Isatis Indigotica Research Articles

Discovery and molecular elucidation of the anti-influenza material basis of Banlangen granules based on biological activities and ultra-high performance liquid chromatography coupled with quadrupole-orbitrap mass spectrometry

Ethnopharmacological relevanceTraditional Chinese medicine (TCM) has a wide range of applications, including human healthcare-associated treatments and bioactive compound discovery. However, complex chemical systems present a significant challenge for chemical-material-based research and quality control. For instance, Banlangen (BLG) granules is a well-acknowledged TCM preparation widely used in clinical treatment of virus infection. However, its chemical basis of anti-influenza efficacy remains unclear.Aim of the study: In the present study, a systematic discovery strategy for identifying anti-influenza molecules based on biological activities and chemical analysis was established to contribute to the molecular elucidation of the anti-influenza material basis of Banlangen granules. Materials and methodsHemagglutinase inhibition (HAI) and neuraminidase inhibition (NAI) assays were used to compare the anti-influenza activities of different fractions of BLG granules against H1N1, H5N1 and H7N9 viruses. A comparative qualitative analysis of the chemical constituents in BLG granules and their fractions was performed using ultra-high-performance liquid chromatography coupled with quadrupole orbitrap mass spectrometry (UHPLC-Q-Exactive Orbitrap MS), in which a multiple mass spectrometry database platform and three compound identification strategies were used. The association between anti-influenza activities and chemical constituent characteristics was analyzed using multiple stoichiometries and data comparison strategies. ResultsThe results showed that the chromatography fractions F3 and F4 of the BLG granules had the highest anti-influenza activity. A total of 88 compounds were identified in the BLG granules, including 31 alkaloids, 16 organic acids, 10 nucleosides, 8 phenylpropanoids, 6 sulfur-containing compounds, 5 amino acids, 4 aromatic compounds, 3 aldehydes and ketones, 2 flavonoids, 1 alcohol, 1 carbohydrate, and 1 aliphatic compound. Out of these, 31 characteristic compounds were identified in fractions F3–F4 as candidate compounds with anti-influenza activity. Additionally, 6-methoxyquinoline and 4-guanidinobutanal were identified in BLG granules and its raw material (Isatidis Radix) for the first time. ConclusionIn this study, we proposed a systematic discovery strategy to thoroughly investigate the anti-influenza activity, chemical identification, and constituents-activity relationship of BLG granules. These data not only provided a deeper understanding of the molecular mechanism of the activity of BLG granules, but also presented a basis for the discovery of potential novel drug candidates and quality evaluation and control of BLG granules.

MORPHOLOGICAL AND CHEMICAL CHARACTERISTICS OF TWO SPECIES BELONG TO ALYSSEAE AND LEPIDIEAE TRIBES SPREAD IN NORTHERN IRAQ

This research was aimed to study three species which are prevalent in northern Iraq: Alyssium strigosum Banks and Sol., Clypeola jonthlaspi L, and Isatis tinctoria L. belonging to the Alysseae and Lepidieae tribes. The general characteristics of the roots, stems, leaves, fruits and seeds are studied and it turned out that and the two species A. strigosum and C. jonthlaspi are similar due to their belonging to the Alysseae tribe, and the species I. tinctoria differs since it belongs to the Lepidieae tribe. In addition, 6 secondary metabolites are diagnosed using the qualitative tests: alkalis, phenols, tannins, flavonoids, glycosides, and sapindales. The presence of terpenoids was not observed, and the alcohol extract is superior to the aqueous extract regarding the accuracy of the results. The phenols are detected using HPLC technology and four compounds are found: Rutin, Quercetin, Kaempferol and P-Coumarin. The importance of studying the chemical content comes from its use in subsequent studies and knowledge of its uses in the medical fields.

Nutritional Values and In Vitro Fermentation Characteristics of 29 Different Chinese Herbs

The present study evaluated the nutritional values and in vitro fermentation characteristics of 29 different Chinese herbs in order to develop effective feed additives for livestock nutrition. The Chinese herbs were analyzed for their chemical composition. The in vitro fermentation characteristics were evaluated using the gas production technique with swine cecal chyme inoculum. The results showed that the Allium tuberosum Rottl (Semen allii tuberosi, SAT) had the highest gross energy (GE), crude protein (CP), ether extract (EE), and total amino acid (TAA) contents, whereas Anemones raddeanae Rhizoma (Agstache rugosus, AR) had the highest crude fiber, neutral detergent fiber, and acid detergent fiber contents compared with the other Chinese herbs. The Rhus chinensis Mill (Chinese gall, CG), Scrophularia ningpoensis Hemsl (Radix scrophulariae, RS), Punica granatum L (Punica granatum L, PGL), Atractylodes macrocephala Koidz (White atractylodes rhizome, WAR), Sanguisorbae radix (Garden burnet, GB), Anemarrhena asphodeloides Bunge (Rhizoma anemarrhenaw, RA), and Rhei radix Et Rhizoma (Rheum officinale, RO) had a higher non-fiber carbohydrate content than the other Chinese herbs. The in vitro fermentation kinetic analysis showed that the RS, WAR, and RA had a higher gas production, a theoretical gas production, and a fractional rate of gas production than the other groups. Furthermore, the RA, WAR, RS, and Crataegi fructus (Crataegus pinnatifida Bun, CPB) had a higher total short-chain fatty acids (SCFAs) concentration, and CPB had the highest acetate concentration, whereas the WAR and RS had higher propionate and butyrate concentrations than the other groups. Moreover, the Isatis indigotica Fort (Folium isatidis, FI) and SAT had higher ammonia-N concentration than the other groups. In summary, among the 29 different Chinese herbs, the SAT had the highest nutritional value, which is reflected in the highest contents of GE, CP, EE, and TAA, whereas the RA, WAR, and RS showed better intestinal fermentation profiles, which is reflected in the higher fermentation degree and suitable SCFAs fermentation pattern. These findings provide a theoretical basis for using Chinese herbs as feed additives or microbial carbon sources in the intestines of animals.

Dihydroxyquingdainone Induces Apoptosis in Leukaemia and Lymphoma Cells via the Mitochondrial Pathway in a Bcl-2- and Caspase-3-Dependent Manner and Overcomes Resistance to Cytostatic Drugs In Vitro.

Isatis tinctoria and its indigo dyes have already provided highly active anti-leukaemic lead compounds, with the focus mainly being on indirubin, whereas indigo itself is inactive. There are many more indigoids to find in this plant extract, for example, quingdainone, an indigoid derived from tryptanthrin. We present here a new synthesis of hitherto neglected substituted quingdainones, which is very necessary due to their poor solubility behaviour, and a structure-dependent anti-leukaemic activity study of a number of compounds. Substituted α-phenylaminoacrylic acid was synthesised by hydrogen sulfide extrusion from an analogue mercaptoacetic acid, available from the condensation of rhodanin and a substituted tryptanthrin. It is shown that just improving water solubility does not increase anti-leukaemic activity, since a quingdainone carboxylic acid is inactive compared to dihydroxyquingdainone. The most effective compound, dihydroxyquingdainone with an AC50 of 7.5 µmole, is further characterised, revealing its ability to overcome multidrug resistance in leukaemia cells (Nalm-6/BeKa) with p-glycoprotein expression.

Enzymatic characterization of lignan glucosyltransferase of Isatis indigotica

The lignan glycosyltransferase UGT236(belonging to the UGT71 B family) from Isatis indigotica can catalyze the production of phloridzin from phloretin in vitro. UGT236 shares high identity with P2'GT from apple. In this study, the recombinant plasmid pET28 a-MBP-UGT236 was transferred into Escherichia coli Rosetta(DE3) cells and induced by isopropyl-β-D-thiogalactoside(IPTG). The purified UGT236 protein was used for enzymatic characterization with phloretin as substrate. The results showed that UGT236 had the optimal reaction temperature of 40 ℃ and the optimal pH 8(Na_2HPO_4-NaH_2PO_4 system). The UGT236 activity was inhibited by Ni~(2+) and Al~(3+), enhanced by Fe~(2+), Co~(2+), and Mn~(2+), and did not affected by Mg~(2+), Ca~(2+), Li~+, Na~+, or K~+. The K_m, K_(cat), and K_(cat)/K_m of phloretin were 61.03 μmol·L~(-1), 0.01 s~(-1), and 157.11 mol~(-1)·s~(-1)·L, and those of UDPG were 183.6 μmol·L~(-1), 0.01 s~(-1), and 51.91 mol~(-1)·s~(-1)·L, respectively. The possible active sites were predicted by homologous modeling and molecular docking. By mutagenisis and catalytic activity detection, three key active sites, Glu391, His15, and Thr141, were identified, while Phe146 was related to product diversity. In summary, we found that the lignan glycosyltransferase UGT236 from I.indigotica could catalyze the reaction of phloretin into phloridzin. Several key amino acid residues were identified by structure prediction, molecular docking, and site-mutagenesis, which provided a basis for studying the specificity and diversity of phloretin glycoside products. This study can provide a reference for artificially producing glycosyltransferase elements with high efficiency and specific catalysis.

A Novel Molecularly Imprinted Electrochemical Sensor Based on PANI@GO for Highly Sensitive and Selective Analysis of Trace Epigoitrin

Identification and quantification of epigoitrin (EP) in some herbs and traditional Chinese medicine (TCM) preparations are critical to pharmacokinetic study and pharmaceutical quality control due to its distinct antiviral activity. So, developing highly sensitive and selective method for detection of EP is essential for clinical treatment and drug development. In this study, a novel molecularly imprinted electrochemical sensor for detection of EP was firstly constructed. With acrylamide imprinting systems, surface imprinting on the polyaniline functionalized graphene oxide was employed to prepare molecularly imprinted polymer by electro-polymerization, which follow-up constructed afford specific binding cavities, endowing the exclusive recognition ability. Furthermore, the polyacrylamide chain is anchored to the polyaniline chain by covalent bonds, which is beneficial for raising electrochemistry signal. Under the optimized condition, the sensor demonstrates a linear wide range of 4.6 × 10−7 mol l−1 ∼ 4.6 × 10−5 mol l−1 with a correlation coefficient of 0.9953 and a low LOD of 8.21 × 10−8 mol l−1 (S/N = 3). Additionally, the sensor showed good stability, repeatability (RSD 1.52%) and selectivity. The method was applied to analyze EP in the extraction from Isatidis Radix with a recovery higher than 97.8% and RSD less than 1.81%. This work provided a novel strategy for on-site, real-time and rapid detection of indicator components from TCM.

Enhanced Oral Bioavailability of MT-102, a New Anti-inflammatory Agent, via a Ternary Solid Dispersion Formulation.

This study aimed to develop a solid dispersion (SD) of MT-102, a new anti-inflammatory agent, to improve its oral bioavailability. The ternary SD formulations of MT-102 (a poorly soluble extract of Isatis indigotica and Juglans mandshurica) were prepared using a solvent evaporation method with various drug/excipient ratios. Following that, the effectiveness of various SDs as an oral formulation of MT-102 was investigated using indirubin as a marker component. By forming SDs with hydrophilic polymers, the aqueous solubility of indirubin was significantly increased. SD-F4, containing drug, poloxamer 407 (P407), and povidone K30 (PVP K30) at a 1:2:2 weight ratio, exhibited the optimal dissolution profiles in the acidic to neutral pH range. Compared to pure MT-102 and a physical mixture, SD-F4 increased indirubin’s dissolution from MT-102 by approximately 9.86-fold and 2.21-fold, respectively. Additionally, SD-F4 caused the sticky extract to solidify, resulting in improved flowability and handling. As a result, compared to pure MT-102, the oral administration of SD-F4 significantly improved the systemic exposure of MT-102 in rats. Overall, the ternary SD formulation of MT-102 with a blended mixture of P407 and PVP K30 appeared to be effective at improving the dissolution and oral absorption of MT-102.

Hydroalcoholic Leaf Extract of Isatis tinctoria L. via Antioxidative and Anti-Inflammatory Effects Reduces Stress-Induced Behavioral and Cellular Disorders in Mice.

Stress that can occur at different levels of a person's life can cause and exacerbate various diseases. Oxidative stress and inflammation underlie this process at the cellular level. There is an urgent need to identify new and more effective therapeutic targets for the treatment of stress-induced behavioral disorders and specific drugs that affect these targets. Isatis tinctoria L. is a herbaceous species in the Brassicaceae family. Due to its potential antioxidant, nitric oxide- (NO-) inhibiting, anti-inflammatory, and neuroprotective properties, I. tinctoria could be used to treat depression, anxiety, and stress resistance. Hence, the present study is aimed at delineating whether administration of I. tinctoria leaf extract may improve stress-induced disorders in mice. A set of four behavioral tests was selected that together are suitable for phenotyping acute restraint stress-associated behaviors in mice, namely locomotor activity, social integration, dark/light box, and splash tests. The plasma and brains were collected. A brain-derived neurotrophic factor, tumor necrosis factor-alpha, C-reactive protein, corticosterone, NO, reactive oxygen species levels, superoxide dismutase and catalase activity, and ferric-reducing antioxidant power were measured. In mice stressed by immobilization, decreased locomotor activity, anxiety-like behavior, and contact with other individuals were observed, as well as increased oxidative stress and increased levels of nitric oxide in the brain and plasma C-reactive protein. A single administration of I. tinctoria leaf extract was able to reverse the behavioral response to restraint by a mechanism partially dependent on the modulation of oxidative stress, neuroinflammation, and NO reduction. In conclusion, Isatis tinctoria hydroalcoholic leaf extract can reduce stress-induced behavioral disturbances by regulating neurooxidative, neuronitrosative, and neuroimmune pathways. Therefore, it could be recommended for further research on clinical efficacy in depression and anxiety disorder treatment.

Desorption Electrospray Ionization Mass Spectrometry Imaging Illustrates the Quality Characters of Isatidis Radix

For a long history, herbal medicines have made significant contributions to human health all around the world. However, the exploration of an effective approach to illustrate their inner quality remains a challenge. So, it is imperative to develop new methods and technologies to characterize and identify quality markers of herbal medicines. Taking Isatidis Radix, the dried root of Isatis indigotica as an example, desorption electrospray ionization (DESI), in combination with quadrupole-time-of-flight mass spectrometry (Q-TOF/MS), was applied in this work for the first time to reveal the comprehensive spatial distribution of metabolites and, further, to illustrate quality characters of this herbal medicine. After simple pretreatment, 102 metabolites including alkaloids, sulfur-containing compounds, phenylpropanoids, nucleosides, amino acids, organic acids, flavonoids, phenols, terpenes, saccharides, peptides, and sphingolipids were characterized, some of which were successfully localized and visualized in the transverse section of the root. Based on the ion images, samples with different quality characters were distinguished unambiguously by the pattern recognition method of orthogonal partial least squares discrimination analysis (OPLS-DA). Simultaneously, 11 major influencing components exerting higher ion intensities in superior samples were identified as the potential quality markers of Isatidis Radix. Desorption electrospray ionization (DESI) mass spectrometry imaging (MSI), together with chemometric analysis could not only improve the understanding of the plant biology of herbal medicines but also be beneficial in the identification of quality markers, so as to carry out better quality control of herbal medicines.

Functional Characterization of UDP-Glycosyltransferases Involved in Anti-viral Lignan Glycosides Biosynthesis in Isatis indigotica.

Isatis indigotica is a popular herbal medicine with its noticeable antiviral properties, which are primarily due to its lignan glycosides such as lariciresinol-4-O-β-D-glucoside and lariciresinol-4,4′-bis-O-β-D-glucosides (also called clemastanin B). UDP-glucose-dependent glycosyltransferases are the key enzymes involved in the biosynthesis of these antiviral metabolites. In this study, we systematically characterized the UGT72 family gene IiUGT1 and two UGT71B family genes, IiUGT4 and IiUGT71B5a, with similar enzymatic functions. Kinetic analysis showed that IiUGT4 was more efficient than IiUGT1 or IiUGT71B5a for the glycosylation of lariciresinol. Further knock-down and overexpression of these IiUGTs in I. indigotica’s hairy roots indicates that they play different roles in planta: IiUGT71B5a primarily participates in the biosynthesis of coniferin not pinoresinol diglucoside, and IiUGT1 primarily participates in the biosynthesis of pinoresinol diglucoside, while IiUGT4 is responsible for the glycosylation of lariciresinol and plays a dominant role in the biosynthesis of lariciresinol glycosides in I. indigotica. Analysis of the molecular docking and site-mutagenesis of IiUGT4 have found that key residues for its catalytic activity are H373, W376, E397, and that F151 could be associated with substrate preference. This study elucidates the biosynthetic route of anti-viral lignan glycosides in I. indigotica, and provides the foundation for the production of anti-viral lignan glycosides via synthetic biology under the heterologous model.

Lignans and a neolignan from an aqueous extract of Isatis indigotica roots

Four new lignans (1−4) and one new neolignan (5), along with two known lignan derivatives (6 and 7), were isolated from an aqueous extract of the Isatis indigotica root (ban lan gen). Their structures were determined by spectroscopic data analysis, chemical method, and theoretical calculation, for which 1 was proved by single-crystal X-ray diffraction. Compound 2 exhibited antiviral activity against influenza virus A/Hanfang/359/95 (H3N2) with an IC50 value of 11.1 µM and a selective index (SI) > 9, while 1 and 5 are the first examples of sulfonated lignan and neolignan from nature.

Adenosine and L-proline can possibly hinder Chinese Sacbrood virus infection in honey bees via immune modulation

Sacbrood virus (SBV) infects larvae of honey bees, resulting in infected larvae becoming fluid-filled sacs. Our previous studies showed that the extract of herbal medicine, Radix Isatidis, could inhibit Chinese SBV (CSBV) infection in Asian honey bees (Apis cerana). Here, two compounds, adenosine and L-proline, which were previously reported to be associated with immune modulation, were identified in R. Isatidis extract and then selected for an evaluation of their antiviral effect on CSBV infection in A. cerana. Our results revealed that both adenosine and L-proline could significantly mitigate the impact of CSBV on the growth and development of infected larvae and modulate hosts' immune responses by downregulating the expression of immune genes in infected larvae. The results gained from this study suggest that adenosine and L-proline could possibly interfere CSBV infection via immune modulation to avoid exacerbations and nonspecific damage to infected larvae's own tissues.

Inhibitory effect of Isatis tinctoria L. water extract on DNCB-induced atopic dermatitis in BALB/c mice and HaCaT cells.

BackgroundIsatis tinctoria L (PLG) is a medicinal herb from the roots of Isatis indigotica Fort (Family Cruciferae). Previous studies have shown that PLG has anti-inflammatory and therapeutic effects against conditions such as acute and chronic hepatitis, various respiratory inflammations, and cancer. The purpose of this study was to define the pharmacological effects of PLG on inflammatory reactions and skin hyperkeratosis, which are the main symptoms of atopic dermatitis (AD), in vivo and in vitro.MethodsFor the AD in vivo experiment, 2,4-dinitrochlorobenzene (DNCB) induction and oral administration of PLG were performed on male BALB/c mice for four weeks. For in vitro experiments, keratinocytes were activated using TNF-α/IFN-γ in cultured human keratinocyte (HaCaT) cells. PLG inhibited inflammatory chemokine production and blocked the nuclear translocation of NF-κB p65 in activated keratinocytes.ResultsAs a result of oral administration of PLG, dermis and epidermis thickening, as well as eosinophil and mast cell infiltration, were attenuated in AD skin lesions. In addition, the levels of immunoglobulin E (IgE), pro-inflammatory cytokines, and the MAPK/NF-κB signaling pathway were decreased in serum and dorsal skin tissues. Furthermore, PLG inhibited inflammatory chemokine production and blocked the nuclear translocation of NF-κB p65 in activated keratinocytes. In addition, epigoitrin and adenosine, the standard compounds of PLG, were identified as candidate AD compounds.ConclusionsThese results indicate that PLG is a potent therapeutic agent for attenuating symptoms of AD.Supplementary InformationThe online version contains supplementary material available at 10.1186/s13020-022-00624-5.

Polysaccharide extract from Isatidis Radix inhibits multiple inflammasomes activation and alleviate gouty arthritis.

The polysaccharide extract from Isatidis Radix exhibits potent antiinflammatory and antiviral activities, but the mechanism of Isatidis Radix polysaccharide (IRP) remains obscure. Herein, we reported that IRP blocked the activation of nod-like receptor pyrin domain-containing 3 (NLRP3) inflammasome, leading to the inhibiting of caspase-1 cleavage and IL-1β secretion. Mechanistically, IRP did not inhibit NLRP3 inflammasome through suppressing mitochondrial reactive oxygen species (mtROS) production. However, IRP can significantly suppress the oligomerization of apoptosis-associated speck-like protein (ASC) and subsequently block the formation of inflammasome. Next, we evaluate the role of IRP in monosodium urate (MSU)-induced gout in vivo which is a NLRP3-associated disease. We also observed that oral administration of IRP can reduce the increased ankle thickness and the secretion of IL-1β, IL-18, IL-6, TNF-α and MPO of the mouse ankle joints caused by MSU crystals. Furthermore, flow cytometry analysis highlighted a significant modulation of T helper 17 cells (Th17)/regulatory T cells (Treg) following IRP treatment in MSU induced gout. Overall, our findings suggest that IRP has comprehensive and potent antiinflammatory effects and provide a reasonable therapeutic strategy in preventing inflammasome-associated diseases, such as inflammatory gouty arthritis.

Effects of Regulated Deficit Irrigation on Yield and Quality of Isatis indigotica in a Cold and Arid Environment

Although regulated deficit irrigation may improve crop yields, little research has been conducted on the effects of water deficits on Isatis indigotica, a popular herbal medicine. Field experiments were conducted in 2016 and 2017 to study the effects of regulated deficit irrigation on the net photosynthetic rate, yield, water use efficiency (WUE), and quality of I. indigotica in northwest China. Plants at the vegetative and fleshy root growth stages were subjected to mild, moderate, and severe water deficits, and their photosynthetic physiological indexes, yield, and WUE were measured. Moderate and severe deficits, but not a mild deficit, significantly decreased the net photosynthetic rate and dry matter accumulation. The yield and WUE under mild deficit were markedly higher, reaching 8239.56 kg·ha−2 and 8390.80 kg·ha−2, respectively, in the vegetative stage and 24.11 kg·ha−2·mm−1 and 23.62 kg·ha−2·mm−1, respectively, in the fleshy root growth stage, while severe deficits significantly reduced yield and WUE. Mild and moderate deficits increased the content of (R,S)-goitrin, indirubin, and indigo, improving root quality, but severe deficits decreased these compounds. Therefore, a mild water deficit in the vegetative and fleshy root growth stages is optimal and can reduce water consumption and improve I. indigotica quality and WUE without reducing yield.

The pharmaceutical applications of total flavonoids extract from Isatis tinctoria L. leaves

Isatis tinctoria L. leaves (Folium isatidis), as dried leave of the isatis indigotica in the cruciferous family, has a variety of pharmacological effects, including regulation of immune function, anti-inflammatory, bacteriostasis, antipyretic effect. In this study, total flavonoids extract from Folium isatidis was systematically studied about extractive process, main components, antibacterial, antioxidant and anti-inflammatory activities. The total flavonoids extract yield was (7.65±0.07)% under the optimal extraction parameters of ethanol concentration 54.37%, ratio of solvent volume to material weight 40:1 ml/g, and ultrasonic extraction time 20 min. Nineteen chemical components were inferred and identified by UPLC-QTOF-MS method. Although the extract showed mild antibacterial and antioxidant effects with MIC values 31.25, 62.5, 125 and 125 mg/ml against Streptococcus, Salmonella, Staphylococcus aureus and Escherichia coli, and IC50 DPPH 12.64 µg/ml, IC50 ABTS 16.72 µg/ml and FRAP value at 0.11 mmol Fe2+/100 µg/ml compared with the positive control butylated hydroxytoluene with IC50 DPPH 8.13 µg/ml, IC50 ABTS 2.22 µg/ml and FRAP value at 0.16 mmol Fe2+/100 µg/ml. It exhibited better anti-inflammatory effects in LPS induced RAW 264.7 cell (50, 100 and 200 µg/ml of TFE) and ALI mice (100, 250, or 500 mg/kg•b•w of TFE), which was demonstrated by reducing cell phagocytic activity, decreasing the content of pro-inflammatory cytokine and inflammatory mediator, and improving lung tissue injury. Furthermore, the mechanism of anti-inflammatory action was further revealed to be related to the regulation of TLR4-TRIF-NF-κB signaling pathway. These studies revealed that total flavonoids extract could be used as a natural and green candidate for anti-inflammatory drugs and enrich the variety of clinical anti-inflammatory drugs.

Research progress in DIR gene of lignan biosynthesis in medicinal plants

The active components, mainly derived from secondary metabolites of medicinal plants, are the material basis for the efficacy of medicinal plants. Lignans, the secondary metabolites in plants with high bioactivity, are widely distributed in a variety of plant species, and their antiviral, antitumor, antibacterial, and antioxidant activities have been proved in clinical practice. Generally, lignans are diverse in structures with many chiral centers, and most of them are optically active. The biosynthesis of lignans depends on the oxidative coupling reaction through site selection and stereo selection, which impedes synthesized lignans to form racemates, but makes them in a three-dimensional configuration. Dirigent protein(DIR) plays an important role in guiding location selection and stereo selection of lignans in biosynthesis. In vitro studies on lignan biosynthesis have shown that racemic end products are obtained in the absence of DIR proteins, while the products in a three-dimensional configuration can be yielded in the presence of DIR proteins, indicating that DIR proteins play an asymmetric role in the biosynthesis of plant secondary metabolites. The present study reviewed the biolo-gical significance of DIR protein, the cloning of DIR gene, gene structure, catalytic mechanism, and the research progress in Isatis indigotica, Eucommia ulmoides, Forsythia suspensa, Salvia miltiorrhiza, Panax pseudoginseng var. notoginseng, and Schisandra chinensis, which provides a reference for the follow-up research of DIR gene.

Protective effects of Radix Isatidis polysaccharide ameliorates obesity via promotion AMPK pathway in high-fat-diet-induced obese rats and 3T3-L1 adipocyte cells.

The purpose of this paper is to ascertain the effect and mechanism of Radix Isatidis polysaccharide (RIP) on obesity. High fat diet (HFD)-induced obese rats and the MDI-induced 3T3-L1 adipocyte cells were established to evaluate the ameliorated obesity effect and mechanism from RIP. Experiments in vivo show that oral administration of RIP has significant preventive effects on HFD-induced obesity and metabolic disorders in rats. With treatment of RIP (20, 40 and 80 mg/kg BW), the body weight, fat accumulation, adipocyte cell size, serum lipid levels and antioxidant enzyme activity were progressively improved. On the other hand, the treatment of 3T3-L1 cells with RIP (25, 50 and 100 mg/L) led to a decrease in lipid accumulation and glucose consumption. In addition, during adipogenesis in 3T3-L1 cells, RIP remarkably down-regulated mRNA levels of peroxisome proliferator-activated receptor-γ (PPARγ), CCAAT/enhancer binding protein-α (C/EBPα), sterol regulatory element-binding protein-1c (SREBP-1c), fatty acid synthase (FAS), acetyl-CoA carboxylase and glycerol-3-phosphate dehydrogenase. Furthermore, after RIP treatment, the protein expression of PPARγ, C/EBPα, FAS, HMG-CoA reductase and acetyl-CoA synthetase-1 (AceCS1) were significantly decreased and the expression of p-AMPK was increased. These results highlight the potential of RIP for obesity interventions and suggest that RIP inhibited adipocyte differentiation and lipid synthesis by activating adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK) signalling pathway and down-regulating the expression of major adipogenic transcription factors, PPARγ, C/EBPα, etc.

Isatis tinctoria L. Leaf Extract Inhibits Replicative Senescence in Dermal Fibroblasts by Regulating mTOR-NF-κB-SASP Signaling.

Senescent fibroblasts progressively deteriorate the functional properties of skin tissue. Senescent cells secrete senescence-associated secretory phenotype (SASP) factor, which causes the aging of surrounding non-senescent cells and accelerates aging in the individuals. Recent findings suggested the senomorphic targeting of the SASP regulation as a new generation of effective therapeutics. We investigated whether Isatis tinctoria L. leaf extract (ITE) inhibited senescence biomarkers p53, p21CDKN1A, and p16INK4A gene expression, and SASP secretions by inhibiting cellular senescence in the replicative senescent human dermal fibroblast (RS-HDF). ITE has been demonstrated to inhibit the secretion of SASP factors in several senomorphic types by regulating the MAPK/NF-κB pathway via its inhibitory effect on mTOR. ITE suppressed the inflammatory response by inhibiting mTOR, MAPK, and IκBα phosphorylation, and blocking the nuclear translocation of NF-κB. In addition, we observed that autophagy pathway was related to inhibitory effect of ITE on cellular senescence. From these results, we concluded that ITE can prevent and restore senescence by blocking the activation and secretion of senescence-related factors generated from RS-HDFs through mTOR-NF-κB regulation.

The complete chloroplast genome of Isatis cappadocica Desv. (Brassicaceae)

Isatis cappadocica Desv. is a vigorous perennial rosette plant and it can grow in highly arsenic-contaminated areas. In this study, the complete chloroplast genome of I. cappadocica was assembled and annotated. The total length of this genome is 153,800 bp and the GC content is 36.48%. It has a typical four-part structure: a pair of inverted repeat sequences (26,270 bp each), a small single-copy region (17,715 bp), and a large single-copy region (83,545 bp). The annotation results show that it contains 132 genes. The phylogenetic analysis of I. cappadocica and other 18 representative plants indicates that I. cappadocica is closely related to Isatis tinctoria.