Antioxidant Capacity and Phenolics Content of Apricot (<Emphasis Type="Italic">Prunus armeniaca</Emphasis> L.) Kernel as a Function of Genotype

Fourteen apricot genotypes grown under similar cultural practices in Trans-Himalayan Ladakh region were studied to find out the influence of genotype on antioxidant capacity and total phenolic content (TPC) of apricot kernel. The kernels were found to be rich in TPC ranging from 92.2 to 162.1 mg gallic acid equivalent/100 g. The free radical-scavenging activity in terms of inhibitory concentration (IC₅₀) ranged from 43.8 to 123.4 mg/ml and ferric reducing antioxidant potential (FRAP) from 154.1 to 243.6 FeSO₄.7H₂O μg/ml. A variation of 1–1.7 fold in total phenolic content, 1–2.8 fold in IC₅₀ by 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay and 1–1.6 fold in ferric reducing antioxidant potential among the examined kernels underlines the important role played by genetic background for determining the phenolic content and antioxidant potential of apricot kernel. A positive significant correlation between TPC and FRAP (r = 0.671) was found. No significant correlation was found between TPC and IC₅₀; FRAP and IC₅₀; TPC and physical properties of kernel. Principal component analysis demonstrated that genotypic effect is more pronounced towards TPC and total antioxidant capacity (TAC) content in apricot kernel while the contribution of seed and kernel physical properties are not highly significant.     

Antioxidant and Antiproliferative Activity of <Emphasis Type="Italic">Diospyros lotus</Emphasis> L. Extract and Isolated Compounds

The object of the study was to determine the chemical composition of Diospyros lotus L. extract and their antioxidant and antiproliferative properties. Eight compounds were isolated from D. lotus and identified as gallic acid, methylgallate, ellagic acid, kaempferol, quercetin, myricetin, myricetin 3-O-β-glucuronide, and myricetin-3-O-α-rhamnoside. D. lotus extract tested in different in vitro systems (DPPH, ABTS, FRAP, and Fe²⁺ chelating activity assay) showed significant antioxidant activity. The potential antiproliferative properties of D. lotus extract and isolated compounds against nine human cancer cell lines such as COR-L23, CaCo-2, C32, ACHN, A375, A549, Huh-7D12, MCF-7, and LNCaP were investigated in vitro by SRB assay. D. lotus extract demonstrated the highest inhibitory activity against COR-L23 with an IC₅₀ value of 12.2 μg/ml. Among identified hydrolysable tannins, ellagic acid evidenced strong antiproliferative activity against both C32 and A375 cells with IC₅₀ values of 0.8 and 4.1 μg/ml, respectively. Interesting results were observed, also, with gallic acid that showed the highest cytotoxic activity against CaCo-2 (IC₅₀ 2.6 μg/ml). Overall, the results of this study suggest that D. lotus displays a good antioxidant activity and has antiproliferative effects. Both activities are related to identified phenolic compounds.     

Determination of the Antimicrobial and Antioxidative Properties and Total Phenolics of Two “Endemic” Lamiaceae Species from Turkey: <Emphasis Type="Italic">Ballota rotundifolia</Emphasis> L. and <Emphasis Type="Italic">Teucrium chamaedrys</Emphasis> C. Koch

This study was designed to examine the in vitro antimicrobial and antioxidant activities and the amount of total phenolics of the methanol extracts of Ballota rotundifolia L. and Teucrium chamaedrys C. Koch. In the case of antimicrobial activity tests, polar sub-fractions of the methanol extracts of plant species exhibited weakest antimicrobial activity when compared with the non-polar ones. While, non-polar sub-fraction of B. rotundifolia showed moderate activity against A. lwoffii, C. perfringens and the yeasts, T. chamaedrys performed excellent activity pattern against all of the tested microorganisms. The sub-fractions were also screened for their possible antioxidant activities by two complementary tests, namely DPPH free radical-scavenging and β-carotene/linoleic acid assays. Non-polar extracts of the plant species remained inactive in both test systems. On the other hand polar extracts showed remarkable antioxidant activities. In DPPH system, free radical scavenging effect of T. chamaedrys was measured as 18.00 ± 1.42 μg.mg⁻¹. It is extremely important to point out that, polar sub-fraction of T. chamaedrys is found as effective as the positive control BHT. Non-polar sub-fraction of T. chamaedrys found to have the highest total phenolic amount (97.12 ± 1.28 μg/mg). Results obtained from this experiment confirm the relationship between the amount of phenolics and biological activities.     

Effects of Pressurized Low Polarity Water Extraction Parameters on Antioxidant Properties and Composition of Cow Cockle Seed Extracts

Antioxidant activity of pressurized low polarity water (PLPW) extracts of cow cockle seed and extraction residues were determined using DPPH, ABTS, and FRAP assays. The effect of extraction conditions (temperature (125, 150 and 175 °C) and time) on the antioxidant activity and the relationship amongst the antioxidant activity and extract composition (total phenolics and saponin content) were determined. The antioxidant activity of PLPW extracts increased with extraction temperature. Increasing activity with time was also observed at 175 °C. PLPW extraction residues had the highest activity suggesting antioxidant compounds were not completely extracted by PLPW. Antioxidant activity correlated well with total phenolics content of samples (R ² ≥ 0.94), however no correlation was observed with the saponin content. A strong correlation was observed between the antioxidant activity values obtained using different methods (R ² ≥ 0.94). These results point to the potential of PLPW extraction as a method to modify the activity of biological materials for the production of customized extracts.     

Preparation and evaluation of antioxidant capacity of Jackfruit (Artocarpus heterophyllus Lam.) wine and its protective role against radiation induced DNA damage

Jackfruit is an underutilized edible fruit in the tropics and subtropics. The aim of this study was to produce wine from jackfruit pulp and to evaluate the total phenolic and flavonoid contents and antioxidant properties of the wine. The ability of scavenging free radicals was measured using 2,2-diphenyl-1-picrylhydrazyl (DPPH), ferric reducing antioxidant assay (FRAP), N, N-dimethyl-p-phenylendiamine (DMPD) and nitric oxide (NO) scavenging assays. Experimental results indicated that jackfruit wine was effective in DPPH radical scavenging (69.44 ± 0.34%), FRAP (0.358 optical density value, O.D.), DMPD (78.45 ± 0.05%) and NO (62.46 ± 0.45%) capacity. By the analysis of the high performance liquid chromatography coupled to diode array detector (HPLC-DAD), two phenolic compounds namely gallic acid and protocatechuic acid were identified. The jackfruit wine was also able to protect H₂O₂ + UV radiation and γ-radiation (100 Gy) induced DNA damage in pBR322 plasmid DNA. The antioxidant and DNA damage protecting properties of jackfruit wine confirmed health benefits when consumed and could become a valuable source of antioxidant rich neutraceuticals. Additionally, the wine could be a commercially valuable by-product for the jackfruit growers.     

Antioxidative and Antigenotoxic Activity of Extracts from Cosmos (Cosmos bipinnatus) Flowers

The Cosmos bipinnatus has been used in a traditional herbal remedy for various diseases such as jaundice, intermittent fever, and splenomegaly. The present study describes the preliminary evaluation of antioxidant activities and antigenotoxic effect of Cosmos bipinnatus flowers according to four different colors (white, pink, orange, and violet). The antioxidants properties were evaluated by determining TPC, DPPH RSA, ABTS RSA, and RP. The highest TPC of methanolic CFE (at concentration of 1 mg/ml) showed in violet colored CF (1,013 μM), and IC₅₀ of DPPH RSA, ABTS RSA, and RP were also the lowest in violet colored CFE with values of 0.61, 1.48, and 0.82 mg/ml, respectively. The antigenotoxic effect of the CFE on DNA damage induced by H₂O₂ in human leukocytes was evaluated by Comet assay. Pretreatments with CFE produced significant reductions in oxidative DNA damage at the concentration of 500 μg/ml, except for violet colored CFE. The ED₅₀ value of white colored CFE has shown the highest inhibition (0.40 mg/ml) on H₂O₂ induced DNA damage, followed by orange > pink > violet color. These results suggested that Cosmos bipinnatus has significant antioxidant activity and protective effect against oxidative DNA damage.     

Antioxidant activity and phenolic content of chestnut (Castanea sativa) shell and eucalyptus (Eucalyptus globulus) bark extracts

Chestnut (Castanea sativa) shell and eucalyptus (Eucalyptus globulus) bark, waste products of the food and wood industries, respectively, were analysed as potential sources of antioxidant compounds. The extraction yield, the antioxidant activity and total phenols content of the extracts were greater in chestnut shell than in eucalyptus bark for most of the extraction conditions essayed. Extraction of chestnut shell with a 2.5% Na₂SO₃ aqueous solution led to the highest extraction yield, 25.6%, total phenols, 13.4 g gallic acid equivalent/100 g oven-dried shell, and FRAP antioxidant activity, 80.7 mmol ascorbic acid equivalent/100 g oven-dried shell. Extraction with methanol:water (50:50, v/v) provided the best results for eucalyptus bark. The antioxidant activity and the total phenols content of the extracts had a positive linear correlation. FTIR spectroscopy confirmed the higher content of phenolic compounds in chestnut shell extracts compared to eucalyptus bark extracts. Chestnut shell extracts were characterized by the presence of high molecular weight species whereas lower molecular weight species were predominant in eucalyptus bark extracts.     

Antioxidant Properties and Evaluation of Phytochemical Composition of Salvia verbenaca L. Extracts at Different Developmental Stages

Changes in the contents and composition of polyphenolics and resulting antioxidant activities of S. verbenaca by-products were investigated at three phenological stages (flowering, early fruiting and late fruiting stages). The highest accumulation of total phenolics was detected at the flowering stage (58.36 mg GAE/g DW). HPLC analysis of methanolic extracts showed the prevalence of methyl carnosate (821.45–919.82 μg/g DW) and rosmarinic acid (544.51–649.26 μg/g DW). Phenolic diterpenes (1056.90–1148.42 μg/g DW) was the most represented class of compounds. Three complementary tests namely, DPPH^? (IC₅₀ value, 49.22 μg/mL) and ABTS^?+-radical scavenging assays (146.86 μM TE/mg) and FRAP reducing power test (188.93 mM Fe(II)/mg) were used to evaluate the antioxidant capacity and showed the best performance at the early fruiting period. The current study evidenced the significant effect of phenophase on antioxidants and contributed to valorize S. verbenaca extracts as a source of functional phenolic compounds.

     

Antioxidant Activities of Four Edible Seaweeds from the Southern Coast of Thailand

The aqueous extracts of four marine algae, Caulerpa racemosa var. macrophysa, Gracilaria tenuistipitata var. tenuistipitata, Sargassum sp., and Ulva lactuca, from the coastal areas in Southern Thailand, were prepared by boiling dried seaweed powder in water for 3 h, and by autoclaving each sample at 120 °C for 3 h. They were then freeze-dried and evaluated for their antioxidant activities using DPPH (1, 1-diphenyl-2-picrylhydrazyl), hydroxyl radical (OH^•) and superoxide anion (O₂^•−) scavenging assays. Boiling extracts of the seaweeds, except C. racemosa, were found to have higher total phenolic contents (TPC) than those obtained from the autoclave method. The antioxidant results also showed that O₂^•− scavenging activity existed only in the boiling extracts of C. racemosa, G. tenuistipitata, and U. lactuca. In DPPH and OH^• assays, however, almost all the boiling extracts were less active than the autoclave ones. Among the four alga species, Sargassum sp. was the most active. Both extracts of this seaweed had the highest TPC and also displayed the strongest DPPH^• and OH^• inhibitory activities. A strong positive-correlation between the antioxidant potency and TPC of the autoclave extracts was found, while for the boiling extracts such relation was very weak. This result thus reflected that in addition to the phenolic compounds, there might be some other active components present in these extracts involved in the antioxidant activity.     

Comparative assessment of antioxidant and cholinesterase inhibitory properties of the marigold extracts from Calendula arvensis L. and Calendula officinalis L.

Calendula sp. is an important medicinal and industrial plant with various bioactivities. In this study, we examined enzyme inhibitory effects of the n-hexane, dichloromethane, acetone, ethyl acetate, methanol, and water extracts of the leaf and flowers of Calendula arvensis L. and C. officinalis L. against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). The extracts were screened for their antioxidant activity using 2,2-diphenyl-1-picrylhydrazyl (DPPH), ferric ion-chelating capacity and ferric-reducing antioxidant power (FRAP) assays at 250, 500, and 1000 μg mL⁻¹. Total phenol and flavonoid quantification of the extracts was achieved using Folin-Ciocalteau and AlCl₃ reagents, respectively. The ethyl acetate extract of C. arvensis flowers was the most active in AChE inhibition assay (31.24 ± 1.29%), while the n-hexane extract of C. officinalis leaves exerted the highest ferric ion-chelating capacity (74.27 ± 2.25%). Thin layer chromatographic analysis indicated presence of flavonoid and triterpene derivatives mainly in the extracts.     

Evaluation of Ultrasound,Microwave, Ultrasound–Microwave,Hydrothermal and High Pressure Assisted Extraction Technologies for the Recovery of Phytochemicals and Antioxidants from Brown Macroalgae

This study aims to explore novel extraction technologies (ultrasound-assisted extraction (UAE), microwave-assisted extraction (MAE), ultrasound–microwave-assisted extraction (UMAE), hydrothermal-assisted extraction (HAE) and high-pressure-assisted extraction (HPAE)) and extraction time post-treatment (0 and 24 h) for the recovery of phytochemicals and associated antioxidant properties from Fucus vesiculosus and Pelvetia canaliculata. When using fixed extraction conditions (solvent: 50% ethanol; extraction time: 10 min; algae/solvent ratio: 1/10) for all the novel technologies, UAE generated extracts with the highest phytochemical contents from both macroalgae. The highest yields of compounds extracted from F. vesiculosus using UAE were: total phenolic content (445.0 ± 4.6 mg gallic acid equivalents/g), total phlorotannin content (362.9 ± 3.7 mg phloroglucinol equivalents/g), total flavonoid content (286.3 ± 7.8 mg quercetin equivalents/g) and total tannin content (189.1 ± 4.4 mg catechin equivalents/g). In the case of the antioxidant activities, the highest DPPH activities were achieved by UAE and UMAE from both macroalgae, while no clear pattern was recorded in the case of FRAP activities. The highest DPPH scavenging activities (112.5 ± 0.7 mg trolox equivalents/g) and FRAP activities (284.8 ± 2.2 mg trolox equivalents/g) were achieved from F. vesiculosus. Following the extraction treatment, an additional storage post-extraction (24 h) did not improve the yields of phytochemicals or antioxidant properties of the extracts.     

Antioxidant Capacity and Antimutagenic Activity of Natural Oleoresin from Greenhouse Grown Tomatoes (<Emphasis Type="Italic">Lycopersicon esculentum</Emphasis>)

Natural oleoresins rich in lycopene were obtained from two varieties of tomato (Zedona and Gironda) and their nutraceutical potential (antioxidant and antimutagenic capacity) was evaluated. Both oleoresins had a high content of lycopene, 58.33 ± 1.67 mg/g (Zedona) and 63.97 ± 0.80 mg/g (Gironda). The antioxidant activity (AA) of the oleoresins by β-carotene method were 56.4–74.5% (Zedona) and 51–72.8% (Gironda), while when using the free radical stable 2,2-diphenyl-picryl-hydrazyl (DPPH) method, the antiradical activity (ARA) was determined to be 18.2–32.7% (Zedona) and 16.6–26.7% (Gironda) for the concentrations tested that of 200–400 μM equivalents of lycopene. The antimutagenic activity of the oleoresins was tested against aflatoxin B₁ (AFB₁) using the microsuspension assay, both varieties had a very high antimutagenic potential against AFB₁ (60–66%).These results suggest the NCRT can be taken advantage to obtaining rich oleoresin in lycopene with a nutraceutical value.     

<Emphasis Type="Italic">In vitro</Emphasis> Antioxidant Activity of Aged Extracts of some Italian <Emphasis Type="Italic">Allium</Emphasis> Species

Antioxidant activity of fresh Allium sativum L. (garlic) is well known and is mainly due to unstable and irritating organosulphur compounds. Fresh garlic extracted over a prolonged period (up to 20 months) produces odourless aged garlic extract (AGE) containing stable and water soluble organosulphur compounds that prevent oxidative damage by scavenging free radicals. The aim of this study was to investigate the in vitro antioxidant activity of aged (up to 20 months) 15% hydroethanolic extracts of different parts (bulbs, bulblets, flower bulblets, flowers, and leaves) of three Allium spontaneous species which are endemic for Italian flora: Allium neapolitanum Cyr., Allium subhirsutum L., Allium roseum L. and to compare it with the in vitro antioxidant activity of aged 15% hydroethanolic extracts of bulbs and leaves of garlic. The antioxidant potential of aged extracts of all species has been evaluated using two different spectrophotometric assays: 2,2-diphenylpicrylhydrazyl (DPPH) test and the ferric reducing/antioxidant power (FRAP) assay. Furthermore the polyphenol content was determined. The aged extracts obtained from the leaves showed the best antioxidant activity, followed by flowers and then by bulbs in both used tests, while flower bulblets and bulblets exhibited lower results or no activity. The polyphenol content was generally directly correlated with antioxidant/antiradical activity. This study confirms the data obtained in previous researches, the wild-type species of Allium and in particular organs other than bulbs are more active and efficacious than garlic bulb. Surely leaves of these Allium spp. deserve special attention.     

Seasonal Variation of Phenolic Antioxidant-mediated α-glucosidase Inhibition of <Emphasis Type="Italic">Ascophyllum nodosum</Emphasis>

Ascophyllum nodosum is a brown seaweed that grows abundantly in the US Northeast coastal region. This study examined the seasonal variation of A. nodosum in phenolic contents and subsequent antioxidant, α-glucosidase and α-amylase inhibitory activities. A. nodosum was harvested monthly and extracted in hot water and the resulting extracts were spray-dried. The results indicate a clear seasonal variation in terms of phenolic content, with June and July being the highest (36.4 and 37 mg/g, respectively) and May the lowest (21.8 mg/g). The antioxidant activities, in terms of 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity, correlated with the phenolic contents observed (r = 0.81), with the month of July being the highest (58%) and April the lowest (26%). Similarly in terms of Trolox equivalent, July had the highest activity (15.53 μM) and April and May the lowest (8.40 and 8.27 μM, respectively). α-glucosidase inhibitory activity exhibited a pattern similar to the phenolic contents observed with July having the highest inhibitory activity (IC₇₀ 2.23 μg) and April the lowest (IC₇₀ 26.13 μg), resulting in an inverse correlation between IC₇₀ values and total phenolic content (r = −0.89). Such seasonal variation is believed to be caused by temperature-related stress considering that A. nodosum is a cold water species.     

Appraisal of Thai glutinous rice husk for health promotion products

Rice husks of the RD 6 variety were refluxed with water for 30, 60 and 120 min. The longest extraction time resulted in the greatest yield (0.089 ± 0.008%), radical scavenging activity (IC₅₀ = 37.203 ± 0.421 μg/ml), and total phenolic and flavonoid contents (7.512 ± 0.008 g GAE/100 g extract and 36.886 ± 0.004 g QE/100 g extract). Fatty acids of cosmetic importance, such as hexanoic, heptatonic, octanoic, nonanoic, stearic, palmitic, oleic and linoleic acids, were quantified using the best antioxidant extract (166.004 mg/kg). The total phenolic content was related to the antioxidant activity and total fatty acid content (r = 0.997 and 0.864) in linoleic acid (r = 0.989), which displayed antioxidant properties (r = 0.996). The extract was non-cytotoxic in vero cells. Furthermore, it was compatible and stable in cosmetic formulations. Therefore, rice husks should be further studied for use in health promotion products.     

Functional study of raw and cooked blue maize flour: Starch digestibility,total phenolic content and antioxidant activity

The purpose of this study was to determine the chemical composition and antioxidant capacity of blue maize (BM) (Zea mays L.) flour and to investigate the effects of polyphenol-containing extracts and BM wholegrain flour on starch digestion under uncooked and cooked conditions; commercial white maize flour was used as control. Total phenolic content in BM flour (BMF) (164 ± 14 mg gallic acid/g of dry matter) was higher than white maize (127 ± 7 mg gallic acid/g of dry matter), and the presence of anthocyanins (2.0 ± 0.5 mg cyanidin 3-glucoside/100 g) was detected. Also, an important scavenging activity against ABTS (2,2’-azino-di-(3-ethylbenzothiazoline)-6-sulfonic acid) and DPPH (2,2-diphenyl-1-picrylhydrazyl) radicals and ferric reducing power (FRAP) was determined. Extracts of BMF reduced amylase activity (>90% of inhibition). BMF showed higher slowly digestible and resistant starch contents, thus exhibiting lower predicted glycemic index than white maize. Total anthocyanins (r = −0.89 and r = −0.79, p<0.05), antioxidant capacity (r = −0.86 and r = −0.96, p<0.05), total starch (r = 0.99 and 0.92, p<0.05) and resistant starch content (r = −0.99 and r = −0.92, p<0.05) were correlated with pGI for uncooked and cooked flours, respectively. These results indicate the potential use of BMF and its phenolic-rich extract as functional ingredients to develop antioxidant and indigestible carbohydrate-rich foods with potential health benefits.     

Phenolics and Antioxidative Activities in Narrow-Leafed Lupins (Lupinus angustifolius L.)

Eight lupin (Lupinus angustifolius L.) genotypes grown at four locations in south central Alberta in 2004 were evaluated for variability in phenolic constituents and antioxidant activity measured by a photochemiluminescence assay. Genotype was the main source of variation for content of phenolic compounds and antioxidant activities. Phenolic compounds in genotypes varied minimally from 11.9 to 14.7 mg catechin equivalent and 4.15 to 4.95 mg rutin equivalent g⁻¹ lupin for total phenolic and flavonoid contents, respectively. Lupin genotypes exhibited weak antioxidant activity based on water–soluble substances (ACW) of 0.54 to 1.07 μmole Trolox equivalent antioxidant capacities (TEAC)/g with lag time ranging from 70 to 153 s and an antioxidant index of 6.7 to 14.5 and 1.9 to 3.3 μmole TEAC/g based on measurements of lipid-soluble substances (ACL). Antioxidant activity of lupin genotypes was not related to phenolic contents of seeds.     

Assessment of dermal wound healing and in vitro antioxidant properties of Avena sativa L.

Avena sativa L. (Poaceae) has been reported to have traditional utilization against skin diseases and inflammation. Therefore, in this study, the n-hexane, ethyl acetate, ethanol, and water extracts of A. sativa were investigated for their wound healing and antioxidant activities. Total phenol and flavonoid contents of the extracts were established spectrophotometrically. For the wound healing activity, linear incision and circular excision models on rats and mice were evaluated with a standard ointment Madecassol^®. Antioxidant activity was evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, ferrous ion-chelating, and ferric-reducing antioxidant power (FRAP) assays. Significant wound healing activity was observed with the ointment formulation of the ethanol extract at 1% concentration. The histopathological examination results also supported the outcome of both linear incision and circular excision wound models. All of the extracts exerted low antioxidant activity in the applied assays. The present study provides a scientific evidence for the traditional usage of A. sativa in the management of wound healing.     

Comparative Analysis of Native <Emphasis Type="Italic">Crocus</Emphasis> Taxa as a Great Source of Flavonoids with High Antioxidant Activity

Native Crocus taxa are abundant in regions with moderate and dry climate; however, their potential in the food industry has thus far been neglected. The objective of this study was to compare the quantitative and qualitative flavonoid content and antioxidant and cytotoxic activity in organs of several populations of Croatian native taxa and assess their potential for application in the food industry. The dominant flavonoids in the native Crocus taxa were kaempferol and quercetin. Tepals contained similar or higher concentrations of flavonoid-glycosides than other organs. Tepals from Cvv1 and Cvv2 populations contained more flavonoid-glycosides than the commonly used spice saffron (C. sativus stigmas). The FRAP antioxidant activity of Cvv1 and Cvv5 tepals was similar to that of standard Trolox. DPPH inhibition of Cvv1 and Cvv3 tepals was within the range of that recorded for saffron. Cvv1 tepals significantly reduced reactive oxygen species in the broadest concentration range (50–1000 μg/ml), and showed considerable antioxidant activity in the ABTS assay, equal to 82% of standard Trolox antioxidant activity. A significantly higher concentration of kaempferol-rutinoside was recorded in this than in other taxa. The flavonoid showed a very strong or strong correlation with antioxidant assays results, and a negative correlation with cellular reactive oxygen species concentration. We therefore presumed that kaempferol-rutinoside is one of the main antioxidant phenolics in Crocus tepals. None of the tested extracts showed cytotoxicity toward Caco-2 cells. The results revealed that Cvv tepals have potential as a food supplement and are a promising material for further food safety tests.     

Valorization of three varieties of grape

In the present investigation, seed methanolic extracts of three Vitis vinifera (Muscat d’Italie, Syrah and Carignan) were assayed for their antioxidant activities. Results showed that there are strong variations in the contents of total phenols (440.97–121.94 mg GAE g⁻¹ DW), flavonoids (48.07–16.81 mg EC g⁻¹ DW) and tanins (37.15–14.9 mg EC g⁻¹ DW) from the studied seeds. The phenolic composition of these extracts was determined by RP–HPLC after acid hydrolysis. The main phenolic compound was quercetin with 27.2% in Muscat d’Italie, 48.8% in Syrah and 28.4% in Carignan. Besides, all seed extracts showed remarkable DPPH radical scavenging activity with IC₅₀ values ranged from 1.8 to 30 μg ml⁻¹. EC₅₀ values of reducing power activity ranged from 100 to 120 μg ml⁻¹. The high phenolic content and the considerable antioxidant activities of vitis seed extracts could potentially be considered as an expensive source of natural antioxidants.