Antioxidant activities of different colored sweet bell peppers (Capsicum annuum L.)

Luteolin Attenuates IL-1β-Induced THP-1 Adhesion to ARPE-19 Cells via Suppression of NF-κB and MAPK Pathways

Cytokine-induced endothelial dysfunction leads to inflammation and vascular adhesion molecule production in retinal pigment epithelium (RPE) cells. Inflammation is a critical mediator in retinal degeneration (RD) diseases, including age-related macular degeneration (AMD), and RD progression may be prevented through anti-inflammatory activity in RPE cells. The flavonoid polyphenol luteolin (LU) has anti-inflammatory and antidiabetes activities, but its effects regarding retinal protection remain unknown. Here, we examined the ability of luteolin to alleviate markers of inflammation related to RD in cytokine-primed APPE-19 cells. We found that luteolin decreased the levels of interleukin- (IL-) 6, IL-8, soluble intercellular adhesion molecule-1 (sICAM-1), and monocyte chemoattractant protein-1 (MCP-1) and attenuated adherence of the human monocytic leukemia cell line THP-1 to IL-1β-stimulated ARPE-19 cells. Luteolin also increased anti-inflammatory protein heme oxygenase-1 (HO-1) levels. Interestingly, luteolin induced protein kinase B (AKT) phosphorylation, thus inhibiting nuclear factor- (NF-) κB transfer from cytoplasm into the nucleus and suppressing mitogen-activated protein kinase (MAPK) inflammatory pathways. Furthermore, cotreatment with MAPK inhibitors and luteolin decreased inflammatory cytokine and chemokine levels, and further suppressed THP-1 adhesion. Overall, these results provide evidence that luteolin protects ARPE-19 cells from IL-1β-stimulated increases of IL-6, IL-8, sICAM-1, and MCP-1 production by blocking the activation of MAPK and NF-κB signaling pathways, thus ameliorating the inflammatory response.

Phytochemical Assessment of Native Ecuadorian Peppers (Capsicum spp.) and Correlation Analysis to Fruit Phenomics

In this work, the impact of pepper (Capsicum spp.) fruits morphology on their composition for health-promoting compounds was investigated. For that purpose, pepper accessions from Ecuador, one of the hotspots in Capsicum's origin, were analyzed for ascorbic acid, polyphenols, capsaicinoids, and prevention of cholesterol oxidation. Plant and fruit phenomics were assessed with conventional descriptors and Tomato Analyzer digital traits. Significant differences among accessions and species revealed a large diversity within the collection. The Capsicum frutescens group displayed the highest levels of capsaicinoids, whereas the polyphenols shortly varied among the five domesticated species. Capsicum pubescens exhibited the lowest content of ascorbic acid. The conventional descriptors describing the magnitude of plants and fruits, as well as digital attributes under the categories of size, shape index, and latitudinal section, mostly explained the variance among Capsicum groups. Correlation test revealed that phytochemical components were negatively correlated with the morphometric fruit attributes, suggesting that huge fruits contained lower amounts of nutraceutical compounds. Multivariate analysis showed that parameters related to fruit size, shape, and nutraceutical composition primarily contribute to the arrangement of pepper accessions. Such results suggested that those traits have been subjected to higher selection pressures imposed by humans.

Cross-Species Comparison of Fruit-Metabolomics to Elucidate Metabolic Regulation of Fruit Polyphenolics Among Solanaceous Crops

Many solanaceous crops are an important part of the human daily diet. Fruit polyphenolics are plant specialized metabolites that are recognized for their human health benefits and their defensive role against plant abiotic and biotic stressors. Flavonoids and chlorogenates are the major polyphenolic compounds found in solanaceous fruits that vary in quantity, physiological function, and structural diversity among and within plant species. Despite their biological significance, the elucidation of metabolic shifts of polyphenols during fruit ripening in different fruit tissues, has not yet been well-characterized in solanaceous crops, especially at a cross-species and cross-cultivar level. Here, we performed a cross-species comparison of fruit-metabolomics to elucidate the metabolic regulation of fruit polyphenolics from three representative crops of Solanaceae (tomato, eggplant, and pepper), and a cross-cultivar comparison among different pepper cultivars (Capsicum annuum cv.) using liquid chromatography-mass spectrometry (LC-MS). We observed a metabolic trade-off between hydroxycinnamates and flavonoids in pungent pepper and anthocyanin-type pepper cultivars and identified metabolic signatures of fruit polyphenolics in each species from each different tissue-type and fruit ripening stage. Our results provide additional information for metabolomics-assisted crop improvement of solanaceous fruits towards their improved nutritive properties and enhanced stress tolerance.

A DNA-encoded library for the identification of natural product binders that modulate poly (ADP-ribose) polymerase 1, a validated anti-cancer target

Natural products have been an invaluable source of drug discovery, but their targets remain largely unknown. Natural products enriched DNA-encoded chemical libraries (nDELs) empower the researchers to rapidly and economically screen numerous natural products against various protein targets, and therefore promote the elucidation of the molecular mechanisms. In this work, we used poly (ADP-ribose) polymerase 1 (PARP1), as an example to explore the usage of nDEL for the functional natural products selection. We used late-stage modification approach to label three positive binders with unique DNA barcodes, whose dissociation constants range from sub-micromolar to micromolar. The selection criterion was set up according to the enrichment of these controls. Five natural products selected by this criterion directly bind to PARP1 in SPR, among which luteolin exhibits the highest inhibitory activity against PARP1. Moreover, luteolin selectively induces accumulation of DNA double-strand breaks and G2/M phase arrest in BRCA-deficient cells. All the findings from these investigations on luteolin support that PARP1 inhibition is one of the mechanisms for its anti-cancer activity.

Comparative Analysis of Commercial Chinese Bean Sauce (Chunjang) from Korea and China Based on Antioxidant Activity

In this study, the antioxidant effects of seven types of commercial Chunjang from China (C1∼3) and Korea (K1∼4) were compared for their ability to protect against H₂O₂-induced DNA damage. Outputs included total phenolic content (TPC), 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity (DPPH RSA), oxygen radical absorbance capacity (ORAC), total radical trapping antioxidant potential (TRAP), and comet assays. TPC was the highest in C3 (1,250.8 mg gallic acid equivalent/100 g). C1 exhibited a significantly higher DPPH RSA IC₅₀ (7.5 mg/mL) and ORAC concentration (8.22 μM Trolox equivalent) compared with all other samples, and C1 and K1 exhibited the highest TRAPs. H₂O₂-induced DNA damage was effectively protected by Chunjang, with a higher observed in C2, C3, and K1 (24.2∼25.3 μg/mL) compared with the other samples (28.3∼30.0 μg/mL). Our results showed that commercial Chunjang contains polyphenol and antioxidant activities. The differences between the samples might be attributed to different origins, materials, and processing methods.

Influence of Postharvest Temperatures on Carotenoid Biosynthesis and Phytochemicals in Mature Green Chili (Capsicum annuum L.)

An intense red color appearance in hot chili is what industry commonly demands. The harvested mature green “Takanotsume” chili, a popular cultivar in Japan, incubated at 20 and 30 °C is investigated. At 30 °C, the chili rapidly degraded chlorophylls and obtained an intense red color, but presented an orange–red color at 20 °C. The sample showed higher carotenoid accumulations at 30 °C, along with significantly upregulated carotenoid biosynthesis-related genes—phytoene synthase (Psy), lycopene-β-cyclase (Lcyb), β-carotene hydroxylase (CrtZ), and capsanthin/capsorubin synthase (Ccs)—during the experiment. While the expression of the Ccs gene was reduced, there was a 5.5-fold upregulation of the Psy gene at the end of incubation. At 20 °C, the Psy gene was downregulated. These observations suggest that the expression of individual genes is temperature-dependent, and these would affect specific carotenoid compounds. The antioxidant capacity (2,2-diphenyl-1-picrylhydrazyl; DPPH and ferric-reducing antioxidant power; FRAP) values had no difference between temperatures; the higher content of total phenolics and vitamin C presented in the chili at 30 °C probably corresponds to the advanced ripening process. Thus, 30 °C is the recommended incubation temperature for mature green chili to achieve the industry-demanded intense red color and high accumulation of phytochemicals.

Flavored functional drinking yogurt (Doogh) formulated with Lactobacillus plantarum LS5, cress seed gum, and coriander leaves extract

The effects of coriander extract (CE) and cress seed gum (CSG) on viability of Lactobacillus plantarum LS5 and physicochemical properties of drinking yogurt (Doogh) were evaluated. The CE contained 18 mg GAE/g and was shown by the DPPH radical assay to have remarkable antioxidant activity. The CE was added at concentrations of 0%, 0.05%, 0.1%, and 0.25%, and the levels of added CSG were 0%, 0.1%, 0.25%, and 0.5%. Doogh samples were analyzed after 1, 2, and 3 weeks of storage at 4°C. By increasing the amounts of CSG, the viscosity of the Doogh samples was increased and phase separation was reduced significantly (p < .05). The results also showed that by increasing the levels of CSG to 0.5%, L. plantarum count increased significantly (p < .05). Doogh sample containing 0.05% CE and 0.5% CSG gained the highest probiotic count, overall acceptability score, and lowest lipid oxidation and phase separation in comparison with the other samples.

Color Development and Phytochemical Changes in Mature Green Chili (Capsicum annuum L.) Exposed to Red and Blue Light-Emitting Diodes

Exposure of mature green "Takanotsume" chili fruit to blue and red light-emitting diodes (LEDs) was investigated. The red LED accelerated the red color development of chili as indicated by higher a* and chroma values, as well as lower hue angle and total chlorophyll compared to the blue LED and darkness (control). These were linked to increases in β-carotene, free-capsanthin, and total carotenoids. The carotenoid biosynthesis-related genes, lycopene-β-cyclase (Lcyb), β-carotene hydroxylase (CrtZ), and capsanthin/capsolubin synthase (Ccs), were up-regulated by the red LED after 2 days of the experiment. The blue LED was more effective in increasing the expression of the phytoene synthase (Psy) gene at day 1 of experiment. The total phenolic, vitamin C content, and antioxidant capacity were also higher in the blue LED-treated chili. Results suggest that the responses of each carotenoid-related gene to the light wavelengths and the accumulation of phytochemicals are specific characteristics of this chili cultivar.

Effects of flavonoids on tongue squamous cell carcinoma

Squamous cell carcinoma (SCC) of the tongue is associated with tobacco use, alcohol abuse, and human papillomavirus (HPV) infections. While clinical outcomes have recently improved for HPV-positive patients in general, 50% of patients suffering from tongue cancer die within 5 years of being diagnosed. Flavonoids are secondary plant metabolites with a wide range of biological activities including antioxidant, anti-inflammatory, and anticancer activities. Flavonoids have generated high interest as therapeutic agents owing to their low toxicity and their effects on a large variety of cancer cell types. In this literature review, we evaluate the actions of flavonoids on SCC of the tongue demonstrated in both in vivo and in vitro models.

Bioactive Compounds, Antioxidant Activity and Inhibition of Key Enzymes Relevant to Alzheimer's Disease from Sweet Pepper (Capsicum annuum) Extracts

Sweet pepper is a non-pungent chili of the Capsicum annuum species and is an important ingredient in daily diets due to its characteristics such as pungency, aromas, and flavors. Sweet pepper is a rich source of bioactive compounds such as phenols, carotenoids, and flavonoids, which can promote potential health benefits against various non-communicable diseases. However, research focused on anti-Alzheimer’s disease (AD) properties of sweet peppers is limited. Thus, this study aimed investigate bioactive compounds (flavonoids, phenolic acids, and carotenoids), antioxidant activity and anti-AD properties of four colored sweet peppers (green, red, orange, and yellow) via their abilities to inhibit key enzymes relevant to AD [acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and β-secretase (BACE1)]. Extraction solvents [hexane, ethyl acetate, and 70% (v/v) aqueous ethanol] were also investigated. Results suggested that yellow sweet pepper have the highest content of flavonoids, while green sweet pepper have the highest contents of phenolic acids and red sweet peppers have the highest content of carotenoids. In terms of anti-AD properties, green sweet peppers exhibited the highest antioxidant, anti-BChE, and anti-BACE1 activities; however, yellow sweet pepper extract exhibited the highest amounts of AChE inhibition. Bioactive compounds in sweet red peppers may therefore have anti-AD properties, and may be useful for AD prevention.

Lysozyme-luteolin binding: molecular insights into the complexation process and the inhibitory effects of luteolin towards protein modification

In the proposed work, the complexation of bioactive flavonoid luteolin with hen egg white lysozyme (HEWL) along with its inhibitory influence on HEWL modification has been explored with the help of multi-spectroscopic and computational methods. The binding affinity has been observed to be moderate in nature (in the order of 10⁴ M^-1) and the static quenching mechanism was found to be involved in the fluorescence quenching process. The binding constant (K_b) shows a progressive increase with the increase in temperature from (4.075 ± 0.046 × 10⁴ M^-1) at 293 K to (6.962 ± 0.024 × 10⁴ M^-1) at 313 K under experimental conditions. Spectroscopic measurements along with molecular docking calculations suggest that Trp62 is involved in the binding site of luteolin within the geometry of HEWL. The positive changes in enthalpy (ΔH = +19.99 ± 0.65 kJ mol^-1) as well as entropy (ΔS = +156.28 ± 2.00 J K^-1 mol^-1) are indicative of the presence of hydrophobic forces that stabilize the HEWL-luteolin complex. The micro-environment around the Trp residues showed an increase in hydrophobicity as indicated by synchronous fluorescence (SFS), three dimensional fluorescence (3D) and red edge excitation (REES) studies. The % α-helix of HEWL showed a marked reduction upon binding with luteolin as indicated by circular dichroism (CD) and Fourier-transform infrared spectroscopy (FTIR) studies. Moreover, luteolin is situated at a distance of 4.275 ± 0.004 nm from the binding site as indicated by FRET theory, and the rate of energy transfer k_ET (0.063 ± 0.004 ns^-1) has been observed to be faster than the donor decay rate (1/τ_D = 0.606 ns^-1), which is indicative of the non-radiative energy transfer during complexation. Leaving aside the binding study, luteolin showed promising inhibitory effects towards the d-ribose mediated glycation of HEWL as well as towards HEWL fibrillation as studied by fluorescence emission and imaging studies. Excellent correlation with the experimental observations as well as precise location and dynamics of luteolin within the binding site has been obtained from molecular docking and molecular dynamics simulation studies.

Functionality-Independent DNA Encoding of Complex Natural Products

DNA encoded chemical libraries (DELs) link the powers of genetics and chemical synthesis via combinatorial optimization. Through combinatorial chemistry, DELs can grow to the unprecedented size of billions to trillions. To take full advantage of the DEL approach, linking the power of genetics directly to chemical structures would offer even greater diversity in a finite chemical world. Natural products have evolved an incredible structural diversity along with their biological evolution. Herein, we used traditional Chinese medicines (TCMs) as examples in a late-stage modification toolbox approach to annotate these complex organic compounds with amplifiable DNA barcodes, which could be easily incorporated into a DEL. The method of end-products labeling also generates a cluster of isomers with a single DNA tag at different sites. These isomers provide an additional spatial diversity for multiple accessible pockets of targeted proteins. Notably, a novel PARP1 inhibitor from TCM has been identified from the natural products enriched DEL (nDEL).

GRP78/BIP/HSPA5 as a Therapeutic Target in Models of Parkinson's Disease: A Mini Review

Parkinson's disease (PD) is a common neurodegenerative disorder characterized by selective loss of dopamine neurons in the substantia nigra pars compacta of the midbrain. Reports from postmortem studies in the human PD brain, and experimental PD models reveal that endoplasmic reticulum (ER) stress is implicated in the pathogenesis of PD. In times of stress, the unfolded or misfolded proteins overload the folding capacity of the ER to induce a condition generally known as ER stress. During ER stress, cells activate the unfolded protein response (UPR) to handle increasing amounts of abnormal proteins, and recent evidence has demonstrated the activation of the ER chaperone GRP78/BiP (78 kDa glucose-regulated protein/binding immunoglobulin protein), which is important for proper folding of newly synthesized and partly folded proteins to maintain protein homeostasis. Although the activation of this protein is essential for the initiation of the UPR in PD, there are inconsistent reports on its expression in various PD models. Consequently, this review article aims to summarize current knowledge on neuroprotective agents targeting the expression of GRP78/BiP in the regulation of ER stress in experimental PD models.

Supercritical Fluid Extraction of Carotenoids from Vegetable Waste Matrices

The aim of this work was to evaluate a previously-developed model on supercritical fluid extraction (SFE) for carotenoid recovery from carrot peels on various carotenoid-rich fruit and vegetable wastes. To this end, 15 matrices, including flesh and peels of sweet potato, tomato, apricot, pumpkin and peach, as well as flesh and wastes of green, yellow and red peppers, were submitted to SFE under optimised conditions (59 °C, 350 bar, 15 g/min CO₂, 15.5% (v/v) ethanol as co-solvent, 30 min of extraction time). The obtained extracts were characterised for their total carotenoid content, antioxidant activity and total carotenoid recovery (TCR). TCR values were greater than 90% w/w for most samples, with β-carotene being the most successfully extracted compound (TCRs 88–100% w/w). More polar carotenoids, such as lutein and lycopene, exhibited lower TCRs. A comparison with literature data suggested that carotenoid extraction is partially dependent on the composition of vegetable matrices, specifically on polysaccharide and moisture content. The results indicated that the optimised SFE conditions can be used as a general model for carotenoid extraction from various fruit and vegetable matrices and as a viable method for adding value to these waste streams by generating carotenoid-rich extracts.

Genetic diversity analysis of selected Capsicum annuum genotypes based on morphophysiological, yield characteristics and their biochemical properties

BACKGROUND

Assessment of the different desirable characters among chili genotypes has expanded the effective selection for crop improvement. Identification of genetically superior parents is important in assortment of the best parents to develop new chili hybrids.

RESULTS

This study was done to assess the hereditary assorted variety of selected genotypes of Capsicum annuum based on their morphophysiological and yield traits in two planting seasons. The biochemical properties, capsaicinoid content (capsaicin and dihydrocapsaicin), total phenolics content and antioxidant action determination of unripe and ripe chili pepper fruits were carried out in dry fruits. AVPP9813 and Kulai 907 were observed to have high fruit yields, with 541.39 and 502.64 g per plant, respectively. The most increased genotypic coefficient of variation (GCV) and phenotypic coefficient of variation (PCV) were shown by the fruit number per plant (49.71% and 66.04%, respectively). High heritability was observed in yield characters viz-à-viz fruit weight, length and girth and indicated high genetic advance. Eight groups were obtained from the cluster analysis. For the biochemical analysis, the capsaicinoid content and total phenolic content were high in Chili Bangi 3 at unripe and ripe fruit stages, while for antioxidant activity SDP203 was the highest in ripe dry fruit.

CONCLUSION

Higher GCV and PCV, combined with moderate to high heritability and high hereditary progress, were seen in number of fruit per plant, fruit yield per plant and fruit weight per fruit. These findings are beneficial for chili pepper breeders to select desirable quantitative characters in C. annuum in their breeding program. © 2018 Society of Chemical Industry.

Polyphenols and carotenoids in pickled bell pepper from organic and conventional production

Sweet bell pepper is a perfect source of flavonoids and carotenoids. Some experiments indicated that fresh organic vegetables contained more of these bioactive compounds in comparison to the conventional ones. It could be expected that pickled organic vegetables also contain more antioxidant compounds. The aim of this study was therefore to analyse and to compare the concentration of bioactive compounds in organic vs. conventional pickled bell pepper. Two cultivars of sweet red pepper (Roberta and Berceo) from organic and conventional cultivation were used in the experiment. The content of dry matter, polyphenols and carotenoids in fruit has been determined. The conventional pickled bell pepper fruits appeared to be richer in phenolic acids, while organic samples contained significantly more flavonoids, including myricetin, quercetin, kaempferol, apigenin, and carotenoids such as beta-carotene, alpha-carotene, capsorubin, cryptoxanthin and cryptoflavin in comparison to the conventional ones.

Potential Phytopharmacy and Food Applications of Capsicum spp.: A Comprehensive Review

Capsicum genus (Solanaceae) is native to the Americas. Today, it is an important agricultural crop cultivated around the world, not only due to its economic importance, but also for the nutritional value of the fruits. Among their phytochemical constituents, capsaicinoids are characteristic and responsible of the pungency of sharp-tasting cultivars. Moreover, Capsicum and capsaicinoids (mainly, capsaicin) have been largely studied because of their health benefits. Thus, this study reviews the scientific knowledge about Capsicum spp. and their phytochemicals against cancer, diabetes, gastrointestinal diseases, pain, and metabolic syndrome, as well as their antioxidant and antimicrobial activity. These bioactivities can be the basis of the formulation of functional ingredients and natural preservatives containing Capsicum extracts or isolated compounds.

Luteolin-mediated Kim-1/NF-kB/Nrf2 signaling pathways protects sodium fluoride-induced hypertension and cardiovascular complications

The use of sodium fluoride (NaF) as a major ingredient for tooth paste, mouth wash, and mouth rinse has become inevitable in our day-to-day life. However, flavonoids such as Luteolin might be of great value in the prevention of toxicity associated with accidental or inevitable ingestion of NaF. In the study, 40 male Wistar albino rats were randomly divided into four groups with 10 rats in a group. Group A was the control group and received normal saline, Group B was exposed to NaF at 300 ppm (300 mg/L) in drinking water daily for a week, Groups C and D were exposed to 300 ppm (300 mg/L) of NaF and coadministered with Luteolin orally daily at a dosage of 100 mg/kg and 200 mg/kg for the same time point. Our results indicated that NaF caused significant increases in systolic blood pressure, diastolic blood pressure, mean arterial pressure, malondialdehyde, protein carbonyl, myeloperoxidase, advanced oxidative protein products, together with significant reductions in glutathione peroxidase, superoxide dismutase, catalase, glutathione reductase, reduced glutathione, and nitric oxide (NO) bioavailability. The electrocardiogram results showed that NaF alone caused significant prolongation of QT and QTc intervals. Immunohistochemistry revealed that NaF caused increase expressions of Kidney injury marker 1 (Kim-1), nuclear factor kappa bet (NF-κB), nuclear factor erythroid 2-related factors 2 (Nrf2), and cardiac troponin I (CTnI). Together, Luteolin coadministration with NaF improved NO bioavailability, reduced high blood pressure, markers of oxidative stress, reversed prolongation of QT and QTc intervals, and lowered the expressions of Kim-1, NF-κB, and CTnI. © 2018 BioFactors, 44(6):518-531, 2018.

Occurrence of variable levels of health-promoting fruit compounds in horn-shaped Italian sweet pepper varieties assessed by a comprehensive approach

BACKGROUND

Cultivated pepper is a rich source of diverse bioactive compounds with potential properties related to the prevention of major degenerative and proliferative diseases. In the present study, 15 sweet pepper varieties, highly appreciated on the Italian market, were assessed for variation in the content of ascorbic acid, isoprenoids and flavonoids, as well as morpho-agronomic performances and molecular diversity.

RESULTS

The collection under study showed a wide variability for all traits considered. Traditional cultivars, although less productive, were characterized by a high content of β-carotene and ascorbic acid, reaching maximum concentrations of 230.5 mg kg^-1 fresh weight (fw) and 2750 mg kg^-1 fw, respectively. Strong correlations were demonstrated between neoxanthin and luteolins. Fruit weight was positively correlated with α-tocopherol content and negatively correlated with luteolins content. The genotyping by sequencing platform allowed the identification of 1833 single nucleotide polymorphism, which better defined the relationships among cultivars, based on provenance and improvement rate.

CONCLUSIONS

The present study provides an overview of the variability in the expression of fruit nutritional traits in a collection of horn-shaped pepper cultivars, integrating agronomic and molecular data. The impact for breeding and consumers is discussed. © 2017 Society of Chemical Industry.

Bioactive compounds from orange epicarp to enrich fish burgers

BACKGROUND

The orange industry produces considerable amounts of by-products, traditionally used for animal feed or fuel production. Most of these by-products could be used as functional ingredients. To assess the potential food application of orange epicarp, different percentages of micro-encapsulated orange extract were added to fresh fish burgers. Then, an in vitro digestion was also carried out, before and after micro-encapsulation, to measure the bio-accessibility of the active compounds.

RESULTS

A significant increase of bio-accessibility of bioactive compounds has been observed in the orange epicarp extract after micro-encapsulation by spray-drying. From the sensory point of view, the fish sample enriched with 50 g kg^-1 micro-encapsulated extract was the most comparable to the control burger, even if it showed a higher phenolic, flavonoid and carotenoid bio-accessibility.

CONCLUSION

Orange epicarp may be used as a food additive to enhance the health content of food products. The micro-encapsulation is a valid technique to protect the bioactive compounds and increase their bio-accessibility. © 2017 Society of Chemical Industry.

Whole Genome Resequencing of Capsicum baccatum and Capsicum annuum to Discover Single Nucleotide Polymorphism Related to Powdery Mildew Resistance

The present study deals with genome wide identification of single-nucleotide polymorphism (SNP) markers related to powdery mildew (PM) resistance in two pepper varieties. Capsicum baccatum (PRH1- a PM resistant line) and Capsicum annuum (Saengryeg- a PM susceptible line), were resequenced to develop SNP markers. A total of 6,213,009 and 6,840,889 SNPs for PRH1 and Saengryeg respectively have been discovered. Among the SNPs, majority were classified as homozygous type SNPs, particularly in the resistant line. Moreover, the SNPs were differentially distributed among the chromosomes in both the resistant and susceptible lines. In total, 4,887,031 polymorphic SNP loci were identified between the two lines and 306,871 high-resolution melting (HRM) marker primer sets were designed. In order to understand the SNPs associated with the vital genes involved in diseases resistance and stress associated processes, chromosome-wise gene ontology analysis was performed. The results revealed the occurrence that SNPs related to diseases resistance genes were predominantly distributed in chromosome 4. In addition, 6281 SNPs associated with 46 resistance genes were identified. Among the lines, PRH1 consisted of maximum number of polymorphic SNPs related to NBS-LRR genes. The SNP markers were validated using HRM assay in 45 F4 populations and correlated with the phenotypic disease index.

Metabolite Profiling of Peppers of Various Colors Reveals Relationships Between Tocopherol, Carotenoid, and Phytosterol Content

Peppers are widely consumed in Korea; the varietal development of peppers with increased content of beneficial plant metabolites is, therefore, of considerable interest. This requires a comprehensive understanding of the metabolic profile of pepper plants and the factors affecting this profile. To this end, we determined the content of various metabolites, such as hydrophilic and lipophilic compounds, phenolic acids, carotenoids, and capsaicinoids in peppers of various colors (green, red, pale green, and violet peppers) and in a high-pungency (green) pepper. We also performed principal component analysis (PCA), Pearson's correlation analysis, and hierarchical clustering analysis (HCA) to determine the relationships among these metabolites in peppers. PCA results indicated no significant variances among the 3 sample replicates. The HCA showed correlations between the metabolites resulting from common or closely linked biosynthesis pathways. Our results showed that carotenoids correlated positively with tocopherols and negatively with phytosterols; our findings also indicated a close relationship between the methylerythritol 4-phosphate and mevalonic acid biosynthesis pathways, providing evidence in favor of an earlier hypothesis regarding crosstalk across the chloroplast membrane. We, thus, demonstrate that metabolic profiling combined with multivariate analysis is a useful tool for analyzing metabolic networks.

PRACTICAL APPLICATION

A total of 71 metabolites were measured in 5 peppers of different colors. The metabolic profiling with multivariate analysis revealed that tocopherol content had a positive correlation with the carotenoid content and a negative correlation with the phytosterol content. The results of this study may help in breeding programs to produce new germplasm with enhanced nutritional quality.

Antioxidant Activity of Spices and Their Impact on Human Health: A Review

Antioxidants are substances that prevent oxidation of other compounds or neutralize free radicals. Spices and herbs are rich sources of antioxidants. They have been used in food and beverages to enhance flavor, aroma and color. Due to their excellent antioxidant activity, spices and herbs have also been used to treat some diseases. In this review article, the chemical composition and antioxidant activity of spices and culinary herbs are presented. The content of flavonoids and total polyphenols in different spices and herbs are summarized. The applications of spices and their impacts on human health are briefly described. The extraction and analytical methods for determination of antioxidant capacity are concisely reviewed.

Effect of Different Elicitors and Preharvest Day Application on the Content of Phytochemicals and Antioxidant Activity of Butterhead Lettuce (Lactuca sativa var. capitata) Produced under Hydroponic Conditions

The effect of four elicitors on phytochemical content in two varieties of lettuce was evaluated. The best preharvest day for application of each elicitor was chosen. Solutions of arachidonic acid (AA), salicylic acid (SA), methyl jasmonate (MJ), and Harpin protein (HP) were applied by foliar aspersion on lettuce leaves while cultivating under hydroponic conditions. Application of elicitors was done at 15, 7, 5, 3, or 1 day before harvest. Green lettuce showed the highest increase in phytochemical content when elicitors (AA, SA, and HP) were applied on day 7 before harvest. Similarly, antioxidant activity rose in all treatments on day 7. In red lettuce, the highest content of bioactive molecules occurred in samples treated on day 15. AA, SA, and HP were the elicitors with the highest effect on phytochemical content for both varieties, mainly on polyphenol content. Antioxidant activity also increased in response to elicitation. HPLC-MS showed an increase in the content of phenolic acids in green and red lettuce, especially after elicitation with SA, suggesting activation of the caffeic acid pathway due to elicitation.

In vivo and in vitro evaluation for nutraceutical purposes of capsaicin, capsanthin, lutein and four pepper varieties

The purpose of this study is to determine the nutraceutic potential of different Capsicum sp, capsaicin, capsanthin and lutein and provide data in order to clarify the conflicting results obtained for capsaicin by different authors. To achieve these objectives, in vivo (geno/antigenotoxicity and lifespan assays in the animal model Drosophila) and in vitro (cytotoxicity and DNA-fragmentation assays in HL60 promyelocytic cell line) assays were carried out. Results showed that i) none of the tested substances were genotoxic except green hot pepper and capsaicin at the highest tested concentration (5 mg/mL and 11.5 μM respectively), ii) all tested substances except green hot pepper are antimutagenic against H₂O₂-induced damage, iii) only red sweet pepper significantly extend the lifespan and healthspan of D. melanogaster at 1.25 and 2.5 mg/mL, iv) all pepper varieties induce dose-depended cytotoxic effect in HL60 cells with different IC₅₀, and v) all pepper varieties and capsaicin exerted proapoptotic effect on HL60 cells.

IN CONCLUSION

(i) sweet peppers could be suggested as nutraceutical food, (ii) hot peppers should be moderately consumed, and (iii) supplementary studies are necessary to clarify the synergic effect of the carotenoids and capsaicinoids in the hot pepper food matrix.

Molecular targets of luteolin in cancer

Many food-derived phytochemical compounds and their derivatives represent a cornucopia of new anticancer compounds. Despite extensive study of luteolin, the literature has no information on the exact mechanisms or molecular targets through which it deters cancer progression. This review discusses existing data on luteolin's anticancer activities and then offers possible explanations for and molecular targets of its cancer-preventive action. Luteolin prevents tumor development largely by inactivating several signals and transcription pathways essential for cancer cells. This review also offers insights into the molecular mechanisms and targets through which luteolin either prevents cancer or mediates cancer cell death.

Vitamin Variation in Capsicum Spp. Provides Opportunities to Improve Nutritional Value of Human Diets

Chile peppers, native to the Americas, have spread around the world and have been integrated into the diets of many cultures. Much like their heat content, nutritional content can vary dramatically between different pepper types. In this study, a diverse set of chile pepper types were examined for nutrient content. Some pepper types were found to have high levels of vitamin A, vitamin C, or folate. Correlations between nutrient content, species, cultivation status, or geographic region were limited. Varietal selection or plant breeding offer tools to augment nutrient content in peppers. Integration of nutrient rich pepper types into diets that already include peppers could help combat nutrient deficiencies by providing a significant portion of recommended daily nutrients.

Metabolic Fate of Luteolin in Rats: Its Relationship to Anti-inflammatory Effect

Luteolin is a naturally occurring flavone that reportedly has anti-inflammatory effects. Because most luteolin is conjugated following intestinal absorption, free luteolin is likely present at low levels in the body. Therefore, luteolin metabolites are presumably responsible for luteolin bioactivity. Here we confirmed that luteolin glucuronides, especially luteolin-3'-O-glucuronide, are the major metabolites found in plasma after oral administration of luteolin (aglycone) or luteolin glucoside (luteolin-7-O-glucoside) to rats. Luteolin-4'-O-glucuronide and luteolin-7-O-glucuronide were also detectable together with luteolin-3'-O-glucuronide in the liver, kidney, and small intestine. Next, we prepared these luteolin glucuronides and compared the anti-inflammatory effects of luteolin and luteolin glucuronides on gene expression in lipopolysaccharide-treated RAW264.7 cells. Luteolin glucuronides, especially luteolin-7-O-glucuronide, reduced expression of inflammatory genes in the cells, although their effects were weaker than those of luteolin. These results indicate that the active compound responsible for the anti-inflammatory effect of luteolin in vivo would be luteolin glucuronide and/or residual luteolin.

Epithelial-to-Mesenchymal Transition in Paclitaxel-Resistant Ovarian Cancer Cells Is Downregulated by Luteolin

Ovarian cancer (OVCA) is the deadliest of all gynecological cancers which is attributed to late presentation, persistence, and development of chemoresistance. The objectives were to evaluate the association between OVCA paclitaxel-resistance and epithelial-to-mesenchymal transition (EMT) and to determine the capability of luteolin to chemosensitize OVCA cells. X10 and X22 cells were 11.8-25.3-fold and 7.8-8.6-fold resistant to paclitaxel than 1AP cells. X10 and X22 cells exhibited a mesenchymal phenotype, while 1AP has an epithelial characteristics. Furthermore, the expression of the epithelial marker E-cadherin was downregulated, while mesenchymal markers Vimentin and N-cadherin were upregulated in X10 and X22 cells when compared to 1AP cells. Transcription factors Snail, Slug, and Twist1 were upregulated in X10 cells, while Twist1 was highly expressed in X22 cells. Luteolin treatment caused cytotoxicity being most potent to X10 OVCA cells. Treatment of non-cytotoxic dose of luteolin at 15.625 μM chemosensitized X10 and X22 OVCA cells to paclitaxel as evidenced by reduced ED₅₀ values from 11.8 to 0.2 μM and 8.6 to 3.6 μM for X10 and X22 cells, respectively. Moreover, luteolin treatment led to a more epithelial phenotype of X10 and X22 cells and modification of EMT markers indicating reversal of EMT. The mechanism involved is through reduction of phosphorylation of FAK and ERK leading to reduced nuclear translocation of p65. Our results highlight the significance of EMT in OVCA resistance to paclitaxel and warrant the investigation of luteolin as a potential therapeutic agent in chemoresistant OVCA. J. Cell. Physiol. 232: 391-401, 2017. © 2016 Wiley Periodicals, Inc.

Quercetin and Its Anti-Allergic Immune Response

Quercetin is the great representative of polyphenols, flavonoids subgroup, flavonols. Its main natural sources in foods are vegetables such as onions, the most studied quercetin containing foods, and broccoli; fruits (apples, berry crops, and grapes); some herbs; tea; and wine. Quercetin is known for its antioxidant activity in radical scavenging and anti-allergic properties characterized by stimulation of immune system, antiviral activity, inhibition of histamine release, decrease in pro-inflammatory cytokines, leukotrienes creation, and suppresses interleukin IL-4 production. It can improve the Th1/Th2 balance, and restrain antigen-specific IgE antibody formation. It is also effective in the inhibition of enzymes such as lipoxygenase, eosinophil and peroxidase and the suppression of inflammatory mediators. All mentioned mechanisms of action contribute to the anti-inflammatory and immunomodulating properties of quercetin that can be effectively utilized in treatment of late-phase, and late-late-phase bronchial asthma responses, allergic rhinitis and restricted peanut-induced anaphylactic reactions. Plant extract of quercetin is the main ingredient of many potential anti-allergic drugs, supplements and enriched products, which is more competent in inhibiting of IL-8 than cromolyn (anti-allergic drug disodium cromoglycate) and suppresses IL-6 and cytosolic calcium level increase.

Ozone-induced changes in the content of bioactive compounds and enzyme activity during storage of pepper fruits

This paper presents for the first time the results of investigations concerning the effect of treatment of whole pepper fruits with gaseous ozone and the refrigeration storage period conditions on pepper quality. The effects are reflected in changes in the flavonoid contents, the antioxidant activity of the phenolic compound fraction and the enzymes involved in phenylpropanoid metabolism. The investigations were carried out on a hot pepper fruit cultivar, Cyklon. It was found that the levels of a majority of flavonoids, in particular those of quercetin 3-O-rhamnoside and quercetin 3-O-rhamnoside-7-O-glucoside increased in the pericarp of fruits treated with ozone for 3h and stored for 20days (by 25% relative to the control). Simultaneously, reduced phenylalanine ammonia-lyase and tyrosine ammonia-lyase activity were noted, which implies slight degradation of enzymes caused by the ozone treatment and enhancement of the polyphenol oxidase and guaiacol oxidase activity involved in response to increased oxidative stress.

Influence of Yellow Light-Emitting Diodes at 590 nm on Storage of Apple, Tomato and Bell Pepper Fruit

The objective of this study is to investigate the effects of irradiation from light-emitting diodes (LEDs) on several fruits during storage. To improve storage and increase the contents of some bioactive compounds, apple, tomato and red bell pepper fruits were exposed to yellow light emitted from the diodes at 590 nm. The contents of ascorbic acid, total phenolics, total flavonoids and several pigments were investigated, along with the antioxidant potential. The colour parameters (L*, a* and b*) and firmness of the fruit were also determined. After 7 days of LED light irradiation, there was significantly higher total phenolic content and antioxidant potential in apple peel extracts. The irradiated fruit of tomato had significantly higher levels of total phenolic compounds, and the fruit of red bell pepper had significantly higher antioxidant potential. LED light had no effects on the colour parameters, although there was a tendency to accelerate colour development. Apple fruit irradiated with LED light was significantly less firm. Among twelve analysed pigments, significantly more β-carotene was detected in LED light-irradiated apple and bell pepper fruit, more α-tocopherol and γ-tocopherol in bell pepper fruit, and more lutein in apple peel and bell pepper fruit. The applied LED light slightly accelerated the ripening of the studied fruit, and affected the synthesis of some of the secondary metabolites.

Antidiabetic properties of dietary flavonoids: a cellular mechanism review

Background

Natural food products have been used for combating human diseases for thousands of years. Naturally occurring flavonoids including flavones, flavonols, flavanones, flavonols, isoflavones and anthocyanidins have been proposed as effective supplements for management and prevention of diabetes and its long-term complications based on in vitro and animal models.

Aim

To summarize the roles of dietary flavonoids in diabetes management and their molecular mechanisms.

Findings

Tremendous studies have found that flavonoids originated from foods could improve glucose metabolism, lipid profile, regulating the hormones and enzymes in human body, further protecting human being from diseases like obesity, diabetes and their complications.

Conclusion

In the current review, we summarize recent progress in understanding the biological action, mechanism and therapeutic potential of the dietary flavonoids and its subsequent clinical outcomes in the field of drug discovery in management of diabetes mellitus.