Strawberry (Fragaria × ananassa cv. Romina) methanolic extract promotes browning in 3T3-L1 cells.

In recent years, the conversion of white adipocytes to brown-like adipocytes by pharmacological and dietary compounds has gained attention as an effective strategy to fight obesity. Strawberry bioactive compounds present several biological activities including antioxidant, anti-inflammatory, anti-cancer, anti-atherosclerotic and antiadipogenic properties. However, to the best of our knowledge, the possible role of strawberry bioactive compounds in white adipose tissue (WAT) browning has never been explored. Our results demonstrated that a strawberry methanolic extract (SE) significantly reduced 3T3-L1 pre-adipocytes differentiation, and down-regulated the mRNA expression of the adipogenic transcription factors CCAAT/enhancer-binding protein (C/REB- α) and peroxisome proliferation-activated receptor (PPAR-γ). It also down-regulated the mRNA expression of resistin and angiotensinogen, two genes considered as markers of white adipocytes, while increased the mRNA expression of pyruvate dehydrogenase lipoamide kinase isozyme 4 (PDK4) and uncoupling protein 1 (UCP1) which, conversely, are brown adipocyte-specific markers. Likewise, SE stimulated AMP-activated protein kinase (AMPKα), sirtuin 1 (Sirt1) and the peroxisome proliferator activated receptor gamma coactivator 1-alpha (PGC-1α), suggesting a possible increase in mitochondrial biogenesis. It also stimulated oxygen consumption rate and uncoupled respiration. Taken together, all these results suggest that SE induces brown fat-like phenotype in 3T3-L1 cells and may have potential therapeutic implications for treatment and/or prevention of obesity.

Strawberry extracts efficiently counteract inflammatory stress induced by the endotoxin lipopolysaccharide in Human Dermal Fibroblast.

A protracted pro-inflammatory state is the common denominator in the development, progression and complication of the common chronic diseases. Dietary antioxidants represent an efficient tool to counteract this inflammatory state. The aim of the present work was to evaluate the effects of strawberry extracts on inflammation evoked by E. Coli lipopolysaccharide in Human Dermal Fibroblast, by measuring reactive oxygen species production, apoptosis rate, antioxidant enzymes activity, mitochondria functionality and also investigating the molecular pathway involved in inflammatory and antioxidant response. The results demonstrated that strawberry pre-treatment reduced intracellular reactive oxygen species levels, apoptotic rate, improved antioxidant defences and mitochondria functionality in lipopolysaccharide -treated cells. Strawberry exerted these protective activities through the inhibition of the NF-kB signalling pathway and the stimulation of the Nrf2 pathway, with a mechanism AMPK-dependent. These results confirm the health benefits of strawberry in the prevention of inflammation and oxidative stress condition in lipopolysaccharide-treated cells.

Strawberry-Based Cosmetic Formulations Protect Human Dermal Fibroblasts against UVA-Induced Damage.

Extreme exposure of skin to Ultraviolet A (UVA)-radiation may induce a dysregulated production of reactive oxygen species (ROS) which can interact with cellular biomolecules leading to oxidative stress, inflammation, DNA damage, and alteration of cellular molecular pathways, responsible for skin photoaging, hyperplasia, erythema, and cancer. For these reasons, the use of dietary natural bioactive compounds with remarkable antioxidant activity could be a strategic tool to counteract these UVA-radiation-caused deleterious effects. Thus, the purpose of the present work was to test the efficacy of strawberry (50 µg/mL)-based formulations supplemented with Coenzyme Q10 (100 µg/mL) and sun protection factor 10 in human dermal fibroblasts irradiated with UVA-radiation. The apoptosis rate, the amount of intracellular reactive oxygen species (ROS) production, the expression of proteins involved in antioxidant and inflammatory response, and mitochondrial functionality were evaluated. The results showed that the synergic topical use of strawberry and Coenzyme Q10 provided a significant (p < 0.05) photoprotective effect, reducing cell death and ROS, increasing antioxidant defense, lowering inflammatory markers, and improving mitochondrial functionality. The obtained results suggest the use of strawberry-based formulations as an innovative, natural, and useful tool for the prevention of UVA exposure-induced skin diseases in order to decrease or substitute the amount of synthetic sunscreen agents.

Strawberry (cv. Romina) Methanolic Extract and Anthocyanin-Enriched Fraction Improve Lipid Profile and Antioxidant Status in HepG2 Cells.

Dyslipidemia and oxidation of low density lipoproteins (LDL) are recognized as critical factors in the development of atherosclerosis. Healthy dietary patterns, with abundant fruit and vegetable consumption, may prevent the onset of these risk factors due to the presence of phytochemical compounds. Strawberries are known for their high content of polyphenols; among them, flavonoids are the major constituents, and it is presumed that they are responsible for the biological activity of the fruit. Nevertheless, there are only a few studies that actually evaluate the effects of different fractions isolated from strawberries. In order to assess the effects of two different strawberry extracts (whole methanolic extract/anthocyanin-enriched fraction) on the lipid profile and antioxidant status in human hepatocellular carcinoma (HepG2) cells, the triglycerides and LDL-cholesterol content, lipid peroxidation, intracellular reactive oxygen species (ROS) content and antioxidant enzymes' activity on cell lysates were determined. Results demonstrated that both strawberry extracts not only improved the lipid metabolism by decreasing triglycerides and LDL-cholesterol contents, but also improved the redox state of HepG2 cells by modulating thiobarbituric acid-reactive substances production, antioxidant enzyme activity and ROS generation. The observed effects were more pronounced for the anthocyanin-enriched fraction.

Protective Effect of Strawberry Extract against Inflammatory Stress Induced in Human Dermal Fibroblasts.

A protracted pro-inflammatory state is a major contributing factor in the development, progression and complication of the most common chronic pathologies. Fruit and vegetables represent the main sources of dietary antioxidants and their consumption can be considered an efficient tool to counteract inflammatory states. In this context an evaluation of the protective effects of strawberry extracts on inflammatory stress induced by E. coli LPS on human dermal fibroblast cells was performed in terms of viability assays, ROS and nitrite production and biomarkers of oxidative damage of the main biological macromolecules. The results demonstrated that strawberry extracts exerted an anti-inflammatory effect on LPS-treated cells, through an increase in cell viability, and the reduction of ROS and nitrite levels, and lipid, protein and DNA damage. This work showed for the first time the potential health benefits of strawberry extract against inflammatory and oxidative stress in LPS-treated human dermal fibroblast cells.

A Pilot Study of the Photoprotective Effects of Strawberry-Based Cosmetic Formulations on Human Dermal Fibroblasts.

Strawberry polyphenols have been extensively studied over the last two decades for their beneficial properties. Recently, their possible use in ameliorating skin conditions has also been proposed; however, their role in preventing UVA-induced damage in cosmetic formulation has not yet been investigated. Skin is constantly exposed to several environmental stressors, such as UVA radiation, that induce oxidative stress, inflammation and cell death via the production of reactive oxygen species (ROS). In the present study, we assessed the potential photoprotective capacity of different strawberry-based formulations, enriched with nanoparticles of Coenzyme Q10 and with sun protection factor 10 (SPF10), in human dermal fibroblasts (HuDe) exposed to UVA radiation. We confirmed that strawberries are a very rich source of polyphenols, anthocyanins and vitamins, and possess high total antioxidant capacity. We also showed that strawberry extracts (25 µg/mL-1 mg/mL) exert a noticeable photoprotection in HuDe, increasing cell viability in a dose-dependent way, and that these effects are potentiated by the presence of CoQ10red (100 µg/mL). We have demonstrated for the first time that the topical use of strawberry extract may provide good photoprotection, even if more in-depth studies are strongly encouraged in order to evaluate the cellular and molecular effects of strawberry protection.

Polyphenol-rich strawberry extract protects human dermal fibroblasts against hydrogen peroxide oxidative damage and improves mitochondrial functionality.

Strawberry bioactive compounds are widely known to be powerful antioxidants. In this study, the antioxidant and anti-aging activities of a polyphenol-rich strawberry extract were evaluated using human dermal fibroblasts exposed to H2O2. Firstly, the phenol and flavonoid contents of strawberry extract were studied, as well as the antioxidant capacity. HPLC-DAD analysis was performed to determine the vitamin C and ß-carotene concentration, while HPLC-DAD/ESI-MS analysis was used for anthocyanin identification. Strawberry extract presented a high antioxidant capacity, and a relevant concentration of vitamins and phenolics. Pelargonidin- and cyanidin-glycosides were the most representative anthocyanin components of the fruits. Fibroblasts incubated with strawberry extract and stressed with H2O2 showed an increase in cell viability, a smaller intracellular amount of ROS, and a reduction of membrane lipid peroxidation and DNA damage. Strawberry extract was also able to improve mitochondrial functionality, increasing the basal respiration of mitochondria and to promote a regenerative capacity of cells after exposure to pro-oxidant stimuli. These findings confirm that strawberries possess antioxidant properties and provide new insights into the beneficial role of strawberry bioactive compounds on protecting skin from oxidative stress and aging.

An anthocyanin-rich strawberry extract protects against oxidative stress damage and improves mitochondrial functionality in human dermal fibroblasts exposed to an oxidizing agent.

This study investigates the protective effect of the Sveva strawberry polyphenol-rich extract on human dermal fibroblasts against AAPH-induced oxidative stress. The HPLC-DAD/ESI-MS analysis was used for evaluating the phenolic composition of the fruits. Sveva strawberry presented a high anthocyanin content (639.79 mg per kg fresh fruit), representing ∼86.08% of the total phenolic content, with Pg-3-glc as the most abundant representative (611.18 mg per kg fresh fruit). Only one ellagitannin (agrimoniin) was identified, while two quercetins, three kaempherol derivates, and three ellagic acid derivatives were detected and quantified. Strawberry pre-treatment (0.5 mg ml(-1)) markedly increased human dermal fibroblast viability, with a significant reduction of apoptotic and dead cells, and suppressed AAPH-induced ROS generation, after only 30 minutes of incubation with the oxidizing agent, and lipid peroxidation, against a range of AAPH concentrations tested. Notably, the strawberry extract also improved the mitochondrial functionality: the basal respiratory performance after treatment was ∼1.59-fold higher compared to control cells, while pre-treatment with strawberry extract before oxidative damage increased ∼2.70-fold compared to stressed cells. Our results confirm that the strawberry possesses antioxidant properties, and may be useful for the prevention of free radical-induced skin damage.

One-month strawberry-rich anthocyanin supplementation ameliorates cardiovascular risk, oxidative stress markers and platelet activation in humans.

Strawberries are an important fruit in the Mediterranean diet because of their high content of essential nutrients and beneficial phytochemicals, which seem to exert beneficial effects in human health. Healthy volunteers were supplemented daily with 500 g of strawberries for 1 month. Plasma lipid profile, circulating and cellular markers of antioxidant status, oxidative stress and platelet function were evaluated at baseline, after 30 days of strawberry consumption and 15 days after the end of the study. A high concentration of vitamin C and anthocyanins was found in the fruits. Strawberry consumption beneficially influenced the lipid profile by significantly reducing total cholesterol, low-density lipoprotein cholesterol and triglycerides levels (-8.78%, -13.72% and -20.80%, respectively; P<.05) compared with baseline period, while high-density lipoprotein cholesterol remained unchanged. Strawberry supplementation also significant decreased serum malondialdehyde, urinary 8-OHdG and isoprostanes levels (-31.40%, -29.67%, -27.90%, respectively; P<.05). All the parameters returned to baseline values after the washout period. A significant increase in plasma total antioxidant capacity measured by both ferric reducing ability of plasma and oxygen radical absorbance capacity assays and vitamin C levels (+24.97%, +41.18%, +41.36%, respectively; P<.05) was observed after strawberry consumption. Moreover, the spontaneous and oxidative hemolysis were significant reduced (-31.7% and -39.03%, respectively; P<.05), compared to the baseline point, which remained stable after the washout period. Finally, strawberry intake significant decrease (P<.05) the number of activated platelets, compared to both baseline and washout values. Strawberries consumption improves plasma lipids profile, biomarkers of antioxidant status, antihemolytic defenses and platelet function in healthy subjects, encouraging further evaluation on a population with higher cardiovascular disease risk.

Photoprotective potential of strawberry (Fragaria × ananassa) extract against UV-A irradiation damage on human fibroblasts.

Exposure to UV-A radiation is known to induce discrete lesions in DNA and the generation of free radicals that lead to a wide array of skin diseases. Strawberry (Fragaria × ananassa) contains several polyphenols with strong antioxidant and anti-inflammatory activities. Because the major representative components of strawberry are anthocyanins, these may significantly contribute to its properties. To test this hypothesis, methanolic extracts from the Sveva cultivar were analyzed for anthocyanin content and for their ability to protect human dermal fibroblasts against UV-A radiation, as assayed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenytetrazolium bromide and Comet assays. Five anthocyanin pigments were identified using high-performance liquid chromatography-diode array detection-electrospray ionization/mass spectrometry. Moreover, the strawberry extract showed a photoprotective activity in fibroblasts exposed to UV-A radiation, increasing cellular viability, and diminishing DNA damage, as compared to control cells. Overall, our data show that strawberry contains compounds that confer photoprotective activity in human cell lines and may protect skin against the adverse effects of UV-A radiation.

Strawberry consumption improves plasma antioxidant status and erythrocyte resistance to oxidative haemolysis in humans.

Significant increases in the plasma total antioxidant capacity (TAC) have already been reported after acute intake of strawberries. In addition, antihaemolitic effects of strawberry extracts have been recently demonstrated in vitro, revealing that part of the antioxidant properties of strawberry bioactive compounds could lie in their localisation within cell membranes. However, there is a lack of research evidence from in vivo protracted strawberry consumption studies. We carried out a 16-day pilot study where 12 healthy subjects ingested 500g of antioxidants-rich strawberries daily, and we evaluated the potential effects of fruit consumption on biomarkers of plasma and cellular antioxidant status. A significant increase in fasting plasma TAC and in serum vitamin C concentrations were progressively observed during the period of strawberry supplementation. An enhanced resistance to haemolysis was also observed in both AAPH-treated and untreated erythrocytes, collected during and after the period of strawberry consumption. The results obtained in this work suggest that regular consumption of antioxidant-rich strawberries may exert an improvement on the plasma antioxidant status and an increase on the antihaemolitic defenses of human erythrocytes.

Antioxidant and antimicrobial capacity of several monofloral Cuban honeys and their correlation with color, polyphenol content and other chemical compounds.

Several monofloral Cuban honeys were analyzed to determine their total phenolic, flavonoid, ascorbic acid, amino acid, protein and carotenoid contents as well as their radical-scavenging activity and antimicrobial capacities. The total phenolic, flavonoid and carotenoid contents varied considerably, and the highest values were obtained for Linen vine (Govania polygama (Jack) Urb) honey, which is classified as an amber honey. The highest amino acid content was found in Morning glory (Ipomoea triloba L.) while Liven vine had the highest protein content. Similarly Linen vine honey had the highest antioxidant activity while the lowest was found in Christmas vine (Turbina corymbosa (L.) Raf). Ascorbic acid was absent. Hydroxyl radical formation was studied by EPR and spin trapping, and it was found in all honeys tested. The antimicrobial activity was screened using two Gram-positive and Gram-negative bacteria. S. aureus was the most sensitive microorganism while Pseudomonas aeruginosa presented higher minimum active dilution values. Bacillus subtilis and Escherichia coli were both moderately sensitive to honey antimicrobial activity. A correlation between radical-scavenging activity and total phenolic content was found. Correlation existed also between color vs phenolics content, vs flavonoid content or between phenolic vs flavonoid.

Coenzyme Q concentration and total antioxidant capacity of human milk at different stages of lactation in mothers of preterm and full-term infants.

Coenzyme Q10(CoQ10) in human milk at different stages of maturity in mothers of preterm and full-term infants and its relation to the total antioxidant capacity of milk is described for the first time. Thirty healthy breastfeeding women provided colostrum, transition-milk and mature-milk samples. Coenzyme Q, alpha-, gamma- and delta-tocopherol, fatty acids and the total antioxidant capacity of the milk were analyzed. Coenzyme Q10 was found at higher concentrations for colostrum (0.81+/-0.06 vs. 0.50+/-0.05 micromol/l) and transition milk (0.75+/-0.06 vs. 0.45+/-0.05 micromol/l) in the full-term vs. the preterm group (similar results were found for total antioxidant capacity). Concentrations of alpha- and gamma-tocopherol were higher in the full-term group and decreased with time. In conclusion, CoQ10 is present in breast milk, with higher concentration in mothers of full-term infants. CoQ10 in breast milk decreases through lactation in mothers delivering full-term infants. Also, CoQ10, alpha- and gamma-tocopherol concentration in human milk directly correlates with the antioxidant capacity of the milk.

Assay of coenzyme Q(10) in plasma by a single dilution step.

A new method is described for determining coenzyme Q(10) (CoQ(10)) in plasma. The method is based on oxidation of CoQ(10) in the sample by treating it with para-benzoquinone followed by extraction with 1-propanol and direct injection into the HPLC apparatus. This method achieves a linear detector response for peak area measurements over the concentration range of 0.05-3.47 microM. Diode array analysis of the peak was consistent with CoQ(10) spectrum. Supplementation of the samples with known amounts of CoQ(10) yielded a quantitative recovery of 96-98.5%; the method showed a level of quantitation of 1.23 nmol per HPLC injection (200 microl of propanol extract containing 33.3 microl of plasma). A correlation of r = 0.99 (P < 0.0001) was found with a reference electrochemical detection method. Within run precision showed a CV% of 1.6 for samples approaching normal values (1.02 microM). Day-to-day precision was also close to 2%.