Rheumatoid arthritis molecular targets and their importance to flavonoid-based therapy

Rheumatoid arthritis (RA) is a progressive, chronic, autoimmune, inflammatory, and systemic condition that primarily affects the synovial joints and adjacent tissues, including bone, muscle, and tendons. The World Health Organization recognizes RA as one of the most prevalent chronic inflammatory diseases. In the last decade, there was an expansion on the available RA therapeutic options which aimed to improve patient's quality of life. Despite the extensive research and the emergence of new therapeutic approaches and drugs, there are still significant unwanted side effects associated to these drugs and still a vast number of patients that do not respond positively to the existing therapeutic strategies. Over the years, several references to the use of flavonoids in the quest for new treatments for RA have emerged. This review aimed to summarize the existing literature about the flavonoids' effects on the major pathogenic/molecular targets of RA and their potential use as lead compounds for the development of new effective molecules for RA treatment. It is demonstrated that flavonoids can modulate various players in synovial inflammation, regulate immune cell function, decrease synoviocytes proliferation and balance the apoptotic process, decrease angiogenesis, and stop/prevent bone and cartilage degradation, which are all dominant features of RA. Although further investigation is necessary to determine the effectiveness of flavonoids in humans, the available data from in vitro and in vivo models suggest their potential as new disease-modifying anti-rheumatic drugs. This review highlights the use of flavonoids as a promising avenue for future research in the treatment of RA.

Melanoxetin: A Hydroxylated Flavonoid Attenuates Oxidative Stress and Modulates Insulin Resistance and Glycation Pathways in an Animal Model of Type 2 Diabetes Mellitus

Type 2 diabetes mellitus (DM) continues to escalate, necessitating innovative therapeutic approaches that target distinct pathways and address DM complications. Flavonoids have been shown to possess several pharmacological activities that are important for DM. This study aimed to evaluate the in vivo effects of the flavonoid melanoxetin using Goto-Kakizaki rats. Over a period of 14 days, melanoxetin was administered subcutaneously to investigate its antioxidant, anti-inflammatory, and antidiabetic properties. The results show that melanoxetin reduced insulin resistance in adipose tissue by targeting protein tyrosine phosphatase 1B. Additionally, melanoxetin counteracted oxidative stress by reducing nitrotyrosine levels and modulating superoxide dismutase 1 and hemeoxygenase in adipose tissue and decreasing methylglyoxal-derived hydroimidazolone (MG-H1), a key advanced glycation end product (AGE) implicated in DM-related complications. Moreover, the glyoxalase 1 expression decreased in both the liver and the heart, correlating with reduced AGE levels, particularly MG-H1 in the heart. Melanoxetin also demonstrated anti-inflammatory effects by reducing serum prostaglandin E2 levels, and increasing the antioxidant status of the aorta wall through enhanced acetylcholine-dependent relaxation in the presence of ascorbic acid. These findings provide valuable insights into melanoxetin's therapeutic potential in targeting multiple pathways involved in type 2 DM, particularly in mitigating oxidative stress and glycation.

The role of flavonoids in the regulation of epithelial-mesenchymal transition in cancer: A review on targeting signaling pathways and metastasis

One of the hallmarks of cancer is metastasis, a process that entails the spread of cancer cells to distant regions in the body, culminating in tumor formation in secondary organs. Importantly, the proinflammatory environment surrounding cancer cells further contributes to cancer cell transformation and extracellular matrix destruction. During metastasis, front-rear polarity and emergence of migratory and invasive features are manifestations of epithelial-mesenchymal transition (EMT). A variety of transcription factors (TFs) are implicated in the execution of EMT, the most prominent belonging to the Snail Family Transcriptional Repressor (SNAI) and Zinc Finger E-Box Binding Homeobox (ZEB) families of TFs. These TFs are regulated by interaction with specific microRNAs (miRNAs), as miR34 and miR200. Among the several secondary metabolites produced in plants, flavonoids constitute a major group of bioactive molecules, with several described effects including antioxidant, antiinflammatory, antidiabetic, antiobesogenic, and anticancer effects. This review scrutinizes the modulatory role of flavonoids on the activity of SNAI/ZEB TFs and on their regulatory miRNAs, miR-34, and miR-200. The modulatory role of flavonoids can attenuate mesenchymal features and stimulate epithelial features, thereby inhibiting and reversing EMT. Moreover, this modulation is concomitant with the attenuation of signaling pathways involved in diverse processes as cell proliferation, cell growth, cell cycle progression, apoptosis inhibition, morphogenesis, cell fate, cell migration, cell polarity, and wound healing. The antimetastatic potential of these versatile compounds is emerging and represents an opportunity for the synthesis of more specific and potent agents.

Biodistribution and intestinal inflammatory response following voluntary oral intake of silver nanoparticles by C57BL/6J mice

Silver nanoparticles (AgNP) are among the most widely commercialized nanomaterials globally, with applications in medicine and the food industry. Consequently, the increased use of AgNP in the food industry has led to an unavoidable rise  in human exposure to these nanoparticles. Their widespread use raises concerns about potential hazards to human health, specifically their intestinal pro-inflammatory effects. Thus, the main objective of this study was to evaluate the biological effects of two subacute doses of 5 nm polyvinylpyrrolidone (PVP)-AgNP in C57BL/6J mice. One mg/kg body weight or 10 mg/kg bw was provided once a day for 14 days, using a new technology (HaPILLness) that allows voluntary, stress-free, and accurate oral dosing. It was observed that after oral ingestion, while AgNP is biodistributed throughout the entire organism, most of the ingested dose is excreted in the feces. The passage and accumulation of AgNP throughout the intestine instigated a prominent inflammatory response, marked by significant histological, vascular, and cellular transformations. This response was driven by the activation of the nuclear factor-кB (NF-кB) inflammatory pathway, ultimately leading to the generation of multiple cytokines and chemokines.

Global, regional, and national burden of osteoarthritis, 1990-2020 and projections to 2050: a systematic analysis for the Global Burden of Disease Study 2021

Background

Osteoarthritis is the most common form of arthritis in adults, characterised by chronic pain and loss of mobility. Osteoarthritis most frequently occurs after age 40 years and prevalence increases steeply with age. WHO has designated 2021-30 the decade of healthy ageing, which highlights the need to address diseases such as osteoarthritis, which strongly affect functional ability and quality of life. Osteoarthritis can coexist with, and negatively effect, other chronic conditions. Here we estimate the burden of hand, hip, knee, and other sites of osteoarthritis across geographies, age, sex, and time, with forecasts of prevalence to 2050.

Methods

In this systematic analysis for the Global Burden of Disease Study, osteoarthritis prevalence in 204 countries and territories from 1990 to 2020 was estimated using data from population-based surveys from 26 countries for knee osteoarthritis, 23 countries for hip osteoarthritis, 42 countries for hand osteoarthritis, and US insurance claims for all of the osteoarthritis sites, including the other types of osteoarthritis category. The reference case definition was symptomatic, radiographically confirmed osteoarthritis. Studies using alternative definitions from the reference case definition (for example self-reported osteoarthritis) were adjusted to reference using regression models. Osteoarthritis severity distribution was obtained from a pooled meta-analysis of sources using the Western Ontario and McMaster Universities Arthritis Index. Final prevalence estimates were multiplied by disability weights to calculate years lived with disability (YLDs). Prevalence was forecast to 2050 using a mixed-effects model.

Findings

Globally, 595 million (95% uncertainty interval 535-656) people had osteoarthritis in 2020, equal to 7·6% (95% UI 6·8-8·4) of the global population, and an increase of 132·2% (130·3-134·1) in total cases since 1990. Compared with 2020, cases of osteoarthritis are projected to increase 74·9% (59·4-89·9) for knee, 48·6% (35·9-67·1) for hand, 78·6% (57·7-105·3) for hip, and 95·1% (68·1-135·0) for other types of osteoarthritis by 2050. The global age-standardised rate of YLDs for total osteoarthritis was 255·0 YLDs (119·7-557·2) per 100 000 in 2020, a 9·5% (8·6-10·1) increase from 1990 (233·0 YLDs per 100 000, 109·3-510·8). For adults aged 70 years and older, osteoarthritis was the seventh ranked cause of YLDs. Age-standardised prevalence in 2020 was more than 5·5% in all world regions, ranging from 5677·4 (5029·8-6318·1) per 100 000 in southeast Asia to 8632·7 (7852·0-9469·1) per 100 000 in high-income Asia Pacific. Knee was the most common site for osteoarthritis. High BMI contributed to 20·4% (95% UI -1·7 to 36·6) of osteoarthritis. Potentially modifiable risk factors for osteoarthritis such as recreational injury prevention and occupational hazards have not yet been explored in GBD modelling.

Interpretation

Age-standardised YLDs attributable to osteoarthritis are continuing to rise and will lead to substantial increases in case numbers because of population growth and ageing, and because there is no effective cure for osteoarthritis. The demand on health systems for care of patients with osteoarthritis, including joint replacements, which are highly effective for late stage osteoarthritis in hips and knees, will rise in all regions, but might be out of reach and lead to further health inequity for individuals and countries unable to afford them. Much more can and should be done to prevent people getting to that late stage.

Funding

Bill & Melinda Gates Foundation, Institute of Bone and Joint Research, and Global Alliance for Musculoskeletal Health.

Methodologies for Assessing Pancreatic Lipase Catalytic Activity: A Review

Obesity is a disease of epidemic proportions with a concerning increasing trend. Regarded as one of the main sources of energy, lipids can also represent a big part of an unnecessary intake of calories and be, therefore, directly related to the problem of obesity. Pancreatic lipase is an enzyme that is essential in the absorption and digestion of dietary fats and has been explored as an alternative for the reduction of fat absorption and consequent weigh loss.Literature describes a great variability of methodologies and experimental conditions used in research to evaluate the in vitro inhibitory activity of compounds against pancreatic lipase. However, in an attempt to choose the best approach, it is necessary to know all the reaction conditions and understand how these can affect the enzymatic assay.The objective of this review is to understand and summarize the methodologies and respective experimental conditions that are mainly used to evaluate pancreatic lipase catalytic activity.156 studies were included in this work and a detailed description of the most commonly used UV/Vis spectrophotometric and fluorimetric instrumental techniques are presented, including a discussion regarding the differences found in the parameters used in both techniques, namely enzyme, substrate, buffer solutions, kinetics conditions, temperature and pH.This works shows that both UV/Vis spectrophotometry and fluorimetry are useful instrumental techniques for the evaluation of pancreatic lipase catalytic activity, presenting several advantages and limitations, which make the choice of parameters and experimental conditions a crucial decision to obtain the most reliable results.

Silver nanoparticles exert toxic effects in human monocytes and macrophages associated with the disruption of Δψm and release of pro-inflammatory cytokines

Silver nanoparticles (AgNP) are the most widely produced type of nanoparticles due to their antimicrobial and preservative properties. However, their systemic bioavailability may be considered a potential hazard. When AgNP reach the bloodstream, they interact with the immune cells, contributing to the onset and development of an inflammatory response. Monocytes and macrophages play a pivotal role in our defense system, but the interaction of AgNP with these cells is still not clear. Therefore, the main objective of this work was to assess the cytotoxic and pro-inflammatory effects induced by 5, 10, and 50 nm AgNP coated with polyvinylpyrrolidone (PVP) and citrate, in concentrations that could be attained in vivo (0-25 μg/mL), in human monocytes isolated from human blood and human macrophages derived from a monocytic cell line (THP-1). The effects of PVP and citrate-coated AgNP on cell viability, mitochondrial membrane potential, and cytokines release were evaluated. The results evidenced that AgNP exert strong harmful effects in both monocytes and macrophages, through the establishment of a strong pro-inflammatory response that culminates in cell death. The observed effects were dependent on the AgNP concentration, size and coating, being observed more pronounced cytotoxic effects with smaller PVP coated AgNP. The results showed that human monocytes seem to be more sensitive to AgNP exposure than human macrophages. Considering the increased daily use of AgNP, it is imperative to further explore the adverse outcomes and mechanistic pathways leading to AgNP-induced pro-inflammatory effects to deep insight into the molecular mechanism involved in this effect.

Estimates, trends, and drivers of the global burden of type 2 diabetes attributable to PM2·5 air pollution, 1990-2019: an analysis of data from the Global Burden of Disease Study 2019

BACKGROUND

Experimental and epidemiological studies indicate an association between exposure to particulate matter (PM) air pollution and increased risk of type 2 diabetes. In view of the high and increasing prevalence of diabetes, we aimed to quantify the burden of type 2 diabetes attributable to PM2·5 originating from ambient and household air pollution.

METHODS

We systematically compiled all relevant cohort and case-control studies assessing the effect of exposure to household and ambient fine particulate matter (PM2·5) air pollution on type 2 diabetes incidence and mortality. We derived an exposure-response curve from the extracted relative risk estimates using the MR-BRT (meta-regression-Bayesian, regularised, trimmed) tool. The estimated curve was linked to ambient and household PM2·5 exposures from the Global Burden of Diseases, Injuries, and Risk Factors Study 2019, and estimates of the attributable burden (population attributable fractions and rates per 100 000 population of deaths and disability-adjusted life-years) for 204 countries from 1990 to 2019 were calculated. We also assessed the role of changes in exposure, population size, age, and type 2 diabetes incidence in the observed trend in PM2·5-attributable type 2 diabetes burden. All estimates are presented with 95% uncertainty intervals.

FINDINGS

In 2019, approximately a fifth of the global burden of type 2 diabetes was attributable to PM2·5 exposure, with an estimated 3·78 (95% uncertainty interval 2·68-4·83) deaths per 100 000 population and 167 (117-223) disability-adjusted life-years (DALYs) per 100 000 population. Approximately 13·4% (9·49-17·5) of deaths and 13·6% (9·73-17·9) of DALYs due to type 2 diabetes were contributed by ambient PM2·5, and 6·50% (4·22-9·53) of deaths and 5·92% (3·81-8·64) of DALYs by household air pollution. High burdens, in terms of numbers as well as rates, were estimated in Asia, sub-Saharan Africa, and South America. Since 1990, the attributable burden has increased by 50%, driven largely by population growth and ageing. Globally, the impact of reductions in household air pollution was largely offset by increased ambient PM2·5.

INTERPRETATION

Air pollution is a major risk factor for diabetes. We estimated that about a fifth of the global burden of type 2 diabetes is attributable PM2·5 pollution. Air pollution mitigation therefore might have an essential role in reducing the global disease burden resulting from type 2 diabetes.

FUNDING

Bill & Melinda Gates Foundation.

Ultrasonographic scores for ileal Crohn's disease assessment: Better, worse or the same as contrast-enhanced ultrasound?

BACKGROUND

Intestinal ultrasound (IUS) is an increasingly used non-invasive tool to evaluate Crohn's disease (CD) activity. Recently, two IUS scores that evaluate inflammatory activity have emerged: the Simple Ultrasound Activity Score for CD (SUS-CD) and the International Bowel Ultrasound Segmental Activity Score (IBUS-SAS). We aimed to compare the accuracy of SUS-CD, IBUS-SAS and contrast-enhanced ultrasound (CEUS) in predicting inflammatory activity in the terminal ileum in ileocolonoscopy in CD patients.

METHODS

Retrospective study including all consecutive CD patients submitted to IUS with CEUS directed to the terminal ileum performed by a single operator between April 2016 and March 2020. Segmental SUS-CD and IBUS-SAS were calculated. A time-intensity curve of the contrast bowel wall enhancement was created with measurement of peak intensity using CEUS. The CD endoscopic activity in ileocolonoscopy was graded by Simple Endoscopic Score for CD (SES-CD) as inactive (SES-CD < 7) or active (SES-CD ≥ 7).

RESULTS

Fifty patients were included, 54.0% were female, with mean age of 34 ± 12 years, and most had isolated ileal disease (60.0%), and a nonstricturing, nonpenetrating behaviour (44.0%). Most of the patients (60.0%) had active endoscopic disease (SES-CD ≥ 7). SUS-CD and IBUS-SAS were not different between patients with active or inactive endoscopic disease (p = 0.15; 0.57, respectively), having a poor accuracy to correlate endoscopic activity (area under de curve (AUC) 0.62; 0.55, respectively). Peak intensity in CEUS was significantly different in patients with active or inactive endoscopic disease (p = 0.004), having a good accuracy to correlate endoscopic activity (AUC 0.80).

CONCLUSION

Unlike CEUS, SUS-CD and IBUS-SAS were not able to accurately correlate endoscopic activity in terminal ileum in CD. Therefore, CEUS is a non-invasive emerging method that should be increasingly integrated in the ultrasonographic evaluation of CD patients.

Pro-inflammatory effects of silver nanoparticles in the intestine

Nanotechnology is a promising technology of the twenty-first century, being a rapidly evolving field of research and industrial innovation widely applied in our everyday life. Silver nanoparticles (AgNP) are considered the most commercialized nanosystems worldwide, being applied in diverse sectors, from medicine to the food industry. Considering their unique physical, chemical and biological properties, AgNP have gained access into our daily life, with an exponential use in food industry, leading to an increased inevitable human oral exposure. With the growing use of AgNP, several concerns have been raised, in recent years, about their potential hazards to human health, more precisely their pro-inflammatory effects within the gastrointestinal system. Therefore a review of the literature has been undertaken to understand the pro-inflammatory potential of AgNP, after human oral exposure, in the intestine. Despite the paucity of information reported in the literature about this issue, existing studies indicate that AgNP exert a pro-inflammatory action, through generation of oxidative stress, accompanied by mitochondrial dysfunction, interference with transcription factors and production of cytokines. However, further studies are needed to elucidate the mechanistic pathways and molecular targets involved in the intestinal pro-inflammatory effects of AgNP.

Diabetes mortality and trends before 25 years of age: an analysis of the Global Burden of Disease Study 2019

BACKGROUND

Diabetes, particularly type 1 diabetes, at younger ages can be a largely preventable cause of death with the correct health care and services. We aimed to evaluate diabetes mortality and trends at ages younger than 25 years globally using data from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019.

METHODS

We used estimates of GBD 2019 to calculate international diabetes mortality at ages younger than 25 years in 1990 and 2019. Data sources for causes of death were obtained from vital registration systems, verbal autopsies, and other surveillance systems for 1990-2019. We estimated death rates for each location using the GBD Cause of Death Ensemble model. We analysed the association of age-standardised death rates per 100 000 population with the Socio-demographic Index (SDI) and a measure of universal health coverage (UHC) and described the variability within SDI quintiles. We present estimates with their 95% uncertainty intervals.

FINDINGS

In 2019, 16 300 (95% uncertainty interval 14 200 to 18 900) global deaths due to diabetes (type 1 and 2 combined) occurred in people younger than 25 years and 73·7% (68·3 to 77·4) were classified as due to type 1 diabetes. The age-standardised death rate was 0·50 (0·44 to 0·58) per 100 000 population, and 15 900 (97·5%) of these deaths occurred in low to high-middle SDI countries. The rate was 0·13 (0·12 to 0·14) per 100 000 population in the high SDI quintile, 0·60 (0·51 to 0·70) per 100 000 population in the low-middle SDI quintile, and 0·71 (0·60 to 0·86) per 100 000 population in the low SDI quintile. Within SDI quintiles, we observed large variability in rates across countries, in part explained by the extent of UHC (r2=0·62). From 1990 to 2019, age-standardised death rates decreased globally by 17·0% (-28·4 to -2·9) for all diabetes, and by 21·0% (-33·0 to -5·9) when considering only type 1 diabetes. However, the low SDI quintile had the lowest decline for both all diabetes (-13·6% [-28·4 to 3·4]) and for type 1 diabetes (-13·6% [-29·3 to 8·9]).

INTERPRETATION

Decreasing diabetes mortality at ages younger than 25 years remains an important challenge, especially in low and low-middle SDI countries. Inadequate diagnosis and treatment of diabetes is likely to be major contributor to these early deaths, highlighting the urgent need to provide better access to insulin and basic diabetes education and care. This mortality metric, derived from readily available and frequently updated GBD data, can help to monitor preventable diabetes-related deaths over time globally, aligned with the UN's Sustainable Development Targets, and serve as an indicator of the adequacy of basic diabetes care for type 1 and type 2 diabetes across nations.

FUNDING

Bill & Melinda Gates Foundation.

2-Styrylchromones: Cytotoxicity and Modulation of Human Neutrophils' Oxidative Burst

Neutrophils are polymorphonuclear leukocytes recruited to sites of acute inflammation, in response to pathogen invasion and tissue injury. The modulation of their activity, especially oxidative burst, may be important to control the inflammatory process. 2-Styrylchromones (2-SC) are derived from chromones and despite their recognized multiple biological activities, their anti-inflammatory and antioxidant properties are still poorly explored. Therefore, in this study, 43 structurally related 2-SC were evaluated concerning their effects on freshly isolated human neutrophils’ viability and oxidative burst. The studied 2-SC were divided into eight groups according to their substitution at C-4′ on B-ring (none, -OH, -OCH3, -OBn, -CH3, and -NO2), existence and location of -Cl on B-ring, and presence of -Br at C-3 on C-ring. Overall, most of the studied 2-SC did not affect neutrophils’ viability, at physiological relevant concentrations. The ones belonging to B group were the most effective (IC50 values < 2 μM), and present one -OH group at C-4′ or a catechol group at C-3′ and C-4′ on B-ring. These substituents seem to play an important role in the modulatory activity of human neutrophils’ oxidative burst. These results reinforce the great potential of 2-SC’s scaffold for the development of new anti-inflammatory agents.

Inhibitory activity of flavonoids against human sucrase-isomaltase (α-glucosidase) activity in a Caco-2/TC7 cellular model

Type 2 diabetes (T2D) is the most common form of diabetes, and the number of people with this metabolic disease is steadily increasing worldwide. Among the available antidiabetic agents, α-glucosidase inhibitors are the most effective at reducing postprandial hyperglycaemia (PPHG), one of the main characteristics of T2D. However, most of the studies that have been performed have used the more readily available rat intestinal preparations or yeast α-glucosidase as the enzyme source, which despite being useful and cost effective, have a questionable physiological value. The present study evaluates the inhibitory activity of a selected group of flavonoids against human sucrase-isomaltase (SI), the α-glucosidase found in Caco-2/TC7 cells. A microassay using the physiological substrates sucrose and maltose, and a synthetic substrate, p-nitrophenyl-α-D-glucopyranoside (pNPG) was performed. The most active flavonoid was compound 4 (melanoxetin), presenting an IC₅₀ value similar using the two natural substrates. In contrast, the tested flavonoids were not effective at inhibiting SI, when pNPG was used as a substrate. Hydroxylation of flavonoids at C-3 of the C ring, at C-3' and C-4' of the B ring, and at C-7 and C-8 of the A ring were the features that improved the inhibitory activity of flavonoids against human SI. These phenolic compounds deserve further exploration as alternatives to the currently available α-glucosidase inhibitors. The present study also demonstrates that the non-clinical in vitro studies conducted for the evaluation of α-glucosidase activity should use the human source rather than surrogate sources of α-glucosidase.

An In Silico and an In Vitro Inhibition Analysis of Glycogen Phosphorylase by Flavonoids, Styrylchromones, and Pyrazoles

Glycogen phosphorylase (GP) is a key enzyme in the glycogenolysis pathway. GP inhibitors are currently under investigation as a new liver-targeted approach to managing type 2 diabetes mellitus (DM). The aim of the present study was to evaluate the inhibitory activity of a panel of 52 structurally related chromone derivatives; namely, flavonoids, 2-styrylchromones, 2-styrylchromone-related derivatives [2-(4-arylbuta-1,3-dien-1-yl)chromones], and 4- and 5-styrylpyrazoles against GP, using in silico and in vitro microanalysis screening systems. Several of the tested compounds showed a potent inhibitory effect. The structure–activity relationship study indicated that for 2-styrylchromones and 2-styrylchromone-related derivatives, the hydroxylations at the A and B rings, and in the flavonoid family, as well as the hydroxylation of the A ring, were determinants for the inhibitory activity. To support the in vitro experimental findings, molecular docking studies were performed, revealing clear hydrogen bonding patterns that favored the inhibitory effects of flavonoids, 2-styrylchromones, and 2-styrylchromone-related derivatives. Interestingly, the potency of the most active compounds increased almost four-fold when the concentration of glucose increased, presenting an IC₅₀ < 10 µM. This effect may reduce the risk of hypoglycemia, a commonly reported side effect of antidiabetic agents. This work contributes with important considerations and provides a better understanding of potential scaffolds for the study of novel GP inhibitors.

Inhibition of the carbohydrate-hydrolyzing enzymes α-amylase and α-glucosidase by hydroxylated xanthones

Xanthones are oxygen-containing heterocyclic compounds that exhibit a wide range of biological and pharmacological properties. Some natural and synthetic derivatives have been identified for their antidiabetic profile, mainly as α-glucosidase...

Styrylchromones: Biological Activities and Structure-Activity Relationship

Styrylchromones (SC) are a group of oxygen-containing heterocyclic compounds, which are characterized by the attachment of a styryl group to the chromone core. SC can be found in nature or can be chemically synthesized in the laboratory. As their presence in nature is scarce, the synthetic origin is the most common. Two types of SC are known: 2-styrylchromones and 3-styrylchromones. However, 2-styrylchromones are the most common, being more commonly found in nature and which chemical synthesis is more commonly described. A wide variety of SC has been described in the literature, with different substituents in different positions, the majority of which are distributed on the A- and/or B-rings. Over the years, several biological activities have been attributed to SC. This work presents a comprehensive review of the biological activities attributed to SC and their structure-activity relationship, based on a published literature search, since 1989. The following biological activities are thoroughly revised and discussed in this review: antioxidant, antiallergic, antiviral, antibacterial, antifungal, anti-inflammatory, and antitumoral, affinity and selectivity for A3 adenosine receptors, neuroprotective, and α-glucosidase inhibition. In general, SC are composed by a promising scaffold with great potential for the development of new drugs.

Global, regional, and national progress towards Sustainable Development Goal 3.2 for neonatal and child health: all-cause and cause-specific mortality findings from the Global Burden of Disease Study 2019

BACKGROUND

Sustainable Development Goal 3.2 has targeted elimination of preventable child mortality, reduction of neonatal death to less than 12 per 1000 livebirths, and reduction of death of children younger than 5 years to less than 25 per 1000 livebirths, for each country by 2030. To understand current rates, recent trends, and potential trajectories of child mortality for the next decade, we present the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019 findings for all-cause mortality and cause-specific mortality in children younger than 5 years of age, with multiple scenarios for child mortality in 2030 that include the consideration of potential effects of COVID-19, and a novel framework for quantifying optimal child survival.

METHODS

We completed all-cause mortality and cause-specific mortality analyses from 204 countries and territories for detailed age groups separately, with aggregated mortality probabilities per 1000 livebirths computed for neonatal mortality rate (NMR) and under-5 mortality rate (U5MR). Scenarios for 2030 represent different potential trajectories, notably including potential effects of the COVID-19 pandemic and the potential impact of improvements preferentially targeting neonatal survival. Optimal child survival metrics were developed by age, sex, and cause of death across all GBD location-years. The first metric is a global optimum and is based on the lowest observed mortality, and the second is a survival potential frontier that is based on stochastic frontier analysis of observed mortality and Healthcare Access and Quality Index.

FINDINGS

Global U5MR decreased from 71·2 deaths per 1000 livebirths (95% uncertainty interval [UI] 68·3-74·0) in 2000 to 37·1 (33·2-41·7) in 2019 while global NMR correspondingly declined more slowly from 28·0 deaths per 1000 live births (26·8-29·5) in 2000 to 17·9 (16·3-19·8) in 2019. In 2019, 136 (67%) of 204 countries had a U5MR at or below the SDG 3.2 threshold and 133 (65%) had an NMR at or below the SDG 3.2 threshold, and the reference scenario suggests that by 2030, 154 (75%) of all countries could meet the U5MR targets, and 139 (68%) could meet the NMR targets. Deaths of children younger than 5 years totalled 9·65 million (95% UI 9·05-10·30) in 2000 and 5·05 million (4·27-6·02) in 2019, with the neonatal fraction of these deaths increasing from 39% (3·76 million [95% UI 3·53-4·02]) in 2000 to 48% (2·42 million; 2·06-2·86) in 2019. NMR and U5MR were generally higher in males than in females, although there was no statistically significant difference at the global level. Neonatal disorders remained the leading cause of death in children younger than 5 years in 2019, followed by lower respiratory infections, diarrhoeal diseases, congenital birth defects, and malaria. The global optimum analysis suggests NMR could be reduced to as low as 0·80 (95% UI 0·71-0·86) deaths per 1000 livebirths and U5MR to 1·44 (95% UI 1·27-1·58) deaths per 1000 livebirths, and in 2019, there were as many as 1·87 million (95% UI 1·35-2·58; 37% [95% UI 32-43]) of 5·05 million more deaths of children younger than 5 years than the survival potential frontier.

INTERPRETATION

Global child mortality declined by almost half between 2000 and 2019, but progress remains slower in neonates and 65 (32%) of 204 countries, mostly in sub-Saharan Africa and south Asia, are not on track to meet either SDG 3.2 target by 2030. Focused improvements in perinatal and newborn care, continued and expanded delivery of essential interventions such as vaccination and infection prevention, an enhanced focus on equity, continued focus on poverty reduction and education, and investment in strengthening health systems across the development spectrum have the potential to substantially improve U5MR. Given the widespread effects of COVID-19, considerable effort will be required to maintain and accelerate progress.

FUNDING

Bill & Melinda Gates Foundation.

Nano-based drug delivery systems used as vehicles to enhance polyphenols therapeutic effect for diabetes mellitus treatment

Diabetes mellitus is one of the biggest health emergencies of the 21^st century worldwide, characterized by deficiency in insulin secretion and/or action, leading to hyperglycemia. Despite the currently available antidiabetic therapeutic options, 4.2 million people died in 2019 due to diabetes. Thus, new effective interventions are required. Polyphenols are plant secondary metabolites and have been recognized for their vast number of biological activities, including potential antidiabetic effects. However, the poor bioavailability and high metabolization of polyphenols restrict their biological effects in vivo. Nanotechnology is a promising area of research to improve the therapeutic effect of several compounds. Therefore, this review provides an overview of the literature about the utility of nano-based drug delivery systems as vehicles of polyphenols in diabetes treatment. It was possible to conclude that, in general, nano-based drug delivery systems can potentiate the beneficial antidiabetic properties of polyphenols, when compared with the free compounds, opening a new field of research in diabetology.

The Effect of Chalcones on the Main Sources of Reactive Species Production: Possible Therapeutic Implications in Diabetes Mellitus

Diabetes mellitus (DM) is characterized by hyperglycaemia, resulting from defects in insulin secretion, insulin action or both. There are several factors such as hyperlipidemia and oxidative stress (OS), namely the production of reactive oxygen/nitrogen species (ROS/RNS), that actively contribute to the development and worsening of DM. Chalcones, also termed as benzalacetophenone or benzylidene acetophenone, present a 1,3-diaryl-2-propen-1-one scaffold that has been shown to be highly promising in the development of new antioxidant compounds. Considering the potential interest of antioxidant therapy, the present review scrutinizes the role of the main sources of ROS/RNS production during DM. The modulatory effect of chalcones against nicotinamide adenine dinucleotide phosphate (NADPH) oxidase, xanthine oxidase, mitochondrial respiratory chain and nitric oxide synthase, is also thoroughly discussed, establishing, whenever possible, a structure-activity relationship (SAR). From the SAR analysis, it can be stated that the presence of catechol groups, hydroxyl and methoxyl substituents in the chalcones scaffold improves their modulatory activity against the main sources of ROS/RNS production in DM.

Pyrazoles as novel protein tyrosine phosphatase 1B (PTP1B) inhibitors: An in vitro and in silico study

Type 2 diabetes mellitus (DM) is a complex chronic disorder and a major global health problem. Insulin resistance is the primary detectable abnormality and the main characteristic feature in individuals with type 2 DM. Protein tyrosine phosphatase 1B (PTP1B) is a key negative regulator of the insulin signaling pathway, which dephosphorylates insulin receptor and insulin receptor substrates, suppressing the insulin signaling cascade. Therefore, the inhibition of PTP1B has become a potential strategy in the management of type 2 DM. In this study, a library of 22 pyrazoles was evaluated here for the first time against human PTP1B activity, using a microanalysis screening system. The results showed that 5-(2-hydroxyphenyl)-3-{2-[3-(4-nitrophenyl)-1,2,3,4-tetrahydronaphthyl]}-1-phenylpyrazole 20 and 3-(2-hydroxyphenyl)-5-{2-[3-(4-methoxyphenyl)]naphthyl}pyrazole 22 excelled as the most potent inhibitors of PTP1B, through noncompetitive inhibition mechanism. These findings suggest that the presence of additional benzene rings as functional groups in the pyrazole moiety increases the ability of pyrazoles to inhibit PTP1B. The most active compounds showed selectivity over the homologous T-cell protein tyrosine phosphatase (TCPTP). Molecular docking analyses were performed and revealed a particular contact signature involving residues like TYR46, ASP48, PHE182, TYR46, ALA217 and ILE219. This study represents a significant beginning for the design of novel PTP1B inhibitors.

A comprehensive review on the antidiabetic activity of flavonoids targeting PTP1B and DPP-4: a structure-activity relationship analysis

Type 2 diabetes (T2D) is an expanding global health problem, resulting from defects in insulin secretion and/or insulin resistance. In the past few years, both protein tyrosine phosphatase 1B (PTP1B) and dipeptidyl peptidase-4 (DPP-4), as well as their role in T2D, have attracted the attention of the scientific community. PTP1B plays an important role in insulin resistance and is currently one of the most promising targets for the treatment of T2D, since no available PTP1B inhibitors were still approved. DPP-4 inhibitors are among the most recent agents used in the treatment of T2D (although its use has been associated with possible cardiovascular adverse events). The antidiabetic properties of flavonoids are well-recognized, and include inhibitory effects on the above enzymes, although hitherto not therapeutically explored. In the present study, a comprehensive review of the literature of both synthetic and natural isolated flavonoids as inhibitors of PTP1B and DPP-4 activities is made, including their type of inhibition and experimental conditions, and structure-activity relationship, covering a total of 351 compounds. We intend to provide the most favorable chemical features of flavonoids for the inhibition of PTP1B and DPP-4, gathering information for the future development of compounds with improved potential as T2D therapeutic agents.

Flavonoids as potential agents in the management of type 2 diabetes through the modulation of α-amylase and α-glucosidase activity: a review

Type 2 diabetes (T2D) is one of the most prevalent metabolic diseases worldwide and is characterized by increased postprandial hyperglycemia (PPHG). α-Amylase and α-glucosidase inhibitors have been shown to slow the release of glucose from starch and oligosaccharides, resulting in a delay of glucose absorption and a reduction in postprandial blood glucose levels. Since current α-glucosidase inhibitors used in the management of T2D, such as acarbose, have been associated to strong gastrointestinal side effects, the search for novel and safer drugs is considered a hot topic of research. Flavonoids are phenolic compounds widely distributed in the Plant Kingdom and important components of the human diet. These compounds have shown promising antidiabetic activities, including the inhibition of α-amylase and α-glucosidase. The aim of this review is to provide an overview on the scientific literature concerning the structure-activity relationship of flavonoids in inhibiting α-amylase and α-glucosidase, including their type of inhibition and experimental procedures applied. For this purpose, a total of 500 compounds is covered in this review. Available data may be considered of high value for the design and development of novel flavonoid derivatives with effective and potent inhibitory activity against those carbohydrate-hydrolyzing enzymes, to be possibly used as safer alternatives for the regulation of PPHG in T2D.

Chalcones as Modulators of Neutrophil Oxidative Burst under Physiological and High Glucose Conditions

Several epidemiological studies indicate that neutrophils, under hyperglycemic conditions, are involved in the perpetuation of the inflammatory status, a characteristic of diabetes mellitus, leading to the production of prodigious quantities of reactive species and the release of neutrophil extracellular traps (NETs). Accordingly, our aim was to study the ability of a panel of 25 structurally related chalcones to modulate human neutrophil oxidative burst and the production of NETs under physiological and high glucose conditions. In general, all chalcones presented similar effects under physiological and high glucose conditions. 2',4-Dihydroxy-3-methoxychalcone (3), here studied for the first time, was the most active (IC₅₀ ≤ 5 μM) on the inhibition of neutrophil oxidative burst, showing the importance of the presence of hydroxy substituents at the C-2' and C-4 positions of the A and B rings, respectively, and a 3-methoxy substituent at B ring of the chalcone scaffold. In the present experimental conditions, NETs release only occurred under high glucose levels. The pentahydroxylated chalcone 1 was the only one that was able to modulate the NETs release. This study provided important considerations about the chalcones' scaffold and their modulatory effect on human neutrophil activities at physiological and high glucose conditions, evidencing their potential use as complementary antidiabetic agents.

Global burden of 369 diseases and injuries in 204 countries and territories, 1990-2019: a systematic analysis for the Global Burden of Disease Study 2019

BACKGROUND

In an era of shifting global agendas and expanded emphasis on non-communicable diseases and injuries along with communicable diseases, sound evidence on trends by cause at the national level is essential. The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) provides a systematic scientific assessment of published, publicly available, and contributed data on incidence, prevalence, and mortality for a mutually exclusive and collectively exhaustive list of diseases and injuries.

METHODS

GBD estimates incidence, prevalence, mortality, years of life lost (YLLs), years lived with disability (YLDs), and disability-adjusted life-years (DALYs) due to 369 diseases and injuries, for two sexes, and for 204 countries and territories. Input data were extracted from censuses, household surveys, civil registration and vital statistics, disease registries, health service use, air pollution monitors, satellite imaging, disease notifications, and other sources. Cause-specific death rates and cause fractions were calculated using the Cause of Death Ensemble model and spatiotemporal Gaussian process regression. Cause-specific deaths were adjusted to match the total all-cause deaths calculated as part of the GBD population, fertility, and mortality estimates. Deaths were multiplied by standard life expectancy at each age to calculate YLLs. A Bayesian meta-regression modelling tool, DisMod-MR 2.1, was used to ensure consistency between incidence, prevalence, remission, excess mortality, and cause-specific mortality for most causes. Prevalence estimates were multiplied by disability weights for mutually exclusive sequelae of diseases and injuries to calculate YLDs. We considered results in the context of the Socio-demographic Index (SDI), a composite indicator of income per capita, years of schooling, and fertility rate in females younger than 25 years. Uncertainty intervals (UIs) were generated for every metric using the 25th and 975th ordered 1000 draw values of the posterior distribution.

FINDINGS

Global health has steadily improved over the past 30 years as measured by age-standardised DALY rates. After taking into account population growth and ageing, the absolute number of DALYs has remained stable. Since 2010, the pace of decline in global age-standardised DALY rates has accelerated in age groups younger than 50 years compared with the 1990-2010 time period, with the greatest annualised rate of decline occurring in the 0-9-year age group. Six infectious diseases were among the top ten causes of DALYs in children younger than 10 years in 2019: lower respiratory infections (ranked second), diarrhoeal diseases (third), malaria (fifth), meningitis (sixth), whooping cough (ninth), and sexually transmitted infections (which, in this age group, is fully accounted for by congenital syphilis; ranked tenth). In adolescents aged 10-24 years, three injury causes were among the top causes of DALYs: road injuries (ranked first), self-harm (third), and interpersonal violence (fifth). Five of the causes that were in the top ten for ages 10-24 years were also in the top ten in the 25-49-year age group: road injuries (ranked first), HIV/AIDS (second), low back pain (fourth), headache disorders (fifth), and depressive disorders (sixth). In 2019, ischaemic heart disease and stroke were the top-ranked causes of DALYs in both the 50-74-year and 75-years-and-older age groups. Since 1990, there has been a marked shift towards a greater proportion of burden due to YLDs from non-communicable diseases and injuries. In 2019, there were 11 countries where non-communicable disease and injury YLDs constituted more than half of all disease burden. Decreases in age-standardised DALY rates have accelerated over the past decade in countries at the lower end of the SDI range, while improvements have started to stagnate or even reverse in countries with higher SDI.

INTERPRETATION

As disability becomes an increasingly large component of disease burden and a larger component of health expenditure, greater research and development investment is needed to identify new, more effective intervention strategies. With a rapidly ageing global population, the demands on health services to deal with disabling outcomes, which increase with age, will require policy makers to anticipate these changes. The mix of universal and more geographically specific influences on health reinforces the need for regular reporting on population health in detail and by underlying cause to help decision makers to identify success stories of disease control to emulate, as well as opportunities to improve.

FUNDING

Bill & Melinda Gates Foundation.

Global burden of 87 risk factors in 204 countries and territories, 1990-2019: a systematic analysis for the Global Burden of Disease Study 2019

BACKGROUND

Rigorous analysis of levels and trends in exposure to leading risk factors and quantification of their effect on human health are important to identify where public health is making progress and in which cases current efforts are inadequate. The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019 provides a standardised and comprehensive assessment of the magnitude of risk factor exposure, relative risk, and attributable burden of disease.

METHODS

GBD 2019 estimated attributable mortality, years of life lost (YLLs), years of life lived with disability (YLDs), and disability-adjusted life-years (DALYs) for 87 risk factors and combinations of risk factors, at the global level, regionally, and for 204 countries and territories. GBD uses a hierarchical list of risk factors so that specific risk factors (eg, sodium intake), and related aggregates (eg, diet quality), are both evaluated. This method has six analytical steps. (1) We included 560 risk-outcome pairs that met criteria for convincing or probable evidence on the basis of research studies. 12 risk-outcome pairs included in GBD 2017 no longer met inclusion criteria and 47 risk-outcome pairs for risks already included in GBD 2017 were added based on new evidence. (2) Relative risks were estimated as a function of exposure based on published systematic reviews, 81 systematic reviews done for GBD 2019, and meta-regression. (3) Levels of exposure in each age-sex-location-year included in the study were estimated based on all available data sources using spatiotemporal Gaussian process regression, DisMod-MR 2.1, a Bayesian meta-regression method, or alternative methods. (4) We determined, from published trials or cohort studies, the level of exposure associated with minimum risk, called the theoretical minimum risk exposure level. (5) Attributable deaths, YLLs, YLDs, and DALYs were computed by multiplying population attributable fractions (PAFs) by the relevant outcome quantity for each age-sex-location-year. (6) PAFs and attributable burden for combinations of risk factors were estimated taking into account mediation of different risk factors through other risk factors. Across all six analytical steps, 30 652 distinct data sources were used in the analysis. Uncertainty in each step of the analysis was propagated into the final estimates of attributable burden. Exposure levels for dichotomous, polytomous, and continuous risk factors were summarised with use of the summary exposure value to facilitate comparisons over time, across location, and across risks. Because the entire time series from 1990 to 2019 has been re-estimated with use of consistent data and methods, these results supersede previously published GBD estimates of attributable burden.

FINDINGS

The largest declines in risk exposure from 2010 to 2019 were among a set of risks that are strongly linked to social and economic development, including household air pollution; unsafe water, sanitation, and handwashing; and child growth failure. Global declines also occurred for tobacco smoking and lead exposure. The largest increases in risk exposure were for ambient particulate matter pollution, drug use, high fasting plasma glucose, and high body-mass index. In 2019, the leading Level 2 risk factor globally for attributable deaths was high systolic blood pressure, which accounted for 10·8 million (95% uncertainty interval [UI] 9·51-12·1) deaths (19·2% [16·9-21·3] of all deaths in 2019), followed by tobacco (smoked, second-hand, and chewing), which accounted for 8·71 million (8·12-9·31) deaths (15·4% [14·6-16·2] of all deaths in 2019). The leading Level 2 risk factor for attributable DALYs globally in 2019 was child and maternal malnutrition, which largely affects health in the youngest age groups and accounted for 295 million (253-350) DALYs (11·6% [10·3-13·1] of all global DALYs that year). The risk factor burden varied considerably in 2019 between age groups and locations. Among children aged 0-9 years, the three leading detailed risk factors for attributable DALYs were all related to malnutrition. Iron deficiency was the leading risk factor for those aged 10-24 years, alcohol use for those aged 25-49 years, and high systolic blood pressure for those aged 50-74 years and 75 years and older.

INTERPRETATION

Overall, the record for reducing exposure to harmful risks over the past three decades is poor. Success with reducing smoking and lead exposure through regulatory policy might point the way for a stronger role for public policy on other risks in addition to continued efforts to provide information on risk factor harm to the general public.

FUNDING

Bill & Melinda Gates Foundation.

Global age-sex-specific fertility, mortality, healthy life expectancy (HALE), and population estimates in 204 countries and territories, 1950-2019: a comprehensive demographic analysis for the Global Burden of Disease Study 2019

BACKGROUND

Accurate and up-to-date assessment of demographic metrics is crucial for understanding a wide range of social, economic, and public health issues that affect populations worldwide. The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019 produced updated and comprehensive demographic assessments of the key indicators of fertility, mortality, migration, and population for 204 countries and territories and selected subnational locations from 1950 to 2019.

METHODS

8078 country-years of vital registration and sample registration data, 938 surveys, 349 censuses, and 238 other sources were identified and used to estimate age-specific fertility. Spatiotemporal Gaussian process regression (ST-GPR) was used to generate age-specific fertility rates for 5-year age groups between ages 15 and 49 years. With extensions to age groups 10-14 and 50-54 years, the total fertility rate (TFR) was then aggregated using the estimated age-specific fertility between ages 10 and 54 years. 7417 sources were used for under-5 mortality estimation and 7355 for adult mortality. ST-GPR was used to synthesise data sources after correction for known biases. Adult mortality was measured as the probability of death between ages 15 and 60 years based on vital registration, sample registration, and sibling histories, and was also estimated using ST-GPR. HIV-free life tables were then estimated using estimates of under-5 and adult mortality rates using a relational model life table system created for GBD, which closely tracks observed age-specific mortality rates from complete vital registration when available. Independent estimates of HIV-specific mortality generated by an epidemiological analysis of HIV prevalence surveys and antenatal clinic serosurveillance and other sources were incorporated into the estimates in countries with large epidemics. Annual and single-year age estimates of net migration and population for each country and territory were generated using a Bayesian hierarchical cohort component model that analysed estimated age-specific fertility and mortality rates along with 1250 censuses and 747 population registry years. We classified location-years into seven categories on the basis of the natural rate of increase in population (calculated by subtracting the crude death rate from the crude birth rate) and the net migration rate. We computed healthy life expectancy (HALE) using years lived with disability (YLDs) per capita, life tables, and standard demographic methods. Uncertainty was propagated throughout the demographic estimation process, including fertility, mortality, and population, with 1000 draw-level estimates produced for each metric.

FINDINGS

The global TFR decreased from 2·72 (95% uncertainty interval [UI] 2·66-2·79) in 2000 to 2·31 (2·17-2·46) in 2019. Global annual livebirths increased from 134·5 million (131·5-137·8) in 2000 to a peak of 139·6 million (133·0-146·9) in 2016. Global livebirths then declined to 135·3 million (127·2-144·1) in 2019. Of the 204 countries and territories included in this study, in 2019, 102 had a TFR lower than 2·1, which is considered a good approximation of replacement-level fertility. All countries in sub-Saharan Africa had TFRs above replacement level in 2019 and accounted for 27·1% (95% UI 26·4-27·8) of global livebirths. Global life expectancy at birth increased from 67·2 years (95% UI 66·8-67·6) in 2000 to 73·5 years (72·8-74·3) in 2019. The total number of deaths increased from 50·7 million (49·5-51·9) in 2000 to 56·5 million (53·7-59·2) in 2019. Under-5 deaths declined from 9·6 million (9·1-10·3) in 2000 to 5·0 million (4·3-6·0) in 2019. Global population increased by 25·7%, from 6·2 billion (6·0-6·3) in 2000 to 7·7 billion (7·5-8·0) in 2019. In 2019, 34 countries had negative natural rates of increase; in 17 of these, the population declined because immigration was not sufficient to counteract the negative rate of decline. Globally, HALE increased from 58·6 years (56·1-60·8) in 2000 to 63·5 years (60·8-66·1) in 2019. HALE increased in 202 of 204 countries and territories between 2000 and 2019.

INTERPRETATION

Over the past 20 years, fertility rates have been dropping steadily and life expectancy has been increasing, with few exceptions. Much of this change follows historical patterns linking social and economic determinants, such as those captured by the GBD Socio-demographic Index, with demographic outcomes. More recently, several countries have experienced a combination of low fertility and stagnating improvement in mortality rates, pushing more populations into the late stages of the demographic transition. Tracking demographic change and the emergence of new patterns will be essential for global health monitoring.

FUNDING

Bill & Melinda Gates Foundation.

OMICs Approaches in Diarrhetic Shellfish Toxins Research

Diarrhetic shellfish toxins (DSTs) are among the most prevalent marine toxins in Europe's and in other temperate coastal regions. These toxins are produced by several dinoflagellate species; however, the contamination of the marine trophic chain is often attributed to species of the genus Dinophysis. This group of toxins, constituted by okadaic acid (OA) and analogous molecules (dinophysistoxins, DTXs), are highly harmful to humans, causing severe poisoning symptoms caused by the ingestion of contaminated seafood. Knowledge on the mode of action and toxicology of OA and the chemical characterization and accumulation of DSTs in seafood species (bivalves, gastropods and crustaceans) has significantly contributed to understand the impacts of these toxins in humans. Considerable information is however missing, particularly at the molecular and metabolic levels involving toxin uptake, distribution, compartmentalization and biotransformation and the interaction of DSTs with aquatic organisms. Recent contributions to the knowledge of DSTs arise from transcriptomics and proteomics research. Indeed, OMICs constitute a research field dedicated to the systematic analysis on the organisms' metabolisms. The methodologies used in OMICs are also highly effective to identify critical metabolic pathways affecting the physiology of the organisms. In this review, we analyze the main contributions provided so far by OMICs to DSTs research and discuss the prospects of OMICs with regard to the DSTs toxicology and the significance of these toxins to public health, food safety and aquaculture.

A Systematic Review on Anti-diabetic Properties of Chalcones

The use of anti-diabetic drugs has been increasing worldwide and the evolution of therapeutics has been enormous. Still, the currently available anti-diabetic drugs do not present the desired efficacy and are generally associated with serious adverse effects. Thus, entirely new interventions, addressing the underlying etiopathogenesis of type 2 diabetes mellitus, are required. Chalcones, secondary metabolites of terrestrial plants and precursors of the flavonoids biosynthesis, have been used for a long time in traditional medicine due to their wide-range of biological activities, from which the anti-diabetic activity stands out. This review systematizes the information found in literature about the anti-diabetic properties of chalcones, in vitro and in vivo. Chalcones are able to exert these properties by acting in different therapeutic targets: Dipeptidyl Peptidase 4 (DPP-4); Glucose Transporter Type 4 (GLUT4), Sodium Glucose Cotransporter 2 (SGLT2), α-amylase, α-glucosidase, Aldose Reductase (ALR), Protein Tyrosine Phosphatase 1B (PTP1B), Peroxisome Proliferator-activated Receptor-gamma (PPARγ) and Adenosine Monophosphate (AMP)-activated Protein Kinase (AMPK). Chalcones are, undoubtedly, promising anti-diabetic agents, and some crucial structural features have already been established. From the Structure-Activity Relationships analysis, it can generally be stated that the presence of hydroxyl, prenyl and geranyl groups in their skeleton improves their activity for the evaluated anti-diabetic targets.

Structural Specificity of Flavonoids in the Inhibition of Human Fructose 1,6-Bisphosphatase

Liver fructose 1,6-bisphosphatase (FBPase) is a recognized regulatory enzyme of the gluconeogenesis pathway, which has emerged as a valid target to control gluconeogenesis-mediated overproduction of glucose. As such, the management of diabetes with FBPase inhibitors represents a potential alternative for the currently used antidiabetic agents. In this study, the FBPase inhibition of a panel of 55 structurally related flavonoids was tested, through a microanalysis screening system. Then, a subset of seven active inhibitors and their close chemical relatives were further evaluated by molecular dynamics (MD) simulations using a linear interaction energy (LIE) approach. The results obtained showed that D14 (herbacetin) was the most potent inhibitor, suggesting that the presence of -OH groups at the C-3, C-4', C-5, C-7, and C-8 positions, as well as the double bond between C-2 and C-3 and the 4-oxo function at the pyrone ring, are favorable for the intended effect. Furthermore, D14 (herbacetin) is stabilized by a strong interaction with the Glu30 side chain and the Thr24 backbone of FBPase. This is the first investigation studying the in vitro inhibitory effect of a panel of flavonoids against human liver FBPase, thus representing a potentially important step for the search and design of novel inhibitors of this enzyme.

β-Carotene and its physiological metabolites: Effects on oxidative status regulation and genotoxicity in in vitro models

Carotenoids are ubiquitously distributed in nature, β-carotene being the most frequently found carotenoid in the human diet. In the human body, β-carotene is absorbed, distributed and metabolized by enzymatic and/or non-enzymatic oxidant cleavage into several metabolites. Despite the broadly accepted biological value of β-carotene, it has also been considered a double-edged sword, mainly due to its potential antioxidant versus pro-oxidant behaviour. In this sense, the aim of this work was to scrutinize the antioxidant or pro-oxidant potential of β-carotene and its metabolites, namely trans-β-apo-8'-carotenal and β-ionone. Several parameters were evaluated in this study, viz. their effects on reactive species production, both in human whole blood and neutrophils; their effects on lipid peroxidation, in the absence and presence of peroxynitrite anion (ONOO^-) or hydrogen peroxide (H₂O₂), using a synaptosomal model; and finally, their putative genotoxic effects in the human hepatic HepG2 cell line. In general, depending on the cellular model and conditions tested, β-carotene and its metabolites revealed antioxidant effects to varying degrees without significant pro-oxidant or genotoxic effects.

Global, regional, and national burden of chronic kidney disease, 1990-2017: a systematic analysis for the Global Burden of Disease Study 2017

BACKGROUND

Health system planning requires careful assessment of chronic kidney disease (CKD) epidemiology, but data for morbidity and mortality of this disease are scarce or non-existent in many countries. We estimated the global, regional, and national burden of CKD, as well as the burden of cardiovascular disease and gout attributable to impaired kidney function, for the Global Burden of Diseases, Injuries, and Risk Factors Study 2017. We use the term CKD to refer to the morbidity and mortality that can be directly attributed to all stages of CKD, and we use the term impaired kidney function to refer to the additional risk of CKD from cardiovascular disease and gout.

METHODS

The main data sources we used were published literature, vital registration systems, end-stage kidney disease registries, and household surveys. Estimates of CKD burden were produced using a Cause of Death Ensemble model and a Bayesian meta-regression analytical tool, and included incidence, prevalence, years lived with disability, mortality, years of life lost, and disability-adjusted life-years (DALYs). A comparative risk assessment approach was used to estimate the proportion of cardiovascular diseases and gout burden attributable to impaired kidney function.

FINDINGS

Globally, in 2017, 1·2 million (95% uncertainty interval [UI] 1·2 to 1·3) people died from CKD. The global all-age mortality rate from CKD increased 41·5% (95% UI 35·2 to 46·5) between 1990 and 2017, although there was no significant change in the age-standardised mortality rate (2·8%, -1·5 to 6·3). In 2017, 697·5 million (95% UI 649·2 to 752·0) cases of all-stage CKD were recorded, for a global prevalence of 9·1% (8·5 to 9·8). The global all-age prevalence of CKD increased 29·3% (95% UI 26·4 to 32·6) since 1990, whereas the age-standardised prevalence remained stable (1·2%, -1·1 to 3·5). CKD resulted in 35·8 million (95% UI 33·7 to 38·0) DALYs in 2017, with diabetic nephropathy accounting for almost a third of DALYs. Most of the burden of CKD was concentrated in the three lowest quintiles of Socio-demographic Index (SDI). In several regions, particularly Oceania, sub-Saharan Africa, and Latin America, the burden of CKD was much higher than expected for the level of development, whereas the disease burden in western, eastern, and central sub-Saharan Africa, east Asia, south Asia, central and eastern Europe, Australasia, and western Europe was lower than expected. 1·4 million (95% UI 1·2 to 1·6) cardiovascular disease-related deaths and 25·3 million (22·2 to 28·9) cardiovascular disease DALYs were attributable to impaired kidney function.

INTERPRETATION

Kidney disease has a major effect on global health, both as a direct cause of global morbidity and mortality and as an important risk factor for cardiovascular disease. CKD is largely preventable and treatable and deserves greater attention in global health policy decision making, particularly in locations with low and middle SDI.

FUNDING

Bill & Melinda Gates Foundation.

Global, Regional, and National Cancer Incidence, Mortality, Years of Life Lost, Years Lived With Disability, and Disability-Adjusted Life-Years for 29 Cancer Groups, 1990 to 2017: A Systematic Analysis for the Global Burden of Disease Study

Importance

Cancer and other noncommunicable diseases (NCDs) are now widely recognized as a threat to global development. The latest United Nations high-level meeting on NCDs reaffirmed this observation and also highlighted the slow progress in meeting the 2011 Political Declaration on the Prevention and Control of Noncommunicable Diseases and the third Sustainable Development Goal. Lack of situational analyses, priority setting, and budgeting have been identified as major obstacles in achieving these goals. All of these have in common that they require information on the local cancer epidemiology. The Global Burden of Disease (GBD) study is uniquely poised to provide these crucial data.

Objective

To describe cancer burden for 29 cancer groups in 195 countries from 1990 through 2017 to provide data needed for cancer control planning.

Evidence Review

We used the GBD study estimation methods to describe cancer incidence, mortality, years lived with disability, years of life lost, and disability-adjusted life-years (DALYs). Results are presented at the national level as well as by Socio-demographic Index (SDI), a composite indicator of income, educational attainment, and total fertility rate. We also analyzed the influence of the epidemiological vs the demographic transition on cancer incidence.

Findings

In 2017, there were 24.5 million incident cancer cases worldwide (16.8 million without nonmelanoma skin cancer [NMSC]) and 9.6 million cancer deaths. The majority of cancer DALYs came from years of life lost (97%), and only 3% came from years lived with disability. The odds of developing cancer were the lowest in the low SDI quintile (1 in 7) and the highest in the high SDI quintile (1 in 2) for both sexes. In 2017, the most common incident cancers in men were NMSC (4.3 million incident cases); tracheal, bronchus, and lung (TBL) cancer (1.5 million incident cases); and prostate cancer (1.3 million incident cases). The most common causes of cancer deaths and DALYs for men were TBL cancer (1.3 million deaths and 28.4 million DALYs), liver cancer (572 000 deaths and 15.2 million DALYs), and stomach cancer (542 000 deaths and 12.2 million DALYs). For women in 2017, the most common incident cancers were NMSC (3.3 million incident cases), breast cancer (1.9 million incident cases), and colorectal cancer (819 000 incident cases). The leading causes of cancer deaths and DALYs for women were breast cancer (601 000 deaths and 17.4 million DALYs), TBL cancer (596 000 deaths and 12.6 million DALYs), and colorectal cancer (414 000 deaths and 8.3 million DALYs).

Conclusions and Relevance

The national epidemiological profiles of cancer burden in the GBD study show large heterogeneities, which are a reflection of different exposures to risk factors, economic settings, lifestyles, and access to care and screening. The GBD study can be used by policy makers and other stakeholders to develop and improve national and local cancer control in order to achieve the global targets and improve equity in cancer care.

Analysis of the Use of Cylindrospermopsin and/or Microcystin-Contaminated Water in the Growth, Mineral Content, and Contamination of Spinacia oleracea and Lactuca sativa

Cyanobacteria and cyanotoxins constitute a serious environmental and human health problem. Moreover, concerns are raised with the use of contaminated water in agriculture and vegetable production as this can lead to food contamination and human exposure to toxins as well as impairment in crop development and productivity. The objective of this work was to assess the susceptibility of two green vegetables, spinach and lettuce, to the cyanotoxins microcystin (MC) and cylindrospermopsin (CYN), individually and in mixture. The study consisted of growing both vegetables in hydroponics, under controlled conditions, for 21 days in nutrient medium doped with MC or CYN at 10 μg/L and 50 μg/L, or CYN/MC mixture at 5 + 5 μg/L and 25 + 25 μg/L. Extracts from M. aeruginosa and C. ovalisporum were used as sources of toxins. The study revealed growth inhibition of the aerial part (Leaves) in both species when treated with 50µg/L of MC, CYN and CYN/MC mixture. MC showed to be more harmful to plant growth than CYN. Moreover spinach leaves growth was inhibited by both 5 + 5 and 25 + 25 µg/L CYN/MC mixtures, whereas lettuce leaves growth was inhibited only by 25 + 25 µg/L CYN/MC mixture. Overall, growth data evidence increased sensitivity of spinach to cyanotoxins in comparison to lettuce. On the other hand, plants exposed to CYN/MC mixture showed differential accumulation of CYN and MC. In addition, CYN, but not MC, was translocated from the roots to the leaves. CYN and MC affected the levels of minerals particularly in plant roots. The elements most affected were Ca, K and Mg. However, in leaves K was the mineral that was affected by exposure to cyanotoxins.

The dipeptidyl peptidase-4 inhibitory effect of flavonoids is hindered in protein rich environments

Dipeptidyl peptidase-4 (DPP-4) inhibitors present a unique approach for the management of type 2 diabetes (T2D). In the present study, the inhibition of DPP-4 was evaluated for a large panel of flavonoids, important components of the human diet, using in vitro and ex vivo models. The activity of the isolated enzyme was assayed in vitro. Subsequently, the most active flavonoids were tested ex vivo in human whole blood and plasma. In this study, contrary to the in vitro fluorometric tests, flavonoids did not show inhibitory activity against DPP-4. Due to the discrepancy in the results between the in vitro and ex vivo approaches, plasma protein binding values were determined, presenting values from 43.9 to 100.0%. This work provides a new insight into the inhibitory activity for DPP-4, based on the flavonoid scaffold. Additionally, the obtained results showed that the inhibitory effect of flavonoids against DPP-4 was hindered in protein rich environments, like that occurring in blood, and indicated the need for experimental refinement in drug discovery for blood targets.

A study towards drug discovery for the management of type 2 diabetes mellitus through inhibition of the carbohydrate-hydrolyzing enzymes α-amylase and α-glucosidase by chalcone derivatives

The inhibition of carbohydrate-hydrolyzing enzymes, α-amylase and α-glucosidase, is one of the major therapeutic strategies for the treatment of type 2 diabetes mellitus. Chalcones have been recognized for their multiple biological activities, including antidiabetic properties, through unclear mechanisms. In the present work, a panel of chalcones bearing hydroxy, methoxy, methyl, nitro, chloro, fluoro and bromo substituents were evaluated against α-amylase and α-glucosidase activities, most of them for the first time. The results showed that the substitution patterns and the type of substituents of chalcones influence their inhibitory activity. The presence of hydroxy groups at C-2'- and C-4' of the A ring and at C-3 and C-4 of the B ring favors the intended effect. Chalcones holding nitro groups and chloro substituents, together with a hydroxy group in the chalcone scaffold, showed strong inhibition of the α-glucosidase activity. The present study provides related scaffolds that may serve as the basis for the design and synthesis of new structures in order to obtain the ideal antidiabetic chalcone.

Evaluation of a flavonoids library for inhibition of pancreatic α-amylase towards a structure-activity relationship

α-Amylase has been considered an important therapeutic target for the management of type 2 diabetes mellitus (T2DM), decreasing postprandial hyperglycaemia (PPHG). In the present work, a panel of 40 structurally related flavonoids was tested, concerning their ability to inhibit α-amylase activity, using a microanalysis screening system, an inhibitory kinetic analysis and molecular docking calculations. From the obtained results, it was possible to observe that the flavone with a -Cl ion at 3-position of C-ring, an –OH group at 3′- and 4′- positions of B-ring and at 5- and 7- positions of A-ring and the C2 = C3 double bond, was the most active tested flavonoid, through competitive inhibition. In conclusion, some of the tested flavonoids have shown promising inhibition of α-amylase and may be considered as possible alternatives to the modulation of T2DM.

Correction: A study towards drug discovery for the management of type 2 diabetes mellitus through inhibition of the carbohydrate-hydrolyzing enzymes α-amylase and α-glucosidase by chalcone derivatives

Correction for ‘A study towards drug discovery for the management of type 2 diabetes mellitus through inhibition of the carbohydrate-hydrolyzing enzymes α-amylase and α-glucosidase by chalcone derivatives’ by Sónia Rocha, et al., Food Funct., 2019, DOI: 10.1039/c9fo01298b.

Calcium Pathways in Human Neutrophils-The Extended Effects of Thapsigargin and ML-9

In neutrophils, intracellular Ca²⁺ levels are regulated by several transporters and pathways, namely SERCA [sarco(endo)plasmic reticulum Ca²⁺-ATPase], SOCE (store-operated calcium entry), and ROCE (receptor-operated calcium entry). However, the exact mechanisms involved in the communication among these transporters are still unclear. In the present study, thapsigargin, an irreversible inhibitor of SERCA, and ML-9, a broadly used SOCE inhibitor, were applied in human neutrophils to better understand their effects on Ca²⁺ pathways in these important cells of the immune system. The thapsigargin and ML-9 effects in the intracellular free Ca²⁺ flux were evaluated in freshly isolated human neutrophils, using a microplate reader for monitoring fluorimetric kinetic readings. The obtained results corroborate the general thapsigargin-induced intracellular pattern of Ca²⁺ fluctuation, but it was also observed a much more extended effect in time and a clear sustained increase of Ca²⁺ levels due to its influx by SOCE. Moreover, it was obvious that ML-9 enhanced the thapsigargin-induced emptying of the internal stores. Indeed, ML-9 does not have this effect by itself, which indicates that, in neutrophils, thapsigargin does not act only on the influx by SOCE, but also by other Ca²⁺ pathways, that, in the future, should be further explored.