Indigo dyes: Toxicity, teratogenicity, and genotoxicity studies in zebrafish embryos.

Wastewater released by textile dyeing industries is a major source of pollution. Untreated wastewater released from indigo dyeing operations affects aquatic ecosystems and threatens their biodiversity. We have assessed the toxicity of natural and synthetic indigo dye in zebrafish embryos, using the endpoints of teratogenicity, genotoxicity, and histopathology. The zebrafish embryo toxicity test (ZFET) was conducted, exposing embryos to ten concentrations of natural and synthetic indigo dyes; the 96-hour LC50 values were approximately 350 and 300 mg/L, respectively. Both dyes were teratogenic, causing egg coagulation, tail detachment, yolk sac edema, pericardial edema, and tail bend, with no significant difference in effects between the natural and synthetic dyes. Both dyes were genotoxic (using comet assay for DNA damage). Real-time RT-PCR studies showed upregulation of the DNA-repair genes FEN1 and ERCC1. Severe histological changes were seen in zebrafish larvae following exposure to the dyes. Our results show that indigo dyes may be teratogenic and genotoxic to aquatic organisms, underscoring the need for development of sustainable practices and policies for mitigating the environmental impacts of textile dyeing.

Overview of indigo biosynthesis by Flavin-containing Monooxygenases: History, industrialization challenges, and strategies.

Indigo is a natural dye extensively used in the global textile industry. However, the conventional synthesis of indigo using toxic compounds like aniline, formaldehyde, and hydrogen cyanide has led to environmental pollution and health risks for workers. This method also faces growing economic, sustainability, and environmental challenges. To address these issues, the concept of bio-indigo or indigo biosynthesis has been proposed as an alternative to aniline-based indigo synthesis. Among various enzymes, Flavin-containing Monooxygenases (FMOs) have shown promise in achieving a high yield of bio-indigo. However, the industrialization of indigo biosynthesis still encounters several challenges. This review focuses on the historical development of indigo biosynthesis mediated by FMOs. It highlights several factors that have hindered industrialization, including the use of unsuitable chassis (Escherichia coli), the toxicity of indole, the high cost of the substrate L-tryptophan, the water-insolubility of the product indigo, the requirement of reducing reagents such as sodium dithionite, and the relatively low yield and high cost compared to chemical synthesis. Additionally, this paper summarizes various strategies to enhance the yield of indigo synthesized by FMOs, including redundant sequence deletion, semi-rational design, cheap precursor research, NADPH regeneration, large-scale fermentation, and enhancement of water solubility of indigo.

NiAlFe LTH /MoS2 p-n junction heterostructure composite as an effective visible-light-driven photocatalyst for enhanced degradation of organic dye under high alkaline conditions.

Designing of an effectual heterostructure photocatalyst for catalytic organic pollutant exclusion has been the subject of rigorous research intended to resolve the related environmental aggravation. Fabricating p-n junctions is an effective strategy to promote electron-hole separation of semiconductor photocatalysts as well as enhance the organic toxin degradation performance. In this study, a series of n-type NiAlFe-layered triple hydroxide (LTH) loaded with various ratios of p-type MoS2 was synthesized for forming a heterostructure LTH/MoS2 (LMs) by an in situ hydrothermal strategy. The photocatalysts were characterized by XRD, SEM&EDX, TEM, FT-IR, XPS, as well as UV-vis DRS. The photoactivity of photocatalysts was tested by the degradation of Indigo Carmine (IC) dye. The optimized catalyst (LM1) degrades 100% of indigo dye in high alkaline pH under UV light for 100 min. Besides, the degradation rate of LM1 is 15 times higher than that of pristine NiAlFe-LTH. The enhanced photoactivity is attributed to the synergistic effect between NiAlFe-LTH and MoS2 as well as the p-n junction formation.

Convenient preparation of indigo from the Ieaves of Baphicacanthus cusia(Nees) Bremek by enzymatic method and its MALDI-TOF-MS and UPLC-Q-TOF/MS analysis.

The manufacturing of indigo naturalis requires prolonged leaf soaking and lime stirring; the resulting indigo purity is less than 3.00% and the yield of indigo (measured in stems and leaves weight) is less than 0.50%, making it unsuitable for use in industrial procedures like printing and dyeing. An enzymatic method of creating indigo without the requirement for lime was investigated in order to generate high purity indigo. Single factor tests were performed to optimize the enzymatic preparation conditions. The findings showed that 60 °C, pH 5.5, 200 mL of leaves extract containing 0.45 mg/mL indican, and a 4:1 ratio of the acidic cellulose (activity: 9000 U/mL, liquid) to indican were the ideal parameters for enzymatic preparation. The yield of indigo was 40.32%, and the contents of indigo and indirubin were 37.37% and 2.30%, respectively. MALDI-TOF-MS in positive ion mode and UPLC-Q-TOF-MS in both positive and negative ion modes were used to analyze indigo extracts from Baphicacanthus cusia(Nees) Bremek by enzymatic preparation. It has been discovered that 13 alkaloids, 5 organic acids, 3 terpenoids, 3 steroids, 2 flavones, and 7 other compounds are present in indigo extracts. The presence of the indigo, indirubin, isorhamnetin, tryptanthrin, indigodole B, and indigodole C determined by UPLC-Q-TOF-MS was verified by MALDI-TOF-MS analysis. The enzymatic preparation of indigo extracts kept the same chemical makeup as conventional indigo naturalis. Thermal analysis and SEM morphology were used to confirm that there was no lime in the indigo extract. During the enzymatic process, Baphicacanthus cusia (Nees) Bremek was employed more effectively, increasing the yield and purity of indigo.

Efficient bioremediation of indigo-dye contaminated textile wastewater using native microorganisms and combined bioaugmentation-biostimulation techniques.

In this work, the bioremediation of wastewater from the textile industry with indigo dye content was carried out using combined bioaugmentation, bioventilation, and biostimulation techniques. Initially, the inoculum was prepared by isolating the microorganisms from the textile wastewater in a 2 L bioreactor. Then, the respirometry technique was implemented to determine the affinity of the microorganisms and the substrate by measuring CO2 and allowed the formulation of an empirical mathematical model for the growth kinetics of the microorganism. Finally, the bioremediation was carried out in a 3 L bioreactor obtaining an indigo dye removal efficiency of 20.7 ± 1.2%, 24.0 ± 1.5%, and 29.7 ± 1.1% for equivalent wavelengths of 436 nm, 525 nm, and 620 nm. The chemical oxygen demand showed an average reduction of 88.9 ± 2.5%, going from 470.7 ± 15.6 to 52.3 ± 10.7 ppm after 30 days under constant agitation and aeration. A negative generalized exponential model was fitted to assess the affinity of the microorganism with the wastewater as a substrate by evaluating the production of CO2 during the bioremediation. Bioremediation techniques improve water discharge parameters compared to chemical treatments implemented in the industry, reducing the use of substances that can generate secondary pollution. Bioaugmentation, biostimulation, and bioventing of the textile wastewater in this study demonstrate the potential of these combined techniques to serve as an efficient alternative for indigo-contaminated wastewater in the textile industry.

Clinical outcomes of patients with remitting ulcerative colitis after discontinuation of indigo naturalis.

Indigo naturalis is an effective treatment for ulcerative colitis. However, long-term use of indigo naturalis causes adverse events, such as pulmonary hypertension. The natural history of patients with ulcerative colitis who discontinued indigo naturalis after induction therapy is unknown. Moreover, the clinical features of patients who relapsed within 52 weeks after the discontinuation of indigo naturalis are unclear. This study aimed to assess the clinical outcomes of patients with ulcerative colitis after discontinuation of indigo naturalis and to identify potential markers responsible for relapse. This single-center retrospective study investigated the follow-up of 72 patients who achieved a clinical response 8 weeks after indigo naturalis treatment. We observed relapse in patients with ulcerative colitis after the discontinuation of indigo naturalis. We analyzed the factors predicting long-term outcomes after discontinuation of indigo naturalis. Relapse was observed in 24%, 57%, and 71% of patients at 8, 26, and 52 weeks, respectively. There were no predictive markers in patients who relapsed within 52 weeks after the discontinuation of indigo naturalis. The ulcerative colitis relapse rate after indigo naturalis discontinuation was high. Follow-up treatment is required after the discontinuation of indigo naturalis in patients with ulcerative colitis.

The double-edged sword effect of indigo naturalis.

Indigo naturalis (IN) is a dried powder derived from plants such as Baphicacanthus cusia (Neeks) Bremek., Polygonum tinctorium Ait. and Isatis indigotica Fork. It has a historical application as a dye in ancient India, Egypt, Africa and China. Over time, it has been introduced to China and Japan for treatment of various ailments including hemoptysis, epistaxis, chest discomfort, and aphtha. Clinical and pre-clinical studies have widely demonstrated its promising effects on autoimmune diseases like psoriasis and Ulcerative colitis (UC). Despite the documented efficacy of IN in UC patients, concerns have been raised on the development of adverse effects with long term consumption, prompting a closer examination of its safety and tolerability in these contexts. This review aims to comprehensively assess the efficacy of IN in both clinical and pre-clinical settings, with a detailed exploration of the mechanisms of action involved. Additionally, it summarizes the observed potential toxicity of IN in animal and human settings was summarized. This review will deepen our understanding on the beneficial and detrimental effects of IN in UC, providing valuable insights for its future application in patients with this condition.

pH-dependent and whole-cell catalytic decolorization of dyes using recombinant dye-decolorizing peroxidase from Rhodococcus jostii.

Dyes in wastewater have adverse effects on the environment and human health. Dye-decolorizing peroxidase (DyP) is a promising biocatalyst to dyes degradation, but the decolorization rates varied greatly which influencing factors and mechanisms remain to be fully disclosed. To explore an effective decolorizing approach, we have studied a DyP from Rhodococcus jostii (RhDyPB) which was overexpressed in Escherichia coli to decolorize four kinds of dyes, Reactive blue 19, Eosin Y, Indigo carmine, and Malachite green. We found the decolorization rates of the dyes by purified RhDyPB were all pH-dependent and the highest one was 94.4% of Malachite green at pH 6.0. ESI-MS analysis of intermediates in the decolorization process of Reactive blue 19 proved the degradation was due to peroxidase catalysis. Molecular docking predicated the interaction of RhDyPB with dyes, and a radical transfer reaction. In addition, we performed decolorization of dyes with whole E. coli cell with and without expressing RhDyPB. It was found that decolorization of dyes by E. coli cell was due to both cell absorption and degradation, and RhDyPB expression improved the degradation rates towards Reactive blue 19, Indigo carmine and Malachite green. The effective decolorization of Malachite green and the successful application of whole DyP-overexpressed cells in dye decolorization is conducive to the bioremediation of dye-containing wastewaters by DyPs.

Use of the Indigo CAT RX aspiration system during percutaneous coronary intervention.

BACKGROUND: The use of the Indigo CAT RX Aspiration System (Penumbra Inc.) during percutaneous coronary intervention has received limited study. METHODS: We retrospectively examined the clinical, angiographic, and procedural characteristics, outcomes, and follow-up of patients who underwent mechanical aspiration thrombectomy with the Indigo CAT RX system (Penumbra Inc.) at a large tertiary care hospital between January 2019 and April 2023. RESULTS: During the study period, 83 patients (85 lesions) underwent thrombectomy with the Indigo CAT RX. Mean patient age was 64.9 ± 14.48 years and 31.2% were women. The most common presentations were ST-segment elevation myocardial infarction (MI) (66.2%) and non-ST-segment elevation MI (26.5%). A final thrombolysis in MI flow grade of 3 and final myocardial blush grade of 3 were achieved in 76% and 46% of the cases, respectively. Technical success was achieved in 88.9% of the cases that included Indigo CAT RX treatment only, compared with 57.1% of the cases that also included manual aspiration. There were no device-related serious adverse events. At 30-day postprocedure, the incidence of major adverse cardiac events (composite of cardiovascular death, recurrent MI, cardiogenic shock, new or worsening New York Heart Association Class IV heart failure, stroke) was 8.5%: 1.3% stroke (postprocedure, in-hospital), 1.3% MI, 6.1% cardiac death, and 7.5% developed cardiogenic shock. CONCLUSIONS: Use of the Indigo CAT RX system is associated with high technical success and acceptable risk of complications, including stroke.

Chemoenzymatic indican for light-driven denim dyeing.

Blue denim, a billion-dollar industry, is currently dyed with indigo in an unsustainable process requiring harsh reducing and alkaline chemicals. Forming indigo directly in the yarn through indican (indoxyl-ß-glucoside) is a promising alternative route with mild conditions. Indican eliminates the requirement for reducing agent while still ending as indigo, the only known molecule yielding the unique hue of blue denim. However, a bulk source of indican is missing. Here, we employ enzyme and process engineering guided by techno-economic analyses to develop an economically viable drop-in indican synthesis technology. Rational engineering of PtUGT1, a glycosyltransferase from the indigo plant, alleviated the severe substrate inactivation observed with the wildtype enzyme at the titers needed for bulk production. We further describe a mild, light-driven dyeing process. Finally, we conduct techno-economic, social sustainability, and comparative life-cycle assessments. These indicate that the presented technologies have the potential to significantly reduce environmental impacts from blue denim dyeing with only a modest cost increase.

Effective Decolorization and Detoxification of Single and Mixed Dyes with Crude Laccase Preparation from a White-Rot Fungus Strain Pleurotus eryngii.

To fully harness the potential of laccase in the efficient decolorization and detoxification of single and mixed dyes with diverse chemical structures, we carried out a systematic study on the decolorization and detoxification of single and mixed dyes using a crude laccase preparation obtained from a white-rot fungus strain, Pleurotus eryngii. The crude laccase preparation showed efficient decolorization of azo, anthraquinone, triphenylmethane, and indigo dyes, and the reaction rate constants followed the order Remazol Brilliant Blue R > Bromophenol blue > Indigo carmine > New Coccine > Reactive Blue 4 > Reactive Black 5 > Acid Orange 7 > Methyl green. This laccase preparation exhibited notable tolerance to SO42- salts such as MnSO4, MgSO4, ZnSO4, Na2SO4, K2SO4, and CdSO4 during the decolorization of various types of dyes, but was significantly inhibited by Cl- salts. Additionally, this laccase preparation demonstrated strong tolerance to some organic solvents such as glycerol, ethylene glycol, propanediol, and butanediol. The crude laccase preparation demonstrated the efficient decolorization of dye mixtures, including azo + azo, azo + anthraquinone, azo + triphenylmethane, anthraquinone + indigo, anthraquinone + triphenylmethane, and indigo + triphenylmethane dyes. The decolorization kinetics of mixed dyes provided preliminary insight into the interactions between dyes in the decolorization process of mixed dyes, and the underlying reasons and mechanisms were discussed. Importantly, the crude laccase from Pleurotus eryngii showed efficient repeated-batch decolorization of single-, two-, and four-dye mixtures. This crude laccase demonstrated high stability and reusability in repeated-batch decolorization. Furthermore, this crude laccase was efficient in the detoxification of different types of single dyes and mixed dyes containing different types of dyes, and the phytotoxicity of decolorized dyes (single and mixed dyes) was significantly reduced. The crude laccase efficiently eliminated phytotoxicity associated with single and mixed dyes. Consequently, the crude laccase from Pleurotus eryngii offers significant potential for practical applications in the efficient decolorization and management of single and mixed dye pollutants with different chemical structures.

What Happens to a Pyrrole Hemithioindigo Photoswitch Trapped in a Fluorescent Protein?

Artificial molecular photoswitches that can be reversibly controlled into different configurations by external light stimulation have broad application prospects in various fields, such as materials and chemical biology. Among them, the pyrrole hemithioindigo (PHT) photoswitch has a geometric structure similar to that of the fluorescent protein chromophore. What happens when the chromophore is replaced by PHT, and does it achieve similar functions to the original one? To answer these questions, we carried out ONIOM(QM/MM) and classical molecular dynamics studies on the photoisomerization mechanism and spectroscopic properties of PHT in the fluorescent protein. The results showed that in the protein environment, the fate of excited PHT is governed by the competition between fluorescence emission and hula-twist isomerization. Due to the strong steric hindrance effects caused by the interlacing residues in the protein that restrict the PHT conformation transformation, the cis-to-trans isomerization process of PHT needs to overcome a barrier of at least 4.9 kcal/mol; thus, fluorescence emission is more dominant in competition. It is also found that the intermolecular interaction between LYS67 and the carbonyl oxygen of PHT has a significant effect on the fluorescence emission. These results revealed the photochemical reaction mechanism of a light-driven molecular switch in the fluorescent protein and provided further theoretical support for the field of chemical biology.

Indigo production goes green: a review on opportunities and challenges of fermentative production.

Indigo is a widely used dye in various industries, such as textile, cosmetics, and food. However, traditional methods of indigo extraction and processing are associated with environmental and economic challenges. Fermentative production of indigo using microbial strains has emerged as a promising alternative that offers sustainability and cost-effectiveness. This review article provides a critical overview of microbial diversity, metabolic pathways, fermentation strategies, and genetic engineering approaches for fermentative indigo production. The advantages and limitations of different indigo production systems and a critique of the current understanding of indigo biosynthesis are discussed. Finally, the potential application of indigo in other sectors is also discussed. Overall, fermentative production of indigo offers a sustainable and bio-based alternative to synthetic methods and has the potential to contribute to the development of sustainable and circular biomanufacturing.

Tryptophan-Based Hyperproduction of Bioindigo by Combinatorial Overexpression of Two Different Tryptophan Transporters.

Indigo is a valuable, natural blue dye that has been used for centuries in the textile industry. The large-scale commercial production of indigo relies on its extraction from plants and chemical synthesis. Studies are being conducted to develop methods for environment-friendly and sustainable production of indigo using genetically engineered microbes. Here, to enhance the yield of bioindigo from an E. coli whole-cell system containing tryptophanase (TnaA) and flavin-containing monooxygenase (FMO), we evaluated tryptophan transporters to improve the transport of aromatic compounds, such as indole and tryptophan, which are not easily soluble and passable through cell walls. Among the three transporters, Mtr, AroP, and TnaB, AroP enhanced indigo production the most. The combination of each transporter with AroP was also evaluated, and the combination of AroP and TnaB showed the best performance compared to the single transporters and two transporters. Bioindigo production was then optimized by examining the culture medium, temperature, isopropyl ß-D-1-thiogalactopyranoside concentration, shaking speed (rpm), and pH. The novel strain containing aroP and tnaB plasmid with tnaA and FMO produced 8.77 mM (2.3 g/l) of bioindigo after 66 h of culture. The produced bioindigo was further recovered using a simple method and used as a watercolor dye, showing good mixing with other colors and color retention for a relatively long time. This study presents an effective strategy for enhancing indigo production using a combination of transporters.

Indirubin mediates adverse intestinal reactions in guinea pigs by downregulating the expression of AchE through AhR.

Indirubin is the main component of the traditional Chinese medicine Indigo naturalis (IN), a potent agonist of aryl hydrocarbon receptors (AhRs). In China, IN is used to treat psoriasis and ulcerative colitis, and indirubin is used for the treatment of chronic myelogenous leukaemia. However, IN and indirubin have adverse reactions, such as abdominal pain, diarrhoea, and intussusception, and their specific mechanism is unclear.The purpose of our research was to determine the specific mechanism underlying the adverse effects of IN and indirubin. By tracking the modifications in guinea pigs after the intragastric administration of indirubin for 28 days.The results demonstrate that indirubin could accelerate bowel movements and decrease intestinal acetylcholinesterase (AchE) expression. Experiments with NCM460 cells revealed that indirubin significantly reduced the expression of AchE, and the AchE levels were increased after the silencing of AhR and re-exposure to indirubin.This study showed that the inhibition of AchE expression by indirubin plays a key role in the occurrence of adverse reactions to indirubin and that the underlying mechanism is related to AhR-mediated AchE downregulation.

Interaction of food colorant indigo carmine with human and bovine serum albumins: A multispectroscopic, calorimetric, and theoretical investigation.

In this work we have studied the interaction of the food dye Indigo-Carmine (IndC) with the most studied model transport proteins i.e. human and bovine serum albumin (HSA & BSA). A multispectroscopic approach was used to analyze the details of the binding process. The intrinsic fluorescence of both the albumins was significantly quenched by IndC and the quenching was both static and dynamic in nature with the former being dominant. The HSA-lndC and BSA-IndC distance after complexation was determined by Förster resonance energy transfer (FRET) method which suggested efficient energy transfer from the albumins to IndC. Thermodynamics of serum protein-IndC complexation was estimated by isothermal titration calorimetry (ITC) which revealed that the binding was enthalpy driven. Circular dichroism (CD) and FTIR spectroscopy revealed that the binding of IndC induced secondary structural changes in both the serum proteins. Synchronous and 3D fluorescence spectroscopy revealed that the binding interaction caused microenvironmental changes of protein fluorophores. Molecular docking analysis suggested that hydrogen bonding and hydrophobic interactions are the major forces involved in the complexation process.

Diagnostic performance of deep-learning-based virtual chromoendoscopy in gastric neoplasms.

BACKGROUNDS: Cycle-consistent generative adversarial network (CycleGAN) is a deep neural network model that performs image-to-image translations. We generated virtual indigo carmine (IC) chromoendoscopy images of gastric neoplasms using CycleGAN and compared their diagnostic performance with that of white light endoscopy (WLE). METHODS: WLE and IC images of 176 patients with gastric neoplasms who underwent endoscopic resection were obtained. We used 1,633 images (911 WLE and 722 IC) of 146 cases in the training dataset to develop virtual IC images using CycleGAN. The remaining 30 WLE images were translated into 30 virtual IC images using the trained CycleGAN and used for validation. The lesion borders were evaluated by 118 endoscopists from 22 institutions using the 60 paired virtual IC and WLE images. The lesion area concordance rate and successful whole-lesion diagnosis were compared. RESULTS: The lesion area concordance rate based on the pathological diagnosis in virtual IC was lower than in WLE (44.1% vs. 48.5%, p < 0.01). The successful whole-lesion diagnosis was higher in the virtual IC than in WLE images; however, the difference was insignificant (28.2% vs. 26.4%, p = 0.11). Conversely, subgroup analyses revealed a significantly higher diagnosis in virtual IC than in WLE for depressed morphology (41.9% vs. 36.9%, p = 0.02), differentiated histology (27.6% vs. 24.8%, p = 0.02), smaller lesion size (42.3% vs. 38.3%, p = 0.01), and assessed by expert endoscopists (27.3% vs. 23.6%, p = 0.03). CONCLUSIONS: The diagnostic ability of virtual IC was higher for some lesions, but not completely superior to that of WLE. Adjustments are required to improve the imaging system's performance.

A Randomized Clinical Trial Evaluating Indigo Carmine as a Visualization Aid for Evaluating Ureteral Patency.

OBJECTIVE: To determine whether intravenous indigo carmine provides a visualization advantage compared to saline in the evaluation of ureteral patency in a randomized, controlled clinical trial. METHODS: Patients undergoing urological or gynecological surgical procedures in which the patency of the ureter was to be assessed received a saline injection and were randomized to receive 2.5 mL or 5.0 mL of indigo carmine. Blinded video assessments were conducted by independent reviewers using a conspicuity scale ranked 1 (poorest) to 5 (best), and subjects with scores ≥3 and at least a + 1-point difference from saline were considered responders. Time to visualization was recorded for indigo carmine. A responder analysis evaluated whether indigo carmine showed improved visualization. RESULTS: There were 96 ureters evaluated with the 5.0 mL dose of indigo carmine, 92 with the 2.5 mL dose, and 180 with saline. Most ureters were scored a 4 or higher on the conspicuity scale following indigo carmine; both doses were significantly better than saline (P < .0001). Overall, 92.3% of patients were rated as a responder for either ureter. The median time to visualization of blue color was not significantly different (6.0 minutes in the 5.0 mL group and 5.9 minutes in the 2.5 mL group). There were no adverse events related to indigo carmine use. CONCLUSION: Both dose levels of indigo carmine were significantly better than saline as a visualization aid for ureter patency.

Artificial intelligence-aided diagnostic imaging: A state-of-the-art technique in precancerous screening.

BACKGROUND AND AIM: Chromoendoscopy with the use of indigo carmine (IC) dye is a crucial endoscopic technique to identify gastrointestinal neoplasms. However, its performance is limited by the endoscopist's skill, and no standards are available for lesion identification. Thus, we developed an artificial intelligence (AI) model to replace chromoendoscopy. METHODS: This pilot study assessed the feasibility of our novel AI model in the conversion of white-light images (WLI) into virtual IC-dyed images based on a generative adversarial network. The predictions of our AI model were evaluated against the assessments of five endoscopic experts who were blinded to the purpose of this study with a staining quality rating from 1 (unacceptable) to 4 (excellent). RESULTS: The AI model successfully transformed the WLI of polyps with different morphologies and different types of lesions in the gastrointestinal tract into virtual IC-dyed images. The quality ratings of the real IC-dyed and AI images did not significantly differ concerning surface structure (AI vs IC: 3.08 vs 3.00), lesion border (3.04 vs 2.98), and overall contrast (3.14 vs 3.02) from 10 sets of images (10 AI images and 10 real IC-dyed images). Although the score depended significantly on the evaluator, the staining methods (AI or real IC) and evaluators had no significant interaction (P > 0.05) with each other. CONCLUSION: Our results demonstrated the feasibility of employing AI model's virtual IC staining, increasing the possibility of being employed in daily practice. This novel technology may facilitate gastrointestinal lesion identification in the future.