Evaluation of antioxidant,antibacterial and anti-tyrosinase activities of four Macaranga species

The methanolic fresh leaf extracts of Macaranga gigantea, Macaranga pruinosa, Macaranga tanarius and Macaranga triloba were screened for their antioxidant properties (AOP), tyrosinase inhibition and antibacterial activities. Total phenolic content (TPC), 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging, ferric-ion reducing power (FRAP), ferrous-ion chelating (FIC) and lipid peroxidation inhibition (LPI) activities were used to evaluate the AOP. Modified 3,4-dihydroxy-L-phenylalanine (L-DOPA) method was used to determine tyrosinase inhibition activity, whereas antibacterial activity was determined using the disc-diffusion technique. TPC screening of the same species from different collection sites showed no significant difference between sites. M.triloba showed the highest ascorbic acid equivalent antioxidant activity (AEAC), FRAP and LPI values. M. tanarius, which showed the lowest TPC, AEAC, FRAP and LPI activities, exhibited the best FIC activity. M. pruinosa showed the best tyrosinase inhibition activity, whereas M. triloba showed the best antibacterial activity against Gram-positive bacteria species, with minimal inhibition dosage (MID) values as low as 10 μg/disc.     

Polyphenols and triterpenes from Chaenomeles fruits: Chemical analysis and antioxidant activities assessment

Mugua, fruit of the genus Chaenomeles, is a valuable source of health food and Chinese medicine. To elucidate the bioactive compounds of five wild Chaenomeles species, extracts from fresh fruits were investigated by HPLC-DAD/ESI-MS/MS. Among the 24 polyphenol compounds obtained, 20 were flavan-3-ols (including catechin, epicatechin and procyanidin oligomers). The mean polymerisation degree (mDP) of procyanidins was examined by two acid-catalysed cleavage reactions; the mDP value was the highest in Chaenomeles sinensis and the lowest in Chaenomeles japonica. Total polyphenol content (TPC) reached 46.92 and 46.28 mg/g gallic acid equivalents (GAE) in Chaenomeles speciosa and Chaenomeles thibetica, respectively, although their main bioactive compounds were different (being epicatechin and procyanidin B2 in the former, and catechin and procyanidin B1 in the latter). These two species also exhibited equally strong free radical scavenging activities. Our results further showed that the antioxidant ability of Chaenomeles fruits was significantly correlated to their total polyphenol contents. Two triterpenes (oleanolic acid and ursolic acid) were the highest quantity in Chaenomeles cathayensis and C. thibetica, respectively.     

Structural characterisation of polysaccharides from Tricholoma matsutake and their antioxidant and antitumour activities

In this study, polysaccharides from Tricholoma matsutake (TM-P) were purified using a DEAE-Sepharose fast flow column and three polysaccharide fractions (TM-P1, TM-P2 and TM-P3) were obtained. The chemical composition and structural characteristics of TM-P2 were quite different from those of TM-P1 and TM-P3. TM-P2 consisted of glucose, galactose and mannose with a molar ratio of 5.9:1.1:1.0. The glycosidic linkages were mainly composed of 1,6- and 1-linked glucose. Furthermore, TM-P2 showed the strongest in vitro antioxidant and antitumour activities. The oxygen radical absorbance capacity (ORAC) of TM-P2 was 2100.44 μmol Trolox/g. The antiproliferative activities of TM-P2 (4.0 mg/ml) on the growth of HepG2 and A549 cells were 67.98% and 59.04%, respectively.     

Effects of gamma irradiation on fourth-instar Plodia interpunctella (Hübner) (Lepidoptera: Pyralidae)

Effects of gamma irradiation on fourth-instar Plodia interpunctella (Hübner) (Lepidoptera: Pyralidae) larvae in infested dates (Boufeggous variety) were assessed. Larvae were exposed to different gamma irradiation doses ranging from 300 to 900 Gy. Feeding, pupation, adult emergence and survival were very sensitive to ionizing irradiation. When irradiated at a dose of 300 Gy and higher, food consumption and weight gain were significantly affected, in a dose-dependent manner. Twenty days after irradiation, the weight loss at doses of 300, 450 and 600 Gy was 42%, 47% and 49%, respectively. At doses of 750 and 900 Gy, the weight of larvae diminished by 51% and 54%, respectively. In contrast, the controls gained 20% in weight. Development of larvae to the pupal stage was not prevented completely but none of the pupae emerged as adults. At 300 Gy, 21% of larvae survived 44 d after irradiation and successfully pupated. An absorbed dose of 450, 600, 750 or 900 Gy applied to larvae caused 100% mortality by 44, 38, 38 and 22 d post-treatment, respectively. The minimum dose required to prevent damage from feeding and adult emergence was 300 Gy while doses required to cause death were ?450 Gy.     

Essential oil composition,antimicrobial and antioxidant activities of Satureja cuneifolia Ten.

Satureja cuneifolia Ten. is a well-known aromatic plant which is frequently used as a spice and herbal tea in Anatolia. S. cuneifolia oil was analyzed by gas chromatography/mass spectrometry (GC/MS). The major components of S. cuneifolia oil were carvacrol (44.99%) and p-cymene (21.61%). The essential oil of S. cuneifolia exhibited antimicrobial activity against all of the tested foodborne and spoilage bacteria. The minimum inhibitory concentration (MIC) values for test bacteria which were sensitive to the essential oil of S. cuneifolia were in the range of 600–1400 μg/ml. Antioxidant activities of the essential oil and the methanolic extract from S. cuneifolia were evaluated by using DPPH radical scavenging, β-carotene–linoleic acid bleaching and metal chelating activity assays. In addition, the amounts of total phenol components in the plant methanolic extract (222.5 ± 0.5 μg/mg) and the oil (185.5 ± 0.5 μg/mg) were determined.     

Codium tomentosum and Plocamium cartilagineum: Chemistry and antioxidant potential

The chemical composition of green Codium tomentosum Stackhouse and red Plocamium cartilagineum (Linnaeus) P.S. Dixon seaweeds from the Atlantic Ocean surrounding Portugal was studied. For the first time, the profile of organic acids was analysed in these matrices: seven and four organic acids were detected in green and red species, respectively. In P. cartilagineum these compounds were present in vestigial amounts, whilst C. tomentosum exhibited a higher content, with oxalic acid being the main compound. Phenolics, UV-absorbing compounds, were absent in both species. Volatiles profile was also determined for the first time and a total of 41 compounds were identified, which included alcohols, aldehydes, esters, halogenated compounds, ketones, monoterpenes (namely terrestrial ones), norisoprenoid derivatives, amongst others. Norisoprenoid derivatives and aldehydes were predominant. The main volatiles in green and red seaweeds were limonene and benzophenone, respectively. Additionally, both species revealed considerable antioxidant activity against both reactive oxygen (superoxide radical) and reactive nitrogen (nitric oxide) species, in a concentration-dependent manner.     

In vitro antioxidant activities of methanol extracts of five Phyllanthus species from India

In this study, the antioxidant activity of methanol extracts of five plants from the genus Phyllanthus was evaluated by various antioxidant assays, including total antioxidant, free radical scavenging, superoxide anion radical scavenging, hydrogen peroxide scavenging, nitric oxide scavenging, reducing power and metal ion chelating activities. The various antioxidant activities were compared to standard antioxidants such as butylated hydroxytoluene and ascorbic acid. All the extracts showed strong antioxidant activity in all the tested methods. Among the five plants Phyllanthus debilis has been found to possess the highest activity in all tested models, the activity decreased in the order Phyllanthus debilis>Phyllanthus urinaria>Phyllanthus virgatus>Phyllanthus maderaspatensis>Phyllanthus amarus. In addition to the antioxidant activity of these plants, the total phenolic compounds, flavonoids and flavonols were measured in the extracts. A correlation between the antioxidant activity and total phenolic content was observed.     

Enhanced antioxidant activity of Monascuspilosus fermented products by addition of ginger to the medium

The fermented products of Monascus sp. are known for their antihypercholesterolaemic effects, however, their antioxidant activities are different from those of many plant-derived foods. To evaluate the effect of ginger addition into the medium on the antioxidant activity of Monascuspilosus fermented products, we cultured uninoculated PDB medium (PDB), inoculated PDB medium (MP), uninoculated ginger-containing medium (PDBG), and inoculated ginger-containing medium (MPG). The broth and mycelia were collected, freeze-dried, and extracted to evaluate their free radical scavenging activities, inhibition of peroxidation, phenolic content, inhibition of DNA damage, cellular antioxidant activity, and expression of the antioxidant enzymes. The results showed that MPG had significantly higher antioxidant activity than PDB, MP, and PDBG at all fermentation time points. Moreover, the fermentation process significantly increased the antioxidant activities of MPG. After the inherent level of antioxidant capacity was increased, the modified M. pilosus fermented product demonstrated a higher anti-atherosclerotic value than the unmodified product.     

Determination of antioxidant activities of various extracts and essential oil compositions of Thymus praecox subsp. skorpilii var. skorpilii

The aim of this work is to examine the chemical composition and antioxidant activity of separated essential oils and different solvent extracts of Thymus praecox subsp. skorpilii var. skorpilii (TPS). The ethanol, acetone, methanol, hexane, aqueous extracts and separated essential oils of TPS were assessed for their antioxidant activities. Antioxidant activities were evaluated by reduction of Mo(VI) to Mo(V), reducing power, superoxide scavenging activity, free radical-scavenging activity, metal chelating activity, linoleic acid peroxidation, hydrogen peroxide scavenging activity and peroxide scavenging activity. Essential oils were characterized in total to be 41 components, whereas 9 components were isolated by column chromatography for antioxidant activity. TPS essential oil was found to contain thymol (40.31%) and o-cymene (13.66%) as the major components. The ethanol, methanol and water extracts exerted significant free radical-scavenging activity. The methanol and water extracts displayed highest superoxide scavenging activity. The water extract has the highest total phenolics (6.211 mg gallic acid (GAE)/g DW) and flavonoids (0.809 mg quercetin/g DW).     

Quantification of the polyphenolic fraction and in vitro antioxidant and in vivo anti-hyperlipemic activities of Hibiscus sabdariffa aqueous extract

In the present study the quantification of the polyphenolic fraction, anthocyanins and other polar compounds, the antioxidant capacity and the anti-hyperlipemic action of the aqueous extract of Hibiscus sabdariffa has been achieved. Seventeen compounds were successfully quantified either by HPLC-DAD or HPLC-ESI-TOF-MS. Six of them were directly quantified by their corresponding standards, whereas the rest were indirectly quantified as equivalents using standards of similar compounds. The antioxidant capacity have also been estimated by comparing different assays, i,e, Trolox equivalent antioxidant capacity (TEAC), ferric reducing antioxidant power (FRAP), oxygen radical absorbance capacity (ORAC), and measurement of thiobarbituric acid reacting substances (TBARS). H. sabdariffa showed high reducing capacity in FRAP assay and significant capability to scavenge peroxyl radicals in the ORAC assay. Nevertheless, the extract exhibited poor efficacy to inhibit peroxyl radicals in lipid systems. The plant extract also exhibited the capacity to decrease serum triglyceride concentration on hyperlipemic mouse model.     

Effects of gamma irradiation on the development and reproduction of Plodia interpunctella (Hübner) (Lepidoptera: Pyralidae)

The inhibitory effects of gamma irradiation were demonstrated on the development and reproduction including egg hatch, pupation, adult eclosion and oviposition of Plodia interpunctella. Failure of all these events increased with increasing doses from 0.1 to 1.0 kGy. However, the rates of developmental inhibition were different among three behavioral events. Egg hatch was almost completely inhibited by 0.5 kGy and higher doses. Pupation was completely inhibited by 0.25 kGy, but adult eclosion was not completely inhibited even by 1.0 kGy. In addition, different age groups within the egg and final larval stages differed in their susceptibility to 0.1 and 0.25 kGy doses; the rates of both hatching and pupation were lower when young individuals were irradiated. Fecundity and hatchability of eggs were greatly reduced when pupae were irradiated at 0.1 kGy and completely inhibited at 0.25 kGy and higher doses. This suggests that although some adults eclosed from pupae irradiated at 0.25 kGy and higher doses, they were not able to lay eggs. Our results suggest that irradiation at 0.5 kGy is appropriate for the inhibition of development and reproduction of P. interpunctella.     

Phenolics from hull of Garcinia mangostana fruit and their antioxidant activities

The air-dried fruit hulls of Garcinia mangostana Linn. were extracted with 70% MeOH, and then partitioned into the n-BuOH fractions. Furthermore, three major phenolic components related to their antioxidant activities were purified by silica gel column chromatography and Sephadex LH-20 and then identified as P₁ (1,3,6,7-tetrahydroxy-2,8-(3-methyl-2-butenyl)), P₂ [1,3,6-trihydroxy-7-methoxy-2,8-(3-methyl-2-butenyl) xanthone] and P₃ (epicatechin) using UV–visible spectrophotometry, IR spectrophotometry and NMR spectroscopy, respectively. The antioxidant activities of three major phenolics were evaluated using different tests, including the free radical scavenging capability and total antioxidant activity in a linoleic acid peroxidation. These three phenolic compounds exhibited different antioxidant activities in these antioxidant tests. The hydroxyl radical and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging capabilities and the activity against linoleic acid peroxidation of P₁ were greater than those of P₂ and P₃, while the superoxide anion radical scavenging activity of P₃ was greater than that of P₁, but was close to that of P₂ or α-tocopherol. An activity-guided isolation and purification process was used to identify the components showing the strong DPPH radical scavenging activity from G. mangostana Linn.     

Evaluation of antioxidant activities of various solvent extracts of Carissa opaca fruits

The chloroform and aqueous fractions of Carissa opaca fruit, a traditional medicinal fruit in Pakistan possessed a high amount of total phenolic and flavonoid contents as compare to other solvent fractions with potent antioxidant activities in scavenging DPPH, superoxides, hydroxyl, hydrogen peroxide, ABTS radicals, and had strong iron chelating activity. On the other hand, the ethyl acetate fraction showed the highest inhibition of β-carotene linoleic acid peroxidation and phosphomolybdate assay. A high correlation coefficient existed between EC₅₀ values of DPPH, superoxides, hydroxyl, hydrogen peroxide, ABTS radicals, total phenolics and flavonoids, but a non significant correlation was found in the case of iron chelaters, β-carotene and phosphomolybdate assay. This study verified that the chloroform and aqueous fractions have strong antioxidant activities which were correlated with its high level of phenolics and flavonoids. These fractions can be used as a source of potential antioxidant or functional food material.     

Antioxidant activities of Salvia miltiorrhiza and Panax notoginseng

Traditional Chinese medicinal herb Salvia miltiorrhiza (SM) and Panax notoginseng (PN) have been widely used for the prevention and treatment of vascular diseases in the clinics. To better understand their mechanisms of pharmacological actions, the in vitro antioxidant activities of extract of Salvia miltiorrhiza (ESM) and extract of Panax notoginseng (EPN) were evaluated with different antioxidant testing systems. Their activities of scavenging superoxide anion radicals, DPPH radicals, hydroxyl radicals, and hydrogen peroxide, chelating Ferrous ion, and ferric ion reducing power were assessed. The results showed that the mechanisms of their antioxidant effects were distinct and diverse. ESM possessed strong reducing power and high scavenging activities against free radicals including superoxide anion, hydroxyl and DPPH radicals, but a weaker scavenging activity for hydrogen peroxide. ferrous ion chelating activity of ESM was undetectable at the tested concentrations. In contrary, EPN exhibited strong ferrous ion chelating activity and high scavenging activities against hydrogen peroxide, hydroxyl radicals, and a weak activity against superoxide anion and DPPH free radicals. EPN did not show any ferric ion reducing power. Since their antioxidant mechanisms are complementary, the combined use of ESM and EPN might be even more beneficial. These antioxidant properties of SM and PN are likely part of the reasons that they are effective in the prevention and treatment of vascular diseases.     

In vitro antioxidant and antimicrobial activities of the extract of Pericarpium Citri Reticulatae of a new Citrus cultivar and its main flavonoids

To provide the base for the application of a new cultivar of Citrus reticulata Blanco, whose family is Rutaceae, a flavonoid extract of Pericarpium Citri Reticulatae (FEPCR), the dried rind of the ripe citrus, was obtained with 80% aq. ethanol. Total flavonoid content of FEPCR was determined by a colorimetric method. Total phenol content was estimated as gallic acid equivalents. The major constituents of FEPCR, including Hesperidin, Nobiletin and Tangeretin, were determined by HPLC analysis. The antioxidant activities of FEPCR, Hesperidin, Nobiletin and Tangeretin were evaluated by various antioxidant assays, including DPPH scavenging, hydroxyl radical scavenging, superoxide anion radical scavenging, hydrogen peroxide scavenging and reducing power. All samples showed antioxidant activities to some degree in all the tested methods. In addition to the antioxidant activity, the antimicrobial assay was measured as well. Six strains of microorganisms including Escherichia coli, Staphylococcus aureus, Staphylococcus epidermidis, Enterococcus faecalis, Salmonella typhi and Enterobacter cloacae were used in the tests. FEPCR and Hesperidin displayed a broad antimicrobial spectrum and exerted antimicrobial effects in antimicrobial tests. But Tangeretin and Nobiletin exhibited low antimicrobial activities.     

Anthraquinone profiles, antioxidant and antimicrobial properties of Frangula rupestris (Scop.) Schur and Frangula alnus Mill. bark

Frangula rupestris and Frangula alnus are deciduous shrubs distributed in Balkan Peninsula. While the bark of F. alnus is medicinally widely used, little is known about chemical and biological properties of F. rupestris. In the present study, F. rupestris and F. alnus bark were evaluated for their reducing power, DPPH radical scavenging and chelating activity, as well as antioxidant activity in β-carotene-linoleic acid assay. In addition, phenolic content, anthraquinone profile and antimicrobial activity of F. rupestris and F. alnus bark were determined. The most represented anthraquinone derivatives in F. rupestris and F. alnus bark were physcion (0.11 mg/g) and emodin (2.03 mg/g), respectively. Both species demonstrated excellent antioxidant and antimicrobial activities with MIC values equal or lower than 2.5 mg/mL. The presented research indicates that both species may have health benefits as natural antioxidants and antimicrobial agents for use in functional foods or medicine.