A novel bioactive peptide derived from enzymatic hydrolysis of Ruditapes philippinarum: Purification and investigation of its free-radical quenching potential

We purified a novel antioxidant peptide from Ruditapes philippinarum (R. philippinarum) and investigated its free radical scavenging activities. To prepare the peptide, eight proteases were tested for enzymatic hydrolysis. α-chymotrypsin hydrolysate, which showed clearly superior hydroxyl radical scavenging activity (p < 0.05), were further purified using a flow filtration system and consecutive chromatographic methods. Finally, a novel antioxidant peptide was obtained, and the sequence was identified as Ser-Val-Glu-Ile-Gln-Ala-Leu-Cys-Asp-Met. The peptide from R. philippinarum effectively scavenged hydroxyl, DPPH, alkyl and superoxide radicals, with observed IC₅₀ values of 0.042, 0.091, 0.107 and 0.372 mg/ml, respectively. This is the first report of an antioxidant peptide derived from the hydrolysates of R. philippinarum which, further, possesses competitive free radical quenching potential.     

Antioxidant activity of extract from Polygonum cuspidatum

Numerous diseases are induced by free radicals via lipid peroxidation, protein peroxidation and DNA damage. It has been known that a variety of plant extracts have antioxidant activities to scavenge free radicals. Whether Polygonum cuspidatum Sieb. et Zuce has antioxidant activity is unknown. In this study, dried roots of Polygonum cuspidatum were extracted by ethanol and the extract was lyophilized. Free radical scavenging assays, superoxide radical scavenging assays, lipid peroxidation assays and hydroxyl radical-induced DNA strand scission assays were employed to study antioxidant activities. The results indicate that the IC50 value oí Polygonum cuspidatum extract is 110 microg/ml in free radical scavenging assays, 3.2 microg/ml in superoxide radical scavenging assays, and 8 microg/ml in lipid peroxidation assays, respectively. Furthermore, Polygonum cuspidatum extract has DNA protective effect in hydroxyl radical-induced DNA strand scission assays. The total phenolics and flavonoid content of extract is 641.1 +/- 42.6 mg/g and 62.3 +/- 6.0 mg/g. The results indicate that Polygonum cuspidatum extract clearly has antioxidant effects.     

Protection of human erythrocyte using Crinumasiaticum extract and lycorine from oxidative damage induced by 2-amidinopropane

The intention of this investigation was to evaluate the free radical scavenging activity and erythrocyte protective activity of ethanolic extract of Crinumasiaticum (L) and lycorine. The ethanolic extract of C. asiaticum (L) and lycorine were found to have different levels of antioxidant properties in the test models. Both ethanolic extract of C. asiaticum (L) (0.5–2.5 mg/ml) and lycorine (0.010 mg–0.050 mg/ml) increases the percentage of lipid peroxidation inhibition (26.25 ± 0.23% and 19.25 ± 0.23%) and enhances the free radical scavenging activity (20.92 ± 0.22% and 20.52 ± 0.22%), scavenging of hydrogen peroxide (25.67 ± 0.17% and 23.07 ± 0.3%) superoxide anion scavenging activity (27.69 ± 0.16% and 16.09 ± 0.7%) at concentration of 2.5 and 0.050 mg of C. asiaticum (L) and lycorine, respectively. But compared with tocopherol (P < 0.05) less activity was observed by C. asiaticum (L) and lycorine. The ethanolic extract of C. asiaticum (L) and lycorine were normalized to reduce the level of glutathione and also to sustain the status of protein in erythrocytes during the peroxyl radical [2,2-azobis (2-amidinopropane) dihydrochloride (AAPH)] induced oxidative damage in ex vivo model. The present results of the investigations demonstrated that protective nature of the C. asiaticum (L) and lycorine will be considered as a significant natural antioxidant source.     

蛹虫草无性型菌丝体提取液体外抗氧化活性研究

分别测定了蛹虫草无性型菌丝体不同溶剂提取液在不同抗氧化模型中的抗氧化作用。结果表明,各种提取液对二苯基苦味酰基苯肼自由基(·DPPH)和羟自由基(·OH)均有显著的清除作用:在50mg/mL时,去离子水、70%乙醇和70%丙酮提取物对DPPH自由基的清除率分别为89.2%、83.6%和75.9%;70%乙醇提取物在30mg/mL时对·OH自由基的清除率达到100%;在50mg/mL时70%丙酮和去离子水提取物的·OH自由基清除率分别为95.6%和89.6%。在一定浓度下,各提取液对邻苯三酚自氧化也均有抑制作用;不同溶剂提取物的还原能力强弱为:70%乙醇>去离子水>70%丙酮。各种提取物的抗氧化组分不同,提取物浓度与抗氧化性成正相关。     

Physico-chemical characterization, antioxidant and anticancer activities in vitro of a novel polysaccharide from Melia toosendan Sieb. Et Zucc fruit

A novel water-soluble polysaccharide pMTPS-3, obtained from Melia toosendan Sieb. Et Zucc fruit by hot-water extraction and ethanol precipitation, was fractionated by DEAE-52 cellulose anion-exchange and Sephadex G-100 gel filtration chromatography. Its primary structural features and molecular weight were characterized by Fourier infrared spectrometry (FTIR), gel permeation chromatography (GPC) and gas chromatography (GC). And the antioxidant activities of pMTPS-3 in vitro were evaluated by 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging assay, superoxide radical scavenging assay and hydroxyl radical scavenging assay. The results suggested that pMTPS-3 was a heteropolysaccharide, composed of arabinose, glucose, mannose, and galactose in the molar ratio of 17.3:28.3:41.6:12.6 with molecular weight 26 100 Da. The purified pMTPS-3 was revealed to have notable scavenging activity against DPPH radical in a concentration-dependent manner and present a moderate inhibition of superoxide radicals with an IC₅₀ (5.6 mg/ml), and potent inhibiting power for hydroxyl radical compared with crude polysaccharide. Further, it exhibited strong inhibition effect in vitro on the growth of human gastric cancer BGC-823 cells. It is strongly evidenced that pMTPS-3 purified from the crude polysaccharides of Melia toosendan Sieb. Et Zucc could be explored as a potential antioxidant and therapeutics.     

3种百合鳞茎中多酚类物质的抗氧化活性分析

以野生百合渥丹、山丹和传统食用的兰州百合为研究对象,对其鳞茎中多酚类物质、11种单体酚的含量及抗氧化活性(ABTS自由基、超氧阴离子、羟自由基的清除能力,铜离子还原能力以及抑制脂质过氧化活性)进行了分析。结果表明:两种野生百合鳞茎中的多酚类物质含量及抗氧化活性均显著高于兰州百合。3种百合鳞茎中单体酚的种类也有所不同,但均含有没食子酸、矢车菊素-3-芸香糖苷、儿茶素、表儿茶素、杨梅酮、芦丁、对香豆酸、山奈酚。相关性分析显示,除对羟自由基的清除力外,各酚类物质总量与不同抗氧化指标之间呈显著正相关关系。试验结果认为,野生百合鳞茎可作为天然抗氧化资源应用于食品和医药业,具有一定的开发应用前景。     

Antioxidant Activity of Purified Protein Hydrolysates from Northern Whiting Fish (Sillago sihama) Muscle

In the present study, northern whiting fish (Sillago sihama) muscle was hydrolyzed with gastrointestinal enzymes (pepsin, trypsin and α-chymotrypsin) separately and the resulted protein hydrolysates were tested for antioxidant activities using DPPH radical scavenging activity and reducing power assays. The protein hydrolysate obtained from trypsin exhibited highest antioxidant activity. Further, it was fractionated by consecutive chromatography using anion exchange and gel filtration chromatography; the separated fractions were collected and evaluated for antioxidant activity. The results showed that fraction 2 exhibited high chelating activity (73.15 % at 0.5 mg/mL) and best radical scavenging activity for DPPH radical (55.16 % at 0.5 mg/mL), ABTS radical (57.98 % at 50 μg/mL), superoxide radical (39.55 % at 200 μg/mL) and hydroxyl radical (51.33 % at 100 μg/mL). In addition, the active fraction showed strong antioxidant activity in the inhibition of linoleic acid autooxidation (60 % at 0.5 mg/mL) and also it exhibited significant protective effect on DNA damage caused by hydroxyl radicals. The size of the active fraction was found to be <360.2 Da using mass spectroscopy. These results demonstrate that muscle protein hydrolysate from northern whiting fish could be a best alternative to produce natural antioxidant peptides.     

Comparison in antioxidant action between α-chitosan and β-chitosan at a wide range of molecular weight and chitosan concentration

Antioxidant activity in α- and β-chitosan at a wide range of molecular weight (Mw) and chitosan concentration (CS) was determined by 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, reducing ability, chelating ability, and hydroxyl radical scavenging activity. The form of chitosan (FC) had significant (P <0.05) effect on all measurements except DPPH radical scavenging activity, and antioxidant activity was dependent on Mw and CS. High Mw (280–300 kDa) of β-chitosan had extremely lower half maximal effective concentrations (EC₅₀) than α-chitosan in DPPH radical scavenging activity and reducing ability. The 22–30 kDa of α- and β-chitosan showed significantly (P <0.05) higher activities in DPPH radical scavenging, reducing ability, and hydroxyl radical scavenging than samples at other Mw, while chelating ability was the highest in 4–5 kDa chitosan. CS had significant effect on all measurements and the effect was related to Mw. The antioxidant activity of 280–300 kDa chitosan was affected by coil-overlap concentrations (C¹) in the CS range of 4–10 mg/mL, forming entanglements. Reducing ability and hydroxyl radical scavenging activity were more predominant action in antioxidant activity of chitosan as shown by the lower EC₅₀ values than those in other antioxidant measurements.     

Structure and protective effect of exopolysaccharide from P. Agglomerans strain KFS-9 against UV radiation

The water-soluble exopolysaccharide (WSEPS) from Pantoea agglomerans strain KFS-9 isolated from mangrove forest was prepared by removing bacterial cell from the fermentation liquid following by concentration and cold ethanol precipitation of the supernatant. The polysaccharide material was purified by gel permeation chromatography on a Sephacryl S-300HR column and characterized using chemical and spectral methods. The results show that WSEPS is protein-bound polysaccharide, and it is composed of arabinose, glucose galactose and gulcuronic acid in the molar ratio of 1.0:2.2:2.8:0.9. Their antioxidant activities in vitro were studied by various antioxidant assays, including hydroxyl radical scavenging, superoxide radical scavenging and antilipid peroxidation. The results show that the WSEPS extracted had a high antioxidant activity in a concentration-dependent manner (except the activity of antilipid peroxidation). WSEPS quenched hydroxyl radicals, superoxide radicals at low amounts, the IC(50) of which were 0.07 and 0.15 mg/ml, respectively. These results indicate that the protective effect of WSEPS against UV radiation is most likely to be due to the free radicals-scavenging ability.     

4种珍稀食用菌水提物的抗氧化活性研究

用DPPH自由基清除法、羟基自由基清除法和超氧阴离子自由基清除法对4种珍稀食用菌灵芝、云芝、茶树菇、松茸的水提物进行抗氧化活性评价,为更好评价其抗氧化活性,以维生素C作为阳性对照。实验结果显示：4种食用菌水提物具有不同程度的抗氧化活性。云芝对DPPH自由基的清除能力最强,其IC₅₀值为1.46 mg/mL,维生素C清除DPPH自由基的IC₅₀为0.046 mg/mL;茶树菇对清除羟基自由基的清除能力最强,其IC₅₀值为1.41 mg/mL,云芝和松茸也有较强清除羟自由基能力,其IC₅₀值分别为1.56、1.57 mg/mL,三者的清除能力均明显优于阳性对照样品,维生素C清除羟自由基的IC₅₀为2.41 mg/mL;灵芝和云芝有较强清除超氧阴离子自由基能力,其IC₅₀值分别为124.48、138.28 mg/mL。     

青橄榄浸膏的提取及其抗氧化活性研究

为优化青橄榄浸膏提取工艺,并探讨其抗氧化性。以茂名盛产的青橄榄为原料,采用超声波辅助乙醇提取法,以总黄酮和总多酚得率为评价指标,考察各因素对青橄榄浸膏提取效果的影响。采用邻苯三酚自氧化法、结晶紫法和DPPH清除能力评价青橄榄浸膏的抗氧化活性。结果显示,浸膏的最佳提取工艺为:乙醇体积分数70%,料液比1∶18 (g∶mL),超声提取温度50℃,时间6 min(超声提取阶段);单纯有机溶剂提取温度60℃,时间45 min(有机溶剂浸提阶段);此条件下总黄酮得率为1. 76%,总多酚得率为15. 53%。终产物浸膏在0. 3 mg/mL浓度下对超氧阴离子自由基抑制率为22. 74%,相当于同等质量浓度的抗坏血酸抑制效果的23. 47%;在0. 02 mg/mL浓度下对羟基自由基的清除率为67. 32%,相当于同等质量浓度的抗坏血酸清除效果的112. 58%;在0. 2 mmol/mL的DPPH溶液体系中,0. 15 mg/mL的浸膏对DPPH的清除率为95. 40%,相当于同等质量浓度的抗坏血酸清除效果的140. 83%;总体来讲,浸膏具有良好的抗氧化能力,虽然对超氧阴离子自由基抑制率弱于抗坏血酸,但羟基自由基的清除率及DPPH清除率均优于抗坏血酸。     

枇杷花茶水提物的镇咳、抗炎与抗氧化作用研究

采用小鼠氨水致咳法研究枇杷花茶水提物镇咳效果,以二甲苯致小鼠耳肿胀法研究其抗炎效果,并从枇杷花茶的还原能力及对超氧阴离子和羟自由基的清除作用分析枇杷花茶水提物的抗氧化效果。结果表明,枇杷花茶的水提物高剂量组(3000 mg·kg-1)、低剂量组(700 mg·kg-1)均有镇咳抗炎效果,水提物的浓度越高,效果越好。各浓度枇杷花茶水提物均表现出一定的还原能力,对于羟基自由基和超氧阴离子都有一定的清除效果。其中,20 mg·mL-1水提物还原效果最好(吸光值0.903),超过0.2 mg·mL-1抗坏血酸(吸光值0.814);10 mg·mL-1的水提物对超氧阴离子的清除率为47.32%;20 mg·mL-1水提物对于羟基自由基的清除效果非常明显,清除率为91.62%。枇杷花茶水提物镇咳、抗炎、抗氧化效果明显。     

Antiproliferative and antioxidant properties of nematocysts crude venom from jellyfish Acromitus flagellatus against human cancer cell lines

This study aimed to investigate the antiproliferative and antioxidant properties of crude venom from the nematocyst of Jellyfish Acromitus flagellates on human lung cancer (A549) and liver cancer (HepG2) cell lines. The prepared crude venom was subjected to analyses of the biochemical constituents, protein profiles, antioxidant and anticancer activities by standard methods. The extracted venom was pale-yellow in color and viscous/sticky. The biochemical composition such as, protein (1.547 mg/ml), lipid (0.039 mg/ml) and carbohydrate (0.028 mg/ml) was estimated. Protein profiles were determined by SDS PAGE, the result revealed that the molecular weight range from 205 ? 3.5 kDa. The free radical scavenging activity was analyzed by the reducing potential (56.36%), DPPH (72.47%), hydroxyl (68.50%), superoxide anion (65.75%), and nitric oxide (33.04%). The cell viability was observed by using different concentrations (20 to 100 µg/ml) of crude venom on A549 and HepG2 cancer cell lines and the IC₅₀ values were recorded in (60 μg/ml and 40 μg/ml) respectively, while it had none cytotoxic effects on Vero cell line up to the concentration of 90 μg/ml. These results suggest that crude venom from nematocyst of A. flagellatus possesses anti-cancer activity and able to develop novel drugs on marine-derived compounds.     

Free radical and reactive oxygen species scavenging activities of the extracts from seahorse, Hippocampus kuda Bleeler

Seahorse, Hippocampus kuda (SH) a marine teleost fish, is well known not only for its special medicinal composition and used as one of the most famous and expensive materials of traditional Chinese medicine. It was extracted with water (SHW), methanol (SHM), and ethanol (SHE), respectively and evaluated by various antioxidant assays. The including reducing power, total antioxidant, DPPH radical scavenging, hydroxyl radical scavenging, superoxide anion radical scavenging, alkyl radical scavenging, and protective effect on DNA damage caused by hydroxyl radicals generated. Further, the ROS level was detected using a fluorescence probe, 2′,7′-dichlorofluorescin diacetate (DCFH-DA), which could be converted to highly fluorescent dichlorofluorescein (DCF) with the presence of intracellular ROS on mouse macrophages, RAW264.7 cell and inhibited myeloperoxidase (MPO) activity in human myeloid, HL60 cells, respectively. Those various antioxidant activities were compared to standard antioxidants such as α-tocopherol. Among SHM exhibited the highest antioxidant activity in linoleic acid system, effective reducing power, DPPH radical scavenging, hydroxyl radical scavenging, superoxide radical scavenging, alkyl radical scavenging, inhibitory intracellular ROS, and inhibited MPO activity. Furthermore, MTT assay showed no cytotoxicity on mouse macrophages cell (RAW264.7) and human cell lines (MRC-5, HL60, U937). This antioxidant property depends on concentration and increasing with increased amount of extracts. The results obtained in the present study indicated that the see horse (Hippocampus kuda Bleeker) is a potential source of natural antioxidant.     

Melanogenesis inhibitory effect of low molecular weight fucoidan from <Emphasis Type="Italic">Undaria pinnatifida</Emphasis>

In this study, fucoidans with different molecular weight that were isolated from the brown alga Undaria pinnatifida (Phaeophyceae, Laminariales) were investigated for their ability to inhibit melanogenesis and scavenge superoxide and hydroxyl radicals. Fucoidan samples with low molecular weights of 89, 35, 17, and 6 kDa were prepared by radiation-degradation of a 378 kDa fucoidan isolated from U. pinnatifida. The inhibitory activity of fucoidan against melanin biosynthesis in B16BL6 melanoma cells was enhanced for low molecular weight samples. To investigate the increase in melanogenesis inhibition exhibited by the low molecular weight fucoidan, tyrosinase inhibition activity and radical scavenging activities were measured. There was an increase in the tyrosinase inhibition activity for low molecular weight samples. Additionally, the radical scavenging activity was increased for lower molecular weight fucoidans. These results suggest that low molecular weight fucoidans from seaweeds may have beneficial biological properties.     

Evaluation of in vitro antioxidant,antimicrobial, genotoxic and anticancer activities of lichen Cetraria islandica

In this study, the antioxidant, antimicrobial, genotoxic and anticancer activities of Cetraria islandica methanol extract were determined by using free radical and superoxide anion scavenging activity, reducing power, determination of total phenolic compounds and flavonoid contents, broth microdilution minimal inhibitory concentration against five bacterial and five fungal species, cytokinesis block micronucleus (MN) assay on peripheral blood lymphocytes (PBLs) and the microculture tetrazolium test on FemX (human melanoma) and LS174 (human colon carcinoma) cell lines. As a result of the study, we found that C. islandica methanol extract exhibited moderate free-radical-scavenging activity with IC₅₀ values 678.38 μg/ml. Moreover, the tested extract had effective reducing power and superoxide anion radical scavenging. The minimal inhibitory concentration values against the tested microorganisms ranged from 0.312 to 5 mg/ml. The extract increased MN frequency in a dose dependent manner, but it was significant in higher tested concentrations (50, 100 and 200 μg/ml). No significant differences were observed between NDI values in all treatments and untreated PBLs. In addition, the tested extract had strong anticancer activity towards both cell lines with IC₅₀ values of 22.68 and 33.74 μg/ml. It can be concluded that the tested extract exhibited a certain level of in vitro antioxidant, antimicrobial, genotoxic and anticancer activities.     

Antioxidant and antiviral activities ofEuphorbia thymifolia L.

The antioxidant and antiviral activities ofEuphorbia thymifolia L. (Euphorbiaceae) were investigated in this study. The results showed that all of the fractions (MeOH, CHCl₃, EtOAc, n-butanol and water) and pure compounds (3-O-galloyl-4,6-(S)-HHDP-D-glucose, rugosin B and 1,3,4,6-tetra-O-galloyl-K--D-glucose)tested possessed antioxidant activities, with the exception of the organic aqueous fraction in the anti-lipid and anti-super-oxide formation assays. The range of IC₅₀ of anti-lipid formation, anti-superoxide formation and free radical scavenging assays for all fractions and pure compounds were 2.81–7.63, 0.03–2.18 and 0.013–2.878 mg/ml, respectively. Electron spin resonance studies showed that water extract and pure compounds ofE. thymifolia exhibited superoxide radical and hydroxyl radical scavenging activities. Besides antioxidant activities, 3-O-galloyl-4,6-(S)-HHDP-D-glucose and EtOAc fraction also showed anti-HSV-2 activity. Thus,E. thymifolia was concluded to possess antioxidant and anti-HSV-2 activities.     

Preparation and evaluation of antioxidant peptides from ethanol-soluble proteins hydrolysate of Sphyrna lewini muscle

To get high yield of ethanol-soluble proteins (EP) and the antioxidant peptides from Sphyrna lewini muscle, orthogonal experiments (L(9)(3)(4)) were applied to optimize the best extraction conditions and enzyme hydrolysis conditions. The yield of EP reached 5.903±0.053% under the optimum conditions of ethanol concentration 90%, solvent to material ratio 20:1, extraction temperature of 40°C and extraction time of 80min. The antioxidant SEPH (EP hydrolysate of S. lewini muscle) was prepared by using papain under the optimum conditions of enzymolysis time 2h, total enzyme dose 1.2%, enzymolysis temperature 50°C and pH 6, and its DPPH radical scavenging activity reached 21.76±0.42% at the concentration of 10mg/ml. Two peptides (F42-3 and F42-5) were isolated from SEPH by using ultrafiltration, anion-exchange chromatography, gel filtration chromatography and RP-HPLC. The structures of F42-3 and F42-5 were identified as Trp-Asp-Arg and Pro-Tyr-Phe-Asn-Lys with molecular weights of 475.50Da and 667.77Da, respectively. F42-3 and F42-5 exhibited good scavenging activity on hydroxyl radical (EC(50) 0.15mg/ml and 0.24mg/ml), ABTS radical (EC(50) 0.34mg/ml and 0.12mg/ml), and superoxide anion radical (EC(50) 0.09mg/ml and 0.11mg/ml), but moderate DPPH radical (EC(50) 3.63mg/ml and 4.11mg/ml). F42-3 and F42-5 were also effectively against lipid peroxidation in the model system and peroxyl free radical scavenging in β-carotene linoleic acid assay. Their high activities were due to the smaller size and the presence of antioxidative amino acids within the peptide sequences.     

Cloning,expression and antioxidant activity of a novel collagen from <Emphasis Type="Italic">Pelodiscus sinensis</Emphasis>

Collagen is the main structural protein of various connective tissues in animals and naturally plays an important role within the body. It is increasingly used within certain areas, such as medicine, citology and cosmetology. The soft-shelled turtle (Pelodiscus sinensis) is a commercially important aquatic species rich in collagen. In this study, a novel collagen gene fragment of 756 bp, which encodes 252 deduced amino acid residues, including 25 conserved Gly-X-Y motifs, was cloned from a soft-shelled turtle. Recombinant soft-shelled turtle collagen (rSTC) was stably expressed in Escherichia coli Rosetta and purified by His GraviTrap affinity columns. The antioxidant activities of rSTC were measured using hydroxyl and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals. The results showed that rSTC quenched the free radicals in a dose-dependent manner. The hydroxyl radical scavenging activity (HRSA) of rSTC was 98.9 % at a concentration of 3 mg/mL. At a concentration of 5 mg/mL, rSTC exhibited a DPPH radical scavenging activity of 32.7 %. At the tested concentrations, rSTC exhibited higher HRSA and lower DPPH radical scavenging activity.     

In vitro antioxidant activity of Diospyros malabarica Kostel bark

Antioxidant activity of defatted methanol extract of D. malabarica bark was studied for its free radical scavenging property on different in vitro models e.g. 1,1-diphenyl-2-picryl hydrazyl (DPPH), nitric oxide, superoxide, hydroxyl radical and lipid peroxide radical model. The extract showed good dose-dependent free radical scavenging property in all the models except in hydroxyl radical inhibition assay. IC50 values were found to be 9.16, 13.21, 25.27 and 17.33 microg/ml respectively in DPPH, nitric oxide, superoxide and lipid peroxidation inhibition assays. In hydroxyl radical inhibition assay 1000 microg/ml extract showed only 10% inhibition with respect to the control. Measurement of total phenolic compounds by Folin-Ciocalteu's phenol reagent indicated that 1 mg of the extract contained 120.7 microg equivalent of pyrocatechol. The results indicate that the antioxidant property of the extract may be due to the high content of phenolic compounds. However, the underlying mechanism may not involve hydroxyl radical scavenging property.