Protective effects of 3,4-oxo-isopropylidene-shikimic acid on experimental colitis induced by trinitrobenzenesulfonic acid in rats

Harnessing nature's pharmacy: investigating natural compounds as novel therapeutics for ulcerative colitis

Backgrounds

Ulcerative colitis (UC) is a form of chronic inflammatory bowel disease, and UC diagnosis rates continue to rise throughout the globe. The research and development of new drugs for the treatment of UC are urgent, and natural compounds are an important source. However, there is a lack of systematic summarization of natural compounds and their mechanisms for the treatment of UC.

Methods

We reviewed the literature in the databases below from their inception until July 2023: Web of Science, PubMed, China National Knowledge Infrastructure, and Wanfang Data, to obtain information on the relationship between natural compounds and UC.

Results

The results showed that 279 natural compounds treat UC through four main mechanisms, including regulating gut microbiota and metabolites (Mechanism I), protecting the intestinal mucosal barrier (Mechanism II), regulating intestinal mucosal immune response (Mechanism III), as well as regulating other mechanisms (Mechanism Ⅳ) such as cellular autophagy modulation and ferroptosis inhibition. Of these, Mechanism III is regulated by all natural compounds. The 279 natural compounds, including 62 terpenoids, 57 alkaloids, 52 flavonoids, 26 phenols, 19 phenylpropanoids, 9 steroids, 9 saponins, 8 quinonoids, 6 vitamins, and 31 others, can effectively ameliorate UC. Of these, terpenoids, alkaloids, and flavonoids have the greatest potential for treating UC. It is noteworthy to highlight that a total of 54 natural compounds exhibit their therapeutic effects by modulating Mechanisms I, II, and III.

Conclusion

This review serves as a comprehensive resource for the pharmaceutical industry, researchers, and clinicians seeking novel therapeutic approaches to combat UC. Harnessing the therapeutic potential of these natural compounds may significantly contribute to the improvement of the quality of life of patients with UC and promotion of disease-modifying therapies in the future.

Shikimic acid recovers diarrhea and its complications in SD rats fed lactose diet to induce diarrhea

BACKGROUND

Diarrhea is the increase of excretion of human water content and an imbalance in the physiologic processes of the small and large intestine while shikimic acid is an important biochemical metabolite in plants. This study aims to study the anti-diarrheal activity of shikimic acid through restoring kidney function, antioxidant activity, inflammatory markers, sodium/potassium-ATPase activity, apoptosis genes, and histology of the kidney in SD rats fed lactose diet to induce diarrhea.

RESULTS

Thirty-six male SD rats (150 ± 10 g, 12 weeks old) were divided into 2 equal groups (18 rats/group) as follows: normal and diarrheal rats. Normal rats were divided into 3 equal groups of 6 rats each: the control, shikimic acid, and desmopressin drug groups. Diarrheal rats were also divided into 3 equal groups of 6 rats each: diarrheal, diarrheal rats + shikimic acid, and diarrheal rats + desmopressin drug groups. Shikimic acid restored serum urea and creatinine, urinary volume, kidney weight, sodium, potassium, and chloride balance in serum and urine. The acid returned the antioxidant (superoxide dismutase, glutathione peroxidase, catalase, malondialdehyde, NADPH oxidase activity, conjugated dienes, and oxidative index) activity and the inflammatory markers (tumor necrosis factor-α, interleukin-1β, interleukin-6, and interleukin-10) to values approaching the control values. Shikimic acid also restored the sodium/potassium-ATPase activity, the apoptosis genes p53 and bcl-2, and the histology of kidney tissue in diarrheal rats to be near the control group.

CONCLUSIONS

Shikimic acid rescues diarrhea and its complications through restoring kidney function, serum and urinary electrolytes, antioxidant activity, inflammatory markers, sodium/potassium-ATPase activity, the apoptosis genes, and the histology of the kidney in diarrheal rats to approach the control one.

Shikimic acid (SA) inhibits neuro-inflammation and exerts neuroprotective effects in an LPS-induced in vitro and in vivo model

Numerous studies have shown that neuroinflammation is involved in the process of neuronal damage in neurodegenerative diseases such as Parkinson's disease (PD), for example, and that inhibiting neuroinflammation help improve PD. Shikimic acid (SA) has anti-inflammatory, analgesic and antioxidant activities in numerous diseases. However, its effect and mechanism in PD remain unclear. In this experiment, we found that SA inhibits production of pro-inflammatory mediators and ROS in LPS-induced BV2 cells. Mechanistic studies demonstrated that SA suppresses neuro-inflammation by activating the AKT/Nrf2 pathway and inhibiting the NF-κB pathway. Further in vivo study, we confirmed that SA ameliorated the neurological damage and behavioral deficits caused by LPS injection in mice. In summary, these study highlighted the beneficial role of SA as a novel therapy with potential PD drug by targeting neuro-inflammation.

Shikimic Acid Regulates the NF-κB/MAPK Signaling Pathway and Gut Microbiota to Ameliorate DSS-Induced Ulcerative Colitis

Shikimic acid (SA) is a compound extracted from the plant anise and has anti-inflammatory effects. However, any impact on intestinal inflammation or mechanisms involved has not been investigated. The present study used a dextran sulfate sodium (DSS)-induced mouse colitis model to investigate the effects of SA on intestinal inflammation. Intragastric administration of SA slowed DSS-induced weight loss, reduced disease activity index (DAI) score, enhanced the intestinal barrier, reduced the destruction of the colonic structure, inhibited the phosphorylation of key proteins in MAPK and NF-κB signaling pathways, inhibited the expression of inflammatory factors TNF-α, IL-1β, and MPO (P < 0.05), decreased IFN-γ expression (P < 0.05), and increased immunoglobulin IgG content (P < 0.05). After 50 mg/kg SA treatment, the content of Bacteroidetes increased and Proteobacteria decreased in the cecal feces of mice with colitis (P < 0.05) and the richness of gut species increased. In conclusion, SA could improve intestinal inflammation and enhance intestinal immunity, indicating its suitability as a therapeutic candidate.

Lansoprazole a Proton Pump Inhibitor Prevents IBD by Reduction of Oxidative Stress and NO Levels in the Rat

The inflammatory disease’s increased prevalence leads to a major concern around the world. Still, there is a lack of effective and successful therapy in the reversal of Inflammatory Bowel Disease (IBD) symptoms. Whereas, reactive oxygen species (ROS) production and muddled defense capacity of antioxidants in IBD subjects reported several times. Many proton pump inhibitors have been reported previously for their anti-inflammatory effect. The present study is aimed to assess the ameliorative effect of lansoprazole in experimentally induced IBD in rats. Thirty-six female Sprague Dawley rats were divided equally into six groups based on their body weight. Lansoprazole (1, 5, and 10 mg/kg, p.o.) and 5-aminosalicylate (5-ASA, 100 mg/kg, p.o.) served as standard control respectively, given for 18 days once a day. On the 11th day of the study, colitis was induced by intrarectal instillation of 2, 4-Dinitrobenzene sulfonic acid (DNBS), and treatment was continued for the next 7 days. Administration of lansoprazole (at 5 and 10 mg/kg) significantly reduced DAI (Disease Activation Index) and CMDI (Colon Macroscopic Damage Index); which further justifies a reduction in colon inflammation grades, as well as histopathological changes, and reflected by the stalling of body weight. The anti-inflammatory effects were indicated by lowered MPO (myeloperoxidase) and SOD (superoxide dismutase) in colon tissue as well as restores colonic NO (nitric oxide) level. The study shows lansoprazole improved DAI and CMDI scores, reduction of neutrophil infiltration, and an improved antioxidant status indicating an anti-ulcerative effect in DNBS-induced experimental colitis that is comparable with 5-ASA treatment.

Potential Mechanisms of 3, 4-Oxo-Isopropylidene-Shikimic Acid in Ameliorating 2, 4, 6-Trinitrobenzenesulfonic Acid-Induced Colitis in Rats

Previously, we reported that 3, 4-oxo-isopropylidene-shikimic acid (ISA) has therapeutic potential in experimental colitis in rats. This study aimed to elucidate the potential mechanisms of ISA on the inflammatory response in rats with 2, 4, 6-trinitrobenzenesulfonic acid-induced colitis. After the induction of colitis, rats were orally administered ISA for 12 days. Then, the expression levels of inflammatory cytokines, cell adhesion molecules, and matrix metalloproteinase (MMP) in the blood and colon tissues, and the protein level of nuclear factor kappa B (NF-κB) p65 in cytoplasm and nucleus of colon tissues were evaluated. As a result, an enhanced inflammatory response was observed in rats with experimental colitis. However, the treatment with ISA significantly ameliorated the inflammatory response, which was manifested as a significant decrease in the levels of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, interferon (IFN)-γ, IL-8, TNF-α mRNA, P-selectin, E-selectin, intercellular cell adhesion molecule-1, MMP9 and MMP9 mRNA in rat blood and colon tissues, respectively, and a significant decrease in the levels of IFN-γ/IL-4, and the NF-κBp65 activity coefficient. Therefore, the therapeutic effect of ISA on experimental colitis may be related to its inhibitory effect on the expression of cytokines, adhesion molecules, and MMP9, which may be involved in the inhibition of the activation and nuclear translocation of NF-κBp65.

Progress in active compounds effective on ulcerative colitis from Chinese medicines

Ulcerative colitis (UC), a chronic inflammatory disease affecting the colon, has a rising incidence worldwide. The known pathogenesis is multifactorial and involves genetic predisposition, epithelial barrier defects, dysregulated immune responses, and environmental factors. Nowadays, the drugs for UC include 5-aminosalicylic acid, steroids, and immunosuppressants. Long-term use of these drugs, however, may cause several side effects, such as hepatic and renal toxicity, drug resistance and allergic reactions. Moreover, the use of traditional Chinese medicine (TCM) in the treatment of UC shows significantly positive effects, low recurrence rate, few side effects and other obvious advantages. This paper summarizes several kinds of active compounds used in the experimental research of anti-UC effects extracted from TCM, mainly including flavonoids, acids, terpenoids, phenols, alkaloids, quinones, and bile acids from some animal medicines. It is found that the anti-UC activities are mainly focused on targeting inflammation or oxidative stress, which is associated with increasing the levels of anti-inflammatory cytokine (IL-4, IL-10, SOD), suppressing the levels of pro-inflammatory cytokines (TNF-α, IL-1β, IL-6, IL-8, IL-23, NF-κB, NO), reducing the activity of MPO, MDA, IFN-γ, and iNOS. This review may offer valuable reference for UC-related studies on the compounds from natural medicines.

Docosapentaenoic acid (DPA, 22:5n-3) ameliorates inflammation in an ulcerative colitis model

DPA showed an anti-inflammatory profile by competing with AA to decrease the synthesis of pro-inflammatory eicosanoids (LTB₄ and PGE₂).

Polysaccharides From Chrysanthemum morifolium Ramat Ameliorate Colitis Rats via Regulation of the Metabolic Profiling and NF-κ B/TLR4 and IL-6/JAK2/STAT3 Signaling Pathways

Studies have indicated that Chrysanthemum polysaccharides (CP) could prominently ameliorate colitis rats, but its possible mechanism remains unclear. In this study, the underlying mechanism of CP was explored by the metabolic profiling analysis and correlated signaling pathways. TNBS/ethanol induced colitis was used to investigate the intervention efficacy following oral administration of CP. The levels of cytokines such as TNF-α, IL-6, IFN-γ and IL-1β, and the activities of SOD, MPO, and MDA were determined. We also performed western-blot for p65, TLR4, p-JAK2, and STAT3 protein expression in the colon tissue to probe their mechanisms of correlated signaling pathways. What’s more, the metabolic changes in plasma and urine from colitis rats were investigated based on UPLC-Q-TOF/MS combined with Metabolynx^TM software. The potential biomarkers and metabolic pathways were also tentatively confirmed. The metabolic profiles of plasma and urine were clearly improved in model rats after oral administration of CP. Thirty-two (17 in serum and 15 in urine) potential biomarkers were identified. The endogenous metabolites were mainly involved in linoleic acid, retinol, arachidonic acid, glycerophospholipid and primary bile acid metabolism in plasma, and nicotinate and nicotinamide, ascorbate and aldarate, histidine and β-alanine metabolism in urine. After polysaccharides intervention, these markers turned back to normal level at some extent. Meanwhile, the elevated expression levels of pp65, TLR4, p-STAT3, and p-JAK2 were significantly decreased after treatment. Results suggested that CP would be a potential prebiotics for alleviation of TNBS-induced colitis. The study paved the way for the further exploration of the pathogenesis, early diagnosis and curative drug development of the colitis.

The protective effects of magnolol on acute trinitrobenzene sulfonic acid‑induced colitis in rats

The present study aimed to investigate the protective effects of magnolol on acute 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colitis, and its underlying mechanisms. Experimental colitis was induced by intracolonic administration of TNBS/ethanol into rats. The model rats were randomly assigned into groups: TNBS, magnolol (high, medium and low doses), and salazosulfapyridine (positive control). All intervention regimens were administered by oral gavage, once a day for 7 consecutive days, 24 h after colitis induction. Histological and biochemical changes in colonic inflammation were evaluated by hematoxylin and eosin and immunohistochemistry, respectively. Rats treated with all doses of magnolol exhibited decreased colonic myeloperoxidase activity (P<0.05 vs. TNBS), reduced serum levels of proinflammatory cytokines [including interleukin (IL)-6 and IL-17], and downregulated Toll-like receptor-4 (TLR-4) mRNA expression. Histological analysis revealed that medium and high doses of magnolol conferred an anti-inflammatory effect, which was indicated by a decrease in disease activity index, an increase in thymus index, and downregulation of nuclear factor (NF)-κB p65 mRNA and TLR-4 protein expression. However, only high-dose magnolol significantly ameliorated the elevated colon weight/length ratio. The results of the present study indicate that magnolol exerts protective effects against acute TNBS-induced colitis in rats, and the TLR-4/NF-κB signaling pathway-mediated inhibitory effect on inflammatory cascades may contribute to the protective activity of magnolol.

Shikimic acid inhibits LPS-induced cellular pro-inflammatory cytokines and attenuates mechanical hyperalgesia in mice

BACKGROUND AND AIMS

Shikimic acid (SA) is present in a wide variety of plants and microorganisms used in traditional and folk medicine and also is an essential starting material for the synthesis of the antiviral drug Oseltamivir (Tamiflu®). Some pharmacological actions observed in SA-enriched products include antioxidant and anti-inflammatory activities. Here, we investigated the anti-inflammatory and antinociceptive actions of isolated SA.

METHODS

RAW 264.7 macrophage cells were treated with bacterial LPS (1μg/mL) and the effect of SA on the modulation of cell viability, nitric oxide (NO) production, TNF-α, and IL-1β content and MAPK (ERK1/2 and p38) activation was evaluated. Besides, the anti-hyperalgesic actions of SA on in vivo model of mechanical hyperalgesia induced by carrageenan (CG), dopamine (DA), TNF-α and prostaglandin (PGE2) were assessed.

RESULTS

In RAW 264.7 cells, SA suppressed LPS-induced decrease in cell viability and nitrite accumulation to control values and inhibited up-regulation of TNF-α (65%) and IL-1β (39%). These effects may be mediated at least in part by inhibition of LPS-induced ERK 1/2 (22%) and p38 (17%) phosphorylation. In mice, SA at 50, 100, and 200mg/kg decreased formalin-induced nociceptive behavior (around 50%) and inhibited the inflammatory nociception induced by TNF-α and PGE2 (50 to 75% each). Moreover, SA (100 and 200mg/kg) significantly attenuated the mechanical hyperalgesia induced by CG and DA (25 to 40% each).

CONCLUSIONS

These results indicate that SA presents anti-inflammatory actions with potential for development of drugs to treat pro-inflammatory and painful conditions.

Antioxidant therapy for treatment of inflammatory bowel disease: Does it work?

Oxidative stress (OS) is considered as one of the etiologic factors involved in several signals and symptoms of inflammatory bowel diseases (IBD) that include diarrhea, toxic megacolon and abdominal pain. This systematic review discusses approaches, challenges and perspectives into the use of nontraditional antioxidant therapy on IBD, including natural and synthetic compounds in both human and animal models. One hundred and thirty four papers were identified, of which only four were evaluated in humans. Some of the challenges identified in this review can shed light on this fact: lack of standardization of OS biomarkers, absence of safety data and clinical trials for the chemicals and biological molecules, as well as the fact that most of the compounds were not repeatedly tested in several situations, including acute and chronic colitis. This review hopes to stimulate researchers to become more involved in this fruitful area, to warrant investigation of novel, alternative and efficacious antioxidant-based therapies.

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Major biomarkers used for evaluation of antioxidant therapy were MPO, TBARS/MDA and glutathione levels.

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Challenges were identified for the yet poor use of antioxidant therapy in IBD.

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This review stimulates the investigation of alternative and efficacious antioxidant therapies.

Anti-inflammatory effects of Huangqin tang extract in mice on ulcerative colitis

ETHNOPHARMACOLOGICAL RELEVANCE

HuangqinTang (HQT) is a traditional Chinese formula which is composed of Scutellaria baicalensis Georgi, Paeonia lactiflora Pall, Glycyrrhiza uralensis Fisch, and Ziziphus jujube Mill. HQT has been used in China for a wide range of disorders, especially in gastrointestinal inflammation with symptoms of nausea, vomiting, diarrhea, abdominal cramps and so on.

AIM OF THE STUDY

To investigate the protective effects of HQT extract on 2, 4, 6-trinitrobenzenesulfonic acid (TNBS) induced colitis in mice.

MATERIALS AND METHODS

Different doses of HQT extract (1, 2 and 4 g/kg/day) and salicylazosulfapyridine (SASP, 500 mg/kg/day) were administered by gavage for 7 days after the induction of colitis with TNBS. The effects were studied by macroscopic score, histological analysis, immunohistochemical study of Cyclo-oxygenase-2 protein expression, as well as by determination of inflammation markers such as myeloperoxidase (MPO) and mRNA expression levels of pro-inflammatory cytokines, including TNF-α, IL-1β and IL-6.

RESULTS

In TNBS induced group, mice body weight decreased gradually and did not recover at the end of the experiment, as compared with that of control group (p<0.01). Edema and redness were also discovered in the colons profoundly and scores representing inflammation were all high in this group (p<0.01). The level of colonic MPO activity and the tissue levels of TNF-α, IL-1β and IL-6 were markedly increased (p<0.01). The mice treated with HQT extract and SASP recovered significantly compared with the TNBS group (p<0.01).

CONCLUSION

Our results suggested that the efficacy of HQT extract, especially at the higher dose, was analogous to that of SASP, which implicated its potential application as a natural alternative medicine in colitis treatment.

Extraction and Chromatographic Determination of Shikimic Acid in Chinese Conifer Needles with 1-Benzyl-3-methylimidazolium Bromide Ionic Liquid Aqueous Solutions

An ionic liquids-based ultrasound-assisted extraction (ILUAE) method was successfully developed for extracting shikimic acid from conifer needles. Eleven 1-alkyl-3-methylimidazolium ionic liquids with different cations and anions were investigated and 1-benzyl-3-methylimidazolium bromide solution was selected as the solvent. The conditions for ILUAE, including the ionic liquid concentration, ultrasound power, ultrasound time, and liquid-solid ratio, were optimized. The proposed method had good recovery (99.37%-100.11%) and reproducibility (RSD, n = 6; 3.6%). ILUAE was an efficient, rapid, and simple sample preparation technique that showed high reproducibility. Based on the results, a number of plant species, namely, Picea koraiensis, Picea meyeri, Pinus elliottii, and Pinus banksiana, were identified as among the best resources of shikimic acid.

Protective and worsening peripheral nociceptin/orphanin FQ receptor-mediated effect in a rat model of experimental colitis

Nociceptin/orphanin FQ (N/OFQ) and nociceptin orphanin peptide (NOP) receptors represent an endogenous system modulating gastrointestinal functions and inflammation. We investigated the peripheral effect of N/OFQ and of UFP-101, the NOP antagonist, in a model of colitis induced by TNBS (2,4,6 trinitrobenzenesulphonic acid; 60mg/kg). Male rats received two intraperitoneal injections per day of N/OFQ, UFP-101 or saline for 3 days after colitis induction. Four days after TNBS, animals were sacrificed and colonic histological damage, myeloperoxidase (MPO) activity and cytokine (IL-1β and IL-10) levels were evaluated. N/OFQ plasmatic levels were assessed by radioimmunoassay. TNBS increased all the inflammatory variables considered. In colitic rats, N/OFQ (0.02 and 0.2nmol/kg) improved microscopic damage, MPO activity and decreased IL-1β levels in comparison with TNBS group, whereas at the highest dose (20nmol/kg) the peptide worsened colitis. UFP-101 at the dose of 1nmol/kg, without pharmacological activity, antagonised the protective effect of N/OFQ (0.2nmol/kg) on colitis, but at a dose level of 3 and 10nmol/kg worsened inflammation, revealing the endogenous N/OFQergic system protective role. N/OFQ plasmatic levels were not modified in TNBS-treated rats compared with controls, whereas they were reduced in rats treated with the doses of UFP-101 aggravating colitis. In conclusion, peripheral low doses of N/OFQ have a beneficial effect on colonic inflammation in rats. In contrast, N/OFQ at a dose 100-1000-fold higher than those that protect worsens colitis, probably through different mechanisms. The peripheral N/OFQergic system can represent a new field of investigation in some intestinal inflammatory conditions.

Ameliorative effects of 3,4-oxo-isopropylidene-shikimic acid on experimental colitis and their mechanisms in rats

The aim of the present study was to investigate the therapeutic effect and mechanism of 3,4-oxo-isopropylidene-shikimic acid (ISA) on 2,4,6-trinitrobenzenesulfonic acid (TNBS)-induced colitis in rats. (50, 100, 200 mg/kg) was administered for 14 days, 1 day after the induction of colitis by TNBS. The colonic injury and inflammation were assessed by macroscopic damage scores and myeloperoxidase (MPO) activity. Malondialdehyde (MDA) and nitric oxide (NO) levels, and superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities in plasma were measured with biochemical methods. Prostaglandin E2 (PGE2) level in colon was determined by radioimmunoassay. Expressions of inducible nitric oxide synthase (iNOS), cyclo-oxygenase-2 (COX-2), inhibitor kappa B-alpha (IκBα) and nuclear factor kappa B (NF-κB) p65 proteins in the colonic tissue were detected with immunohistochemistry. Enhanced colonic mucosal injury, inflammatory response and oxidative stress were observed in the animals clystered with TNBS, which was manifested as the significant increase in colon mucosal damage index, MPO activity, levels of MDA, NO and PGE2, as well as the expressions of iNOS, COX-2 and NF-κB p65 proteins in the colonic mucosa, and the significant decrease in expressions of IκBα proteins in the colonic mucosa. However, these parameters were found to be significantly ameliorated in rats treated with ISA at given doses, especially at 100 mg/kg and 200 mg/kg. Administration of ISA may have significant therapeutic effects on experimental colitis in rats, probably due to its mechanism of antioxidation, its inhibition of arachidonic acid metabolism and its modulation of the IκBα/NF-κB p65 expression.