Strobilanthes cusia (Nees) Kuntze, a multifunctional traditional Chinese medicinal plant, and its herbal medicines: A comprehensive review

"Purplish Blue" or "Greenish Grey"? Indigo Qualities and Extraction Yields from Six Species

Indigo quality is determined by its indigotin content. Another quality indicator is colour. For an evaluation of species, indigo samples from Indigofera tinctoria, Indigofera suffruticosa, Indigofera arrecta, Persicaria tinctoria, Strobilanthes cusia and Wrightia laevis cultivated in Austria and China were visually classified and analysed spectrophotometrically and using a L*a*b* measuring device. In addition to a standardised hot-extraction method without lime, some samples were extracted simulating traditional methods at ambient temperatures using lime. The highest indigotin contents were achieved with Indigofera arrecta (55%, Austria) and Strobilanthes cusia (56%, China). There were no statistically significant differences between the indigo extraction yields of the species cultivated in Austria, but Indigofera arrecta and Persicaria tinctoria had statistically significantly higher indigotin extraction yields than Indigofera tinctoria and Indigofera suffruticosa. From the species extracted in China, Strobilanthes cusia showed higher values in all parameters than Indigofera tinctoria, Indigofera suffruticosa and Wrightia laevis. Compared with the standardised method, the method simulating local practice yielded more indigo but had a lower indigotin content; the indigotin extraction yields did not differ greatly. L*a*b* values enabled precise estimations of the indigotin content, making it an interesting option for quality control, as inexpensive, easy-to-handle L*a*b* measuring instruments have become available.

An alkaloid-rich phytopharmaceutical prepared from Qing Dai against IL-17A-induced psoriasis

ETHNOPHARMACOLOGICAL RELEVANCE

Psoriasis is a chronic inflammatory disease due to immune dysregulation that cannot be cured. The skin conditions of psoriasis negatively impact patients' quality of life worldwide. Qing Dai (Indigo Naturalis), a traditional Chinese medicine (TCM) processed from Strobilanthes cusia is a clinical medicine used for psoriasis patient in Taiwan and the gene overexpression of interleukin (IL)-17A could be notably reduced in skin lesions after using Qing Dai ointment and its alkaloid ingredients.

AIM OF THE STUDY

To develop a potential anti-psoriatic phytopharmaceutical, an alkaloid-rich fraction named INM-A was prepared from Qing Dai. The chemical profile and anti-psoriatic activity of INM-A were analyzed and evaluated to define its in vitro mechanism and in vivo efficacy for psoriasis therapy.

MATERIALS AND METHODS

Dowex® 50WX4 hydrogen form resin was used for column chromatography to prepare INM-A. To track alkaloids, INM-A was conducted with Dragendorff's, Mayer's, and Wagner's reagents. HPLC and UV-Vis spectrophotometer were applied to analyze the chemical profile and relative total alkaloid content in INM-A. A psoriatic mouse model induced by imiquimod (IMQ) was performed to verify in vivo efficacy of INM-A. IL-17A-dominated cellular oxygen consumption rate, oxidative stress, and cytokines in keratinocytes were measured to clarify in vitro mechanism of INM-A.

RESULTS

An alkaloid-rich fraction, INM-A, consisted of seven active alkaloid compounds 1-7 was obtained from Qing Dai. INM-A improved the skin condition severities in IMQ-induced psoriatic mice and decreased IL-17A in not only psoriatic mice but also polarized Th17 cells. In addition, INM-A targeted IL-17A to inhibit inflammation and OXPHOS-driven oxidative stress in human keratinocytes.

CONCLUSION

Accordingly, INM-A manufactured from Qing Dai may be a promising lead phytopharmaceutical for further IL-17A-related inflammatory disease studies such as psoriasis.

Screening and identification of neuraminidase inhibitors from Baphicacanthus cusia by a combination of affinity ultrafiltration, HPLC-MS/MS, molecular docking, and fluorescent techniques

Natural products provide a new opportunity for the discovery of neuraminidase (NA)inhibitors. In this study, an affinity ultrafiltration (AUF) coupled with HPLC-MS/MS method was firstly developed and optimized for screening of NA inhibitors from natural products. The critical factors influencing the interaction of enzyme-ligand (including sample concentration, enzyme concentration, incubation time and temperature, pH of the buffer, and dissociation solvents and time) were investigated and optimized by a one-factor-at-a-time design. The method was then applied to discover NA inhibitory compounds in stems and leaves of Baphicacanthus cusia. As a result, five active alkaloids were screened out and identifiedas 2,4(1H,3H)-quinazolinedione (1), 4(3H)-quinazolinone (2), 2(3H)-benzoxazolone (3), tryptanthrin (4), and indirubin (5) through analysis of their DAD profiles, MS/MS fragments, and comparison with reference substances. These active compounds were further evaluated for their NA inhibitory activity using a fluorescence-based NA inhibition assay. The result from the fluorescent assay revealed that all the five compounds(1-5) showed pronounced NA inhibitory activities with IC50values of 98.98, 64.69, 40.16, 69.44, and 144.73 μM, respectively. Finally, molecular docking of these five alkaloids with NA showed that hydrogen bond and π-cation interactions dominated within the binding sites with binding energies ranging between -5.7 to -7.9 kcal/mol, which was supported by the results of the AUF and the fluorescence-based enzyme assay. The developed AUF method is simple and efficient for screening potential NA inhibitors from stems and leaves of B. cusia.

Integrated Network Pharmacology, Molecular Docking and Animal Experiment to Explore the Efficacy and Potential Mechanism of Baiyu Decoction Against Ulcerative Colitis by Enema

Background

Baiyu Decoction (BYD), a clinical prescription of traditional Chinese medicine, has been proven to be valuable for treating ulcerative colitis (UC) by enema. However, the mechanism of BYD against UC remains unclear.

Purpose

A combination of bioinformatics methods including network pharmacology and molecular docking and animal experiments were utilized to investigate the potential mechanism of BYD in the treatment of UC.

Materials and Methods

Firstly, the representative compounds of each herb in BYD were detected by liquid chromatography-mass spectrometry. Subsequently, we predicted the core targets and potential pathways of BYD for treating UC through network pharmacology. And rat colitis model was established with dextran sodium sulfate. UC rats were subjected to BYD enema administration, during which we recorded body weight changes, disease activity index, and colon length to assess the effectiveness of BYD. Besides, quantitative real-time PCR, western blotting, ELISA and immunofluorescence were used to detect intestinal inflammatory factors, intestinal barrier biomarkers and TOLL-like receptor pathway in rats. Finally, the core components and targets of BYD were subjected to molecular docking so as to further validate the results of network pharmacology.

Results

A total of 41 active compositions and 203 targets related to BYD-UC were subjected to screening. The results of bioinformatics analysis showed that quercetin and kaempferol may be the main compounds. Additionally, AKT1, IL-6, TP53, TNF and IL-1β were regarded as potential therapeutic targets. KEGG results explained that TOLL-like receptor pathway might play a pivotal role in BYD protecting against UC. In addition, animal experiments and molecular docking validated the network pharmacology results. BYD enema treatment can reduce body weight loss, lower disease activity index score, reverse colon shortening, relieve intestinal inflammation, protect intestinal barrier, and inhibit TOLL-like receptor pathway in UC rats. Besides, molecular docking suggested that quercetin and kaempferol docked well with TLR4, AKT1, IL-6, TP53.

Conclusion

Utilizing network pharmacology, animal studies, and molecular docking, enema therapy with BYD was confirmed to have anti-UC efficacy by alleviating intestinal inflammation, protecting the intestinal barrier, and inhibiting the TOLL-like receptor pathway. Researchers should focus not only on oral medications but also on the rectal administration of medications in furtherance of the cure of ulcerative colitis.

Identification of novel flavin-dependent monooxygenase from Strobilanthes Cusia reveals molecular basis of indoles' biosynthetic logic

BACKGROUND

Strobilanthes cusia (Nees) Kuntze is a traditional medical plant distributed widely in south China. The indole compounds that originated from the plant are responsible for its pharmacological activities. However, the reason why indole ingredients are accumulated in this herb and how it is biosynthesized has remained largely unknown.

RESULTS

In this study, metabolic and transcriptional profiling measurement experiments of different S. cusia organs were carried out to understand the underlying molecular basis of indoles' biosynthetic logic. A metabolic investigation demonstrated that the indoles are primarily accumulated mainly in aerial parts, particularly in leaves. RNA-seq was employed to reveal the organ specific accumulation of indoles in different S. cusia organs. Meanwhile, a flavin-dependent monooxygenase gene (ScFMO1) was found in S. cusia, and it has capacity to produce indoxyl from indole by the fermentation assay. Finally, we assessed the outcomes of transient expression experiment in tobacco and confirmed that ScFMO1 localizes in cytoplasm.

CONCLUSIONS

Our results suggest that ScFMO1 plays a key role in biosynthesis of indoles (Indigo, indirubin, indican, etc.), it will be useful for illuminating the molecular basis of the medicinal indoles' biosynthesis and developing strategies for improving their yields.

Discrimination of Baphicacanthis Cusiae Rhizoma et radix and its adulterant species and establishment of an assay method for quality control

BACKGROUND

Baphicacanthis Cusiae Rhizoma et Radix, commonly known as Nan-Ban-Lan-Gen (NBLG), is an essential traditional Chinese medicine that possesses diverse bioactivities, particularly noteworthy for its antiviral properties. Although NBLG has been listed in the Chinese Pharmacopoeia as an independent Chinese medicine, the establishment of a comprehensive quality standard for NBLG remains elusive. The absence of assay for marker compound in its quality standards has led to the lack of corresponding quality control measures for NBLG-containing preparations, and its discrimination from adulterant species in the market which thereby can significantly impact the efficacy and safety of NBLG-containing products.

METHODS

Ultra-high performance liquid chromatography (UHPLC) coupled with quadrupole-time-of-flight mass spectrometry (Q-TOF-MS) was employed for comprehensive profiling of the chemical constituents of NBLG, the stem of Baphicacanthus cusia (Nees) Bremek (NBLJ), and the roots of Isatis indigotica Fort. (Bei-Ban-Lan-Gen, BBLG). Additionally, multivariate analysis was conducted to compare the chemical components of NBLG with those of NBLJ and BBLG. Furthermore, we established an optimized and validated HPLC method to obtain the fingerprint of NBLG and quantify the content of 2-benzoxazolinone and acteoside in the samples.

RESULTS

A total of 73 compounds belonging to six classes were assigned in NBLG, with alkaloids being the most abundant and diverse species. High compositional similarities with significant differences in content were observed between NBLG and NBLJ. Moreover, the chemical profile of BBLG markedly differed from that of NBLG. An informative high performance liquid chromatography (HPLC) fingerprint of NBLG comprising seven characteristic peaks that can be used for quality assessment was established. Notably, we propose a quality control standard for NBLG, stipulating that the limit of content in dry weight for both 2-benzoxazolinone and acteoside should not be less than 0.010%.

CONCLUSION

This study provides the most comprehensive chemical information to date on NBLG, offering valuable insights into its authentication and quality control. Our findings highlight the importance of comprehensive chemical profiling to differentiate potential substitutions and adulterations of herbal medicines, particularly when the original source is scarce or unavailable. These results can aid in the development of quality control measures for NBLG-containing preparations, ensuring their safety and efficacy.

Combining the In Silico and In Vitro Assays to Identify Strobilanthes cusia Kuntze Bioactives against Penicillin-Resistant Streptococcus pneumoniae

Leaves of Strobilanthes cusia Kuntze (S. cusia) are a widely used alexipharmic Traditional Chinese Medicine (TCM) in southern China for the prevention of cold and respiratory tract infectious diseases. One of the most common bacterial pathogens in the respiratory tract is the gram-positive bacterium Streptococcus pneumoniae. The antibiotic resistance of colonized S. pneumoniae makes it a more serious threat to public health. In this study, the leaves of S. cusia were found to perform antibacterial effects on the penicillin-resistant S. pneumoniae (PRSP). Confocal assay and Transmission Electron Microscopy (TEM) monitored the diminished cell wall integrity and capsule thickness of the PRSP with treatment. The following comparative proteomics analysis revealed that the glycometabolism-related pathways were enriched for the differentially expressed proteins between the samples with treatment and the control. To further delve into the specific single effective compound, the bio-active contents of leaves of S. cusia were analyzed by UPLC-UV-ESI-Q-TOF/MS, and 23 compounds were isolated for anti-PRSP screening. Among them, Tryptanthrin demonstrated the most promising effect, and it possibly inhibited the N-glycan degradation proteins, as suggested by reverse docking analysis in silico and further experimental verification by the surface plasmon resonance assay (SPR). Our study provided a research foundation for applications of the leaves of S. cusia as a TCM, and supplied a bio-active compound Tryptanthrin as a candidate drug skeleton for infectious diseases caused by the PRSP.

Psoriasis treatment using Indigo Naturalis: Progress and strategy

ETHNOPHARMACOLOGICAL RELEVANCE

In recent years, there are increasing that the number of patients with psoriasis day by day, and it has become a common disease endangering public health. However, there is no specific cure for psoriasis or control of recurrence. Therefore, it's necessity to seek alternative and efficient therapy, such as Traditional Chinese Medicine (TCM). As a TCM and effective medicine for the treatment of psoriasis, Indigo Naturalis (Baphicacanthus Cusia (Nees) Bremek.) has the effect of clearing heat, detoxifying blood, eliminating spots, reducing fire and calming panic, and it is used in many classical prescriptions for the treatment of psoriasis.

AIM OF REVIEW

To review the latest progress and strategies of Indigo Naturalis in the treatment of psoriasis. This manuscript mainly clarifies the traditional medicinal applications, the mechanism of action and application strategies of Indigo Naturalis, and its preparations in the treatment of psoriasis.

MATERIALS AND METHODS

Detailed information on Indigo Naturalis was collected from various online databases (PubMed, GeenMedical, Web of Science, Google Scholar, China National Knowledge Infrastructure Database, and National Intellectual Property Administration).

RESULTS

This manuscript reviews a great deal of information about how Indigo Naturalis can treat psoriasis through immune cells, signal pathways and disease-related mediators. The mechanism of cymbididae is expounded from the aspects of regulating keratinocyte proliferation and differentiation, regulating inflammatory infiltration of cellular immune system and improving microvascular dilation and hyperplasia in skin lesions.

CONCLUSION

The action mechanisms of Indigo Naturalis on psoriasis reflect the characteristics of multiple components, multiple targets, and multiple pathways of Traditional Chinese medicine. However, some pharmacological and clinical research methods are improper, so that the results are difficult to explain at present. Therefore, further in-depth research is needed to provide knowledge in a wider range of areas to confirm the great therapeutic potential of Indigo Naturalis.

The current status of old traditional medicine introduced from Persia to China

Traditional Chinese medicine (TCM) includes over ten thousand herbal medicines, some of which were introduced from outside countries and territories. The Silk Road enabled the exchange of merchandise such as teas, silks, carpets, and medicines between the East and West of the Eurasia continent. During this time, the ‘Compendium of Materia Medica’ (CMM) was composed by a traditional medicine practitioner, Shizhen Li (1,518–1,593) of the Ming Dynasty. This epoch-making masterpiece collected knowledge of traditional medical materials and treatments in China from the 16th century and before in utmost detail, including the origin where a material was obtained. Of 1892 medical materials from the CMM, 46 came from Persia (now Iran). In this study, the basic information of these 46 materials, including the time of introduction, the medicinal value in TCM theory, together with the current status of these medicines in China and Iran, are summarized. It is found that 20 herbs and four stones out of the 46 materials are registered as medicinal materials in the latest China Pharmacopoeia. Now most of these herbs and stones are distributed in China or replacements are available but saffron, ferula, myrrh, and olibanum are still highly dependent on imports. This study may contribute to the further development, exchange, and internationalization of traditional medicine of various backgrounds in the world, given the barriers of transportation and language are largely eased in nowadays.

Effect of Strobilanthes tonkinensis Lindau Addition on Black Tea Flavor Quality and Volatile Metabolite Content

The characteristic aroma of Chinese black tea (BT) produced in summer usually lacks intensity and persistence, reducing consumer acceptance and market demand. Strobilanthes tonkinensis Lindau (STL) possesses excellent biological characteristics, making it a promising novel tea ingredient. We investigated the effects of different addition methods and concentrations for the novel additive STL on the sensory quality of BT. A 20:1500 g/g addition to rolled tea leaves was identified as the best BT with STL (BoS) treatment. We identified 141 volatile metabolites (VMs) for the first time in STL, with high alcohol, ester, ketone, enyne, alkyne, and alkane contents. Partial least-squares discriminant analysis distinguished the samples and revealed 28, 26, and 14 differential VMs in STL vs. BoS, BT vs. STL, and BT vs. BoS comparisons, respectively. Using a combination of Venn, multiple experiment viewer, and odor activity value analysis, 16 key differential VMs were identified. Compared to BT, the 1-octen-3-ol, 1-hexanol, 1-dodecanol, (E)-3-hexen-1-ol, phenylethyl alcohol, and 2-methoxy-3-(2-methylpropyl)-pyrazine contents in BoS were 394.7%, 53.6%, 34.1%, 24.4%, 9.9%, and 5.7% higher, respectively. BoS combined the aromatic properties of BT and STL into a sweet and glutinous rice flavor. The results provide theoretical support for future research and development of novel BT-based products.

Ethnoveterinary Survey Conducted in Baiku Yao Communities in Southwest China

Baiku Yao is a branch of the Yao ethnic group mainly living in Guangxi and Guizhou provinces of China. They are recognized by UNESCO as an ethnic group with an intact ethnic culture. The Baiku Yao people have extensive ethnoveterinary knowledge, which they used to prevent and control various animal diseases. During the African swine fever outbreak, the livestock of the Baiku Yao community remained unaffected. We investigated ethnoveterinary knowledge among local Baiku Yao villagers. A total of 39 ethnoveterinary plant species are utilized for the treatment of various diseases. Five species, namely, Stephania kwangsiensis, Aristolochia kwangsiensis, Clerodendrum bungei, Paederia foetida, and Tetradium ruticarpum, had the highest relative frequency values. Strobilanthes cusia, Tetradium ruticarpum, and Stephania kwangsiensis are highly valued locally for treating animal plagues. The existing traditional ethnoveterinary knowledge needs to be conserved and validated scientifically.

Detoxification II Prescription Suppresses the Th-17/IL-17 Inflammatory Axis to Improve the Liver Function of ACLF-Rats via Inactivating the P38MAPK Pathway

Hepatitis is a metabolic system disease which is a serious challenge to the medical and healthcare system of the world. This study attempted to investigate the therapeutic effect and illustrate the regulation pharmacological mechanism of Detoxification II Prescription on ACLF. In this study, the rats were injected with D-galactosamine to establish ACLF-rat models, and the levels of cholinesterase (CHE), alanine aminotransferase (ALT), aspartate aminotransferase (AST), albumin (ALB), and total bilirubin (TBiL) were measured with the related kits to reflect the liver functions of the rats. The levels of IL-17, IL-6, and IFN-γ in the serums of the rats were detected by qRT-PCR, and the percentages of Th-17 cells in CD4⁺ cells of the rats were measured by flow cytometry assay. In the results, the increased ALT, AST, TBiL, IL-6, IL-17, IFN-γ, and percentage of Th-17 cells in CD4⁺ and decreased ALB and CHE were found in the serums of the ACLF-rats, while Detoxification II Prescription could partly reverse those indexes of the ACLF-rats. Moreover, it was also found that Detoxification II Prescription could inhibit the expression of P38MAPK, and P38MAPK downregulation obviously improved the liver function indexes of the ACLF-rats including the levels of ALT, AST, TBiL, IL-6, IL-17, IFN-γ, and percentage of Th-17 cells in CD4⁺ cells. In conclusion, this study suggested that Detoxification II Prescription could suppress the Th-17/IL-17 inflammatory axis to improve the liver function of ACLF-rats via inhibiting the activity of the P38MAPK pathway.

Network pharmacology study on the mechanism of the Chinese medicine Radix Isatidis (Banlangen) for COVID-19

Radix Isatidis (Banlangen) is a well-known traditional Chinese medicine for the treatment of different diseases and prevention of many body disorders. Besides, it also plays a pivotal role in novel coronavirus pneumonia, coronavirus disease 2019 (COVID-19). However, few researchers know its active ingredients and mechanism of action for COVID-19. To find whether Banlangen has a pharmacological effect on COVID-19. In this research, we systematically analyze Banlangen and COVID-19 through network pharmacology technology. A total of 33 active ingredients in Banlangen, 92 targets of the active ingredients, and 259 appropriate targets of COVID-19 were obtained, with 11 common targets. The analysis of the biological process of gene ontology and the enrichment of Kyoto Encyclopedia of Genes and Genomes signaling pathway suggests that Banlangen participated in the biological processes of protein phosphatase binding, tetrapyrrole binding, the apoptotic process involving cysteine-type endopeptidase activity, etc. The COVID-19 may be treated by regulating advanced glycation end products/a receptor for advanced glycation end products signaling pathway, interleukin-17 signaling pathway, tumor necrosis factor signaling pathway, sphingolipid signaling pathway, and p53 signaling pathway. Banlangen has a potential pharmacological effect on COVID-19, which has the value of further exploration in the following experiment and clinical application.

Electrochemical Fingerprint Biosensor for Natural Indigo Dye Yielding Plants Analysis

Indigo is a plant dye that has been used as an important dye by various ancient civilizations throughout history. Today, due to environmental and health concerns, plant indigo is re-entering the market. Strobilanthes cusia (Nees) Kuntze is the most widely used species in China for indigo preparation. However, other species under Strobilanthes have a similar feature. In this work, 12 Strobilanthes spp. were analyzed using electrochemical fingerprinting technology. Depending on their electrochemically active molecules, they can be quickly identified by fingerprinting. In addition, the fingerprint obtained under different conditions can be used to produce scattered patter and heatmap. These patterns make plant identification more convenient. Since the electrochemically active components in plants reflect the differences at the gene level to some extent, the obtained electrochemical fingerprints are further used for the discussion of phylogenetics.

High-Quality Genome of the Medicinal Plant Strobilanthes cusia Provides Insights Into the Biosynthesis of Indole Alkaloids

Strobilanthes cusia (Nees) Kuntze is an important plant used to process the traditional Chinese herbal medicines "Qingdai" and "Nanbanlangen". The key active ingredients are indole alkaloids (IAs) that exert antibacterial, antiviral, and antitumor pharmacological activities and serve as natural dyes. We assembled the S. cusia genome at the chromosome level through combined PacBio circular consensus sequencing (CCS) and Hi-C sequencing data. Hi-C data revealed a draft genome size of 913.74 Mb, with 904.18 Mb contigs anchored into 16 pseudo-chromosomes. Contig N50 and scaffold N50 were 35.59 and 68.44 Mb, respectively. Of the 32,974 predicted protein-coding genes, 96.52% were functionally annotated in public databases. We predicted 675.66 Mb repetitive sequences, 47.08% of sequences were long terminal repeat (LTR) retrotransposons. Moreover, 983 Strobilanthes-specific genes (SSGs) were identified for the first time, accounting for ~2.98% of all protein-coding genes. Further, 245 putative centromeric and 29 putative telomeric fragments were identified. The transcriptome analysis identified 2,975 differentially expressed genes (DEGs) enriched in phenylpropanoid, flavonoid, and triterpenoid biosynthesis. This systematic characterization of key enzyme-coding genes associated with the IA pathway and basic helix-loop-helix (bHLH) transcription factor family formed a network from the shikimate pathway to the indole alkaloid synthesis pathway in S. cusia. The high-quality S. cusia genome presented herein is an essential resource for the traditional Chinese medicine genomics studies and understanding the genetic underpinning of IA biosynthesis.

Beneficial effect of Indigo Naturalis on acute lung injury induced by influenza A virus

Background

Infections induced by influenza viruses, as well as coronavirus disease 19 (COVID-19) pandemic induced by severe acute respiratory coronavirus 2 (SARS-CoV-2) led to acute lung injury (ALI) and multi organ failure, during which traditional Chinese medicine (TCM) played an important role in treatment of the pandemic. The study aimed to investigate the effect of Indigo Naturalis on ALI induced by influenza A virus (IAV) in mice.

Method

The anti-influenza and anti-inflammatory properties of aqueous extract of Indigo Naturalis (INAE) were evaluated in vitro. BALB/c mice inoculated intranasally with IAV (H1N1) were treated intragastrically with INAE (40, 80 and 160 mg/kg/day) 2 h later for 4 or 7 days. Animal lifespan and mortality were recorded. Expression of high mobility group box-1 protein (HMGB-1) and toll-like receptor 4 (TLR4) were evaluated through immunohistological staining. Inflammatory cytokines were also monitored by ELISA.

Result

INAE inhibited virus replication on Madin-Darby canine kidney (MDCK) cells and decreased nitric oxide (NO) production from lipopolysaccharide (LPS)-stimulated peritoneal macrophages in vitro. The results showed that oral administration of 160 mg/kg of INAE significantly improved the lifespan (P < 0.01) and survival rate of IAV infected mice, improved lung injury and lowered viral replication in lung tissue (P < 0.01). Treatment with INAE (40, 80 and 160 mg/kg) significantly increased liver weight and liver index (P < 0.05), as well as weight and organ index of thymus and spleen at 160 mg/kg (P < 0.05). Serum alanine transaminase (ALT) and aspartate aminotransferase (AST) levels were reduced by INAE administration (P < 0.05). The expression of HMGB-1 and TLR4 in lung tissue were also suppressed. The increased production of myeloperoxidase (MPO) and methylene dioxyamphetamine (MDA) in lung tissue were inhibited by INAE treatment (P < 0.05). Treatment with INAE reduced the high levels of interferon α (IFN-α), interferon β (IFN-β), monocyte chemoattractant protein-1 (MCP-1), regulated upon activation normal T cell expressed and secreted factor (RANTES), interferon induced protein-10 (IP-10), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) (P < 0.05), with increased production of interferon γ (IFN-γ) and interleukin-10 (IL-10) (P < 0.05).

Conclusion

The results showed that INAE alleviated IAV induced ALI in mice. The mechanisms of INAE were associated with its anti-influenza, anti-inflammatory and anti-oxidation properties. Indigo Naturalis might have clinical potential to treat ALI induced by IAV.

From natural dye to herbal medicine: a systematic review of chemical constituents, pharmacological effects and clinical applications of indigo naturalis

Background

Indigo naturalis is a blue dye in ancient, as well as an extensive used traditional Chinese medicine. It has a wide spectrum of pharmacological properties and can be used to treat numerous ailments such as leukemia, psoriasis, and ulcerative colitis. This article aims to expand our understanding of indigo naturalis in terms of its chemical constituents, pharmacological action and clinical applications.

Methods

We searched PubMed, web of science, CNKI, Google academic, Elsevier and other databases with the key words of “Indigo naturalis”, and reviewed and sorted out the modern research of indigo naturalis based on our research results.

Results

We outlined the traditional manufacturing process, chemical composition and quality control of indigo naturalis, systematically reviewed traditional applictions, pharmacological activities and mechanism of indigo naturalis, and summarized its clinical trials about treatment of psoriasis, leukemia and ulcerative colitis.

Conclusions

Indigo naturalis has a variety of pharmacological activities, such as anti-inflammatory, antioxidant, antibacterial, antiviral, immunomodulatory and so on. It has very good clinical effect on psoriasis, leukemia and ulcerative colitis. However, it should be noted that long-term use of indigo naturalis may produce some reversible adverse reactions. In summarize, indigo naturalis is an extremely important drug with great value and potential.