Curcumin suppresses gastric NF-κB activation and macromolecular leakage in Helicobacter pylori-infected rats

Natural foods resources and dietary ingredients for the amelioration of Helicobacter pylori infection

Helicobacter pylori (H. pylori) is a gastric-persistent pathogen that can cause peptic ulcer disease, gastric cancer, and mucosal-associated lymphoid tissue lymphoma. This pathogen is commonly treated with antibiotic-based triple or quadruple therapy. However, antibiotic therapy could result in the bacterial resistance, imbalance of gut microbiota, and damage to the liver and kidneys, etc. Therefore, there is an urgent need for alternative therapeutic strategies. Interestingly, natural food resources, like vegetables, fruits, spices, and edible herbs, have potent inhibitory effects on H. pylori. In this review, we systematically summarized these foods with supporting evidence from both animal and clinical studies. The results have indicated that natural foods may possess temporary inhibition effect on H. pylori rather than durable eradication, and may help to reduce H. pylori colonization, enhance the effect of antibiotics and modulate the host's immune response.

The Anti-Oxidant Curcumin Solubilized as Oil-in-Water Nanoemulsions or Chitosan Nanocapsules Effectively Reduces Helicobacter pylori Growth, Bacterial Biofilm Formation, Gastric Cell Adhesion and Internalization

The bacterium Helicobacter pylori (H. pylori) represents a major risk factor associated with the development of gastric cancer. The anti-oxidant curcumin has been ascribed many benefits to human health, including bactericidal effects. However, these effects are poorly reproducible because the molecule is extremely unstable and water insoluble. Here we solubilized curcumin as either nanoemulsions or chitosan nanocapsules and tested the effects on H. pylori. The nanoemulsions were on average 200 nm in diameter with a PdI ≤ 0.16 and a negative zeta potential (-54 mV), while the nanocapsules were 305 nm in diameter with a PdI ≤ 0.29 and a positive zeta potential (+68 mV). Nanocapsules were safer than nanoemulsions when testing effects on the viability of GES-1 gastric cells. Also, nanocapsules were more efficient than nanoemulsions at inhibiting H. pylori growth (minimal inhibitory concentration: 50 and 75 μM, respectively), whereby chitosan contributed to this activity. Importantly, both formulations effectively diminished H. pylori's adherence to and internalization by GES-1 cells, as well as biofilm formation. In summary, the demonstrated activity of the curcumin nanoformulations described here against H. pylori posit them as having great potential to treat or complement other therapies currently in use against H. pylori infection.

Antibacterial activity of curcumin and its essential nanoformulations against some clinically important bacterial pathogens: A comprehensive review

Multidrug-resistant bacterial infections can kill 700,000 individuals globally each year and is considered among the top 10 global health threats faced by humanity as the arsenal of antibiotics is becoming dry and alternate antibacterial molecule is in demand. Nanoparticles of curcumin exhibit appreciable broad-spectrum antibacterial activity using unique and novel mechanisms and thus the process deserves to be reviewed and further researched to clearly understand the mechanisms. Based on the antibiotic resistance, infection, and virulence potential, a list of clinically important bacteria was prepared after extensive literature survey and all recent reports on the antibacterial activity of curcumin and its nanoformulations as well as their mechanism of antibacterial action have been reviewed. Curcumin, nanocurcumin, and its nanocomposites with improved aqueous solubility and bioavailability are very potential, reliable, safe, and sustainable antibacterial molecule against clinically important bacterial species that uses multitarget mechanism such as inactivation of antioxidant enzyme, reactive oxygen species-mediated cellular damage, and inhibition of acyl-homoserine-lactone synthase necessary for quorum sensing and biofilm formation, thereby bypassing the mechanisms of bacterial antibiotic resistance. Nanoformulations of curcumin can thus be considered as a potential and sustainable antibacterial drug candidate to address the issue of antibiotic resistance.

The antimicrobial and immunomodulatory effects of Ionophores for the treatment of human infection

Ionophores are a diverse class of synthetic and naturally occurring ion transporter compounds which demonstrate both direct and in-direct antimicrobial properties against a broad panel of bacterial, fungal, viral and parasitic pathogens. In addition, ionophores can regulate the host-immune response during communicable and non-communicable disease states. Although the clinical use of ionophores such as Amphotericin B, Bedaquiline and Ivermectin highlight the utility of ionophores in modern medicine, for many other ionophore compounds issues surrounding toxicity, bioavailability or lack of in vivo efficacy studies have hindered clinical development. The antimicrobial and immunomodulating properties of a range of compounds with characteristics of ionophores remain largely unexplored. As such, ionophores remain a latent therapeutic avenue to address both the global burden of antimicrobial resistance, and the unmet clinical need for new antimicrobial therapies. This review will provide an overview of the broad-spectrum antimicrobial and immunomodulatory properties of ionophores, and their potential uses in clinical medicine for combatting infection.

Current Advances and Outlook in Gastric Cancer Chemoresistance: A Review

BACKGROUND

Surgical resection of the lesion is the standard primary treatment of gastric cancer. Unfortunately, most patients are already in the advanced stage of the disease when they are diagnosed with gastric cancer. Alternative therapies, such as radiation therapy and chemotherapy, can achieve only very limited benefits. The emergence of cancer drug resistance has always been the major obstacle to the cure of tumors. The main goal of modern cancer pharmacology is to determine the underlying mechanism of anticancer drugs.

OBJECTIVE

Here, we mainly review the latest research results related to the mechanism of chemotherapy resistance in gastric cancer, the application of natural products in overcoming the chemotherapy resistance of gastric cancer, and the new strategies currently being developed to treat tumors based on immunotherapy and gene therapy.

CONCLUSION

The emergence of cancer drug resistance is the main obstacle in achieving alleviation and final cure for gastric cancer. Mixed therapies are considered to be a possible way to overcome chemoresistance. Natural products are the main resource for discovering new drugs specific for treating chemoresistance, and further research is needed to clarify the mechanism of natural product activity in patients. .

Effects of Curcumin and Silymarin on the Shigella dysenteriae and Campylobacter jejuni In vitro

OBJECTIVE

Antimicrobial properties of silymarin and curcumin have been assessed against several infectious agents. The aim of this study was to investigate the anti-apoptotic and antibacterial effects of both compounds on the expression of genes among Shigella dysenteriae ATCC 12022 and Campylobacter jejuni subsp. jejuni strain ATCC 33560 standard strains.

METHODS

S. dysenteriae and C. jejuni standard strains were prepared from reference laboratory. Additionally, two clinical multidrug-resistant (MDR) isolates were adopted. Silymarin and curcumin stocks were purchased from Sigma Corporation (USA), and after preparation of dilutions (0.5-512 μg/ml), the minimum inhibitory concentration (MIC) and minimum bactericidal concentrations (MBC) were determined. Furthermore, the effect of 100 μg/ml of each compound was also evaluated on the expression of two gyrB and 16S rRNA housekeeping genes by quantitative real-time PCR (qRT-PCR).

RESULTS

Silymarin MIC and MBC were 512 μg/ml and > 512 μg/ml against S. dysenteriae and > 512μg/ml against C. jejuni standard strains, respectively. Moreover, curcumin MIC and MBC concentrations were 256 μg/ml and 512 μg/ml, respectively for ATCC strains. Silymarin down-expressed the expression of gyrB gene in S. dysenteriae and gyrB and 16srRNA gene in C. jejuni significantly (p < 0.05) compared with unexposed strains. In addition, curcumin could down-express the both gyrB and 16S rRNA genes in both strains significantly (p < 0.05). For two MDR clinical isolates, both MIC and MBC of compounds were > 512 μg/ml. Addition of 100 μg/ml curcumin and silymarin to ampicillin (10 μg/ml) lowered the MIC of MDR S. dysenteriae to 256 μg/ml and 512 μg/ml, respectively. However, no MIC change was observed with regard to C. jejuni.

CONCLUSION

In this study, curcumin and silymarin could inhibit the growth of S. dysenteriae and C. jejuni and 100 μg/ml sub-MIC levels exhibited the suppression of housekeeping genes. Combating pathogenic bacteria by compounds alternative to antibiotics in the era of antibiotic resistance is a proper strategy, though more studies using combinations of them are needed.

Effects of Curcumin and Its Analogues on Infectious Diseases

Infectious diseases (IDs) are life-threatening illnesses, which result from the spread of pathogenic microorganisms such as bacteria, viruses, fungi, and parasites. IDs are a major challenge for the healthcare systems around the world, leading to a wide variety of clinical manifestations and complications. Despite the capability of frontline-approved medications to partially prevent or mitigate the invasion and subsequent damage of IDs to host tissues and cells, problems such as drug resistance, insufficient efficacy, unpleasant side effects, and high expenses stand in the way of their beneficial applications. One strategy is to evaluate currently explored and available bioactive compounds as possible anti-microbial agents. The natural polyphenol curcumin has been postulated to possess various properties including anti-microbial activities. Studies have shown that it possess pleiotropic effects against bacterial- and parasitic-associating IDs including drug-resistant strains. Curcumin can also potentiate the efficacy of available anti-bacterial and anti-parasitic drugs in a synergistic fashion. In this review, we summarize the findings of these studies along with reported controversies of native curcumin and its analogues, alone and in combination, toward its application in future studies as a natural anti-bacterial and anti-parasitic agent.

Effect of Curcumin on Severity of Functional Dyspepsia: a Triple Blinded Clinical Trial

BackgroundFunctional dyspepsia is the main cause of upper abdominal discomfort affecting 5-10% of the world population. Despite various therapeutic approaches, up to 50% of patients with functional dyspepsia seek alternative treatments. In the present study we evaluated the effect of curcumin supplementation along with famotidine therapy on severity of functional dyspepsia. A total of 75 patients with functional dyspepsia according to Rome III criteria were allocated into intervention (N = 39) or control (N = 36) groups. The intervention group was treated with a combination of 500 mg curcumin and 40 mg famotidine daily for 1 month. The control group received placebo and 40 mg famotidine. Severity of dyspepsia symptoms was determined using the Hong Kong questionnaire at baseline, after the 1 month treatment and after a 1 month follow-up. The presence of H. pylori antigens in the stool samples was also investigated in all subjects. No significant difference was observed between intervention and control groups in biochemical indices, severity of dyspepsia and rate of H. pylori infection. A significant decrease was observed in severity of dyspepsia (p < 0.001) and rate of H. pylori infection (p = 0.004) immediately after the treatment and follow-up in the curcumin intervention group. This study indicated that curcumin therapy could be a favorable supplementation in the symptom management of functional dyspepsia. Moreover, curcumin could help efficient eradication of H. pylori in these patients.

Curcumin Nanocrystals: Production, Physicochemical Assessment, and In Vitro Evaluation of the Antimicrobial Effects against Bacterial Loading of the Implant Fixture

Background: This study aimed to prepare and study physicochemical properties as well as the antibacterial action of curcumin nanocrystals inside the implant fixture against Escherichia coli (E. coli), Staphylococcus aureus (S. aureus), and Enterococcus faecalis (E. faecalis). Methods: Curcumin nanocrystals were prepared via precipitation combined with the spray drying method. The produced curcumin nanocrystals were characterized by dynamic light scattering (DLS), scanning electron microscopy (SEM), powder X-ray diffraction (PXRD), and Fourier transform infrared spectroscopy (FTIR). Moreover, the in vitro antimicrobial effect of curcumin nanocrystals inside the implant fixture was assessed against E. coli, S. aureus, and E. faecalis. All implant-abutment assemblies were immersed in bacterial suspensions and were incubated at 24, 48, and 72 h. The contents of each implant were cultured to count the colony of bacteria at 37 °C for 24 h. Results: The prepared curcumin nanocrystals with a mean particle size of 95 nm and spherical morphology exhibited a removal rate of 99.99% for all bacteria. In addition, the colony-forming unit (CFU) of bacteria in exposure to nanocrystals significantly was reduced (p < 0.010) by increasing the time. Conclusions: Curcumin nanocrystals can be used inside the implant fixture as an antimicrobial agent in order to more stabilization of the implant.

The effect of snakehead fish extract supplementation to first-line eradication regimen on macrophage migration inhibitory factor (MIF) expression in rats induced by Helicobacter pylori infection

Objective:

This work was organized to assess macrophage migration inhibitory factor (MIF) expression in snakehead fish extract supplementation to first-line eradication regimen in rats induced by Helicobacter pylori infection.

Materials and methods:

A total of 28 manly rats were haphazardly isolated equally into four groups. Group-1 was the control negative, and groups-2–4 were H. pylori-infected groups. Group-2 was the control positive. Groups-3 and 4 were treated with first-line eradication regimen and first-line eradication regimen supplemented with snakehead fish extract, respectively. Immunoreactive scores (IRS) of MIF expression and eradication testing procedure were carried out. The comparison and difference between groups were analyzed by Kruskal–Wallis and post hoc Mann–Whitney U-test. A value of p < 0.05 was considered to be a limit of significance.

Results:

The average IRS of MIF expression in group-2 was the highest among other groups (p < 0.05). Group-4 (supplemented by snakehead fish extract) had a lower median value IRS of MIF expression compared to group-3 [1.0 (0.0–2.0) vs. 3.5 (2.0–6.0), p = 0.004].

Conclusion:

MIF expression was higher in rats induced by H. pylori infection. Snakehead fish extract supplementation to first-line eradication regimen significantly reduces more MIF expression compared to a single administration of first-line eradication regimen in rats induced by H. pylori infection.

Can Diet Modulate Helicobacter pylori-associated Gastric Pathogenesis? An Evidence-Based Analysis

Helicobacter pylori is involved in the pathogenesis of gastritis, peptic ulcer, and gastric cancer. The infection is prevalent in more than half of the world's population. Although the infection may lead to detrimental consequences, still the majority of the infected individuals only develop mild gastritis. Several factors are behind this paradoxical outcome including virulence of the infecting H. pylori strains, genetic background of the host, and factors related to lifestyle such as dietary habits. Among these, lifestyle including dietary factors was not in the limelight, until recently, as one of the important factors that could modulate H. pylori-linked gastric diseases. This review is directed to gather and elucidate the role of dietary components in augmenting or attenuating pathological processes initiated by H. pylori. Available evidence strongly supports the notion that the diet may play a critical role in defining the final outcome of H. pylori infection particularly if certain dietary components are taken on a regular basis for a long time. Despite a recent surge in research related to the role of dietary ingredients, further studies involving large-scale clinical trials are required to gain a better understanding of the precise role played by the dietary ingredients in H. pylori-associated pathogenesis.

Helicobacter pylori associated Asian enigma: Does diet deserve distinction?

Helicobacter pylori (H. pylori) is one of the most widespread infections in humans worldwide that chronically infects up to 50% of the world’s population. The infection is involved in the pathogenesis of chronic active gastritis, peptic ulcer, mucosa-associated lymphoid tissue lymphoma and gastric cancer, therefore, it has been classified as class I definite carcinogen by the World Health Organization. Despite the established etiological role of H. pylori, its actual distribution and association with related diseases is controversial and there is a large intercountry variation especially among Asian countries. H. pylori infection is more frequent in developing countries like India, Pakistan, and Bangladesh as compared to developed Asian countries like Japan, China and South Korea. However, the frequency of gastric cancer is comparatively lower in India, Pakistan, and Bangladesh with that of Japan, China and South Korea. Such phenomenon of clinical diversity, defined as enigma, is judged by genetic variability of the infecting H. pylori strains, differences in the host genetic background in various ethnic groups, and environmental factors such as dietary habits. Most of the studies have so far focused on the bacterial factor while environmental issues, including dietary components, were not given due attention as one of the factors related with H. pylori associated gastric carcinogenesis. The dietary factor has been suggested to play an important role in H. pylori related carcinogenesis, and in this respect several studies have corroborated the intake of various dietary components as modulatory factors for gastric cancer risk. In this review, such studies, from in vitro experiments to clinical trials, are being focused in detail with respect to enigma associated with H. pylori. It may be conceivably concluded from the available evidence that dietary factor can be a game changer in the scenario of Asian enigma, particularly in high risk population infected with virulent H. pylori strains, however further affirmation studies are desperately needed to achieve conclusive outcomes.

Curcumin as a potential therapeutic candidate for Helicobacter pylori associated diseases

Curcumin, a yellow pigment and principal polyphenolic Curcuminoid obtained from the turmeric rhizome Curcuma longa, is commonly used as a food-coloring agent. Studies suggest that curcumin has a wide range of beneficial properties e.g., anti-inflammatory, anti-oxidant, anti-cancer, anti-proliferative, anti-fungal and anti-microbial. These pleiotropic activities prompted several research groups to elucidate the role of curcumin in Helicobacter pylori (H. pylori) infection. This is the first review with this heading where we discussed regarding the role of curcumin as an anti-H. pylori agent along with its potential in other gastrointestinal diseases. Based on several in vitro, early cell culture, animal research and few pre-clinical trials, curcumin projected as a potential therapeutic candidate against H. pylori mediated gastric pathogenesis. This review sheds light on the anti-H. pylori effects of curcumin in different models with meticulous emphasis on its anti-oxidant, anti-inflammatory and anti-carcinogenic effects as well as some critical signaling and effecter molecules. Remarkably, non-toxic molecule curcumin fulfills the characteristics for an ideal chemopreventive agent against H. pylori mediated gastric carcinogenesis but the foremost challenge is to obtain the optimum therapeutic levels of curcumin, due to its low solubility and poor bioavailability. Further, we have discussed about the possibilities for improving its efficacy and bioavailability. Lastly, we concluded with the anticipation that in near future curcumin may be used to develop a therapeutic drug against H. pylori mediated gastric ailments through improved formulation or delivery systems, facilitating its enhanced absorption and cellular uptake.

Insights from the molecular docking of curcumin to the virulent factors of Helicobacter pylori

The domains of virulent (Ureα/β, VacA-p55, and CagA) factors of Helicobacter pylori play a pivotal role in developmental processes of numerous diseases including gastric cancer. The pharmacological role of curcumin indicates that it could regulate the signaling of virulent factors by interacting with active domains. However, the controlling mechanism of the curcumin interactions and the binding diversity on structural basis of virulent (Ureα/β, VacA-p55, and CagA) factors are unknown. Curcumin as therapeutic agent was filtered by using Lipinski rule׳s five and the druglikeness property for assessment of pharmacological properties. Here outcome of molecular docking presented the 3-D structure of curcumin complex, that interacted with especially conserved residues of target domains. The structure revealed that the curcumin complexation with domains of these proteins provided structural insight into the diverse nature of proteins (Ureα/β, VacA-p55, and CagA) recognition. In silico study elucidated that the broad specificity of curcumin was achieved by multiple binding mode mechanisms such as distinct hydrogen and hydrophobic interactions with involvement of binding energy. The higher score of curcumin in complexation with both subunits Ureα/β showed the stable binding, and less stability with VacA-p55 complexation with lower score. Curcumin exhibited good interaction with these targeted virulent factors, although extensive interactions of curcumin with Ureα/β subunits could have an important implication to prevent survival and colonisation of H. pylori in stomach.

Curcumin inhibits gastric inflammation induced by Helicobacter pylori infection in a mouse model

Helicobacter pylori (H. pylori) infection triggers a sequence of gastric alterations starting with an inflammation of the gastric mucosa that, in some cases, evolves to gastric cancer. Efficient vaccination has not been achieved, thus it is essential to find alternative therapies, particularly in the nutritional field. The current study evaluated whether curcumin could attenuate inflammation of the gastric mucosa due to H. pylori infection. Twenty-eight C57BL/6 mice, were inoculated with the H. pylori SS1 strain; ten non-infected mice were used as controls. H. pylori infection in live mice was followed-up using a modified 13C-Urea Breath Test (13C-UBT) and quantitative real-time polymerase chain reaction (PCR). Histologically confirmed, gastritis was observed in 42% of infected non-treated mice at both 6 and 18 weeks post-infection. These mice showed an up-regulation of the expression of inflammatory cytokines and chemokines, as well as of toll-like receptors (TLRs) and MyD88, at both time points. Treatment with curcumin decreased the expression of all these mediators. No inflammation was observed by histology in this group. Curcumin treatment exerted a significant anti-inflammatory effect in H. pylori-infected mucosa, pointing to the promising role of a nutritional approach in the prevention of H. pylori induced deleterious inflammation while the eradication or prevention of colonization by effective vaccine is not available.

Inhibition of β-catenin and STAT3 with a curcumin analog suppresses gastric carcinogenesis in vivo

BACKGROUND

Potent chemotherapy for advanced gastric cancer has not been completely established. Many molecularly targeted therapies are under investigation, but their therapeutic outcomes are not promising because they do not target specific and/or critical targets of gastric carcinogenesis. Although the molecular basis of gastric carcinogenesis remains poorly understood, nuclear localization of β-catenin was observed in approximately 50 % of gastric cancer specimens. Recent studies have suggested that activation of signal transducer and activator of transcription 3 (STAT3) contributes to gastric carcinogenesis in a mouse model. A newly synthesized curcumin analog has inhibitory potential against β-catenin and STAT3.

METHODS

Using a transgenic mouse model of gastric cancer in which β-catenin, cyclooxygenase 2, and microsomal prostaglandin E synthase 1 activation is induced, we examined a curcumin analog with the most enhanced potential for treating gastric cancer through oral administration. Inhibition of these targets was demonstrated using microarray and immunohistochemical analyses.

RESULTS

The curcumin analog GO-Y031 decreased the incidence of gastric carcinogenesis to 54.5 % of that of the control (50.0 % vs 91.7 %, p = 0.043), and tumor size was reduced to 51.6 % of that of the control (1.6 mm vs 3.1 mm, p = 0.03). β-Catenin and STAT3 levels were suppressed to 26.2 % (p = 0.00023) and 44.8 % (p = 0.025), respectively, of those of the control. Moreover, macrophage infiltration was suppressed with GO-Y031.

CONCLUSION

β-Catenin and STAT3 can be pharmacologically inhibited in vivo with a curcumin analog, which effectively inhibits β-catenin and STAT3.

Simple animal model of Helicobacter pylori infection

Helicobacter pylori (H. pylori) has become accepted as a human pathogen for the development of gastritis and gastroduodenal ulcer. To develop a simple rat model of chronic H. pylori infection, male Sprague-Dawley rats were pretreated with streptomycin suspended in tap water (5 mg/mL) for 3 d. The rats were inoculated by gavage at 1 mL/rat with H. pylori suspension (5 × 10⁸-5 × 10¹⁰ CFU/mL) twice daily at an interval of 4 h for three consecutive days. Two weeks after inoculation, rats were sacrificed and the stomachs were removed. Antral biopsies were performed for urease test and the stomachs were taken for histopathology. Successful H. pylori inoculation was defined as a positive urease test and histopathology. We reported a 69.8%-83.0% success rate for H. pylori infection using the urease test, and hematoxylin and eosin staining confirmed the results. Histopathological analysis detected bacteria along the mucous lining of the surface epithelium and crypt lumen and demonstrated mild to moderate gastric inflammation in successfully inoculated rats. We developed a simple rat model of chronic H. pylori infection for research into gastric microcirculatory changes and therapy with plant products.

Overview of the phytomedicine approaches against Helicobacter pylori

Helicobacter pylori (H. pylori) successfully colonizes the human stomach of the majority of the human population. This infection always causes chronic gastritis, but may evolve to serious outcomes, such as peptic ulcer, gastric carcinoma or mucosa-associated lymphoid tissue lymphoma. H. pylori first line therapy recommended by the Maastricht-4 Consensus Report comprises the use of two antibiotics and a proton-pomp inhibitor, but in some regions failure associated with this treatment is already undesirable high. Indeed, treatment failure is one of the major problems associated with H. pylori infection and is mainly associated with bacterial antibiotic resistance. In order to counteract this situation, some effort has been allocated during the last years in the investigation of therapeutic alternatives beyond antibiotics. These include vaccines, probiotics, photodynamic inactivation and phage therapy, which are briefly revisited in this review. A particular focus on phytomedicine, also described as herbal therapy and botanical therapy, which consists in the use of plant extracts for medicinal purposes, is specifically addressed, namely considering its history, category of performed studies, tested compounds, active principle and mode of action. The herbs already experienced are highly diverse and usually selected from products with a long history of employment against diseases associated with H. pylori infection from each country own folk medicine. The studies demonstrated that many phytomedicine products have an anti-H. pylori activity and gastroprotective action. Although the mechanism of action is far from being completely understood, current knowledge correlates the beneficial action of herbs with inhibition of essential H. pylori enzymes, modulation of the host immune system and with attenuation of inflammation.

In vitro synergistic effect of curcumin in combination with third generation cephalosporins against bacteria associated with infectious diarrhea

Diarrhea is one of the leading causes of morbidity and mortality in humans in developed and developing countries. Furthermore, increased resistance to antibiotics has resulted in serious challenges in the treatment of this infectious disease worldwide. Therefore, there exists a need to develop alternative natural or combination drug therapies. The aim of the present study was to investigate the synergistic effect of curcumin-1 in combination with three antibiotics against five diarrhea causing bacteria. The antibacterial activity of curcumin-1 and antibiotics was assessed by the broth microdilution method, checkerboard dilution test, and time-kill assay. Antimicrobial activity of curcumin-1 was observed against all tested strains. The MICs of curcumin-1 against test bacteria ranged from 125 to 1000 μg/mL. In the checkerboard test, curcumin-1 markedly reduced the MICs of the antibiotics cefaclor, cefodizime, and cefotaxime. Significant synergistic effect was recorded by curcumin-1 in combination with cefotaxime. The toxicity of curcumin-1 with and without antibiotics was tested against foreskin (FS) normal fibroblast and no significant cytotoxicity was observed. From our result it is evident that curcumin-1 enhances the antibiotic potentials against diarrhea causing bacteria in in vitro condition. This study suggested that curcumin-1 in combination with antibiotics could lead to the development of new combination of antibiotics against diarrhea causing bacteria.

A review on antibacterial, antiviral, and antifungal activity of curcumin

Curcuma longa L. (Zingiberaceae family) and its polyphenolic compound curcumin have been subjected to a variety of antimicrobial investigations due to extensive traditional uses and low side effects. Antimicrobial activities for curcumin and rhizome extract of C. longa against different bacteria, viruses, fungi, and parasites have been reported. The promising results for antimicrobial activity of curcumin made it a good candidate to enhance the inhibitory effect of existing antimicrobial agents through synergism. Indeed, different investigations have been done to increase the antimicrobial activity of curcumin, including synthesis of different chemical derivatives to increase its water solubility as well ass cell up take of curcumin. This review aims to summarize previous antimicrobial studies of curcumin towards its application in the future studies as a natural antimicrobial agent.

Helicobacter pylori and gastric cancer: Indian enigma

Helicobacter pylori (H. pylori) is a gram negative microaerophilic bacterium which resides in the mucous linings of the stomach. It has been implicated in the causation of various gastric disorders including gastric cancer. The geographical distribution and etiology of gastric cancer differ widely in different geographical regions and H. pylori, despite being labeled as a grade I carcinogen, has not been found to be associated with gastric cancer in many areas. Studies in Asian countries such as Thailand, India, Bangladesh, Pakistan, Iran, Saudi Arabian countries, Israel and Malaysia, have reported a high frequency of H. pylori infection co-existing with a low incidence of gastric cancer. In India, a difference in the prevalence of H. pylori infection and gastric cancer has been noted even in different regions of the country leading to a puzzle when attempting to find the causes of these variations. This puzzle of H. pylori distribution and gastric cancer epidemiology is known as the Indian enigma. In this review we have attempted to explain the Indian enigma using evidence from various Indian studies and from around the globe. This review covers aspects of epidemiology, the various biological strains present in different parts of the country and within individuals, the status of different H. pylori-related diseases and the molecular pathogenesis of the bacterium.

Novel Curcumin Diclofenac Conjugate Enhanced Curcumin Bioavailability and Efficacy in Streptococcal Cell Wall-induced Arthritis

Curcumin-diclofenac conjugate as been synthesized by esterification of phenolic group of curcumin with the acid moiety of diclofenac, and characterized by mass spectrometry, NMR, FTIR, DSC, thermogravimetric analysis and X-ray diffraction analysis. The relative solubility of curcumin-diclofenac conjugate, curcumin and diclofenac; stability of curcumin-diclofenac conjugate in intestinal extract; permeability study of curcumin-diclofenac conjugate using the everted rat intestinal sac method; stability of curcumin-diclofenac conjugate in gastrointestinal fluids and in vitro efficacy have been evaluated. In vivo bioavailability of curcumin-diclofenac conjugate and curcumin in Sprague-Dawley rats, and antiarthritic activity of curcumin-diclofenac conjugate, curcumin and diclofenac in modified streptococcal cell wall-induced arthritis model in Balb/c mice to mimic rheumatoid arthritis in humans have also been studied. In all of the above studies, curcumin-diclofenac conjugate exhibited enhanced stability as compared to curcumin; its activity was twice that of diclofenac in inhibiting thermal protein denaturation taken as a measure of in vitro antiinflammatory activity; it enhanced the bioavailability of curcumin by more than five folds, and significantly (P<0.01) alleviated the symptoms of arthritis in streptococcal cell wall-induced arthritis model as compared to both diclofenac and curcumin.

The molecular basis for the pharmacokinetics and pharmacodynamics of curcumin and its metabolites in relation to cancer

This review addresses the oncopharmacological properties of curcumin at the molecular level. First, the interactions between curcumin and its molecular targets are addressed on the basis of curcumin's distinct chemical properties, which include H-bond donating and accepting capacity of the β-dicarbonyl moiety and the phenylic hydroxyl groups, H-bond accepting capacity of the methoxy ethers, multivalent metal and nonmetal cation binding properties, high partition coefficient, rotamerization around multiple C-C bonds, and the ability to act as a Michael acceptor. Next, the in vitro chemical stability of curcumin is elaborated in the context of its susceptibility to photochemical and chemical modification and degradation (e.g., alkaline hydrolysis). Specific modification and degradatory pathways are provided, which mainly entail radical-based intermediates, and the in vitro catabolites are identified. The implications of curcumin's (photo)chemical instability are addressed in light of pharmaceutical curcumin preparations, the use of curcumin analogues, and implementation of nanoparticulate drug delivery systems. Furthermore, the pharmacokinetics of curcumin and its most important degradation products are detailed in light of curcumin's poor bioavailability. Particular emphasis is placed on xenobiotic phase I and II metabolism as well as excretion of curcumin in the intestines (first pass), the liver (second pass), and other organs in addition to the pharmacokinetics of curcumin metabolites and their systemic clearance. Lastly, a summary is provided of the clinical pharmacodynamics of curcumin followed by a detailed account of curcumin's direct molecular targets, whereby the phenotypical/biological changes induced in cancer cells upon completion of the curcumin-triggered signaling cascade(s) are addressed in the framework of the hallmarks of cancer. The direct molecular targets include the ErbB family of receptors, protein kinase C, enzymes involved in prostaglandin synthesis, vitamin D receptor, and DNA.

Synergistic antibacterial effect of curcumin against methicillin-resistant Staphylococcus aureus

Methicillin-resistant Staphylococcus aureus (MRSA) are spread among infected patients, with infection rates increasing at an alarming rate. Furthermore, increased resistance to antibiotics has resulted in serious challenges in the treatment of infectious diseases worldwide. Under the selection pressure of exposure to antibiotics, microorganisms evolve to survive against the new conditions imposed by therapy. Therefore, there exists a need to develop alternative natural or combination drug therapies. Curcumin (CCM), a natural polyphenolic flavonoid isolated from the rhizome of a plant, Curcuma longa Linné., has been found to possess many beneficial biological activities. The aim of this study was to investigate the synergistic effect of curcumin and antibiotics as well as to determine the antibacterial activity of CCM against specific MRSA strains. The antibacterial activity of CCM was assessed by the broth microdilution method (by calculating the minimal inhibitory concentration [MIC]), checkerboard dilution test, and time-kill assay. Antimicrobial activity of CCM was observed against all tested strains. The MICs of CCM against 10 strains of S. aureus ranged from 125 to 250 μg/ml. In the checkerboard test, CCM markedly reduced the MICs of the antibiotics oxacillin (OXI), ampicillin (AMP), ciprofloxacin (CIP), and norfloxacin (NOR) used against MRSA. The time-kill curves showed that a combined CCM and OXI treatment reduced the bacterial counts below the lowest detectable limit after 24h. This study suggested that CCM reduced the MICs of several antibiotics tested, notably of OXI, AMP, CIP, and NOR, and that CCM in combination with antibiotics could lead to the development of new combination of antibiotics against MRSA infection.

Curcumin attenuated paracetamol overdose induced hepatitis

AIM

To investigate whether curcumin could attenuate hepatitis in mice with paracetamol overdose.

METHODS

Male mice were divided into four groups. Group 1 (control, n = 8); was fed with distilled water; Group 2 [N-acetyl-P-aminophenol (APAP), n = 8]; was fed with a single dose of 400 mg/kg APAP dissolved in distilled water; Group 3 [APAP + curcumin (CUR) 200, n = 8], was fed with a single dose of 400 mg/kg APAP and 200 mg/kg CUR; Group 4 (APAP + CUR 600, n = 8), was fed with a single dose of 400 mg/kg APAP and 600 mg/kg CUR. Twenty-four hours later, the liver was removed to examine hepatic glutathione (GSH), hepatic malondialdehyde (MDA), and histopathologically. Then whole blood was withdrawn from heart to determine transaminase (serum glutamic oxaloacetic transaminase and serum glutamic pyruvic transaminase) and inflammatory cytokines [interleukin (IL)-12 and IL-18] levels by enzyme linked immunosorbent assay.

RESULTS

Serum transaminase, hepatic MDA, and inflammatory cytokines increased significantly in the APAP compared with the control group. Curcumin supplementation in APAP + CUR 200 and APAP + CUR 600 groups significantly decreased these parameters compared with the APAP group. The level of GSH decreased significantly in the APAP compared with the control group. Curcumin supplementation in APAP + CUR 200 and APAP + CUR 600 groups significantly increased these parameters compared with the APAP group. The histological appearance of the liver in the control group showed normal. In the APAP-treated group, the liver showed extensive hemorrhagic hepatic necrosis at all zones. Curcumin supplementation in APAP + CUR 200 and APAP + CUR 600 groups, caused the liver histopathology to improve. In the APAP + CUR 200 group, the liver showed focal necrosis and but the normal architecture was well preserved in APAP + CUR 600 group.

CONCLUSION

APAP overdose can cause liver injury. Results indicate that curcumin prevents APAP-induced hepatitis through the improvement of liver histopathology by decreased oxidative stress, reduced liver inflammation, and restoration of GSH.

Protective mechanism of curcumin against Vibrio vulnificus infection

Curcumin, a natural polyphenolic flavonoid extracted from the rhizome of Curcuma longa L., has many beneficial biological activities. However, there are relatively few reports of the effects of curcumin on pathogen infections. This study examined the effect of curcumin on a Vibrio vulnificus infection. The cytotoxicity of V. vulnificus to HeLa cells was significantly inhibited by curcumin (at 10 or 30 μM). To further examine the inhibitory mechanism of curcumin against V. vulnificus-mediated cytotoxicity, the level of bacterial growth, bacterial motility, cell adhesion, RTX toxin expression and host cell reactions were evaluated. Curcumin inhibited V. vulnificus growth in HI broth. Curcumin inhibited both bacterial adhesion and RTX toxin binding to the host cells, which can be considered the major protective mechanisms for the decrease in V. vulnificus cytotoxicity. Curcumin also inhibited host cell rounding and actin aggregation, which are the early features of cell death caused by V. vulnificus. In addition, curcumin decreased the V. vulnificus-induced NF-κB translocation in HeLa cells. Finally, curcumin protected mice from V. vulnificus-induced septicemia. In conclusion, curcumin may be an alternative antimicrobial agent against fatal bacterial infections.

Clinical significance of nuclear factor κB expression in primary gastrointestinal diffuse large B-cell lymphoma

AIM: To investigate the clinical significance of nuclear factor κB (NF-κB) expression in primary gastrointestinal diffuse large B-cell lymphoma (PGI-DLBCL).

METHODS: Immunohistochemical staining was used to detect the expression of CD10, Bcl-6, Mum-1 and NF-κB p65 in PGI-DLBCL. The relationship of NF-κB p65 expression with tumor subtype, biological behavior and prognosis was analyzed.

RESULTS: Of 54 cases of PGI-DLBCL detected, 28% were positive for CD10, 69% positive for Bcl-6, and 81% positive for Mum-1; 19 were classified as germinal center B-cell-like (GCB) subtype, and 35 as activated B-cell like (ABC) subtype. The positive rate of NF-κB p65 expression in PGI-DLBCL was 72% (39/54). The positive rate of NF-κB p65 expression was significantly higher in ABC-DLBCL than in GCB-DLBCL (74.4% vs 25.6%, P < 0.05). NF-κB p65 expression was correlated with extranodal invasion site in PGI-DLBCL (P < 0.05). The overall survival time of NF-κB p65-negative PGI-DLBCL patients was longer than that of NF-κB p65-positive ones (45.8 mo ± 35.9 mo vs 20.3 mo ± 29.3 mo, P < 0.05).

CONCLUSION: NF-κB p65 expression was positively correlated with the subtype, development, and invasion of PGI-DLBCL. NF-κB p65 can be used as a prognostic factor for PGI-DLBCL and may represent a new molecular target for the therapy of GI-DLBCL.

In vitro study and biocompatibility of calcined mesoporous silica microparticles in mouse lung

We report on the pneumatocyte structure and function of mouse lung specimens exposed in vitro to two calcined mesoporous silica particles, MCM41-cal (spheres, ∼300 to 1000 nm in diameter) and SBA15-cal (irregular rods averaging ∼500 nm in diameter and ∼1000 nm in length). These mesoporous silica particles are in consideration for potential medical application as delivery vehicles for genes, drugs, and bio-imagers. In the study, lung specimens (about 10 mg each) were excised from male Balb/c mice, immediately immersed in Krebs-Henseleit buffer, ice-cold, and continuously gassed with O(2):CO(2) (95:5). The samples were incubated at 37°C in the same buffer with and without 200 μg/mL MCM41-cal or SBA15-cal for 5-14 h. The tissues were then rinsed thoroughly and processed for light and electron microscopy. Normal alveolar morphology was evident in all the studied specimens. There was no significant difference in the number of apoptotic cells between the treated and untreated samples. Despite their relatively large sizes, the particles were abundantly present in pneumocytes, macrophages, endothelial cells, fibroblasts, and interstitium. They were seen in different areas of the cytoplasm, suggesting intracellular movements. Their presence did not appear to disturb cellular configuration or micro-organelles. Due to their rigidity and surface charges, some were firmly attached to (indenting) the nuclear membrane. The rate of respiration (cellular mitochondrial O(2) consumption, in μM O(2)/min/mg) in specimens exposed to 200 μg/mL particles for up to 12 h was the same as untreated specimens. These findings confirm "reasonable" bioavailability and biocompatibility of calcined mesoporous silicas with mouse lung within at least 5-14 h of exposure time.