Qing Dai, a traditional Chinese medicine for the treatment of chronic hemorrhagic radiation proctitis

Prospective feasibility study of indigo naturalis ointment for chemotherapy-induced oral mucositis

OBJECTIVES

Indigo naturalis, a herbal medicine effective against ulcerative colitis, exhibits anti-inflammatory effects and induces interleukin-22-mediated antimicrobial peptide production. Anti-inflammatory activity and the prevention of secondary infection are essential for the management of chemotherapy-induced oral mucositis (CIOM); therefore, we developed an indigo naturalis ointment to be administered topically for CIOM and evaluated its feasibility.

METHODS

We performed a single-centre, open-label, prospective feasibility study from March 2017 to December 2018. The key eligibility criteria for the subjects were as follows: (1) receiving chemotherapy for a malignant tumour; (2) grade 1 or 2 CIOM and (3) receiving continuous oral care. The treatment protocol comprised topical indigo naturalis ointment application three times a day for 7 days. The primary endpoint assessed was feasibility. The secondary endpoints assessed were the changes in oral findings, oral cavity pain and safety.

RESULTS

Nineteen patients with CIOM were enrolled. The average feasibility (the proportion of prescribed applications that were carried out) observed in this study was 94.7%±8.9% (95% CI 90.5% to 99.0%), which was higher than the expected feasibility. The revised oral assessment guide scores of the mucous membrane domain and total scores were significantly improved. All patients reported a reduction in oral cavity pain, with a median pain resolution duration of 6 days. No serious adverse events were observed.

CONCLUSIONS

The indigo naturalis ointment was feasible, and showed the potential for efficacy and safety. Larger randomised controlled trials are needed to further assess the efficacy and safety of indigo naturalis compared with a placebo.

TRIAL REGISTRATION NUMBER

UMIN000024271.

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.

Short-term and long-term outcomes of indigo naturalis treatment for inflammatory bowel disease

BACKGROUND AND AIM

Indigo naturalis (IN) is a traditional Chinese herbal medicine reported to be effective in inducing remission in ulcerative colitis (UC). We conducted a retrospective observational study to investigate the efficacy and safety of IN for induction and maintenance therapy in patients with inflammatory bowel disease.

METHODS

Data were collected from the electric medical records of patients with inflammatory bowel disease who had started IN treatment between March 2015 and April 2017 at Kyushu University Hospital. Clinical response and remission rates were assessed based on the clinical activity index determined by Rachmilewitz index or Crohn's disease (CD) activity index. Cumulative IN continuation rates were estimated using the Kaplan-Meier method. Overall adverse events (AEs) during follow-up were also analyzed.

RESULTS

Seventeen UC patients and eight CD patients were enrolled. Clinical response and remission rates at week 8 were 94.1% and 88.2% in UC patients and 37.5% and 25.0% in CD patients, respectively. Clinical remission rates, as assessed through non-responders imputation analyses at weeks 52 and 104, were 76.4% and 70.4% in UC patients and 25.0% and 25.0% in CD patients, respectively. Ten patients (40%) experienced AEs during follow-up. Three patients (12%) experienced severe AEs, including acute colitis requiring hospitalization in two patients and acute colitis with intussusception requiring surgery in one patient.

CONCLUSIONS

Indigo naturalis showed favorable therapeutic efficacy in UC, whereas its therapeutic efficacy in CD appeared to be modest. The risk of severe AEs should be recognized for IN treatment.

Indigo Naturalis Suppresses Colonic Oxidative Stress and Th1/Th17 Responses of DSS-Induced Colitis in Mice

Indigo naturalis (also known as Qing-dai, or QD), a traditional Chinese medicine, has been widely used as an anticolitis regimen in the clinical practice of Chinese medicine. However, the precise mechanisms behind its efficacy remain unknown. We investigated the protective effects and associated molecular mechanisms of QD in DSS-induced colitis in mice. We found that QD administration attenuated DSS-induced colon shortening, tissue damage, and the disease activity index during the onset of colitis. Moreover, QD administration significantly suppressed colonic MPO activity and increased the activities of colonic T-SOD, CAT, and GSH-Px, as well the expression of p-AMPK and Nrf-2 in colon tissues of colitic mice. In addition, QD was capable of reducing the colonic Th1 and Th17 cell cytokines, the frequencies of Th1 and Th17 cells, and the phosphorylation of p-STAT1 and p-STAT3 in the mesenteric lymph nodes of colitic mice. An in vitro assay showed that QD significantly suppressed the differentiation of Th1 and Th17 cells. These findings suggest that QD has the potential to alleviate experimental colitis by suppressing colonic oxidative stress and restraining colonic Th1/Th17 responses, which are associated with activating AMPK/Nrf-2 signals and inhibiting STAT1/STAT3 signals, respectively. These findings also support QD as an effective regimen in the treatment of IBD.

Efficacy of Indigo Naturalis Therapy for Ulcerative Colitis: A Case Series

Objective Indigo naturalis (IN) is a traditional Chinese medicine that has recently been reported to be effective for ulcerative colitis (UC). The aim of this study was to evaluate the efficacy and safety of IN. Methods We performed a retrospective observational study for 14 patients with UC treated with IN from October 2015 to December 2016. Results After 8 weeks of oral administration of IN, the partial Mayo score decreased from 4 (2-5) to 1.5 (0-4) [median, interquartile range (IQR), p=0.015]. Among 10 active UC patients, 5 (50%) showed a clinical response, and 4 (40%) achieved clinical remission. Serial changes of endoscopic activity were evaluated in nine patients using the Mayo endoscopic subscore (MES), Rachmilewitz endoscopic index (REI), and UC endoscopy index of severity (UCEIS). The MES decreased from 2 (2-3) to 1 (1-2) [median (IQR), p=0.005], the REI decreased from 7 (5.5-11) to 3 (1-7) [median (IQR), p=0.008], and the UCEIS decreased from 3 (3-4.5) to 1 (0.5-3.5) [median (IQR), p=0.039]. One patient developed acute right-sided colitis with wall thickening and edematous change, and the remaining 13 showed no adverse events. Conclusion We conclude that IN is effective for patients with UC as a therapy for inducing remission.

The preventive effect of Qing Dai on bisphosphonate-induced gastric cellular injuries

The Chinese herbal medicine Qing Dai has been traditionally used for the treatment of various inflammatory diseases. We previously reported that reactive oxygen species play an important role in bisphosphonate-induced gastrointestinal injuries and that Qing Dai improved ulcerative colitis by scavenging reactive oxygen species. In this study, we investigated whether Qing Dai prevented bisphosphonate-induced gastric cellular injuries. Risedronate (a bisphosphonate) was added to rat gastric mucosal cells. Risedronate-induced cellular injury, cellular lipid peroxidation, mitochondrial membrane potential, and reactive oxygen species production in rat gastric mucosal cells were examined via viable cell counting, specific fluorescent indicators, and electron spin resonance. Pretreatment with Qing Dai attenuated the fluorescence intensity of diphenyl-1-pyrenylphosphine and MitoSox as well as the signal intensities of electron spin resonance. Cell viability improved from 20% to 80% by pretreatment with Qing Dai. Thus, Qing Dai prevented this injury by suppressing mitochondrial reactive oxygen species production, which is the main cause of cellular lipid peroxidation. Qing Dai also maintained mitochondrial potential, reducing reactive oxygen species production. We conclude that Qing Dai has protective effects on bisphosphonate-induced gastrointestinal injury and thus has the potential for clinical application.

Acute pancreatitis associated with indigo naturalis in pediatric severe Crohn's disease

The incidence of inflammatory bowel disease (IBD) is rapidly increasing worldwide. Indigo naturalis is known to have an antiinflammatory effect. Indigo naturalis has been traditionally used in the treatment of IBD in China and Japan. Currently, it is used as a primary or adjunctive drug in patients with ulcerative colitis. There are some reports of the effects of indigo naturalis when used in patients with ulcerative colitis. However, its usage has been associated with adverse events, including liver dysfunction, headache, gastrointestinal disturbance, and pulmonary hypertension. Pancreatitis as an adverse event during treatment using indigo naturalis has not yet been reported. We report a case of recurrent events of pancreatitis that occurred briefly after starting medication with indigo naturalis in a child with severe Crohn’s disease. The pancreatitis improved after indigo naturalis was discontinued in 2 events. This is the first case to report the association between pancreatitis and indigo naturalis in the English literature.

Efficacy of Indigo Naturalis in a Multicenter Randomized Controlled Trial of Patients With Ulcerative Colitis

BACKGROUND & AIMS

Indigo naturalis (IN) is a traditional Chinese medicine that contains ligands for the aryl hydrocarbon receptor and promotes regeneration of the mucosa by inducing production of interleukin 22. IN might induce mucosal healing in patients with ulcerative colitis (UC). We performed a randomized controlled trial to investigate the safety and efficacy of IN in patients with UC.

METHODS

We performed a multicenter, double-blind trial evaluating the safety of 86 patients in Japan with active UC (Mayo scores of 6 or more), enrolled from March 30 through December 27, 2016. Patients were randomly assigned to groups and given a daily dose of 0.5, 1.0, or 2.0 g IN or placebo (1:1:1:1 ratio) for 8 weeks. The primary endpoint was the rate of clinical response at week 8, defined as a 3-point decrease in the Mayo score and a decrease of at least 30% from baseline, with a decrease of at least 1 point for the rectal bleeding subscore or absolute rectal bleeding score of 0-1. The main secondary endpoint was the rate of clinical remission at week 8, defined as a Mayo score or ≤2 and no subscores with a value >1. Mucosal healing was also assessed at week 8.

RESULTS

The trial was terminated because of an external reason: a report of pulmonary arterial hypertension in a patient who used self-purchased IN for 6 months. In the intent-to-treat analysis, we observed a significant, dose-dependent linear trend in proportions of patients with clinical responses (13.6% with a clinical response to placebo; 69.6% to 0.5 g IN; 75.0% to 1.0 g IN; and 81.0% to 2.0 g IN) (Cochran-Armitage trend test P < .0001 compared with placebo). Proportions of patients in clinical remission at week 8 were significantly higher in the 1.0 g IN group (55.0%, P = .0004) and the 2.0 g IN group (38.1%, (P = .0093) than in the placebo group (4.5%). Proportions of patients with mucosal healing were 13.6% in the placebo group, 56.5% in the 0.5 g IN group, 60.0% in the 1.0 g IN group, and 47.6% in the 2.0 g IN group (P = .0278 compared with placebo). Although mild liver dysfunction was observed in 10 patients who received IN, no serious adverse events were observed.

CONCLUSIONS

In a randomized, placebo-controlled trial, we found 8 weeks of IN (0.5-2.0 g per day) to be effective in inducing a clinical response in patients with UC. However, IN should not yet be used because of the potential for adverse effects, including pulmonary arterial hypertension. Clinical Trials Registry no: UMIN000021439 (http://www.umin.ac.jp/ctr/).

Indole compounds may be promising medicines for ulcerative colitis

Indole compounds are extracted from indigo plants and have been used as blue or purple dyes for hundreds of years. In traditional Chinese medicine, herbal agents in combination with Qing-Dai (also known as indigo naturalis) have been used to treat patients with ulcerative colitis (UC) and to remedy inflammatory conditions. Recent studies have noted that indole compounds can be biosynthesized from tryptophan metabolites produced by various enzymes derived from intestinal microbiota. In addition to their action on indole compounds, the intestinal microbiota produce various tryptophan metabolites that mediate critical functions through distinct pathways and enzymes. Furthermore, some indole compounds, such as indigo and indirubin, act as ligands for the aryl hydrocarbon receptor. This signaling pathway stimulates mucosal type 3 innate lymphoid cells to produce interleukin-22, which induces antimicrobial peptide and tight junction molecule production, suggesting a role for indole compounds during the mucosal healing process. Thus, indole compounds may represent a novel treatment strategy for UC patients. In this review, we describe the origin and function of this indole compound-containing Chinese herb, as well as the drug development of indole compounds.