NAFLD in the 21st Century: Current Knowledge Regarding Its Pathogenesis, Diagnosis and Therapeutics

Non-alcoholic fatty liver disease (NAFLD) is a major public health issue worldwide. It is the most common liver disease in Western countries, andits global prevalence is estimated to be up to 35%. However, its diagnosis may be elusive, because liver biopsy is relatively rarely performed and usually only in advanced stages of the disease. Therefore, several non-invasive scores may be applied to more easily diagnose and monitor NAFLD. In this review, we discuss the various biomarkers and imaging scores that could be useful in diagnosing and managing NAFLD. Despite the fact that general measures, such as abstinence from alcohol and modulation of other cardiovascular disease risk factors, should be applied, the mainstay of prevention and management is weight loss. Bariatric surgery may be suggested as a means to confront NAFLD. In addition, pharmacological treatment with GLP-1 analogues or the GIP agonist tirzepatide may be advisable. In this review, we focus on the utility of GLP-1 analogues and GIP agonists in lowering body weight, their pharmaceutical potential, and their safety profile, as already evidenced inanimal and human studies. We also elaborate on other options, such as the use of vitamin E, probiotics, especially next-generation probiotics, and prebiotics in this context. Finally, we explore future perspectives regarding the administration of GLP-1 analogues, GIP agonists, and probiotics/prebiotics as a means to prevent and combat NAFLD. The newest drugs pegozafermin and resmetiron, which seem to be very promising, arealso discussed.

Obesity and Leukemia: Biological Mechanisms, Perspectives, and Challenges

PURPOSE OF REVIEW

To examine the epidemiological data on obesity and leukemia; evaluate the effect of obesity on leukemia outcomes in childhood acute lymphoblastic leukemia (ALL) survivors; assess the potential mechanisms through which obesity may increase the risk of leukemia; and provide the effects of obesity management on leukemia. Preventive (diet, physical exercise, obesity pharmacotherapy, bariatric surgery) measures, repurposing drugs, candidate therapeutic agents targeting oncogenic pathways of obesity and insulin resistance in leukemia as well as challenges of the COVID-19 pandemic are also discussed.

RECENT FINDINGS

Obesity has been implicated in the development of 13 cancers, such as breast, endometrial, colon, renal, esophageal cancers, and multiple myeloma. Leukemia is estimated to account for approximately 2.5% and 3.1% of all new cancer incidence and mortality, respectively, while it represents the most frequent cancer in children younger than 5 years. Current evidence indicates that obesity may have an impact on the risk of leukemia. Increased birthweight may be associated with the development of childhood leukemia. Obesity is also associated with worse outcomes and increased mortality in leukemic patients. However, there are several limitations and challenges in meta-analyses and epidemiological studies. In addition, weight gain may occur in a substantial number of childhood ALL survivors while the majority of studies have documented an increased risk of relapse and mortality among patients with childhood ALL and obesity. The main pathophysiological pathways linking obesity to leukemia include bone marrow adipose tissue; hormones such as insulin and the insulin-like growth factor system as well as sex hormones; pro-inflammatory cytokines, such as IL-6 and TNF-α; adipocytokines, such as adiponectin, leptin, resistin, and visfatin; dyslipidemia and lipid signaling; chronic low-grade inflammation and oxidative stress; and other emerging mechanisms. Obesity represents a risk factor for leukemia, being among the only known risk factors that could be prevented or modified through weight loss, healthy diet, and physical exercise. Pharmacological interventions, repurposing drugs used for cardiometabolic comorbidities, and bariatric surgery may be recommended for leukemia and obesity-related cancer prevention.

The Interplay Between Dietary Choline and Cardiometabolic Disorders: A Review of Current Evidence

PURPOSE OF REVIEW

Choline is an essential nutrient for human health and cellular homeostasis as it is necessary for the synthesis of lipid cell membranes, lipoproteins, and the synthesis of the neurotransmitter acetylcholine. The aim of this review is to analyze the beneficial effects of choline and its significance in cellular metabolism and various inflammatory pathways, such as the inflammasome. We will discuss the significance of dietary choline in cardiometabolic disorders, such as non-alcoholic fatty liver disease (NAFLD), cardiovascular disease (CVD), and chronic kidney disease (CKD) as well as in cognitive function and associated neuropsychiatric disorders.

RECENT FINDINGS

Choline deficiency has been related to the development of NAFLD and cognitive disability in the offspring as well as in adulthood. In sharp contrast, excess dietary intake of choline mediated via the increased production of trimethylamine by the gut microbiota and increased trimethylamine-N-oxide (TMAO) levels has been related to atherosclerosis in most studies. In this context, CVD and CKD through the accumulation of TMAO, p-Cresyl-sulfate (pCS), and indoxyl-sulfate (IS) in serum may be the result of the interplay between excess dietary choline, the increased production of TMAO by the gut microbiota, and the resulting activation of inflammatory responses and fibrosis. A balanced diet, with no excess nor any deficiency in dietary choline, is of outmost importance regarding the prevention of cardiometabolic disorders as well as cognitive function. Large-scale studies with the use of next-generation probiotics, especially Akkermansia muciniphila and Faecalibacterium prausnitzii, should further examine their therapeutic potential in this context.

ApoB100 and Atherosclerosis: What's New in the 21st Century?

ApoB is the main protein of triglyceride-rich lipoproteins and is further divided into ApoB48 in the intestine and ApoB100 in the liver. Very low-density lipoprotein (VLDL) is produced by the liver, contains ApoB100, and is metabolized into its remnants, intermediate-density lipoprotein (IDL) and low-density lipoprotein (LDL). ApoB100 has been suggested to play a crucial role in the formation of the atherogenic plaque. Apart from being a biomarker of atherosclerosis, ApoB100 seems to be implicated in the inflammatory process of atherosclerosis per se. In this review, we will focus on the structure, the metabolism, and the function of ApoB100, as well as its role as a predictor biomarker of cardiovascular risk. Moreover, we will elaborate upon the molecular mechanisms regarding the pathophysiology of atherosclerosis, and we will discuss the disorders associated with the APOB gene mutations, and the potential role of various drugs as therapeutic targets.

The Role of Endocrine Disruptors Bisphenols and Phthalates in Obesity: Current Evidence, Perspectives and Controversies

Excess body weight constitutes one of the major health challenges for societies and healthcare systems worldwide. Besides the type of diet, calorie intake and the lack of physical exercise, recent data have highlighted a possible association between endocrine-disrupting chemicals (EDCs), such as bisphenol A, phthalates and their analogs, and obesity. EDCs represent a heterogeneous group of chemicals that may influence the hormonal regulation of body mass and adipose tissue morphology. Based on the available data from mechanistic, animal and epidemiological studies including meta-analyses, the weight of evidence points towards the contribution of EDCs to the development of obesity, associated disorders and obesity-related adipose tissue dysfunction by (1) impacting adipogenesis; (2) modulating epigenetic pathways during development, enhancing susceptibility to obesity; (3) influencing neuroendocrine signals responsible for appetite and satiety; (4) promoting a proinflammatory milieu in adipose tissue and inducing a state of chronic subclinical inflammation; (5) dysregulating gut microbiome and immune homeostasis; and (6) inducing dysfunction in thermogenic adipose tissue. Critical periods of exposure to obesogenic EDCs are the prenatal, neonatal, pubertal and reproductive periods. Interestingly, EDCs even at low doses may promote epigenetic transgenerational inheritance of adult obesity in subsequent generations. The aim of this review is to summarize the available evidence on the role of obesogenic EDCs, specifically BPA and phthalate plasticizers, in the development of obesity, taking into account in vitro, animal and epidemiologic studies; discuss mechanisms linking EDCs to obesity; analyze the effects of EDCs on obesity in critical chronic periods of exposure; and present interesting perspectives, challenges and preventive measures in this research area.

Gut Microbiota and Its Role in the Brain-Gut-Kidney Axis in Hypertension

PURPOSE OF REVIEW

The role of the gut microbiota in modulating blood pressure is increasingly being recognized, currently. The purpose of this review is to summarize recent findings about the mechanisms involved in hypertension with regard to the phenomenon of "gut dysbiosis."

RECENT FINDINGS

Gut dysbiosis, i.e., the imbalance between the gut microbiota and the host, is characterized by a disruption of the tight junction proteins, such as occludins, claudins, and JAMs (junctional adhesion molecules), resulting in increased gut permeability or the so called "leaky gut." Due to the influence of genetic as well as environmental factors, various metabolites produced by the gut microbiota, such as indole and p-cresol, are increased. Thereby, uremic toxins, such as indoxyl sulfates and p-cresol sulfates, accumulate in the blood and the urine, causing damage in the podocytes and the tubular cells. In addition, immunological mechanisms are implicated as well. In particular, a switch from M2 macrophages to M1 macrophages, which produce pro-inflammatory cytokines, occurs. Moreover, a higher level of Th17 cells, releasing large amounts of interleukin-17 (IL-17), has been reported, when a diet rich in salt is consumed. Therefore, apart from the aggravation of uremic toxins, which may account for direct harmful effects on the kidney, there is inflammation not only in the gut, but in the kidneys as well. This crosstalk between the gut and the kidney is suggested to play a crucial role in hypertension. Notably, the brain is also implicated, with an increasing sympathetic output. The brain-gut-kidney axis seems to be deeply involved in the development of hypertension and chronic kidney disease (CKD). The notion that, by modulating the gut microbiota, we could regulate blood pressure is strongly supported by the current evidence. A healthy diet, low in animal protein and fat, and low in salt, together with the utilization of probiotics, prebiotics, synbiotics, or postbiotics, may contribute to our fight against hypertension.

Immunotherapy in Head and Neck Cancer: Where Do We Stand?

PURPOSEOF REVIEW

Head and neck cancer (HNC) comprises a group of malignancies, amongst which squamous cell carcinoma accounts for more than 90% of the cases. HNC has been related to tobacco use, alcohol consumption, human papillomavirus, Epstein-Barr virus, air pollution, and previous local radiotherapy. HNC has been associated with substantial morbidity and mortality. This review aims to summarize the recent findings regarding immunotherapy in HNC.

RECENT FINDINGS

The recent introduction of immunotherapy, with the use of programmed death 1 (PD-1) inhibitors pembrolizumab and nivolumab, which have been FDA approved for the treatment of metastatic or recurrent head and neck squamous cell carcinoma, has changed the field in metastatic or recurrent disease. There are many ongoing trials regarding the use of novel immunotherapeutic agents, such as durvalumab, atezolizumab, avelumab, tremelimumab, and monalizumab. In this review, we focus on the therapeutic potential of novel immunotherapy treatment modalities, such as combinations of newer immune-checkpoint inhibitors; the use of tumor vaccines such as human papillomavirus-targeted vaccines; the potential use of oncolytic viruses; as well as the latest advances regarding adoptive cellular immunotherapy. As novel treatment options are still emerging, a more personalized approach to metastatic or recurrent HNC therapy should be followed. Moreover, the role of the microbiome in immunotherapy, the limitations of immunotherapy, and the various diagnostic, prognostic, and predictive biomarkers based on genetics and the tumor microenvironment are synopsized.

Laboratory Findings and Biomarkers in Long COVID: What Do We Know So Far? Insights into Epidemiology, Pathogenesis, Therapeutic Perspectives and Challenges

Long COVID (LC) encompasses a constellation of long-term symptoms experienced by at least 10% of people after the initial SARS-CoV-2 infection, and so far it has affected about 65 million people. The etiology of LC remains unclear; however, many pathophysiological pathways may be involved, including viral persistence; a chronic, low-grade inflammatory response; immune dysregulation and a defective immune response; the reactivation of latent viruses; autoimmunity; persistent endothelial dysfunction and coagulopathy; gut dysbiosis; hormonal and metabolic dysregulation; mitochondrial dysfunction; and autonomic nervous system dysfunction. There are no specific tests for the diagnosis of LC, and clinical features including laboratory findings and biomarkers may not specifically relate to LC. Therefore, it is of paramount importance to develop and validate biomarkers that can be employed for the prediction, diagnosis and prognosis of LC and its therapeutic response, although this effort may be hampered by challenges pertaining to the non-specific nature of the majority of clinical manifestations in the LC spectrum, small sample sizes of relevant studies and other methodological issues. Promising candidate biomarkers that are found in some patients are markers of systemic inflammation, including acute phase proteins, cytokines and chemokines; biomarkers reflecting SARS-CoV-2 persistence, the reactivation of herpesviruses and immune dysregulation; biomarkers of endotheliopathy, coagulation and fibrinolysis; microbiota alterations; diverse proteins and metabolites; hormonal and metabolic biomarkers; and cerebrospinal fluid biomarkers. At present, there are only two reviews summarizing relevant biomarkers; however, they do not cover the entire umbrella of current biomarkers, their link to etiopathogenetic mechanisms or the diagnostic work-up in a comprehensive manner. Herein, we aim to appraise and synopsize the available evidence on the typical laboratory manifestations and candidate biomarkers of LC, their classification based on pathogenetic mechanisms and the main LC symptomatology in the frame of the epidemiological and clinical aspects of the syndrome and furthermore assess limitations and challenges as well as potential implications in candidate therapeutic interventions.

Diagnostic and Prognostic Value of Serum Omentin-1 in Sepsis: A Prospective Study in Critically Ill Patients

Background and Objectives: Omentin-1, also known as intelectin-1, is a novel adipokine with anti-inflammatory activities implicated in inflammatory diseases and sepsis. We aimed to explore serum omentin-1 and its kinetics in critically ill patients early in sepsis and its association with severity and prognosis. Materials and Methods: Serum omentin-1 was determined in 102 critically ill patients with sepsis during the first 48 h from sepsis onset and 1 week later, and in 102 age- and gender-matched healthy controls. The outcome of sepsis at 28 days after enrollment was recorded. Results: Serum omentin-1 at enrollment was significantly higher in patients compared to controls (763.3 ± 249.3 vs. 451.7 ± 122.3 μg/L, p < 0.001) and it further increased 1 week after (950.6 ± 215.5 vs. 763.3 ± 249.3 μg/L, p < 0.001). Patients with septic shock (n = 42) had higher omentin-1 compared to those with sepsis (n = 60) at enrollment (877.9 ± 241.2 vs. 683.1 ± 223.7 μg/L, p < 0.001) and 1 week after (1020.4 ± 224.7 vs. 901.7 ± 196.3 μg/L, p = 0.007). Furthermore, nonsurvivors (n = 30) had higher omentin-1 at sepsis onset (952.1 ± 248.2 vs. 684.6 ± 204.7 μg/L, p < 0.001) and 1 week after (1051.8 ± 242 vs. 908.4 ± 189.8 μg/L, p < 0.01). Patients with sepsis and survivors presented higher kinetics than those with septic shock and nonsurvivors (Δ(omentin-1)% 39.8 ± 35.9% vs. 20.2 ± 23.3%, p = 0.01, and 39.4 ± 34.3% vs. 13.3 ± 18.1%, p < 0.001, respectively). Higher omentin-1 at sepsis onset and 1 week after was an independent predictor of 28-day mortality (HR 2.26, 95% C.I. 1.21-4.19, p = 0.01 and HR: 2.15, 95% C.I. 1.43-3.22, p < 0.001, respectively). Finally, omentin-1 was significantly correlated with the severity scores, the white blood cells, coagulation biomarkers, and CRP, but not procalcitonin and other inflammatory biomarkers. Conclusions: Serum omentin-1 is increased in sepsis, while higher levels and lower kinetics during the first week of sepsis are associated with the severity and 28-day mortality of sepsis. Omentin-1 may be a promising biomarker of sepsis. However, more studies are needed to explore its role in sepsis.

The Role of Next-Generation Probiotics in Obesity and Obesity-Associated Disorders: Current Knowledge and Future Perspectives

Obesity and obesity-associated disorders pose a major public health issue worldwide. Apart from conventional weight loss drugs, next-generation probiotics (NGPs) seem to be very promising as potential preventive and therapeutic agents against obesity. Candidate NGPs such as Akkermansia muciniphila, Faecalibacterium prausnitzii, Anaerobutyricum hallii, Bacteroides uniformis, Bacteroides coprocola, Parabacteroides distasonis, Parabacteroides goldsteinii, Hafnia alvei, Odoribacter laneus and Christensenella minuta have shown promise in preclinical models of obesity and obesity-associated disorders. Proposed mechanisms include the modulation of gut flora and amelioration of intestinal dysbiosis, improvement of intestinal barrier function, reduction in chronic low-grade inflammation and modulation of gut peptide secretion. Akkermansia muciniphila and Hafnia alvei have already been administered in overweight/obese patients with encouraging results. However, safety issues and strict regulations should be constantly implemented and updated. In this review, we aim to explore (1) current knowledge regarding NGPs; (2) their utility in obesity and obesity-associated disorders; (3) their safety profile; and (4) their therapeutic potential in individuals with overweight/obesity. More large-scale, multicentric and longitudinal studies are mandatory to explore their preventive and therapeutic potential against obesity and its related disorders.

The Role of the Respiratory Microbiome in the Pathogenesis of Aspiration Pneumonia: Implications for Diagnosis and Potential Therapeutic Choices

Although the lungs were considered to be sterile until recently, the advent of molecular biology techniques, such as polymerase chain reaction, 16 S rRNA sequencing and metagenomics has led to our expanding knowledge of the lung microbiome. These methods may be particularly useful for the identification of the causative agent(s) in cases of aspiration pneumonia, in which there is usually prior administration of antibiotics. The most common empirical treatment of aspiration pneumonia is the administration of broad-spectrum antibiotics; however, this may result in negative cultures from specimens taken from the respiratory tract. Therefore, in such cases, polymerase chain reaction or metagenomic next-generation sequencing may be life-saving. Moreover, these modern molecular methods may assist with antimicrobial stewardship. Based upon factors such as age, altered mental consciousness and recent hospitalization, there is a shift towards the predominance of aerobes, especially Gram-negative bacteria, over anaerobes in aspiration pneumonia. Thus, the therapeutic choices should be expanded to cover multi-drug resistant Gram-negative bacteria in selected cases of aspiration pneumonia.

Severe eosinophilic granulomatosis with polyangiitis responding to a combination of rituximab and mepolizumab

Eosinophilic granulomatosis with polyangiitis (EGPA), formerly known as Churg-Strauss Syndrome, is a multisystem antineutrophil cytoplasmic antibody (ANCA) positive vasculitis, characterized by the presence of chronic rhinosinusitis, asthma and prominent peripheral blood eosinophilia. Although the most commonly involved organ is the lung, followed by the skin, EGPA can affect any organ system. Herein, we present the complicated case of an 18-year-old male patient with severe life-threatening EGPA, with central nervous system, cardiac and gasterointestinal involvement, which was resistant to initial treatment with glucocorticoids and cyclophosphamide. The patient responded well, achieving complete remission after the addition of rituximab and mepolizumab to glucocorticoids and cyclophosphamide.

Lower circulating omentin-1 is independently linked to subclinical hypothyroidism reflecting cardiometabolic risk: an observational case-control and interventional, longitudinal study

BACKGROUND

Omentin-1, a newly discovered adipokine, is implicated in the modulation of the adipose phenotype, ameliorating systemic metabolism and exhibiting anti-atherogenic, anti-oxidative, cardioprotective, anti-inflammatory and insulin-sensitizing properties. Our goal was to explore circulating omentin-1 in subclinical hypothyroidism (SH) and determine its correlations with cardiometabolic risk factors.

METHODS

In a large case-control and interventional longitudinal study, serum omentin-1, metabolic and lipid parameters, inflammatory biomarkers, classic adipocytokines and cardiovascular risk factors were assessed in 120 consecutive patients with SH and 120 healthy controls matched on age, gender and date of blood draw. Sixteen patients with SH were administered L-T4 and, after six months, circulating omentin-1 and other biomarkers were determined.

RESULTS

SH subjects presented significantly decreased circulating omentin-1 than control individuals (P<0.001). In all study participants, omentin-1 was negatively correlated with TSH, anti-thyroid antibodies, HOMA-IR, C-peptide, lipid and inflammatory biomarkers, adipokines and cardiovascular risk factors, including Framingham score and apolipoprotein B. Omentin-1 was positively associated with adiponectin and HDL-C. Circulating omentin-1 was independently associated with SH occurrence, above and beyond clinical and cardiometabolic factors (P=0.04). TSH was a negative independent predictor of serum omentin-1 levels (P<0.001). L-T4 treatment did not alter considerably the lower omentin-1 levels in treated SH patients (P=0.07).

CONCLUSIONS

Omentin-1 may be a useful non-invasive biomarker reflecting cardiometabolic risk as well as a promising therapeutic target. More mechanistic and larger prospective studies shedding light on the pathogenetic role of omentin-1 in SH are required to confirm these findings.

Therapeutic Potential of GLP-2 Analogs in Gastrointestinal Disorders: Current Knowledge, Nutritional Aspects, and Future Perspectives

PURPOSE OF REVIEW

Although Glucagon-like peptide (GLP)-1 receptor agonists have been used for almost two decades in the treatment of diabetes mellitus type 2 and, lately, in obesity, recent years have seen an increasing interest in the pharmacological agonism of other proglucagon-derived peptides, including GLP-2. Herein, we aimed to review the available evidence on the effects of GLP-2 agonism from animal and clinical studies. Furthermore, we summarize the current clinical applications of GLP-2 agonists among patients with intestinal failure associated with short bowel syndrome (SBS-IF) as well as potential future expansion of their indications to other intestinal disorders.

RECENT FINDINGS

Evidence from preclinical studies has highlighted the cellular trophic and functional beneficial actions of GLP-2 on small intestinal and colonic mucosa. Subsequently, pharmacologic agonism of GLP-2 has gathered interest for the treatment of patients with conditions pertaining to the loss of intestinal anatomical and/or functional integrity to a degree requiring parenteral support, collectively referred to as intestinal failure. GLP-2 analogs positively influence nutrient absorption in animal models and humans, although continued therapy is likely needed for sustained effects. The degradation-resistant GLP-2-analog teduglutide has received approval for the treatment of SBS-IF, in which it may decisively reduce patient dependency on parenteral support and improve quality of life. Another two longer-acting analogs, glepaglutide and apraglutide, are currently undergoing phase III clinical trials. The use of GLP-2 analogs is effective in the management of SBS-IF and may show promise in the treatment of other severe gastrointestinal disorders associated with loss of effective intestinal resorptive surface area.

Breakthrough infections after COVID-19 vaccination: Insights, perspectives and challenges

Vaccination programs against SARS-CoV-2 constitute the mainstay of public health interventions against the global COVID-19 pandemic. Currently available vaccines have shown 90% or better rates of protection against severe disease and mortality. Barely a year after vaccines became available, the Omicron variant and its unprecedented speed of transmission has posed a new challenge. Overall, Omicron presents increased immune escape, transmissibility, and decreased pathogenicity. Vaccines do not offer a full protection against SARS-CoV-2 acquisition, since "breakthrough" infections may occur in fully vaccinated individuals, who may in turn spread the virus to others. Breakthrough infections may be causally related to the viral profile (viral variant and load, incubation period, transmissibility, pathogenicity, immune evasion), immunity characteristics (mucosal versus systemic immunity, duration of immunity, etc.), host determinants (age, comorbidities, immune status, immunosuppressive drugs) and vaccination properties (platform, antigen dose, dose number, dose interval, route of administration). Determining the rate of breakthrough infections may be challenging and necessitates the conduction of population-based studies regarding vaccine effectiveness as well as neutralizing antibody testing, a surrogate of immune protection. In this review, we analyze the causes of breakthrough infections, their clinical consequences (severity of infection and transmission), methods of determining their incidence as well as challenges and perspectives. Long COVID as well as multi-inflammatory syndrome in adolescents may be significantly reduced in breakthrough infections. The need for universal pancoranavirus vaccines that would aim at protecting against a plethora of SARS-CoV-2 variants as well as emerging variants is discussed. Finally, novel vaccine strategies, such as nasal vaccines, may confer robust mucosal and systemic protection, reducing efficiently transmission.

Potential implications of lipid nanoparticles in the pathogenesis of myocarditis associated with the use of mRNA vaccines against SARS-CoV-2

Although mRNA-based vaccines BNT162b2 and mRNA-1273 exhibit a remarkable efficacy and effectiveness in preventing particularly severe Covid-19 with an overall favorable adverse event profile, their use has been associated with rare cases of acute myocarditis. These occur most commonly after the second dose, with the highest incidence among young male recipients. This complication has not been frequently observed among adenoviral vector vaccine receivers, and its clinical, laboratory and imaging features resemble those of other common causes of acute myocarditis. The pathogenesis of mRNA-vaccine associated myocarditis has not yet been elucidated, although a number of mechanisms have been proposed, typically implicating the administered S-protein mRNA and likely mediated through an autoimmune mechanism. Nonetheless, other mechanisms may be implicated given the fact that myocarditis cases are very rarely observed among recipients of non mRNA vaccines. The recent observation of a similar adverse event in a recipient of the non-mRNA, peptide-based NVX-CoV2373 in the frame of a phase III clinical trial with 7020 participants in the active treatment arm raises the question whether the lipid nanoparticle sheath, which is a common structural component of these platforms could be implicated in the pathogenesis of vaccine-induced myocarditis.

Could inhaled corticosteroids be the game changers in the prevention of severe COVID-19? A review of current evidence

As the coronavirus 2019 disease (COVID-19) pandemic is going through its second year, the world is counting more than 4.9 million lives lost. Many repurposed immunomodulatory drugs have been tried and failed to treat COVID-19. The only successful treatments that improve survival are systemic corticosteroids and tocilizumab, by targeting the systemic inflammatory cascade. An intriguing observation that patients with chronic respiratory disease seem to be less prone to COVID-19 gave ground to the hypothesis that inhaled corticosteroids (ICS) may protect them from SARS-CoV-2 infection. In this review, we summarize current evidence regarding the therapeutic role of inhaled and systemic corticosteroids in COVID-19, and we present experimental data on the potential actions of ICS against SARS-CoV-2 infection. We also discuss safety issues as well as therapeutic considerations and clinical implications of the use of ICS in COVID-19. Four randomized controlled trials (RCT) with more than 3,000 participants suggest that ICS may lead to earlier clinical improvement and lower rate of hospitalization in patients with mild COVID-19, while 9 ongoing RCTs are anticipated to provide more evidence for the use of ICS in COVID-19. Recent evidence has shown promise that ICS could provide tangible benefits to patients suffering from COVID-19.

Diabetes type 1: Can it be treated as an autoimmune disorder?

Type 1 Diabetes Mellitus (T1DM) is characterized by progressive autoimmune-mediated destruction of the pancreatic beta-cells leading to insulin deficiency and hyperglycemia. It is associated with significant treatment burden and necessitates life-long insulin therapy. The role of immunotherapy in the prevention and management of T1DM is an evolving area of interest which has the potential to alter the natural history of this disease.In this review, we give insight into recent clinical trials related to the use of immunotherapeutic approaches for T1DM, such as proinflammatory cytokine inhibition, cell-depletion and cell-therapy approaches, autoantigen-specific treatments and stem cell therapies. We highlight the timing of intervention, aspects of therapy including adverse effects and the emergence of a novel lymphocyte crucial in T1DM autoimmunity. We also discuss the role of cardiac autoimmunity and its link to excess CVD risk in T1DM.We conclude that significant advances have been made in development of immunotherapeutic targets and agents for the treatment and prevention of T1DM. These immune-based therapies promise preservation of beta-cells and decreasing insulin dependency. In their current state, immunotherapeutic approaches cannot yet halt the progression from a preclinical state to overt T1DM nor can they replace standard insulin therapy in existing T1DM. It remains to be seen whether immunotherapy will ultimately play a key role in the prevention of progression to overt T1DM and whether it may find a place in our therapeutic armamentarium to improve clinical outcomes and quality of life in established T1DM.

Vaccine induced thrombotic thrombocytopenia: The shady chapter of a success story

The recognition of the rare but serious and potentially lethal complication of vaccine induced thrombotic thrombocytopenia (VITT) raised concerns regarding the safety of COVID-19 vaccines and led to the reconsideration of vaccination strategies in many countries. Following the description of VITT among recipients of adenoviral vector ChAdOx1 vaccine, a review of similar cases after Ad26.COV2·S vaccination gave rise to the question whether this entity may constitute a potential class effect of all adenoviral vector vaccines. Most cases are females, typically younger than 60 years who present shortly (range: 5-30 days) following vaccination with thrombocytopenia and thrombotic manifestations, occasionally in multiple sites. Following initial incertitude, concrete recommendations to guide the diagnosis (clinical suspicion, initial laboratory screening, PF4-polyanion-antibody ELISA) and management of VITT (non-heparin anticoagulants, corticosteroids, intravenous immunoglobulin) have been issued. The mechanisms behind this rare syndrome are currently a subject of active research and include the following: 1) production of PF4-polyanion autoantibodies; 2) adenoviral vector entry in megacaryocytes and subsequent expression of spike protein on platelet surface; 3) direct platelet and endothelial cell binding and activation by the adenoviral vector; 4) activation of endothelial and inflammatory cells by the PF4-polyanion autoantibodies; 5) the presence of an inflammatory co-signal; and 6) the abundance of circulating soluble spike protein variants following vaccination. Apart from the analysis of potential underlying mechanisms, this review aims to synopsize the clinical and epidemiologic features of VITT, to present the current evidence-based recommendations on diagnostic and therapeutic work-up of VITT and to discuss new dilemmas and perspectives that emerged after the description of this entity.

Anti-viral treatment for SARS-CoV-2 infection: A race against time amidst the ongoing pandemic

Remdesivir (GS-5734), a drug initially developed to treat hepatitis C and Ebola virus disease, was the first approved treatment for severe coronavirus disease 2019 (COVID-19). However, apart from remdesivir, there is a paucity of other specific anti-viral agents against SARS-CoV-2 infection. In 2017, researchers had documented the anti-coronavirus potential of remdesivir in animal models. At the same time, trials performed during two Ebola outbreaks in Africa showed that the drug was safe. Although vaccines against SARS-CoV-2 infection have emerged at an enormously high speed, equivalent results from efforts towards the development of anti-viral drugs, which could have played a truly life-saving role in the current stage of the pandemic, have been stagnating. In this review, we will focus on the current treatment options for COVID-19 which mainly consist of repurposed agents or treatments conferring passive immunity (convalescent plasma or monoclonal antibodies). Additionally, potential specific anti-viral therapies under development will be reviewed, such as the decoy miniprotein CTC-445.2d, protease inhibitors, mainly against the Main protein Mpro, nucleoside analogs, such as molnupiravir and compounds blocking the replication transcription complex proteins, such as zotatifin and plitidepsin. These anti-viral agents seem to be very promising but still require meticulous clinical trial testing in order to establish their efficacy and safety. The continuous emergence of viral variants may pose a real challenge to the scientific community towards that end. In this context, the advent of nanobodies together with the potential administration of a combination of anti-viral drugs could serve as useful tools in the armamentarium against COVID-19.

Co-existence of Follicular Lymphoma in the Lymph Node with High-grade B Cell Lymphoma in the Bone Marrow of a Patient with Spontaneous Tumor Lysis Syndrome

A significant percentage of B-cell lymphomas are characterized by bone marrow involvement (BMI) at diagnosis. In most cases, there is a concordance between the type of lymphoma present in the lymph node and the lymphoma present in the bone marrow. Herein, we presented a sixty-seven years old female patient, who was diagnosed with High-Grade B-cell Lymphoma (HGBL) in the bone marrow, while simultaneously, in the peripheral lymph node, the presence of Follicular Lymphoma (FL) was noted. The patient was presented to the hospital with spontaneous tumor lysis syndrome, a finding compatible with the aggressive course of the HGBL. To our knowledge, this is the first case of the co-existence of HGBL in the bone marrow and FL in a lymph node, which might be attributed to merely a coincidence or to the transformation of the cells in the preferable milieu of the bone marrow.

Cardiac MRI in autoimmune diseases: where are we now?

Cardiovascular magnetic resonance imaging (CMR) allows the early diagnosis of various cardiovascular pathophysiologic phenomena in autoimmune diseases. Preliminary studies suggest that CMR holds a promising role in initiating the necessary changes in anti-rheumatic and cardiac treatment among patients with autoimmune diseases and cardiovascular diseases (CVD). It is widely known that the presence of late gadolinium enhancement (LGE) has been related to worse cardiovascular prognosis. CMR has been documented to be the most valuable tool for diagnosis and risk prediction of cardiac involvement in a sarcoidosis population, while in SLE, the gap between clinical and autopsy diagnosis of myocardial disease could be narrowed with the implementation of CMR. In different connective tissue diseases, including SLE, LGE has been demonstrated to be present, early after the initial diagnosis of SLE. Considering that CMR including LGE identifies more patients with silent myocardial disease in SLE and other connective tissue diseases than echocardiography, CMR should be the preferred imaging modality, especially in the era of modern techniques with a broader availability and expertise. In this review, we summarize the major indications, advantages and limitations of the use of CMR among patients with autoimmune disorders.

Diabetes Mellitus and SARS-CoV-2 Infection: Pathophysiologic Mechanisms and Implications in Management

INTRODUCTION

Currently, diabetes mellitus (DM), as well as coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), are major public health issues worldwide.

BACKGROUND

It has been suggested that patients with DM are more vulnerable to SARS-CoV-2 infection and suffer from more severe forms of the disease.

METHODS

A literature search was performed using PubMed, Scopus, and Google search engines.

RESULTS

Angiotensin-converting enzyme-2 (ACE2) is the major receptor of SARS-CoV-2 in the human host. The differential expression of ACE2 in the lungs of patients with DM makes them more susceptible to COVID-19. Additionally, acute or chronic hyperglycemia renders individuals in an immune-suppressive state, with impaired innate and adaptive immunity function, also contributing to the severity of COVID-19 infection among patients with DM. Other factors contributing to a more severe course of COVID-19 include the coexistence of obesity in T2DM, the endothelial inflammation induced by the SARS-CoV-2 infection, which aggravates the endothelial dysfunction observed in both T1DM and T2DM, and the hypercoagulability presented in COVID-19 infection that increases the thrombotic tendency in DM.

CONCLUSION

This review summarizes the pathophysiologic mechanisms underlying the coexistence of both pandemics as well as the current recommendations and future perspectives regarding the optimal treatment of inpatients and outpatients with DM in the era of SARS-CoV-2 infection. Notably, the currently recommended drugs for the treatment of severe COVID-19, dexamethasone and remdesivir, may cause hyperglycemia, an adverse effect that physicians should bear in mind when caring for patients with DM and COVID-19.

Microbiome and hypertension: where are we now?

BACKGROUND

Hypertension is the leading risk factor for cardiovascular disease and accounts for approximately 9.4 million deaths globally every year. Hypertension is a complex entity, which is influenced by genetic and environmental factors, such as physical inactivity, obesity, alcohol consumption, tobacco use, stress, diet and why not the microbiome.

METHODS

We searched PubMed using the words 'microbiome', 'microbiota' and 'hypertension' until December 2018. We found information regarding the role of the brain-gut--bone marrow axis, the brain-gut--kidney axis, the high-salt diet, short-chain fatty acids (SCFAs), neurotransitters, such as serotonin, dopamine and norepinephrine, nitric oxide, endothelin and steroids in modulating gut microbiota and in contributing to the pathogenesis of hypertension. The brain--gut--bone marrow axis refers to the hypothesis that hematopoietic stem cells might migrate to the brain or to the gut, and thus, contribute to local inflammation and several immune responses. This migration may further enhance the sympathetic activity and contribute to blood pressure elevation. On the other hand, SCFAs, such as acetate and butyrate, have been shown to exert anti-inflammatory effects on myeloid and intestinal epithelial cells. Also, researchers have noted diminution in microbial richness and diversity in hypertensive patients as well as marked differences in circulating inflammatory cells in hypertensive patients, when compared with controls. In addition, activation of renal sympathetic nerve activity might directly influence renal physiology, by altering body fluid balance and plasma metabolite secretion and retention. These events culminate in the development of chronic kidney disease and hypertension.

CONCLUSION

There is a long way ahead regarding the role of gut microbiota in the pathogenesis and as an adjunctive treatment of hypertension. Treatment of dysbiosis could be a useful therapeutic approach to add to traditional antihypertensive therapy. Manipulating gut microbiota using prebiotics and probiotics might prove a valuable tool to traditional antihypertensives.

Clostridioides difficile infection in a patient with immunoglobulin A vasculitis: a triggering factor or a rare complication of the disease? A case-based review

IgA vasculitis, formerly known as Henoch-Schonlein purpura (HSP), is the most common form of systemic vasculitis in children and is characterized by inflammation of the small vessels with typical deposition of IgA immune complexes. It is a leukocytoclastic type of vasculitis and is characterized by a tetrad of clinical manifestations: non-thrombocytopenia or coagulopathy-induced palpable purpura, arthritis, or arthralgia, gastrointestinal, and renal involvement. The exact cause of IgA vasculitis is not known yet, although infections, vaccinations and insect bites have been implicated in the appearance of the disease. The main risk factors for Clostridioides difficile infection (CDI) are previous CDI, age > 65 years old, pharmacologic agents (antibiotics, PPIs, histamine-2 receptor antagonists, glucocorticoids, and chemotherapy), prior hospitalization, the presence of co-morbidities, especially inflammatory bowel diseases and chronic kidney disease (CKD) and immunosuppression. Oral vancomycin or fidaxomicin are the gold standard of the therapy, with metronidazole being an alternative choice. The purpose of this study was to describe a case of IgA vasculitis and Clostridioides difficile infection to see whether there is any association between the two distinct clinical entities. Herein, we describe a 17-year old patient with IgA vasculitis and bloody diarrhea due to Clostridioides difficile infection and we discuss the co-existence of these two pathological conditions. The patient presented to the hospital with diffuse abdominal pain, nausea, vomiting, and two episodes of bloody diarrhea. Stools tested positive for Clostridioides difficile toxins, while he remained afebrile with hs-CRP = 1.5 mg/dL (normal range < 0.5 mg/dL). Direct immunofluorescence from the extremities' purplish eruption showed leukocytoclastic vasculitis with IgA deposition. Whether co-existence of the two above-mentioned distinct clinical entities is just a co-incidence or CDI is a triggering factor for IgA vasculitis remains to be elucidated in future large-scale studies.

Silimarin and Cancer

BACKGROUND

Silimarin is the dry mixture of a whole family of natural substances, extracted after the addition of ethanol, methanol, and acetone. Silimarin consists mainly of silibin A and silibin B, as well as other less important compounds.

METHODS

Silimarin has been demonstrated to "inhibit cell proliferation and to induce apoptosis, while also having anti-angiogenic properties." The induction of apoptosis in cancer cells has been mediated by the involvement of ER stress.

RESULTS

Silibinin has the potential to operate as a STAT3-targeted inhibitor as well as an inhibitor of the upregulation of the immune checkpoint regulator PD-L1 and also EMT regulators, thus being a promising adjuvant in NSCLC. It has also been documented to suppress cancer cells be means of down- regulating actin cytoskeleton and PI3K / Akt molecular pathways. Several studies have demonstrated that silibinin exerts its protective potential partly through interacting with the tumor suppressor gene p53.

CONCLUSIONS

It is noteworthy that research has been carried out on the enhancement of silimarin's bioavailability, especially by the preparation of specific nanoformulas, and its probable additional use together with the chemotherapeutic regimens in the near future.

Metformin and gut microbiota: their interactions and their impact on diabetes

The ratio of human to bacterial cells in the human body (microbiota) is around 1:1. As a result of co-evolution of the host mucosal immune system and the microbiota, both have developed multiple mechanisms to maintain homeostasis. However, dissociations between the composition of the gut microbiota and the human host may play a crucial role in the development of type 2 diabetes. Metformin, the most frequently administered medication to treat patients with type 2 diabetes, has only recently been suggested to alter gut microbiota composition through the increase in mucin-degrading Akkermansia muciniphila, as well as several SCFA-producing (short-chain fatty acid) microbiota. The gut microbiota of participants on metformin has exerted alterations in gut metabolomics with increased ability to produce butyrate and propionate, substances involved in glucose homeostasis. Thus, metformin appears to affect the microbiome, and an individual's metformin tolerance or intolerance may be influenced by their microbiome. In this review, we will focus on the effects of metformin in gut microbiota among patients with T2DM.

An HHV-8 Positive HIV Negative Multicentric Castleman's Disease, who Responded well to Rituximab Alone

BACKGROUND

Multicentric Castleman Disease (MCD) presents with enlarged lymph nodes in multiple regions and systemic inflammatory symptoms, due to the dysregulation of cytokines, most commonly interleukin-6 (IL-6). Human herpes virus-8 (HHV-8) is strongly related to MCD (HHV-8-associated MCD) and is being implicated in cytokine dysregulation in patients, the majority of whom are HIV positive or immunosuppressed. Preferred treatment of HHV-8- associated MCD depends on the presence or not of concurrent Kaposi sarcoma and on whether the patient has life-threatening organ failure or poor performance status thought to be related to HHV- 8-associated MCD.

CASE PRESENTATION

Herein, we describe a female patient with HHV-8 positive, HIV negative MCD, who responded well to the administration of rituximab once weekly for four weeks alone for three cycles.

CONCLUSION

HHV-8 positive, HIV negative MCD treatment modalities are only anecdotal due to the rarity of this form of MCD. Administration of rituximab alone seems to be beneficial among patients with good performance status and the absence of life-threatening organ failure in cases of HHV-8 positive, HIV negative MCD.

Microbiota and cancer: an update

The number of microbes in the human intestine is approximately 1 × 10¹⁴, while the number of eukaryotic cells in the human body is around 1 × 10¹³. As a result of co-evolution of the host mucosal immune system and the microbiota, both have developed multiple mechanisms to maintain homeostasis. Nevertheless, when these mechanisms are disturbed by pathogenic bacteria, which invade this fragile environment, the immune system responds to the microbiota and may support tumour growth in the intestine. Data advocate that the microbiota and its interactions with the host could also be implicated in carcinogenesis in other organs. It is nowadays suggested that developing methods to selectively manipulate components of the microbiota and ultimately target tumorigenesis represents a complex but exciting challenge. In this review, the main pathogenetic mechanisms of the interplay between the microbiome and the innate system, which may be implicated in tumorigenesis are discussed. Also, the importance of the gut microbiota regarding efficacy and toxicity of current chemotherapeutic agents, as well as the direct antitumor properties of the microbiota, will be reviewed.

Chronic Kidney Disease and Cardiovascular Disease: Is there Any Relationship?

INTRODUCTION

Chronic Kidney Disease is a growing health burden world wide. Traditional and mutual risk factors between CVD and CKD are age, hypertension, diabetes mellitus, dyslipidemia, tobacco use, family history and male gender. In this review, we will focus on whether or not early CKD is an important risk factor for the presence, severity and progression of CVD. Specifically, we will examine both traditional and novel risk factors of both CKD and CVD and how they relate to each other.

CONCLUSION

We will also assess if early treatment of CKD, intensive compared to standard, has an important effect on the halt of the development of CKD as well as CVD. Insights into the pathogenesis and early recognition of CKD as well as the importance of novel kidney biomarkers will be pointed out. Also, common pathogenetic mechanisms between CKD and CVD will be discussed.

Microbiome and diabetes: Where are we now?

Alterations in the diversity or structure of gut microbiota known as dysbiosis, may affect metabolic activities, resulting in metabolic disorders, such as obesity and diabetes. The development of more sophisticated methods, such as metagenomics sequencing, PCR-denaturing gradient gel electrophoresis, microarrays and fluorescence in situ hybridization, has expanded our knowledge on gut microbiome. Dysbiosis has been related to increased plasma concentrations of gut microbiota-derived lipopolysaccharide (LPS), which triggers the production of a variety of cytokines and the recruitment of inflammatory cells. Metabolomics have demonstrated that butyrate and propionate suppress weight gain in mice with high fat diet-induced obesity, and acetate has been proven to reduce food intake in healthy mice. The role of prebiotics, probiotics, genetically modified bacteria and fecal microbiota transplantation, as potential therapeutic challenges for type 2 diabetes will be discussed in this review.

ANGPTL3 Inhibitors - Their Role in Cardiovascular Disease Through Regulation of Lipid Metabolism

Elevated plasma lipid levels are linked to atherosclerosis, a hallmark for coronary artery disease (CAD), documented by animal studies as well as angiographic and clinical studies. The ability to treat hyperlipidemia through lifestyle changes and lipid-lowering agents has been related to the slow progression of atherosclerosis and decreased incidence of major coronary events. Angiopoietin-like proteins (ANGPTLs) are a family of secreted glycoproteins expressed in the liver that share common domain characteristics with angiopoietins, the main regulators of angiogenesis. Although ANGPTLs cannot bind the angiopoietin receptors expressed on endothelial cells, 2 ANGPTL family members (ANGPTL3 and ANGPTL4) have clinical importance because of their unambiguous effects on lipoprotein metabolism in mice and humans. The regulation of plasma lipid levels by ANGPTL3 is controlled via affecting lipoprotein lipase and endothelial lipase-mediated hydrolysis of triglycerides (TGs) and phospholipids. ANGPTL 3, along with the other 2 members, 4 and 8, is a key to balancing the distribution of circulating TGs between white adipose tissue (WAT) and oxidative tissues. Thus, ongoing trials with newly discovered medications in the form of monoclonal antibodies or antisense oligonucleotides with novel targets are under analysis and may represent a fresh frontier in the treatment of hyperlipidemia and CAD.

Testicular abscesses due to Brucella melitensis

Brucella may cause testicular masses, which may be confused with a testicular tumour. We present the case of a man with fever and oedema in the scrotum. Ultrasound and colour Doppler ultrasound with a 6 to 15 MHz high-frequency linear-array transducer was performed, revealing bilateral scrotal wall oedema, heterogeneous echo texture and slightly increased vascularization of the right testis, with hypoechoic lesions characterized by hypervascular margins and no flow within them. These findings were compatible with testicular abscesses. Three blood cultures grew Brucella melitensis, so the patient received treatment with doxycycline and rifampin for 8 weeks, which resulted in disappearance of the testicular abscesses.

Inverse Relationship between Adherence to the Mediterranean Diet and Serum Cystatin C Levels

OBJECTIVE

The aim of the present study was to examine serum cystatin C levels in association with the Mediterranean diet in a healthy Greek population.

METHODS

Cystatin C together with basic clinical chemistry tests was measured in a total of 490 adults (46±16 years, 40% of males), who underwent an annual health check. Demographic, anthropometric and lifestyle characteristics were recorded, while adherence to the Mediterranean diet was evaluated through the MedDietScore (0-55).

RESULTS

The mean level of serum cystatin C was 0.84 mg/L, while men had increased serum cystatin C levels compared to women (0.86 mg/L vs. 0.83 mg/L, respectively, 0.017). After adjusting for age, gender, body mass index, smoking status, hypertension, diabetes, hypercholesterolemia, estimated glomerular filtration rate (eGFR), albumin and ferritin levels, each unit increase in MedDietScore led to 0.002 mg/dL drop off in cystatin C serum levels.

CONCLUSIONS

We have demonstrated an inverse relationship between the MedDietScore and serum cystatin C levels. Our finding that increases in MedDietScore are associated with decreases in serum cystatin C levels could imply that adherence to the Mediterranean diet may reduce the cardiovascular risk, as assessed by cystatin C, a prognostic marker of the cardiometabolic risk. This notion could have a great impact on public health.

Diabetic hepatosclerosis: True clinical entity or ghost disease?

Diabetic hepatosclerosis is a novel entity that has recently been introduced by reviewing archived liver biopsies as a non-cirrhotic form of peri-sinusoidal fibrosis with basement membrane formation. Diabetic hepatosclerosis is usually characterized by an indolent clinical course. Serum aminotransferase levels are normal or minimally elevated, but elevated alkaline phosphatase levels is usually present. Clinically relevant to DH is the co-existence of other diabetic microvascular complications in the same patient, such as ESRD on long-term dialysis or renal transplantation, retinopathy, or neuropathy. Although it seems that DH occurs in patients with type 1 more often than type 2 diabetes mellitus, the true prevalence of this entity still remains unknown. Future prospective studies should include long-term follow-up to examine the natural history and to explore treatment options for this form of hepatic micro-angiopathy disease.

SGLT-2 inhibitors: Their pleiotropic properties

Type 2 diabetes mellitus has become a global pandemic. Nowadays, it is estimated that approximately 415 million people all over the world have diabetes. The sodium glucose co-transporters 2 inhibitors are a new class of glucose-lowering agents, which act through a novel mechanism by producing a decline in glucose re-absorption in the kidney, thereby increasing glycosuria and decreasing serum glucose levels. Data suggest that apart from lowering HbA1c, they produce a small but significant weight loss and a small decrease in blood pressure. Also, they possess nephro-protective potential. These drugs are demonstrated to restore intra-glomerular pressure by increasing angiotensin (1-7), which exerts vasodilatory and anti-inflammatory effects. Their profile on cardiovascular events is still under investigation. In this review, the pleiotropic potential of this novel class of glucose-lowering levels will be discussed. Further research is warranted to determine their safety in the long term.

Potential anticancer properties and mechanisms of action of curcumin

Curcumin, a yellow substance belonging to the polyphenols superfamily, is the active component of turmeric, a common Indian spice, which is derived from the dried rhizome of the Curcuma longa plant. Numerous studies have demonstrated that curcumin possesses anti-oxidant, anti-inflammatory and anticancerous properties. The purpose of this review is to focus on the anti-tumor effects of curcumin. Curcumin inhibits the STAT3 and NF-κB signaling pathways, which play key-roles in cancer development and progression. Also, inhibition of Sp-1 and its housekeeping gene expressions may serve as an important hypothesis to prevent cancer formation, migration, and invasion. Recent data have suggested that curcumin may act by suppressing the Sp-1 activation and its downstream genes, including ADEM10, calmodulin, EPHB2, HDAC4, and SEPP1 in a concentration-dependent manner in colorectal cancer cell lines; these results are consistent with other studies, which have reported that curcumin could suppress the Sp-1 activity in bladder cancer and could decrease DNA binding activity of Sp-1 in non-small cell lung carcinoma cells. Recent data advocate that ER stress and autophagy may as well play a role in the apoptosis process, which is induced by the curcumin analogue B19 in an epithelial ovarian tumor cell line and that autophagy inhibition could increase curcumin analogue-induced apoptosis by inducing severe ER stress. The ability of curcumin to induce apoptosis in tumor cells and its anti-angiogenic potential will be discussed in this review.

Statins and cancer

Statins have pleiotropic properties and might exert an effect even in the field of cancer. Statins competitively inhibit 3-hydroxy-3-methylglutaryl coenzyme (HMG-CoA) reductase, the major rate-limiting enzyme that controls the conversion of HMG-CoA to mevalonic acid. Specifically, inhibition of HMG-CoA reductase by statins has been proved to prevent the synthesis of mevalonic acid, a precursor of non-steroidal isoprenoids, which are lipid attachment molecules for small G proteins, such as Ras, Rho and Rac. Thus, statins may inhibit the synthesis of isoprenoids and thereby suppress the activation of small G proteins. In addition, statins exert pro-apoptotic, anti-angiogenic, and immunomodulatory effects, which may prevent cancer growth. Statins may inhibit the growth of a variety of cancer cell types, including breast, gastric, pancreatic, and prostate carcinoma, neuroblastoma, melanoma, mesothelioma and acute myeloid leukemia cells. They exert pro-apoptotic effects in a wide range of cancer cell lines, but with many differences in the sensitivity to statin-induced cell death among different cancer cell types. Regarding anti-angiogenic effects, multiple statin effects on blood vessel formation by inhibition of angiogenesis through down-regulation of pro-angiogenic factors, such as vascular endothelial growth factor, inhibition of endothelial cell proliferation and inhibition of adhesion to extracellular matrix by blocking intercellular adhesion molecules have been suggested. The molecular mechanisms of statin immunomodulation often implicate multiple pathways, regarding the regulation of genes encoding key molecules, which are involved in antigen presentation and subsequent immunomodulation. Another mechanism involves the down-regulation of the nuclear factor-kappa-B, which is responsible for the transcription of many genes involved in immunologic mechanisms, such as interferon-inducible protein-10, monocyte chemo-attractant protein 1 and cyclooxygenase-2. Statins have been associated with a significantly lower risk of breast, colorectal, ovarian, pancreatic, lung cancers and lymphoma in several observational studies. On the other hand, other studies, including meta-analyses have raised concerns about the safety of statins among elderly patients. A recent study upon the relationship between statin use (prior to cancer diagnosis) and cancer-related mortality in the entire Danish population from 1995-2009 in adults > 40 years of age has been conducted. As compared to statin non-users, patients using statins prior to cancer diagnosis were 15% less likely to die from any cause or cancer specifically. Further investigation is needed to elaborate on their mode of action as well as their true significance on cancer prevention and perhaps as an adjuvant to cancer chemotherapy.

The therapeutic potential of milk thistle in diabetes

Milk thistle has been known for more than 2.000 years as a herbal remedy for a variety of disorders. It has mainly been used to treat liver and gallbladder diseases. Silibum marianum, the Latin term for the plant, and its seeds contain a whole family of natural compounds, called flavonolignans. Silimarin is a dry mixture of these compounds; it is extracted after processing with ethanol, methanol, and acetone. Silimarin contains mainly silibin A, silibin B, taxifolin, isosilibin A, isosilibin B, silichristin A, silidianin, and other compounds in smaller concentrations. Apart from its use in liver and gallbladder disorders, milk thistle has recently gained attention due to its hypoglycemic and hypolipidemic properties. Recently, a substance from milk thistle has been shown to possess peroxisome proliferator-activated receptor γ (PPARγ) agonist properties. PPARγ is the molecular target of thiazolidinediones, which are used clinically as insulin sensitizers to lower blood glucose levels in diabetes type 2 patients. The thiazolidinedione type of PPARγ ligands is an agonist with a very high binding affinity. However, this ligand type demonstrates a range of undesirable side effects, thus necessitating the search for new effective PPARγ agonists. Interestingly, studies indicate that partial agonism of PPARγ induces promising activity patterns by retaining the positive effects attributed to the full agonists, with reduced side effects. In this review, the therapeutic potential of milk thistle in the management of diabetes and its complications are discussed.

Resveratrol and diabetes

Resveratrol is a stilbene compound, and a phytoalexin, synthesized by plants in response to stressful stimuli, usually caused by infection. It is abundantly present in red wine, ports and sherries, red grapes, blueberries, peanuts, itadori tea, as well as hops, pistachios, and in grape and cranberry juices. The anti-hyperglycemic effects of resveratrol seem to be the result of an increased action of the glucose transporter in the cytoplasmic membrane. Studies on rats with streptozotocin-induced diabetes have demonstrated that the expression of the insulin-dependent glucose transporter, GLUT4, is increased after resveratrol ingestion. Also, resveratrol enhances adiponectin levels, which could be one of the potential mechanisms by which it improves insulin sensitivity. Another important observation is that resveratrol induces the secretion of the gut incretin hormone, glucagon-like peptide-1. Resveratrol is also reported to activate Sir2 (silent information regulatory 2), a SIRT1 homolog, thus mimicking the benefits of calorie restriction. It produces a wide variety of effects in mammalian cells, including activation of AMP-activated protein kinase, which is involved in some of the same metabolic pathways as SIRT1, which may influence other mechanisms via the involvement of nuclear factor kappa B (NF-κB). In the near future, resveratrol-based therapies with either resveratrol or its analogs that have better bioavailability could be useful in the treatment of diabetes and its complications, either alone or in combination with other anti-diabetic drugs.