Isatis Indigotica Research Articles

Polygonum tinctorium leaves suppress sodium dextran sulfate-induced colitis through interleukin-10-related pathway

Indigo naturalis, a herbal medicine purified from indigo-containing plants, such as Strobilanthes cusia, Isatis tinctoria, and Polygonum tinctorium, has been reported to be useful in the treatment of ulcerative colitis by activating the aryl hydrocarbon receptor. However, the aryl hydrocarbon receptor pathway causes crucial side effects, such as pulmonary arterial hypertension. Although P. tinctorium is one of the plant derivatives of indigo naturalis, it is not identical to it. To date, the pure leaves of P. tinctorium have not been reported to ameliorate ulcerative colitis. Therefore, we investigated the effect of pure P. tinctorium leaves, which are consumed in some regions, on experimental colitis induced in mice using sodium dextran sulfate. We found that P. tinctorium leaves ameliorated weight loss (P < 0.01) and pathological inflammatory changes in the colon (P < 0.05), enhanced mRNA expression of interleukin-10 (P < 0.05), and decreased expression of tumor necrosis factor-in colonic tissues (P < 0.05), as determined using quantitative real-time reverse transcription polymerase chain reaction. The intraperitoneal administration of an aryl hydrocarbon receptor antagonist did not antagonize the inhibition of mucosal destruction, whereas an anti-interleukin-10 receptor antibody did. These results suggest that P. tinctorium ameliorate sodium dextran sulfate-induced intestinal inflammation via interleukin-10-related pathway, independent of the aryl hydrocarbon receptor pathway. P. tinctorium leaves have the potential to be a new, safe treatment for ulcerative colitis.

Functional identification of the different regions in B-class floral homeotic MADS-box proteins IiAP3 and IiPI from Isatis indigotica.

APETALA3 (AP3) and PISTILLATA (PI) are B-class MADS-box floral homeotic genes of Arabidopsis and are involved in specifying the identity of petals and stamens. In the present work, IiAP3 and IiPI, the respective orthologous genes of AP3 and PI, were cloned from Isatis indigotica. By expressing in ap3-6 and pi-1 homozygous mutant and in wild-type Arabidopsis under the control of AP3 promoter or CaMV 35S promoter, we demonstrated that IiAP3 and IiPI were functionally equivalent to AP3 and PI of Arabidopsis. Referring to previous reports and the research results in the present work, expression patterns of AP3 and PI homologs are not the same in different angiosperms possessing diverse floral structures. It suggests that the alterations in expression may contribute to the changing morphology of flowers. To further determine the relationship between IiAP3 and IiPI, the coding sequences of the different structural regions in these two proteins were swapped with each other, and the data collected from transgenic Arabidopsis plants of the chimeric constructs suggested that MADS domain was irreplaceable for the function of IiAP3, K domain of IiAP3 was involved in specifying the identity of stamens, K domain of IiPI was mainly related to the formation of petals, and C-terminal region of IiPI was involved in characterization of stamens. In addition, a complete KC region of these two proteins was more effective in phenotypic complementation of the mutants.

The Importance of Flavonoids and Phytochemicals of Medicinal Plants with Antiviral Activities

Abstract: In this mini-review article, we have mentioned the key roles of some of the most important herbal plants medicine containing flavonoids and phytochemicals with antiviral activities. All relevant information was searched by using the terms, influenza, phytochemicals, SARS, SARSCov- 2, flavonoids, and traditional medicinal plants uses, from reliable databases, such as PubMed, Science Direct, and Google Scholar. The most important medicinal herbs which contain flavonoids with antiviral activities are Limonium densiflorum, Oroxylum indicum, Tribulus terrestris L., Paulownia tomentosa Steud., Allophylus africanus, Houttuynia cordata, Moslea Herba, Mosla scabra, Scutellaria baicalensis, Berries, Genus Psoralea, Sophora tonkinensis, Trollius chinensis, Tilia cordata, Hippophae rhamnoides L. (Seabuckthorn), Paulownia tomentosa steud, and C. swietenia. Phytochemicals are chemicals of plant origin produced by plants through primary or secondary metabolism. The most important medicinal plants, which contain phytochemicals with antiviral activities are Blue honeysuckle (Lonicera caerulea L.), Forsythia suspense, Ligustrum lucidum, Radix Paeoniae Alba (Bai Shao), Banlangen (Radix Isatidis), Lysiphyllum strychnifolium, Phellinus baumii, Mesona chinensis, Sanguinaria Canadensis, Dodonaea viscosa, Isatis indigotica, Pelargonium sidoides, Entada Africana Guill., Pomegranate (Punica granatum), Goldenseal (Hydrastis canadensis), Lychee fruit extract, Lycoris radiate, Cistus incanus, Chaenomeles sinensis Koehne (Chinese quince), Geranium sanguineum L., and Tea polyphenols. Natural products from traditional herbal medicines, especially traditional Chinese and Persian medicines, have been found to exert antiviral impacts against influenza and human coronaviruses. The natural plant-derived compounds that have been used for treating various diseases are flavonoids and phytochemicals.

Gandan Oral Liquid Improves Exudative Pneumonia by Upregulating Bacteria Clearance via Regulating AQP5 and MUC5AC in Rats

Gandan oral liquid (GOL) is a mixture of crude extracts from licorice and Radix isatidis. Clinically, it has been widely used in the treatment of exudative pneumonia (EP) in animals. But the molecular mechanism of these effects is unclear. Therefore, antibacterial activity and therapeutic effect were tested in vitro and in vivo. Exudative pneumonia was established with the intraperitoneal injection of LPS, followed by continuous intranasal inoculation of Klebsiella pneumoniae (KP). After that, Gandan oral liquid, acetylcysteine, and levofloxacin were given through the intragastric route for five days, and clinical symptoms were observed and counted. The bacterial content of alveolar lavage fluid was determined, hematology analysis was performed, and lung histology examination was performed. Western blotting, immunohistochemistry, and immunofluorescence were used to detect the expression levels of AQP3, AQP5, and MUC5AC in lung tissues. ELISA kit was used to detect serum and BALF cytokines levels. The results showed that GOL (242 mg/mL) had no antibacterial activity on Klebsiella pneumonia (KP), and the effect was significantly worse than levofloxacin. However, the therapeutic test in vivo of the rat model of bacterial EP showed different results. After treatment, GOL administration ameliorated EP and increased the expression of mucoprotein -5AC (MUC5AC), and GOL promoted water secretion of the respiratory tract by increasing the expression of aquaporin-5 (AQP5) and decreasing the levels of proinflammatory cytokines (TNF-α, IL-6, and IL-1β). Conclusion. GOL accelerates the water secretion of respiratory tract, inhibits the inflammatory response, induces removal of bacteria of respiratory tract via the AQPs/MUC pathway, and ultimately ameliorates EP.

Sulfonated alkaloids from an aqueous extract of Isatis indigotica roots

Eleven new sulfonated alkaloids (1 − 11) having diverse structures 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, of which (−)-4 was proved by single crystal X-ray diffraction.

In Vitro Anthelmintic Activity of Isatis tinctoria Extracts against Ewes' Gastrointestinal Nematodes (GINs), a Possible Application for Animal Welfare.

Sheep gastrointestinal nematode (GIN) infestation represents a limiting factor for sheep farming and milk production in Italy. The development of anthelmintic resistance to conventionally used drugs suggests the path towards the use of natural remedies as a possible alternative. The purpose of this study is to evaluate the in vitro anthelmintic efficacy of the hydroalcoholic extracts of basal leaves (It-BL), cauline leaves (It-CL) and flowers (It-F) of Isatis tinctoria (Brassicaceae), a spontaneous Sicilian species renowned as an important source of bioactive compounds. The dry extracts of the different parts of the plant were tested using the egg hatch test (EHT) in vitro to verify the efficacy against ovine GIN at different concentrations (1.00, 0.5, 0.25, 0.125 mg/mL). Thiabendazole and deionized water were used as positive and negative controls, respectively. The results obtained from EHT indicated that all the I. tinctoria extracts were highly effective (p < 0.0001) in inhibiting egg hatching within 48 h of exposure. The in vitro inhibitory effect was never less than 84% in all doses tested, and it was only slightly lower than the standard drug thiabendazole (95.6%). The current study documents the anthelmintic activity of I. tinctoria against sheep’s GIN, suggesting its application as alternative natural method to limit the use of antiparasitic drugs.

Comparative study of water-soluble polysaccharides isolated from leaves and roots of Isatis indigotica Fort.

Water-soluble polysaccharides were isolated from the leaves and roots of Isatis indigotica Fort., and their structural features were studied and compared. One neutral polysaccharide fraction (WFIP-N) and three pectin fractions (WFIP-A-A, WFIP-A-B and WFIP-A-C) were obtained from the leaves, and one neutral polysaccharide fraction (WRIP-N) and two pectin fractions (WRIP-A-A and WRIP-A-B) were obtained from the roots. WFIP-A-B (Mw = 34.6 kDa) and WRIP-A-B (Mw = 29.9 kDa) were the major pectic polysaccharides. Monosaccharide composition, FT-IR, enzymatic hydrolysis, NMR and methylation analysis indicated that both WFIP-A-B and WRIP-A-B are composed of rhamnogalacturonan I (RG-I), rhamnogalacturonan II (RG-II) and homogalacturonan (HG) domains with mass ratios of 1.5:1.0:0.4 and 0.3:1.0:1.7, respectively. WFIP-A-B and WRIP-A-B were found to be rich in RG-I and HG domains, respectively, and mainly contained type II arabinogalactan (AG-II) and α-L-1,5-arabinan side chains, but those in WRIP-A-B were more numerous and longer. Our results provide structural features and differences between these polysaccharides which will help to elucidate their functional differences.

SEPALLATA--like genes of Isatis indigotica can affect the architecture of the inflorescences and the development of the floral organs.

BackgroundThe architecture of inflorescence and the development of floral organs can influence the yield of seeds and have a significant impact on plant propagation. E-class floral homeotic MADS-box genes exhibit important roles in regulation of floral transition and differentiation of floral organs. Woad (Isatis indigotica) possesses unique inflorescence, floral organs and fruit. However, very little research has been carried out to determine the function of MADS-box genes in this medicinal cruciferous plant species.ResultsSEPALLATA orthologs in I. indigotica were cloned by degenerate PCR. The sequence possessing the highest identity with SEP2 and SEP4 of Arabidopsis were named as IiSEP2 and IiSEP4, respectively. Constitutive expression of IiSEP2 in Columbia (Col-0) ecotype of Arabidopsis led to early flowering, and the number of the flowers and the lateral branches was reduced, indicating an alteration in architecture of the inflorescences. Moreover, the number of the floral organs was declined, the sepals were turned into carpelloid tissues bearing stigmatic papillae and ovules, and secondary flower could be produced in apetalous terminal flowers. In 35S::IiSEP4-GFP transgenic Arabidopsis plants in Landsberg erecta (Ler) genetic background, the number of the floral organs was decreased, sepals were converted into curly carpelloid structures, accompanied by generation of ovules. Simultaneously, the size of petals, stamens and siliques was diminished. In 35S::IiSEP4-GFP transgenic plants of apetalous ap1 cal double mutant in Ler genetic background, the cauliflower phenotype was attenuated significantly, and the petal formation could be rescued. Occasionally, chimeric organs composed of petaloid and sepaloid tissues, or petaloid and stamineous tissues, were produced in IiSEP4 transgenic plants of apl cal double mutant. It suggested that overexpression of IiSEP4 could restore the capacity in petal differentiation. Silencing of IiSEP4 by Virus-Induced Gene Silencing (VIGS) can delay the flowering time, and reduce the number and size of the floral organs in woad flowers.ConclusionAll the results showed that SEPALLATA-like genes could influence the architecture of the inflorescence and the determinacy of the floral meristems, and was also related to development of the floral organs.

Insights into glucosinolate accumulation and metabolic pathways in Isatis indigotica Fort.

BackgroundGlucosinolates (GSLs) play important roles in defending against exogenous damage and regulating physiological activities in plants. However, GSL accumulation patterns and molecular regulation mechanisms are largely unknown in Isatis indigotica Fort.ResultsTen GSLs were identified in I. indigotica, and the dominant GSLs were epiprogoitrin (EPI) and indole-3-methyl GSL (I3M), followed by progoitrin (PRO) and gluconapin (GNA). The total GSL content was highest (over 20 μmol/g) in reproductive organs, lowest (less than 1.0 μmol/g) in mature organs, and medium in fresh leaves (2.6 μmol/g) and stems (1.5 μmol/g). In the seed germination process, the total GSL content decreased from 27.2 μmol/g (of seeds) to 2.7 μmol/g (on the 120th day) and then increased to 4.0 μmol/g (180th day). However, the content of indole GSL increased rapidly in the first week after germination and fluctuated between 1.13 μmol/g (28th day) and 2.82 μmol/g (150th day). Under the different elicitor treatments, the total GSL content increased significantly, ranging from 2.9-fold (mechanical damage, 3 h) to 10.7-fold (MeJA, 6 h). Moreover, 132 genes were involved in GSL metabolic pathways. Among them, no homologs of AtCYP79F2 and AtMAM3 were identified, leading to a distinctive GSL profile in I. indigotica. Furthermore, most genes involved in the GSL metabolic pathway were derived from tandem duplication, followed by dispersed duplication and segmental duplication. Purifying selection was observed, although some genes underwent relaxed selection. In addition, three tandem-arrayed GSL-OH genes showed different expression patterns, suggesting possible subfunctionalization during evolution.ConclusionsTen different GSLs with their accumulation patterns and 132 genes involved in the GSL metabolic pathway were explored, which laid a foundation for the study of GSL metabolism and regulatory mechanisms in I. indigotica.

Prevention Activity of a New Heterocycle Compound from Isatis indigotica on Hypotension After Anesthesia and Complete Chloroplast Genome Sequence

During the operation, the use of anesthetics or analgesics and bleeding will cause hypotension on patients, thus seriously threatening the patient’s life and safety. Isatis indigotica is utilized as traditional drug, which is an important medicinal herb with various biological activities because of the presence of different secondary metabolites. The role of a new compound extracted from Isatis indigotica on hypotension after anesthesia was determined, and the internal principle was discussed simultaneously. At first, operation under anesthesia was carried out, the compound was administered for treatment, and the blood pressure level of the mice was measured. In addition, real time RT-PCR was conducted, and the expression level of α receptor expression on peripheral vascular endothelial cells was measured. Additionally, the neighbor-joining phylogenetic results manifested that I. indigotica and Raphanus sativus clustered with other related categories.

Ban-Lan-Gen Granule Alleviates Dextran Sulfate Sodium-Induced Chronic Relapsing Colitis in Mice via Regulating Gut Microbiota and Restoring Gut SCFA Derived-GLP-1 Production.

PurposeGLP-1 based therapy represents a new treatment option for inflammatory bowel disease. Ban-Lan-Gen (BLG) granule, a known anti-viral TCM formulation, exhibits potential anti-inflammatory activities in treating various kinds of inflammation. However, its anti-inflammatory effect on colitis and the underlying mechanisms remain unknown.MethodsDextran sulfate sodium (DSS)-induced chronic relapsing colitis in mice was established. The disease activity index, histological sign of damage, and levels of proinflammatory cytokines were performed to assess the protective effects of BLG. Serum GLP-1 level and colonic Gcg, GPR41 and GRP43 expression, the community compositions of gut microbiota, the levels of SCFAs in the feces and GLP-1 release from primary murine colon epithelial cells were performed to characterize the effects of BLG on gut microbiota and gut SCFA derived-GLP-1 production.ResultsBLG treatment significantly alleviated body weight loss, DAI, colon shortening, colon tissue damage, and pro-inflammatory cytokine levels of TNF-α, IL-1β and IL-6 in the colon tissues. Moreover, BLG treatment could observably restore colonic Gcg, GPR41 and GRP43 expression and serum GLP-1 level of colitic mice, as well as correct the alteration of gut microbiota in colitic mice by increasing the abundances of SCFA-producing bacteria, eg, Akkermansia and Prevotellaceae_UCG-001, and decreasing the abundances of bacteria, eg, Eubacterium_xylanophilum_group, Ruminococcaceae_UCG-014, Intestinimonas, and Oscillibacter. Furthermore, BLG treatment could markedly increase the levels of SCFAs in feces of colitic mice. In parallel, ex vivo assay also showed that and the extract of feces from BLG-treatment mice could greatly stimulate the secretion of GLP-1 from primary murine colon epithelial cells.ConclusionThese findings suggest that the anti-colitis effects of BLG are achieved at least partly by regulating gut microbiota and restoring gut SCFA derived-GLP-1 production, and BLG has the potential to be developed as a promising agent for the treatment of chronic relapsing colitis.

First Report of Southern Root-Knot Nematode, Meloidogyne incognita, Infecting Isatis indigotica Fortune in Anhui Province, China.

Isatis indigotica Fortune, widely cultivated in China, is an important Chinese herbal medicine, mainly used to treat cold and fever. In October 2020, galls (Fig. 1), as many as 65 per root, were observed on the roots of I. indigotica in Taihe, Anhui Province, China (117°21'19.5"N, 32°57'59.5"E), and samples were taken. The infected plants were weak, and the leaves are wilting. Second-stage juveniles (J2s) were dissected from the egg masses released by females. Excretory pores of females were located nearby median bulb (Fig. 2A). The dorsal arch of the perineal pattern (n = 10) of the female was elliptical, and the dorsal arch was relatively high with smooth to wavy lines (Fig. 2B). Morphometrics of females (n=10): body length (L) = 595.5 ± 24.0 (570.0-620.5) μm, body width (W)= 350.5 ± 30.0 (320.0-390.5) μm, stylet length = 13.6 ± 0.7 (12.1-15.4) μm (Fig. 2A), and the distance from dorsal esophageal gland orifice to base of stylet (DGO) = 3.5 ± 0.2 (2.8-4.0) μm (Fig. 2B). J2s (n = 20) had the following characteristics: L = 383.2 ± 12.5 (337-430) μm (Fig. 2C), a = 22.0 ± 1.1 (20.3-24.4) μm, c = 8.4 ± 0.5 (7.5-10.5) μm, stylet length = 12.4 ± 1.5 (10.1-14.6) μm, DGO = 2.9 ± 0.6 (2.0-3.6) μm (Fig. 2D), tail length = 39.5 ±3.4 (32.0-48.5) μm and hyaline tail terminus = 10.5 ± 0.5 (9.5-11.2) μm (Fig.1E). There were four lines on the lateral field of J2s (Fig. 2F). Females and J2s obtained from galls had uniform morphological and molecular characteristics were confirmed to be Meloidogyne incognita. Live J2s were detected in all soil samples with a mean of 120 ± 15 J2s/100 ml of soil. Five 4-week-old I. indigotica plantlets, grown in pots (500cm3) with sterilized soil were inoculated with 1000 J2s from egg masses per pot and5 non-inoculated pots were used as control. Plants were well maintained under 25 ± 3°C in the greenhouse. Three plants were gently removed from the pots 30 days after inoculation, and an average of 50 galls per root was observed on the roots, and the resulting nematode reproduction factors (RF = final egg density ÷ 1,000, initial egg density) of 3.2, suggested that I. indigotica is a good host for M. incognita (Mojtahedi, 1988). There were no significant differences in main measurements and morphological characteristics between the Taihe population of M. incognita and that represented in "CIH descriptions of plant-parasitic nematodes" (Orton Williams, 1973). DNA was extracted from 5 single J2s, and ITS and 18S rDNA gene was amplified using the primer pair 18S/26S and 18s1.2a/18sr2b (Bernard et al. 2010; Vrain et al. 1992). The sequence of 18S rDNA (MW875892) was submitted to GenBank. Comparisons showed a sequence identity of greater than 99.8% for Meloidogyne incognita (MF177719.1). The rDNA sequences of M. incognita, M. hapla, M. javanica and M. arenaria are so homologous that rDNA-based differentiation is difficult. The SCAR primers can successfully distinguish M. incognita, M. hapla, M. javanica and M. arenaria. Five species-specific primer sets (Finc/Rinc; MORF-F/MTHIS-R; Jmv-F/Jmv-R; Far/Rar and Fjav/Rjav, Stanton et al. 1997; Wishart et al. 2002; Zijlstra et al. 2000) were used to species-specifically distinguish within the genus. The results (＋, ＋, －, －, －) proved that the Taihe population belonging to M. incognita. To our knowledge, this is the first report of M. incognita parasitizing I. indigotica. This finding may be important to medicinal plant industry, since M. incognita is one of the most harmful nematode pests in the world and would cause severe damage to I. indigotica.

A 96-Well Plates-based UV Spectrophotometric Assay for Determination of Total Glucosinolates in Isatis indigotica Roots

Background: Glucosinolates (GLS) are important secondary metabolites in Cruciferae vegetables and herbs. Currently, the assays of total GLS determination are cumbersome (requiring acidic or enzymatic hydrolysis and addition of staining reagents), time-consuming, and indirect. High concentrations of inorganic salts are inevitably incorporated into the GLS products during separation. There is a need for a quantitative method for simple and rapid determination of total GLS after desalting process. Methods: A 96-well plates-based UV spectrophotometric method for determination of total GLS of Isatis indigotica roots was developed in the present study. The detection wavelength is set at 230 nm using quartz plates. This assay was validated using gluconapin and sinigrin as reference standards, and applied to determine the total GLS of I. indigotica roots prepared from five different desalting methods. Results: This assay is specific for total GLS prepared from I. indigotica roots, and it has acceptable accuracy (91.76–98.18% for quality control, and 95.59–102.52% for addition/recovery), precision (0.24–0.70% pooled RSD), reproducibility (0.31–1.84% RSD), and stability (0.24–1.45% RSD) over a 72-h period. Conclusion: The 96-well plates-based UV spectrophotometric assay is simple and accurate for high-throughput determination of total GLS.

The effects of methyl jasmonate on growth, gene expression and metabolite accumulation in Isatis indigotica Fort.

Methyl jasmonate (MeJA) plays important roles on growth, gene expression and metabolite accumulation in plants. In this study, the physiological and biochemical characteristics, transcriptome and metabolome profiles of Isatis indigotica Fort., responded to MeJA were explored. Under the treatment, the contents of dry matter, chlorophyll and carotenoids increased significantly, while the water content did not. And the contents of soluble protein, flavonoid and lignin were also raised significantly, but the soluble sugar decreased. Besides, the enzyme activities of phenylalanine ammonia lyase (PAL), lipoxygenase (LOX), polyphenol oxidase (PPO), peroxidase (POD), catalase (CAT) and superoxide dismutase (SOD) increased, showing certain resistance characteristics of this plant. Based on RNA-seq, 31,769 unigenes were functionally annotated, and 2725 differential expressed genes (DEGs) identified. Among them, 57 DEGs covered most of the catalytic steps in general biosynthesis pathways of jasmonic acid, glucosinolates and phenylpropanoid. Referring to the metabolomics analysis, 175 significant differential metabolites were detected by GC-MS, combined with LC-MS method. Moreover, 53 differential metabolites were identified by the multivariate statistical analysis, mainly enriched in 37 different metabolic pathways, with most differential metabolites found in phenylalanine metabolism pathway. The results provided the comprehensive analysis on growth, transcriptome and metabolite profiles responded to MeJA, and gave new insights into revealing and enriching the functions of MeJA, contributing to explore the key genes and their functions on growth and metabolite accumulation and regulation process in I. indigotica.

Effects of water saving and nitrogen reduction on the yield, quality, water and nitrogen use efficiency of Isatis indigotica in Hexi Oasis

Isatis indigotica planting is the backbone of the medicinal industry in Hexi Oasis, Gansu. In order to solve the problems insufficient water resources and excessive application of nitrogen fertilizer in this area, this paper explored the irrigation and nitrogen levels that can meet the multiple goals of Isatis indigotica. The two-factor split-plot field experiment (2018‒2019) was conducted in Minle County, Gansu Province, China, which contains 9 treatments. There were three levels of irrigation water: W1(low), W2(medium), and W3(high). The soil moisture contents were 60–70%, 70–80%, and 80–90% of the field water-holding capacity, respectively. The nitrogen application rate was classified into three levels, N1(low), N2(medium) and N3(high), which were 150, 200 and 250 kg N/ha, respectively. The standard local irrigation water amount and nitrogen application rate corresponded to W3N3. The results showed that the yield of Isatis indigotica increased first and then decreased with the increase of irrigation amount and nitrogen application rate, the yield of W2N2 is 12.2–17.1% higher than that of W1N1, the yield of W3N3 was 12.1–17.5% lower than that of W2N2. Saving water and reducing nitrogen can improve the quality of Isatis indigotica, compared with W3N3, the indigo, indirubin, (R,S)-epigoitrin and polysaccharides of W2N2 increased by 4.5–5.9%, 2.7–3.1%, 5.2–6.0%, and 1.8–2.1%, respectively. With the increase of nitrogen application rate, the water use efficiency (WUE) first increased and then decreased, as the irrigation volume increases, WUE decreases. Compared with W3N3, the WUE of W2N2 increased by 24.3–27.2%. With the increase of water input, the nitrogen fertilizer use efficiency (NUE) first increased and then decreased, as the nitrogen application rate increases, NUE decreases. Compared with W3N3, the NUE of W2W2 increased by 31.8–34.5%. Therefore, W2N2 can improve quality and increase water and nitrogen utilization efficiency on the basis of ensuring yield.

Identification and characterization of two Isatis indigotica O-methyltransferases methylating C-glycosylflavonoids.

Isatis indigotica accumulates several active substances, including C-glycosylflavonoids, which have important pharmacological activities and health benefits. However, enzymes catalyzing the methylation step of C-glycosylflavonoids in I. indigotica remain unknown. In this study, three O-methyltransferases (OMTs) were identified from I. indigotica that have the capacity for O-methylation of the C-glycosylflavonoid isoorientin. The Type II OMTs IiOMT1 and IiOMT2 efficiently catalyze isoorientin to form isoscoparin, and decorate one of the aromatic vicinal hydroxyl groups on flavones and methylate the C6, C8, and 3′-hydroxyl positions to form oroxylin A, wogonin, and chrysoeriol, respectively. However, the Type I OMT IiOMT3 exhibited broader substrate promiscuity and methylated the C7 and 3′-hydroxyl positions of flavonoids. Further site-directed mutagenesis studies demonstrated that five amino acids of IiOMT1/IiOMT2 (D121/D100, D173/D149, A174/A150R, N200/N176, and D248/D233) were critical residues for their catalytic activity. Additionally, only transient overexpression of Type II OMTs IiOMT1 and IiOMT2 in Nicotiana benthamiana significantly increased isoscoparin accumulation, indicating that the Type II OMTs IiOMT1 and IiOMT2 could catalyze the methylation step of C-glycosylflavonoid, isoorientin at the 3′-hydroxyl position. This study provides insights into the biosynthesis of methylated C-glycosylflavonoids, and IiOMTs could be promising catalysts in the synthesis of bioactive compounds.

A Systemic Review for Ethnopharmacological Studies on Isatis indigotica Fortune: Bioactive Compounds and their Therapeutic Insights.

Isatis indigotica Fortune is a biennial Chinese woad of the Cruciferae family. It is primarily cultivated in China, where it was a staple in indigo dye manufacture till the end of the 17th century. Today, I. indigotica is used primarily as a therapeutic herb in traditional Chinese medicine (TCM). The medicinal use of the plant is separated into its leaves (Da-Qing-Ye) and roots (Ban-Lan-Gen), whereas its aerial components can be processed into a dried bluish-spruce powder (Qing-Dai), following dehydration for long-term preservation. Over the past several decades, I. indigotica has been generally utilized for its heat-clearing effects and bodily detoxification in TCM, attributed to the presence of several classes of bioactive compounds, including organic acids, alkaloids, terpenoids, and flavonoids, as well as lignans, anthraquinones, glucosides, glucosinolates, sphingolipids, tetrapyrroles, and polysaccharides. This paper aims to delineate I. indigotica from its closely-related species (Isatis tinctoria and Isatis glauca) while highlighting the ethnomedicinal uses of I. indigotica from the perspectives of modern and traditional medicine. A systematic search of PubMed, Embase, PMC, Web of Science, and Google Scholar databases was done for articles on all aspects of the plant, emphasizing those analyzing the bioactivity of constituents of the plant. The various key bioactive compounds of I. indigotica that have been found to exhibit anti-inflammatory, antimicrobial, anticancer, and anti-allergic properties, along with the protective effects against neuronal injury and bone fracture, will be discussed. Collectively, the review hopes to draw attention to the therapeutic potential of I. indigotica not only as a TCM, but also as a potential source of bioactive compounds for disease management and treatment.

Increase in the active ingredients of traditional Chinese medicine Isatis indigotica through iron nanoparticles supplementation versus carbon nanotubes: a comparative study

The low yield and active ingredient content of medicinal plants is always a challenge.

Epigoitrin alleviates lipid and glucose metabolic disorders induced by a high-fat diet.

As living standards improve, obesity has become an increasingly serious health problem. Natural extracts from a wide range of sources are non-toxic and have significant potential as drugs for the prevention and treatment of obesity. We assessed 243 natural small molecules in a HepG2 fat accumulation model and found that epigoitrin (EP) from Radix isatidis reduced intracellular fat deposition, increased short-chain acyl CoA dehydrogenase (SCAD) activity, promoted glucose uptake and glycogen storage, increased ATP production and reduced glutathione (GSH) content, reduced reactive oxygen species (ROS), and enhanced superoxide dismutase (SOD) activity. In a murine high-fat diet model, the addition of EP to the high-fat diet significantly reduced fat deposition, increased glucose tolerance, improved insulin sensitivity, and increased energy expenditure. In conclusion, EP alleviated obesity caused by a high-fat diet and improved disorders of lipid and glucose metabolism.

The alkaloids of Isatis indigotica as promising candidates against COVID-19: A molecular docking simulation for drug development

The alkaloids of Isatis indigotica as promising candidates against COVID-19: A molecular docking simulation for drug development