Pollen variability in Quercus L. species and relative systematic implications

This study aims to address one of the challenges related to the complexity of the Quercus L. genus, that is the identification of structural elements favouring the systematic identification of the oak pollen. Thus, in this contribution, we explored the variation of morphometric and chemical parameters in pollen samples collected from 47 different Quercus species and hybrids. Several qualitative (e.g., outline in polar view, class, aperture structures) and quantitative (e.g., diameter, exine and sporoderm thickness, autofluorescence, content in proteins and plant metabolites) features were evaluated by optic microscopy and spectrophotometric assays. Statistical analyses were also carried out to assess significant correlations and clustering effects among the studied taxa, based on phenotypical and biochemical data, to identify the parameters which could be useful for taxonomic discrimination at inter- and intra-specific level. Only few morphological traits showed the potentiality to be diagnostic, such as pollen diameter and outline in polar view. The intensity of pollen autofluorescence varied among the samples but it did not seem to correlate with protein, carotenoid, phenolic and flavonoid content. However, differences in protein and carotenoid levels were detected, suggesting them as possible taxonomic discriminants for oak pollen. Thus, our work represents a step forward in understanding morphology and biochemistry of oak pollen, constitutes an experimental set-up applicable in future systematic studies on other genera, and opens new perspectives for further molecular investigations on Quercus species.

Antioxidant Phytocomplexes Extracted from Pomegranate (Punica granatum L.) Using Hydrodynamic Cavitation Show Potential Anticancer Activity In Vitro

Hydrodynamic cavitation (HC), as an effective, efficient, and scalable extraction technique for natural products, could enable the affordable production of valuable antioxidant extracts from plant resources. For the first time, whole pomegranate (Punica granatum L.) fruits, rich in bioactive phytochemicals endowed with anti-cancer properties, were extracted in water using HC. Aqueous fractions sequentially collected during the process (M1-M5) were lyophilized (L), filtered (A), or used as such, i.e., crude (C), and analyzed for their biochemical profile and in vitro antioxidant power. The fractions M3 and M4 from the L and C series showed the highest antiradical activity and phytochemical content. While the lyophilized form is preferable for application purposes, sample L-M3, which was produced faster and with lower energy consumption than M4, was used to assess the potential antiproliferative effect on human breast cancer line (AU565-PAR) and peripheral blood mononuclear (PBMC) cells from healthy donors. In a pilot study, cell growth, death, and redox state were assessed, showing that L-M3 significantly reduced tumor cell proliferation and intracellular oxygen reactive species. No effect on PBMCs was detected. Thus, the antioxidant phytocomplex extracted from pomegranate quickly (15 min), at room temperature (30 °C), and efficiently showed potential anticancer activity without harming healthy cells.

Assessment of Phenolic Acid Content and Antioxidant Properties of the Pulp of Five Pumpkin Species Cultivated in Southeastern Poland

Antioxidant properties and phenolic acid content in the pulp of five pumpkin species were evaluated. The following species cultivated in Poland were included: Cucurbita maxima 'Bambino', Cucurbita pepo 'Kamo Kamo', Cucurbita moschata 'Butternut', Cucurbita ficifolia 'Chilacayote Squash', and Cucurbita argyrosperma 'Chinese Alphabet'. The content of polyphenolic compounds was determined by ultra-high performance liquid chromatography coupled with HPLC, while the total content of phenols and flavonoids and antioxidant properties were determined by spectrophotometric methods. Ten phenolic compounds (protocatechuic acid, p-hydroxybenzoic acid, catechin, chlorogenic acid, caffeic acid, p-coumaric acid, syringic acid, ferulic acid, salicylic acid, kaempferol) were identified. Phenolic acids were the most abundant compounds; the amount of syringic acid was found to be the highest, ranging from 0.44 (C. ficifolia) to 6.61 mg∙100 g^-1 FW (C. moschata). Moreover, two flavonoids were detected: catechin and kaempferol. They were found at their highest level of content in C. moschata pulp (catechins: 0.31 mg∙100 g^-1 FW; kaempferol: 0.06 mg∙100 g^-1 FW), with the lowest amount detected in C. ficifolia (catechins: 0.15 mg∙100 g^-1 FW; kaempferol below the limit of detection). Analysis of antioxidant potential showed significant differences depending on the species and the test used. The DPPH radical scavenging activity of C. maxima was 1.03 times higher than C. ficiofilia pulp and 11.60 times higher than C. pepo. In the case of the FRAP assay, the multiplicity of FRAP radical activity in C. maxima pulp was 4.65 times higher than C. Pepo pulp and only 1.08 times higher compared to C. ficifolia pulp. The study findings show the high health-promoting value of pumpkin pulp; however, the content of phenolic acids and antioxidant properties are species dependent.

Influence of environmental conditions on the production of nutraceuticals in Italian edible plant landraces

Autochthonous plant varieties, also referred to as landraces, represent an important genetic resource, being well-adapted to the environment in which they have been selected. Landraces usually show profiles rich in nutraceuticals, making them an effective and valuable alternative to commercial agri-products, as well as potential candidates for crop improvement programs. Basilicata region is recognized as an Italian hotspot for agrobiodiversity, due to its complex orography. Thus, this work aimed to characterize and monitor, for two successive years, the content of secondary metabolites and related antioxidant properties of seven different species, four officinal (i.e., wild fennel - Feoniculum vulgare Mill.; oregano - Origanum vulgare L.; thyme - Thymus vulgaris L.; valerian - Valeriana officinalis L.) and three fruit species (i.e., fig - Ficus carica L. cv. Dottato; sweet cherry Prunus avium L. cv. Majatica; plum - Prunus domestica L. cv. Cascavella Gialla), collected in three different sites of this region. In detail, spectrophotometric tests were performed to assess the concentration of phenolic compounds, flavonoids, and - for officinal plants - also terpenoids, together with the antiradical activity (FRAP assays). In addition, to better typify the phytocomplexes of these landraces, HPLC-DAD and GC-MS analyses were carried out. In general, officinal plants showed higher values of nutraceutical compounds and related bioactivity with respect to fruit species. The data showed how different accessions of the same species had different phytochemical profiles, according to the sampling area and the year of collection, suggesting a role for both genetic and environmental factors in determining the observed results. Therefore, the final goal of this research was also to find a possible correlation between environmental factors and nutraceutics. The greatest correlation was found in valerian, where a lower water intake seemed to lead to a higher accumulation of antioxidants, and in plum, where the flavonoid content correlated positively with high temperatures. All these outcomes contribute at valorising Basilicata landraces for their aptitude to be high-quality foods and, at the same time, promoting the preservation of the agrobiodiversity for this region.

Changes in Content of Bioactive Compounds and Antioxidant Activity Induced in Needles of Different Half-Sib Families of Norway Spruce (Picea abies (L.) H. Karst) by Seed Treatment with Cold Plasma

In order to ensure sufficient food resources for a constantly growing human population, new technologies (e.g., cold plasma technologies) are being developed for increasing the germination and seedling growth without negative effects on the environment. Pinaceae species are considered a natural source of antioxidant compounds and are valued for their pharmaceutical and nutraceutical properties. In this study, the seeds of seven different Norway spruce half-sib families were processed for one or two minutes with cold plasma (CP) using dielectric barrier discharge (DBD) plasma equipment. At the end of the second vegetation season, the total flavonoid content (TFC), DPPH (2,2- diphenyl-1-picryl-hydrazyl-hydrate), and ABTS (2,2’-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid)) antioxidant activity, and the amounts of six organic acids (folic, malic, citric, oxalic, succinic, and ascorbic) were determined in the needles of different half-sib families of Norway spruce seedlings. The results show that the TFC, antioxidant activity, and amounts of organic acids in the seedling needles depended on both the treatment duration and the genetic family. The strongest positive effect on the TFC was determined in the seedlings of the 477, 599, and 541 half-sib families after seed treatment with CP for 1 min (CP1). The TFC in these families increased from 118.06 mg g⁻¹ to 312.6 mg g⁻¹ compared to the control. Moreover, seed treatment with CP1 resulted in the strongest increase in the antioxidant activity of the needles of the 541 half-sib family seedlings; the antioxidant activity, determined by DPPH and ABTS tests, increased by 30 and 23%, respectively, compared to the control. The obtained results indicate that the CP effect on the amount of organic acids in the needles was dependent on the half-sib family. It was determined that treatment with CP1 increased the amount of five organic acids in the needles of the 541 half-sib family seedlings. The presented results show future possibilities for using cold plasma seed treatment in the food and pharmacy industries.

Oregano Phytocomplex Induces Programmed Cell Death in Melanoma Lines via Mitochondria and DNA Damage

Plant secondary metabolites possess chemopreventive and antineoplastic properties, but the lack of information about their exact mechanism of action in mammalian cells hinders the translation of these compounds in suitable therapies. In light of this, firstly, Origanum vulgare L. hydroalcoholic extract was chemically characterized by spectrophotometric and chromatographic analyses; then, the molecular bases underlying its antitumor activity on B16-F10 and A375 melanoma cells were investigated. Oregano extract induced oxidative stress and inhibited melanogenesis and tumor cell proliferation, triggering programmed cell death pathways (both apoptosis and necroptosis) through mitochondria and DNA damage. By contrast, oregano extract was safe on healthy tissues, revealing no cytotoxicity and mutagenicity on C2C12 myoblasts, considered as non-tumor proliferating cell model system, and on Salmonella strains, by the Ames test. All these data provide scientific evidence about the potential application of this food plant as an anticancer agent in in vivo studies and clinical trials.

Antioxidants with two faces toward cancer

Antioxidants are essential in preventing the formation and suppressing the activities of reactive nitrogen and oxygen species. The aim of this study was to review the role of antioxidants in cancer development or prevention. Antioxidants are believed to prevent and treat various types of malignancies. Currently, natural antioxidant compounds have been generally consumed to prevent and treat cancers. Certainly, phenolic compounds extracted from medicinal plants have opened a new prospect with respect to the prevention and treatment of cancers due to having antioxidant characteristics. However, some recently published studies have revealed that antioxidant compounds do not indicate absolute anti-tumor properties. Some antioxidants are helpful in cancer initiation and progression. Taken together, antioxidants demonstrate a two-faced nature toward cancer. However, it is required to conduct further cell culture and in vivo studies to confirm the exact role of antioxidants and then use them for efficient cancer treatments.

2'-Hydroxyflavanone inhibits the progression of pancreatic cancer cells and sensitizes the chemosensitivity of EGFR inhibitors via repressing STAT3 signaling

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal malignancies, and chemotherapy is still an important treatment. It is urgent to develop new medicines because of the limitation and side effects of chemotherapy. 2'-Hydroxyflavanone (2HF) is a citrus-bioflavonoid that is considered to have anti-cancer efficacy. Compared to human pancreatic ductal epithelial cells hTERT-HPNE, more significant growth-inhibitory effects were seen in PDAC cells BxPC-3 and MIA PaCa-2. We showed that apoptosis was induced and that the cell cycle was arrested when cells were treated with 2HF. The expression of the molecular proteins cleaved PARP, cleaved Caspase3, Bax, Bcl-2, CyclinD1, and p27 changed correspondingly. Also, we observed anti-metastatic effects and changes in MMP9, E-cadherin, N-cadherin and Vimentin when cells were treated with a low dose of 2HF. Suppression of STAT3 and EGFR phosphorylation was also identified as a result of treatment with a combination of 2HF and EGFR inhibitors. The in vivo antitumor effects in KPC mice were consistent with those observed in vitro. 2HF has impactful anti-cancer efficacy and sensitizes human pancreatic cancer cells to EGFR inhibitors through the inhibition of STAT3.

Simultaneous Optimization of Ultrasound-Assisted Extraction for Flavonoids and Antioxidant Activity of Angelica keiskei Using Response Surface Methodology (RSM)

Angelica keiskei Koidzumi (A. keiskei), as a Japanese edible herbal plant, enjoys a variety of biological activities due to the presence of numerous active compounds, especially flavonoids. This study aims for the optimization of ultrasound-assisted extraction (UAE) for flavonoids in A. keiskei and their antioxidant activity by using the response surface methodology (RSM). Single-factor experiments and a four-factor three-level Box-Behnken design (BBD) were performed to explore the effects of the following parameters on flavonoid extraction and antioxidant activity evaluation: ultrasonic temperature (X1), ultrasonic time (X2), ethanol concentration (X3) and liquid-solid ratio (X4). The optimum conditions of the combination of total flavonoid content (TFC), 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging capacity (DPPH-RSC) and ferric-reducing antioxidant power (FRAP) were as follows: X1 = 80 °C, X2 = 4 min, X3 = 78%, X4 = 35 mL/g, respectively. The experimental results provide a theoretical basis for the extensive utilization of A. keiskei and flavonoids extraction from A. keiskei as a potential source of antioxidants.

Plant defense factors involved in Olea europaea resistance against Xylella fastidiosa infection

Olive quick decline syndrome (OQDS) is a dangerous plant disease, caused by the bacterium Xylella fastidiosa, which targets olive (Olea europaea). Since field observations suggested that some olive cultivars (i.e. Leccino) were more resistant to OQDS than others (i.e. Cellina di Nardò), the plant defense strategies adopted by olive to contrast X. fastidiosa infection were investigated. In the present study, ELISA and genetic approaches were used to confirm plant infection, while microbial colonization mechanism and distribution in host plant tissues and reactive oxygen species (ROS) levels were examined by light, scanning electron and confocal microscopy analyses. Spectrophotometric and chromatographic techniques were performed to measure secondary metabolites content and qPCR assay was carried out for monitoring plant gene expression variation. Our analysis showed that X. fastidiosa caused accumulation of ROS in Leccino samples compared to Cellina di Nardò. Moreover, the infection induced the up-regulation of defense-related genes, such as NADPH oxidase, some protein kinases, pathogen plant response factors and metabolic enzymes. We also found that Leccino plants enhanced the production of specific antioxidant and antimicrobial molecules, to fight the pathogen and avoid its spreading into xylem vessels. We provided new information on OQDS resistance mechanism applied by Leccino cultivar. In particular, we evidenced that high concentrations of ROS, switching on plant defence signalling pathways, may represent a key factor in fighting X. fastidiosa infection.

Solvent based optimization for extraction and stability of thymoquinone from Nigella sativa Linn. and its quantification using RP-HPLC

The Nigella sativa pharmacological properties are mainly ascribed to its volatile oil, of which thymoquinone is an important bioactive component. Surprisingly, till date, no standard formulation or thymoquinone rich N. sativa extract is under clinical use probably due to its poor extraction and lesser stability in the already used solvents. In the present investigation solubility, extraction, percent composition and total antioxidant activity from the seeds of N. sativa was explored using five solvents. An HPLC method was standardized in an isocratic system (C-18 column, flow rate of 1.0 ml/min, mobile phase-water:methanol: 30:70, detection wavelength-254 nm, retention time-8.77 min) for quantification of thymoquinone. To further confirm the presence of thymoquinone in the respective extracts absorbance spectra analysis has been carried out and compared with pure thymoquinone. Additionally total antioxidant activity of Nigella sativa extracts has been evaluated using ascorbic acid as standard. Our results showed maximum percentage yield in aqueous extract while methanol having the least yield and the ethanol, benzene and hexane extracts exhibited moderate yields. A linear standard calibration curve of thymoquinone showed R² as 0.999 and % RSD as 7.166. The HPLC analysis revealed maximum percentage composition of thymoquinone in the benzene extract, whereas in the hexane and methanol extracts the content was less. Aqueous and ethanol extracts displayed insignificant thymoquinone content. Absorbance spectra analysis confirms the presence of thymoquinone peak in the benzene, hexane and methanol extracts while aqueous and ethanol extracts showed minimal absorbance. Maximum total antioxidant activity was observed in the aqueous extract while minimum was observed in the methanolic extract. Weak positive (+ 0.3676) correlation was established between percent composition of thymoquinone and antioxidant activity among different extracts indicating that thymoquinone may not be the only factor for antioxidant activity, but other phytochemicals might also contribute. However, we for the first time demonstrated that the benzene extract of N. sativa has better solubility and percent composition of thymoquinone as compared to other solvents. It can be concluded that the solubility, differential composition of bioactive components among these extracts may have diverse effects on the total antiradical activity. Thus, our study provides insights on optimization and standardization of bioactive rich formulation of N. sativa.

From Robinia pseudoacacia L. nectar to Acacia monofloral honey: biochemical changes and variation of biological properties

BACKGROUND

Robinia pseudoacacia L. nectar and its derivative monofloral honey were systematically compared in this study, to understand how much the starting solution reflected the final product, after re-elaboration by Apis mellifera ligustica Spinola.

RESULTS

Subjected to dehydration in the hive, nectar changed in its water and sugar content when transformed into honey, as physicochemical and gas chromatographic-mass spectrometric analyses revealed. Spectrophotometric measurements and characterization by high-performance liquid chromatography-diode array detection of 18 plant molecules demonstrated honey to be richer than nectar in secondary metabolites. For the first time, the hypothesis of the existence of a nectar redox cycle in R. pseudoacacia was reported, as previously described for Nicotiana sp., based on 1D-protein profiles, western blot analysis and detection of H₂ O₂ and ascorbate. The bioactivity of both matrices was also investigated. Antiradical in vitro tests showed that Acacia honey was more antioxidant than nectar, which was even able to induce oxidative stress directly in a eukaryotic cell system. Antimicrobial assays demonstrated that nectar was bacteriostatic, due to H₂ O₂ activity, whereas honey was even bactericidal.

CONCLUSION

All these data support the ecological role of nectar and honey in nature: protection of the gynoecium from pathogens and preservation from degradative processes, respectively. © 2018 Society of Chemical Industry.

Botanical influence on phenolic profile and antioxidant level of Italian honeys

Honeybees directly transfer plant compounds from nectar into honey. Each plant species possesses a specific metabolic profile, the amount and the typology of plant molecules that may be detected in honey vary according to their botanical origin. Aim of the present work was the spectrophotometrical determination of concentration ranges of simple phenols and flavonoids in 460 several Italian monofloral honeys, in order to individuate specific intervals of plant metabolites for each typology of honey. Moreover, an LC-MS analysis was performed to determine amount of various secondary metabolites in the samples, with the purpose to use them as potential molecular markers in support to honey melissopalynological classification. As plant molecules have a strong reducing power, the antioxidant activity of the honeys was evaluated by two antiradical assays, DPPH and FRAP. The free radical scavenging effect of each monofloral group was correlated to the concentration of simple phenols and flavonoids, with the aim to deduce the existence of possible relationships between these parameters. In conclusion, dark honeys (Castanea sativa, honeydew, Erica sp. and Eucalyptus sp.) appeared to be the richest in secondary metabolites and, consequently, showed higher antioxidant activity. However, all analyzed monofloral honeys showed to be good sources of antioxidants.

Hydroalcoholic extract of Spartium junceum L. flowers inhibits growth and melanogenesis in B16-F10 cells by inducing senescence

BACKGROUND

Ultraviolet light exposure generates, in human tissues, radical species, which represent the main cause of photo-aging, DNA damage and skin cancer onset. On the other hand, Mediterranean plants, being continuously subjected to high solar radiation levels, are naturally adapted to take on this type of abiotic stress, thanks to the production of antioxidant secondary metabolites. For these reasons, several plant extracts were documented to be excellent antineoplastic drugs.

PURPOSE

We investigated the potential antitumor activity of the flower extract obtained by Spartium junceum L., a Mediterranean shrub, correlating it with the plant metabolic profile.

STUDY DESIGN

After selecting the best extraction method to obtain as more secondary metabolites as possible from S. junceum flowers, we characterized the extract metabolic content. Then, by in vitro analyses, the antioxidant profile and the antineoplastic activity on B16-F10 murine melanoma cell of our extract were investigated.

METHODS

Spectrophotometric assays, HPLC-DAD and GC-MS analyses provided us information about flower extract composition and antioxidant activity. MTT assay and Trypan Blue exclusion test were performed to assess the extract toxicity and the viability, after treatments, of B16-F10 cancer cells and of C2C12 murine myoblasts. In vitro experiments (i.e. cytofluorimetry, protein analysis and qPCR) allowed us to analyze the effect of the plant extract on B16-F10 cell redox state, melanogenesis and cell cycle. Senescence induction was investigated by using a specific kit.

RESULTS

We observed that the hydroalcoholic extract of S. junceum flowers (HFE) strongly inhibited B16-F10 murine melanoma cell proliferation, while just a feeble effect was observed on C2C12 murine myoblasts. Moreover, we found that HFE exerted a pro-oxidant activity on melanoma cells, inhibited melanogenesis and caused cell cycle arrest in G2/M phase, inducing senescence. These anti-cancer properties of HFE could be related to the rich metabolic profile of the extract that we characterized by HPLC-DAD and GC-MS analyses.

CONCLUSION

This evidence suggests that S. junceum phytocomplex can be used as a selective, nontoxic, economic and easily available anticancer drug.

Boldine Improves Kidney Damage in the Goldblatt 2K1C Model Avoiding the Increase in TGF-β

Boldine, a major aporphine alkaloid found in the Chilean boldo tree, is a potent antioxidant. Oxidative stress plays a detrimental role in the pathogenesis of kidney damage in renovascular hypertension (RVH). The activation of the renin-angiotensin system (RAS) is crucial to the development and progression of hypertensive renal damage and TGF-β is closely associated with the activation of RAS. In the present study, we assessed the effect of boldine on the progression of kidney disease using the 2K1C hypertension model and identifying mediators in the RAS, such as TGF-β, that could be modulated by this alkaloid. Toward this hypothesis, rats (n = 5/group) were treated with boldine (50 mg/kg/day, gavage) for six weeks after 2K1C surgery (pressure ≥ 180 mmHg). Kidney function was evaluated by measuring of proteinuria/creatininuria ratio (U prot/U Crea), oxidative stress (OS) by measuring thiobarbituric acid reactive substances (TBARS). The evolution of systolic blood pressure (SBP) was followed weekly. Alpha-smooth muscle actin (α-SMA) and Col III were used as markers of kidney damage; ED-1 and osteopontin (OPN) were used as markers of inflammation. We also explored the effect in RAS mediators, such as ACE-1 and TGF-β. Boldine treatment reduced the UProt/UCrea ratio, plasma TBARS, and slightly reduced SBP in 2K1C hypertensive rats, producing no effect in control animals. In 2K1C rats treated with boldine the levels of α-SMA, Col III, ED-1, and OPN were lower when compared to 2K1C rats. Boldine prevented the increase in ACE-1 and TGF-β in 2K1C rats, suggesting that boldine reduces kidney damage. These results suggest that boldine could potentially be used as a nutraceutic.

Overexpression of BraLTP2, a Lipid Transfer Protein of Brassica napus, Results in Increased Trichome Density and Altered Concentration of Secondary Metabolites

Plant non-specific lipid transfer proteins (nsLTPs) belong to a large multigene family that possesses complex physiological functions. Trichomes are present on the aerial surfaces of most plants and include both glandular secretory hairs and non-glandular hairs. In this study, BraLTP2 was isolated from Brassica rapa (B. rapa) and its function was characterized in the important oilseed crop Brassica napus (B. napus). B. rapa lipid transfer protein 2 (BraLTP2) belongs to the little-known Y class of nsLTPs and encodes a predicted secretory protein. In Pro_BraLTP2::GUS (β-glucuronidase) transgenic plants, strong GUS activity was observed in young leaves and roots, while low activity was observed in the anther. It is noteworthy that strong GUS activity was observed in trichomes of the first four leaves of 4-week-old and 8-week-old seedings, however, it disappeared in 12-week-old seedings. In transgenic plants expressing a BraLTP2::GFP (green fluorescent protein) fusion protein, GFP fluorescence localized in the extracellular space of epidermal cells and trichomes. Overexpression of BraLTP2 in B. napus caused an increase in trichome number and altered the accumulation of secondary metabolites in leaves, including 43 upregulated secondary metabolites. Moreover, transgenic plants showed significantly increased activities of antioxidant enzymes. These results suggest that BraLTP2, a new nsLTP gene, may play a role in trichome development and the accumulation of secondary metabolites.

Anti-photoaging potential of propolis extract in UVB-irradiated human dermal fibroblasts through increasing the expression of FOXO3A and NGF genes

Propolis is a resinous compound that has been widely used in folk medicine. Different biological activities and therapeutic applications of propolis have been studied before. However, the effects of propolis on longevity-associated genes expression in the prevention of skin photoaging still remained unclear. Therefore in this study the protective effects of propolis on the expressions of two longevity-associated genes, FOXO3A and NGF genes, against UVB-induced photoaging in human dermal fibroblasts (HDF) were investigated. Propolis extract demonstrated a concentration-dependent free radical scavenging activity that was determined by 2, 2-diphenyl-1-picrylhydrazyl (DPPH) assay. Also, Folin-Ciocalteu method was used to measure the total phenolic content of the extract. The viability of HDF cells was decreased gradually with increasing UVB radiation doses and 248mJ/cm² was selected as the sub-cytotoxic dose. Pre-treatment with propolis extract increased the viability of UVB-irradiated human dermal fibroblasts and decreased the number of β-galactosidase positive cells as senescent cells among them. It also increased the expression of FOXO3A and NGF genes in irradiated and non-irradiated cells. Consequently, these findings suggest that propolis extract has anti-photoaging potential and this property, in addition to its strong antioxidant activity, may be due to its effects on upregulation of longevity-associated genes.

Bioactivity-based antioxidative components screening and evaluation in grape seed proanthocyanidin extract

Grape seed proanthocyanidin extract (GSPE), a type of functional food, possesses potent antioxidant activity. In this study, GSPE protected human embryonic kidney 293 (HEK 293) cells from H₂O₂-induced cell injury and oxidative stress in a dose-dependent manner. The key effective constituents that exerted the most potent antioxidative activity in GSPE were screened by using a modified ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry (UPLC-Q/TOF MS) integrated 2,2'-azinobis(3-ethylbenzothiazoline)-6-sulfonic acid (ABTS) radical cation antioxidative activity analysis system. Two compounds, which were presumed to be Procyanidin B2 and Procyanidin C2, showed obvious antioxidant activity. H₂O₂ scavenging effect of Procyanidin B2 in HEK 293 cells was visualized in situ by a molecular imaging technique via a novel N-borylbenzyloxycarbonyl-3,7-dihydroxyphenoxazine (NBCD) fluorescent probe to detect levels of H₂O₂. In conclusion, the application of UPLC-Q/TOF MS integrated modified ABTS radical cation antioxidative activity analysis system and NBCD fluorescent probe successfully screened out and confirmed the antioxidative components from GSPE.

Evaluation of three pumpkin species: correlation with physicochemical, antioxidant properties and classification using SPME-GC-MS and E-nose methods

To ascertain the most discriminant variables for three pumpkin species principal component analysis (PCA) was performed. Twenty-four parameters (pH, conductivity, sucrose, glucose, total soluble solids, L*, a*, b*, individual weight, edible rate, firmness, citric acid, fumaric acid, l-ascorbic acid, malic acid, PPO activity, POD activity, total flavonoids, vitamin E, total phenolics, DPPH, FRAP, β-carotene, and aroma) were considered. The studied pumpkin species were Cucurbita maxima, Cucurbita moschata, and Cucurbita pepo. Three pumpkin species were classified by PCA based on aroma, physicochemical and antioxidant properties because the sum of PC1 and PC2 were both greater than 85% (85.06 and 93.64% respectively). Results were validated by the PCA and showed that PPO activity, total flavonoid, sucrose, glucose, TSS, a*, pH, malic acid, vitamin E, DPPH, FRAP and β-carotene, and aroma are highly useful parameters to classify pumpkin species.

In Vitro Antioxidant Activities of Enzymatic Hydrolysate from Schizochytrium sp. and Its Hepatoprotective Effects on Acute Alcohol-Induced Liver Injury In Vivo

Schizochytrium protein hydrolysate (SPH) was prepared through stepwise enzymatic hydrolysis by alcalase and flavourzyme sequentially. The proportion of hydrophobic amino acids of SPH was 34.71%. The molecular weight (MW) of SPH was principally concentrated at 180–3000 Da (52.29%). SPH was divided into two fractions by ultrafiltration: SPH-I (MW < 3 kDa) and SPH-II (MW > 3 kDa). Besides showing lipid peroxidation inhibitory activity in vitro, SPH-I exhibited high DPPH and ABTS radicals scavenging activities with IC₅₀ of 350 μg/mL and 17.5 μg/mL, respectively. In addition, the antioxidant activity of SPH-I was estimated in vivo using the model of acute alcohol-induced liver injury in mice. For the hepatoprotective effects, oral administration of SPH-I at different concentrations (100, 300 mg/kg BW) to the mice subjected to alcohol significantly decreased serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities and hepatic malondialdehyde (MDA) level compared to the untreated mice. Besides, SPH-I could effectively restore the hepatic superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) activities and glutathione (GSH) level. Results suggested that SPH was rich in biopeptides that could be exploited as antioxidant molecules against oxidative stress in human body.

Antioxidant Capacities of Fractions of Bamboo Shaving Extract and Their Antioxidant Components

This research was conducted for evaluation of antioxidant activities of four fractions from bamboo shavings extract (BSE) and their antioxidant components. The antioxidant capacities of BSE and four fractions on ABTS, DPPH, FRAP and total antioxidant capacity assays exhibited the following descending order: DF > n-butanol fraction (BF) > BSE ≈ ethyl acetate fraction (AF) > water fraction (WF). Among the identified phenolic compounds, caffeic acid exhibited the highest antioxidant capacities on DPPH, FRAP and total antioxidant capacity assays. An extremely significant positive correlation between the antioxidant activities with the contents of total flavonoids, total phenolic acids, or total phenolics was observed in this study. The result indicated that the bamboo shaving extract and its solvent fractions could act as natural antioxidants in light of their potent antioxidant activities.

Quality Control of Gamma Irradiated Dwarf Mallow (Malva neglecta Wallr.) Based on Color, Organic Acids, Total Phenolics and Antioxidant Parameters

This study addresses the effects of gamma irradiation (1, 5 and 8 kGy) on color, organic acids, total phenolics, total flavonoids, and antioxidant activity of dwarf mallow (Malva neglecta Wallr.). Organic acids were analyzed by ultra fast liquid chromatography (UFLC) coupled to a photodiode array (PDA) detector. Total phenolics and flavonoids were measured by the Folin-Ciocalteu and aluminium chloride colorimetric methods, respectively. The antioxidant activity was evaluated based on the DPPH(•) scavenging activity, reducing power, β-carotene bleaching inhibition and thiobarbituric acid reactive substances (TBARS) formation inhibition. Analyses were performed in the non-irradiated and irradiated plant material, as well as in decoctions obtained from the same samples. The total amounts of organic acids and phenolics recorded in decocted extracts were always higher than those found in the plant material or hydromethanolic extracts, respectively. The DPPH(•) scavenging activity and reducing power were also higher in decocted extracts. The assayed irradiation doses affected differently the organic acids profile. The levels of total phenolics and flavonoids were lower in the hydromethanolic extracts prepared from samples irradiated at 1 kGy (dose that induced color changes) and in decocted extracts prepared from those irradiated at 8 kGy. The last samples also showed a lower antioxidant activity. In turn, irradiation at 5 kGy favored the amounts of total phenolics and flavonoids. Overall, this study contributes to the understanding of the effects of irradiation in indicators of dwarf mallow quality, and highlighted the decoctions for its antioxidant properties.

Biological Activity of Vegetal Extracts Containing Phenols on Plant Metabolism

The influence of vegetal extracts derived from red grape, blueberry fruits and hawthorn leaves on Zea mays L. plant growth and the activity of phenylalanine ammonia-lyase (PAL), a key enzyme of the phenylpropanoid pathway, was investigated in laboratory experiments. The extracts were characterized using FT-IR and Raman spectroscopies in order to obtain a pattern of the main functional groups. In addition, phenols content was determined by HPLC, whereas the content of indoleacetic acid and isopentenyladenosine hormones was determined by ELISA test and the auxin and gibberellin-like activities by plant-bioassays. The treated maize revealed increased root and leaf biomass, chlorophyll and sugars content with respect to untreated plants. Hawthorn, red grape skin and blueberry at 1.0 mL/L induced high p-coumaric content values, whilst hawthorn also showed high amounts of gallic and p-hydroxybenzoic acids. PAL activity induced by hawthorn at 1.0 mL/L had the highest values (11.1-fold UNT) and was strongly and linearly related with the sum of leaf phenols. Our results suggest that these vegetal extracts contain more than one group of plant-promoting substances.

Inhibitory Effect of Dried Pomegranate Concentration Powder on Melanogenesis in B16F10 Melanoma Cells; Involvement of p38 and PKA Signaling Pathways

Plants rich in antioxidant substances may be useful for preventing skin aging. Pomegranates, containing flavonoids and other polyphenolic compounds, are widely consumed due to their beneficial properties. We examined the underlying mechanisms of dried pomegranate concentrate powder (PCP) on melanin synthesis in B16F10 melanoma cells. The antioxidant effects of PCP were determined by measuring free radical scavenging capacity and transcript levels of antioxidant enzymes. To explore the inhibitory effects of PCP on melanin synthesis, we measured tyrosinase activity and melanin content in α-melanocyte stimulating hormone (α-MSH)-stimulated B16F10 cells. In addition, the levels of tyrosinase-related protein-1 (TRP-1), TRP-2, tyrosinase, and microphthalmia-associated transcription factor (MITF) expression were determined by Western blotting. Changes in the phosphorylation status of protein kinase A (PKA), cAMP response element-binding protein (CREB), mitogen-activated protein kinases (MAPKs), phosphatidylinositol 3-kinase (PI3K), serine/threonine kinase Akt, and glycogen kinase 3β (GSK3β) were also examined. The free radical scavenging activity of PCP increased in a dose-dependent manner. In PCP-treated B16F10 cells, transcript levels of glutathione peroxidase-1 (GPx-1) were increased compared with α-MSH-stimulated cells. In addition, PCP led to the down-regulation of phospho-p38, phospho-PKA, phospho-CREB, phospho-GSK3β, MITF, and TRP-1 compared with α-MSH-stimulated B16F10 cells. We believe this effect may be associated with PCP activity, which leads to the inhibition of melanin production and tyrosinase activity. These results suggest that PCP decreases tyrosinase activity and melanin production via inactivation of the p38 and PKA signaling pathways, and subsequently decreases phosphorylation of CREB, MITF, and melanogenic enzymes. These observations provided new insights on the molecular mechanisms of the skin-whitening property of PCP.