Adjunctive Therapy with Curcumin for Peptic Ulcer: a Randomized Controlled Trial

A systematic review of the efficacy and safety of turmeric in the treatment of digestive disorders

Turmeric has been gaining popularity as a treatment option for digestive disorders, although a rigorous synthesis of efficacy has not been conducted. This study aimed to summarize the evidence for the efficacy and safety of turmeric in the treatment of digestive disorders, including inflammatory bowel diseases (IBD), irritable bowel syndrome (IBS), dyspepsia, gastroesophageal reflux disease, and peptic ulcers. Literature searches were conducted in Medline, EMBASE, AMED, the Cochrane Central Register of Control Trials, and Dissertation Abstracts from inception to November 15, 2021. Dual independent screening of citations and full texts was conducted and studies meeting inclusion criteria were retained: randomized controlled trials (RCT) and comparative observational studies evaluating turmeric use in people of any age with one of the digestive disorders of interest. Extraction of relevant data and risk of bias assessments were performed by two reviewers independently. Meta-analysis was not conducted due to high heterogeneity. From 1136 citations screened, 26 eligible studies were retained. Most studies were assessed to have a high risk of bias, and many had methodological limitations. Descriptive summaries suggest that turmeric is safe, with possible efficacy in patients with IBD or IBS, but its effects were inconsistent for other conditions. The efficacy of turmeric in digestive disorders remains unclear due to the high risk of bias and methodological limitations of the included studies. Future studies should be designed to include larger sample sizes, use rigorous statistical methods, employ core outcome sets, and adhere to reporting guidance for RCTs of herbal interventions to facilitate more meaningful comparisons and robust conclusions.

Advancing Gastrointestinal Health: Curcumin's Efficacy and Nanopreparations

Curcumin (CCM) is a polyphenol compound extracted from the turmeric rhizome. It has various biological activities, including antibacterial, anti-inflammatory, anti-cancer, and antioxidant. Due to its diverse activities, it is often used by researchers to study the therapeutic effects on various diseases. However, its poor solubility leads to poor bioavailability, and it is necessary to increase the water solubility with the help of carriers to improve the therapeutic effect. Gastrointestinal disease is a major global health problem that continues to affect human health. In this review, we have summarized the possible mechanism and therapeutic effect of CCM in various gastrointestinal diseases, and the improvement in the curative effect of CCM with nanopreparation. Finally, we concluded that there have been many clinical trials of CCM in combination with other drugs for the treatment of gastrointestinal disease, but so far, few have used CCM nanomaterials for treatment. Although in vitro and preclinical experiments have shown that nanopreparations can improve the efficacy of CCM, there are still insufficient studies on the safety of carriers.

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.

PDE5 inhibitors and gastric mucosa: implications for the management of peptic ulcer disease

Peptic ulcer disease (PUD) continues to be a cause of significant morbidity and mortality worldwide. Almost two-thirds of PUD cases are asymptomatic. In symptomatic patients, epigastric pain is the most common presenting symptom of PUD, which is manifested by nausea, abdominal fullness, bloating, and dyspepsia. Most PUD cases are associated with the use of COX inhibitors or Helicobacter pylori infection, or both. The traditional management of PUD includes the use of proton pump inhibitors to reduce the gastric acid secretion and antibacterial drugs to combat H. pylori. Timely diagnosis and treatment of PUD are vital to reduce the risk of associated morbidity and mortality, as is prevention of PUD among patients at high risk, including COX inhibitors users and those infected with H. pylori. PDE5 inhibitors have been used for the management of erectile dysfunction and pulmonary hypertension for decades. In recent years, studies have mentioned tremendous pleiotropic effects of PDE5 inhibitors on gastrointestinal, urogenital, musculoskeletal, reproductive, cutaneous, and neurologic disorders. Recent data shows that PDE5 inhibition augments gastric mucosa protection, and here, we review the most recent findings regarding the use of PDE5 inhibitors for the prevention and management of PUD.

Effect of curcumin on inflammatory biomarkers and iron profile in patients with premenstrual syndrome and dysmenorrhea: A randomized controlled trial

Premenstrual syndrome (PMS) and primary dysmenorrhea are common gynecological problems and inflammation may have a role in their etiology. Curcumin is a polyphenolic natural product for which there is increasing evidence of anti-inflammatory and iron chelation effects. This study assessed the effects of curcumin on inflammatory biomarkers and iron profile in young women with PMS and dysmenorrhea. A sample of 76 patients was included in this triple-blind, placebo-controlled clinical trial. Participants were randomly allocated to curcumin (n = 38) and control groups (n = 38). Each participant received one capsule (500 mg of curcuminoid+ piperine, or placebo) daily, from 7 days before until 3 days after menstruation for three consecutive menstrual cycles. Serum iron, ferritin, total iron-binding capacity (TIBC) and high-sensitivity C-reactive protein (hsCRP), as well as white blood cell, lymphocyte, neutrophil, platelet counts, mean platelet volume (MPV) and red blood cell distribution width (RDW), were quantified. Neutrophil: lymphocyte ratio (NLR), platelet: lymphocyte ratio (PLR), and RDW: platelet ratio (RPR) were also calculated. Curcumin significantly decreased the median (interquartile range) serum levels of hsCRP [from 0.30 mg/L (0.0-1.10) to 0.20 mg/L (0.0-1.3); p = 0.041] compared with placebo, but did not show any difference for neutrophil, RDW, MPV, NLR, PLR and RPR values (p > 0.05). The treatment schedule was well-tolerated, and none of markers of iron metabolism statistically changed after the intervention in the curcumin group (p > 0.05). Curcumin supplementation may have positive effects on serum hsCRP, a marker of inflammation, with no any changes on iron homeostasis in healthy women with PMS and dysmenorrhea.

Role of Turmeric and Curcumin in Prevention and Treatment of Chronic Diseases: Lessons Learned from Clinical Trials

Turmeric (Curcuma longa) has been used for thousands of years for the prevention and treatment of various chronic diseases. Curcumin is just one of >200 ingredients in turmeric. Almost 7000 scientific papers on turmeric and almost 20,000 on curcumin have been published in PubMed. Scientific reports based on cell culture or animal studies are often not reproducible in humans. Therefore, human clinical trials are the best indicators for the prevention and treatment of a disease using a given agent/drug. Herein, we conducted an extensive literature survey on PubMed and Scopus following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The keywords "turmeric and clinical trials" and "curcumin and clinical trials" were considered for data mining. A total of 148 references were found to be relevant for the key term "turmeric and clinical trials", of which 70 were common in both PubMed and Scopus, 44 were unique to PubMed, and 34 were unique to Scopus. Similarly, for the search term "curcumin and clinical trials", 440 references were found to be relevant, of which 70 were unique to PubMed, 110 were unique to Scopus, and 260 were common to both databases. These studies show that the golden spice has enormous health and medicinal benefits for humans. This Review will extract and summarize the lessons learned about turmeric and curcumin in the prevention and treatment of chronic diseases based on clinical trials.

Curcumin Supplementation and Human Disease: A Scoping Review of Clinical Trials

Medicinal properties of turmeric (Curcuma longa L.), a plant used for centuries as an anti-inflammatory, are attributed to its polyphenolic curcuminoids, where curcumin predominates. Although "curcumin" supplements are a top-selling botanical with promising pre-clinical effects, questions remain regarding biological activity in humans. To address this, a scoping review was conducted to assess human clinical trials reporting oral curcumin effects on disease outcomes. Eight databases were searched using established guidelines, yielding 389 citations (from 9528 initial) that met inclusion criteria. Half focused on obesity-associated metabolic disorders (29%) or musculoskeletal disorders (17%), where inflammation is a key driver, and beneficial effects on clinical outcomes and/or biomarkers were reported for most citations (75%) in studies that were primarily double-blind, randomized, and placebo-controlled trials (77%, D-RCT). Citations for the next most studied disease categories (neurocognitive [11%] or gastrointestinal disorders [10%], or cancer [9%]), were far fewer in number and yielded mixed results depending on study quality and condition studied. Although additional research is needed, including systematic evaluation of diverse curcumin formulations and doses in larger D-RCT studies, the preponderance of current evidence for several highly studied diseases (e.g., metabolic syndrome, osteoarthritis), which are also clinically common, are suggestive of clinical benefits.

Curcumin-piperine co-supplementation and human health: A comprehensive review of preclinical and clinical studies

Curcumin is extracted from the rhizomes Curcuma longa L. It is known for its anti-inflammatory and anti-oxidant activities. Despite its safety and potential for use against various diseases, curcumin's utility is restricted due to its low oral bioavailability. Co-administration of curcumin along with piperine could potentially improve the bioavailability of curcumin. The present review aimed to provide an overview of the efficacy and safety of curcumin-piperine co-supplementation in human health. The findings of this comprehensive review show the beneficial effects of curcumin-piperine in improving glycemic indices, lipid profile and antioxidant status in diabetes, improving the inflammatory status caused by obesity and metabolic syndrome, reducing oxidative stress and depression in chronic stress and neurological disorders, also improving chronic respiratory diseases, asthma and COVID-19. Further high-quality clinical trial studies are needed to firmly establish the clinical efficacy of the curcumin-piperine supplement.

Effect of polyphenol compounds on Helicobacter pylori eradication: a systematic review with meta-analysis

OBJECTIVES

Polyphenol compounds are classified as organic compounds with phenolic units exhibiting a variety of biological functions. This meta-analysis aims to assess the efficacy and safety of polyphenol compounds (curcumin, cranberry, garlic, liquorice and broccoli) in eradicating Helicobacter pylori.

DESIGN

Systematic review and meta-analysis.

METHODS

Literature searches were conducted on PubMed, Embase, The Cochrane Library, Web of Science, Medline, Chinese National Knowledge Infrastructure database, Chinese Scientific Journal Database and Wan Fang database from inception to January 2022. All randomised controlled trials comparing polyphenol compounds with the placebo or used as an adjunct treatment are included in this meta-analysis.The treatment effect for dichotomous outcomes was assessed using risk ratio (RR), while for continuous outcomes, mean differences both with 95% CIs, were used. Subgroup analyses were carried out for different treatment schemes and polyphenol compound species.

RESULTS

12 trials were included in the meta-analysis. The total eradication rate of H.pylori in the polyphenol compounds group was higher than in the group without polyphenol compounds. Statistical significance was also observed (RR 1.19, 95% CI 1.03 to 1.38, p=0.02). The most frequent adverse effects of polyphenol compounds included diarrhoea, headache and vomiting. However, there were no differences regarding side effects between the two groups (RR 1.47, 95% CI 0.83 to 2.58, p=0.18). In subgroup analyses, the H.pylori eradication rate regimens with polyphenols therapy was superior to that of regimens without polyphenols therapy in the polyphenols versus placebo subgroup (RR 4.23, 95% CI 1.38 to 12.95, p=0.01), polyphenols plus triple therapy versus triple therapy subgroup (RR 1.11, 95% CI 1.01 to 1.22, p=0.03).

CONCLUSION

Polyphenol compounds can improve H.pylori eradication rates. Polyphenol compounds plus standard triple therapy can significantly improve the eradication. However, no evidence of a higher incidence of side effects could be found.

PROSPERO REGISTRATION NUMBER

CRD42022307477.

Curcuma longa Linn versus omeprazole in treatment of functional dyspepsia: A randomized, double-blind, placebo-controlled trial

BACKGROUND AND AIMS

Functional dyspepsia (FD) is a common problem in gastroenterology practice. The study aimed to compare the efficacy of Curcuma longa Linn versus omeprazole and placebo among patients diagnosed with FD.

METHODS

From November 2017 to November 2018, patients diagnosed with FD according to ROME IV criteria were enrolled. Patients were randomized into curcumin, omeprazole, or placebo groups. The Severity of Dyspepsia Assessment (SODA) was used to evaluate clinical effectiveness after 2 and 4 weeks. Health-related quality of life was assessed using the EuroQol-5 Dimension questionnaire.

RESULTS

A total of 132 patients were randomized. Forty-five, 43, and 44 patients were in the curcumin, omeprazole, and placebo groups, respectively. At 4 weeks, the mean SODA score change of pain and non-pain symptoms decreased in the curcumin group compared with the placebo group (pain -16.98 ± 8.09 vs -10.53 ± 4.43; P < 0.001, non-pain -7.96 ± 3.41 vs -6.05 ± 3.03; P < 0.008). No significant difference was observed between curcumin and omeprazole groups (pain -16.98 ± 8.09 vs -14.69 ± 6.41; P = 0.302, non-pain -7.96 ± 3.41 vs -7.07 ± 2.27; P = 0.486). The mean change of the SODA satisfaction score at 4 weeks was higher in the curcumin group compared with the omeprazole group but without statistical significance (9.17 ± 3.88 vs 8.63 ± 3.89, P = 1). The mean change of EQ-5D index at 4 weeks was highest in the curcumin group but not statistically different from other groups (0.12 ± 0.13 vs 0.09 ± 0.10 vs 0.07 ± 0.05; P = 0.055).

CONCLUSION

Curcuma longa Linn can improve dyspeptic symptoms, improve quality of life, and provide satisfaction equivalent to omeprazole in treatment of FD.

Safety Aspects of the Use of Isolated Piperine Ingested as a Bolus

Piperine is a natural ingredient of Piper nigrum (black pepper) and some other Piper species. Compared to the use of pepper for food seasoning, piperine is used in food supplements in an isolated, concentrated form and ingested as a bolus. The present review focuses on the assessment of the possible critical health effects regarding the use of isolated piperine as a single ingredient in food supplements. In human and animal studies with single or short-term bolus application of isolated piperine, interactions with several drugs, in most cases resulting in increased drug bioavailability, were observed. Depending on the drug and extent of the interaction, such interactions may carry the risk of unintended deleteriously increased or adverse drug effects. Animal studies with higher daily piperine bolus doses than in human interaction studies provide indications of disturbance of spermatogenesis and of maternal reproductive and embryotoxic effects. Although the available human studies rarely reported effects that were regarded as being adverse, their suitability for detailed risk assessment is limited due to an insufficient focus on safety parameters apart from drug interactions, as well as due to the lack of investigation of the potentially adverse effects observed in animal studies and/or combined administration of piperine with other substances. Taken together, it appears advisable to consider the potential health risks related to intake of isolated piperine in bolus form, e.g., when using certain food supplements.

N-Doped carbon dots for the fluorescence and colorimetry dual-mode detection of curcumin

Nitrogen doped carbon dots (N-CDs) were synthesized by a one-step hydrothermal method with dopamine and ethylenediamine. The as-prepared N-CDs were characterized via transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), fluorescence spectrophotometer, UV-Vis spectrophotometry and Fourier transform infrared spectroscopy (FTIR). The average particle dimension of the as-prepared N-CDs was 2.68 nm, and the best excitation and emission wavelengths were 405 nm and 535 nm, separately. N-CDs exhibits excellent selectivity and sensitivity to detect the curcumin (Cur), attaining a wider linear range of 97.5 nM-67.9 μM and a limit of detection (LOD) of as low as 94 nM. Interestingly, N-CDs can also give responsive signals of a visible colour change (yellow to red). Moreover, a novel fluorescent/colorimetric dual-mode method has been successfully employed for the determination of Cur in real samples with good recoveries (94%-110%) and precision (RSD = 0.3-2.9%).

Vegetable Extracts and Nutrients Useful in the Recovery from Helicobacter pylori Infection: A Systematic Review on Clinical Trials

Helicobacter pylori (H. pylori) infections affect almost half of the world’s population, with gradually increasing incidence in developed countries. Eradication of H. pylori may provide significant benefits to the affected individual by healing a number of gastrointestinal and extra-digestive disorders. But due to increased microbial resistance and lack of patient adherence to the therapy, the eradication rate of H. pylori is below 80% with current pharmacological therapies. The usage of botanicals for their therapeutic purposes and medicinal properties have been increased in last decades. They can be use as alternative H. pylori treatments, especially against drug-resistant strains. Epidemiological studies have revealed that people with lower vegetable and micronutrient intake may be at increased risk of H. pylori infection. We have undertaken a review of clinical trials to evaluate the efficacy of vegetable extracts and micronutrients in patients with H. pylori. Various databases, such as Google Scholar, PubMed, Scopus, Web of Science, and the Cochrane Library, were searched for the articles published in English. A total of 24 clinical studies (15 for vegetable extracts and 9 for micronutrients) were selected to be reviewed and summarized in this article. Vegetable extracts (Broccoli sprouts, curcumin, Burdock complex, and Nigella sativa) and micronutrients (vitamin C and E) were not found to be as effective as single agents in H. pylori eradication, rather their efficacy synergized with conventional pharmacological therapies. Conversely, GutGard was found to be significantly effective as a single agent when compared to placebo control.

A Systematic Review of the Clinical Use of Curcumin for the Management of Gastrointestinal Diseases

Gastrointestinal (GI) diseases are highly prevalent worldwide, with considerable morbidity and mortality. Curcumin has been used for many years as a plant-derived product for the management of various conditions such as abdominal pain and poor digestion. This systematic review was undertaken with the aim of investigating the effect of curcumin or turmeric supplementation on GI diseases. A comprehensive systematic search was conducted in PubMed, Scopus, Web of Science and Google Scholar up to March 2020 to identify clinical trials assessing the effect of curcumin/turmeric alone or in combination with other herbs or nutrients on GI diseases. Twenty-one studies comprising 1478 GI patients were included in the study. Four out of seven studies showed a beneficial effect of curcumin/turmeric supplementation on irritable bowel syndrome (IBS) and six out of seven showed positive effects of these herbs on ulcerative colitis. Two out of four studies highlighted the potential role of curcumin/turmeric in eradication of H. pylori infection. Both studies conducted on peptic ulcer disease and two out of four studies performed on Crohn's disease demonstrated positive effects of curcumin/turmeric supplementation. One study showed curcumin supplementation had no effect on familial adenomatous polyposis. However, in another study, curcumin had favorable effects on proctosigmoiditis. Nine studies reported some minor adverse effects. The results of this systematic review suggest a beneficial effect of curcumin/turmeric supplementation on the management of GI diseases. More randomized clinical controlled trials are needed to confirm these results.

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.

Efficacy of Curcuma longa in treatment of postprandial distress syndrome: An open-label randomized-controlled trial

Background: Proton pump inhibitors are effective for functional dyspepsia but ineffective in relieving postprandial distress syndrome. Curcuma longa might be effective for postprandial distress syndrome. The objective of this study was to compare the efficacy of Curcuma longa and simethicone for postprandial distress syndrome in an open-label randomized-controlled trial.

Methods: This trial was conducted between July 2018 and February 2019. In total, 78 patients were randomly assigned to receive 4 weeks of treatment with 750 or 1,500 mg oral Curcuma longa per day or 240 mg simethicone per day. The patients assessed their symptoms using the dyspepsia Global Overall Symptom scale at baseline, week 2, and week 4. After stopping medication for 2 weeks, the patients assessed recurrent symptoms and day of recurrence by themselves at the end of week 6.

Results: In total, 78 patients underwent randomization (27 in 750 mg Curcuma longa, 26 in 1500 mg Curcuma longa, and 25 in simethicone groups). After 2 weeks, there were no significant differences in all mean changes of symptoms scores (95%CI) of postprandial distress syndrome [-4.1 (-4.5, -2.6) vs -4.3 (-5.2, -3.3) vs -4.2 (-4.8, -3.5), P=0.954]. Over a period of 4 weeks, the reduction in mean scores was greater among participants receiving simethicone (although not statistically significant) compared with two intervention groups [-4.6 (-5.7, -3.6) vs -5.4 (-6.6, -4.1) vs -6.2 (-7.2, -5.2), P=0.122]. The rate of recurrence was significantly lower in simethicone than the two Curcuma longa groups (42.9 vs 45.5 vs 13.6%, P=0.047). There was no serious adverse event reported in all three groups.

Conclusions: Curcuma longa had a similar effect on treatment outcomes to simethicone after 2 and 4 weeks, but the recurrence rate of symptoms was significantly higher without serious adverse events.

Registration: Registered with the Thai Clinical Trials Registry on 31 January 2018; TCTR20180131001.

Curcumin: A Potent Protectant against Esophageal and Gastric Disorders

Turmeric obtained from the rhizomes of Curcuma longa has been used in the prevention and treatment of many diseases since the ancient times. Curcumin is the principal polyphenol isolated from turmeric, which exhibits anti-inflammatory, antioxidant, antiapoptotic, antitumor, and antimetastatic activities. The existing evidence indicates that curcumin can exert a wide range of beneficial pleiotropic properties in the gastrointestinal tract, such as protection against reflux esophagitis, Barrett’s esophagus, and gastric mucosal damage induced by nonsteroidal anti-inflammatory drugs (NSAIDs) and necrotizing agents. The role of curcumin as an adjuvant in the treatment of a Helicobacter pylori infection in experimental animals and humans has recently been proposed. The evidence that this turmeric derivative inhibits the invasion and proliferation of gastric cancer cells is encouraging and warrants further experimental and clinical studies with newer formulations to support the inclusion of curcumin in cancer therapy regimens. This review was designed to analyze the existing data from in vitro and in vivo animal and human studies in order to highlight the mechanisms of therapeutic efficacy of curcumin in the protection and ulcer healing of the upper gastrointestinal tract, with a major focus on addressing the protection of the esophagus and stomach by this emerging compound.

Cellular and molecular mechanisms of curcumin in prevention and treatment of disease

Curcumin is a naturally occurring polyphenolic compound present in rhizome of Curcuma longa belonging to the family zingiberaceae. Growing experimental evidence revealed that curcumin exhibit multitarget biological implications signifying its crucial role in health and disease. The current review highlights the recent progress and mechanisms underlying the wide range of pharmacological effects of curcumin against numerous diseases like neuronal, cardiovascular, metabolic, kidney, endocrine, skin, respiratory, infectious, gastrointestinal diseases and cancer. The ability of curcumin to modulate the functions of multiple signal transductions are linked with attenuation of acute and chronic diseases. Numerous preclinical and clinical studies have revealed that curcumin modulates several molecules in cell signal transduction pathway including PI3K, Akt, mTOR, ERK5, AP-1, TGF-β, Wnt, β-catenin, Shh, PAK1, Rac1, STAT3, PPARγ, EBPα, NLRP3 inflammasome, p38MAPK, Nrf2, Notch-1, AMPK, TLR-4 and MyD-88. Curcumin has a potential to prevent and/or manage various diseases due to its anti-inflammatory, anti-oxidant and anti-apoptotic properties with an excellent safety profile. In contrast, the anti-cancer effects of curcumin are reflected due to induction of growth arrest and apoptosis in various premalignant and malignant cells. This review also carefully emphasized the pharmacokinetics of curcumin and its interaction with other drugs. Clinical studies have shown that curcumin is safe at the doses of 12 g/day but exhibits poor systemic bioavailability. The use of adjuvant like piperine, liposomal curcumin, curcumin nanoparticles and curcumin phospholipid complex has shown enhanced bioavailability and therapeutic potential. Further studies are warranted to prove the potential of curcumin against various ailments.

Highly photoluminescent and temperature-sensitive P, N, B-co-doped carbon quantum dots and their highly sensitive recognition for curcumin

Temperature-sensitive P, N, B-co-doped carbon quantum dots (PNBCDs) synthesized using one-pot method exhibit many excellent features, such as strong fluorescence, good stability and sensitive detection for curcumin.

Mechanistic insights of hepatoprotective effects of curcumin: Therapeutic updates and future prospects

The liver is the most essential organ of the body performing vital functions. Hepatic disorders affect the physiological and biochemical functions of the body. These disorders include hepatitis B, hepatitis C, alcoholic liver disease (ALD), nonalcoholic fatty liver disease (NAFLD), liver cirrhosis, hepatic failure and hepatocellular carcinoma (HCC). Drugs related hepatotoxicity is one of the major challenges facing by clinicians as it is a leading cause of liver failure. During post-marketing surveillance studies, detection and reporting of drug-induced hepatotoxicity may lead to drug withdrawal or warnings. Several mechanisms are involved in hepatotoxicity such as cell membrane disruption, initiating an immune response, alteration of cellular pathways of drug metabolism, accumulation of reactive oxygen species (ROS), lipid peroxidation and cell death. Curcumin, the active ingredient of turmeric and exhibits therapeutic potential for the treatment of diabetes, cardiovascular disorders and various types of cancers. Curcumin is strong anti-oxidant and anti-inflammatory effects and thus it possesses hepatoprotective properties. Despite its low bioavailability, its hepatoprotective effects have been studied in various protocols of hepatotoxicity including acetaminophen, alcohol, lindane, carbon tetrachloride (CCL₄), diethylnitrosamine and heavy metals induced hepatotoxicities. This report reviews the hepatoprotective effects of curcumin with a focus on its mechanistic insights in various hepatotoxic protocols.

The effect of antioxidants on Helicobacter pylori eradication: A systematic review with meta-analysis

BACKGROUND

The efficacy and safety of the addition of antioxidants to triple or quadruple therapy were unclear.

MATERIALS AND METHODS

This systematic review was performed in accordance with the PRISMA 2009 guidelines. A systematic search of PubMed, EMBASE, and the Cochrane Library databases was conducted to identify potentially relevant publications using the following keywords: ([Helicobacter pylori] or [H. pylori] or [Hp]) and ([antioxidant] or [vitamin] or [N-acetylcysteine] or [curcumin] or [cranberry]). The primary end-point of this study was to evaluate the efficacy of the addition of antioxidants to triple or quadruple therapy according to ITT and PP analysis. The second end-points were side effects and the comparative efficacy in terms of H. pylori eradication according to different antioxidant and antibiotic combinations.

RESULTS

We included 9 studies with 1260 participants. The total eradication rate of H. pylori in the group combining eradication therapy with antioxidants was not superior to that without antioxidants according to the ITT (pooled RR [95% CI] = 1.17 [0.99-1.38]; P = 0.07) and PP analysis (pooled RR [95% CI] = 1.15 [0.99-1.34; P = 0.07]. There were no differences regarding side effects between the two groups (pooled RR [95% CI], 1.36 [0.81-2.28]; P = 0.24). However, the eradication regimen with vitamin supplementation (1400 mg/day) showed a significant, superior efficacy in eradication relative to those without supplementation (pooled RR [95% CI] = 1.57 [1.35, 1.84]; P < 0.01). In particular, in the amoxicillin-clarithromycin-based subgroup, the crude H. pylori eradication rate determined by ITT analysis was 81.3% and 68.6% for eradication therapy with and without antioxidant supplementation, respectively, which was a statistically significant difference (pooled RR [95% CI] = 1.23 [1.02-1.49]; P = 0.03).

CONCLUSIONS

The addition of antioxidants (vitamin, N-acetylcysteine, curcumin, cranberry) to amoxicillin-clarithromycin-based therapy could improve the eradication rate, and vitamin supplementation might be effective at a high dosage. However, antioxidant supplements have no impact on improving side effects.

Downregulation of Interleukin- (IL-) 17 through Enhanced Indoleamine 2,3-Dioxygenase (IDO) Induction by Curcumin: A Potential Mechanism of Tolerance towards Helicobacter pylori

The anti-inflammatory and antimicrobial properties of curcumin suggest its use as an anti-Helicobacter pylori (H. pylori) agent, but mechanisms underlying its helpful activity are still not clear. Indoleamine 2,3-dioxygenase (IDO) promotes the effector T cell apoptosis by catalyzing the rate-limiting first step in tryptophan catabolism, and its high expression in H. pylori-infected human gastric mucosa attenuates Th1 and Th17 immune response. The aim of this study was to investigate the role of curcumin in modulating the expression of IL-17 and IDO in H. pylori-infected human gastric mucosa. In an organ culture chamber, gastric biopsies from 35 patients were treated with and without 200 μM curcumin. In H. pylori-infected patients (n = 21), IL-17 was significantly lower, both in gastric biopsies (p = 0.0003) and culture supernatant (p = 0.0001) while IDO significantly increased (p < 0.00001) in curcumin-treated sample compared with untreated samples. In a subgroup of H. pylori-infected patients (n = 15), samples treated with curcumin in addition to IDO inhibitor 1-methyl-L-tryptophan (1-MT) showed a higher expression of IL-17 compared with untreated samples and curcumin-treated alone (p < 0.00001). Curcumin downregulates IL-17 production through the induction of IDO in H. pylori-infected human gastric mucosa, suggesting its role in dampening H. pylori-induced immune-mediated inflammatory changes.

The Problem of Curcumin and Its Bioavailability: Could Its Gastrointestinal Influence Contribute to Its Overall Health-Enhancing Effects?

Curcumin, from the spice turmeric, exhibits anti-inflammatory, antioxidant, anticancer, antiviral, and neurotrophic activity and therefore holds promise as a therapeutic agent to prevent and treat several disorders. However, a major barrier to curcumin's clinical efficacy is its poor bioavailability. Efforts have therefore been dedicated to developing curcumin formulations with greater bioavailability and systemic tissue distribution. However, it is proposed in this review that curcumin's potential as a therapeutic agent may not solely rely on its bioavailability, but rather its medicinal benefits may also arise from its positive influence on gastrointestinal health and function. In this review, in vitro, animal, and human studies investigating the effects of curcumin on intestinal microbiota, intestinal permeability, gut inflammation and oxidative stress, anaphylactic response, and bacterial, parasitic, and fungal infections are summarized. It is argued that positive changes in these areas can have wide-ranging influences on both intestinal and extraintestinal diseases, and therefore presents as a possible mechanism behind curcumin's therapeutic efficacy.

Effect of Curcumin on the Diversity of Gut Microbiota in Ovariectomized Rats

Curcumin has been proven to have a weight-loss effect in a menopausal rat model induced by ovariectomy. However, the effects of curcumin on gut microfloral communities of ovariectomized (OVX) rats remains unclear. Here, we used high-throughput 16S rDNA sequencing to explore the effects of curcumin on microbial diversity in the gut of OVX rats. Female Wistar rats were subjected to either ovariectomy or a sham operation (SHAM group). The OVX rats were treated with vehicle (OVX group) or curcumin (CUR group) by oral gavage. After 12-week treatments, the weights of the bodies and uteri of rats were recorded, the levels of estradiol in the serum were assayed by electrochemiluminescence immunoassay (ECLIA). Then, the fragments encompassing V3–V4 16S rDNA hypervariable regions were PCR amplified from fecal samples, and the PCR products of V3–V4 were sequenced on an Illumina MiSeq for characterization of the gut microbiota. Our results showed that, compared to rats in the SHAM group, rats in the OVX group had more weight gain and lower levels of estradiol in the serum, and curcumin could cause significant weight loss in OVX rats but did not increase the levels of estradiol. Sequencing results revealed the presence of 1120, 1114, and 1119 operational taxonomic units (OTUs) found in the SHAM, OVX, and CUR groups, respectively. The percentage of shared OTUs was 86.1603%. Gut microbiota of rats from the SHAM or CUR group had higher levels of biodiversity and unevenness estimations than those from the OVX group. At the phyla level, compared to rats in SHAM group, rats in the OVX group had a higher ratio of phyla Firmicutes and Bacteroidetes in the gut; at the genus level, four differential gut microbiota (Incertae_Sedis, Anaerovorax, Anaerotruncus, and Helicobacter) between SHAM and OVX groups were found, whereas seven differential gut microbiota (Serratia, Anaerotruncus, Shewanella, Pseudomonas, Papillibacter, Exiguobacterium, and Helicobacter) between OVX and CUR groups were found. In conclusion, estrogen deficiency induced by ovariectomy caused changes in the distribution and structure of intestinal microflora in rats, and curcumin could partially reverse changes in the diversity of gut microbiota.

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.

Multifunctional Curcumin Mediate Multitherapeutic Effects

Inflammation can promote the development of arthritis, obesity, cardiovascular, type II diabetes, pancreatitis, metabolic and neurodegenerative diseases, and certain types of cancer. Compounds isolated from plants have been practiced since ancient times for curing various ailments including inflammatory disorders and to support normal physiological functions. Curcumin (diferuloylmethane) is a yellow coloring agent, extracted from turmeric that has been used for the prevention and treatment of various inflammatory diseases. Numerous studies have shown that curcumin modulate multiple molecular targets and can be translated to the clinics for multiple therapeutic processes. There is compelling evidence that curcumin can block cell proliferation, invasion, and angiogenesis as well as reduced the prolonged survival of cancer cells. Curcumin mediates anti-inflammatory effect through downregulation of inflammatory cytokines, transcription factors, protein kinases, and enzymes that promote inflammation and development of chronic diseases. In addition, curcumin induces apoptosis through mitochondrial and receptor-mediated pathways by activating caspase cascades. Curcumin is a safe and nontoxic drug that has been reported to be well tolerated. Available clinical trials support the potential role of curcumin for treatment of various inflammatory disorders. However, curcumin's efficacy is hindered by poor absorption and low bioavailability, which limit its translation into clinics. This review outlines the potential pharmacological and clinical role of curcumin, which provide a gateway for the beneficial role of plant isolated compounds in treatment of various inflammatory diseases and cancer.

Regulation of PCSK9 by nutraceuticals

PCSK9 (proprotein convertase subtilisin kexin type 9) is a liver secretory enzyme that regulates plasma low-density lipoprotein (LDL) cholesterol (LDL-C) levels through modulation of LDL receptor (LDLR) density on the surface of hepatocytes. Inhibition of PCSK9 using monoclonal antibodies can efficiently lower plasma LDL-C, non-high-density lipoprotein cholesterol and lipoprotein (a). PCSK9 inhibition is also an effective adjunct to statin therapy; however, the cost-effectiveness of currently available PCSK9 inhibitors is under question. Nutraceuticals offer a safe and cost-effective option for PCSK9 inhibition. Several nutraceuticals have been reported to modulate PCSK9 levels and exert LDL-lowering activity. Mechanistically, those nutraceuticals that inhibit PCSK9 through a SREBP (sterol-responsive element binding protein)-independent pathway can be more effective in lowering plasma LDL-C levels compared with those inhibiting PCSK9 through the SREBP pathway. The present review aims to collect available data on the nutraceuticals with PCSK9-inhibitory effect and the underlying mechanisms.