Antioxidant activity of microwave-assisted extract of Buddleia officinalis and its major active component

Buddleia officinalis Maxim, commonly used as rice dye for festivals, was extracted with ethanol using microwave-assisted extraction and Soxhlet extraction. The antioxidant activities of microwave-assisted extract of B. officialis (MEB) and Soxhlet extract of B. officianils (SEB) at the optimum extraction conditions were evaluated and compared with synthetic antioxidant butylated hydroxytoluene (BHT) employing DPPH free radical assay, ABTS assay, total antioxidant activity and reducing power. MEB and SEB had stronger antioxidant activities than BHT in all assays except reducing power, and the effects decreased as follows: MEB > SEB > BHT. The total phenolic contents of MEB and SEB reached 113.56 mg/g and 100.94 mg/g dry weight of extract, respectively, expressed as pyrocatechol equivalents, while the total flavonoids contents were 75.33 mg/g and 62.56 mg/g dry weight of extract, respectively, expressed as catechin equivalents (P < 0.05). Higher phenolic and flavonoids compounds may be major contributors to their higher antioxidant activities. Following activity-oriented separation, luteolin was isolated as an active principle, which exhibited excellent free radical scavenging activities with DPPH IC₅₀ 3.09 μg/ml and ABTS IC₅₀ 2.20 μg/ml.     

Enhancement of antioxidant activity,total phenolic and flavonoid content of black soybeans by solid state fermentation with Bacillus subtilis BCRC 14715

In the present study, a solid state fermentation of black soybeans with Bacillus subtilis BCRC 14715 was performed. The effect of fermentation on the changes of total phenolic and flavonoid content and antioxidant activities including 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging effect, and Fe²⁺-chelating ability exerted by various solvent (water, 80% methanol, 80% ethanol, 80% acetone) extracts of black soybeans was examined. It was found that fermentation enhanced the total phenolic and flavonoid content as well as antioxidant activity of the black soybean extract. Among the various extracts examined, the acetone extract of fermented black soybeans showed the highest total phenolic and flavonoid content. The acetone extract and the methanol extract of fermented black soybeans showed the highest DPPH free radical-scavenging effect and Fe²⁺-chelating ability, respectively. Analysis of extraction yields showed that the active principle associated with the DPPH radical-scavenging effect was most efficiently extracted from black soybeans using water, regardless of fermentation. Water and methanol effectively extract the Fe²⁺-chelating principles from non-fermented and fermented black soybeans, respectively.     

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.     

黑蒜提取物的抗氧化性与抗炎活性比较研究

目的对分离纯化黑蒜多糖的过程中得到6种黑蒜提取物,进行成分分析,并比较研究它们的抗氧化活性和抗炎活性。方法黑蒜经热水提取获得黑蒜水提物(hot water extract,HWE),经乙醇分离得到乙醇上清(ethanol supernatant extract,ESE)和沉淀(ethanol precipitate extract,EPE)提取物,并再经脱蛋白和乙醇分离得到脱蛋白的乙醇上清(deproteinized ethanol supernatant extract,d ESE)和沉淀(deproteinized ethanol precipitate extract,d EPE)提取物,再经DEAE 52纤维素层析纯化得到多糖提取物(purified polysaccharide extract,PPE)。首先采用薄层层析法分析了6种黑蒜提取物的单糖组成,还测定了总糖含量、还原糖含量、硫含量。再比较分析了6种多糖提取物的抗氧化与抗炎活性。结果 6种黑蒜提取物对DPPH自由基和ABTS自由基均具有良好的清除作用。6种黑蒜提取物对脂多糖(lipopoly saccharides,LPS)(20?g/mL)所致的RAW264.7细胞生长抑制均有显著性保护作用(P0.05)。6种黑蒜提取物对LPS(1?g/mL)诱导RAW264.7细胞NO,IL-1?,IL-6和TNF-?等细胞炎性因子的释放均有显著的抑制作用(P0.05)。结论黑蒜多糖提取物具有良好的抗氧化作用和抗炎活性,研究结果为黑蒜的进一步研发提供了理论依据和实际参考价值。     

Enzyme-enhanced extraction of antioxidant ingredients from red algae Palmaria palmata

The effect of various protease and carbohydrase treatments on the extraction of polyphenols and other antioxidant ingredients from the red algae Palmaria palmata (dulse) was investigated. In addition, the relative contribution of different fractions to the overall antioxidant capacity of the hydrolysate was evaluated. Considerable differences were observed both in total phenolic content (TPC) and antioxidant activities of the hydrolysates evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, oxygen radical absorbance capacity (ORAC) and ferrous ion-chelating ability assays. All the proteases tested had significant enhancing effect on the extraction of polyphenols and other active components compared to carbohydrases and cold water extraction (control). The Umamizyme extract had the highest TPC and consequently exhibited the strongest scavenging capacity against DPPH and peroxyl radicals. Further fractionation of the Umamizyme extract revealed that the crude polyphenol fraction possessed the highest peroxyl radical scavenging activity, whereas the crude polysaccharide fraction was more effective for chelating ferrous ions. The data from this study suggest the potential of protease treatment to improve value-added utilization of dulse extracts as antioxidants in functional foods and nutraceuticals.     

Antioxidant activities of extract and fractions from Tuber indicum Cooke & Massee

The antioxidant activities of ethanolic crude extract (ECE) and its four different solvent sub-fractions (namely, petroleum ether fraction (PEF), ethyl acetate fraction (EAF), n-butyl alcohol fraction (BAF) and the rest fraction (RF)) from Tuber indicum were investigated using several in vitro antioxidant assays. ECE and four sub-fractions possessed different antioxidant and radical-scavenging activities in different assays. BAF showed the most potent radical-scavenging activity on DPPH radicals, superoxide anion radicals and reducing power, with EC₅₀ values of 1.38, 0.96, 16.0 mg/ml, respectively. EAF exhibited the highest hydroxyl radical-scavenging and ferrous ion chelating activities with EC₅₀ values of 3.31 and 0.70 mg/ml, respectively. The total phenolics (TP) and total flavonoids (TF) were also determined. BAF had the highest TP and TF contents, and the next was EAF. These results showed that the amounts of phenolics and flavonoids were in accordance with higher effectiveness in scavenging radicals and chelating ferrous ions.     

A comparison between bark extracts from Pinus pinaster and Pinus radiata: Antioxidant activity and procyanidin composition

The composition and antiradical activity of procyanidins from the bark of two kinds of pine, Pinus pinaster and Pinus radiata, were compared. Both the total bark extract and the fraction soluble in both water and ethyl acetate (OW) were evaluated, because of their promising results in previous experiments.     

Antioxidant and cytotoxic activities of various fractions of ethanol extract of Dianthus superbus

This study examined the antioxidant and cytotoxic activities of various fractions (prepared by using solvents of varying polarity) of ethanol extract of Dianthus superbus (DS). The antioxidant activities of various fractions were evaluated in terms of their free radical-scavenging activity. The total phenolics and reducing powers of the fractions were measured. The cytotoxic activities of the fractions on three human malignant cell lines were also investigated. Among all fractions, the ethyl acetate fraction (EE-DS), which had the highest phenolic content and the strongest reducing power, exhibited the strongest antioxidant and cytotoxic activities.     

Antioxidant activity of Rhizoma Smilacis Glabrae extracts and its key constituent-astilbin

Rhizoma Smilacis Glabrae is widely consumed by Chinese as functional food and in folk medicine for its medicinal properties. In this study, methanol and water extracts of Rhizoma Smilacis Glabrae were prepared. The water extract was further divided into polysaccharide and supernatant fractions. Constituents in different extracts were analysed by capillary electrophoresis, and levels of total phenolics were also determined using the Folin-Ciocalteu method. Astilbin, the main constituent in the herb, was isolated and purified. Different antioxidant tests were employed to evaluate the antioxidant activities of the extracts and the isolated astilbin, and the results were compared with two commonly used synthetic antioxidants-butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT). Methanol, water extract and supernatant fraction showed concentration dependent antioxidant activity while polysaccharide didn’t show any antioxidant activity. Purified astilbin showed the strongest antioxidant activity in comparison to any other extracts.     

Phytochemicals and antioxidant activity of different parts of bambangan (Mangifera pajang) and tarap (Artocarpus odoratissimus)

Mangifera pajang (family: Anacardiaceae; local name: bambangan) and Artocarpus odoratissimus (familiy: Moraceae; local name: tarap) are popular edible fruits in Sabah, Malaysia. The flesh, kernel and peel from M. pajang; seed and flesh from A. odoratissimus were analysed for total antioxidant activity, total polyphenol, total flavonoid and total anthocyanins contents. M. pajang kernel extract displayed the highest free radical scavenging and ferric reducing activities. Total phenolic content of the samples were in the range of 5.96–103.3 mg gallic acid equivalent/g. M. pajang kernel and M. pajang flesh contained the highest and lowest total flavonoid content with the values of 10.98 and 0.07 mg rutin equivalent/g, respectively. The antioxidant activities of extracts were significantly correlated with the total phenolic and flavonoid content (but not the anthocyanins content). The phytochemicals and antioxidant properties of M. pajang and A. odoratissimus, especially their by-products (kernel/seed), indicate that they may impart health benefits when consumed and should be regarded as a valuable source of antioxidant-rich nutraceuticals.     

Nutritional and nutraceutical comparison of Jamaican Psidium cattleianum (strawberry guava) and Psidium guajava (common guava) fruits

Psidium cattleianum (strawberry guava) is one of many underutilised edible fruits that grow wild in Jamaica, and could potentially be commercially exploited to yield health and economic benefits. In this study, the total phenolics, proximate contents, and antioxidant, anti-inflammatory, and antimicrobial activities of P. cattleianum and P. guajava (common guava), a well-known species, were compared. Strawberry guavas were found to be superior to common guavas in antioxidant and antimicrobial activities, total phenolics and vitamin C content. They also possessed relatively high fibre content (24.9%). The hexane and ethyl acetate extracts of strawberry guavas showed cyclooxygenase-2 enzyme inhibitory activities of 18.3% and 26.5%, respectively (250 μg/mL), indicating anti-inflammatory activity. The EtOAc and MeOH extracts of P. guajava showed 56.4% (COX-2) and 44.1% (COX-1) inhibitory activity, respectively. Additionally, nine compounds were isolated from strawberry guava fruits, some of which demonstrated anti-inflammatory activity. These results indicate that strawberry guavas are beneficial for health.     

Antioxidant and anti-inflammatory properties of Dichondra repens Forst. and its reference compounds

Dichondra repens (DR) is the main constituent in herbal beverages and consumed daily as a nutrition supplement for the liver in Taiwan. This study investigated the antioxidant and anti-inflammatory effects of D. repens ethanol extract (EDR) and its reference compounds ex vivo and in vivo. Fingerprint chromatograms (from HPLC) indicated that EDR contained vanillin, umbelliferone and scopoletin. EDR was evaluated for its antioxidant effects and LPS-induced NO production in RAW 264.7 cells. EDR decreased the LPS-induced NO production and expressions of iNOS and COX-2 in RAW 264.7 cells. In vivo anti-inflammatory activities of EDR were assessed in mouse paw oedema, induced by λ-carrageenan (Carr). We investigate the antioxidant mechanism of EDR via studies of the activities of catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GPx) in the liver and the levels of malondialdehyde (MDA) and nitrite oxide (NO) in the oedematous paw. Serum NO and TNF-α were also measured. EDR exerts anti-inflammatory effects by suppressing TNF-α, NO, and might be related to the decrement of the level of MDA in the oedema paw via increasing the activities of CAT, SOD and GPx in the liver. The results show that EDR might be a natural antioxidant and anti-inflammatory agent.     

Antioxidant and anti-inflammatory properties of taiwanese yam (Dioscorea japonica Thunb. var. pseudojaponica (Hayata) Yamam.) and its reference compounds

Dioscorea japonica Thunb. var. pseudojaponica (DP) is consumed as food and widely used in traditional Chinese medicine in Taiwan. The aims of this study are to investigate the antioxidant and anti-inflammatory effects of ethanol extract of DP (EDP) and its reference compounds. Fingerprint chromatogram from HPLC indicated that EDP contains gallic acid and vanillic acid. EDP was evaluated for its antioxidant effects and LPS-induced nitrite oxide (NO) production in RAW264.7 cells. EDP decreased the LPS-induced NO production and expressions of iNOS and COX-2 in RAW264.7 cells. In-vivo anti-inflammatory activities of EDP were assessed in mouse paw oedema induced by λ-carrageenan (Carr). We investigated the antioxidant mechanism of EDP via studies of the activities of catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx) and the levels of malondialdehyde (MDA) in the oedematous paw. The results showed that EDP might be a natural antioxidant and anti-inflammatory agent.     

Antioxidant capacity of four polyphenol-rich Amazonian plant extracts: A correlation study using chemical and biological in vitro assays

Many plants used in Amazonian folk medicine present a high antioxidant activity. In this study, the antioxidant activities of four largely used plants, namely Byrsonima crassifolia, Davilla kunthii, Davilla rugosa and Inga edulis, were evaluated, using methanolic extracts of their leaves, fruits and bark and several different in vitro tests, based either on the capacity to scavenge free radicals (ORAC, TRAP) or on the ability to protect biological structures (LDLs, erythrocytes). The total phenolics (TP), flavanoids (TFA) and flavonols (TFO) were also measured. Almost all extracts performed well in all assays of antioxidative capacity, with best activities found in leaves (compared to fruits and bark). Most antioxidative performance indicators (ORAC, TRAP, LDL protection) correlated well with the TP and TFA content of the extracts. Conversely, correlation was lower between TFO and these indicators, reflecting a lower involvement of these compounds in antioxidant processes. Erythrocyte protection against oxidant-triggered haemolysis showed no correlation with any of the phenolic content indicators, suggesting that most of these compounds have a low ability to protect lipid targets in the erythrocyte membrane. On the other hand, protection of erythrocytes against haemolysis correlated positively with LDL protection. The extract of I. edulis leaves contained average amounts of polyphenols but ranked first in the majority of the tests, indicating the occurrence of particularly efficient compounds with very important antioxidant properties, which could be used for medicinal and other applications.     

Antioxidant activity of stilbene glycoside from Polygonum multiflorum Thunb in vivo

Stilbene glycosides were isolated from the ethanol extract of the roots of Polygonum multiflorum Thunb. Two samples were obtained; a fraction separated by macroporous resin and pure crystals of 2,3,5,4′-tetrahydroxystilbene 2-O-β-glucopyranoside. The antioxidant activities of these two samples were evaluated using antioxidant tests of rats in vivo. The activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) of the serum and the organs (liver, heart and brain of rats) of d-galactose induced senile rats which were fed with stilbene glycoside, were increased; however, the content of 2-thiobarbituric acid-reactive substances (TBARS) was decreased. It is concluded that the stilbene glycoside from Polygonum multiflorum Thunb possesses high in vivo antioxidant activity.     

Comparative analyses of seeds of wild fruits of Rubus and Sambucus species from Southern Italy: Fatty acid composition of the oil,total phenolic content,antioxidant and anti-inflammatory properties of the methanolic extracts

Fruit seeds are byproducts from fruit processing. Characterisation of the bioactive compounds present in seeds and evaluation of their potential biological properties is therefore of particular importance in view of a possible valorisation of seeds as a source of health beneficial components. In this work, we have analysed the seeds of Sambucus and Rubus species in order to identify their bioactive components and to determine the antioxidant and anti-inflammatory activities of the extracts. We first analysed their oil content, in order to assess the fatty acid profile and tocopherol content. Moreover, the methanolic extracts of the seeds were analysed for their total phenolic contents and antioxidant capacities. Polyphenols were identified by HPLC–ESI–MS/MS analysis. Furthermore, extracts were evaluated for their inhibitory effects on the production of LPS-induced inflammatory mediators (NO, CCL-20) in RAW 264.7 cells.     

GC/MS analysis and in vitro antioxidant activity of essential oil and methanol extracts of Thymus caramanicus Jalas and its main constituent carvacrol

Chemical composition of the essential oil, antioxidant activity (DPPH and β-carotene/linoleic acid assays), and total phenolic content (Folin–Ciocalteu assay) of aerial parts of Thymus caramanicus were determined. The highest radical-scavenging activity (DPPH test) was shown by the polar subfraction of the methanol extract (IC₅₀ = 43.0 μg/ml) which was also higher than that of butylated hydroxytoluene (BHT, IC₅₀ = 19.7 μg/ml). However, it was the nonpolar subfraction of the methanol extract that showed the highest inhibition (84.4%), as assessed by the β-carotene/linoleic acid assay, which was only slightly lower than that shown by BHT (93.3%). The antioxidant activities of the essential oil main component (carvacrol) were also evaluated for comparison. Total phenolic content of the polar subfraction, as gallic acid equivalents, was 124.3 μg/mg. Essential oil extracted from the aerial parts by hydrodistillation was analysed by GC and GC/MS. Fifteen constituents, representing 99.3% of the oil, were identified, of which the major ones, carvacrol (85.9%), thymol (3.3%), p-cymene (3.2%), γ-terpinene (1.8%) and borneol (1.3%), accounted for 95.6% of the oil.     

Antioxidant phenolic compounds from Smilax sebeana Miq.

Methanol extract and sub-fractions of Smilax sebeana rhizomes and roots were analyzed to evaluate the compounds involved in antioxidant activity. In all separated fractions of the different polarity solvents, ethyl acetate fraction showed the highest antioxidant activity and total phenolic content. This fraction was subjected to the sephadex LH-20 column and preparative HPLC for purification. Six phenolic compounds, chlorogenic acid (1), 4-formylphenol (2), epicatechin (3), cinchonain IIa (4), Ia (5) and Ib (6) were isolated and identified by spectroscopic analyses and further evaluated their potential antioxidant activities by DPPH and superoxide radical scavenging assays. Compared with synthetic antioxidant Trolox, except 4-formylphenol, the other isolated five compounds exhibited excellent antioxidant activities. This is the first report on the chemical constituents of S. sebeana which potentially involved in antioxidant activity. The results suggest that the ethyl acetate extract of S. sebeana might be used as a readily accessible source of natural antioxidant.     

Star-anise (Illicium verum) and black caraway (Carum nigrum) as natural antioxidants

The various solvent fractions of star-anise (Illicium verum) and black caraway (Carum nigrum), along with their spice powders and volatile oils, were prepared and evaluated for antioxygenic activity, using different methods. Star-anise powder and its ethanol/water (80:20)-soluble fraction showed strong antioxygenic activity in refined sunflower oil while the petroleum ether fraction exhibited marginal antioxygenic activity and the water-soluble fraction was practically devoid of any activity in sunflower oil. The black caraway powder showed marginal antioxygenic activity while its ethanol/water fraction (80:20) showed strong antioxygenic activity and all other fractions showed slight pro-oxygenic activity in refined sunflower oil. Both the spice powders and their extracts were also evaluated for antioxidant activity by linoleic acid peroxidaton, β-carotene-linoleate and 1, 1-diphenyl-2-picryl hydrazyl (DPPH) methods. Both the star-anise and black caraway powders, as well as their ethanol/water extracts, exhibited strong antioxygenic activity. Volatile oils from both the spices exhibited antioxygenic activity and the activity did not seem to be concentration-dependent. Volatile oils from star-anise showed relatively higher antioxygenic activity than did those from black caraway. Gas chromatography–mass spectroscopy (GC–MS) studies on star-anise and black caraway volatile oils resulted in the identification of 25 and 22 compounds, respectively, representing 94–97% of the total content.     

Antioxidant activity and phenolic content of raw and blanched Amaranthus species

The study was aimed to determine the antioxidant activity (total antioxidant and free radical-scavenging activities) and total phenolic content of Amaranthus sp. The effects of different blanching times (10 and 15 min) on antioxidant activity and phenolic content were also studied. Four types of Amaranthus species locally known as spinach, namely ‘bayam putih’ (Amaranthus paniculatus) (BP), ‘bayam merah’ (Amaranthus gangeticus) (BM), ‘bayam itik’ (Amaranthus blitum) (BI) and ‘bayam panjang’ (Amaranthus viridis) (BPG), were selected. Total antioxidant activity of water-soluble components in raw spinach was in the order of BI ≈ BM ≈ BPG > BP, whereas free radical-scavenging activity was in the order of BI > BPG > BM > BP. The total phenolic contents of BM and BP were significantly higher (p < 0.05) than other samples. All the studied spinach species possessed different antioxidant activities and phenolic contents. Antioxidant activities and phenolic contents of all the spinach were in the order of raw > blanched 10 min > blanched 15 min. Blanching up to 15 min may affect losses of antioxidant activity and phenolic content, depending on the species of spinach.