Current Medicinal Chemistry - Volume 25, Issue 37, 2018

Algae have been consumed for many years in Asian countries; at present, its consumption around the world either as food ingredient or directly as food commodity has increased considerably mainly due to the Asian influence and its cuisine, but also because of the growing interest in the beneficial health effects of algae. Although several biological activities have been attributed to different algae compounds such as pigments, lipids, polysaccharides, fiber, proteins or vitamins, in the present review we will highlight the different phenolic compounds present on seaweeds and their important role in the functional and health effects, paying special attention to the antioxidant, anti-proliferative, anti-obesity and antidiabetic activities.

Diabetes mellitus is a complex metabolic disease characterized by high blood sugar levels. Different pathogenic processes are involved in the etiology of the disease. Indeed, chronic diabetes hyperglycemia is often associated with severe long-term complications including cardiovascular symptoms, retinopathy, nephropathy, and neuropathy. Although the precise molecular mechanisms underlying diabetes are not yet clear, it is widely accepted that increased levels of oxidative stress are involved in the onset, development and progression of diabetes and its related complications. In this regard, the use of natural antioxidant polyphenols, able to control free radical production, to increase intracellular antioxidant defense and to prevent the onset of oxidative stress, can be of high interest. Caffeic acid phenethyl ester (CAPE), a natural polyphenolic substance, is one of the main components of propolis. Due to its multifaceted biological activities, including antioxidant, antimicrobial, anti-inflammatory, antitumor, and immunomodulatory effects, CAPE has received great attention during the last few decades. In the present paper the therapeutic potential of CAPE in diabetes is extensively reviewed.

Background: Obesity in the 21st century society became an important health problem, alarming both the scientists and medicine doctors around the world. That is why, the search for new drug candidates capable to reduce the body weight is of high concern. Objective: This contribution tends to collect current findings on the biochemistry of obesity and on the application of plants and in particular turmeric tuber – a commonly used spice - as an anti-obesity agent. Methods: Following an introduction on the biochemical characteristics of obesity, the description of Curcuma secondary metabolites, their pharmacological applications and a study on the plants’ regulatory properties in obesity was summarized. Particular attention was paid to curcumin – the major metabolite present in the extracts of Curcuma spp., which is known to exhibit a variety of pharmacological actions. Also, the characteristics of some semisynthetic analogues of this ferulic acid derivative, characterized by a higher polarity and better bioavailability will be discussed. Results: Numerous scientific papers treat on the influence of turmeric on weight loss. Additionally, some of them describe its anti-inflammatory properties. Conclusions: This important spice tends to fight the 21st century plague, which is an excessive weight gain, related to the development of metabolic syndrome, to the occurrence of cardiovascular problems and diabetes, and, in consequence, leading to a significant shortening of life span. As herein proven, the extracts of turmeric play an important role in the regulation of inflammatory reactions which are evoked in the overweight patients, helping them reduce the excess body weight.

Crataegus oxyacantha L. (syn. C. rhipidophylla Gand.) (Rosac-eae) is one of the two medicinally recognized hawthorn species in European Pharmacopeia. Standardization of the extract prepared from the berry and flowers of the plant is required according to its oligomeric procyanidins. C. oxyacantha is well-known for its use in the treatment of various heart problems particularly, including heart failure in cases of declining cardiac performance equivalent to stages I and II of the New York Heart Association classification, angina pectoris, hypertension with myocardial insufficiency, mild alterations of cardiac rhythm, and atherosclerosis. C. oxyacantha has been reported to exert several other pharmacological activities such as hypotensive, antihyperlipidemic, antihyperglycemic, anxiolytic, immunomodulatory, and antimutagenic. Oligomeric procyanidins and flavone/flavonol types of flavonoids, which are considered to be the chief groups of active substances, phenolic acids, triterpenes, fatty acids, and sterols are present in the plant. The present review aims mainly to outline cardiotonic effect of C. oxyacantha as well as its brief phytochemistry. Numerous experiments and clinical studies have underlined cardiovascular efficacy of the plant through various mechanisms including positive inotropic and negative chronotropic effects, escalation in coronary blood flow and exercise tolerance, inhibition of the enzymes such as angiotensinconverting enzyme (ACE) and phosphodiesterase, anti-inflammatory and antihyperlipidemic effects, improving status of antioxidant enzymes, etc., which support its cardioactive efficacy. The plant possesses several other bioactivities for human health usually concomitant to its rich polyphenolic content.

Ursolic acid, a natural pentacyclic triterpenoid is commonly found in plants and foods with promising biological and pharmacological activities. The compound has been under the attention of researchers due to its considerable anticancer effects through suppression of differentiation, angiogenesis, invasion, and metastasis of tumor cells via different pathways with low toxicity. Bioavailability of ursolic acid is poor due to poor solubility of the compound in water. Low bioavailability and short plasma half-life of ursolic acid along with non-specific distribution in the body are considered as impediments in the therapeutic development of the compound. Nano-drug delivery systems may improve the pharmacokinetic, bioavailability, and therapeutic activity of some medicines. The present review has focused on recent developments regarding nano-drug delivery systems of ursolic acid in cancer therapy.

Quercetin has multiple potential to control various cell function keeping our body condition healthy. In this review article, we describe the molecular mechanism on how quercetin exerts its action on blood pressure, neurite elongation and epithelial ion transport based from a viewpoint of cytosolic Cl- environments, which is recently recognized as an important signaling factor in various types of cells. Recent studies show various roles of cytosolic Cl- in regulation of blood pressure and neurite elongation, and prevention from bacterial and viral infection. We have found the stimulatory action of quercetin on Cl- transporter, Na+-K+-2Cl- cotransporter 1 (NKCC1; an isoform of NKCC), which has been recognized as one of the most interesting, fundamental actions of quercetin. In this review article, based on this stimulatory action of quercetin on NKCC1, we introduce the molecular mechanism of quercetin on: 1) blood pressure, 2) neurite elongation, and 3) epithelial Cl- secretion including tight junction forming in epithelial tissues. 1) Quercetin induces elevation of the cytosolic Cl- concentration via activation of NKCC1, leading to anti-hypertensive action by diminishing expression of epithelial Na+ channel (ENaC), a key ion channel involved in renal Na+ reabsorption, while quercetin has no effects on the blood pressure with normal salt intake. 2) Quercetin also has stimulatory effects on neurite elongation by elevating the cytosolic Cl- concentration via activation of NKCC1 due to tubulin polymerization facilitated through Cl--induced inhibition of GTPase. 3) Further, in lung airway epithelia quercetin stimulates Cl- secretion by increasing the driving force for Cl- secretion via elevation of the cytosolic Cl- concentration: this leads to water secretion, participating in prevention of our body from bacterial and viral infection. In addition to transcellular ion transport, quercetin regulates tight junction function via enhancement of tight junction integrity by modulating expression and assembling tight junction-forming proteins. Based on these observations, it is concluded that quercetin is a useful medicinal compound keeping our body to be in healthy condition.

The consumption of berry-type fruits has become very popular in recent years because of their positive effects on human health. Berries are in fact widely known for their health-promoting benefits, including prevention of chronic disease, cardiovascular disease and cancer. Berries are a rich source of bioactive metabolites, such as vitamins, minerals, and phenolic compounds, mainly anthocyanins. Numerous in vitro and in vivo studies recognized the health effects of berries and their function as bioactive modulators of various cell functions associated with oxidative stress. Plants have one of the largest metabolome databases, with over 1200 papers on plant metabolomics published only in the last decade. Mass spectrometry (MS) and NMR (Nuclear Magnetic Resonance) are the most important analytical technologies on which the emerging "omics" approaches are based. They may provide detection and quantization of thousands of biologically active metabolites from a tissue, working in a "global" or "targeted" manner, down to ultra-trace levels. In the present review, we highlighted the use of MS and NMR-based strategies and Multivariate Data Analysis for the valorization of berries known for their biological activities, important as food and often used in the preparation of nutraceutical formulations.

This review gives an overview of the phenolic compounds composition of cocoa beans and their modification during manufacturing processes to the final products. Recently published papers dealing with the qualitative and quantitative analysis of the different classes of cocoa phenolic compounds will be discussed. Modifications of the qualitative profile and amount of phenolic compounds in cocoa after the main processes of production chain, fermentation, drying, roasting, and alkalization, will be described. The second part will focus on some of the biological effects described for cocoa phenolic compounds in vitro and in vivo. In particular, the effects of cocoa flavanols on cardiovascular health and endothelial function have been extensively investigated over the last decades, with interesting results from nutritional intervention trials and molecular studies. A few recent updates on the role of cocoa and chocolate consumption on sport performances will be reported.

Recently many studies showed anticancer activities of piperine, a pungent alkaloid found in black pepper and some other Piper species. We attempted to summarize acquired data that support anticancer potential of this natural agent. Piperine has been reported to possess effective chemopreventive activity. It has been studied to affect via several mechanisms of action, in brief enhancing antioxidant system, increasing level and activity of detoxifying enzymes and suppressing stem cell self-renewal. Moreover, piperine has been found to inhibit proliferation and survival of various cancerous cell lines via modulating cell cycle progression and exhibiting anti-apoptotic activity, respectively. This compound has been shown to modify activity of various enzymes and transcription factors to inhibit invasion, metastasis and angiogenesis. Interestingly, piperine has exhibited antimutagenic activity and also inhibited activity and expression of multidrug resistance transporters such as P-gp and MRP-1. Besides, about all reviewed studies have reported selective cytotoxic activity of piperine on cancerous cells in compared with normal cells. Altogether, the studies completely underline promising candidacy of piperine for further development. The collected preclinical data we provided in this article can be useful in the design of future researches especially clinical trials with piperine.

Background: The benefits of the Mediterranean diet for protecting against many diseases are usually attributed to high consumption of certain foods, characterized by the presence of bioactive substances such as polyphenols. Inflammation plays an important role in the pathogenesis of numerous diseases such as arthritis, allergies or neurodegenerative disorders. Dietary polyphenols constitute a large family of bioactive substances with potential beneficial effects against a broad group of diseases. Citrus fruits and juices are a rich source of vitamin C and flavonoids, with a potential effect on the inflammatory response. Objective: The aim was to evidence the potential anti-inflammatory effects of the flavonoids hesperidin for its possible therapeutic application against diverse pathologies. Method: In the present review, available literature about the anti-inflammatory effects of hesperidin is reported and discussed. Moreover, we also discuss the chemistry, bioavailability and proposed mechanisms of action of hesperidin. Results: Hesperidin is a flavonoid present in high concentration in citrus species and has numerous biological properties, principally antioxidant and anti-inflammatory. Several studies have been performed in order to evaluate the effects of hesperidin as anti-inflammatory agent using cellular and animal models and few clinical trials. Hesperidin treatment decreased inflammatory mediators and exerted significant antioxidant effects. The molecular basis for its anti-inflammatory effects seems to be mediated by signalling pathways especially the nuclear factor Κβ pathway. Conclusion: Although hesperidin evidenced anti-inflammatory effects, the specific mechanism of action is not completely known and additional studies are required for elucidation of the molecular targets.

The popularity of food products and medicinal plant materials containing hydrolysable tannins (HT) is nowadays rapidly increasing. Among various health effects attributable to the products of plant origin rich in gallotannins and/or ellagitannins the most often underlined is the beneficial influence on diseases possessing inflammatory background. Results of clinical, interventional and animal in vivo studies clearly indicate the antiinflammatory potential of HT-containing products, as well as pure ellagitannins and gallotannins. In recent years a great emphasis has been put on the consideration of metabolism and bioavailability of natural products during examination of their biological effects. Conducted in vivo and in vitro studies of polyphenols metabolism put a new light on this issue and indicate the gut microbiota to play a crucial role in the health effects following their oral administration. The aim of the review is to summarize the knowledge about HT-containing products' phytochemistry and their anti-inflammatory effects together with discussion of the data about observed biological activities with regards to the current concepts on the HTs' bioavailability and metabolism. Orally administered HT-containing products due to the limited bioavailability of ellagitannins and gallotannins can influence immune response at the level of gastrointestinal tract as well as express modulating effects on the gut microbiota composition. However, due to the chemical changes being a result of their transit through gastrointestinal tract, comprising of hydrolysis and gut microbiota metabolism, the activity of produced metabolites has to be taken into consideration. Studies regarding biological effects of the HTs' metabolites, in particular urolithins, indicate their strong and structure-dependent anti-inflammatory activities, being observed at the concentrations, which fit the range of their established bioavailability. The impact of HTs on inflammatory processes has been well established on various in vivo and in vitro models, while influence of microbiota metabolites on silencing the immune response gives a new perspective on understanding anti-inflammatory effects attributed to HT containing products, especially their postulated effectiveness in inflammatory bowel diseases (IBD) and cardiovascular diseases.