Curcumin Inhibits STAT3 Signaling in the Colon of Dextran Sulfate Sodium-treated Mice

A strategic review of STAT3 signaling inhibition by phytochemicals for cancer prevention and treatment: Advances and insights

Cancer remains a significant global health concern. The dysregulation of signaling networks in tumor cells greatly affects their functions. This review intends to explore phytochemicals possessing potent anticancer properties that specifically target the STAT3 signaling pathway, elucidating strategies and emphasizing their potential as promising candidates for cancer therapy. The review comprehensively examines various STAT3 inhibitors designed to disrupt the signaling cascade, including those targeting upstream activation, SH2 domain phosphorylation, DNA binding domain (DBD), N-terminal domain (NTD), nuclear translocation, and enhancing endogenous STAT3 negative regulators. A literature review was conducted to identify phytochemicals with anticancer activity targeting the STAT3 signaling pathway. Popular research databases such as Google Scholar, PubMed, Science Direct, Scopus, Web of Science, and ResearchGate were searched from the years 1989 - 2023 based on the keywords "Cancer", "STAT3", "Phytochemicals", "Phytochemicals targeting STAT3 signaling", "upstream activation of STAT3", "SH2 domain of STAT3", "DBD of STAT3", "NTD of STAT3, "endogenous negative regulators of STAT3", or "nuclear translocation of STAT3", and their combinations. A total of 264 relevant studies were selected and analyzed based on the mechanisms of action and the efficacy of the phytocompounds. The majority of the discussed phytochemicals primarily focus on inhibiting upstream activation of STAT3. Additionally, flavonoid and terpenoid compounds exhibit multifaceted effects by targeting one or more checkpoints within the STAT3 pathway. Analysis reveals that phytochemicals targeting upstream activation predominantly belong to the classes of flavonoids and terpenoids, which hold significant promise as effective anticancer therapeutics. Future research in this field can be directed towards exploring and developing these scrutinized classes of phytochemicals to achieve desired therapeutic outcomes in cancer treatment.

Drosophila: An Important Model for Exploring the Pathways of Inflammatory Bowel Disease (IBD) in the Intestinal Tract

Inflammatory bowel disease (IBD) is a chronic and recurring lifelong condition, the exact etiology of which remains obscure. However, an increasing corpus of research underscores the pivotal role of cellular signaling pathways in both the instigation and management of intestinal inflammation. Drosophila, owing to its prodigious offspring, abbreviated life cycle, and the conservation of signaling pathways with mammals, among other advantages, has become a model organism for IBD research. This review will expound on the feasibility of utilizing Drosophila as an IBD model, comparing its intestinal architecture with that of mammals, its inflammatory responses, and signaling pathways. Furthermore, it will deliberate on the role of natural products across various biological models of IBD pathways, elucidating the viability of fruit flies as IBD models and the modus operandi of cellular signaling pathways in the context of IBD.

Chromatographic analysis of the chemical composition and anticancer activities of Curcuma longa extract cultivated in Palestine

Curcuma longa (turmeric) is a plant that has been extensively utilized in traditional medicine for centuries. Turmeric has a long history of use in both food and traditional medicine for the treatment of ailments such as diarrhea, cancer, flatulence, and dyspepsia. In Palestine, this plant was cultivated for the first time. The objective of this study was to characterize the extract of C. longa and assess its antimutagenic activity against a variety of cancer cells. Gas chromatography-mass spectrometry (GC-MS) and high-performance liquid chromatography (HPLC) methods were employed to identify the constituents of turmeric. The cytotoxic effects of C. longa were evaluated on cancer and normal cell lines using the 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium assay. The results revealed the presence of 10 components in turmeric extract as identified by GC-MS. The major constituents comprising 78% of the total constituents were α-zingiberene (27.51%), tumeron (19.44%), β-sesquiphellandrene (19.40%), and aromatic-tumeron (11.63%). HPLC analysis successfully separated the main constituent, curcumin (1.78%), along with two other curcumin derivatives. The cytotoxicity results demonstrated potent anticancer activity of the C. longa extract against HeLa and LX2 cell lines, with IC50 values of 46.84 ± 2.12 and 29.77 ± 1 µg/mL, respectively. Furthermore, the plant extract at a concentration of 250 µg/mL exhibited over 95% inhibition against all tested cancer cell lines. These findings highlight the promising potential of turmeric as a natural source with powerful anticancer activities. Moreover, the extract may possess other biological activities such as antioxidant and antimicrobial properties, which could be explored in future studies.

A review on curcumin colon-targeted oral drug delivery systems for the treatment of inflammatory bowel disease

Synthetic drugs and monoclonal antibodies are the typical treatments to combat inflammatory bowel disease (IBD). However, side effects are present when these treatments are used, and their continued application could be restricted by the high relapse rate of the disease. One potential alternative to these treatments is the use of plant-derived products. The use curcumin is one such treatment option that has seen an increase in usage in treating IBD. Curcumin is derived from a rhizome of turmeric (Curcuma longa), and the results of studies on the use of curcumin to treat IBD are promising. These studies suggest that curcumin interacts with cellular targets such as NF-κB, JAKs/STATs, MAPKs, TNF-α, IL-6, PPAR, and TRPV1 and may reduce the progression of IBD. Potentially, curcumin can be used as a therapeutic agent for patients with IBD when it reduces the incidence of clinical relapse. This review discusses the strategies utilized in designing and developing an oral colonic delivery dosage form of curcumin.

Using Drosophila melanogaster as a suitable platform for drug discovery from natural products in inflammatory bowel disease

Inflammatory bowel disease (IBD) is a chronic and life-treating inflammatory disease that can occur in multiple parts of the human intestine and has become a worldwide problem with a continually increasing incidence. Because of its mild early symptoms, most of them will not attract people's attention and may cause more serious consequences. There is an urgent need for new therapeutics to prevent disease progression. Natural products have a variety of active ingredients, diverse biological activities, and low toxicity or side effects, which are the new options for preventing and treating the intestinal inflammatory diseases. Because of multiple genetic models, less ethical concerns, conserved signaling pathways with mammals, and low maintenance costs, the fruit fly Drosophila melanogaster has become a suitable model for studying mechanism and treatment strategy of IBD. Here, we review the advantages of fly model as screening platform in drug discovery, describe the conserved molecular pathways as therapetic targets for IBD between mammals and flies, dissect the feasibility of Drosophila model in IBD research, and summarize the natural products for IBD treatment using flies. This review comprehensively elaborates that the benefit of flies as a perfact model to evaluate the therapeutic potential of phytochemicals against IBD.

Therapeutic Potential of Curcumin in a Rat Model of Dextran Sulfate Sodium-Induced Ulcerative Colitis by Regulating the Balance of Treg/Th17 Cells

The pathogenesis of ulcerative colitis (UC) remains unclear, and it is believed that an imbalance of regulatory T (Treg) cells and T helper 17 (Th17) cells is related to the occurrence of UC. Curcumin has been confirmed to exert anti-inflammatory effects in bronchial asthma and osteoarthritis by regulating the balance of Treg/Th17 cells. This study aimed to explore the therapeutic potential of curcumin in dextran sulfate sodium (DSS)-induced UC rats by regulating the balance of Treg/Th17 cells. Disease activity index (DAI) scores were calculated. Changes in colon inflammation were observed using hematoxylin and eosin staining. Treg and Th17 cells in the spleen were detected by flow cytometry, and the levels of interleukin (IL)-10 and IL-17A were determined using enzyme-linked immunosorbent assay. In DSS-induced colitis, curcumin significantly ameliorated colitis symptoms by reducing the DAI and increasing colon length. Additionally, curcumin significantly increased the expression of Treg cells and decreased the expression of Th17 cells and the extent of histopathological damage. Furthermore, curcumin increased the expression of IL-10 and decreased the expression of IL-17A. Curcumin attenuates DSS-induced UC injury by regulating Treg/Th17 balance and related cytokine secretion. Thus, curcumin may be a promising therapeutic drug for treating UC.

Curcumin and Curcuma longa Extract in the Treatment of 10 Types of Autoimmune Diseases: A Systematic Review and Meta-Analysis of 31 Randomized Controlled Trials

Objective

To evaluate the randomized controlled trials (RCTs) of Curcumin and Curcuma longa Extract in the treatment of autoimmune diseases.

Methods

Databases such as Embase, Web of Science, PubMed and The Cochrane Library were searched from the database establishment to February 2022 to collect RCTs of Curcumin and Curcuma longa Extract in the treatment of autoimmune diseases. Then the literature was screened and the data were extracted. Meta-analysis was performed using RevMan 5.3 software.

Results

A total of 34 records were included, involving 31 RCTs and 10 types of autoimmune disease. Among them, ankylosing spondylitis (AS) involves one RCT, Behcet ‘s disease (BD) involves one RCT, Crohn ‘s disease involves two RCTs, multiple sclerosis (MS) involves two RCTs, oral lichen planus involves six RCTs, psoriasis involves two RCTs, rheumatoid arthritis (RA) involves five RCTs, systemic lupus erythematosus (SLE) involves two RCTs, arteritis involves one RCT, ulcerative colitis (UC) involves nine RCTs. Among them, most of the RCTs of ulcerative colitis (UC), oral lichen planus, RA showed that curcumin and curcumin extracts improved clinical or laboratory results. Crohn ‘ s disease, MS, SLE, psoriasis included two RCTs; they all showed improvements (at least one RCT reported improvements in clinical outcomes). AS, BD and arteritis included only one RCT, and the clinical results showed improvement. However, due to the small number of RCTs and the small number of patients involved in each disease, there is still a need for more high-quality RCTs.

Conclusion

Curcumin and Curcuma longa Extract had good clinical efficacy in the treatment of Psoriasis, UC and RA, so Curcumin and Curcuma longa Extract could be used in the treatment of the above diseases in the future. The results of Meta-analysis showed that Curcumin and Curcuma longa Extract did not show efficacy in the treatment of oral lichen planus, while Takayasu arteritis, SLE, MS, AS, BD and CD did not report sufficient clinical data for meta-analysis. Therefore, large-sample, multi-center clinical trials are still needed for revision or validation.

Review of the Effects and Mechanism of Curcumin in the Treatment of Inflammatory Bowel Disease

Curcumin is extracted from the rhizomes of Curcuma longa L. It is now widely used in food processing, cosmetics, dyes, etc. Current researching indicates that curcumin has high medical value, including anti-inflammatory, antioxidant, anti-tumor, anti-apoptotic, anti-fibrosis, immune regulation and other effects, and can be used to treat a variety of diseases. Inflammatory bowel disease (IBD) is a nonspecific inflammatory disease of the intestine including Crohn’s disease (CD) and ulcerative colitis (UC). The drug treatment effect is often limited and accompanied by side effects. A large number of basic and clinical studies have shown that curcumin has the effect of treating IBD and also can maintain the remission of IBD. In this review, the research of curcumin on IBD in recent years is summarized in order to provide reference for further research and application of curcumin.

Phytochemicals Targeting JAK-STAT Pathways in Inflammatory Bowel Disease: Insights from Animal Models

Inflammatory bowel disease (IBD) is a chronic inflammatory disorder of the gastrointestinal tract that consists of Crohn’s disease (CD) and ulcerative colitis (UC). Cytokines are thought to be key mediators of inflammation-mediated pathological processes of IBD. These cytokines play a crucial role through the Janus kinase (JAK) and signal transducer and activator of transcription (STAT) signaling pathways. Several small molecules inhibiting JAK have been used in clinical trials, and one of them has been approved for IBD treatment. Many anti-inflammatory phytochemicals have been shown to have potential as new drugs for IBD treatment. This review describes the significance of the JAK–STAT pathway as a current therapeutic target for IBD and discusses the recent findings that phytochemicals can ameliorate disease symptoms by affecting the JAK–STAT pathway in vivo in IBD disease models. Thus, we suggest that phytochemicals modulating JAK–STAT pathways are potential candidates for developing new therapeutic drugs, alternative medicines, and nutraceutical agents for the treatment of IBD.

Role of Photoactive Phytocompounds in Photodynamic Therapy of Cancer

Cancer is one of the greatest life-threatening diseases conventionally treated using chemo- and radio-therapy. Photodynamic therapy (PDT) is a promising approach to eradicate different types of cancers. PDT requires the administration of photosensitisers (PSs) and photoactivation using a specific wavelength of light in the presence of molecular oxygen. This photoactivation exerts an anticancer effect via apoptosis, necrosis, and autophagy of cancer cells. Recently, various natural compounds that exhibit photosensitising potentials have been identified. Photoactive substances derived from medicinal plants have been found to be safe in comparison with synthetic compounds. Many articles have focused on PDT mechanisms and types of PSs, but limited attention has been paid to the phototoxic activities of phytocompounds. The reduced toxicity and side effects of natural compounds inspire the researchers to identify and use plant extracts or phytocompounds as a potent natural PS candidate for PDT. This review focusses on the importance of common photoactive groups (furanocoumarins, polyacetylenes, thiophenes, curcumins, alkaloids, and anthraquinones), their phototoxic effects, anticancer activity and use as a potent PS for an effective PDT outcome in the treatment of various cancers.

Hot-water extract of ripened Pu-erh tea attenuates DSS-induced colitis through modulation of the NF-κB and HIF-1α signaling pathways in mice

Tea consumption has been found to be associated with low incidence of inflammatory bowel disease in Asian countries. However, there is very limited knowledge of such potential protection and its underlying mechanism. Ripened Pu-erh tea (RPT) belongs to the variety of microbial fermented tea, but its function regarding anti-inflammation remains unclear. In the present study, we investigated the effects of RPT on dextran sulfate sodium (DSS)-induced colitis in mice. The results demonstrated that RPT significantly relieved the loss of body weight, disease severity and shortening of colon length, and remarkably inhibited the secretion of pro-inflammatory cytokines by lessening the infiltration of inflammatory cells. Furthermore, we found that RPT suppressed the activation of the NF-κB pathway and down-regulated the expression of HIF-1α. Thus, it was concluded that RPT attenuated the progress of colitis via suppressing the HIF-1α/NF-κB signaling pathways thus reducing inflammation. This suggests that RPT may be a potential anti-inflammatory nutraceutical for the prevention and treatment of colonic colitis.

Phytochemical drug candidates for the modulation of peroxisome proliferator-activated receptor γ in inflammatory bowel diseases

Plant-based compounds or phytochemicals such as alkaloids, glycosides, flavonoids, volatile oils, tannins, resins, and polyphenols have been used extensively in traditional medicine for centuries and more recently in Western alternative medicine. Extensive evidence suggests that consumption of dietary polyphenolic compounds lowers the risk of inflammatory diseases. The anti-inflammatory properties of several phytochemicals are mediated through ligand-inducible peroxisome proliferator-activated receptors (PPARs), particularly the PPARγ transcription factor. Inflammatory bowel disease (IBD) is represented by ulcerative colitis, which occurs in the mucosa of the colon and rectum, and Crohn's disease (CD) that can involve any segment of gastrointestinal tract. Because of the lack of cost-effective pharmaceutical treatment options, many IBD patients seek and use alternative and unconventional therapies to alleviate their symptoms. PPARγ plays a role in the inhibition of inflammatory cytokine expression and activation of anti-inflammatory immune cells. The phytochemicals reported here are ligands that activate PPARγ, which in turn modulates inflammatory responses. PPARγ is highly expressed in the gut making it a potential therapeutic target for IBDs. This review summarizes the effects of the currently published phytochemicals that modulate the PPARγ pathway and reduce or eliminate colonic inflammation.

Curcumin - A Novel Therapeutic Agent in the Prevention of Colorectal Cancer

Background:

Colorectal cancer is the third important cause of cancer-associated deaths across the world. Hence, there is an urgent need for understanding the complete mechanism associated with colorectal cancer, which in turn can be utilized toward early detection as well as the treatment of colorectal cancer in humans. Though colorectal cancer is a complex process and chemotherapy is the first step toward the treatment of colorectal cancer, recently several studies suggested that dietary phytochemicals may also aid significantly in reducing colorectal cancer risk in human. However, only few phytochemicals, specifically curcumin derived from the rhizomes of Curcuma longa, have better chemotherapeutic property, which might be because of its ability to regulate the activity of key factors associated with the initiation, promotion, as well as progression of tumors.

Objectives:

In the present review, the authors made an attempt to summarize the physiochemical properties of curcumin, which in turn prevent colorectal cancer via regulating numerous cell signaling as well as genetic pathways.

Conclusions:

Accumulated evidence suggested that curcumin suppresses tumour/colon cancer in various ways, (a) restricting cell cycle progression, or stimulating apoptosis, (b) restricting angiogenesis, anti-apoptotic proteins expression, cell survival signaling pathways & their cross-communication and (c) regulating immune responses. The information discussed in the present review will be useful in the drug discovery process as well as the treatment and prevention of colorectal cancer in humans.

Application of Herbaceous Medications for Inflammatory Bowel Disease as a Complementary and Alternative Therapy

BACKGROUND

Conventional medicine for the treatment of IBD is prevailingly composed of sulfadiazine, 5-aminosalicylic acid, glucocorticoid, and immunosuppressants, which have the merits of alleviating intestine inflammation, but long-term use of these drugs may cause toxic side effects; additionally, these drugs may be expensive. In the pursuit of novel and more economic therapies, patients may increasingly look at complementary and alternative medicine (CAM). Recently, CAM is increasingly favored by the general public on account of its safety, low toxicity, and effectiveness. As a branch of CAM, herbal plants and their extracts have a significant effect on the treatment of IBD. Treatment of IBD with herbaceous plants has been reported, but specific mechanisms and effects have not yet been elaborated.

METHODS

English abstracts were identified in PubMed and Science Direct by multiple search terms, such as "herbal," "CAM," "IBD," "ulcerative colitis," "abdominal pain," and so on. Full-length articles were selected for review.

RESULTS

Herbaceous plants and their extracts have been shown to be effective against IBD in many studies, and herbaceous plants may be effective in treating symptoms such as abdominal pain, diarrhea, mucus, and bloody stools.

CONCLUSIONS

Herbal medications could be used as a complementary and alternative treatment for IBD, but they require more rigorous scientific testing.

Molecular mechanisms of curcumin and its analogs in colon cancer prevention and treatment

Colorectal cancer remains to be the most prevalent malignancy in humans and 1.5 million men and women living in the United States are diagnosed with colorectal cancer, with a predicted 145,600 new cases to be diagnosed in 2019. Curcuminoids and its synthetic analogs are now of interest due to their bioactive attributes, especially their action as anticancer activity in various cancer cell line models. Several in vivo and in vitro studies have substantially proved their anticancer activities against colon cancer cell lines. Curcumin analogues like IND-4, FLLL, GO-Y030 and C086 have demonstrated to produce greater cytotoxicity when experimentally studied and study results from many have been suggested to be the same. Combination of curcumin with therapeutic cancer agents like tolfenamic acid, 5-fluorouracil, resveratrol and dasatinib showed improved cytotoxicity and chemotherapeutic effect. The results propose that employment of curcumin with novel drug delivery systems like liposome, micelles and nanoparticle have been performed which could improve the therapeutic efficacy against colon cancer. The present review highlights the mechanism of action, synergistic effect and novel delivery methods to improve the therapeutic potential of curcumin.

Baicalein Inhibits Dextran Sulfate Sodium-induced Mouse Colitis

Background

Baicalein is a bioactive flavone that is originally extracted from the root of Scutellaria baicalensis Georgi. This plant has long served as Chinese herbal medicine in the management of multiple diseases including inflammatory bowel diseases. Although it has been revealed that baicalein inhibits experimental colitis in mice, the molecular mechanisms still remain largely unrecognized.

Methods

The experimental colitis was induced in mice by 3% dextran sulfate sodium (DSS) in drinking water. The mice were given baicalein (10 or 25 mg/kg) by gavage for 7 days before and after DSS administration. Expression of COX-2 and inducible nitric oxide synthase (iNOS) and molecules involved in NF-κB signaling, such as inhibitor of κBα (IκBα), pIκBα, p65, and phospho-p65 was examined by Western blot analysis in the tissue of the mouse colon. Activity of IκB kinase β (IKKβ) was assessed by measuring the relative amount of radioactive γ-phosphate of ATP transferred to the IκBα substrate protein. The expression and phosphorylation of STAT3 and its target gene cyclin D1 were also measured.

Results

Baicalein prominently mitigated the severity of DSS-induced colitis in mice. It inhibited the expression of COX-2 and iNOS. Moreover, baicalein attenuated activity and phosphorylation of IKKβ and subsequent degradation of IκBα. Baicalein suppressed the phosphorylation and nuclear translocation of p65, resulting in a reduced DNA binding activity of NF-κB. Baicalein also suppressed the phosphorylation of STAT3 and expression of cyclin D1. Baicalein exhibited the synergistic effect on inhibition of COX-2 induced by DSS with curcumin, an ingredient of turmeric.

Conclusions

Protective effects of baicalein on DSS-induced colitis are associated with suppression of NF-κB and STAT3 signaling pathways, which may contribute to its cancer preventive effects on colon carcinogenesis.

Phytochemicals and inflammatory bowel disease: a review

Gastrointestinal tract is the second largest organ in the body that mainly functions in nutrients and minerals intake through the intestinal barrier. Intestinal permeability maintains the circulation of minerals and nutrients from digested foods. Life and all the metabolic processes depend either directly or indirectly on proper functioning of GI tract. Compromised intestinal permeability and related disorders are common among all the patients with inflammatory bowel disease (IBD), which is a collective term of inflammatory diseases including Crohn's disease and ulcerative colitis. Many synthetic drugs are currently in use to treat IBD such as 5-aminosalicylic acid corticosteroids. However, they all have some drawbacks as long-term use result in many complications. These problems encourage us to look out for alternative medicine. Numerous in vitro and in vivo experiments showed that the plant-derived secondary metabolites including phenolic compounds, glucosinolates, alkaloids, terpenoids, oligosaccharides, and quinones could reduce permeability, ameliorate-related dysfunctions with promising results. In addition, many of them could modulate enzymatic activity, suppress the inflammatory transcriptional factors, ease oxidative stress, and reduce pro-inflammatory cytokines secretion. In this review, we summarized the phytochemicals, which were proven potent in treating increased intestinal permeability and related complication along with their mechanism of action.

Dietary phytochemicals in colorectal cancer prevention and treatment: A focus on the molecular mechanisms involved

Worldwide, colorectal cancer (CRC) remains a major cancer type and leading cause of death. Unfortunately, current medical treatments are not sufficient due to lack of effective therapy, adverse side effects, chemoresistance and disease recurrence. In recent decades, epidemiologic observations have highlighted the association between the ingestion of several phytochemical-enriched foods and nutrients and the lower risk of CRC. According to preclinical studies, dietary phytochemicals exert chemopreventive effects on CRC by regulating different markers and signaling pathways; additionally, the gut microbiota plays a role as vital effector in CRC onset and progression, therefore, any dietary alterations in it may affect CRC occurrence. A high number of studies have displayed a key role of growth factors and their signaling pathways in the pathogenesis of CRC. Indeed, the efficiency of dietary phytochemicals to modulate carcinogenic processes through the alteration of different molecular targets, such as Wnt/β-catenin, PI3K/Akt/mTOR, MAPK (p38, JNK and Erk1/2), EGFR/Kras/Braf, TGF-β/Smad2/3, STAT1-STAT3, NF-кB, Nrf2 and cyclin-CDK complexes, has been proven, whereby many of these targets also represent the backbone of modern drug discovery programs. Furthermore, epigenetic analysis showed modified or reversed aberrant epigenetic changes exerted by dietary phytochemicals that led to possible CRC prevention or treatment. Therefore, our aim is to discuss the effects of some common dietary phytochemicals that might be useful in CRC as preventive or therapeutic agents. This review will provide new guidance for research, in order to identify the most studied phytochemicals, their occurrence in foods and to evaluate the therapeutic potential of dietary phytochemicals for the prevention or treatment of CRC by targeting several genes and signaling pathways, as well as epigenetic modifications. In addition, the results obtained by recent investigations aimed at improving the production of these phytochemicals in genetically modified plants have been reported. Overall, clinical data on phytochemicals against CRC are still not sufficient and therefore the preventive impacts of dietary phytochemicals on CRC development deserve further research so as to provide additional insights for human prospective studies.

Dietary polysaccharide-rich extract from Eucheuma cottonii modulates the inflammatory response and suppresses colonic injury on dextran sulfate sodium-induced colitis in mice

Inflammatory bowel disease (IBD) is a known medical burden in most developed countries and a significant cause of morbidity. The IBD label includes Crohn's disease (CD) and ulcerative colitis (UC). Pharmacological and surgical intervention are the two main management approaches for IBD. Some drugs have been developed for IBD therapy, but accessibility is limited due to high costs. Furthermore, these agents have demonstrated inactivity over long-term treatment courses. Therefore, an urgent need is present for new treatment options that are safe, able to sustain clinical remission, and improve mucosal gut healing. Seaweed has received much attention in the pharmacological field owing to its various biomedical properties, including the prolongation of blood clotting time, as well as antitumor, anti-inflammation, and antioxidant effects. This study therefore aimed to examine the effects of a dietary polysaccharide-rich extract obtained from Eucheuma cottonii (EC) on a model of colitis. Colitis was induced in male BALB/c mice by the administration of 2.5% (w/v) dextran sulfate sodium (DSS) for 7 days. DSS-induced mice were treated with either one of three different doses of EC extracts (0.35, 0.70, and 1.75 g/kg body weight) or curcumin as a positive control (0.10 g/kg). Mice were sacrificed post-treatment and blood samples were collected. The disease activity index (DAI) and inflammatory cytokine levels (tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, IL-10) were measured. After treatment for 7 days, EC extract administration protected against weight loss and decreased the colon weight per length ratio. EC extract administration also decreased pro-inflammatory cytokine expression, increased IL-10 levels, and reduced colonic damage. Therefore, a dietary polysaccharide-rich extract from E. cottonii reduced DSS-induced bowel inflammation, thereby becoming a promising candidate for the treatment of colitis.

The versatile role of curcumin in cancer prevention and treatment: A focus on PI3K/AKT pathway

Despite significant advances in treatment modalities, millions of cancer-related deaths continue to occur annually, often as a consequence of developing resistance against the range of available chemotherapeutic drugs. Furthermore, available anti-cancer chemotherapeutic agents show limited efficacy, often have severe side effects, and are expensive. Thus, the discovery of pharmacological agents that do not have these disadvantages is necessary. Curcumin, a polyphenolic compound derived from turmeric (Curcumin longa L.), is one such agent that has been widely studied for its anti-inflammatory and/or anti-cancer effects. Curcumin exerts its anti-cancer effect by suppressing the initiation, progression, and metastasis of a variety of cancers and appears to inhibit carcinogenesis by affecting two main processes: angiogenesis and tumor growth. These anti-cancer effects are largely mediated via negative regulation of various transcription factors, growth factors, inflammatory cytokines, protein kinases, and other oncogenic molecules. The PI3K/AKT pathway is commonly activated in cancer initiation and progression. Considered to be the key signaling pathway, the phosphatidylinositol-3-kinase (PI3K)/protein kinase B (AKT) pathway therefore represents a key target for cancer therapeutics. In the current review, we focus upon curcumin's targeting of PI3K/AKT in different malignancies to effect inhibition of cancer development and progression.

Comparative Effects of Curcumin and Tetrahydrocurcumin on Dextran Sulfate Sodium-induced Colitis and Inflammatory Signaling in Mice

Background

Curcumin, a yellow ingredient of turmeric (Curcuma longa Linn, Zingiberaceae), has long been used in traditional folk medicine in the management of inflammatory disorders. Although curcumin has been reported to inhibit experimentally-induced colitis and carcinogenesis, the underlying molecular mechanisms remain largely unresolved.

Methods

Murine colitis was induced by dextran sulfate sodium (DSS) which mimics inflammatory bowel disease. Curcumin or tetrahydrocurcumin was given orally (0.1 or 0.25 mmol/kg body weight daily) for 7 days before and together with DSS administration (3% in tap water). Collected colon tissue was used for histologic and biochemical analyses.

Results

Administration of curcumin significantly attenuated the severity of DSS-induced colitis and the activation of NF-κB and STAT3 as well as expression of COX-2 and inducible nitric oxide synthase. In contrast to curcumin, its non-electrophilic analogue, tetrahydrocurcumin has much weaker inhibitory effects.

Conclusions

Intragastric administration of curcumin inhibited the experimentally induced murine colitis, which was associated with inhibition of pro-inflammatory signaling mediated by NF-κB and STAT3.

Targeting oncogenic transcription factors by polyphenols: A novel approach for cancer therapy

Inflammation is one of the major causative factor of cancer and chronic inflammation is involved in all the major steps of cancer initiation, progression metastasis and drug resistance. The molecular mechanism of inflammation driven cancer is the complex interplay between oncogenic and tumor suppressive transcription factors which include FOXM1, NF-kB, STAT3, Wnt/β- Catenin, HIF-1α, NRF2, androgen and estrogen receptors. Several products derived from natural sources modulate the expression and activity of multiple transcription factors in various tumor models as evident from studies conducted in cell lines, pre-clinical models and clinical samples. Further combination of these natural products along with currently approved cancer therapies added an additional advantage and they considered as promising targets for prevention and treatment of inflammation and cancer. In this review we discuss the application of multi-targeting natural products by analyzing the literature and future directions for their plausible applications in drug discovery.

Curcumin mediates anticancer effects by modulating multiple cell signaling pathways

Curcumin, a component of a spice native to India, was first isolated in 1815 by Vogel and Pelletier from the rhizomes of Curcuma longa (turmeric) and, subsequently, the chemical structure of curcumin as diferuloylmethane was reported by Milobedzka et al. [(1910) 43., 2163-2170]. Since then, this polyphenol has been shown to exhibit antioxidant, anti-inflammatory, anticancer, antiviral, antibacterial, and antifungal activities. The current review primarily focuses on the anticancer potential of curcumin through the modulation of multiple cell signaling pathways. Curcumin modulates diverse transcription factors, inflammatory cytokines, enzymes, kinases, growth factors, receptors, and various other proteins with an affinity ranging from the pM to the mM range. Furthermore, curcumin effectively regulates tumor cell growth via modulation of numerous cell signaling pathways and potentiates the effect of chemotherapeutic agents and radiation against cancer. Curcumin can interact with most of the targets that are modulated by FDA-approved drugs for cancer therapy. The focus of this review is to discuss the molecular basis for the anticancer activities of curcumin based on preclinical and clinical findings.

Structure-Activity Relationship of Curcumin: Role of the Methoxy Group in Anti-inflammatory and Anticolitis Effects of Curcumin

Curcumin, a dietary compound from turmeric, has beneficial effects on inflammatory diseases such as inflammatory bowel disease. Most previous studies have focused on the structure-activity relationship of the thiol-reactive α,β-unsaturated carbonyl groups of curcumin, so little is known about the roles of methoxy groups in biological activities of curcumin. Here we synthesized a series of curcumin analogues with different substitution groups (R = H-, Br-, Cl-, F-, NO₂-, CH₃-, and OH-) to replace the methoxy group and evaluated their biological effects in vitro and in vivo. Curcumin, Cur-OH, and Cur-Br (25 μM) suppressed 74.91 ± 0.88, 77.75 ± 0.89, and 71.75 ± 0.90% of LPS-induced NO production, respectively (P < 0.05). Similarly, these compounds also decreased iNOS expression, COX-2 expression, and NF-κB signaling in RAW 264.7 macrophage cells (P < 0.05). However, other analogues, especially Cur-NO₂, were inactive (P > 0.05). In the dextran sulfate sodium (DSS)-induced colitis mouse model, the Cur-Br analogue also showed a beneficial effect the same as curcumin (P < 0.05), whereas the Cur-NO₂ analogue had no effect in the animal model (P > 0.05). Together, the analogues have dramatically different effects on inflammation, supporting that the substitution group on the methoxy position plays an important role in the anti-inflammatory effects of curcumin. The methoxy group is a potential structural candidate for modification to design curcumin-based drugs for inflammatory diseases.

Natural Nuclear Factor Kappa Beta Inhibitors: Safe Therapeutic Options for Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is a chronic and debilitating condition classified as ulcerative colitis and Crohn's disease. IBD usually happens as result of immune dysfunction in the intestinal mucosa resulting in epithelial barrier dysfunction, which leads to exposure of the mucosal immune system to luminal antigenic material. This results in activation of inflammation, which is our bodies natural defense system; however, chronic inflammation leads to barrier dysfunction, which triggers a cycle of inflammation and further barrier dysfunction. This barrier breakdown results in the uncontrolled progression of IBD throughout the intestine. Despite the therapeutic advances made over the last decade, the current first line of treatment of IBD is limited to immunosuppressive and anti-inflammatory drugs, which need to be taken regularly and have significant side effects to the patients. Prolonged inflammation may increase the risk of intestinal malignancy. The role of nuclear factor kappa beta (NF-κβ) has been established in the regulation of innate immunity and inflammation. NF-κβ has also shown to be involved in critical events linking inflammation and cancer development. Recent investigations suggest that the NF-κβ signaling cascade may be the central mediator of gastrointestinal inflammation in IBD and malignancies including esophageal, gastric, and colorectal cancers. In this review, the therapeutic potential of natural NF-κβ inhibitors as safe therapeutic options for the treatment of IBD will be discussed.

Biological and therapeutic activities, and anticancer properties of curcumin

Curcumin (diferuloylmethane) is a polyphenol derived from the Curcuma longa plant. Curcumin has been used extensively in Ayurvedic medicine, as it is nontoxic and exhibits a variety of therapeutic properties, including antioxidant, analgesic, anti-inflammatory and antiseptic activities. Recently, certain studies have indicated that curcumin may exert anticancer effects in a variety of biological pathways involved in mutagenesis, apoptosis, tumorigenesis, cell cycle regulation and metastasis. The present study reviewed previous studies in the literature, which support the therapeutic activity of curcumin in cancer. In addition, the present study elucidated a number of the challenges concerning the use of curcumin as an adjuvant chemotherapeutic agent. All the studies reviewed herein suggest that curcumin is able to exert anti-inflammatory, antiplatelet, antioxidative, hepatoprotective and antitumor activities, particularly against cancers of the liver, skin, pancreas, prostate, ovary, lung and head neck, as well as having a positive effect in the treatment of arthritis.

Curcumin and inflammatory bowel disease: potential and limits of innovative treatments

Curcumin belongs to the family of natural compounds collectively called curcuminoids and it possesses remarkable beneficial anti-oxidant, anti-inflammatory, anti-cancer, and neuroprotective properties. Moreover it is commonly assumed that curcumin has also been suggested as a remedy for digestive diseases such as inflammatory bowel diseases (IBD), a chronic immune disorder affecting the gastrointestinal tract and that can be divided in two major subgroups: Crohn’s disease (CD) and Ulcerative Colitis (UC), depending mainly on the intestine tract affected by the inflammatory events. The chronic and intermittent nature of IBD imposes, where applicable, long-term treatments conducted in most of the cases combining different types of drugs. In more severe cases and where there has been no good response to the drugs, a surgery therapy is carried out. Currently, IBD-pharmacological treatments are generally not curative and often present serious side effects; for this reason, being known the relationship between nutrition and IBD, it is worthy of interesting the study and the development of new dietary strategy. The curcumin principal mechanism is the suppression of IBD inflammatory compounds (NF-κB) modulating immune response. This review summarizes literature data of curcumin as anti-inflammatory and anti-oxidant in IBD, trying to understand the different effects in CD e UC.