Red raspberry and its anthocyanins: Bioactivity beyond antioxidant capacity

Malvidin induces hepatic stellate cell apoptosis via the endoplasmic reticulum stress pathway and mitochondrial pathway

Blueberries have great beneficial effects due to high level of anthocyanins, especially malvidin. Hepatic stellate cells (HSCs) can be activated and increase excessive extracellular matrix (ECM) components, which play a central role in liver fibrogenesis. Therefore, activated HSC's apoptosis can be induced to recover liver fibrosis. Malvidin's effects on apoptosis in rat activated hepatic stellate T6 cells (HSC-T6) in vitro were investigated here. High concentration of malvidin was found to significantly induce apoptosis, activate caspase-3, increase malondialdehyde, upregulate Bax, but downregulate Bcl-2. Moreover, malvidin upregulated the protein levels of some endoplasmic reticulum stress (ERS)-typical markers, including caspase-12, glucose-regulated protein 78 (GRP78), and CCAAT/enhancer-binding protein (C/EBP) homologous protein (CHOP), suggesting that malvidin induced HSC apoptosis by the ERS apoptosis pathway as well as the mitochondrial-dependent pathway. These findings indicated that blueberry anthocyanins, especially malvidin, could induce activated hepatic stellate cell apoptosis and might act as one kind of functional food ingredient or a novel nutraceutical beneficial for liver health.

The Anti-Depression-Like Effects of Zhengtian Capsule via Induction of Neurogenesis and the Neurotrophic Signaling Pathway

Oxidative stress that causes neural damages in neurodegenerative disorders has been widely studied for the pathogenesis and diagnostic measures. Zhengtian capsule (ZTC), a type of traditional Chinese medicine for headaches, has been found to have extra effects in recent years, such as promoting the release of serotonin and dopamine in the brain, but its specific mechanism has not been clearly elucidated. In this study, we focus on revealing whether ZTC can regulate key proteins of neurotrophic signaling pathway to alleviate depression-like behavior caused by oxidative stress. Experimental results show that ZTC (M 0.34 and H 0.7 g/kg) can elevate the proliferation of neural stem cells and GABAergic-type neurons in the hippocampus, promote the protein levels of BDNF, phosphorylated ERK1/2, and CREB, and inhibit the expression level of a key inflammation factor NFκB in a dose-dependent manner. These data suggest ZTC acts on multiple pathways to resist excessive oxidative stress, proving it to be a potential neurotrophic drug.

Food-derived bioactive compounds with anti-aging potential for nutricosmetic and cosmeceutical products

Besides providing essential nutrients for humans, food contains bioactive compounds that exert diverse biological activities such as anti-microbial, anti-cancerogenic, anti-viral, anti-inflammatory and antioxidant. The cosmetic industry is interested in natural bioactive compounds for their use in nutricosmetic and cosmeceutical products. These products aimed to reduce skin aging, inflammation or provide photoprotection against UV radiation. As a result, nutricosmetics and cosmeceuticals are becoming innovative self-care products in the beauty market. These products contain phytochemicals as active compounds obtained from fruits, vegetables, legumes, medicinal herbs and plants with anti-aging potential. This review summarizes the information within the last 5 years related to bioactive compounds present in fruits, vegetables, herbs and spices commonly used for human consumption. Their antioxidant and biological potential for modulating molecular markers involved in the aging process, as well as their mechanism of action. Diverse natural foods and their byproducts could be used as a source of bioactive compounds for developing cosmeceutical and nutricosmetic products.

Insights into the major aroma-active compounds in clear red raspberry juice (Rubus idaeus L. cv. Heritage) by molecular sensory science approaches

The major aroma-active compounds in clear red raspberry juice were identified by molecular sensory science approaches. Thirty-one aroma-active compounds were identified using detection frequency analysis and aroma extract dilution analysis. Among them, 18 volatiles with aroma activity in red raspberry were identified for the first time, while 14 volatiles with odor activity values (OAVs) ≥ 1 were confirmed as the major aroma-active compounds. Three C6 aldehydes showed the highest detection frequencies of 8, and β-ionone exhibited the highest OAV of 9507 and flavor dilution factor of 512, which indicated that the floral and grassy note could be dominant in overall aroma. Quantitative descriptive analysis suggested that the grassy, floral, woody, and caramel-like notes can be simulated using aroma recombination model 1. Electronic nose analysis also demonstrated that model 1 had closer similarity to the original juice than others. The combination strategy used here would help improve the knowledge of red raspberry aroma.

Recovery of Anthocyanins from Passion Fruit Epicarp for Food Colorants: Extraction Process Optimization and Evaluation of Bioactive Properties

The potential of passion fruit (Passiflora edulis Sims) epicarp to produce anthocyanin-based colorants with bioactive properties was evaluated. First, a five-level three-factor factorial design coupled with response surface methodology was implemented to optimize the extraction of anthocyanins from dark purple epicarps. The extraction yield and cyanidin-3-O-glucoside content were used as response criteria. The constructed models were fitted to the experimental data and used to calculate the optimal processing conditions (t = 38 min, T = 20 °C, S = 0% ethanol/water (v/v) acidified with citric acid to pH 3, and R_S/L = 50 g/L) that lead to maximum responses (3.4 mg/g dried epicarp and 9 mg/g extract). Then, the antioxidant, antimicrobial, and cytotoxic activities of anthocyanin extracts obtained using the optimized method and a conventional extraction method were evaluated in vitro. The extract obtained by the optimized method revealed a higher bioactivity, in agreement with the higher cyanidin-3-O-glucoside content. This study highlighted the coloring and bioactive potential of a bio-based ingredient recycled from a bio-waste, which promotes a sustainable bioeconomy in the agri-food sector.

Effect of microencapsulation using soy protein isolate and gum arabic as wall material on red raspberry anthocyanin stability, characterization, and simulated gastrointestinal conditions

This study involves microencapsulation of anthocyanin extract (AC) from red raspberry using a freeze drying technique involving ultrasonication of soy protein isolate (SPI), gum arabic (AG), and their combination. Analyses included microcapsule properties, encapsulation efficiency, antioxidant capacity using the DPPH assay, Fourier-transform infrared spectroscopy (FTIR), color, thermal stability, stability during storage, morphology, and simulated gastrointestinal conditions. Encapsulation efficiency (EE) ranged from 93.05% to 98.87% for all microcapsules. The morphology of microcapsules by scanning electron microscopy (SEM) indicated a broken glass shape, with mean size of microcapsules ranging from 21.07 ± 2.71 μm to 48.19 ± 2.33 μm using Mastersizer analyzer. A good relationship obtained between zeta potential (ZP) and FTIR spectrum indicated that there is a chemical cross linking interaction between wall material and core material. All microcapsules enhanced the thermal stability of AC in the temperature range 80-114 °C. Furthermore, AC retention (up to 48%) during storage at 37 °C for 60 days revealed that treatment H combination of SPI and AG was best. In addition, SPI and AG combination presented good release behavior under simulated gastrointestinal conditions compared with unencapsulated anthocyanin.

Preparation and pH Controlled Release of Fe3O4/Anthocyanin Magnetic Biocomposites

Anthocyanins are a class of antioxidants extracted from plants, with a variety of biochemical and pharmacological properties. However, the wide and effective applications of anthocyanins have been limited by their relatively low stability and bioavailability. In order to expand the application of anthocyanins, Fe3O4/anthocyanin magnetic biocomposite was fabricated for the storage and release of anthocyanin in this work. The magnetic biocomposite of Fe3O4 magnetic nanoparticle-loaded anthocyanin was prepared through physical intermolecular adsorption or covalent cross-linking. Scanning electron microscopy (SEM), Dynamic light scattering (DLS), Fourier-transform infrared spectroscopy (FTIR), X-ray diffractometry (XRD) and thermal analysis were used to characterize the biocomposite. In addition, the anthocyanin releasing experiments were performed. The optimized condition for the Fe3O4/anthocyanin magnetic biocomposite preparation was determined to be at 60 °C for 20 h in weak alkaline solution. The smooth surface of biocomposite from SEM suggested that anthocyanin was coated on the surface of the Fe3O4 particles successfully. The average size of the Fe3O4/anthocyanin magnetic biocomposite was about 222 nm. Under acidic conditions, the magnetic biocomposite solids could be repeatable released anthocyanin, with the same chemical structure as the anthocyanin before compounding. Therefore, anthocyanin can be effectively adsorbed and released by this magnetic biocomposite. Overall, this work shows that Fe3O4/anthocyanin magnetic biocomposite has great potential for future applications as a drug storage and delivery nanoplatform that is adaptable to medical, food and sensing.

The Effect of the Addition of Blue Honeysuckle Berry Juice to Apple Juice on the Selected Quality Characteristics, Anthocyanin Stability, and Antioxidant Properties

Apple juice is rich in phenolic compounds that are important as natural antioxidants. In turn, blue honeysuckle berry juice is a valuable source of bioactive ingredients and can be an interesting and beneficial supplement to fruit juices. The aim of this study was to examine the physicochemical and sensory properties of the newly designed mixture of apple juice and blue honeysuckle berry juice. The addition of blue honeysuckle berry juice to apple juice had a significant effect on the content of anthocyanin and vitamin C in the newly designed fruit juices. After production, the content of anthocyanins and polyphenols in the blue honeysuckle berry juice was high (595.39 and 767.88 mg/100 mL, respectively). As the concentration of blue honeysuckle berry juice added to apple juice was increased, the polyphenol content also increased. The juices analyzed after 4 months of storage were lighter and showed a less intense red color than the juices analyzed directly after production. Antioxidant activity (ABTS assay) in the apple juice mixed with 10% blueberry juice was almost 3 times higher than the pure apple juice after 3 months of storage; the addition of 30% blueberry juice significantly increased the antioxidant activity of the apple juice. Thus, the results of this research have expanded the existing knowledge about the health and sensory properties of apple juice mixed with blue honeysuckle berry juice. These findings can be utilized in further research aiming at the development of new products that can meet consumer expectations.

Ma Xing Shi Gan Decoction Attenuates PM2.5 Induced Lung Injury via Inhibiting HMGB1/TLR4/NFκB Signal Pathway in Rat

Ma Xing Shi Gan Decoction (MXD), a classical traditional Chinese medicine prescription, is widely used for the treatment of upper respiratory tract infection. However, the effect of MXD against particulate matters with diameter of less than 2.5 μm (PM2.5) induced lung injury remains to be elucidated. In this study, rats were stimulated with PM2.5 to induce lung injury. MXD was given orally once daily for five days. Lung tissues were harvested to assess pathological changes and edema. Myeloperoxidase (MPO) activity and malonaldehyde (MDA) content in lung were determined to evaluate the degree of injury. To assess the barrier disruption, the bronchoalveolar lavage fluid (BALF) was collected to determine the total protein content and count the number of neutrophils and macrophages. For evaluating the activation of macrophage in lung tissue, CD68 was detected using immunohistochemistry (IHC). The levels of inflammatory factors including tumor necrosis factor-alpha (TNF-α), interleukin-1beta (IL-1β), and interleukin-6 (IL-6) in BALF and serum were measured. In vitro, a PM2.5-activated RAW 264.7 macrophages inflammatory model was introduced. To evaluate the protective effect of MXD-medicated serum, the cell viability and the release of inflammatory factors were measured. The effects of MXD on the High mobility group box-1/Toll-like receptor 4/Nuclear factor-kappa B (HMGB1/TLR4/NFκB) pathway in lung tissue and RAW 264.7 cells were assessed by Western blot. For further confirming the protective effect of MXD was mediated by inhibiting the HMGB1/TLR4/NFκB pathway, RAW 264.7 cells were incubated with MXD-medicated serum alone or MXD-medicated serum plus recombinant HMGB1 (rHMGB1). MXD significantly ameliorated the lung injury in rats, as evidenced by decreases in the pathological score, lung edema, MPO activity, MDA content, CD68 positive macrophages number, disruption of alveolar capillary barrier and the levels of inflammatory factors. In vitro, MXD-medicated serum increased cell viability and inhibited the release of inflammatory cytokines. Furthermore, MXD treatment was found to inhibit HMGB1/TLR4/NFκB signal pathway both in vivo and in vitro. Moreover, the protection of MXD could be reversed by rHMGB1 in RAW 264.7. Taken together, these results suggest MXD protects rats from PM2.5 induced acute lung injury, possibly through the modulation of HMGB1/TLR4/NFκB pathway and inflammatory responses.

Ultrasonic and microwave activation of raspberry extract: antioxidant and anti-carcinogenic properties

Safe and healthy nutrition has a beneficial effect on human well-being. Various foods, such as berries, are known to inhibit cancer-promoting pre-proliferative signals. Among European fruit and berry crops, raspberries demonstrate one with the widest ranges of biologically active substances. Extraction remains a reliable method of obtaining biologically active substances from plant materials. The research objective was to obtain a semi-finished raspberry product by using microwave and ultrasonic processing and to study its antioxidant, anti-carcinogenic, sensory, physico-chemical, and microbiological properties. The raspberry extracts were obtained by maceration, ultrasound treatment, and microwave processing. After that, the samples underwent a comparative analysis of their antioxidant properties. The ultrasonic method gave the best results. A set of experiments made it possible to define the optimal technological modes for the extraction process: ethanol = 50%, ultrasonic radiation = 35 kHz, temperature = 40 ± 5°C, time = 120 min, water ratio = 1:10. A set of experiments on cell cultures demonstrated that the raspberry extract was able to reduce the expression of the anti-inflammatory COX-2, iNOS, and IL-8 genes. Hense, we recommend further studies of the effect of the raspberry extract on the induced expression of COX-2, iNOS, and IL-8. In addition, its anticarcinogenic properties have to be studied in vivo.

Isolation of strawberry anthocyanin-rich fractions and their mechanisms of action against murine breast cancer cell lines

The aim of this study was the evaluation of the effects of strawberry anthocyanin extract treatment on two in vitro models of murine breast cancer cell lines, in an attempt to detect a specific pathway (AMP-activated protein kinase or AMPK) through which strawberries exert their anticancer activity. The anticancer activity of purified anthocyanin extracts from an Alba cultivar on two murine cancer cell lines, N202/1A (with high levels of the HER2/neu oncogene) and N202/1E (with low levels of the HER2/neu oncogene), was evaluated after 48 and 72 h of treatment. The cell viability and apoptosis, intracellular ROS rates, and cell oxidative damage were assessed. Western blot assays were performed to analyze the expression of several proteins related to apoptosis, autophagy, metastasis, the oxidative status, mitochondrial functionality, and the AMPK pathway. This study demonstrated that the anthocyanin extract of Alba strawberry shows an antiproliferative effect on cancer cells, through the induction of apoptosis and oxidative stress, by stimulating different molecular pathways. This study is one of the first studies that have tried to deepen the understanding of a candidate pathway for the explanation of the effects of strawberry on cancer cells. A relationship between the AMPK pathway and the anticancer effects of strawberries was demonstrated.

Protective effects of raspberry on the oxidative damage in HepG2 cells through Keap1/Nrf2-dependent signaling pathway

The aim of the present study was to explore the protective effects of raspberry and its bioactive compound cyanidin 3-O-glucoside against H₂O₂-induced oxidative stress in HepG2 cells. We established a model of oxidative stress in HepG2 cells induced by H₂O₂ and examined the protein expression of Keap1/Nrf2. The antioxidant activity of raspberry extract was carried out measuring the level of reactive oxygen species (ROS), and the changes of phase II detoxification elements such as GSH level and CAT activity. Also the expression of proteins related to the Keap1/Nrf2 signaling was tested. The results revealed that raspberry extract significantly reduced the ROS levels in oxidative injured cells, increased GSH content and CAT activity, and activated the expression of proteins Keap1, Nrf2, HO-1, NQO1, and γ-GCS. These results taken together indicated that raspberry treatment could ameliorate H₂O₂-induced oxidative stress in HepG2 cells via Keap1/Nrf2 pathway.

COX-2/iNOS regulation during experimental hepatic injury and its mitigation by cloudy apple juice

A number of enzymes and transcription factors have been correlated with disease etiology. In this study, involvement of cyclooxygenase-2 and inducible-nitric oxide synthase is examined during diethylnitrosamine (DEN)-induced hepatic injury and cloudy apple juice (CAJ) supplementation. Liver injury was administered in rats by single dose of DEN (10 ml/kg bwt of 1% DEN), while 10 ml/kg bwt CAJ daily was given after 2 h of latency in DEN-treated animals for two weeks. CAJ was characterized by HPLC and subsequently examined for antioxidant power. During the course of treatment liver function, collagen (hydroxyproline), malondialdehyde, protein oxidation, antioxidant enzymes, ATPases, nitrite levels were investigated along with liver histopathology and electron microscopy. COX-2 and iNOS proteins were also localized in liver specimens. The results demonstrated rich polyphenols and antioxidant activity in CAJ. CAJ supplementation significantly restored liver biochemistry and anatomy as revealed by the refurbished investigated parameters. CAJ treatment also declined COX-2 and iNOS activities in injured animals. Electron microscopy demonstrated rejuvenated hepatocytes, Kupffer cells, RER, mitochondria and nucleus in CAJ supplemented animals. The novel outcomes of this study suggest that CAJ potentiates hepatoprotection by stimulating antioxidant power and regulating the COX-2 and iNOS proteins in the liver during experimental liver injury.

Elucidation of The Anti-Inflammatory Effect of Vanillin In Lps-Activated THP-1 Cells

Vanillin, a kind of phenolic compound, is naturally found in food and beverage and widely used as a flavoring agent. In view of the safety and universality of vanillin, exploring the functions of vanillin on human is of great value. Thus, lipopolysaccharide (LPS)-activated THP-1 cells were selected as the cell model to evaluate the anti-inflammatory effect of vanillin in this study. On the basis of the results, vanillin markedly suppressed the expression of inflammatory cytokines (that is, TNF-α, IL-1β, IL-6, and IL-8), mediators (NO, iNOS, PGE2, and COX-2), and NLRP3 inflammasome (that is, NLRP3, ASC, and caspase-1), blocked the LPS-induced activation of the NF-κB/IκBα/AP-1 signaling pathway, and activated the gene expression of the Nrf2/HO-1 signaling pathway. In addition, it was confirmed that vanillin was unable to react with LPS due to the results of quantification by HS-SPME-GC-MS. Hence, vanillin could effectively attenuate LPS-induced inflammatory response by regulating the expression of intracellular signaling pathways in THP-1 cells. It is a potent anti-inflammatory component found in food and beverage. These findings might contribute to the overall understanding of the potential health benefits of vanillin for food application. PRACTICAL APPLICATION: In this study, the anti-inflammatory effect of vanillin (VA) was evaluated by ELISA, real-time PCR, and western blot in LPS-induced THP-1 cells. The hypothesis that VA could react with LPS was excluded due to the results of quantification by HS-SPME-GC-MS. On the basis of the result, vanillin could effectively attenuate LPS-induced inflammatory response in THP-1 cells and was a potent anti-inflammatory component natural in food and beverage. These findings might contribute to the overall understanding of the potential health benefits of vanillin for food application.

Rubus ulmifolius Schott as a Novel Source of Food Colorant: Extraction Optimization of Coloring Pigments and Incorporation in a Bakery Product

(1) Background: Color has been considered to be the flashiest attribute of foodstuffs and researchers have shown a great interest in the extraction of pigmented compounds from vegetal products, with the purpose to provide alternative counterparts to the food industry; (2) Methods: This study aimed to explore Rubus ulmifolius Schott fruits as a potential source of anthocyanins, optimizing the extraction method, evaluating the bioactivity and incorporating the rich extract into a bakery food product; (3) Results: After the extraction optimization, results showed R. ulmifolius fruits to be a great source of anthocyanins, obtaining an amount of 33.58 mg AT/g E, with an extraction yield of 62.08%. The rich anthocyanin extract showed antitumor and antimicrobial potential in some tumor cell lines and strains, respectively, as well as the absence of toxicity; (4) Conclusions: The extract when incorporated in a bakery product showed a good coloring capacity, maintaining the nutritional value, revealing its use to be a great approach for replacing artificial colorants.

Immobilization of Andean berry (Vaccinium meridionale) polyphenols on nanocellulose isolated from banana residues: A natural food additive with antioxidant properties

Nanocellulose obtained from banana rachis (NCBR) was loaded (through simple impregnation) with a polyphenolic-rich extract (PRE) of Andean berries (Vaccinium meridionale). The adsorption/desorption of polyphenols onto NCBR and the thermal stability and antioxidant activity of the polyphenolic-NCBR nanocomplex (NCX) was studied. Thermodynamic properties (ΔH°_ads, ΔS°_ads and ΔG°_ads) showed that polyphenols interact with NCBR by physisorption through a spontaneous and exothermic process. The NCX kept the original color of PRE (magenta) and released polyphenols in aqueous medium (80% of phenolic compounds in the first hour and 50% of anthocyanins in the first few minutes). The NCX showed high antioxidant activity, as evidenced by traditional assays, and inhibited the peroxyl radicals mediated oxidation of a tryptophan-containing peptide. Additionally, NCX inhibited lipid peroxidation in an emulsified system of Sacha inchi oil exposed to accelerated oxidative conditions. In conclusion, the NCX showed good properties as an antioxidant with potential use as a food additive.

Processing raspberry-flavored whey drink using ohmic heating: Physical, thermal and microstructural considerations

The effect of ohmic heating processing (10, 100, 1000 Hz - 25 V;45, 60, 80 V - 60 Hz until 65 °C-30 min) on physical (color, rheology, particle size diameter), thermal (differential scanning calorimetry, DSC), physicochemical (time domain nuclear magnetic resonance, TD-NMR) and microstructural (optical microscopy) properties of raspberry-flavored whey drink was investigated. The samples were submitted to an ohmic system and conventional pasteurization (65 °C-30 min). Both processing led to increases in the color parameters (C*, h* and ∆E*) in the first 30 min. For the treatments, 10 Hz-25 V and 1000 Hz-25 V, more viscous, and consequently increased D[4,3] and D[3,2] values were observed, and similar results were obtained for the DSC behavior. The microstructure confirmed aggregation of cell structure in those configurations (10 Hz and 1000 Hz-25 V). OH, parameters for both ohmic configurations have an impact in all the evaluated parameters for raspberry-flavored whey drink, which can be interesting for the dairy industry.

Anti-inflammatory Mechanism Involved in 4-Ethylguaiacol-Mediated Inhibition of LPS-Induced Inflammation in THP-1 Cells

4-Ethylguaiacol, a common aroma compound of baijiu (a traditional Chinese alcoholic beverage), was assessed for its potential anti-inflammatory effects in an LPS-induced THP-1 cell model. To characterize the effect of 4-ethylguaiacol on the LPS-induced inflammatory response, the mRNA and protein expression of the TLR4-MAPKs-NF-κB-IκBα-AP-1, Nrf2-HO-1, and AMPK-SIRT1 pathways were monitored by ELISA, real-time PCR, and Western blotting. On the basis of the result, 4-ethylguaiacol exerted anti-inflammatory effects at doses of 10, 100, and 500 μM (the concentration of 4-ethylguaiacol in gujinggong baijiu is in the range of 1044 ± 44 to 1661 ± 63 μg/L) and significantly mitigated LPS-induced inflammation via activation of the Nrf2-HO-1 and AMPK-SIRT1 pathways and inhibition of NF-κB and AP-1 activation, thereby markedly inhibiting the activation of inflammasomes and down-regulating the production of inflammatory cytokines. These results indicated that 4-ethylguaiacol could reverse LPS-induced inflammatory responses and is a natural, potent anti-inflammatory component in baijiu.

Polyphenols and bioavailability: an update

Based on many cell culture, animal and human studies, it is well known that the most challenge issue for developing polyphenolics as chemoprevention or anti-diabtetic agents is the low oral bioavailability, which may be the major reason relating to its ambiguous therapeutic effects and large inter-individual variations in clinical trials. This review intends to highlight the unscientific evaluation on the basis of the published data regarding in vitro bioactivity of polyphenols, which may sometimes mislead the researchers and to conclude that: first, bio-accessibilities values obtained in the studies for polyphenols should be highly reconsidered in accordance with the abundant newly identified circulating and excreted metabolites, with a particular attention to colonic metabolic products which are obviously contributing much more than expected to their absorptions; second, it is phenolic metabolites, which are formed in the small intestine and hepatic cells,low molecular weight catabolic products of the colonic microflora to travel around the human body in the circulatory system or reach body tissues to elicit bioactive effects. It is concluded that better performed in vivo intervention and in vitro mechanistic studies are needed to fully understand how these molecules interact with human physiological and pathological processes.

Raspberry anthocyanin consumption prevents diet-induced obesity by alleviating oxidative stress and modulating hepatic lipid metabolism

Evidence indicates that raspberries have beneficial effects on chronic diseases. The objective of this study was to examine the beneficial effects of raspberry anthocyanin (RA) on high fat diet-induced obesity and investigate the underlying molecular mechanism. C57BL/6 mice were administered a low-fat diet, high-fat diet, and high-fat diet supplemented with RA at a dose of 200 mg kg-1 of food for 12 weeks. It was found that RA reduced the body weight gain by 63.7%. Furthermore, RA significantly elevated serum superoxide dismutase (SOD) and glutathione peroxidase (GSH-PX) activities and fecal butyric acid level, remarkably reduced the serum and hepatic lipid profiles, and markedly down-regulated the expression of the tumor necrosis factor α (TNFα), interleukin-6 (IL-6), and nuclear factor κB (NF-κB) genes. Metabolomics analysis conducted using gas chromatography time-of-flight mass spectrometry (GC-TOF/MS) indicated that RA administration promoted the recovery of metabolites involved in glycerophospholipid metabolism, insulin signaling pathway, and glutathione metabolism in the livers of obese mice. These findings suggest that RA may ameliorate diet-induced obesity by alleviating oxidative stress and modulating lipid metabolism.

Comparison of Antioxidant Activities of Different Grape Varieties

Grapes are widely consumed in the world, and different grape varieties could exhibit distinctly different antioxidant activities. In this study, the free radical-scavenging and antioxidant activities of lipophilic, hydrophilic, and insoluble-bound fractions from 30 grape varieties were evaluated by ferric-reducing antioxidant powers (FRAP), Trolox equivalent antioxidant capacities (TEAC), total phenolic contents (TPC), and total flavonoid contents (TFC). The results indicated that the 30 grape varieties exhibited diverse FRAP values (1.289⁻11.767 μmol Fe(II)/g FW), TEAC values (0.339⁻4.839 μmol Trolox/g FW), TPC values (0.294⁻1.407 mg GAE/g FW) and TFC values (0.082⁻0.132 mg QE/g FW). Several grapes, such as Pearl Black Grape (Xinjiang), Summer Black Grape (Shaanxi), Pearl Green Grape (Xinjiang), Seedless Green Grape (Xinjiang), and Seedless Red Grape (Yunnan), exhibited strong free radical-scavenging and antioxidant activities, which could be consumed as good sources of natural antioxidants to prevent several diseases induced by oxidative stress, such as cardiovascular disease and cancer. Furthermore, several antioxidants were identified and quantified, including caffeic acid, catechin gallate, epicatechin, gallic acid, protocatechuic acid and rutin, which could contribute to the antioxidant activities of grapes.

Effect of the frying process on the composition of hydroxycinnamic acid derivatives and antioxidant activity in flesh colored potatoes

Phenolic composition of potatoes (Solanum tuberosum) with colored flesh has been previously reported, highlighting their anthocyanin composition. However, there is less information available about the profiles and concentrations of hydroxycinnamic acid derivatives (HCADs) in these potatoes. In pigmented potatoes from Southern Chile, three HCADs have been detected, corresponding to the trans isomers of 3-, 4- and 5-caffeoylquinic acid. It is remarkable that after frying, the HCAD concentrations increased 493% compared to those of fresh potatoes. The same tendency has been observed for total phenols and antioxidant activity of the chips. The results obtained are relevant in relation to the classification of pigmented potatoes as functional foods not only due to their anthocyanin content but also due to their higher content of HCADs, especially since their concentration increases considerably after frying, thus contributing to their antioxidant activity and potential beneficial effects for human health compared with uncolored genotypes.

Structure-affinity relationship of dietary anthocyanin–HSA interaction

BACKGROUND: Dietary anthocyanins are plant pigments which occur with different chemical structures, being widely present in fruits and in many vegetables, are claimed to be beneficial for human health. The bioavailability of anthocyanins is the key factor influencing their health benefits. OBJECTIVE: Herein, the molecular structure-affinity relationship of anthocyanin–human serum albumin interaction was investigated. METHODS: Fluorescence quenching method was applied to determine the binding affinities of anthocyanins for human serum albumin. RESULTS: Demethylation of the methoxyl groups in anthocyanins enhanced the binding affinities. The number and position of the hydroxyl groups on ring [B] affect the affinities of anthocyanins for human serum albumin. The glycosylation of hydroxyl groups on ring [C] enhanced their binding affinities for human serum albumin. CONCLUSIONS: Anthocyanidins and anthocyanins, show different characteristics for their binding to human serum albumin when the methoxyl groups on the ring B are demethylated or hydroxylated.

Protective Effects of Blueberry Anthocyanins against H2O2-Induced Oxidative Injuries in Human Retinal Pigment Epithelial Cells

Blueberry anthocyanins are considered protective of eye health because of their recognized antioxidant properties. In this study, blueberry anthocyanin extract (BAE), malvidin (Mv), malvidin-3-glucoside (Mv-3-glc), and malvidin-3-galactoside (Mv-3-gal) all reduced H₂O₂-induced oxidative stress by decreasing the levels of reactive oxygen species and malondialdehyde and increasing the levels of superoxide dismutase, catalase, and glutathione peroxidase in human retinal pigment epithelial cells. BAE and the anthocyanin standards enhanced cell viability from 63.69 ± 3.36 to 86.57 ± 6.92% (BAE), 115.72 ± 23.41% (Mv), 98.15 ± 9.39% (Mv-3-glc), and 127.97 ± 20.09% (Mv-3-gal) and significantly inhibited cell apoptosis (P < 0.01 for all). Mitogen-activated-protein-kinase pathways, including ERK1/2 and p38, were involved in the bioactivities. In addition, the anthocyanins decreased vascular-endothelial-cell-growth-factor levels and activated Akt-signal pathways. These combined results supported the hypothesis that blueberry anthocyanins could inhibit the induction and progression of age-related macular degeneration (AMD) through antioxidant mechanisms.

Quantification and cytoprotection by vanillin, 4-methylguaiacol and 4-ethylguaiacol against AAPH-induced abnormal oxidative stress in HepG2 cells

Vanillin, 4-methylguaiacol, and 4-ethylguaiacol, three phenolic compounds in Gujinggong (GJG) Chinese baijiu (Chinese liquor), were quantified by liquid–liquid extraction (LLE) combined with gas chromatography-mass spectrometry (GC-MS) and evaluated for their possible cytoprotective effects by AAPH-induced HepG2 cell model. To confirm whether vanillin, 4-methylguaiacol, and 4-ethylguaiacol protected HepG2 cells against AAPH-induced abnormal oxidative stress via motivating the Keap1–Nrf2 pathway, the gene and protein expression of Nrf2, Keap1, SOD, CAT, and GPx from the Keap1–Nrf2 pathway were measured with real-time PCR and western blot. Three levels of treatment doses (1000, 500, and 100 mg L⁻¹) were applied. Results showed that vanillin, 4-methylguaiacol, and 4-ethylguaiacol exhibited potent cytoprotective effect in a dose-dependent manner, greatly alleviating or reversing the increased oxidative stress induced by AAPH through up-regulating the mRNA and protein expression levels of Nrf2, SOD, CAT, and GPx, and thereby, significantly improving the intracellular antioxidant defense system in HepG2 cells (p < 0.05). Based on these findings, it was confirmed that vanillin, 4-methylguaiacol, and 4-ethylguaiacol, natural components of Chinese baijiu, were able to modulate the expression of Nrf2 and its downstream antioxidative enzymes (i.e., SOD, CAT, and GPx) against AAPH-induced abnormal oxidative stress. Further, this study lays the foundation for better illustrating the health benefits of Chinese baijiu.

Vanillin, 4-methylguaiacol, and 4-ethylguaiacol widely exist in Gujinggong Chinese baijiu and could protect HepG2 cells against oxidative stress via activating the Nrf2 pathway.

Hepatoprotective effects of raspberry (Rubus coreanus Miq.) seed oil and its major constituents

Raspberry seed is a massive byproduct of raspberry juice and wine but usually discarded. The present study employed a microwave-assisted method for extraction of raspberry seed oil (RSO). The results revealed that omega-6 fatty acids (linoleic acid and γ-linolenic acid) were the major constituents in RSO. Cellular antioxidant enzyme activity such as superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase (CAT) were investigated in HepG2 cells treated with RSO. Induction of the synthesis of several antioxidants in H₂O₂-exposed HepG2 cells was found. RSO increased the enzyme activity of SOD, CAT, and GPx in H₂O₂-exposed HepG2. Furthermore, RSO inhibited the phosphorylation of upstream mitogen-activated protein kinases (MAPK) such as c-Jun N-terminal kinase (c-JNK) and extracellular signal-regulated kinase (ERK). Taken together, the possible mechanisms to increase antioxidant enzyme activities in HepG2 may through the suppression of ERK and JNK phosphorylation. Raspberry seed oil exhibited good effects on the activities of the intracellular antioxidant enzymes and seems to protect the liver from oxidative stress through the inhibition of MAPKs.

Intracellular antioxidant effect of vanillin, 4-methylguaiacol and 4-ethylguaiacol: three components in Chinese Baijiu

Vanillin, 4-methylguaiacol, and 4-ethylguaiacol can improve AAPH-induced alterations in oxidative stress biomarkers and antioxidant enzymes in HepG2 cells.