Traditional Chinese medicine( TCM) processing is a traditional pharmaceutical technology unique to China,which is an important means to ensure the safety and effectiveness of clinical medication. As China' s intangible cultural heritage,it contains a wealth of wisdom. With the evolution and optimization of processing methods,Indigo Naturalis,an ancient dye,has gradually become an effective medicine for the treatment of high fever in children,colitis,psoriasis,and leukemia. However,the quality of Indigo Naturalis pieces is difficult to be fundamentally improved due to the unique traditional processing method,complex technology,unclear principle,and outdated equipment. After spending 20 years in exploring the inheritance,innovation,and transformation of ancient lawtheory-principle-technology-equipment-quality control in Indigo Naturalis processing,our research group has basically expounded the processing principle and realized the modern expression and industrial transformation of traditional technology. As China enters a new era,the TCM industry has begun to undergo the high-quality transformation. It is urgent to carry out new excavations and improve the processing,quality,and clinical application of Indigo Naturalis pieces,to better inherit and innovate traditional processing technologies and meet people's demand for high-quality TCM health services.
Child ; Drugs, Chinese Herbal ; Humans ; Indigo Carmine ; Indigofera ; Medicine, Chinese Traditional ; Psoriasis

The soaking and fermentation of Baphicacanthus cusia( Nees),the important intermediate link of Indigo Naturalis processing,facilitates the synthesis of indigo and indirubin precursors and the dissolution of endogenous enzymes and other effective components,while the role of microorganisms in the fermentation is ignored. The present study investigated the changes of microbial community structure in Indigo Naturalis processing based on 16 S amplicon sequencing and bioinformatics. Meanwhile,the contents of indigo,indirubin,isatin,tryptanthrin,indole glycoside,etc. were determined to explore the correlation between the microorganisms and the alterations of the main components. As demonstrated by the results,the microbial diversity decreased gradually with the fermentation,which bottomed out after the addition of lime. Proteobacteria,Bacteroidetes,and Firmicutes were the main dominant communities in the fermentation. The relative abundance of Proteobacteria declined gradually with the prolongation of fermentation time,and to the lowest level after the addition of lime. The relative abundance of Firmicutes increased,and that of Bacteroidetes decreased first and then increased. The contents of effective substances in Indigo Naturalis also showed different variation tendencies. As fermentation went on,indole glycoside decreased gradually; indigo first increased and then decreased; indirubin and isatin first decreased and then increased; tryptanthrin gradually increased. Those changes were presumedly related to the roles of microorganisms in the synthesis of different components. This study preliminarily clarified the important role of microorganisms in the soaking and fermentation and provided a scientific basis for the control of Indigo Naturalis processing and the preparation of high-quality Indigo Naturalis.
Fermentation ; Indigo Carmine ; Indigofera ; Indoles ; Microbiota

Indigo Naturalis has a long history of medicinal use with particularity and complexity in its processing. Before the Ming dynasty,Indigo Naturalis was extracted from the top layer of zymotic fluid,called " purified Indigo Naturalis". In modern processing,the precipitate " crude Indigo Naturalis" is dried to produce Indigo Naturalis after impurity removal. The form of Indigo Naturalis slices has undergone significant changes in ancient and modern times. In view of this,the quality comparison between crude Indigo Naturalis and purified Indigo Naturalis was conducted in this study with modern analytical techniques. Firstly,chemical composition was analyzed with UPLC-Q-TOF-MS,and the chemical composition of scent with HS-SPME/GC-MS/MS. The content of indigo,indirubin,total ash,and water-soluble extract was determined as well as the inorganic composition in crude Indigo Naturalis and purified Indigo Naturalis. Then,their microscopic morphology was observed and the surface element composition was investigated. Finally,the antipyretic activities of crude Indigo Naturalis and purified Indigo Naturalis were compared in the fever rat model induced by lipopolysaccharide and 2,4-dinitrophenol. The results demonstrated that the purified Indigo Naturalis had a faster and more lasting antipyretic effect,while the crude Indigo Naturalis had almost no antipyretic effect. This study is of great significance to the research on processing technology of Indigo Naturalis and provides reference for the formulation of its quality standards,production specifications and calibration procedures.
Animals ; Indigo Carmine ; Indigofera ; Plant Extracts ; Rats ; Tandem Mass Spectrometry

Indigo Naturalis( IN) is mainly composed of 10% organic matter and 90% inorganic matter,with a poor wettability and strong hydrophobicity. Indigo,indirubin and effective ingredients are almost insoluble in water. And how it exerts its effect after oral administration still needs to be revealed. For this reason,this study put forward the hypothesis that " Indigo Naturalis forms a slightly soluble calcium carbonate carrier in a strong acid environment of gastric fluid,and organic substances are solubilized in the bile environment of intestinal fluid",and then verified the hypothesis. First,the dissolution apparatus was used to simulate the change process of IN in different digestive fluid,and the effects of low-dose and normal bile on the dissolution of inorganic substances and the release of organic substances were compared. After the surface morphology and element changes of IN in different digestive fluid were observed,it was found that bile is the key to promoting the dissolution of organic and inorganic substances in IN. Furthermore,the rat fever model induced by 2,4-dinitrophenol was used to study the antipyretic effect of IN in normal rats and bile duct ligation rats. It was found that the antipyretic effect of IN on normal rats was better than that of bile duct ligation rats. The above results indicated that after oral administration of IN,the calcium carbonate carrier was transformed into a slightly soluble state in acidic gastric fluid,and a small amount of organic matter was released. When IN entered the intestinal fluid mixed with bile,the carrier dissolved in a large amount,and indigo and indirubin were dissolved in a large amount,so as to absorb the blood and exert the effect. This study has a certain significance for guiding clinical application of IN. For patients with insufficient bile secretion( such as bile duct resection),oral administration with IN may not be effective and shall be paid attention.
Animals ; Bile ; Humans ; Hydrophobic and Hydrophilic Interactions ; Indigo Carmine ; Indigofera ; Plant Extracts ; Rats

As an effective antipyretic medicine,Indigo Naturalis has a long history of application in the field of Chinese medicine.The content of organics,mainly indigo and indirubin,is about 10%. However,the active ingredients and mechanism of its antipyretic effect have not yet been fully elucidated. In view of this,they were investigated in this study with the rectal temperature change as an indicator and 2,4-dinitrophenol-induced fever rats as subjects. The content of PGE2 and c AMP in the hypothalamus and the serum levels of TNF-α,IL-1β and IL-6 were determined by ELISA. Moreover,the plasma samples of fever rats were analyzed by metabonomics in combination with UPLC-Q-TOF-MS for the exploration of potential biomarkers and the discussion on the antipyretic mechanism of Indigo Naturalis and its active ingredients. The results showed that the rising trend of rectal temperature in rats was suppressed 0. 5 h after the treatment with Indigo Naturalis,organic matter,indigo or indirubin as compared with the rats of model group( P < 0. 05),among which Indigo Naturalis and organic matter had better antipyretic effect. ELISA results showed that organic matter and indigo can inhibit the expression of PGE2 and c AMP( P<0. 01),while Indigo Naturalis and organic matter were effective in curbing the increase in TNF-α( P<0. 05). A total of 21 endogenous metabolites were identified from the plasma samples of the Indigo Naturalis,organic matter,indigo and indirubin groups,which were mainly involved in glycerophospholipid metabolism.
2,4-Dinitrophenol ; Animals ; Antipyretics ; Drugs, Chinese Herbal ; Indigo Carmine ; Indigofera ; Rats

Polyethylene glycol (PEG) surface film-forming method was used to prepare hydrophilic Indigo Naturalis decoction pieces with stable effect.The preparation process of modified Indigo Naturalis was optimized and its microscopic properties,hydrophilicity,antipyretic efficacy,and safety were systematically evaluated.With equilibrium contact angle as assessment index,the influence of modifier type,modifier dosage,dispersant dosage,and co-grinding time on water solubility of Indigo Naturalis was investigated by single factor test.The results showed that the optimal preparation process was as follows.The 6%PEG6000 is dissolved in 10%anhydrous ethanol solution by sonification and then the mixture is ground with Indigo Naturalis for 2 min.The resultant product is dried on a square tray in an oven at 60℃to remove ethanol and thereby the PEG-modified hydrophilic Indigo Naturalis decoction pieces are yielded.The morphological observation under scanning electron microscope (SEM) indicated that the modified Indigo Naturalis had smoother surface than Indigo Naturalis,and energy spectrometer measurement showed that the nitrogen (N),calcium(Ca),oxygen (O),and silicon (Si) on the surface of modified Indigo Naturalis powder were less than those of Indigo Naturalis powder.Modified Indigo Naturalis had the equilibrium contact angle 18.96°smaller,polar component 22.222 m J·m~(-2)more,and nonpolar component 7.277 m J·m~(-2)smaller than the Indigo Naturalis powder.Multiple light scattering technique was employed to evaluate the dispersion in water and the result demonstrated that the transmittance of Indigo Naturalis and modified Indigo Naturalis was about85%and 75%,respectively,suggesting the higher dispersity of modified Indigo Naturalis.The suspension rate of modified Indigo Naturalis in water was determined by reflux treatment.The result showed that 57%of Indigo Naturalis was not wetted after refluxing for1 h,while the modified Indigo Naturalis was all wetted and dispersed into water.The dissolution of indigo and indirubin of modified Indigo Naturalis increased and the process was more stable.Then,rats were randomized into the blank group,model group,acetaminophen group,Indigo Naturalis group,and hydrophilic Indigo Naturalis group.The temperature changes of rats were observed after administration and the concentration of IL-1βand TNF-αin serum and IL-1βand PGE_2in hypothalamus was measured.The results indicated that the temperature of Indigo Naturalis group and hydrophilic Indigo Naturalis group dropped and the IL-1βlevel of the hydrophilic Indigo Naturalis group decreased (P<0.05) as compared with those in the model group.Thus,both Indigo Naturalis and hydrophilic Indigo Naturalis had antipyretic effect,particularly the hydrophilic Indigo Naturalis.The acute toxicity test of hydrophilic Indigo Naturalis verified that it had no toxicity to rats.In this study,the hydrophilic Indigo Naturalis decoction pieces were prepared with the PEG surface film-forming method,and the antipyretic efficacy and safety were evaluated,which expanded the technological means of powder modification for Chinese medicine and provided a method for clinical use of Chinese medicine.
Animals ; Drugs, Chinese Herbal ; Hydrophobic and Hydrophilic Interactions ; Indigo Carmine ; Indigofera ; Polyethylene Glycols ; Rats

Eleven condensed tannins were isolated from the roots of Indigofera stachyodes by various column chromatography techniques including silica gel, octadecyl silica(ODS), Sephadex LH-20, and semi-preparative high performance liquid chromatography(HPLC). These compounds were identified on the basis of physicochemical properties, nuclear magnetic resonance(NMR) and mass spectrometry(MS) data as stachyotannin A(1), epicatechin-(2β→O→7,4β→8)-epiafzelechin-(4β→8)-catechin(2), cinnamtannin D1(3), cinnamtannin B1(4), epicatechin-(2β→O→7,4β→8)-epiafzelechin-(4α→8)-epicatechin(5), gambiriin C(6), proanthocyanidin A1(7), proanthocyanidin A2(8), aesculitannin B(9), proanthocyanidin A4(10), and procyanidin B5(11). Compound 1 is a new compound. Compounds 2-11 were isolated from Indigofera for the first time. Furthermore, compounds 1, 2, and 4-11 showed inhibitory effects on thrombin-induced ATP release in platelets.
Chromatography, High Pressure Liquid ; Indigofera ; Magnetic Resonance Spectroscopy ; Plant Extracts ; Proanthocyanidins

Natural indigo, as one of the oldest dyes, is also a pivotal dye utilized in cotton fabrics today. A diversity of plants rich in indigo compounds belong to traditional Chinese herbal medicines. Indigo compounds have a variety of biological and pharmacological activities, including anticonvulsant, antibacterial, antifungal, antiviral and anticancer activities. A substantial progress in indigo biosynthesis has been made lately. This paper summarizes the value of indigo from the aspects of cultural history, biosynthetic pathways and the medicinal activities of its related derivatives involved in the pathways. In addition, the latest research advancements in indigo biosynthetic pathways is demonstrated in this paper, which would lay the theoretical foundation for the exploration and utilization of natural indigo.
Biosynthetic Pathways ; Coloring Agents ; Indigo Carmine/metabolism* ; Indigofera/metabolism*

For the discussion of the source, preparation and quality problems of Indigo Naturalis, the historical tradition and reality were summarized by literature survey and producing area investigation. Besides some quality problems, potential safety hazards were found out in some samples from market tested. Because lime could not be dislodged enough from Indigo Naturalis in the process of purification, the samples of Indigo Naturalis contained too much lime and showed strong alkalinity. It was suggested that the quality standard of Indigo Naturalis should be revised and revised and some detection projects and methods should be added into the standard. In addition, we suggested that the production access of Indigo Naturalis should be further defined.
Drugs, Chinese Herbal ; standards ; Indigofera ; chemistry ; Plants, Medicinal ; chemistry

OBJECTIVETo compare and elucidate the antioxidant efficacy of ethanolic and hydroethanolic extracts of Indigofera tinctoria Linn. (Fabaceae family).

METHODSVarious in-vitro antioxidant assays and free radical-scavenging assays were done. Quantitative measurements of various phytoconstituents, reductive abilities and chelating potential were carried out along with standard compounds. Half inhibitory concentration (IC50) values for ethanol and hydroethanol extracts were analyzed and compared with respective standards.

RESULTSHydroethanolic extracts showed considerably more potent antioxidant activity in comparison to ethanol extracts. Hydroethanolic extracts had lower IC50 values than ethanol extracts in the case of DPPH, metal chelation and hydroxyl radical-scavenging capacity (829, 659 and 26.7 μg/mL) but had slightly higher values than ethanol in case of SO2- and NO2-scavenging activity (P<0.001 vs standard). Quantitative measurements also showed that the abundance of phenolic and flavonoid bioactive phytoconstituents were significantly (P<0.001) greater in hydroethanol extracts (212.920 and 149.770 mg GAE and rutin/g of plant extract respectively) than in ethanol extracts (211.691 and 132.603 mg GAE and rutin/g of plant extract respectively). Karl Pearson's correlation analysis (r2) between various antioxidant parameters and bioactive components also associated the antioxidant potential of I. tinctoria with various phytoconstituents, especially phenolics, flavonoids, saponins and tannins.

CONCLUSIONThis study may be helpful to draw the attention of researchers towards the hydroethanol extracts of I. tinctoria, which has a high yield, and great prospects in herbal industries to produce inexpensive and powerful herbal products.