Synthesis and in vitro evaluation of homoisoflavonoids as potent inhibitors of nitric oxide production in RAW-264.7 cells.

Syntheses of natural homoisoflavonoids, (±)-portulacanones A-C (4, 8 and 9), portulacanone D (6), isolated from Portulaca oleracea L. (POL) and their derivatives (3, 5 and 7) have been achieved for the first time along with the synthesis of known derivatives (1 and 2) and their in vitro inhibitory effect against NO production in LPS-induced RAW-264.7 macrophages was evaluated as an indicator of anti-inflammatory activity. All the compounds tested had a concentration-dependent inhibitory effect on NO production by RAW-264.7 macrophages without obvious cytotoxicity. Compounds 3 (97.2% at 10 µM; IC50 = 1.26 µM) followed by 6 (portulacanone D) (92.5% at 10 µM; IC50 = 2.09 µM), 1 (91.4% at 10 µM; IC50 = 1.75 µM) and 7 (83.0% at 10 µM; IC50 = 2.91 µM) were the most potent from the series. This finding was further correlated with the suppressed expression of iNOS induced by LPS. Our promising preliminary results may provide the basis for the assessment of compound 3 as a lead structure for a NO production-targeted anti-inflammatory drug development and also could support the usefulness of POL as a folklore medicinal plant in the treatment of inflammatory diseases.

Hindsiipropane B alleviates HIV-1 Tat-induced inflammatory responses by suppressing HDAC6-NADPH oxidase-ROS axis in astrocytes.

Human immunodeficiency virus-1 (HIV-1) transactivator of transcription (Tat) is an important viral factor in neuroinflammation. Hindsiipropane B, present in Celastrus hindsii, possesses various biological mechanisms including antiinflammatory activity. In this report, we explored the regulatory activity of hindsiipropane B on HIV-1 Tat-mediated chemokine production and its mode of action in astrocytes. Hindsiipropane B significantly alleviated HIV-1 Tat-mediated production of inflammatory chemokines, CCL2, CXCL8, and CXCL10. Hindsiipropane B inhibited expression of HDAC6, which is important regulator in HIV-1 Tat-mediated chemokine production. Hindsiipropane B diminished HIV-1 Tat-mediated reactive oxygen species (ROS) generation and NADPH oxidase activation/expression. Furthermore, hindsiipropane B inhibited HIV-1 Tat-mediated signaling cascades including MAPK, NF-κB, and AP-1. These data suggest that hindsiipropane B exerts its inhibitory effects on HIV-1 Tat-mediated chemokine production via down-regulating the HDAC6-NADPH oxidase-MAPK-NF-κB/AP-1 signaling axis, and could serve as a therapeutic lead compound against HIV-1 Tat-associated neuroinflammation. [BMB Reports 2018; 51(8): 394-399].

Dihydrostilbenes and diarylpropanes: Synthesis and in vitro pharmacological evaluation as potent nitric oxide production inhibition agents.

An efficient synthesis of dihydrostilbenes (1-5) and diarylpropanes (6-10) is achieved from the commercially available starting materials and Wittig-Horner reaction, Claisen-Schmidt condensation and hydrogenation as key steps. Later, their nitric oxide (NO) production inhibition effects were evaluated in lipopolysaccharide (LPS)-induced RAW-264.7 macrophages as an indicator of anti-inflammatory activity. All the tested compounds significantly decreased NO production in a concentration-dependent manner except compounds 2, 6 and 8 and did not show notable cytotoxicity except compound 1. Two compounds i.e., compound 9 (hindsiipropane B) (100%; IC50=1.84µM) possessed the most potent NO inhibitory activity which was even stronger than the positive control, L-NMMA (90.1%; IC50=2.73µM) followed by compound 4 (75.5%; IC50=2.98µM) at 10µM concentration and this finding was also further correlated by suppressed expression of LPS stimulated inducible NO synthase. Our study revealed that compound 9, a 1,3-diarylpropane scaffold with 3″,4″-dimethoxyphenyl and 3',4'-dihydroxy-2'-methoxyphenyl motifs could be considered as potential compound or lead compound for further development of NO production-targeted anti-inflammatory agents.

Syntheses and Anti-inflammatory Activity of Natural 1,3-Diarylpropenes.

First syntheses of five natural 1,3-diarylpropenes (cinnamylphenols) 2-4, 7, and 8 along with synthesis of two other natural 1,3-diarylpropenes 1 and 5 and E-isomer of mucronulastyrene (6) were achieved by Friedel-Crafts alkylation as a key step. Subsequently, their anti-inflammatory effects were also investigated in lipopolysaccharide (LPS)-induced RAW264.7 macrophages. The compounds exhibited significant inhibition of inflammatory mediated nitric oxide (NO) production with no cytotoxicity except compound 8 (dalberatin B) at 10 µM concentration and IC50 values were found in the range from 4.05 to 16.76 µM.

Synthesis and biological evaluation of 2-aroylbenzofurans, rugchalcones A, B and their derivatives as potent anti-inflammatory agents.

An efficient synthesis of 2-aroylbenzofurans, rugchalcones A, B and their derivatives was accomplished in excellent yields by the Rap-Stoermer reaction between substituted salicylaldehydes and phenacyl bromides. Later their anti-inflammatory effects were evaluated in lipopolysaccharide (LPS)-induced RAW-264.7 macrophages. The compounds were exhibited exceptional potency against inflammatory mediated NO production with no cytotoxicity at 10 µM concentration and IC50 values are found in the range from 0.75 to 13.27 µM. Among the 2-aroylbenzofurans prepared in this study, compounds 4 (99.6%; IC50=0.57), rugchalcone B (2) (99.3%; IC50=4.13), 7 (96.8%; IC50=1.90) and 8 (74.3%; IC50=0.99) were showed the maximum inhibitory activity. This study suggests that compounds 2, 4, 7 and 8 which are having 4-hydroxyphenyl group and/or hydroxy (-OH) group at 5- and/or 6-position of benzofuran motif could be considered as a promising scaffolds for the further development of iNOS inhibitors for potential anti-inflammatory applications.

Synthesis and biological evaluation of piperlongumine derivatives as potent anti-inflammatory agents.

Piperlongumine (PL) and its derivatives were synthesized by the direct reaction between acid chloride of 3,4,5-trimethoxycinnamic acid and various amides/lactams. Later their anti-inflammatory effects were evaluated in lipopolysaccharide (LPS)-induced RAW-264.7 macrophages. Of the piperlogs prepared in this study, the maximum (91%) inhibitory activity was observed with PL (IC50=3 µM) but showed cytotoxicity whereas compound 3 (IC50=6 µM) which possess α,ß-unsaturated γ-butyrolactam moiety offered good level (65%) of activity with no cytotoxicity. This study revealed that amide/lactam moiety connected to cinnamoyl group with minimum 3 carbon chain length and α,ß-unsaturation is fruitful to show potent anti-inflammatory activity.

(E)-3-(3,4-dihydroxy-2-methoxyphenyl)-1-(2,4-dihydroxyphenyl)prop-2-en-1-one, a novel licochalcone B derivative compound, suppresses lipopolysaccharide-stimulated inflammatory reactions in RAW264.7 cells and endotoxin shock in mice.

Activated macrophages mediate inflammation, as they release nitric oxide and pro-inflammatory cytokines in various inflammatory diseases. Suppressing macrophage activation may alleviate inflammatory processes. Here, we report that (E)-3-(3,4-dihydroxy-2-methoxyphenyl)-1-(2,4-dihydroxyphenyl)prop-2-en-1-one (DDP), a novel licochalcone B derivative compound, inhibits inflammatory reactions in macrophages and protects mice from endotoxin shock. In vitro experiments showed that DDP suppressed the generation of nitric oxide and pro-inflammatory cytokines by suppressing the activation of nuclear factor-κB and activator protein-1 and simultaneously inhibited its upstream inflammatory signaling cascades in lipopolysaccharide in RAW264.7 cells. In an animal model, DDP protected BALB/c mice from lipopolysaccharide-induced endotoxin shock, possibly through inhibition of the production of inflammatory cytokines. DDP inhibited the production of inflammatory mediators and may be a potential target for treatment of various inflammatory diseases.

Synthesis of licochalcone analogues with increased anti-inflammatory activity.

Licohalcones have been reported to have various biological activities. However, most of licochalcones also showed cytotoxicity even though their versitile utilities. Licochalcones B and D, which have common substituents at aromatic ring B, are targeted to modify the structure at aromatic ring A for inflammatory studies. Licochalcone derivatives (1-6) thus prepared are compared for their suppression ability of nitric oxide (NO) production and showed 9.94, 4.72, 10.1, 4.85, 2.37 and 4.95µM of IC50 values, respectively.

Neuroprotective effect of a new synthetic aspirin-decursinol adduct in experimental animal models of ischemic stroke.

Stroke is the second leading cause of death. Experimental animal models of cerebral ischemia are widely used for researching mechanisms of ischemic damage and developing new drugs for the prevention and treatment of stroke. The present study aimed to comparatively investigate neuroprotective effects of aspirin (ASA), decursinol (DA) and new synthetic aspirin-decursinol adduct (ASA-DA) against transient focal and global cerebral ischemic damage. We found that treatment with 20 mg/kg, not 10 mg/kg, ASA-DA protected against ischemia-induced neuronal death after transient focal and global ischemic damage, and its neuroprotective effect was much better than that of ASA or DA alone. In addition, 20 mg/kg ASA-DA treatment reduced the ischemia-induced gliosis and maintained antioxidants levels in the corresponding injury regions. In brief, ASA-DA, a new synthetic drug, dramatically protected neurons from ischemic damage, and neuroprotective effects of ASA-DA may be closely related to the attenuation of ischemia-induced gliosis and maintenance of antioxidants.

2-(4-Hydroxyphenyl)-5-(3-Hydroxypropenyl)-7-Methoxybenzofuran, a Novel Ailanthoidol Derivative, Exerts Anti-Inflammatory Effect through Downregulation of Mitogen-Activated Protein Kinase in Lipopolysaccharide-Treated RAW 264.7 Cells.

We reported that ailanthoidol, a neolignan from Zanthoxylum ailanthoides and Salvia miltiorrhiza Bunge, inhibited inflammatory reactions by macrophages and protected mice from endotoxin shock. We examined the anti-inflammatory activity of six synthetic ailanthoidol derivatives (compounds 1-6). Among them, compound 4, 2-(4-hydroxyphenyl)-5-(3-hydroxypropenyl)-7-methoxybenzofuran, had the lowest IC50 value concerning nitric oxide (NO) release from lipopolysaccharide (LPS)-stimulated RAW264.7 cells. Compound 4 suppressed the generation of prostaglandin (PG) E2 and the expression of inducible NO synthase and cyclooxygenase (COX)-2 induced by LPS, and inhibited the release of LPS-induced pro-inflammatory cytokines from RAW264.7 cells. The underlying mechanism of compound 4 on anti-inflammatory action was correlated with the down-regulation of mitogen-activated protein kinase and activator protein-1 activation. Compound 4 is potentially an effective functional chemical candidate for the prevention of inflammatory diseases.

Licochalcone E present in licorice suppresses lung metastasis in the 4T1 mammary orthotopic cancer model.

We investigated whether licochalcone E (LicE), a phenolic constituent of licorice, inhibits mammary tumor growth and metastasis using animal and cell culture models. 4T1 mammary carcinoma cells were injected into the mammary fat pads of syngeneic BALB/c mice. Starting 7 days after the injection, the mice received LicE (7 or 14 mg/kg body weight/day) via oral gavage for 25 days. LicE suppressed solid tumor growth and lung metastasis, but did not exhibit kidney or liver toxicity. In tumor tissues, LicE treatment induced a reduction in the expression of Ki67, cyclins, and cyclin-dependent kinases and stimulated apoptosis with increased expression of Bax and cleaved caspase-3 but decreased expression of Bcl-2. In addition, LicE decreased expression of CD31, vascular endothelial growth factor (VEGF)-A and C, VEGF-receptor 2, lymphatic vessel endothelial receptor-1, CD45, cyclooxygenase-2, inducible nitric oxide synthase, and hypoxia inducible factor-1α in tumor tissues. In lung tissues, LicE reduced the levels of proinflammatory cytokines and angiogenesis/metastasis-related proteins. In mammary cancer cell cultures, LicE (5-20 µmol/L) dose dependently inhibited cell migration and invasion. LicE inhibited secretion of matrix metalloproteinase-9, urokinase-type plasminogen activator and VEGF-A, and stimulated secretion of tissue inhibitor of metalloproteinase-2 in MDA-MB-231 cells. In addition, LicE inhibited tube formation of vascular endothelial cells. We show that LicE administration suppressed tumor growth and lung metastasis in the mouse model in conjunction with LicE inhibition of cell migration, invasion, and tube formation in vitro. Reduced tumor growth and metastasis in LicE-treated mice may be, at least in part, attributed to reduced inflammation and tumor angiogenesis.

XH-14, a novel danshen methoxybenzo[b]furan derivative, exhibits anti-inflammatory properties in lipopolysaccharide-treated RAW 264.7 cells.

BACKGROUND: XH-14 isolated from Salvia miltiorrhiza is a bioactive component and adenosine antagonist. In the present study, we evaluated anti-inflammatory properties of XH-14 in murine macrophages. METHODS: RAW 264.7 murine macrophage cell line was cultured with various concentrations of XH-14 in the absence or presence of lipopolysaccharide (LPS). LPS-induced release and mRNA expression of inflammatory mediators were examined by ELISA and real-time PCR. The modification of signal pathways involved in inflammatory reactions was determined by Western blotting analysis. RESULTS: XH-14 suppressed the generation of nitric oxide (NO) and prostaglandin E2, and the expression of inducible NO synthase and cyclooxygenase-2 induced by LPS. Similarly, XH-14 inhibited the release of pro-inflammatory cytokines induced by LPS in RAW 264.7 cells. The underlying mechanism of XH-14 on anti-inflammatory action was correlated with down-regulation of mitogen-activated protein kinase and activator protein-1 activation. CONCLUSIONS: XH-14 inhibits the production of several inflammatory mediators and so might be useful for the treatment of various inflammatory diseases.

Piceatannol inhibits migration and invasion of prostate cancer cells: possible mediation by decreased interleukin-6 signaling.

Piceatannol (trans-3,4,3',5'-tetrahydroxystilbene) is a polyphenol detected in grapes, red wine and Rheum undulatum; it has also been demonstrated to exert anticarcinogenic effects. In this study, in order to determine whether piceatannol inhibits the lung metastasis of prostate cancer cells, MAT-Ly-Lu (MLL) rat prostate cancer cells expressing luciferase were injected into the tail veins of male nude mice. The oral administration of piceatannol (20 mg/kg) significantly inhibited the accumulation of MLL cells in the lungs of these mice. In the cell culture studies, piceatannol was demonstrated to inhibit the basal and epidermal growth factor (EGF)-induced migration and invasion of DU145 cells, in addition to the migration of MLL, PC3 and TRAMP-C2 prostate cancer cells. In DU145 cells, piceatannol attenuated the secretion and messenger RNA levels of matrix metalloproteinase-9, urokinase-type plasminogen activator (uPA) and vascular endothelial growth factor (VEGF). Piceatannol increased the protein levels of tissue inhibitor of metalloproteinase-2 in a concentration-dependent fashion. Additionally, piceatannol inhibited the phosphorylation of signal transducer and activator of transcription (STAT) 3. Furthermore, piceatannol effected reductions in both basal and EGF-induced interleukin (IL)-6 secretion. An IL-6 neutralizing antibody inhibited EGF-induced STAT3 phosphorylation and EGF-stimulated migration of DU145 cells. Interleukin-6 treatment was also shown to enhance the secretion of uPA and VEGF, STAT3 phosphorylation and the migration of DU145 cells; these increases were suppressed by piceatannol. These results demonstrate that the inhibition of IL-6/STAT3 signaling may constitute a mechanism by which piceatannol regulates the expression of proteins involved in regulating the migration and invasion of DU145 cells.

Ailanthoidol suppresses lipopolysaccharide-stimulated inflammatory reactions in RAW264.7 cells and endotoxin shock in mice.

The biological properties of ailanthoidol, a neolignan from Zanthoxylum ailanthoides or Salvia miltiorrhiza Bunge, which is used in Chinese traditional herbal medicine, have not been evaluated. Here, we report that ailanthoidol inhibits inflammatory reactions in macrophages and protects mice from endotoxin shock. Our in vitro experiments showed that ailanthoidol suppressed the generation of nitric oxide (NO) and prostaglandin E(2) , as well as the expression of inducible NO synthase (iNOS) and cyclooxygenase (COX)-2 induced by lipopolysaccharide (LPS) in RAW264.7 cells. Similarly, ailanthoidol inhibited the production of inflammatory cytokines induced by LPS in RAW264.7 cells, including interleukin (IL)-1ß and IL-6. In an animal model, ailanthoidol protected BALB/c mice from LPS-induced endotoxin shock, possibly through inhibition of the production of inflammatory cytokines and NO. Collectively, ailanthoidol inhibited the production of inflammatory mediators and may be a potential target for treatment of various inflammatory diseases.

Celastrol induces expression of heme oxygenase-1 through ROS/Nrf2/ARE signaling in the HaCaT cells.

We previously demonstrated that celastrol, a quinone methide triterpenoid derived from the medicinal plant Tripterygium wilfordii, exerts its anti-inflammatory activity through up-regulation of heme oxygenase-1 (HO-1) expression in the keratinocytes. In this study, we examined the signaling pathways that lead to the up-regulation of HO-1 expression by celastrol. In HaCaT cells, celastrol-induced HO-1 expression was dependent on ROS generation. ERK and p38 MAPK were major MAPK pathways responsible for celastrol-induced HO-1 expression. Celastrol induced Nrf2 activation. Nrf2 knockdown using small interfering RNA (siRNA) inhibited celastrol-induced HO-1 expression. Treatment with celastrol resulted in a marked increase in antioxidant response element (ARE)-driven transcriptional activity, which was dependent on ROS generation and activation of ERK and p38 MAPK. Furthermore, Nrf2 siRNA significantly reversed the inhibitory effect of celastrol on IFN-γ-induced expression of ICAM-1 in the keratinocytes. Taken together, our results indicate that celastrol can activate the ROS-ERK/p38-Nrf2-ARE signaling cascades leading to the up-regulation of HO-1 which is partly responsible for its anti-inflammatory activity in the keratinocytes.

Novel Danshen methoxybenzo[b]furan derivative antagonizing adipogenic differentiation and production of inflammatory adipokines.

Many benzo[b]furan lignans are known to be biologically active in nature. 2-(3'-Methoxy-4'-hydroxy-phenyl)-5-(3-hydroxypropyl)-7-methoxy-benzo[b]furan-3-carbaldehyde (XH-14) is found as a bioactive component isolated from the plant Salvia miltiorrhiza, commonly known as Danshen, which is a traditional Chinese medicine that is used as a cardiovascular medication. This study examined whether 3 different XH-14 derivatives can inhibit adipocyte differentiation and induction of the adipokines visfatin and resistin in 3T3-L1 adipocytes. Adipocytes were cultured and differentiated in Dulbecco's modified Eagle medium containing fetal bovine serum, 3-isobytyl-1-methylxanthine, dexamethasone, and insulin for 6-8d in the absence and presence of 1-25µM XH-14-derived benzo[b]furan derivatives. Nontoxic 2-(3'-methoxy-4'-hydroxy-phenyl)-6-(3-hydroxypropyl)-5-methoxy-benzo[b]furan (5-MBF) at ≥5µM attenuated cellular lipid accumulation and down-regulated induction of peroxisome proliferator activated receptors γ (PPARγ) and CCAAT enhancer binding protein α (C/EBPα) in a dose-dependent manner, as evidenced by Oil Red O staining and Western blot analysis. Such inhibition of PPAR( and C/EBP( by 5-MBF was achieved at transcriptional mRNA levels. However, 2-(3'-methoxy-4'-hydroxy-phenyl)-5-(3-hydroxypropyl)-7-methoxy-benzo[b]furan (7-MBF) and 2-(3'-methoxy-4'-hydroxy-phenyl)-5-(3-hydroxypropyl)-7-methoxy-benzo[b]furan (6-MBF) had minimal effects on adipogenic differentiation, suggesting a structure-activity relationship of methoxybenzo[b]furan derivatives as an inhibitor of adipogenic differentiation. Furthermore, ≥5µM 5-MBF retarded protein and mRNA expression of proinflammatory and insulin resistance-enhancing adipokines of visfatin and resistin in differentiated adipocytes. Induction of visfatin and resistin was, at least in part, mediated via adipocyte differentiation-associated activation of PPARγ signal targeting adipocyte protein 2 and stearoyl-CoA desaturase. These results demonstrate that the 2-(3'-methoxy-4'-hydroxy-phenyl)-3-hydroxypropyl benzo[b]furan lignan, with a methoxy group at the 5-position on the benzene ring, may be a promising agent for disturbance of adipogenic differentiation and for blockage of obesity-associated inflammatory and metabolic diseases.

Celastrol suppresses IFN-gamma-induced ICAM-1 expression and subsequent monocyte adhesiveness via the induction of heme oxygenase-1 in the HaCaT cells.

Celastrol, a quinone methide triterpenoid derived from the medicinal plant Tripterygium wilfordii, possesses various biological activities such as anti-oxidant, anti-tumor, and anti-inflammatory activities. In this study, we examined the suppressive effect of celastrol on IFN-gamma-induced expression of ICAM-1 and the molecular mechanism responsible for these activities. We found that celastrol induced mRNA and protein expression of heme oxygenase-1 (HO-1) in the human keratinocyte cell line HaCaT. Treatment of HaCaT cells with tin protoporphyrin IX (SnPP), a specific inhibitor of HO-1, reversed the suppressive effect of celastrol on IFN-gamma-induced protein and mRNA expression of ICAM-1. HO-1 knockdown using small interfering RNA (siRNA) led to reverse inhibition of IFN-gamma-induced up-regulation of ICAM-1 by celastrol. In addition, SnPP reversed suppression of IFN-gamma-induced promoter activity of ICAM-1 by celastrol. Furthermore, blockage of HO-1 activity by SnPP and HO-1 siRNA reversed the inhibitory effect of celastrol on IFN-gamma-induced adhesion of monocytes to keratinocytes. These results suggest that celastrol may exert anti-inflammatory responses by suppressing IFN-gamma-induced expression of ICAM-1 and subsequent monocyte adhesion via expression of HO-1 in the keratinocytes.

The grape component piceatannol induces apoptosis in DU145 human prostate cancer cells via the activation of extrinsic and intrinsic pathways.

Piceatannol (trans-3,4,3',5'-tetrahydroxystilbene) is a polyphenol that is found in grapes, red wine, Rheum undulatum, and the seeds of Euphorbia lagascae. It has been previously reported that piceatannol inhibits the proliferation of a variety of cancer cell types. In the present study, we assessed the effects of piceatannol on the growth of androgen-insensitive DU145 prostate cancer cells at concentrations of 1-10 micromol/L. Piceatannol reduced the viable numbers and increased the numbers of apoptotic DU145 cells in a dose-dependent manner. Western blot analysis revealed that piceatannol increased the protein levels of cleaved caspase-8, -9, -7, and -3 and cleaved poly(ADP-ribose) polymerase (PARP). Piceatannol increased mitochondrial membrane permeability and cytochrome c release from the mitochondria to the cytosol. Piceatannol induced an increase in the levels of truncated Bid, Bax, Bik, Bok, and Fas but caused a decrease in the levels of Mcl-1 and Bcl-xL. Caspase-8 and -9 inhibitors mitigated piceatannol-induced apoptosis. The caspase-8 inhibitor suppressed the piceatannol-induced cleavage of Bid, caspase-3, and PARP. These results indicate that piceatannol induces apoptosis via the activation of the death receptor and mitochondrial-dependent pathways in prostate cancer cells.

Blockade of oxidized LDL-triggered endothelial apoptosis by quercetin and rutin through differential signaling pathways involving JAK2.

Oxidized LDL is highly atherogenic, as it stimulates foam cell formation and promotes inflammatory and thrombotic processes. The present study elucidated whether the antioxidants quercetin and its rutinoside rutin exert antiapoptosis in endothelial cells exposed to Cu(2+)-oxidized LDL. Quercetin and rutin inhibited the oxidized LDL-induced endothelial toxicity at nontoxic doses of

Piceatannol, a stilbene present in grapes, attenuates dextran sulfate sodium-induced colitis.

Piceatannol (3,5,3',4'-tetrahydroxy-trans-stilbene; PIC) is a polyphenol found in grapes. It is known as a protein kinase inhibitor that modifies multiple cellular targets, exerting immunosuppressive and antitumorigenic activities in several cell lines. The purpose of the present work was to evaluate the anti-inflammatory effect of PIC on dextran sulfate sodium (DSS)-induced colitis. Experimental colitis was induced in BALB/c mice by dissolving 5% DSS in their drinking water for 7 days. PIC (1, 2.5, 5, or 10 mg/kg body weight) was administrated daily per oral route for 7 days. A significant blunting of weight loss and clinical signs was observed in DSS-exposed, PIC-treated mice when compared to vehicle-treated mice. This was associated with a remarkable amelioration of the disruption of the colonic architecture, a significant reduction in colonic myeloperoxidase (MPO) activity, and a decrease in production of inflammatory mediators such as nitric oxide (NO), prostaglandin (PG) E2, and pro-inflammatory cytokines. The present data indicate that further evaluation of the potential of PIC as an agent for the prevention and/or treatment of inflammatory bowel diseases in human clinical studies is warranted.