Search

This study was designed to evaluate the antioxidant activity of phenolic compounds of for Lamiaceae: Salvia officinalis, Satureja calamintha, Mentha pulegium and Marubium vulgare using ferric reducing power (FRAP) and radical scavenging method (DPPH). Preliminary phytochemical analysis shows that the major constituents of crude extracts (Hydromethanolic, hydroacetonic) are tannins, saponins, quinones, flavonoids, terpenoids and reducing compounds in the four plants. In quantitative analysis, variable polyphenols, flavonoids and condensed tannins content are recorded. The highest polyphenols content is that of the aqueous/methanol crude extract of Salvia officinalis (188.92 ± 1.19 mg GAE/gE), followed by aqueous/acetone crude extract of Mentha pulegium (176.55 ± 2.49 mg GAE/gE). Flavonoids and condensed tannins content of crude extract showing a high content in aqueous/methanol extract of Mentha pulegium and Satureja calamintha (93.64 ± 0.26mg EQC/gE and 25.44 ± 0.71 mg EQC/gE), respectively. Scavenging activity of the free radical DPPH, revealed that the aqueous/methanol extract of Salvia officinalis shown a relatively high antioxidant activity (IC50 = 1.07 μg/ml) compared with ascorbic acid (IC50 = 0.91 μg/ml). FRAP method revealed that the extracts of Mentha pulegium showed the highest power to reduce iron (EC50 = 0.147 mg/ml), but lower than that of ascorbic acid (EC50 = 0.057 mg/mL). [ABSTRACT FROM AUTHOR]

In this study, the physicochemical and sensorial properties of set-type yogurt (STY)-enriched with water-soluble Melastoma dodecandrum Lour. fruit extract (MDLE) loaded nano-nutriosomes (MDLE-NU) or chitosan-coated nano-nutriosomes (CH-MDLE-NU) powder were investigated during 21 days of cold storage at 4 ± 2 °C. The results showed that MDLE powder has a high amount of phenolics, flavonoids, anthocyanins (59.42, 38.61, and 2.10 g/100g, respectively), and antioxidant activity ranging from 54.12 to 71.37 g/100g. MDLE successfully encapsulated in NU and CH-NU, where encapsulation efficacy reached 96.92% and particle size ranged from 144.57 to 172.30 nm with an acceptable range of PDI (<0.3). However, the commercial food custom of normal NU is still challenging, therefore, freeze-drying of MDLE-NU and CH-MDLE-NU can make their usage applicable. Our results showed that adding MDLE-NU and CH-MDLE-NU powder to STY significantly (p < 0.05) improved the color, water holding capacity, microstructure, texture, and sensory evaluation, as well as reduced whey syneresis, and losing fat globules of STY. Despite MDLE powder-enriched STY showing higher polyphenol content and antioxidant activity than MDLE-NU or CH-MDLE-NU, nutriosomes systems protect bioactive compounds of MDLE against unfavorable conditions in yogurt during cold storage. In which the reduction of total phenolics, total flavonoids, and total anthocyanins from STY-MDLE at the end of storage (21st day) was 2.7, 4.82, and 17.4%, while was 1.02, 2.6, and 3.03%, in STY–CH–MDLE-NU, respectively. This study indicates that MDLE is a promising ingredient to produce functional foods, besides, nutriosomes systems are a promising nanocarrier to encapsulate and protect the bioactive compounds. [Display omitted] • Water-soluble Melastoma dodecandrum extract (MDLE) is good source for polyphenols. • MDLE-loaded nano-nutriosomes (MDLE-NU) was successfully formed. • Chitosan (CH) coating was successfully given onto MDLE-NU to obtain CH-MDLE-NU. • CH-MDLE-NU had highest encapsulation efficacy with nano-sized range and PDI<0.3. • Yogurt properties was improved by adding freeze-dried CH-MDLE-NU powder. [ABSTRACT FROM AUTHOR]

Corrosive processes in acidic medium reduce the performance and durability of metallic materials, causing problems to several industries. Corrosion inhibitors are commonly used to decrease these effects. As these inhibitors must be ecologically friendly currently, this work evaluated the anticorrosive effect of natural extracts of coffee husks (Coffea arabica L.) in the protection of carbon steel in 1 mol L-1 HCl solution. Extractions were performed using water as the extraction solvent. The polyphenols content increased with the extraction temperature, and the extracts were produced using 100 ºC. Extract concentrations of 10, 20 and 30 % v/v were analyzed as inhibitors for carbon steel in acid medium, using weight loss and electrochemical tests, as well as scanning electron microscopy. There was an increase in the inhibition efficiency as the extract concentration increased, reaching values around 97 % using 30 %v/v of extract for the weight loss tests.

Folk medicine sometimes involves the use of salvia species for therapeutic purposes. Polyphenols with the highest amounts included rosmarinic acid (7.358mg/g), catechin (1.5 mg/g), vanillin (1.00 mg/g), chlorogenic acid (0.53 mg/g), quercetin (0.16 mg/g), and p-coumaric acid (0.015). Furthermore, the results showed that S. multicaulis has a high content of total phenol (4.39 mg/g) and DPPH activity (8.44 mg/g). Salvia multicaulis could be potentially used as a medicinal plant because of its antioxidant activity and polyphenol content. [ABSTRACT FROM AUTHOR]

In this study, leaves and flowers of Atractylis babelii were chosen to investigate their antioxidant activities. Thus, a comparison between the antioxidant properties of ethanolic crude extracts obtained by two extraction methods, maceration and soxhlet extraction, was performed using two different tests; DPPH and ABTS radical assays. Besides, total polyphenol, flavonoid and condensed tannin contents were determined in leaves and flowers of Atractylis babelii by colorimetric methods. The results showed that there was no correlation between phenolic contents of plant parts and their antioxidant activity. Whereas, leaves and flowers of Atractylis babelii showed that both had almost similar phenolic contents, while their antioxidant activity depended on the plant parts. Furthermore, the antioxidant activity of plant parts was also depended on extraction method. Such a result may be likely ascribed to a variety of chemical composition can be found in Atractylis babelii extracts which has been related to its antioxidant properties.

Parsley ( Petroselinum hortense L.) plants cultivated under controlled conditions were exposed to different doses of cadmium to investigate the antioxidant capacity and cadmium accumulation in the samples. Two-months-old parsley seedlings were treated with four different concentrations of CdCl (0, 75, 150, and 300 μM) for fifteen days. Cadmium level in leaves increased significantly by increasing the Cd contamination in the soil. Total chlorophyll and carotenoid content declined considerably with Cd concentration. Cd treatment caused a significant increase lipid peroxidation in tissue of leaf. Superoxide dismutase activity (SOD, EC 1.15.1.1) increased partially at 75 and 150 μM CdCl concentrations whereas the activity decreased at 300 μM CdCl. Catalase (CAT, EC 1.11.1.6) and ascorbate peroxidase (APX, EC 1.11.1.11) activities were reduced by Cd application. Total phenolic compound amount increased significantly with increasing Cd concentration, as ferric reduction power, superoxide anion radical, and DPPH˙ free radical scavenging activities elevated slightly by the concentration. These results suggest that antioxidant enzymes activities were repressed depending on accumulation of cadmium in leaves of parsley while the non-enzymatic antioxidant activities slightly increased. [ABSTRACT FROM AUTHOR]

In this study, 50% ethanol extract prepared front dry leaves of eight plants grown wildly in Mongolia were characterized for DPPH radical scavenging activity, ABTS radical cation scavenging activity, superoxide anion scavenging activity, ferric reducing power, iron chelating ability, and content of total phenol, flavonoid, and flavanol in order to find good sources of natural antioxidant from plant kingdom. Correlation coefficients between antioxidant parameters and contents of polyphenoiic compounds were also calculated. Among them, leaves of Vaccinium vitis-idaeae, Paeonia anomala, Rosa acicularis, and Hippophae rhamnoides were rich in poiyphenoiics and exerted strong scavenging activity against DPPH radical, ABTS radical cation, and superoxide anion and reducing power. [ABSTRACT FROM AUTHOR]

Mentha pulegium L. is a medicinal and aromatic plant belonging to the Labiatae family present in the humid to the arid bioclimatic regions of Tunisia. We studied the effect of different salt concentrations on plant growth, mineral composition and antioxidant responses. Physiological and biochemical parameters were assessed in the plant organs after 2 weeks of salt treatment with 25, 50, 75 and 100 mM NaCl. Results showed that, growth was reduced even by 25 mM, and salt effect was more pronounced in shoots (leaves and stems) than in roots. This growth decrease was accompanied by a restriction in tissue hydration and K+ uptake, as well as an increase in Na+ levels in all organs. Considering the response of antioxidant enzymes to salt, leaves and roots reacted differently to saline conditions. Leaf and root guaiacol peroxidase activity showed an increase by different concentration of NaCl, but superoxide dismutase activity in the same organs showed a slight modification in NaCl-treated leaves and roots. Moreover, polyphenol contents and antioxidant activity were analysed in M. pulegium leaves and roots under salt constraint. The analysis showed an increase of total polyphenol content (2.41–8.17 mg gallic acid equivalent g−1 dry weight) in leaves. However, methanol extract of leaves at 100 mM NaCl displayed the highest DPPH· scavenging ability with the lowest IC50 value (0.27 μg ml−1) in comparison with control which exhibited IC50 equal to 0.79 μg ml−1. [ABSTRACT FROM AUTHOR]