Photodynamic Therapy of Novel Photosensitizer Ameliorates TNBS-Induced Ulcerative Colitis via Inhibition of AOC1

Inhibition of the STAT3-EPHX2 axis promotes regression of ulcerative colitis by treatment with novel porphyrin derivative

LD4, a novel porphyrin derivative, has attracted much attention for its excellent anti-inflammatory properties. It can promote the healing of colonic mucosa, reduce inflammatory response, regulate oxidative stress, and thus improve ulcerative colitis (UC) symptoms. However, the specific signaling pathways of LD4-PDT involved in UC have not been explored. The present study aimed to elucidate the effects of LD4 on UC and to investigate the underlying mechanisms both in vivo and in vitro. We classified and screened the LD4-PDT proteomic data to obtain key targets. Proteomic data revealed that EPHX2 and STAT3 are key targets of LD4-PDT for UC. Moreover, transcription factor STAT3 positively regulates the expression of EPHX2. Inhibiting EPHX2 can prevent the activation of NF-κB signaling pathway. Next, through pharmacological inhibition experiments, we confirmed that LD4-PDT can reduce intestinal inflammation by inhibiting STAT3-EPHX2 axis. However, by treating normal intestinal epithelial cells and colon cancer cells with TPPU and Stattic, our data confirmed that the STAT3-EPHX2 axis does not exist in colon cancer. In this study, we demonstrated that the transcription factor STAT3 can positively regulate the expression of EPHX2 in normal colon. LD4 can alleviate UC by inhibiting the STAT3-EPHX2 axis, but this axis does not exist in colon cancer. LD4-PDT may become a new and effective method for treating UC.

Exploring the efficacy of photodynamic antimicrobial chemotherapy on diabetic foot ulcers in rats

We investigate the efficacy of photodynamic antimicrobial chemotherapy (PACT) and its combination with an antibiotic in the treatment of diabetic foot ulcers (DFUs) in rats using a novel cationic amino acid porphyrin-based photosensitizer. The research findings demonstrate that the combination of novel cationic photosensitizer-mediated PACT and an antibiotic exhibits significant therapeutic efficacy in treating deep ulcers in a rat model of DFUs. Moreover, the PACT + Antibiotic group displays enhanced angiogenesis, improved tissue maturation, and superior wound healing effect. Micro-computed tomography examination showed that the periosteal reaction was most obvious in the PACT + Antibiotic group. The cortical bone volume ratio (BV/TV), the bone mineral density, and trabecular thickness were significantly higher in the PACT + Antibiotic group than in the model group (p < 0.05). The combination of PACT and antibiotic plays a sensitizing therapeutic role, which provides a new idea for the clinical treatment of DFUs.

Sulfated Polysaccharides from Sea Cucumber Cooking Liquid Prevents Obesity by Modulating Gut Microbiome, Transcriptome, and Metabolite Profiles in Mice Fed a High-Fat Diet

We aimed to explore the anti-obesity mechanism from the microbiome, metabolome, and transcriptome viewpoints, focusing on the sulfated polysaccharides found in the cooking liquid of Apostichopus japonicus (CLSPAJ) to explore the potential mediators of the anti-obesity effects in mice fed a high-fat diet (HFD). The mice treated with CLSPAJ showed a decrease in obesity and blood lipid levels. Gut microbiome dysbiosis caused by the HFD was reversed after CLSPAJ supplementation, along with increased levels of indole-3-ethanol, N-2-succinyl-L-glutamic acid 5-semialdehyde, and urocanic acid. These increases were positively related to the increased Akkermansia, Lactobacillus, Roseburia, and Phascolarctobacterium. Transcriptome analysis showed that B cell receptor signaling and cytochrome P450 xenobiotic metabolism were the main contributors to the improvement in obesity. Metabolome-transcriptome analysis revealed that CLSPAJ reversal of obesity was mainly due to amino acid metabolism. These findings suggest that CLSPAJ could be a valuable prebiotic preparation for preventing obesity-related diseases.

Photodynamic Therapy for Inflammatory and Cancerous Diseases of the Intestines: Molecular Mechanisms and Prospects for Application

Photodynamic therapy (PDT) is a minimally invasive treatment that effectively targets cancer and inflammatory diseases. It has gained recognition for its efficacy, low toxicity, and potential for repeated use. Colorectal cancer (CRC) and inflammatory bowel diseases (IBD), including Crohn's disease (CD), and ulcerative colitis (UC), impose a significant burden on global intestinal health, with increasing incidence and prevalence rates. PDT shows promise as an emerging approach for gastrointestinal disease treatment, particularly IBD and CRC. Extensive preclinical research has demonstrated the safety and effectiveness of PDT for IBD and CRC, while clinical studies are currently underway. This review provides an overview of the underlying mechanisms responsible for the anti-inflammatory and anti-tumor effects of PDT, offering insights into the clinical application of PDT in IBD and CRC treatment. It is expected that this review will serve as a valuable reference for future research on PDT for CRC and IBD, contributing to advancements in the treatment of inflammatory and cancerous diseases of the intestines.

Synthesis and photodynamic antimicrobial chemotherapy against multi-drug resistant Proteus mirabilis of ornithine-porphyrin conjugates in vitro and in vivo

For the treatment of bacterial infections, photodynamic antimicrobial chemotherapy (PACT) has the advantage of circumventing multi-drug resistance. In this work, new cationic photosensitizers against multi-drug resistant Proteus mirabilis (MRPM) were designed and synthesized by the conjugation of amino phenyl porphyrin with basic amino acid L-ornithine. Their photoinactivation efficacies against MRPM in vitro were reported and include the influence of laser energy, uptake, MIC and MBC, dose-dependent photoinactivation effects, membrane integrity, and fluorescence imaging. The PACT in vivo was evaluated using a wound mouse model infected by MRPM. Photosensitizer 4d displayed high photo inactivation efficacy against MRPM at 7.81 μM under illumination, and it could accelerate wound healing via bactericidal effect. These ornithine-porphyrin conjugates are potential photosensitizers for PACT in the treatment of MRPM infection.

Evaluation of anti-inflammatory effects of leaf and seed extracts of Plantago major on acetic acid-induced ulcerative colitis in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Plantago major (P. major) has traditionally been used in Iranian Persian medicine to treat gastrointestinal ulcers and bleeding.

RESEARCH OBJECTIVES

This study aimed to investigate the anti-inflammatory effects of the leaf and seed extracts of P. major in rats with acetic acid-induced ulcerative colitis (UC).

MATERIALS AND METHODS

To this end, 49 rats were randomly divided into seven groups. UC was induced in all groups but the control (vehicle) group using a single intra-rectal administration of 2 ml of 4% acetic acid. Other groups received daily intraperitoneal (i.p.) injections of the seed extract of P. major (400 mg/kg and 700 mg/kg), the leaf extract of P. major (400 mg/kg and 700 mg/kg), and sulfasalazine (400 mg/kg) for seven consecutive days, respectively. The rats' rectum was surgically removed and evaluated for macroscopic and microscopic damage. The tissue levels of oxidative stress and inflammatory markers were measured using the ELISA method.

RESULTS

The high-dose leaf extract significantly decreased ulcer index and histopathologic damage as well as the tissue levels of IL-6, TNF-α, PGE2, IL-1β, MPO, and MDA compared to the damage group. The low-dose leaf extract also significantly reduced the levels of some markers. The seed extract in the two used doses caused a modest decrease in the histopathological damages and ulcer index.

CONCLUSIONS

P. major leaf extract effectively reduces inflammation and mucosal damage in rats with UC, especially when administered in high doses. P. major seed extract has minimal protective effects on UC.

Extracellular vesicles as a novel photosensitive drug delivery system for enhanced photodynamic therapy

Photodynamic therapy (PDT) is a promising non-invasive therapeutic approach that utilizes photosensitizers (PSs) to generate highly reactive oxygen species (ROS), including singlet oxygen, for removal of targeted cells. PDT has been proven efficacious for the treatment of several diseases, including cancer, cardiovascular disease, inflammatory bowel disease, and diabetic ocular disease. However, the therapeutic efficacy of PDT is limited and often accompanied by side effects, largely due to non-specific delivery of PSs beyond the desired lesion site. Over the past decade, despite various nanoparticular drug delivery systems developed have markedly improved the treatment efficacy while reducing the off-target effects of PSs, concerns over the safety and toxicity of synthetic nanomaterials following intravenous administration are raised. Extracellular vesicles (EVs), a type of nanoparticle released from cells, are emerging as a natural drug delivery system for PSs in light of EV's potentially low immunogenicity and biocompatibility compared with other nanoparticles. This review aims to provide an overview of the research progress in PS delivery systems and propose EVs as an alternative PS delivery system for PDT. Moreover, the challenges and future perspectives of EVs for PS delivery are discussed.

PPARGC1A affects inflammatory responses in photodynamic therapy (PDT)-treated inflammatory bowel disease (IBD)

BACKGROUND

Chronic inflammation of the gastrointestinal tract is a feature of inflammatory bowel disease (IBD), including Crohn's disease (CD) and ulcerative colitis (UC). Targeting inflammatory signaling represents promising strategy for IBD treatment regimens.

METHODS

Dextran sulfate sodium (DSS)-induced colitis model was established in mice. Histopathological examinations were conducted by H&E staining and IHC staining. IL-1β, IL-10, and TNF-α were tested by ELISA kits. TargetScan was used to predict miRNAs that target PPARGC1A and luciferase activity assay was performed to validate the predicted binding.

RESULTS

DSS-induced acute colitis model was successfully established in mice; photodynamic therapy (PDT) treatment partially improved DSS-induced colonic damages and cell inflammation. Microarray assays and integrative bioinformatics analysis identified PPARG coactivator 1 alpha (PPARGC1A) as a significantly differentially-expressed gene in PDT-treated IBD compared with non-treated IBD. PPARGC1A expression was downregulated in IBD clinical samples, DSS-induced colitis mice colons, and DSS-stimulated colonic epithelial cells, whereas partially upregulated by PDT treatment in DSS-stimulated cells. Single DSS stimulation significantly promoted cellular inflammation; PDT partially attenuated, whereas sh-PPARGC1A transduction further enhanced DSS effects on cancer cell inflammation. In colitis mice, DSS decreased PPRA-α and PPRA-γ proteins in mice colons; the in vivo effects of DSS were partially attenuated by PDT treatment, whereas amplified by sh-PPARGC1A transduction. Upstream miR-301a-3p targeted and inhibited PPARGC1A expression.

CONCLUSIONS

Collectively, PPARGC1A, which is downregulated in DSS-induced acute colitis and DSS-stimulated colonic epithelial cells, could be upregulated by PDT treatment. PPARGC1A knockdown could attenuate PDT therapeutic effects on DSS-induced acute colitis and DSS-stimulated colonic epithelial cells.