Diindolylmethane Research Articles

3,3'-diindolylmethane exerts antiproliferation and apoptosis induction by TRAF2-p38 axis in gastric cancer.

3,3'-diindolylmethane (DIM), an active phytochemical derivative extracted from cruciferous vegetables, possesses anticancer effects. However, the underlying anticancer mechanism of DIM in gastric cancer remains unknown. Tumor necrosis factor (TNF) receptor-associated factor 2 (TRAF2), one of the signal transduction proteins, plays critical role in proliferation and apoptosis of human gastric cancer cells, but there are still lack of practical pharmacological modulators for potential clinical application. Here, we further explored the role of TRAF2 in inhibiting cell proliferation and inducing apoptosis by DIM in human gastric cancer BGC-823 and SGC-7901 cells. After treating BGC-823 and SGC-7901 cells with DIM for 24 h, cell proliferation, apoptosis and TRAF2-related protein were measured. Our findings showed that DIM inhibited the expressions of TRAF2, activated p-p38 and its downstream protein p-p53, which were paralleled with DIM-triggered cells proliferation, inhibition and apoptosis induction. These effects of DIM were reversed by TRAF2 overexpression or p38 mitogen-activated protein kinase (MAPK)-specific inhibitor (SB203580). Taken together, our data suggest that regulating TRAF2/p38 MAPK signaling pathway is essential for inhibiting gastric cancer proliferation and inducing apoptosis by DIM. These findings broaden the understanding of the pharmacological mechanism of DIM's action as a new modulator of TRAF2, and provide a new therapeutic target for human gastric cancer.

Modulation of the G-Protein-Coupled Receptor 84 (GPR84) by Agonists and Antagonists.

Since the discovery of medium-chain fatty acids as GPR84 ligands, significant advancements have been made in the development of GPR84 agonists and antagonists. Most agonists have lipid-like structures except for 3,3'-diindolylmethane (DIM), which acts as an allosteric agonist. GPR84 activation in macrophages leads to increased cytokine secretion, chemotaxis, and phagocytosis, revealing the proinflammatory role of GPR84 associated with various inflammatory responses. Three GPR84 antagonists (S)-2-((1,4-dioxan-2-yl)methoxy)-9-(cyclopropylethynyl)-6,7-dihydro-4H-pyrimido[6,1-a]isoquinolin-4-one (GLPG1205), sodium 2-(3-pentylphenyl)acetate (PBI-4050), and sodium 2-(3,5-dipentylphenyl)acetate (PBI-4547) have displayed therapeutic effects in animal models of several inflammatory and fibrotic diseases and are being evaluated in clinical studies. Although GLPG1205 has failed in a clinical trial for ulcerative colitis, it is undergoing another phase II clinical study for idiopathic pulmonary fibrosis. Further studies are needed to resolve the GPR84 structure, identify more endogenous ligands, elucidate their physiological and pathological roles, and fulfill the therapeutic potential of GPR84 antagonists and agonists.

PTEN/Akt Signaling-Mediated Activation of the Mitochondrial Pathway Contributes to the 3,3'-Diindolylmethane-Mediated Antitumor Effect in Malignant Melanoma Cells.

3,3'-diindolylmethane (DIM) has an anticancer activity, but the role DIM plays on malignant melanoma cells and its specific mechanism is unclear. We studied the biological effects of DIM on malignant melanoma cells and the related mechanism and the results showed that DIM significantly suppressed cell proliferation and induced apoptosis in malignant melanoma cells. In addition, the expression levels of phosphatase and tensin homolog deleted on chromosome ten (PTEN), Bax, Bid, cleaved caspase-3, and cleaved caspase-9 were increased after DIM treatment. In A2058 PTENmut cells, DIM-mediated inhibition of proliferation and DIM-induced apoptosis were attenuated. Additionally, the overexpression and knockdown of PTEN could regulate such effects of DIM in malignant melanoma cells. Furthermore, DIM exerted growth-inhibiting and apoptosis-inducing effects in vivo. This study demonstrated that DIM has antitumor effect in human malignant melanoma cells through the mitochondrial apoptotic pathway activated by PTEN/Akt signaling.

Anti-inflammatory activity of diindolylmethane alleviates Riemerella anatipestiferinfection in ducks.

3,3'-Diindolylmethane (DIM) is found in cruciferous vegetables and is used to treat various inflammatory diseases because of its potential anti-inflammatory effects. To investigate effects of DIM in Riemerella anatipestifer-infected ducks which induce upregulation of inflammatory cytokines, ducks were treated orally with DIM at dose of 200 mg/kg/day and infected the following day with R. anatipestifer. Infected and DIM-treated ducks exhibited 14% increased survival rate and significantly decreased bacterial burden compared to infected untreated ducks. Next, the effect on the expression level of inflammatory cytokines (interleukin [IL]-17A, IL-17F, IL-6, IL-1β) of both in vitro and in vivo DIM-treated groups was monitored by quantitative reverse-transcription PCR (qRT-PCR). Generally, the expression levels of the cytokines were significantly reduced in DIM-treated splenic lymphocytes stimulated with killed R. anatipestifer compared to stimulated untreated splenic lymphocytes. Similarly, the expression levels of the cytokines were significantly reduced in the spleens and livers of DIM-treated R. anatipestifer-infected ducks compared to infected untreated ducks. This study demonstrated the ameliorative effects of DIM in ducks infected with R. anatipestifer. Thus, DIM can potentially be used to prevent and/or treat R. anatipestifer infection via inhibition of inflammatory cytokine expression.

3,3'-Diindolylmethane Enhances Tumor Regression After Radiation Through Protecting Normal Cells to Modulate Antitumor Immunity

PurposePreclinical and clinical data indicate that radiation therapy acts as an immune modifier, having both immune-stimulatory and immunosuppressive effects on the tumor-immune microenvironment (TIME). 3.3’-diindolylmethane (DIM) sensitizes tumor cells to radiation and protects mice from lethal doses of total body irradiation. We hypothesize that protecting nontumoral cells from the adverse effects of radiation treatment (RT) may help to correct immunosuppression resulting from radiation. Methods and MaterialsWe generated tumor graft models using immune-competent and immune-deficient mouse strains. Narrow-beamed radiation was targeted to tumor sites using shielding. Tumor regression was monitored after DIM and RT versus RT alone. The effects of DIM on the efficacy of RT were assessed using immunohistochemistry staining and gene expression profiling. Complete blood counts, clonogenic cell survival assays, and global gene expression profiling of cultured cells were performed to study DIM’s radioprotective effects on normal cells. ResultsDIM enhanced tumor regression after RT in immune-competent but not immune-deficient mice. Data indicated that DIM increased intratumoral immune cells after RT, contributing to enhanced immunologic responses such as adhesion and antigen processing. DIM protected normal cells from radiation-induced immediate injuries in vitro and in vivo. Transcriptomic profiling of cultured cells showed that DIM treatment mildly increased expression of some genes that are normally induced after radiation, such as genes involved in cell cycle arrest and apoptosis. ConclusionsIn this study, using cultured cells and preclinical breast cancer models, we show that DIM protects normal cells from radiation-induced immediate cellular injury and combination treatment of DIM and radiation potentiates antitumor immune responses and enhances the efficacy of RT.

Breast cancer organoid model allowed to reveal potentially beneficial combinations of 3,3′-diindolylmethane and chemotherapy drugs

Epigenetic alterations represent promising therapeutic targets in cancer treatment. Recently it was revealed that small molecules have the potential to act as microRNA silencers. Capacity to bind the discrete stem-looped structure of pre-miR-21 and prevent its maturation opens opportunities to utilize such compounds for the prevention of initiation, progression, and chemoresistance of cancer. Molecular simulations performed earlier identified 3,3′-diindolylmethane (DIM) as a potent microRNA-21 antagonist. However, data on DIM and microRNA-21 interplay is controversial, which may be caused by the limitations of the cell lines.

DIM mitigates the development of experimental autoimmune encephalomyelitis by maintaining the stability and suppressive function of regulatory T cells

Recent studies have revealed that indoles, dietary ligands of the aryl hydrocarbon receptor (AhR), have immunomodulatory characteristics of balancing the differentiation of regulatory T cells (Tregs) and Th17 cells in multiple autoimmune diseases.In this study, we aimed to investigate the potency of the indole, 3,3′-diindolylmethane (DIM), on the stability and suppressive function of Tregs in experimental autoimmune encephalomyelitis (EAE). Furthermore, we used the AhR antagonist CH223191 to verify that DIM exerts its effects on Tregs through the activation of AhR.We found that DIM treatment significantly alleviated the severity of EAE by maintaining the stability and suppressive function of Tregs instead of facilitating the differentiation of Tregs. Thus, these DIM-treated Tregs might indirectly inhibit the generation of Th17 cells and the production of proinflammatory cytokines. And we confirmed the critical role of AhR in the EAE model.Our study further investigated the mechanisms by which dietary indoles promote Treg activity in the EAE model. DIM may act as a novel therapeutic to restrain autoimmune inflammation in multiple sclerosis.

Anticancer Activity of 3,3′‐Diindolylmethane and the Molecular Mechanism Involved in Various Cancer Cell Lines

AbstractIndole‐3‐carbinol is a natural compound present in cruciferous plants, which upon digestion, converts into 3,3′‐diindolylmethane (DIM) under acidic pH of the stomach. In recent years, various methods have been developed to improve the synthesis of DIM and its analogs because of different pharmacological activities like anticancer, antimicrobial, anti‐inflammatory, etc. Among them, DIMs anticancer activity by modulation of protein expression in cell signaling pathways and other factors has widely studied. This review describes the antiproliferative activity of DIMs and its mode of action, which resulted in apoptosis in various cancerous cells. We have performed a literature search on DIMs anticancer activity over the last ten years (2011–2020) and reported in this review. Several fascinating DIM attributes against cancer suggest it as a potential candidate for further drug development programs. This review will guide the medicinal chemist to find the mechanistic pathways involved in the inhibition of proliferation in cancerous cells by novel DIMs.

Inhibition of endogenous hydrogen sulfide biosynthesis enhances the anti-cancer effect of 3,3′-diindolylmethane in human gastric cancer cells

Aims3,3′-Diindolylmethane (DIM) has limited anti-cancer effects in gastric cancer. Hydrogen sulfide (H2S) plays an important role in the tumor development and therapy, cystathionine-β-synthase (CBS) and cystathionine-γ-lyase (CSE), two key endogenous H2S biosynthesis enzymes, can affect endogenous H2S levels and alter cancer treatment. Our main objective was to investigate whether the aminooxyacetic acid (AOAA) and DL-Propargylglycine (PAG), two specific inhibitors of CBS and CSE, could assist DIM to exert a stronger anti-cancer effects in gastric cancer BGC-823 and SGC-7901 cells. Materials and methodsCell proliferation was assayed by MTT and cell colony-forming assay. Apoptosis and migration were detected by Hoechst staining and scratch test respectively. Western blot was used to evaluate the expression of proteins related to proliferation, apoptosis and migration. Key findingsCombination of AOAA or PAG with DIM synergistically inhibited proliferation and migration, increased apoptosis in gastric cancer cells. The p38-p53 axis was also further activated by the combination of AOAA or PAG with DIM. Exogenous H2S from sodium hydrosulfide, attenuated the efficacy of DIM in cancer cells by reducing the activation level of p38-p53 axis. Taken together, AOAA or PAG inhibited the expression of endogenous H2S biosynthesis enzymes and effectively enhanced susceptibility of gastric cancer to DIM through activating p38-p53 axis. SignificanceThe current study highlight more precise requirements for the clinical application of sulfur-containing anti-cancer drugs, and open a new way to enhance the sensitivity of DIM in chemotherapy of gastric cancer.

Abstract 6513: 3,3'-diindolylmethane enhances tumor regression after radiation through protecting normal cells to modulate anti-tumor immunity

Abstract Preclinical and clinical data indicate that radiotherapy acts as an immune modifier, having both immunostimulatory and immunosuppressive effects on the tumor immune microenvironment (TIME). 3.3'-Diindolylmethane (DIM), the acid-catalyzed dimer of the bioactive indole found in cruciferous vegetables, has long been known for its anticancer properties and has been proposed for use as a cancer prevention agent. The current study characterizes how DIM influences TIME and tumor regression after fractionated radiation treatment using preclinical breast cancer models. We first compared tumor graft models using immune-competent and immune-deficient mouse strains to find out whether immune cells are required for DIM's effects. Tumor targeted radiation was done using narrow-beam radiation with shielding. Tumor regression was monitored after DIM and radiation combined treatment and radiation alone. Our results indicated that DIM enhanced tumor regression after radiation treatment in immune-competent but not immuno-deficient mice. Data from nCounter® PanCancer immune profiling panel showed DIM increased intratumoral immune cells including cytotoxic T cells, neutrophils and macrophages after radiation and enhanced immunological processes such as adhesion and antigen processing. Expression of several MHC Class II molecules and CD74, a gene encoding chaperone and transport cofactor that assists MHC II molecules folding and presenting, significantly increased in the combined treatment of radiation and DIM. The results showing that DIM treatment alone does not affect tumor growth suggested that DIM's radioprotective effect on non-tumoral cells, including stromal cells and immune cells, plays a critical role in promoting a microenvironment that favors anti-tumor immunity. Additional experiments showed that DIM protected normal cells from radiation-caused immediate injuries in vitro and in vivo. In summary, DIM's radioprotective effects on immune cells and other normal cells are important in promoting a TIME that favors anti-tumor immunity. As a result, DIM increases the efficacy of radiation treatment on tumor regression. This study supports the development of DIM as an adjunct agent for radiation treatment. Citation Format: Renxiang Chen, Lijun Li, Yun-Tien Lin, Arslon Humayun, Albert J. Fornace Jr., Heng-Hong Li. 3,3'-diindolylmethane enhances tumor regression after radiation through protecting normal cells to modulate anti-tumor immunity [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 6513.

Modulatory Effect of Indoles on the Expression of miRNAs Regulating G1/S Cell Cycle Phase in Breast Cancer Cells.

Indole-3-carbinol (I3C) is a naturally occurring glucosinolate found in Brassica vegetables that is usually converted in gastric acidic environment to the efficient metabolite 3,3'-diindolylmethane (DIM). Both indoles (I3C and DIM) are known chemopreventive agents for various cancers including breast cancer. This study aimed to investigate the influence of both indoles on the tumor suppressor miRNAs (let-7a-e, miR-15a, miR-16, miR-17-5p, miR-19a, and miR-20a) and oncomiRs (miR-181a, miR-181b, miR-210, miR-221, and miR-106a), which are controlling the cell cycle key regulators: cyclin-dependent kinases (CDKs), CDK inhibitor p27Kip1, and cyclin D1. Our results indicated that both indoles generally elevated the expression of the tumor suppressor miRNAs let-7a-e, miR-19a, miR-17-5p, and miR-20a and decreased the expression of the oncomiR list. Both indoles were able to significantly suppress the expression of CDK4 and CDK6 as well as the apoptotic markers Bcl-2 and survivin. Both indoles decreased cyclin-D1 protein, where I3C decreased cytoplasmic and nuclear cyclin-D1 significantly. Cytoplasmic and nuclear P27Kip1 showed overexpression following treatment with I3C higher than that detected following DIM treatment. This study provides a mechanistic elucidation of the previously reported cell cycle arrest by I3C and DIM in breast cancer cells suggesting that this effect could be through modulation of miRNAs expression that, in turn, regulates the genetic network controlling the G1/S phase in cell cycle progression.

Chemopreventive Agent 3,3'-Diindolylmethane Inhibits MDM2 in Colorectal Cancer Cells.

3,3′-Diindolylmethane (DIM) is a naturally derived chemopreventive compound. It comes from glucobrassicin, an indole glucosinolate enriched in cruciferous vegetables, and is formed in the acidic environment of the stomach after ingestion. Mouse double minute 2 homolog (MDM2) is an important, multi-functional oncogenic protein and it has been well recognized for its negative regulation of the tumor suppressor protein p53. We discovered a novel mechanism of action of DIM, that it directly inhibits MDM2 in multiple colorectal cancer (CRC) cell lines. Treatment with DIM decreased MDM2 at messenger RNA (mRNA) and protein levels, inhibited cancer cell proliferation, and induced cell cycle arrest and apoptosis. DIM-induced decrease of MDM2 is p53-independent and is partly mediated by proteasome degradation of MDM2, as blocking of the proteasome activity reversed MDM2 protein inhibition. Overexpression of MDM2 blocked DIM’s effects in growth suppression and apoptosis induction. When combined with imidazoline MDM2 inhibitors (Nutlin-3a and Idasanutlin/RG-7388), synergism was observed in cancer cell growth inhibition. In summary, our data support a new mechanism of action for DIM in direct inhibition of MDM2. The identification of MDM2 as a novel DIM target may help develop a new strategy in CRC prevention.

3,3\u2032-Diindolylmethane modulates aryl hydrocarbon receptor of esophageal squamous cell carcinoma to reverse epithelial-mesenchymal transition through repressing RhoA/ROCK1-mediated COX2/PGE2 pathway

BackgroundEsophageal squamous cell carcinoma (ESCC) is one of the most aggressive tumors in the world. Aryl hydrocarbon receptor (AHR) has been reported to promote tumor metastasis and epithelial-mesenchymal transition (EMT) is a vital process of conferring cancer cells capabilities of migration and invasion. However, the mechanism by which modulation of AHR can inhibit tumor metastasis remains unknown. Thus, we aim to investigate the underlying mechanism regarding reversing EMT process of ESCC through modulation of AHR.MethodsWe used AHR selective modulator 3,3′-diindolylmethane (DIM) to treat ESCC cell lines TE1 and KYSE150 so as to examine alterations of migration and invasion by wound healing and Transwell assay. Western blotting (WB) and qPCR were performed to detect relative genes and proteins changes regarding EMT process. Cell transfection was utilized for confirming pathways involved in DIM-induced reversal of EMT and in vivo assay was conducted for verification of the underlying mechanism. Co-IP assay was conducted for detecting protein-protein interactions.ResultsAHR was overexpressed in ESCC and modulation of AHR by DIM could inhibit migration and invasion as well as downregulate mesenchymal cell markers β-Catenin, Vimentin and Slug and upregulate epithelial cell marker Claudin-1. Meanwhile, synergically overexpression of AHR, RhoA and ROCK1 correlated with poor clinical outcomes. DIM could inhibit COX2/PGE2 pathway by targeting AHR, and COX2 selective inhibitor Celecoxib could suppress EMT and metastasis. Results of PGE2 treatment were opposite to that of Celecoxib. Meanwhile, blockade of RhoA/ROCK1 pathway also exerted prohibitive effects on EMT and metastasis. WB results showed COX2/PGE2 pathway could be regulated by RhoA/ROCK1 pathway and DIM could inhibit RhoA/ROCK1 pathway through modulation of AHR. In vivo assay verified the results in vitro. Co-IP results showed DIM could modulate AHR to reverse EMT directly through inhibition of interaction between AHR and EGFR (epidermal growth factor receptor) so as to block RhoA/ROCK1-mediated COX2/PGE2 pathway which was connected by NF-κB.ConclusionsIn brief, modulation of AHR by DIM can reverse EMT process and inhibit metastasis of ESCC through repressing RhoA/ROCK1-mediated COX2/PGE2 pathway.

Effect of Ultrasound Treatment on Physicochemical, Microstructural and Anti-Oxidative Properties of Whey Protein Concentrate Based 3,3′-Diindolylmethane Nanoparticles

Abstract Objectives This study evaluated the impact of ultrasound duration on the encapsulation of 3,3′-diindolylmethane (DIM) using whey protein concentrate nanoparticles. Methods Whey protein concentrate-based DIM nanoparticles were prepared and treated with different ultrasound times (0 - 20 min) with 30% amplitude. Results The results showed that ultrasound treatment significantly decreased the particle size (from 265 nm to 218 nm) and PDI value (from 0.49 to 0.43); as well as zeta potential values were notably increased. The encapsulation efficiency (EE%) increased with increasing sonication time (0–20 min) from 76% to 77, 79, 81, and 88%, respectively. The ultrasound treatment had a significant effect on the apparent viscosity, and decrease in the viscosity as a function of shear rate was observed with increasing sonication time. The transmission electronic microscopy (TEM) micrographs demonstrated that all the formulations treated with different sonication times had a smooth and uniform spherical shape and ultrasound treatment led to the reduction of particle size, especially for 20 min of ultrasound. The thermal stability of the WPC–DIM nanoparticles were enhanced with increasing sonication time by increasing peak denaturation temperature and enthalpy. The Fourier transform infrared spectroscopy (FT-IR) spectra analysis revealed that ultrasound treatment had a remarkable effect on the secondary structure of WPC–DIM nanoparticles, and electrostatic interactions and hydrogen bonds between DIM and whey protein were strengthened. Moreover, the length of ultrasound treatment exhibited a significant effect on the DPPH (2,2-diphenyl-2-picrylhydrazyl) scavenging activity (from 56% to 62%) and ABTS(2,2′-azinobis(2 ethylbenzothiazoline-6-sulfonate) scavenging activity (from 47% to 68%). Conclusions In conclusion, the ultrasound treatment successfully improved the physicochemical, microstructural, and anti-oxidative properties of WPC–DIM nanoparticles, therefore it is considered an efficient method for the development of whey protein concentrate-based DIM nanoparticles to be used for medical and nutritional applications. Funding Sources Northeast Agricultural University.

3,3'-Diindolylmethane (DIM): A nutritional intervention and its impact on breast density in healthy BRCA carriers compared to non-treated carriers—A prospective clinical trial.

1556 Background: Women who carry the BRCA mutation are at high lifetime risk of breast cancer, but there is no consensus regarding an effective and safe chemoprevention strategy. A large body of evidence suggests that 3,3-diindolylmethane (DIM), a dimer of indole-3-carbinol (I3C) found in cruciferous vegetables, can potentially prevent carcinogenesis and tumor development. The primary aim of this prospective study was to investigate the effect of DIM supplementation on breast density, a recognized predictive factor of breast-cancer risk. Methods: Participants were 23 healthy female BRCA carriers (median age 47 years; 78% postmenopausal) who were treated with oral DIM 100 mgx1/d for one year. The amount of fibroglandular tissue (FGT) and background parenchymal enhancement (BPE) on magnetic resonance imaging (MRI) performed before and after the intervention were scored by two independent expert radiologists using the Breast Imaging and Reporting Data System (BI-RADS). Each woman in the cohort was matched by age (within 3 years) and menopausal status to a woman attending the clinic who was not participating in the study and who underwent breast MRI in parallel year. Results: A decrease in the average score for FGT amount from 2.8±0.8 at onset to 2.65±0.842.8 after one year (p = 0.031), with no significant change in BPE (p = 0.429). A group of DIM-untreated age- and menopausal-status-matched clinic patients did not show a significant change in FGT amount (p = 0.33) or BPE (p = 0.814) in a parallel year. Mean estradiol level decreased from 159 to 102 pmol/L (p = 0.01), and mean testosterone level, from 0.42 to 0.31 pmol/L (p = 0.007). Side effects were grade 1. Conclusions: One year’s supplementation with DIM 100 mgX1/d in BRCA carriers was associated with a significant decline in FGT amount on MRI. Larger randomized studies are warranted to corroborate these findings. Clinical trial information: NCT02197000.

Synthesis of diindolylmethane (DIM) bearing thiadiazole derivatives as a potent urease inhibitor

The current study describes synthesis of diindolylmethane (DIM) derivatives based-thiadiazole as a new class of urease inhibitors. Diindolylmethane is natural product alkaloid reported to use in medicinal chemistry extensively. Diindolylmethane-based-thiadiazole analogs (1–18) were synthesized and characterized by various spectroscopic techniques 1HNMR, 13C-NMR, EI-MS and evaluated for urease (jack bean urease) inhibitory potential. All compounds showed excellent to moderate inhibitory potential having IC50 value within the range of 0.50 ± 0.01 to 33.20 ± 1.20 µM compared with the standard thiourea (21.60 ± 0.70 µM). Compound 8 (IC50 = 0.50 ± 0.01 µM) was the most potent inhibitor amongst all derivatives. Structure-activity relationships have been established for all compounds. The key binding interactions of most active compounds with enzyme were confirmed through molecular docking studies.

Effect of 3,3'-Diindolylmethane on Pulmonary Injury Following Thoracic Irradiation in CBA Mice.

The molecule 3,3'-diindolylmethane (DIM) is small, a major bioactive metabolite of indole-3 carbinol (13C), and a phytochemical compound from cruciferous vegetables released upon exposure to the gut acid environment. DIM is a proposed anti-cancer agent and was previously demonstrated to prevent radiation damage in the bone marrow and the gastrointestinal tract. Here we investigated the effect of DIM on radiation-induced injury to the lung in a murine model through untargeted metabolomics and gene expression studies of select genes. CBA mice were exposed to thoracic irradiation (17.5 Gy). Mice were treated with vehicle or DIM (250 mg kg, subcutaneous injection) on days -1 pre-irradiation through +14 post-irradiation. DIM induced a significant improvement in survival by day 150 post-irradiation. Fibrosis-related gene expression and metabolomics were examined using lung tissue from days 15, 45, 60, 90, and 120 post-irradiation. Our qRT-PCR experiments showed that DIM treatment reduced radiation-induced late expression of collagen Iα and the cell cycle checkpoint proteins p21/waf1 (CDKN1A) and p16ink (CDKN2A). Metabolomic studies of lung tissue demonstrated a significant dampening of radiation-induced changes following DIM treatment. Metabolites associated with pro-inflammatory responses and increased oxidative stress, such as fatty acids, were suppressed by DIM treatment compared to irradiated samples. Together these data suggest that DIM reduces radiation-induced sequelae in the lung.

Indole-3-Carbinol Derivative DIM Mitigates Carbon Tetrachloride-Induced Acute Liver Injury in Mice by Inhibiting Inflammatory Response, Apoptosis and Regulating Oxidative Stress.

3,3′-Diindolylmethane (DIM), a metabolic product of indole-3-carbinol extracted from cruciferous vegetables exhibits anti-inflammatory and anti-cancer properties. Earlier, the product has been demonstrated to possess anti-fibrotic properties; however, its protective effects on liver injury have not been clearly elucidated. In this study, we postulated the effects and molecular mechanisms of action of DIM on carbon tetrachloride (CCl4)-induced liver injury in mice. Acute liver injury was induced by a single intraperitoneal administration of CCl4 (1 ml/kg) into mice. DIM was injected via subcutaneous route for three days at various doses (2.5, 5 and 10 mg/kg) before CCl4 injection. Mice were sacrificed and serum was collected for quantification of serum transaminases. The liver was collected and weighed. Treatment with DIM significantly reduced serum transaminases levels (AST and ALT), tumor necrosis factor-α (TNF-α) and reactive oxygen species (ROS). CCl4- induced apoptosis was inhibited by DIM treatment by the reduction in the levels of cleaved caspase-3 and Bcl2 associated X protein (Bax). DIM treated mice significantly restored Cytochrome P450 2E1, nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) expression in CCl4 treated mice. In addition, DIM downregulated overexpression of hepatic nuclear factor kappa B (NF-κB) and inhibited CCl4 mediated apoptosis. Our results suggest that the protective effects of DIM against CCl4- induced liver injury are due to the inhibition of ROS, reduction of pro-inflammatory mediators and apoptosis.

Nanoformulated Bioactive Compounds Derived from Different Natural Products Combat Pancreatic Cancer Cell Proliferation.

PurposeThis study was designed to determine the potential effect of nanoencapsulated bioactive compounds from different natural sources on human pancreatic cancer.BackgroundPancreatic cancer carries the highest fatality rate among all human cancers because of its high metastatic potential and late presentation at the time of diagnosis. Hence there is a need for improved methods to prevent and treat it. Natural products, such as 3, 3′-diindolylmethane (DIM) and ellagic acid (EA) demonstrated anticancer efficacy against various cancer types. However, DIM is insoluble. Hence, using nanotechnology to encapsulate these compounds in combination with EA might improve their physical and chemical properties and their delivery to the cancer cells.MethodsHuman pancreatic cancer cells, namely SUIT2-luciferase transfected, were used to examine the effects of DIM or EA and their nanoformulation in poly(lactic-co-glycolic acid) (PLGA) and poly(ethylene glycol) (PEG) [PLGA-PEG] nanoparticles (NPs) on SUIT2-luciferase cell viability/proliferation over 24 hrs. Additionally, effects on tumor weight and angiogenesis were determined using the chick chorioallantoic membrane (CAM) tumor implant model.ResultsBoth DIM and EA PLGA-PEG NPs resulted in rapid suppression of pancreatic cancer cell viability/proliferation within 24 hrs (P < 0.01), while the non-encapsulated DIM and EA did not show any significant effect on SUIT2 cancer cell viability or cell proliferation (MTT assay). In the CAM pancreatic cancer cell (SUIT2) implant model, results showed a greater suppression of tumor weight (P < 0.01), tumor cell viability, and tumor angiogenesis (P < 0.01) for DIM NPs and EA NPs and their combinations versus DIM or EA alone.ConclusionNanoformulation of DIM and EA resulted in a more effective suppression of pancreatic cancer cell viability, pancreatic tumor weight, implanted cancer cell viability, and tumor angiogenesis as compared with these bioactive compounds alone.

Modulation of aryl hydrocarbon receptor inhibits esophageal squamous cell carcinoma progression by repressing COX2/PGE2/STAT3 axis.

Esophageal squamous cell carcinoma (ESCC) is one of the most common malignant tumors with poor prognosis. Aryl hydrocarbon receptor (AHR) is a ligand-dependent transcription factor and emerging evidence shows it is associated with tumor initiation and promotion. However, the relationship between AHR and ESCC is not clear and it is meaningful to explore whether AHR could be a therapeutic target. In the present study, immunohistochemistry was performed to determine AHR expression levels in ESCC tissues. Knockdown of AHR expression in ESCC cell lines genetically and modulation of AHR by 3, 3'-diindolylmethane (DIM) pharmacologically both in vitro and in vivo were utilized to examine the corresponding alterations in cell growth, migration and invasion. Our study indicated that AHR expression levels were elevated in ESCC and associated with poor prognosis. Both knockdown and modulation of AHR inhibited tumor progression through down-regulating expression levels of PCNA, Bcl-2, Cyclin D1, MMP1, MMP2, MMP9 and up-regulating expression levels of Bax, Cleaved-Caspase 3. Our findings also indicated that repressing COX2/PGE2/STAT3 axis exerted inhibitory effects on ESCC both in vitro and in vivo assays. Taken together, AHR plays the key role in ESCC progression and targeting AHR as a therapeutic strategy with DIM is deserved for further exploration.