Hypolipidemic and antioxidant effects of hydroxycinnamic acids, quercetin, and cyanidin 3-glucoside in hypercholesterolemic erythrocytes (in vitro study)

Flavonoids: A treasure house of prospective pharmacological potentials

Flavonoids are organic compounds characterized by a range of phenolic structures, which are abundantly present in various natural sources such as fruits, vegetables, cereals, bark, roots, stems, flowers, tea, and wine. The health advantages of these natural substances are renowned, and initiatives are being taken to extract the flavonoids. Apigenin, galangin, hesperetin, kaempferol, myricetin, naringenin, and quercetin are the seven most common compounds belonging to this class. A thorough analysis of bibliographic records from reliable sources including Google Scholar, Web of Science, PubMed, ScienceDirect, MEDLINE, and others was done to learn more about the biological activities of these flavonoids. These flavonoids appear to have promising anti-diabetic, anti-inflammatory, antibacterial, antioxidant, antiviral, cytotoxic, and lipid-lowering activities, according to evidence from in vitro, in vivo, and clinical research. The review contains recent trends, therapeutical interventions, and futuristic aspects of flavonoids to treat several diseases like diabetes, inflammation, bacterial and viral infections, cancers, and cardiovascular diseases. However, this manuscript should be handy in future drug discovery. Despite these encouraging findings, a notable gap exists in clinical research, hindering a comprehensive understanding of the effects of flavonoids at both high and low concentrations on human health. Future investigations should prioritize exploring bioavailability, given the potential for high inter-individual variation. As a starting point for further study on these flavonoids, this review paper may promote identifying and creating innovative therapeutic uses.

Roles of CcDFR and CcOMT9 in the cyanidin biosynthesis and development of Cordyceps cicadae

Introduction

Cordyceps cicadae is a traditional Chinese medicinal fungus known for its rich production of bioactive substances, particularly cyanidin, an anthocyanin commonly found in plants with notable anti-inflammatory, anti-tumor, antiviral, and antibacterial properties. This study revealed two key genes, CcDFR and CcOMT9, affecting cyanidin biosynthesis in C. cicadae.

Methods

The roles of these genes in cyanidin production, growth, and development were elucidated through the gene knockout method, phenotypic analysis, transcriptomics, and metabolomics.

Results

CcDFR deletion led to reduced cyanidin-3-O-glucoside (C3G), suppressed expression of cyanidin biosynthesis genes, impaired synnemata formation, decreased polysaccharide and adenosine content, and diminished chitinase activity. Meanwhile, the ΔCcOMT9 mutant exhibited an increase in C3G production, promoted expression of cyanidin biosynthesis genes and rising bioactive compounds, suppressed RNA methylation, and led to phenylalanine accumulation with no effect on fruiting body formation.

Discussion

We revealed a distinct anthocyanin biosynthesis pathway in C. cicadae and identified two genes with opposite functions, laying the foundation for future genetic modification of cyanidin-producing strains using modern biological techniques. This will shorten the production period of this valuable compound, facilitating the industrial-scale production of cyanidin.

Activity of Na+/K+- and Ca2+-ATPases in human erythrocyte membranes: Protocol improvement, relation to cholesterol content, and effects of polyphenols

It is known that the activities of Na+/K+- and Ca2+-ATPases in the plasma membrane with an excess of cholesterol are compromised. Our main goal was to find out whether quercetin, resveratrol, or caffeic acid, in the nano- and low micromolar concentration ranges, can improve the ATPase activity in human erythrocyte membranes with excess cholesterol. These molecules belong to different chemical classes of polyphenols and are widely present in plant foods. Also, due to some variations in the protocol for determining the ATPase activity, we first analyzed several key parameters of the protocol to improve the accuracy of the results. The activities of Na+/K+- and Ca2+-ATPases were reduced in membranes with moderate and high cholesterol levels compared to membranes from normocholesterolemic subjects (p < 0.01). All three polyphenols affected the ATPase activity in a similar biphasic manner. Namely, the ATPase activity gradually increased with increasing polyphenol concentration up to 80-200 nM, and then gradually decreased with further increase in polyphenol concentration. Moreover, the stimulating effect of the polyphenols was highest in membranes with high cholesterol content, making ATPase activity values close/equal to those in normal cholesterol membranes. In other words, quercetin, resveratrol, and caffeic acid at nanomolar concentrations were able to improve/restore the functioning of Na+/K+- and Ca2+-ATPases in erythrocyte membranes with high cholesterol levels. This suggests a common membrane-mediated mechanism of action for these polyphenols, related to the content of membrane cholesterol.

Bioactive Substances and Biological Functions in Malus hupehensis: A Review

Malus hupehensis (MH), as a natural resource, contains various active ingredients such as polyphenols, polysaccharides, proteins, amino acids, volatile substances, and other components. Increasingly, studies have indicated that MH showed a variety of biological activities, including antioxidant, hypoglycemic, hypolipidemic, anti-cancer, anti-inflammatory activities, and other activities. Hence, MH has attracted wide interest because of its high medical and nutritional value. It is necessary to review the active components and biological activities of MH. This paper systematically reviewed the chemical substances, biological activities, and potential problems of MH to further promote the related research of MH and provide an important reference for its application and development in medicine and food.

Protective Effects of Ferulic Acid on Metabolic Syndrome: A Comprehensive Review

Metabolic syndrome (MetS) is a complex disease in which protein, fat, carbohydrates and other substances are metabolized in a disorderly way. Ferulic acid (FA) is a phenolic acid found in many vegetables, fruits, cereals and Chinese herbs that has a strong effect on ameliorating MetS. However, no review has summarized the mechanisms of FA in treating MetS. This review collected articles related to the effects of FA on ameliorating the common symptoms of MetS, such as diabetes, hyperlipidemia, hypertension and obesity, from different sources involving Web of Science, PubMed and Google Scholar, etc. This review summarizes the potential mechanisms of FA in improving various metabolic disorders according to the collected articles. FA ameliorates diabetes via the inhibition of the expressions of PEPCK, G6Pase and GP, the upregulation of the expressions of GK and GS, and the activation of the PI3K/Akt/GLUT4 signaling pathway. The decrease of blood pressure is related to the endothelial function of the aortas and RAAS. The improvement of the lipid spectrum is mediated via the suppression of the HMG-Co A reductase, by promoting the ACSL1 expression and by the regulation of the factors associated with lipid metabolism. Furthermore, FA inhibits obesity by upregulating the MEK/ERK pathway, the MAPK pathway and the AMPK signaling pathway and by inhibiting SREBP-1 expression. This review can be helpful for the development of FA as an appreciable agent for MetS treatment.

Bioactivity and Therapeutic Potential of Kaempferol and Quercetin: New Insights for Plant and Human Health

Plant secondary metabolites, especially flavonoids, are major metabolites widely found in plants that play several key roles in plant defence and signalling in response to stress conditions. The most studied among these flavonoids are kaempferol and quercetin due to their anti-oxidative potential and their key roles in the defence system, making them more critical for plant adaptation in stress environments. Kaempferol and quercetin in plants have great therapeutic potential for human health. Despite being well-studied, some of their functional aspects regarding plants and human health need further evaluation. This review summarizes the emerging potential of kaempferol and quercetin in terms of antimicrobial activity, bioavailability and bioactivity in the human body as well as in the regulation of plant defence in response to stresses and as a signalling molecule in terms of hormonal modulation under stress conditions. We also evaluated the safe use of both metabolites in the pharmaceutical industry.

Antioxidant Activity of Quercetin in a H2O2-Induced Oxidative Stress Model in Red Blood Cells: Functional Role of Band 3 Protein

During their lifespan, red blood cells (RBCs) are exposed to a large number of stressors and are therefore considered as a suitable model to investigate cell response to oxidative stress (OS). This study was conducted to evaluate the potential beneficial effects of the natural antioxidant quercetin (Q) on an OS model represented by human RBCs treated with H₂O₂. Markers of OS, including % hemolysis, reactive oxygen species (ROS) production, thiobarbituric acid reactive substances (TBARS) levels, oxidation of protein sulfhydryl groups, CD47 and B3p expression, methemoglobin formation (% MetHb), as well as the anion exchange capability through Band 3 protein (B3p) have been analyzed in RBCs treated for 1 h with 20 mM H₂O₂ with or without pre-treatment for 1 h with 10 μM Q, or in RBCs pre-treated with 20 mM H₂O₂ and then exposed to 10 µM Q. The results show that pre-treatment with Q is more effective than post-treatment to counteract OS in RBCs. In particular, pre-exposure to Q avoided morphological alterations (formation of acanthocytes), prevented H₂O₂-induced OS damage, and restored the abnormal distribution of B3p and CD47 expression. Moreover, H₂O₂ exposure was associated with a decreased rate constant of SO₄²⁻ uptake via B3p, as well as an increased MetHb formation. Both alterations have been attenuated by pre-treatment with 10 μM Q. These results contribute (1) to elucidate OS-related events in human RBCs, (2) propose Q as natural antioxidant to counteract OS-related alterations, and (3) identify B3p as a possible target for the treatment and prevention of OS-related disease conditions or aging-related complications impacting on RBCs physiology.

Composition and Antioxidant Activity of Anthocyanins and Non-Anthocyanin Flavonoids in Blackberry from Different Growth Stages

The high nutritional value and unique flavor of blackberries make them a popular food choice among consumers. Anthocyanin content (AC) and non-anthocyanin flavonoid content (NAFC) are important functional components in blackberry. We tested the AC, NAFC, and antioxidant activities of two blackberry—Ningzhi 1 and Hull—during the following ripening stages: green-fruit stage (GFS), color-turning stage (CTS), reddening stage (RDS), and ripening stage (RPS). The results showed that NAFC decreased and AC increased gradually during the ripening stages. The NAFC of Hull blackberry was the highest during GFS (889.74 μg/g), while the AC of Ningzhi 1 blackberry was the highest during RPS (1027.08 μg/g). NAFC was the highest at the initial stage and gradually decreased with ripening. Anthocyanin accumulation mainly occurred during the later ripening stages. These results provide a reference for comparing the NAFC, AC, and antioxidant activity of Ningzhi 1 and Hull and their changes during different ripening stages.

Circulating miRNA profiles in mice plasma following flavonoid intake

BACKGROUND

Polyphenols, including flavonoids, have been the focus of numerous studies that have revealed diverse health benefits. MicroRNAs (miRNAs) constitute a class of small non-coding RNAs that function as posttranscriptional regulators of gene expression. miRNAs can be detected in the blood and these so-called circulating miRNAs are potential biomarkers of various diseases. This study aimed to explore circulating miRNAs in plasma as a means to predict the biological effects of functional food ingredients.

METHODS AND RESULTS

We used miRNA microarray analysis to compare plasma miRNA levels in mice orally administered three flavonoids (daidzein, quercetin, and delphinidin). Several miRNAs were differentially expressed in plasma from mice in each treatment group compared with the vehicle-treated group. The plasma levels of miR-25-5p, miR-146b-5p, and miR-501-3p were increased in the flavonoid-treated and the plasma levels of miR-148b-3p, miR-669e-5p, and miR-3962 were decreased.

CONCLUSIONS

Our findings suggested that flavonoids alter miRNA expression in plasma and identified promising plasma miRNAs for assessing the functionality of flavonoids.

Combined Treatment with Curcumin and Ferulic Acid Suppressed the Aβ-Induced Neurotoxicity More than Curcumin and Ferulic Acid Alone

Alzheimer’s disease (AD) is a neurodegenerative disease that leads to progressive cognitive decline. Several effective natural components have been identified for the treatment of AD. However, it is difficult to obtain conclusive evidence on the safety and effectiveness of natural components, because a variety of factors are associated with the progression of AD pathology. We hypothesized that a therapeutic effect could be achieved by combining multiple ingredients with different efficacies. The purpose of this study was thus to evaluate a combination treatment of curcumin (Cur) and ferulic acid (FA) for amyloid-β (Aβ)-induced neuronal cytotoxicity. The effect of Cur or FA on Aβ aggregation using thioflavin T assay was confirmed to be inhibited in a concentration-dependent manner by Cur single or Cur + FA combination treatment. The effects of Cur + FA on the cytotoxicity of human neuroblastoma (SH-SY5Y) cells induced by Aβ exposure were an increase in cell viability, a decrease in ROS and mitochondrial ROS, and repair of membrane damage. Combination treatment showed an overall higher protective effect than treatment with Cur or FA alone. These results suggest that the combined action mechanisms of Cur and FA may be effective in preventing and suppressing the progression of AD.

Oxidation Stress as a Mechanism of Aging in Human Erythrocytes: Protective Effect of Quercetin

Aging is a multi-factorial process developing through a complex net of interactions between biological and cellular mechanisms and it involves oxidative stress (OS) as well as protein glycation. The aim of the present work was to verify the protective role of Quercetin (Q), a polyphenolic flavonoid compound, in a d-Galactose (d-Gal)-induced model of aging in human erythrocytes. The anion-exchange capability through the Band 3 protein (B3p) measured by the rate constant of the SO₄²⁻ uptake, thiobarbituric acid reactive substances (TBARS) levels—a marker of lipid peroxidation—total sulfhydryl (-SH) groups, glycated hemoglobin (A1c), and a reduced glutathione/oxidized glutathione (GSH-GSSG) ratio were determined following the exposure of erythrocytes to 100 mM d-Gal for 24 h, with or without pre-incubation with 10 µM Q. The results confirmed that d-Gal activated OS pathways in human erythrocytes, affecting both membrane lipids and proteins, as denoted by increased TBARS levels and decreased total sulfhydryl groups, respectively. In addition, d-Gal led to an acceleration of the rate constant of the SO₄²⁻ uptake through the B3p. Both the alteration of the B3p function and oxidative damage have been improved by pre-treatment with Q, which preferentially ameliorated lipid peroxidation rather than protein oxidation. Moreover, Q prevented glycated A1c formation, while no protective effect on the endogenous antioxidant system (GSH-GSSG) was observed. These findings suggest that the B3p could be a novel potential target of antioxidant treatments to counteract aging-related disturbances. Further studies are needed to confirm the possible role of Q in pharmacological strategies against aging.

Cardioprotective effects of phytopigments via multiple signaling pathways

BACKGROUND

Cardiovascular diseases (CVDs) are among the deadliest non-communicable diseases, and millions of dollars are spent every year to combat CVDs. Unfortunately, the multifactorial etiology of CVDs complicates the development of efficient therapeutics. Interestingly, phytopigments show significant pleiotropic cardioprotective effects both in vitro and in vivo.

PURPOSE

This review gives an overview of the cardioprotective effects of phytopigments based on in vitro and in vivo studies as well as clinical trials.

METHODS

A literature-based survey was performed to collect the available data on cardioprotective activities of phytopigments via electronic search engines such as PubMed, Google Scholar, and Scopus.

RESULTS

Different classes of phytopigments such as carotenoids, xanthophylls, flavonoids, anthocyanins, anthraquinones alleviate major CVDs (e.g., cardiac hypertrophy, atherosclerosis, hypertension, cardiotoxicities) via acting on signaling pathways related to AMPK, NF-κB, NRF2, PPARs, AKT, TLRs, MAPK, JAK/STAT, NLRP3, TNF-α, and RA.

CONCLUSION

Phytopigments represent promising candidates to develop novel and effective CVD therapeutics. More randomized, placebo-controlled clinical studies are recommended to establish the clinical efficacy of phytopigments.

Beneficial Effect of Quercetin on Erythrocyte Properties in Type 2 Diabetic Rats

Diabetes mellitus is characterized by tissue oxidative damage and impaired microcirculation, as well as worsened erythrocyte properties. Measurements of erythrocyte deformability together with determination of nitric oxide (NO) production and osmotic resistance were used for the characterization of erythrocyte functionality in lean (control) and obese Zucker diabetic fatty (ZDF) rats of two age categories. Obese ZDF rats correspond to prediabetic (younger) and diabetic (older) animals. As antioxidants were suggested to protect erythrocytes, we also investigated the potential effect of quercetin (20 mg/kg/day for 6 weeks). Erythrocyte deformability was determined by the filtration method and NO production using DAF-2DA fluorescence. For erythrocyte osmotic resistance, we used hemolytic assay. Erythrocyte deformability and NO production deteriorated during aging-both were lower in older ZDF rats than in younger ones. Three-way ANOVA indicates improved erythrocyte deformability after quercetin treatment in older obese ZDF rats only, as it was not modified or deteriorated in both (lean and obese) younger and older lean animals. NO production by erythrocytes increased post treatment in all experimental groups. Our study indicates the potential benefit of quercetin treatment on erythrocyte properties in condition of diabetes mellitus. In addition, our results suggest potential age-dependency of quercetin effects in diabetes that deserve additional research.

Changes in Human Erythrocyte Membrane Exposed to Aqueous and Ethanolic Extracts from Uncaria tomentosa

Uncaria tomentosa (Willd.) DC is a woody climber species originating from South and Central America that has been used in the therapy of asthma, rheumatism, hypertension, and blood purification. Our previous study showed that U. tomentosa extracts altered human erythrocyte shape, which could be due to incorporation of the compounds contained in extracts into the erythrocyte membrane. The aim of the present study was to determine how the compounds contained in U. tomentosa extracts incorporate into the human erythrocyte membrane. The study has assessed the effect of aqueous and ethanolic extracts from leaves and bark of U. tomentosa on the osmotic resistance of the human erythrocyte, the viscosity of erythrocyte interior, and the fluidity of erythrocyte plasma membrane. Human erythrocytes were incubated with the studied extracts in the concentrations of 100, 250, and 500 µg/mL for 2, 5, and 24 h. All extracts tested caused a decrease in erythrocyte membrane fluidity and increased erythrocyte osmotic sensitivity. The ethanolic extracts from the bark and leaves increased viscosity of the erythrocytes. The largest changes in the studied parameters were observed in the cells incubated with bark ethanolic extract. We consider that the compounds from U. tomentosa extracts mainly build into the outer, hydrophilic monolayer of the erythrocyte membrane, thus protecting the erythrocytes against the adverse effects of oxidative stress.

Targeting Foam Cell Formation in Atherosclerosis: Therapeutic Potential of Natural Products

Foam cell formation and further accumulation in the subendothelial space of the vascular wall is a hallmark of atherosclerotic lesions. Targeting foam cell formation in the atherosclerotic lesions can be a promising approach to treat and prevent atherosclerosis. The formation of foam cells is determined by the balanced effects of three major interrelated biologic processes, including lipid uptake, cholesterol esterification, and cholesterol efflux. Natural products are a promising source for new lead structures. Multiple natural products and pharmaceutical agents can inhibit foam cell formation and thus exhibit antiatherosclerotic capacity by suppressing lipid uptake, cholesterol esterification, and/or promoting cholesterol ester hydrolysis and cholesterol efflux. This review summarizes recent findings on these three biologic processes and natural products with demonstrated potential to target such processes. Discussed also are potential future directions for studying the mechanisms of foam cell formation and the development of foam cell-targeted therapeutic strategies.

Microbiome and metabonomics study of quercetin for the treatment of atherosclerosis

BACKGROUND

The molecular mechanism of quercetin in the prevention and treatment of AS has been widely reported. However, the microbial and metabolic characteristics of quercetin in AS treatment are still poorly understood. In this study, we aimed to explore the gut microbial and metabolic signatures of quercetin in AS treatment and conduct an integrative analysis on its biomechanism.

METHODS

An atherosclerosis mouse model was induced by a high cholesterol diet (HCD). The duration of the quercetin treatment was 12 weeks. We measured TC, TG, HDL and LDL for plasma biochemical analysis and TNF-α and IL-6 for plasma inflammatory analysis. Haematoxylin-eosin (HE) staining was conducted to evaluate the aortic structure and atherosclerosis. Bacterial DNA, which was extracted from mouse faeces, was identified by the V3-V4 regions of the 16S rRNA for microbiological analysis. The HeatMap package of BTtools was applied to visualize the data of the microbial difference matrix according to the OTU results. Fecal metabolites were assessed through LC-MS. Multivariate data analysis was conducted on the normalized data with SIMCA-P+. Significantly different metabolites were extracted based on the Pearson correlation coefficients at the level of P<0.05. Key significantly changed metabolites were screened from the intersection between metabolic signatures of the normal-model and model-quercetin groups. To investigate the biological function of quercetin on AS, we identified the differential metabolic signatures of the model vs. quercetin groups and performed KEGG analyses via MBROLE, MetaboAnalyst database.

RESULTS

Quercetin treatment for 12 weeks significantly reduced the levels of TC (P<0.001), TG (P<0.05), HDL (P<0.001), LDL (P<0.001), TNF-α (P<0.001) and IL-6 (P<0.001) compared with the model group. HE staining indicated that quercetin could protect damaged vessels caused by HFD. Bacteroidetes, Firmicutes and Proteobacteria were dominant microbial groups in the samples. There was no significant difference between the three groups (P>0.05) at the phylum level, and the genera Phascolarctobacterium and Anaerovibrio can be regarded as the key microbiota signatures of quercetin treatment. PLS-DA results further showed that these 18 faecal metabolites (clustered in 3 groups) had significant differences between the control, model and quercetin groups throughout the 12-day treatment. According to the quantitative analysis results, 32 key metabolic signatures were screened for quercetin treatment. The main pathway in quercetin treatment is primary bile acid biosynthesis, as 3α,7α,12α,26-tetrahydroxy-5β-cholestane (C27H48O4) was defined as the most important key metabolic signature.

CONCLUSIONS

We explored the gut microbial and metabolic involvement of quercetin in AS treatment and suggest the association between AS and gut metabolic regulation.

HPLC-DAD Analysis, Antioxidant and Protective Effects of Tunisian Rhanterium suaveolens against Acetamiprid Induced Oxidative Stress on Mice Erythrocytes

The present study was performed to assess the HPLC-DAD analysis as well as antioxidant and protective effects of Tunisian Rhanterium suaveolens (Rs) against acetamiprid (ACT) induced oxidative stress on mice erythrocytes. The in vitro assays showed that the methanolic extract of Rs has an impressive antioxidant effect proved by testing the total antioxidant and scavenging activities using BCB, DPPH and ABTS assays, respectively. Moreover, qualitative and quantitative analysis using HPLC-DAD revealed the richness of Rs in polyphenols where p-Coumaric, Apigenin-7-glucoside and Ferulic acid were detected as the most abundant polyphenols. In the in vivo experiment, ACT, used as a toxicity model, was given to mice at a dose of 20 mg/kg. The latter was the origin of hemolytic anemia characterized by a significant decrease in red blood cells, hemoglobin and hematocrit levels and an increase in bilirubin, LDH, osmotic fragility, reticulocytes and white blood cells number. Characteristic erythrocyte morphological alterations were also determined as spherocytosis, schistocytosis and dacryocystitis. The oxidative status of ACT-treated mice was also altered manifested by a significant increase in MDA and GSH levels and a decrease in SOD, CAT and GPx activities. When receiving the Rs methanolic extract at a dose of 300 mg/kg, all the parameters cited above were restored in mice. These remarkable corrections could only confirm the important antioxidant effect and the noticeable protective properties that possess Rs owing to its broad range of secondary bioactive metabolites.

The Impact of O-Glycosylation on Cyanidin Interaction with RBCs and HMEC-1 Cells-Structure⁻Activity Relationships

With the aim of contributing to the knowledge about their potential therapeutic activity, we determined the biological activities of cyanidin and its selected O-glycosides in relation to erythrocytes (RBCs) and human dermal vascular endothelial cells (HMEC-1). Furthermore, on the basis of changes in the physical/functional properties of the cells, the structure–activity relationships of the compounds were determined. Concerning erythrocytes, we analyzed the antioxidant activity of the compounds and their impact on the RBCs’ shape and transmembrane potential. The compounds’ cytotoxic activity, ability to modulate apoptosis, cell cycle, and intracellular ROS generation, as well as inhibitory activity against AAPH-inducted oxidative stress, were determined in relation to HMEC-1 cells. We demonstrated that biological activity of cyanidin and its O-glycosides strongly depends on the number and type of sugar substituents, and varies depending on the extracellular environment and type of cells. The compounds are practically non-cytotoxic, and do not induce apoptosis or disturb the progression of the cell cycle. Additionally, the compounds alter the shape of RBCs, but they do not affect their transmembrane potential. They effectively protect erythrocytes against free radicals and affect intracellular reactive oxygen spices (ROS) generation under physiological and AAPH-induced oxidative stress conditions. Our results suggest a potential beneficial effect of cyanidin on the cardiovascular system.

Modulation of ERK1/2 and Akt Pathways Involved in the Neurotrophic Action of Caffeic Acid Alkyl Esters

Neurodegenerative diseases affect millions of human lives all over the world. The number of afflicted patients is rapidly growing, and disease-modifying agents are urgently needed. Caffeic acid, an important member of the hydroxycinnamic acid family of polyphenols, has considerable neurotrophic effects. We have previously shown how caffeate alkyl ester derivatives significantly promote survival and differentiation in neuronal cells. In this study, the mechanisms by which these ester derivatives exert their neurotrophic effects are examined. A series of eight caffeic acid esters with different alkyl chain lengths, ranging from methyl (CAF1) to dodecyl esters (CAF8), were synthesized and studied for their influence on neurotrophic signaling pathways. Caffeate esters did not induce tropomyosin-receptor kinase A (TrkA) phosphorylation, which was assessed by immunoblotting up to a concentration of 25 µM. NIH/3T3 cells overexpressing TrkA were generated to further examine phosphorylation of this receptor tyrosine kinase. None of the esters induced TrkA phosphorylation in these cells either. Assessment of the effect of caffeate derivatives on downstream neurotrophic pathways by immunoblotting showed that the most potent esters, decyl caffeate (CAF7) and dodecyl caffeate (CAF8) caused extracellular signal-regulated kinase (ERK1/2) and Akt serine threonine kinase phosphorylation in PC12 cells at 5 and 25 µM concentrations. In conclusion, this study shows that caffeate esters exert their neurotrophic action by modulation of ERK1/2 and Akt signaling pathways in neuronal cells, and further demonstrates the potential therapeutic implications of these derivatives for neurodegenerative diseases.

Anthocyanins in cereals: Composition and health effects

Coloured (black, purple, blue, pink, red, and brown) cereal grains have gained much attention recently due to attractive nutritional values. A major type of pigments responsible for the colours as well as the health benefits of the cereals are anthocyanins. Focusing on the recent updates, this review summarises the chemical composition of the anthocyanins in diverse cereals including maize, rice, wheat, barley, sorghum, millet, and rye. There is a great diversity in anthocyanin composition among various cereals. Special cereal genotypes with much enhanced anthocyanin content (e.g., endosperm of rice kernels rich in anthocyanins) have been developed by genetic means. The coloured cereals as potential ingredients for functional food production have been subjected to extensive research for health benefits. Both in vitro and in vivo studies on the health effects of the anthocyanins from the cereals have been summarised. The claimed health benefits include anti-oxidation, anti-cancer, glycemic and bodyweight regulation, neuroprotection, retinal protection, hypolipidemia, hepatoprotection, and anti-ageing. These health effects suggest potential uses of the cereal anthocyanins for positive human nutrition. However, clinical and human studies are needed to confirm these claimed health effects.

Antioxidant activity and Hypolipidemic effect of Ficus carica leaf and twig extracts in Triton WR-1339-induced hyperlipidemic mice

BACKGROUND/AIM: The hypolipidemic potential of both leaf and twig extracts of Ficus carica on experimental hyperlipidaemia induced by Triton WR-1339, in Swiss albino mice was investigated. In addition, the phenolic, flavonoid and anthocyanin contents of these extracts and their antioxidant activities were determined. These properties may have a synergistic effect on hyperlipidaemia. MATERIALS AND METHODS: Leaf and twig samples of F. carica were harvested and collected. The study of antioxidant activity of phenolic compounds was determined by the radical DPPH*, ABTS*+ and FRAP assays. The experimental design was carried out using acute oral toxicity study and Triton model hyperlipidaemia on Swiss albino adult male mice. The animals were observed continuously during the 14 days of the study for any physical signs of toxicity. On the 15th day, the animals were sacrificed by decapitation under anesthesia and the organs were observed for macroscopic pathological lesions. Hyperlipidaemia was induced in the mice by a single intravenous (iv) injection of Triton WR 1339 (300 mg/kg body weight), and the antihyperlipidemic effect of each extract, studied at 150 and 300 mg, was tested by gavage. After 24 hours of administration, serum from blood samples was used to estimate the various parameters of the lipid profile namely TC, TG, LDL and HDL. RESULTS: The results of the phenolic and flavonoid compounds of Ficus carica leaves and twigs varied from 12.84 to 19.78 mg gallic acid equivalents (GAE) and 5.02 to 9.72 mg EQ/g dry matter, respectively. The scavenging activity (IC50) against the radical DPPH* and ABTS*+ varied from 346.2 to 461.38 μg/mL and 288.3 to 369.01 μg/mL for twigs and leaves respectively, and from 50.82 to 54.2 μg/mL for FRAP assay. The acute toxicity study showed no mortality and clinical signs of toxicity in the tested doses. The LD50 value of extracts of twigs and leaves of Ficus carica is greater than 5000 mg/kg. The results revealed that the administration of Ficus carica (FC) leaf and twig extracts resulted in a significant (p < 0.05) decline in levels of serum triglycerides, total cholesterol, LDL-c, and VLDL-c, while the serum high-density lipoprotein cholesterol was significantly increased. The decrease rate of the lipid parameters differs significantly (p < 0.05) from the leaf and twig extracts and depends also on the administered dose. CONCLUSION: Ficus carica leaf and twig extracts may contain compounds able to lower plasma lipid concentrations, could contribute significantly to the total antioxidant properties and be beneficial in the treatment of hyperlipidaemia.

Design, Synthesis and Biological Evaluation of Novel Primaquine-Cinnamic Acid Conjugates of the Amide and Acylsemicarbazide Type

In this paper design and synthesis of a scaffold comprising primaquine (PQ) motif and cinnamic acid derivatives (CADs) bound directly (compounds 3a-k) or via a spacer (compounds 7a-k) are reported. In the first series of compounds, PQ and various CADs were connected by amide bonds and in the second series by acylsemicarbazide functional groups built from the PQ amino group, CONHNH spacer and the carbonyl group originating from the CADs. PQ-CAD amides 3a-k were prepared by a simple one-step condensation reaction of PQ with a series of CAD chlorides (method A) or benzotriazolides 2 (method B). The synthesis of acylsemicarbazides 7a-k included activation of PQ with benzotriazole, preparation of PQ-semicarbazide 6 and its condensation with CAD chlorides 4. All synthesized PQ-CAD conjugates were evaluated for their anticancer, antiviral and antioxidative activities. Almost all compounds from series 3 were selective towards the MCF-7 cell line and active at micromolar concentrations. The o-fluoro derivative 3h showed high activity against HeLa, MCF-7 and in particular against the SW 620 cell line, while acylsemicarbazide 7f with a benzodioxole ring and 7c, 7g and especially 7j with methoxy-, chloro- or trifluoromethyl-substituents in the para position showed high selectivity and high inhibitory activity against MCF-7 cell line at micromolar (7c, 7f, 7g) and nanomolar (7j) levels. Acylsemicarbazide derivatives with trifluoromethyl group(s) 7i, 7j and 7k showed specific activity against human coronavirus (229E) at concentrations which did not alter the normal cell morphology. The same compounds exerted the most potent reducing activity in the DPPH test, together with 7d and 7g, while methoxy (compounds 7c-e), benzodioxole (7f), p-Cl (7g) and m-CF₃ (7i) acylsemicarbazides and amide 3f presented the highest LP inhibition (83%-89%). The dimethoxy derivative 7d was the most potent LOX inhibitor (IC50 = 10 μΜ). The performed biological tests gave evidence of acylsemicarbazide functional group as superior binding group in PQ-CAD conjugates.

Cyanidin-3-O-glucoside: Physical-Chemistry, Foodomics and Health Effects

Anthocyanins (ACNs) are plant secondary metabolites from the flavonoid family. Red to blue fruits are major dietary sources of ACNs (up to 1 g/100 g FW), being cyanidin-3-O-glucoside (Cy3G) one of the most widely distributed. Cy3G confers a red hue to fruits, but its content in raspberries and strawberries is low. It has a good radical scavenging capacity (RSC) against superoxide but not hydroxyl radicals, and its oxidative potential is pH-dependent (58 mV/pH unit). After intake, Cy3G can be metabolized (phases I, II) by oral epithelial cells, absorbed by the gastric epithelium (1%-10%) and it is gut-transformed (phase II &amp; microbial metabolism), reaching the bloodstream (<1%) and urine (about 0.02%) in low amounts. In humans and Caco-2 cells, Cy3G's major metabolites are protocatechuic acid and phloroglucinaldehyde which are also subjected to entero-hepatic recycling, although caffeic acid and peonidin-3-glucoside seem to be strictly produced in the large bowel and renal tissues. Solid evidence supports Cy3G's bioactivity as DNA-RSC, gastro protective, anti-inflammatory, anti-thrombotic chemo-preventive and as an epigenetic factor, exerting protection against Helicobacter pylori infection, age-related diseases, type 2 diabetes, cardiovascular disease, metabolic syndrome and oral cancer. Most relevant mechanisms include RSC, epigenetic action, competitive protein-binding and enzyme inhibition. These and other novel aspects on Cy3G's physical-chemistry, foodomics, and health effects are discussed.

Effect of biologically active substances present in water extracts of white mustard and coriander on antioxidant status and lipid peroxidation of mouse C2C12 skeletal muscle cells

Coriander and white mustard, an annual plants originated in the Mediterranean region, have been cultivated and used as spices for a long time. Recent studies have shown that they may constitute a potential source of phenolic compounds. The aim of this study was to evaluate the content of polyphenols in coriander and white mustard water extracts and to investigate their antioxidant activity in C2C12 mouse skeletal muscle cells, which serve as a good model of cells with intensive metabolism. HPLC analysis showed that polyphenols were able to permeate from the water extracts of studied plants into the undifferentiated myoblasts as well as myocytes undergoing differentiation, increasing the concentration of reduced glutathione and upregulating glutathione reductase and peroxidase activity. White mustard and coriander extracts also decreased the levels of oxysterols and sum of tiobarbituric acid reactive substances (TBARS) in both: myoblasts and differentiating myocytes, demonstrating protective effect on cell membranes. The obtained results indicate that polyphenols synthesized by both herbs may have beneficial effects on muscle tissue.

Modification of the properties of biological membrane and its protection against oxidation by Actinidia arguta leaf extract

The aim of the study was to determine the polyphenol composition and biological activity of an extract from the leaves of kiwi. Antioxidant and hemolytic activity of the extract were examined, as well as its effect on the physical properties of the erythrocyte membrane such as osmotic resistance, membrane fluidity, and packing order of its hydrophilic area. Antioxidant activity of the extract was determined in relation to the erythrocyte membrane oxidized with free radicals induced by UVB and UVC radiation and the compound AAPH. Chromatographic, spectrophotometric and fluorimetric methods were applied in the research. The obtained results showed that kiwi leaves are a rich source of polyphenolic substances, mainly catechins and their dimers, which do not induce red blood cell hemolysis but make them stronger and more resistant to changes in medium tonicity. Substances contained in the extract effectively protect erythrocyte membranes against oxidation induced by physicochemical factors, the effectiveness of the protection depending on the concentration and type of free radical inducer. In addition, the study showed that the kiwi extract increases fluidity of the erythrocyte membrane and causes an increase in packing disorder in the hydrophilic membrane area. The changes seem to be due to the presence of polyphenolic substances in the extract, mainly in the region of the polar heads of lipids, where they can form a barrier protecting the membrane against diffusion of free radicals to the membrane interior. The effects of the extract evidenced by the present research, in particular protection of the biological membrane against free radicals induced by physicochemical agents, make it a potential valuable food additive, to enrich it with polyphenolic compounds that inhibit lipid oxidation in food exposed to UVB radiation. Supplementing the organism with substances contained in kiwi leaves is expected to provide protection against many diseases that develop as a result of oxidative stress.