Iridoid glycosides fraction of Folium syringae leaves modulates NF-κB signal pathway and intestinal epithelial cells apoptosis in experimental colitis

Aspergillus awamori: potential antioxidant, anti-inflammatory, and anti-apoptotic activities in acetic acid-induced ulcerative colitis in rats

Ulcerative colitis (UC) is a chronic colonic inflammation with a significant health hazard. Aspergillus awamori (A. awamori) is a microorganism with various bioactive compounds with natural antioxidant and anti-inflammatory properties. The present work aimed to elucidate the protective and therapeutic effects of varying concentrations of A. awamori against acetic acid (AA)-induced ulcerative colitis (UC) in rats. Nine groups of albino male rats were established: a control negative group (G1), a control positive group (G2,AA), and preventive protocol groups (including G3A, G4A, and G5A) that received 100 mg, 50 mg, and 25 mg/kg b.w, respectively, of A. awamori orally and daily from the 1st day of the experiment and for 7 consecutive days. Then, they were subjected to one dose of AA intrarectally on day 8th. G3B, G4B, and G5B were termed as curative protocol groups that received one dose of AA on day 8th and then administered 100 mg, 50 mg, and 25 mg/kg b.w. of A. awamori, respectively, on day 9th and continued receiving these doses daily until day 16th. Rats in the AA group exhibited marked histopathological alterations of the distal colon, with an exaggeration of the DAI. In addition, a remarkable increase in oxidative stress was represented by the elevation of MDA and NO levels with a decline in SOD and GPx activities. In addition, upregulation of TNF-α, IL-6, and IL-1β mRNA expressions and downregulation of Muc2 and Nrf2 levels were detected. Unambiguously, a remarkable anti-inflammatory effect was noticed either in A. awamori prevented or treated groups expounded by reducing and regulating TNF-α, IL-6, and IL-1β with improved pathological lesion scoring. The Muc2, Nrf2, and bcl-2 gene levels were upregulated and restored also. In summary, the findings in this work reveal that A. awamori supplementation successfully alleviated the UC induced by AA, which had a better effect when administered before colitis induction.

Neohesperidin Dihydrochalcone Ameliorates Experimental Colitis via Anti-Inflammatory, Antioxidative, and Antiapoptosis Effects

Neohesperidin dihydrochalcone (NHDC) is a citrus-originated, seminatural sweetener. There is no investigation concerning the effect of NHDC on ulcerative colitis. The purpose of this study was to determine the therapeutic and protective effects of NHDC in Wistar Albino rats. NHDC was given for 7 days after or before colitis induction. The results showed that NHDC significantly reduced the interleukin-6 (IL-6), interleukin-10 (IL-10), transforming growth factor-β1 (TGF-β1), tumor necrosis factor-α (TNF-α), and interferon-γ (IFN-γ) levels. Catalase levels did not show a significant difference between the groups. NHDC provided a remarkable decrease in the expression levels of cyclooxygenase-2 (COX-2), myeloperoxidase (MPO), malondialdehyde (MDA), 8-hydroxy-2'-deoxyguanosine (8-OHdG), and nuclear factor kappa B (NF-κB). Total antioxidant status (TAS) levels were significantly elevated in NHDC treatment groups, while total oxidant status (TOS) and oxidative stress index (OSI) levels were significantly decreased. NHDC provided remarkable improvement in histological symptoms such as epithelial erosion, edema, mucosal necrosis, inflammatory cell infiltration, and hemorrhage. Also, caspase-3 expression levels were statistically decreased in NHDC treatment groups. The results indicated that NHDC might be a protection or alternative treatment for ulcerative colitis.

Inhibition of TLR4, NF-κB, and INOS pathways mediates ameliorative effect of syringic acid in experimental ulcerative colitis in rats

OBJECTIVE

Numerous therapeutics and pharmacological properties have been reported in syringic acid (SA). In this study, we aimed to evaluate effect of SA in ulcerative colitis (UC) in rats considering effect on TLR4, NF-κB, and INOS pathways.

MATERIALS AND METHODS

48 Wistar rats were randomly designated into six groups (n = 8). UC was induced via intra-rectal administration of 7% acetic acid (0.8 ml). SA at doses of 10, 25, 50 mg/kg was administrated through gavage, and dexamethasone (2 mg/kg) administrated intra-peritoneally for 5 consecutive days. The macroscopic and histopathological damages as well as expression of inflammatory and apoptotic genes along with superoxide dismutase (SOD) and catalase (CAT) activities, total antioxidant capacity (TAC), nitric oxide (NO), and malondialdehyde (MDA) levels in the colon tissue were assessed.

RESULTS

UC led to an increase in the apoptotic and inflammatory genes, NO and MDA levels as well as decrease in TAC level, and SOD and CAT activities (p < 0.05). UC also caused severe damage, edema, inflammation, and necrosis in the colon. SA significantly reduced gene expressions of INOS, TLR4, IL-6, IL-1β, NF-κB, Caspase-3, Caspase-8, and Bax. SA ameliorated negative macroscopic and histopathologic effects of UC. SA significantly reduced MDA and NO levels, and increased TAC level and CAT activity in the colon tissue in comparison to the UC rats without treatment (p < 0.05).

CONCLUSION

SA via attenuation of the TLR4-NF-κB, NF-κB-INOS-NO pathways, oxidative stress, inflammation, and apoptosis of UC in rats.

Quinic acid ameliorates ulcerative colitis in rats, through the inhibition of two TLR4-NF-κB and NF-κB-INOS-NO signaling pathways

OBJECTIVE

In this study, the therapeutic effect of quinic acid (QA), which has anti-inflammatory activity, was investigated on acetic acid-induced colitis in male Wistar rats.

METHODS

Ulcerative colitis (UC) was induced in rats by acetic acid intrarectally, and the protective effects of QA in 10, 30, 60, and 100 mg/kg doses were investigated. Rats were treated for 5 days and their colon tissues were dissected out at the end. Macroscopic and histopathological examinations were performed in colon tissues. Also, the expression of inflammatory and apoptotic genes, including TLR4, IL-1β, INOS, IL-6, TNF-α, NF-κB, Caspase-3, Caspase-8, Bax, and Bcl-2, was measured. Biochemistry indices, such as malondialdehyde (MDA) and nitrite oxide (NO) content, in addition to, total antioxidant capacity (TAC), superoxide dismutase (SOD), catalase (CAT), and enzymes activities were also assessed.

RESULTS

Colitis increased the levels of MDA and NO, and enhanced the inflammatory and apoptotic gene expressions, while reducing the SOD and CAT enzymes activity, and TAC levels in the colitis rats. Also, results showed that colitis was associated with the infiltration of inflammatory cells, epithelium damage, and edema in colon tissue. QA significantly ameliorated histopathological indices, oxidative stress, inflammation, and apoptosis in colitis rats.

CONCLUSION

QA ameliorated UC through the inhibition of two TLR4-NF-κB and NF-κB-INOS-NO signaling pathways, which results in the reduction of colitis complications, including oxidative stress, inflammation, apoptosis and histopathological injuries in rats. Therefore it can be concluded, that QA exerts its therapeutic effects through antiapoptotic, antioxidant, and anti-inflammatory properties.

Pharmacological and Clinical Efficacy of Picrorhiza kurroa and Its Secondary Metabolites: A Comprehensive Review

Traditional remedies for the treatment of various ailments are gaining popularity. Traditionally, one of the most valuable therapeutic herbs has been Picrorhiza kurroa Royle ex Benth. Traditional and folk uses of P. kurroa include chronic constipation, skin-related problems, burning sensation, chronic reoccurring fever, jaundice, heart problems, breathing, digestion, allergy, tuberculosis, blood-related problems, prediabetes and obesity, laxative, cholagogue, and liver stimulatory. Phytoconstituents such as glycosides, alkaloids, cucurbitacins, iridoids, phenolics, and terpenes in P. kurroa have shown promising pharmacological potential. In order to uncover novel compounds that may cure chronic illnesses, such as cardiovascular, diabetes, cancer, respiratory, and hepatoprotective diseases, the screening of P. kurroa is essential. This study comprehensively evaluated the ethnopharmacological efficacy, phytochemistry, pharmacological activity, dose, and toxicity of P. kurroa. This review provides comprehensive insights into this traditional medication for future research and therapeutic application. The purpose of this review article was to determine the pharmacological effects of P. kurroa on a variety of disorders. P. kurroa may be a natural alternative to the standard treatment for eradicating newly evolving diseases. This study is intended as a resource for future fundamental and clinical investigations.

Coumaric acid ameliorates experimental colitis in rats through attenuation of oxidative stress, inflammatory response and apoptosis

OBJECTIVE

Due to the high side effects of commonly used drugs and according to the pharmacological properties reported for coumaric acid (CA), this study was designed to determine the impact of CA on acetic acid-induced colitis in rats, considering its possible anti-inflammatory, antioxidant, and anti-apoptotic properties.

MATERIALS AND METHODS

Forty-eight male Wistar rats were divided into 6 equal groups (n = 8). Colitis was induced by acetic acid intrarectally. CA in three different doses (50, 100, and 150 mg/kg) was administrated for 5 days. Finally, the macroscopic and histopathological changes in the colon tissue were examined. The expression of inflammatory and apoptotic genes, including NF-κB, TNF-α, INOS, IL-1β, IL-6, TLR4, Caspase-3, Caspase-8, Bax, Bcl-2 was assessed. In addition, changes in the levels of catalase (CAT), superoxide dismutase (SOD), malondialdehyde (MDA), nitrite, and total antioxidant capacity (TAC) were measured in the colon tissue.

RESULTS

Colitis led to a decrease in TAC and the activity levels of CAT and SOD and an increase in the expression of inflammatory and apoptotic genes, MDA, and nitrite levels in the colon. Colitis was also associated with edema and severe damage to the epithelium, infiltration of inflammatory cells, and the presence of ulcers and necrosis in the colon tissue. CA significantly improved the inflammation, oxidative stress, apoptosis, and histopathological indices caused by acetic acid-induced colitis on the colon.

CONCLUSION

It is concluded that CA probably exerts its positive effects in the management of colitis, through its anti-inflammatory, antioxidant, and anti-apoptotic properties.

Probiotics-loaded nanoparticles attenuated colon inflammation, oxidative stress, and apoptosis in colitis

Promising therapy is needed for treating inflammatory bowel diseases (IBD) to overcome current treatment that inefficient and associated with unnecessary health risks. Recently, the concept of incorporating natural products into nanocarriers has been intended as a promising therapy for treating IBD via modulating their stability and bioavailability. Thus, we aimed to explore the potential alleviating effects of dietary nano-supplement combined with bacillus strains (Bacillus amyloliquefaciens; BANPs) in colitis model. Rats were orally gavaged by 5% DSS and the efficacy and mechanistic actions of BANPs were evaluated by assessing the severity of clinical signs and inflammatory and apoptosis response, histopathological and immunohistochemistry examination in colonic tissues. The severity of clinical signs was successfully alleviated and fecal Lcn-2 levels, an important colitic marker, were decreased in BANPs then free BA treated groups. In contrast, inflammatory markers overexpression IL-6, IL-1β, TNFα, COX-2, and iNOS in the colitic group were reduced more prominently in BANPs treated group, unlike free BA. The amelioration of BANPs to colon injury was also correlated with oxidative stress suppression along with restoring total antioxidant capacity. Interestingly, BANPs treatment modulated apoptotic markers as proved by downregulation of cytochrome c, and caspase-3 and upregulation of Bcl-2 and Bax than free BA. The severity of the histopathological alterations in the colon was greatly reduced in BANPs than free BA groups. Remarkably, over-expression of ki67 and IL-6 in colonic tissues were suppressed in BANPs group. These findings together highlighted the beneficial efficacy of BANPs in IBD treatment which are evidenced by colonic inflammation alleviation. Taken together, these results recommend that BANPs is a promising agent that encourages its possible therapeutic role in colitis treatment.

Natural Products Modulate Cell Apoptosis: A Promising Way for the Treatment of Ulcerative Colitis

Ulcerative colitis (UC) is a chronic inflammatory bowel disease impacting patients’ quality of life and imposing heavy societal and economic burdens. Apoptosis of intestinal epithelial cells (IECs) has been considered an early event during the onset of UC and plays a crucial role in disease development. Thus, effectively inhibiting apoptosis of IECs is of critical significance for the clinical management of UC, presenting a potential direction for the research and development of pharmacotherapeutic agents. In recent years, research on the ameliorative effects of natural products on UC through inhibiting IECs apoptosis has attracted increasing attention and made remarkable achievements in ameliorating UC. In this review, we summarized the currently available research about the anti-apoptotic effects of natural products on UC and its mechanisms involving the death-receptor mediated pathway, mitochondrial-dependent pathway, ERS-mediated pathway, MAPK-mediated pathway, NF-κB mediated pathway, P13k/Akt pathway, JAK/STAT3 pathway, and NLRP3/ASC/Caspase-1 pathway. Hopefully, this review may yield useful information about the anti-apoptotic effects of natural products on UC and their potential molecular mechanisms and provide helpful insights for further investigations.

Dual Functional Eudragit® S100/L30D-55 and PLGA Colon-Targeted Nanoparticles of Iridoid Glycoside for Improved Treatment of Induced Ulcerative Colitis

AIM

Iridoid glycosides (IG) as the major active fraction of Syringa oblata Lindl. has a proven anti-inflammatory effect for ulcerative colitis (UC). However, its current commercial formulations are hampered by low bioavailability and unable to reach inflamed colon. To overcome the limitation, dual functional IG-loaded nanoparticles (DFNPs) were prepared to increase the residence time of IG in colon. The protective mechanism of DFNPs on DSS-induced colonic injury was evaluated in rats.

MATERIALS AND METHODS

We prepared DFNPs using the oil-in-water emulsion method. PLGA was selected as sustained-release polymer, and ES100 and EL30D-55 as pH-responsive polymers. The morphology and size distribution of NPs were measured by SEM and DLS technique. To evaluate colon targeting of DFNPs, DiR, was encapsulated as a fluorescent probe into NPs. Fluorescent distribution of NPs were investigated. The therapeutic potential and in vivo transportation of NPs in gastrointestinal tract were evaluated in a colitis model.

RESULTS

SEM images and zeta data indicated the successful preparation of DFNPs. This formulation exhibited high loading capacity. Drug release results suggested DFNPs released less than 20% at the first 6 h in simulated gastric fluid (pH1.2) and simulated small intestine fluid (pH6.8). A high amount of 84.7% sustained release from NPs in simulated colonic fluid (pH7.4) was beyond 24 h. DiR-loaded NPs demonstrated a much higher colon accumulation, suggesting effective targeting due to functionalization with pH and time-dependent polymers. DFNPs could significantly ameliorate the colonic damage by reducing DAI, macroscopic score, histological damage and cell apoptosis. Our results also proved that the potent anti-inflammatory effect of DFNPs is contributed by decrease of NADPH, gene expression of COX-2 and MMP-9 and the production of TNF-α, IL-17, IL-23 and PGE2.

CONCLUSION

We confirm that DFNPs exert protective effects through inhibiting the inflammatory response, which could be developed as a potential colon-targeted system.

Protective Effect of Iridoid Glycosides of the Leaves of Syringa oblata Lindl. on Dextran Sulfate Sodium-Induced Ulcerative Colitis by Inhibition of the TLR2/4/MyD88/NF-κB Signaling Pathway

Iridoid glycoside (IG) is the major active fraction extracted from the leaves of Syringa oblata Lindl. In view of its antimicrobial and antidiarrheal potential, it could be beneficial for the treatment of ulcerative colitis (UC). In the present study, IG (20, 40, and 80 mg/kg) was administered orally for 14 days to dextran sulfate sodium- (DSS-) induced colitis rats. The anti-inflammatory effects of IG on DSS-induced UC were evaluated by comparing observations in DSS-induced colitis and drug-treated groups using disease activity index (DAI), macroscopic score, histological analysis, and apoptosis assay. To elucidate the antioxidant mechanisms of IG on NOX-dependent ROS production, the activities of 8-OHdG, NOX1, and NOX2 in DSS-induced colitis were determined. The levels of proinflammatory cytokines such as IL-2, IL-4, IL-5, IL-12p40, and IL-13 were detected. The inflammation-associated protein and mRNA expressions of TLR-2, TLR-4, MyD88, and NF-κBp65 were assessed by immunohistochemistry and real-time quantitative PCR, respectively. The results suggested that IG treatment significantly reduced DAI, macroscopic score, and histological damage compared to untreated animals (p < 0.01), whereas administration of IG remarkably attenuated the upregulation of 8-OHdG, NOX1, and NOX2 and the expression of proinflammatory cytokines such as IL-2, IL-4, IL-5, IL-12p40, and IL-13 in DSS-treated rats in a concentration-dependent manner. In addition, IG treatment could dose dependently suppress the protein and mRNA levels of TLR-2, TLR-4, MyD88, and NF-κBp65. The dose of IG that produced the most significant protective effect was 80 mg/kg. The above results demonstrate that IG exerts its inhibitory effect on cell apoptosis, oxidative stress, and proinflammatory cytokines in DSS-induced colitis through modulation of the TLR2/4/MyD88/NF-κB signaling pathway.

Notoginsenoside R1 Suppresses Inflammatory Signaling and Rescues Renal Ischemia-Reperfusion Injury in Experimental Rats

Background

Notoginsenoside R1 (NR) is a major dynamic constituent of Panax notoginseng found to possess anti-inflammatory activity against various inflammatory diseases. However, its protective effects against renal ischemia-reperfusion (I/R) injury have not been elucidated. In male Wistar rats, we induced I/R under general anesthesia by occluding the renal artery for 60 min, followed by reperfusion and right nephrectomy.

Material/Methods

Rats were randomized to 4 groups: a sham group, an I/R group, an NR-pretreated (50 mg/kg) before I/R induction group, and an NR control group. All animals were killed at 72 h after I/R induction. Blood and renal tissues were collected, and histological and basic renal function parameters were assessed. In addition, levels of various kidney markers and proinflammatory cytokines were measured using RT-PCR, ELISA, and immunohistochemistry analysis.

Results

After I/R induction, the onset of renal dysfunction was shown by the elevated levels of serum urea, creatinine levels, and histological evaluation, showing a 2-fold increase in the renal failure markers kim-1 and NGAL compared to control rats. Rats pretreated with NR before I/R induction had significantly better renal functions, with attenuated levels of oxidative markers, restored levels of inflammatory cytokines such as tumor necrosis factor-α (TNF-α), tumor growth factor-β1 (TGF-β1), INF-γ, and IL-6, and increased anti-inflammatory cytokine levels (IL-10) compared to I/R-induced rats.

Conclusions

NR suppressed I/R-induced inflammatory cytokines production by suppressing oxidative stress and kidney markers, suggesting that NR is a promising drug candidate for prevention, progression, and treatment of renal dysfunction.

Inflammation and Inflammatory Cytokine Contribute to the Initiation and Development of Ulcerative Colitis and Its Associated Cancer

Dysregulated inflammatory responses play a pivotal role in the initiation, development, and progression of tumors, as demonstrated by the association between ulcerative colitis and the increased risk of colon carcinoma. In this review, the underlying mechanisms for the initiation and development of ulcerative colitis and colitis-associated cancer are described, mainly focusing on the inflammation and inflammatory cytokine. Disruption of the intestinal mucosal barrier and bacterial invasion resulted in intestinal inflammation; and further TLR4/NF-κB stimulation in intestinal epithelial cells, inflammatory cell infiltration, and inflammatory cytokine release all confer survival advantages to or promote abnormal proliferation in susceptible cells. Importantly, the respective roles of TLR4/NF-κB, TNF-α, and IL-6 in intestinal epithelial cells and inflammatory cells are summarized in detail. A thorough understanding of these molecular mechanisms may help researchers and clinicians to explore novel approaches for the prevention and treatment of colitis-associated cancer.

Prophylactic use of probiotic chocolate modulates intestinal physiological functions in constipated rats

BACKGROUND

This study investigated the in vivo prophylactic effect of probiotic chocolate on constipation. Rats were administered chocolate containing 2.5 × 10¹⁰  CFU g^-1 of probiotics daily for 4 weeks and treated with loperamide (5 mg kg^-1 ) daily at the fourth week of treatment.

RESULTS

Probiotic chocolate treatment significantly (P < 0.05) increased the intestinal motility, colon length, fecal moisture content and number of excreted fecal pellets in constipated rats. Moreover, quantitative real-time polymerase chain reaction data and histological images also revealed that both probiotic chocolate LYC and BB12 treatments were capable of upregulating the mRNA expression levels of colonic ZO-1, occludin and AQP8, leading to the maintenance of the defensive barrier function in the constipated rats compared with the negative controls. Interestingly, these treatments also modulated gut bacterial populations by increasing the abundance levels of Lactobacillus and Bifidobacterium, as well as reducing the abundance level of Enterobacteriaceae.

CONCLUSION

The present study demonstrated that probiotic chocolate LYC and BB12 could potentially be used as alternative agents for prophylactic constipation. © 2018 Society of Chemical Industry.

Protective effects of Paederia scandens extract on rheumatoid arthritis mouse model by modulating gut microbiota

ETHNOPHARMACOLOGICAL RELEVANCE

Paederia scandens (Lour.) Merr. (P. scandens) has been traditionally used to treat the pain of rheumatism.

AIM OF THE STUDY

The purpose of this study was to investigate the possible influences of P. scandens on the progression of rheumatoid arthritis (RA), inflammatory responses and gut bacterial communities in RA mouse model.

MATERIALS AND METHODS

collagen-induced arthritis (CIA) mice were orally administered with P. scandens extract (PSE) for 24 days. Then, pro-inflammatory cytokine levels in the serum were measured, and gut microbiota was examined with Illumina HiSeq.

RESULTS

Compared with the vehicle group, PSE significantly inhibited paw swelling and reduced arthritis score. Histological examination of ankle soft tissue of demonstrated PSE effectively inhibited the tissue fibrosis and inflammatory cell infiltration. The increased serum levels of TNF-α, IL-1β, IL-6, IL-7, and IL-23 in RA mice were significantly suppressed by PSE. Moreover, PSE treatment help restore gut microbial ecosystem altered in RA mice including decreasing relative abundance of inflammatory related microorganisms, Desulfovibrio, Mucispirillum, Helicobacter, and Lachnospiraceae.

CONCLUSION

These results suggest that PSE has therapeutic effects in RA mice with CIA, showing the potential as anti-arthritis reagent.

The Bisindole Alkaloid Caulerpin, from Seaweeds of the Genus Caulerpa, Attenuated Colon Damage in Murine Colitis Model

Caulerpin (CLP), an alkaloid from algae of the genus Caulerpa, has shown anti-inflammatory activity. Therefore, this study aimed to analyze the effect of CLP in the murine model of peritonitis and ulcerative colitis. Firstly, the mice were submitted to peritonitis to evaluate which dose of CLP (40, 4, or 0.4 mg/kg) could decrease the inflammatory infiltration in the peritoneum. The most effective doses were 40 and 4 mg/kg. Then, C57BL/6 mice were submitted to colitis development with 3% dextran sulfate sodium (DSS) and treated with CLP at doses of 40 and 4 mg/kg. The disease development was analyzed through the disease activity index (DAI); furthermore, colonic tissue samples were submitted to histological analysis, NFκB determination, and in vitro culture for cytokines assay. Therefore, CLP at 4 mg/kg presented the best results, triggering improvement of DAI and attenuating the colon shortening and damage. This dose was able to reduce the TNF-α, IFN-γ, IL-6, IL-17, and NFκB p65 levels, and increased the levels of IL-10 in the colon tissue. Thus, CLP mice treatment at a dose of 4 mg/kg showed promising results in ameliorating the damage observed in the ulcerative colitis.

Anti-Inflammatory Effects of Fargesin on Chemically Induced Inflammatory Bowel Disease in Mice

Fargesin is a bioactive lignan from Flos Magnoliae, an herb widely used in the treatment of allergic rhinitis, sinusitis, and headache in Asia. We sought to investigate whether fargesin ameliorates experimental inflammatory bowel disease (IBD) in mice. Oral administration of fargesin significantly attenuated the symptoms of dextran sulfate sodium (DSS)-induced colitis in mice by decreasing the inflammatory infiltration and myeloperoxidase (MPO) activity, reducing tumor necrosis factor (TNF)-α secretion, and inhibiting nitric oxide (NO) production in colitis mice. The degradation of inhibitory κBα (IκBα), phosphorylation of p65, and mRNA expression of nuclear factor κB (NF-κB) target genes were inhibited by fargesin treatment in the colon of the colitis mice. In vitro, fargesin blocked the nuclear translocation of p-p65, downregulated the protein levels of inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2), and dose-dependently inhibited the activity of NF-κB-luciferase in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages. Taken together, for the first time, the current study demonstrated the anti-inflammatory effects of fargesin on chemically induced IBD might be associated with NF-κB signaling suppression. The findings may contribute to the development of therapies for human IBD by using fargesin or its derivatives.

Olive oil polyphenols reduce oxysterols -induced redox imbalance and pro-inflammatory response in intestinal cells

Dietary habits may strongly influence intestinal homeostasis. Oxysterols, the oxidized products of cholesterol present in cholesterol-containing foodstuffs, have been shown to exert pro-oxidant and pro-inflammatory effects, altering intestinal epithelial layer and thus contributing to the pathogenesis of human inflammatory bowel diseases and colon cancer. Extra virgin olive oil polyphenols possess antioxidant and anti-inflammatory properties, and concentrate in the intestinal lumen, where may help in preventing intestinal diseases. In the present study we evaluated the ability of an extra virgin olive oil phenolic extract to counteract the pro-oxidant and pro-inflammatory action of a representative mixture of dietary oxysterols in the human colon adenocarcinoma cell line (Caco-2) undergoing full differentiation into enterocyte-like cells. Oxysterols treatment significantly altered differentiated Caco-2 cells redox status, leading to oxidant species production and a decrease of GSH levels, after 1 h exposure, followed by an increase of cytokines production, IL-6 and IL-8, after 24 h. Oxysterol cell treatment also induced after 48 h an increase of NO release, due to the induction of iNOS. Pretreatment with the phenolic extract counteracted oxysterols effects, at least in part by modulating one of the main pathways activated in the cellular response to the action of oxysterols, the MAPK-NF-kB pathway. We demonstrated the ability of the phenolic extract to directly modulate p38 and JNK1/2 phosphorylation and activation of NF-kB, following its inhibitor IkB phosphorylation. The phenolic extract also inhibited iNOS induction, keeping NO concentration at the control level. Our results suggest a protective effect at intestinal level of extra virgin olive oil polyphenols, able to prevent or limit redox unbalance and the onset and progression of chronic intestinal inflammation.

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Dietary oxysterols exerted pro-oxidant and pro-inflammatory effects in differentiated Caco-2 cells.

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H₂O₂ production, GSH decrease, IL-6 and IL-8 release were detected.

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NO release due to iNOS induction was higher than controls in oxysterols treated cells.

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Olive oil phenolic extract efficiently counteracted oxysterols effects.

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Phenolic extract directly modulated p38 and JNK MAPK/NF-κB signaling axis.

Iridoid glycosides fraction from Picrorhiza kurroa attenuates cyclophosphamide-induced renal toxicity and peripheral neuropathy via PPAR-γ mediated inhibition of inflammation and apoptosis

BACKGROUND

Picrorhiza kurroa Royle (Scrophulariaceae) is an important medicinal herb being widely used in variety of ailments.

PURPOSE

The present study was envisaged to evaluate the effects of iridoid glycosides enriched fraction (IGs) from Picrorhiza kurroa rhizome against cyclophosphamide (CP) -induced renal toxicity and peripheral neuropathy.

METHODS

Mice in different groups were pretreated with 25, 50 and 100 mg/kg; p.o. doses of IGs for 21 days, followed by cyclophosphamide intoxication for consecutive two days. Further, to identify the putative role of PPAR-γ receptors for the protective effect of IGs, an additional group of mice were pretreated with PPAR-γ antagonist BADGE (5 mg/kg; i.p.) followed by IGs (100 mg/kg; p.o.) for 21 days before CP intoxication.

RESULTS

IGs pretreatment decreased the hyperalgesic responses toward acetone and heat in acetone drop and tail immersion tests. The abolition of intramyelin odema, cytoplasmic vacuolization and axonal degeneration of sciatic nerve were observed in IGs pretreated mice in a dose-dependent manner. IGs treatment also attenuated the altered serum biochemical markers for renal injury. Furthermore, the treatment prevented renal tubular swelling, granular degeneration and glomerular damage. The levels of IL-1β and TNFα in different group revealed the anti-inflammatory effect of IGs, which was further confirmed by improvement in altered expressions of NF-kB in kidney and sciatic serve. Bax/Bcl-2 expressions and caspase 3/9 activity in renal tissues showed the anti-apoptotic effect of IGs. IGs pretreatment also improved the PPAR-γ expression in the kidney tissues. All the observed protective effects of IGs were suppressed after pretreatment with BADGE.

CONCLUSION

Present study concludes that IGs from Picrorhiza kurroa attenuates CP-induced renal toxicity and peripheral neuropathy via PPAR-γ -mediated pathways.

Patchouli alcohol ameliorates dextran sodium sulfate-induced experimental colitis and suppresses tryptophan catabolism

Despite the increased morbidity of ulcerative colitis (UC) in recent years, available treatments remain unsatisfactory. Pogostemon cablin has been widely applied to treat a variety of gastrointestinal disorders in clinic for centuries, in which patchouli alcohol (PA, C₁₅H₂₆O) has been identified as the major active component. This study attempted to determine the bioactivity of PA on dextran sulfate sodium (DSS)-induced mice colitis and clarify the mechanism of action. Acute colitis was induced in mice by 3% DSS for 7 days. The mice were then given PA (10, 20 and 40mg/kg) or sulfasalazine (SASP, 200mg/kg) as positive control via oral administration for 7 days. At the end of study, animals were sacrificed and samples were collected for pathological and other analysis. In addition, a metabolite profiling and a targeted metabolite analysis, based on the Ultra-Performance Liquid Chromatography coupled with mass spectrometry (UPLC-MS) approach, were performed to characterize the metabolic changes in plasma. The results revealed that PA significantly reduced the disease activity index (DAI) and ameliorated the colonic injury of DSS mice. The levels of colonic MPO and cytokines involving TNF-α, IFN-γ, IL-1β, IL-6, IL-4 and IL-10 also declined. Furthermore, PA improved the intestinal epithelial barrier by enhancing the level of colonic expression of the tight junction (TJ) proteins, for instance ZO-1, ZO-2, claudin-1 and occludin, and by elevating the levels of mucin-1 and mucin-2 mRNA. The study also demonstrated that PA inhibited the DSS-induced cell death signaling by modulating the apoptosis related Bax and Bcl-2 proteins and down-regulating the necroptosis related RIP3 and MLKL proteins. By comparison, up-regulation of IDO-1 and TPH-1 protein expression in DSS group was suppressed by PA, which was in line with the declined levels of kynurenine (Kyn) and 5-hydroxytryptophan (5-HTP) in plasma. The therapeutic effect of PA was evidently reduced when Kyn was given to mice. In summary, the study successfully demonstrated that PA ameliorated DSS-induced mice acute colitis by suppressing inflammation, maintaining the integrity of intestinal epithelial barrier, inhibiting cell death signaling, and suppressing tryptophan catabolism. The results provided valuable information and guidance for using PA in treatment of UC.

Chemical profiles and pharmacological activities of Chang-Kang-Fang, a multi-herb Chinese medicinal formula, for treating irritable bowel syndrome

ETHNOPHARMACOLOGICAL RELEVANCE

Chang-Kang-Fang formula (CKF), a multi-herb traditional Chinese medicinal formula, has been clinically used for treatment of irritable bowel syndrome (IBS). The mechanisms of CKF for treating IBS and the components that are responsible for the activities were still unknown.

AIM OF THE STUDY

To investigate the chemical profiles and effects of CKF on IBS model.

MATERIALS AND METHODS

The chemical profiles of CKF were investigated by ultra performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UHPLC-Q/TOF-MS/MS). On colon irritation induced rat neonates IBS model, the influence of CKF on neuropeptides, including substance P (SP), calcitonin gene-related peptide (CGRP), vasoactive intestinal polypeptide (VIP) and 5-hydroxytryptamine (5-HT), were measured by ELISA, and the effect on intestinal sensitivity was assessed based on the abdominal withdrawal reflex (AWR) scores. In addition, the activities of CKF against acetic acid-induced nociceptive responses and prostigmin methylsulfate triggered intestinal propulsion in mice were also evaluated.

RESULTS

80 components were identified or tentatively assigned from CKF, including 11 alkaloids, 20 flavanoids, 4 monoterpenoids, 9 iridoid glycoside, 9 phenylethanoid glycosides, 10 chromones, 7 organic acid, 3 coumarins, 2 triterpene and 5 other compounds. On IBS rat model, CKF was observed to reduce AWR scores and levels of SP, CGRP, VIP and 5-HT. Moreover, CKF reduced the acetic acid-induced writhing scores at all dosages and reduced the intestinal propulsion ration at dosage of 7.5 and 15.0g/kg/d.

CONCLUSIONS

CKF could alleviate the symptoms of IBS by modulating the brain-gut axis through increasing the production of neuropeptides such as CGRP, VIP, 5-HT and SP, releasing pain and reversing disorders of intestinal propulsion. Berberine, paeoniflorin, acteoside, flavonoids and chromones may be responsible for the multi-bioactivities of CKF.

Inhibitory Activities of Phenolic Compounds Isolated from Adina rubella Leaves Against 5α-Reductase Associated with Benign Prostatic Hypertrophy

Adina rubella Hance (AR), a plant native to Korea, has been used as traditional medicine for dysentery, eczema, intoxication, and external hemorrhages. Previous phytochemical studies of AR have reported several components, including terpenoids, phenolics, and alkaloids. The current study evaluated the anti-oxidative and anti-inflammatory activities and 5α-reductase inhibition of isolated compounds of AR leaves to find a potential therapeutic agent for benign prostatic hypertrophy (BPH). Repeated chromatographic isolation of an 80% acetone extract of AR leaves yielded seven phenolic compounds: caffeic acid (1), chlorogenic acid (2), methyl chlorogenate (3), quercetin-3-rutinoside (4), kaempferol-3-O-α-l-rhamnopyranosyl-(1→6)-β-d-glucopyranoside (5), hyperoside (6), and grandifloroside (7). Compound 7 is a novel compound in AR. Caffeoyl derivatives 1–3 and 7 showed good anti-oxidative activities. In particular, caffeic acid (1) and grandifloroside (7) showed potent anti-inflammatory activities, and 7 also exhibited potent inhibitory activity against TNF-α and 5α-reductase. Our results show that the extract and grandifloroside (7) from leaves of AR might be developed as a source of potent anti-oxidative and anti-inflammatory agents and therapeutic agent for BPH.

Si Shen Wan Regulates Phospholipase Cγ-1 and PI3K/Akt Signal in Colonic Mucosa from Rats with Colitis

The present study explored the feasible pathway of Si Shen Wan (SSW) in inhibiting apoptosis of intestinal epithelial cells (IECs) by observing activation of phospholipase Cγ-1 (PLC-γ1) and PI3K/Akt signal in colonic mucosa from rats with colitis. Experimental colitis was induced by 2,4,6-trinitrobenzene sulfonic acid (TNBS) in the Sprague-Dawley rats. After SSW was administrated for 7 days after TNBS infusion, western blot showed an increment in levels of PI3K, p-Akt, and IL-23 and a decrement in levels of PLC-γ1 and HSP70 in colonic mucosal injury induced by TNBS. Meanwhile, assessments by ELISA revealed an increment in concentrations of IL-2, IL-6, and IL-17 and a reduction in level of TGF-β after TNBS challenge. Impressively, treatment with SSW for 7 days significantly attenuated the expressions of PI3K and p-Akt and the secretion of IL-2, IL-6, IL-17, and IL-23 and promoted the activation of PLC-γ1, HSP70, and TGF-β. Our previous studies had demonstrated that SSW restored colonic mucosal ulcers by inhibiting apoptosis of IECs. The present study demonstrated that the effect of SSW on inhibiting apoptosis of IECs was realized probably by activation of PLC-γ1 and suppression of PI3K/Akt signal pathway.

Phytochemical and pharmacological progress on the genus Syringa

Genus Syringa, belonging to the Oleaceae family, consists of more than 40 plant species worldwide, of which 22 species, including 18 endemic species, are found in China. Most Syringa plants are used in making ornaments and traditional medicines, whereas some are employed for construction or economic use. Previous studies have shown that extracts of Syringa plants mainly contain iridoids, lignans, and phenylethanoids that have antitumor, antihypertensive, anti-oxidant, and anti-inflammatory activities. This study reviews phytochemical and pharmacological progress on Syringa in the recent 20 years and discusses the future research prospects to provide a reference in further promotion and application of the genus.

Graphical Abstract

Notoginsenoside R1 attenuates experimental inflammatory bowel disease via pregnane X receptor activation

Notoginsenoside R1 (R1) is the main bioactive component in Panax notoginseng, an old herb medicine widely used in Asian countries in the treatment of microcirculatory diseases. However, little is known about the effect of R1 on inflammatory bowel disease (IBD). The present study demonstrated that R1 alleviated the severity of dextran sulfate sodium-induced colitis in mice by decreasing the activity of myeloperoxidase, the production of cytokines, the expression of proinflammatory genes, and the phosphorylation of IκB kinase, IκBα, and p65 in the colon. Further studies indicated that R1 dose-dependently activated human/mouse pregnane X receptor (PXR), a known target for decreasing inflammation in IBD, and upregulated the expression of genes involved in xenobiotic metabolism in colorectal cells and the colon. Ligand pocket-filling mutant (S247W/C284W or S247W/C284W/S208W) of the human PXR abrogated the effect of R1 on PXR activation. Time-resolved fluorescence resonance energy transfer PXR competitive binding assay confirmed R1 (ligand) binding affinity. In addition, PXR overexpression inhibited nuclear factor-κB (NF-κB)-luciferase activity, which was potentiated by R1 treatment. PXR knockdown by small interfering RNA demonstrated the necessity of PXR in R1-induced upregulation of the expression of xenobiotic-metabolizing enzymes and downregulation of NF-κB activity. Finally, the anti-inflammatory effect of R1 was confirmed in trinitrobenzene sulfonic acid-induced colitis in mice. These findings suggest that R1 attenuates experimental IBD possibly via the activation of intestinal PXR signaling.

High concentrate diet induced mucosal injuries by enhancing epithelial apoptosis and inflammatory response in the hindgut of goats

PURPOSE

It is widely accepted that lipopolysaccharide and volatile fatty acids (VFA) accumulate in the digestive tract of ruminants fed diets containing high portions of grain. Compared to the ruminal epithelium, the hindgut epithelium is composed of a monolayer structure that is more "leaky" for lipopolysaccharide and susceptible to organic acid-induced damage. The aim of this study was to investigate changes in epithelial structure, apoptosis and inflammatory response in the hindgut of goats fed a high-concentrate diet for 6 weeks.

EXPERIMENTAL DESIGN

Eight local Chinese goats with rumen cannulas were randomly assigned to two groups: one group was fed a high-concentrate diet (65% concentrate of dry matter, HC) and the other group was fed a low-concentrate diet (35% concentrate of dry matter, LC) for 6 wks. Ruminal fluid, plasma, and hindgut mucosa tissues were collected. Histological techniques, real-time PCR and western blotting were used to evaluate the tissues structure, cell apoptosis and local inflammation in the hindguts.

RESULTS

Feeding HC diet for 6 wks resulted in a significant decrease of ruminal pH (p<0.01), and ruminal lipopolysaccharide concentrations were significantly increased in HC goats (p<0.05). Obvious damage was observed to mucosal epithelium of the hindgut and the intercellular tight junctions in HC, but not in LC, goats. The expression of MyD88 and caspase-8 mRNA was increased in colonic epithelium of HC goats compared to LC (p<0.05), and the expression of TLR-4 and caspase-3 showed a tendency to increase. In the cecum, interleukin-1β mRNA expression was decreased (p<0.05), and caspase-3 showed a potential increase (p = 0.07) in HC goats. The level of NF-κB protein was increased in colonic epithelium of HC goats. Caspase-3 activity was elevated in both colon and cecum, whereas caspase-8 activity was statistically increased only in colon.

CONCLUSIONS

Feeding a high-concentrate diet to goats for 6 wks led to hindgut mucosal injuries via activating epithelial cells apoptosis and local inflammatory response.

Telmisartan attenuates colon inflammation, oxidative perturbations and apoptosis in a rat model of experimental inflammatory bowel disease

Accumulating evidence has indicated the implication of angiotensin II in the pathogenesis of inflammatory bowel diseases (IBD) via its proinflammatory features. Telmisartan (TLM) is an angiotensin II receptor antagonist with marked anti-inflammatory and antioxidant actions that mediated its cardio-, reno- and hepatoprotective actions. However, its impact on IBD has not been previously explored. Thus, we aimed to investigate the potential alleviating effects of TLM in tri-nitrobenezene sulphonic acid (TNBS)-induced colitis in rats. Pretreatment with TLM (10 mg/kg p.o.) attenuated the severity of colitis as evidenced by decrease of disease activity index (DAI), colon weight/length ratio, macroscopic damage, histopathological findings and leukocyte migration. TLM suppressed the inflammatory response via attenuation of tumor necrosis factor-α (TNF-α), prostaglandin E₂ (PGE₂) and myeloperoxidase (MPO) activity as a marker of neutrophil infiltration besides restoration of interleukin-10 (IL-10). TLM also suppressed mRNA and protein expression of nuclear factor kappa B (NF-κB) p65 and mRNA of cyclo-oxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) proinflammatory genes with concomitant upregulation of PPAR-γ. The alleviation of TLM to colon injury was also associated with inhibition of oxidative stress as evidenced by suppression of lipid peroxides and nitric oxide (NO) besides boosting glutathione (GSH), total anti-oxidant capacity (TAC) and the activities of superoxide dismutase (SOD) and glutathione peroxidase (GPx). With respect to apoptosis, TLM downregulated the increased mRNA, protein expression and activity of caspase-3. It also suppressed the elevation of cytochrome c and Bax mRNA besides the upregulation of Bcl-2. Together, these findings highlight evidences for the beneficial effects of TLM in IBD which are mediated through modulation of colonic inflammation, oxidative stress and apoptosis.

Review article: the role of oxidative stress in pathogenesis and treatment of inflammatory bowel diseases

In this review, we focus on the role of oxidative stress in the aetiology of inflammatory bowel diseases (IBD) and colitis-associated colorectal cancer and discuss free radicals and free radical-stimulated pathways as pharmacological targets for anti-IBD drugs. We also suggest novel anti-oxidative agents, which may become effective and less-toxic alternatives in IBD and colitis-associated colorectal cancer treatment. A Medline search was performed to identify relevant bibliography using search terms including: ‘free radicals,’ ‘antioxidants,’ ‘oxidative stress,’ ‘colon cancer,’ ‘ulcerative colitis,’ ‘Crohn’s disease,’ ‘inflammatory bowel disease.’ Several therapeutics commonly used in IBD treatment, among which are immunosuppressants, corticosteroids and anti-TNF-α antibodies, could also affect the IBD progression by interfering with cellular oxidative stress and cytokine production. Experimental data shows that these drugs may effectively scavenge free radicals, increase anti-oxidative capacity of cells, influence multiple signalling pathways, e.g. MAPK and NF-kB, and inhibit pro-oxidative enzyme and cytokine concentration. However, their anti-oxidative and anti-inflammatory effectiveness still needs further investigation. A highly specific antioxidative activity may be important for the clinical treatment and relapse of IBD. In the future, a combination of currently used pharmaceutics, together with natural and synthetic anti-oxidative compounds, like lipoic acid or curcumine, could be taken into account in the design of novel anti-IBD therapies.

Inhibitory effect of the gallotannin corilagin on dextran sulfate sodium-induced murine ulcerative colitis

The therapeutic effect of corilagin (1) was evaluated in an acute colitis model induced by dextran sulfate sodium (DSS) in mice, and the mechanism of action was investigated in this study. Animals were challenged with 2% DSS drinking water for 5 consecutive days and then intraperitoneally treated with 1 (7.5, 15, and 30 mg/kg) daily for 7 days. It was found that 1 significantly decreased the disease activity index, inhibited the shortening of colon length, reduced colon tissue damage, and suppressed myeloperoxidase activity. Moreover, 1 greatly suppressed the secretion of TNF-α, IL-6, and IL-1β, inhibited the degradation of IκB α, and down-regulated expression of cleaved caspase-3 and cleaved caspase-9 in colon tissues of DSS-treated mice. These findings demonstrated that 1 exerts a protective effect on DSS-induced colitis, and its underlying mechanisms are associated with inhibition of the NF-κB pathway that mitigates colon inflammatory responses and apoptosis of intestinal epithelial cells.

Treatment with diammonium glycyrrhizinate down-regulates M30 expression in ulcerative colitis in rats

AIM: To assess the therapeutic effect of diammonium glycyrrhizinate (DG) on 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced ulcerative colitis in rats and to explore the underlying mechanisms by detecting the expression of M30 and Fas/FasL.

METHODS: Thirty Wistar rats were equally randomized into a normal control group, a model group and a DG group. Ulcerative colitis was induced in the DG group and model group with TNBS by enema. After ten days, all rats were killed. Disease activity index (DAI), colon macroscopic damage score (CMDS) and histological damage score were calculated, and the expression of M30 and Fas/FasL in the colonic mucosa was detected by immunohistochemistry.

RESULTS: Compared to normal controls, the DAI, CMDS and histological damage score significantly increased in model rats (7.06 ± 0.80 vs 0.32 ± 0.14; 6.03 ± 0.61 vs 0.19 ± 0.16; 5.84 ± 0.53 vs 0.22 ± 0.11, P < 0.01). Compared to the model group, the above parameters were significantly improved in the DG group (3.33 ± 0.27 vs 7.06 ± 0.80; 3.29 ± 0.36 vs 6.03 ± 0.61; 2.98 ± 0.24 vs 5.84 ± 0.53, P < 0.05). Compared to the normal control group, the expression of M30 and Fas/FasL was up-regulated in the model group and DG group (5.76 ± 0.66 vs 0.42 ± 0.18; 26.62 ± 4.20 vs 10.81 ± 2.20; 17.11 ± 3.12 vs 6.02 ± 1.02, P < 0.01). Compared to the model group, the expression of M30 and Fas/FasL was remarkably decreased in the DG group (2.24 ± 0.48 vs 5.76 ± 0.66; 17.23 ± 3.20 vs 26.62 ± 4.20; 11.02 ± 2.12 vs 17.11 ± 3.12, P < 0.05).

CONCLUSION: Treatment with DG could reduce inflammatory injury in rats with experimental ulcerative colitis possibly by reducing the expression Fas/FasL and inhibiting apoptosis of cells in the colonic mucosa.

Anti-inflammatory effects of Lacto-Wolfberry in a mouse model of experimental colitis

AIM: To investigate the anti-inflammatory properties of Lacto-Wolfberry (LWB), both in vitro and using a mouse model of experimental colitis.

METHODS: The effects of LWB on lipopolysaccharide (LPS)-induced reactive oxygen species (ROS) and interleukin (IL)-6 secretion were assessed in a murine macrophage cell line. in vitro assessment also included characterizing the effects of LWB on the activation of NF-E2 related 2 pathway and inhibition of tumor necrosis factor-α (TNF-α)-induced nuclear factor-κB (NF-κB) activation, utilizing reporter cell lines. Following the in vitro assessment, the anti-inflammatory efficacy of an oral intervention with LWB was tested in vivo using a preclinical model of intestinal inflammation. Multiple outcomes including body weight, intestinal histology, colonic cytokine levels and anti-oxidative measures were investigated.

RESULTS: LWB reduced the LPS-mediated induction of ROS production [+LPS vs 1% LWB + LPS, 1590 ± 188.5 relative luminescence units (RLU) vs 389 ± 5.9 RLU, P < 0.001]. LWB was more effective than wolfberry alone in reducing LPS-induced IL-6 secretion in vitro (wolfberry vs 0.5% LWB, 15% ± 7.8% vs 64% ± 5%, P < 0.001). In addition, LWB increased reporter gene expression via the anti-oxidant response element activation (wolfberry vs LWB, 73% ± 6.9% vs 148% ± 28.3%, P < 0.001) and inhibited the TNF-α-induced activation of the NF-κB pathway (milk vs LWB, 10% ± 6.7% vs 35% ± 3.3%, P < 0.05). Furthermore, oral supplementation with LWB resulted in a reduction of macroscopic (-LWB vs +LWB, 5.39 ± 0.61 vs 3.66 ± 0.59, P = 0.0445) and histological scores (-LWB vs +LWB, 5.44 ± 0.32 vs 3.66 ± 0.59, P = 0.0087) in colitic mice. These effects were associated with a significant decrease in levels of inflammatory cytokines such as IL-1β (-LWB vs +LWB, 570 ± 245 μg/L vs 89 ± 38 μg/L, P = 0.0106), keratinocyte-derived chemokine/growth regulated protein-α (-LWB vs +LWB, 184 ± 49 μg/L vs 75 ± 20 μg/L, P = 0.0244), IL-6 (-LWB vs +LWB, 318 ± 99 μg/L vs 117 ± 18 μg/L, P = 0.0315) and other pro-inflammatory proteins such as cyclooxygenase-2 (-LWB vs +LWB, 0.95 ± 0.12 AU vs 0.36 ± 0.11 AU, P = 0.0036) and phosphorylated signal transducer and activator of transcription-3 (-LWB vs +LWB, 0.51 ± 0.15 AU vs 0.1 ± 0.04 AU, P = 0.057). Moreover, antioxidant biomarkers, including expression of gene encoding for the glutathione peroxidase, in the colon and the plasma anti-oxidant capacity were significantly increased by supplementation with LWB (-LWB vs +LWB, 1.2 ± 0.21 mmol/L vs 2.1 ± 0.19 mmol/L, P = 0.0095).

CONCLUSION: These results demonstrate the anti-inflammatory properties of LWB and suggest that the underlying mechanism is at least in part due to NF-κB inhibition and improved anti-oxidative capacity.

A novel in vivo siRNA delivery system specifically targeting liver cells for protection of ConA-induced fulminant hepatitis

Background

Fulminant hepatitis progresses to acute liver failure (ALF) when the extent of hepatocyte death exceeds the liver's regenerative capacity. Although small interfering RNA (siRNA) appears promising in animal models of hepatitis, the approach is limited by drawbacks associated with systemic administration of siRNA. The aim of this study is to develop a hepatocyte-specific delivery system of siRNA for treatment of fulminant hepatitis.

Methodology/Principal Findings

Galactose-conjugated liposome nano-particles (Gal-LipoNP) bearing siRNA was prepared, and the particle size and zeta potential of Gal-LipoNP/siRNA complexes were measured. The distribution, cytotoxicity and gene silence efficiency were studied in vivo in a concanavalin A (ConA)-induced hepatitis model. C57BL/6 mice were treated with Gal-LipoNP Fas siRNA by i.v. injection 72 h before ConA challenge, and hepatocyte injury was evaluated using serum alanine transferase (ALT) and aspartate transaminase (AST) levels, as well as liver histopathology and TUNEL-positive hepatocytes. The galactose-ligated liposomes were capable of encapsulating >96% siRNA and exhibited a higher stability than naked siRNA in plasma. Hepatocyte-specific targeting was confirmed by in vivo delivery experiment, in which the majority of Gal-LipoNP-siRNA evaded nuclease digestion and accumulated in the liver as soon as 6 h after administration. In vivo gene silencing was significant in the liver after treatment of Gal-Lipo-siRNA. In the ConA-induced hepatitis model, serum levels of ALT and AST were significantly reduced in mice treated with Gal-lipoNP-siRNA as compared with control mice. Additionally, tissue histopathology and apoptosis showed an overall reduction of injury in the Gal-LipoNP siRNA-treated mice.

Conclusions/Significance

This study is the first to our knowledge to demonstrate reduction of hepatic injury by liver-specific induction of RNA interference using Gal-LipoNP Fas siRNA, highlighting a novel RNAi-based therapeutic potential in many liver diseases.

Augmented activity of the pelvic nerve afferent mediated by TRP channels in dextran sulfate sodium (DSS)-induced colitis of rats

Enteritis has been recognized as a major symptom in domestic animals and human patients suffering from feed and food poisonings. The aim of the present study was to clarify the excitatory mechanism of the pelvic nerve afferent which may influence the occurrence of enteritis in response to nociceptive chemical stimuli of the colon in normal and abnormal rats with colitis induced by dextran sulfate sodium (DSS). The pelvic nerve afferent activity was markedly increased by colonic instillation of solution (0.5 ml) of acetic acid (5-25%) and capsaicin (100 μg/ml). The nerve activity was augmented by colonic instillation of capsaicin to a greater extent in rats with DSS-induced colitis than in normal control rats. This augmented activity by capsaicin was more prominent at one day (DSS-1) than at 8 day (DSS-8) after the administration of DSS. The increased nerve activity caused by capsaicin in DSS-1 and DSS-8 was significantly inhibited by pretreatment with ruthenium red, which is a nonselective inhibitor of TRP channels of unmyelinated C-fibers (nociceptors). In conclusion, it was elucidated that the nociceptive function of the pelvic nerve was largely elevated at one day after DSS-induced colitis and such increased function was mostly mediated by TRP channels.

Anti-inflammatory iridoids of botanical origin

Inflammation is a manifestation of a wide range of disorders which include; arthritis, atherosclerosis, Alzheimer's disease, inflammatory bowel syndrome, physical injury and infection amongst many others. Common treatment modalities are usually nonsteroidal anti-inflammatory drugs (NSAIDs) such as aspirin, paracetamol, indomethacin and ibuprofen as well as corticosteroids such as prednisone. These however, may be associated with a host of side effects due to non-selectivity for cyclooxygenase (COX) enzymes involved in inflammation and those with selectivity may be highly priced. Thus, there is a continuing search for safe and effective antiinflammatory molecules from natural sources. Research has confirmed that iridoids exhibit promising anti-inflammatory activity which may be beneficial in the treatment of inflammation. Iridoids are secondary metabolites present in various plants, especially in species belonging to the Apocynaceae, Lamiaceae, Loganiaceae, Rubiaceae, Scrophulariaceae and Verbenaceae families. Many of these ethnobotanicals have an illustrious history of traditional use alluding to their use to treat inflammation. Although iridoids exhibit a wide range of pharmacological activities such as cardiovascular, hepatoprotection, hypoglycaemic, antimutagenic, antispasmodic, anti-tumour, antiviral, immunomodulation and purgative effects this review will acutely focus on their anti-inflammatory properties. The paper aims to present a summary for the most prominent iridoid-containing plants for which anti-inflammatory activity has been demonstrated in vitro and / or in vivo.