-and-mouth diseases owing to its putative antibacterial, and antiviral effects. Luteoloside is a flavonoid that is used by the Chinese Pharmacopoeia to evaluate the quality of FLJ. Light is an important environmental factor that affects flavonoid biosynthesis in the flower buds of L. japonica. However, how light triggers increases in flavonoid production remains unclear. To enhance our understanding of the mechanism involved in light-regulated flavonoid biosynthesis, we sequenced the transcriptomes of L. japonica exposed to three different light conditions: 100% light intensity (CK), 50% light intensity (LI50), and 25% light intensity (LI25) using an Illumina HiSeq 4000 System. A total of 77,297 unigenes with an average length of 809 bp were obtained. Among them, 43,334 unigenes (56.06%) could be matched to at least one biomolecular database. Additionally, 4188, 1545 and 1023 differentially expressed genes (DEGs) were identified by comparative transcriptomics LI25-vs-CK, LI50-vs-CK, and LI25-vs-LI50, respectively. Of note, genes known to be involved in flavonoid biosynthesis, such as 4-coumarate coenzyme A ligase (4CL), and chalcone synthase (CHS) were up-regulated. In addition, a total of 1649 transcription factors (TFs) were identified and divided into 58 TF families; 98 TFs exhibited highly dynamic changes in response to light intensity. Quantitative real-time PCR (qRT-PCR) was used to test the expression profiles of the RNA sequencing (RNA-Seq) data. This study offers insight into how transcriptional expression pattern is influenced by light in the flower buds of L. japonica, and will enhance the understanding of molecular mechanisms of flavonoid biosynthesis in response to light in L. japonica.

Identification and evaluation of Lonicera japonica flos introduced to the Hailuogou area based on ITS sequences and active compounds

Lonicera japonica flos (LJF), the dried flower buds of L. japonica Thunb., have been used in traditional Chinese herbal medicine for thousands of years. Recent studies have reported that LJF has many medicinal properties because of its antioxidative, hypoglycemic, hypolipidemic, anti-allergic, anti-inflammatory, and antibacterial effects. LJF is widely used in China in foods and healthcare products, and is contained in more than 30% of current traditional Chinese medicine prescriptions. Because of this, many Chinese villages cultivate LJF instead of traditional crops due to its high commercial value in the herbal medicine market. Since 2005, the flower buds of L. japonica are the only original LJF parts considered according to the Chinese Pharmacopoeia of the People's Republic of China. However, for historical and commercial reasons, some closely related species of Lonicera Linn. continue to be mislabeled and used as LJF. Currently, there are hundreds of commercial varieties of LJF on the market and it is difficult to choose fine LJF varieties to cultivate. In this study, a total of 21 varieties labeled as LJF on the market were planted in the Hailuogou area. In order to choose the optimum variety, internal transcribed spacer (ITS) sequence alignment analysis was used to test whether the 21 varieties were genuine LJF or not. Cluster analysis of active components based on the content of chlorogenic acid and luteoloside in flower buds, stems and leaves was used to evaluate the quality of the varieties. Results demonstrated that four of the varieties were L. macranthoides Hand.-Mazz., while the other 17 varieties were L. japonica, and genuine LJF. The ITS sequence analysis was proven to be highly effective in identifying LJF and Lonicerae flos. Among the 17 L. japonica varieties, the amounts of chlorogenic acid and luteoloside in flower buds, stems and leaves were significantly different. Based on the cluster analysis method, the variety H11 was observed to have the highest level of active components, and is therefore recommended for large-scale planting in the Hailuogou area.

Comparison of Multiple Bioactive Constituents in the Flower and the Caulis of Lonicera japonica Based on UFLC-QTRAP-MS/MS Combined with Multivariate Statistical Analysis

Lonicerae japonicae flos (LJF) and Lonicerae japonicae caulis (LJC) are derived from different parts of Lonicera japonica Thunb. (Caprifoliaceae), and have been used as herbal remedies to treat various diseases for thousands of years with confirmed curative effects. However, little attention has been paid to illustrating the differences in efficacy from the perspective of phytochemistry. In the present study, a simultaneous determination of 47 bioactive constituents, including 12 organic acids, 12 flavonoids, six iridoids, 13 amino acids and four nucleosides in 44 batches of LJF and LJC samples from different habitats and commercial herbs was established based on ultra-fast liquid chromatography tandem triple quadrupole mass spectrometry (UFLC-QTRAP-MS/MS). Moreover, principal component analysis (PCA), partial least squares discriminant analysis (PLS-DA) and t-test were then performed to classify and reveal the differential compositions of LJF and LJC according to the content of the tested constituents. The results demonstrated that the types and contents of chemical components (e.g., isochlorogenic acid A, chlorogenic acid, neochlorogenic acid, quinic acid, secologanic acid, luteoloside, loganin, secoxyloganin, morroniside and L-isoleucine) were significantly different, which may lead to the classification and the differences in efficacy of LJF and LJC. Our findings not only provide a basis for the comprehensive evaluation and intrinsic quality control of LJF and LJC, but also pave the way for discovering the material basis contributing to the different properties and efficacies of the two medicinal materials at the phytochemical level.

A Biosensor-Based Quantitative Analysis System of Major Active Ingredients in Lonicera japonica Thunb. Using UPLC-QDa and Chemometric Analysis

In the study, a surface plasmon resonance-based (SPR-based) competitive assay was performed to analyze different compounds’ inhibitory activity to TNF-α, an important pro-inflammatory cytokine in the pathogenesis of chronic inflammatory diseases. Moreover, the single mass spectrometry (MS) detection method was coupled with an ultra-high-performance liquid chromatography (UPLC) system for the routine quality control (QC) of a traditional Chinese medicine (TCM). The above quality control strategy was evaluated with Lonicera japonica Thunb. Analytes were firstly separated on a Waters ACQUITYTM UPLC HSS T3 column (2.1 × 50 mm; particle size = 1.8 μm) using a 0.1% formic acid gradient elution, then detected by negative ESI mass spectrometry. The limits of quantification (LOQ) for analytes reached 0.005–0.56 μg/mL. The LOD of the QDa detector was lower than that of the PDA detector, indicating its wider detection range. The QDa detector was also more suitable for the analysis of the complex matrix of TCM. The method showed excellent linearity, with regression coefficients higher than 0.9991. The average recoveries of the investigated analytes were in the range of 98.78–105.13%, with an RSD below 3.91%. The inter-day precision range (n = 3 days) was 2.51–4.54%. Compared to other detectors, this strategy could be widely applied in the quantitative analysis of TCM. In addition, the chemically latent data could be revealed using chemometric analysis. Importantly, this study provides an efficient screening method for small-molecule inhibitors targeting the TNF-α pathway.

Extraction optimization, antioxidant activity, and tyrosinase inhibitory capacity of polyphenols from Lonicera japonica

The objective of this research was twofold: first, to optimize the extraction process of Lonicera japonica polyphenols using a response surface methodology, and second, to study the antioxidant activity and tyrosinase inhibitory capacity of the polyphenols of different purities. High-speed shearing homogenization extraction was used to extract the polyphenols from L. japonica. The antioxidant activity and the effect of polyphenols on tyrosinase activity were studied using free radical scavenging assay and the tyrosinase method, respectively. The optimal extraction conditions with an extraction yield of 6.96% for polyphenols were determined as follows: ethanol volume fraction 57%, shearing time 3.30 min, and solid-liquid ratio 1:58. Lonicera japonica polyphenols exhibited potent scavenging activity on 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2, 2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), and inhibitory capacity on tyrosinase. The results suggested that L. japonica polyphenols could be explored as a natural antioxidant and tyrosinase inhibitor.

Fatty acids-based microemulsion liquid chromatographic determination of multiple caffeoylquinic acid isomers and caffeic acid in honeysuckle sample

A green and efficient microemulsion liquid chromatographic (MELC) method using fatty acid as co-surfactant and electrochemical detection was established and validated for the determination of four caffeoylquinic acid isomers and caffeic acid in honeysuckle samples. The influences of each individual component within the isocratic oil-in-water (O/W) microemulsion mobile phase were systematically investigated, such as the type and concentration of co-surfactant, concentration of sodium dodecyl sulphate (SDS), organic modifier addition, type and concentration of oil phase, pH and detection voltage. Results indicated that excellent resolution was achieved using 3.0% w/v of propionic acid, 0.5% w/v of ethyl acetate, 1.0% w/v of SDS, 5% w/v acetonitrile, 90.5% v/v of water and 25 mM sodium dihydrogen phosphate at pH = 3 as microemulsion mobile phase and 0.8 V as the optimal voltage value. Under the optimal condition, analytical performance of developed method was evaluated. The detection limits were below 17.3 ng/mL and intra-day and inter-day precisions by relative standard deviations (RSD%) were between 0.5% and 3.6%. Satisfactory recovery (in the range of 83.8-109.1%) with good repeatability lower than 4.7% (n = 3) was obtained. Therefore, the developed O/W MELC method was rapid, precise and accurate for simultaneous determination of neochlorogenic acid, chlorogenic acid, isochlorogenic acid A and isochlorogenic acid C in honeysuckle samples, with contents of 2.6, 28.7, 18.1 and 5.2 mg/g, respectively.

Development of a colloidal gold-based lateral flow dipstick immunoassay for rapid detection of chlorogenic acid and luteoloside in Flos Lonicerae Japonicae

Flos Lonicerae Japonicae (FLJ), known as golden-and-silver honeysuckle, is a widely used Chinese herbal medicine with pharmacological activities and edibleness in China. Chlorogenic acid (CGA) and luteoloside are the quality control markers of FLJ regulated by the Chinese Pharmacopoeia (2015 edition). For rapid evaluation of the quality of FLJ, dipsticks for CGA and luteoloside detection were developed. The detection limit of the dipsticks for CGA and luteoloside, defined as the lowest concentration of the target analyte between which the test line was invisible, were 100 ng/mL and 200 ng/mL, respectively. The dipsticks were used for determination of CGA and luteoloside contents in FLJ, and the results were confirmed by high-performance liquid chromatography. The developed dipsticks, with their simplicity of use, lack of dependence on instruments and environmental friendliness, could be used to evaluate the quality of FLJ within 10 min.

Comparison of Free, Esterified, and Insoluble-Bound Phenolics and Their Bioactivities in Three Organs of Lonicera japonica and L. macranthoides

Dried flower buds of Lonicera japonica and L. macranthoides have long been used as herbs in numerous Chinese traditional medicines. Comparisons of three phenolic fractions (i.e., free, esterified, and insoluble-bound phenolics) in three different organs (i.e., flower, leaf, and stem) of the two species revealed that the free phenolics were the highest in terms of total phenol and total flavonoid content, composed of the most numerous phenolics and flavonoids; thus, they exhibited the most excellent antioxidant activities (2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonate) (ABTS), and oxygen radical absorbance capacity (ORAC)), as well as protective effects on DNA damage induced by free radicals. In identical free and esterified phenolics of a same organ, higher contents and bioactivities were observed in L. macranthoides than in L. japonica. Phenolics identified by ultra-performance liquid chromatography with a diode array detector, alongside tandem mass spectrometry coupled with a quadrupole time-of-flight mass spectrometer (UPLC-DAD⁻QTOF-MS/MS) mainly included chlorogenic acid and its five derivatives, three flavonoids that were only found in the free phenolic fraction and closely correlated with its bioactivity, and caffeic acid that was the major contributor to antioxidant activity of the esterified and insoluble-bound phenolic fractions. It was, thus, concluded that, like L. japonica, L. macranthoides, which was underestimated since being separately listed by the 2010 edition of the Chinese Pharmacopoeia, is also a good (and better) herbal medicine.

Correlation of the temporal and spatial expression patterns of HQT with the biosynthesis and accumulation of chlorogenic acid in Lonicera japonica flowers

Hydroxycinnamoyl-CoA quinate transferase (HQT) is one of the key enzymes in the biosynthesis of chlorogenic acid (CGA) in the flowers of Lonicera japonica. However, the spatiotemporal expression patterns of HQT and its relationship to the dynamics of CGA biosynthesis, transport, and storage remain largely unknown. In this study, we collected L. japonica flower samples at different growth stages (S1-S6) and examined the spatiotemporal expression pattern of HQT and the dynamic accumulation patterns of CGA using a combination of molecular and cytological techniques. Our results suggest that the spatiotemporal expression pattern of HQT is directly correlated with dynamic changes in CGA accumulation and distribution in L. japonica flowers. We further show that CGA is synthesized primarily in the cytoplasm and chloroplasts. CGA synthesized in the cytoplasm first accumulates in specialized vesicles and is then transferred to large central vacuoles for storage by fusion of CGA-containing vesicles with vacuoles. Furthermore, CGA synthesized in the chloroplasts appears to be transferred into the vacuoles for storage by direct membrane fusion between the tonoplast and the disrupted chloroplast membranes. Collectively, our results suggest that CGA is synthesized in chloroplasts and cytoplasm and finally transferred to the vacuole for long-term storage.

Novel caffeoylquinic acid derivatives from Lonicera japonica Thunb. flower buds exert pronounced anti-HBV activities

Lonicera japonica Thunb., possesses antiviral and hepatoprotective activities, and is widely used as a health food and in cosmetics. However, its major constituents, caffeoylquinic acid derivatives, and their anti-HBV activity were lacking systematic research. In this study, four novel caffeoylquinic acids, five simple caffeic acids and fourteen known caffeoylquinic acids are isolated and identified from L. japonica. Most caffeoylquinic acids inhibited HBsAg and HBeAg secretion, and HBV DNA replication. In particular, 100 μg ml⁻¹ monocaffeoylquinic acid 9 inhibits HBsAg and HBeAg secretion, and HBV DNA replication by 83.82, 70.76 and 39.36% compared to the control. Unfortunately, 50 μg ml⁻¹ tricaffeoylquinic acid 23 promotes HBsAg and HBeAg secretion, and HBV DNA replication by 172.39, 9.92 and 55.40%. Finally, structure–activity relationships reveal that caffeoylquinic acids containing a caffeoyl group have better inhibitory activities. The results indicate that caffeoylquinic acids from L. japonica could serve as anti-HBV agents for functional food or medicinal use.

Lonicera japonica Thunb., possesses antiviral and hepatoprotective activities, and is widely used as a health food and in cosmetics.

LC-MS/MS characterization, anti-inflammatory effects and antioxidant activities of polyphenols from different tissues of Korean Petasites japonicus (Meowi)

The Korean Petasites japonicus is a perennial plant used in folk medicine as a remedy for many diseases and popularly consumed as spring greens. Ten polyphenols were characterized from the leaves, stems and roots of this plant via high-performance liquid chromatography-tandem mass spectrometry. Individual polyphenols were quantified for the first time using calibration curves of six structurally related external standards. Validation data indicated that coefficients of determinations (R² ) were ≥0.9702 for all standards. Recoveries measured at 50 and 100 mg/L were 80.0-91.9 and 80.3-105.3%, respectively. Precisions at these two concentration levels were 0.7-6.1 and 1.1-5.5%, respectively. The total number of identified components was largest for the leaves and smallest for the stems. The leaf and root polyphenolic extracts showed anti-inflammatory effects by inducing LPS-activated COX-2 and iNOS protein levels in mouse macrophage RAW 264.7 cells. The antioxidant capacity of the polyphenols, when evaluated for DPPH (α,α-diphenyl-β-picrylhydrazyl)^ˑ , ABTS⁺ [2-2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)] and superoxide radical scavenging activities, and in ferric reducing ability of plasma (FRAP) assays, was highest in the leaf and lowest in the stem. This trend suggests that the antioxidant capacities depend primarily on polyphenol concentration in each tissue. The current findings suggest that polyphenols derived from P. japonicas tissues could have potential as functional health foods.

DNA Methylation Influences Chlorogenic Acid Biosynthesis in Lonicera japonica by Mediating LjbZIP8 to Regulate Phenylalanine Ammonia-Lyase 2 Expression

The content of active compounds differ in buds and flowers of Lonicera japonica (FLJ) and L. japonica var. chinensis (rFLJ). Chlorogenic acid (CGAs) were major active compounds of L. japonica and regarded as measurements for quality evaluation. However, little is known concerning the formation of active compounds at the molecular level. We quantified the major CGAs in FLJ and rFLJ, and found the concentrations of CGAs were higher in the buds of rFLJ than those of FLJ. Further analysis of CpG methylation of CGAs biosynthesis genes showed differences between FLJ and rFLJ in the 5'-UTR of phenylalanine ammonia-lyase 2 (PAL2). We identified 11 LjbZIP proteins and 24 rLjbZIP proteins with conserved basic leucine zipper domains, subcellular localization, and electrophoretic mobility shift assay showed that the transcription factor LjbZIP8 is a nuclear-localized protein that specifically binds to the G-box element of the LjPAL2 5'-UTR. Additionally, a transactivation assay and LjbZIP8 overexpression in transgenic tobacco indicated that LjbZIP8 could function as a repressor of transcription. Finally, treatment with 5-azacytidine decreased the transcription level of LjPAL2 and CGAs content in FLJ leaves. These results raise the possibility that DNA methylation might influence the recruitment of LjbZIP8, regulating PAL2 expression level and CGAs content in L. japonica.

Comparison in antioxidant and antitumor activities of pine polyphenols and its seven biotransformation extracts by fungi

Microbial transformation can strengthen the antioxidant and antitumor activities of polyphenols. Polyphenols contents, antioxidant and antitumor activities of pine polyphenols and its biotransformation extracts by Aspergillus niger, Aspergillus oryzae, Aspergillus carbonarius, Aspergillus candidus, Trichodermas viride, Mucor wutungkiao and Rhizopus sp were studied. Significant differences were noted in antioxidant and antitumor activities. The highest antioxidant activities in Trolox equivalent antioxidant capacity (TEAC), DPPH radical scavenging activity, superoxide anion radical scavenging activity, hydroxyl radical scavenging activity, reducing power assay and antitumor activity against LoVo cells were biotransformation extract of Aspergillus carbonarius (BAC), biotransformation extract of Mucor wutungkiao (BMW), biotransformation extract of Aspergillus carbonarius (BAC), biotransformation extract of Aspergillus niger (BAN), biotransformation extract of Aspergillus oryzae (BAO) and BMW, respectively. Correlation analysis found that antioxidant and antitumor activities were associated with polyphenols contents and types of free radicals and tumors. A. carbonarius can make polyphenol oxidation, hydroxylation and methylation, and form new polyphenols. In conclusion, A. carbonarius, A. niger and M. wutungkiao are valuable microorganisms used for polyphenols biotransformation and enhance the antioxidant and antitumor activities of polyphenols.

Phytochemical Content, Health Benefits, and Toxicology of Common Edible Flowers: A Review (2000-2015)

Edible flowers contain numerous phytochemicals which contribute to their health benefits, and consumption of edible flowers has increased significantly in recent years. While many researchers have been conducted, no literature review of the health benefits of common edible flowers and their phytochemicals has been compiled. This review aimed to present the findings of research conducted from 2000 to 2015 on the species, traditional application, phytochemicals, health benefits, and the toxicology of common edible flowers. It was found in 15 species of common edible flowers that four flavonols, three flavones, four flavanols, three anthocyanins, three phenolic acids and their derivatives were common phytochemicals and they contributed to the health benefits such as anti-oxidant, anti-inflammatory, anti-cancer, anti-obesity, and neuroprotective effect. Toxicology studies have been conducted to evaluate the safety of common edible flowers and provide information on their dosages and usages.

A comparative study of the dynamic accumulation of polyphenol components and the changes in their antioxidant activities in diploid and tetraploid Lonicera japonica

Polyploidization is an effective method to achieve a higher yield of secondary metabolism active ingredients in medicinal plants. Polyphenols are the main active substances that contribute to the antioxidant activity of Lonicera japonica. For studying on the effect of chromosome doubling and harvest time on the dynamic accumulation of the main active substances and antioxidant capabilities of L. japonica, the polyphenol composition contents (7 phenolic acids and 3 flavonoids) and the antioxidant capacity in buds and flowers of diploid and tetraploid L. japonica at six different growth stages were determined by HPLC-DAD and three common antioxidant assays (FRAP, OH RSC and DPPH ARP), and the correlation between the dynamic accumulation of the polyphenol components and antioxidant capacity was also analyzed in current research. The results indicated that the content of the most determined phenolic acids and flavonoids and the antioxidant capacity in most of the growth stages from tetraploid plants were significantly higher than those in the diploid plants. Furthermore, the changes in the antioxidant activity presented a significant positive correlation with the variations in the chlorogenic acid, rutin, hyperoside, luteoloside in the two ploidy levels of L. japonica plants. The higher yields of chlorogenic acid (158.97, 164.00, 199.85 mg), luteoloside (5.44, 4.03, 6.31 mg), hyperoside (1.15, 1.06, 1.30 mg) and total flavonoids (9.87, 8.67, 11.10 mg) from 100 buds or flowers in tetraploid plants occurred during the S3-S5 stages, and these stages also exhibited higher antioxidant activities. Therefore, the stages of S3-S5 are recommended as the best time for harvesting high-yield, high-quality tetraploid Flos Lonicerae Japonicae.

An Efficient Method for the Preparative Isolation and Purification of Flavonoid Glycosides and Caffeoylquinic Acid Derivatives from Leaves of Lonicera japonica Thunb. Using High Speed Counter-Current Chromatography (HSCCC) and Prep-HPLC Guided by DPPH-HPLC Experiments

In this work, the n-butanol extract from leaves of Lonicera japonica Thunb. (L. japonica) was reacted with DPPH and subjected to a HPLC analysis for the guided screening antioxidants (DPPH-HPLC experiments). Then, nine antioxidants, including flavonoid glycosides and caffeoylquinic acid derivatives, were isolated and purified from leaves of L. japonica using high speed counter-current chromatography (HSCCC) and prep-HPLC. The n-butanol extract was firstly isolated by HSCCC using methyl tert-butyl ether/n-butanol/acetonitrile/water (0.5% acetic acid) (2:2:1:5, v/v), yielding five fractions F1, F2 (rhoifolin), F3 (luteoloside), F4 and F5 (collected from the column after the separation). The sub-fractions F1, F4 and F5 were successfully separated by prep-HPLC. Finally, nine compounds, including chlorogenic acid (1), lonicerin (2), rutin (3), rhoifolin (4), luteoloside (5), 3,4-O-dicaffeoylquinic acid (6), hyperoside (7), 3,5-O-dicaffeoylquinic acid (8), and 4,5-O-dicaffeoylquinic acid (9) were obtained, respectively, with the purities over 94% as determined by HPLC. The structures were identified by electrospray ionization mass spectrometry (ESI-MS), ¹H- and ¹³C-NMR. Antioxidant activities were tested, and the isolated compounds showed strong antioxidant activities.

An Efficient Method for the Preparative Isolation and Purification of Flavonoid Glycosides and Caffeoylquinic Acid Derivatives from Leaves of Lonicera japonica Thunb. Using High Speed Counter-Current Chromatography (HSCCC) and Prep-HPLC Guided by DPPH-HPLC Experiments

In this work, the n-butanol extract from leaves of Lonicera japonica Thunb. (L. japonica) was reacted with DPPH and subjected to a HPLC analysis for the guided screening antioxidants (DPPH-HPLC experiments). Then, nine antioxidants, including flavonoid glycosides and caffeoylquinic acid derivatives, were isolated and purified from leaves of L. japonica using high speed counter-current chromatography (HSCCC) and prep-HPLC. The n-butanol extract was firstly isolated by HSCCC using methyl tert-butyl ether/n-butanol/acetonitrile/water (0.5% acetic acid) (2:2:1:5, v/v), yielding five fractions F1, F2 (rhoifolin), F3 (luteoloside), F4 and F5 (collected from the column after the separation). The sub-fractions F1, F4 and F5 were successfully separated by prep-HPLC. Finally, nine compounds, including chlorogenic acid (1), lonicerin (2), rutin (3), rhoifolin (4), luteoloside (5), 3,4-Odicaffeoylquinic acid (6), hyperoside (7), 3,5-O-dicaffeoylquinic acid (8), and 4,5-O-dicaffeoylquinic acid (9) were obtained, respectively, with the purities over 94% as determined by HPLC. The structures were identified by electrospray ionization mass spectrometry (ESI-MS), 1H- and 13C-NMR. Antioxidant activities were tested, and the isolated compounds showed strong antioxidant activities.