• Title/Summary/Keyword: radical scavenging activity

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Preparation and Antioxidant Activities In Vitro of a Designed Antioxidant Peptide from Pinctada fucata by Recombinant Escherichia coli

  • Wu, Yanyan;Ma, Yongkai;Li, Laihao;Yang, Xianqing
    • Journal of Microbiology and Biotechnology
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    • v.28 no.1
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    • pp.1-11
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    • 2018
  • An antioxidant peptide derived from Pinctada fucata meat using an Alcalase2.4L enzymatic hydrolysis method (named AOP) and identified by LC-TOF-MS has promising clinical potential for generating cosmetic products that protect skin from sunshine. To date, there have been few published studies investigating the structure-activity relationship in these peptides. To prepare antioxidant peptides better and improve their stability, the design and expression of an antioxidant peptide from Pinctada fucata (named DSAOP) was studied. The peptide contains a common precursor of an expression vector containing an ${\alpha}$-helix tandemly linked according to the BamHI restriction sites. The DNA fragments encoding DSAOP were synthesized and subcloned into the expression vector pET-30a (+), and the peptide was expressed mostly as soluble protein in recombinant Escherichia coli. Meanwhile, the DPPH radical scavenging activity, superoxide radical scavenging activity, and hydroxyl radical scavenging activity of DSAOP $IC_{50}$ values were $0.136{\pm}0.006$, $0.625{\pm}0.025$, and $0.306{\pm}0.015mg/ml$, respectively, with 2-fold higher DPPH radical scavenging activity compared with chemosynthesized AOP (p < 0.05), as well as higher superoxide radical scavenging activity compared with natural AOP (p < 0.05). This preparation method was at the international advanced level. Furthermore, pilot-scale production results showed that DSAOP was expressed successfully in fermenter cultures, which indicated that the design strategy and expression methods would be useful for obtaining substantial amounts of stable peptides at low costs. These results showed that DSAOP produced with recombinant Escherichia coli could be useful in cosmetic skin care products, health foods, and pharmaceuticals.

Mineral, Nutritional, and Phytochemical Profile, Total Phenolic Content, and Radical Scavenging Activity of Philippine Bamboo "Bolo" Gigantochloa levis (Blanco) Merr. Leaves

  • Tongco, Jovale Vincent V.;Rodriguez, Evelyn B.;Abasolo, Willie P.;Mun, Sung Phil;Razal, Ramon A.
    • Natural Product Sciences
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    • v.22 no.1
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    • pp.60-63
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    • 2016
  • The study is a pioneering effort to determine the mineral, nutritional, and phytochemical composition and phenolic content and to determine the free radical scavenging activity of Gigantochloa levis (Blanco) Merr, a native bamboo species (locally known as "bolo") in the Philippines. Proximate analysis showed that air-dried G. levis leaves contain 15.8% ash, 22.6% crude protein, 1.2% crude fat, 29.3% crude fiber, and 19.7% total sugar. Phytochemical tests indicated the presence of diterpenes, triterpenes, saponins, phenols, tannins, and flavonoids in both the ethanolic and aqueous leaf extracts, while phytosterols were only detected in the ethanolic extract. Folin-Ciocalteu assay determined the total phenolic content in gallic acid equivalents (GAE) to be $85.86{\pm}3.71$ and $32.32{\pm}1.01mg\;GAE/100g$ dried sample for the ethanolic and aqueous extracts, respectively. The total phenolic content in quercetin equivalents (QE) was $74.44{\pm}3.11$ and $29.43{\pm}0.85mg\;QE/100g$ dried sample for the ethanolic and aqueous extracts, respectively. The radical scavenging activity of the different solvent fractions containing varying concentrations of the extract was determined using the 2, 2-diphenyl-1-picrylhydrazyl (DPPH) assay. The ethyl acetate and 1-butanol fractions were found to have the highest radical scavenging activity. Mineral analysis via Energy Dispersive X-Ray Spectrometry (EDS) of the ash of G. levis leaves showed that Si is the major component, followed by K and Mg. These results point to the potential of G. levis leaves as a source of minerals and bioactive compounds with medicinal value.

Antioxidant Activities and α-Glucosidase Inhibitory Effect of Water Extracts from Medicinal Plants (약용식물 물 추출물의 항산화 활성 및 α-Glucosidase 저해효과)

  • Kim, Hyun Sook;Kim, Tae Woo;Kim, Dae Jung;Lee, Jae Sung;Kim, Kyoung Kon;Choe, Myeon
    • Korean Journal of Medicinal Crop Science
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    • v.21 no.3
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    • pp.197-203
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    • 2013
  • We studied the total polyphenol content, DPPH radical scavenging activity, hydroxyl radical scavenging activity and ${\alpha}$-glucosidase inhibition of water extracts from 17 medicinal plants. Total polyphenol contents ranged from 10.0 (Coix lachryma-jobi L, CL) ~ 279.7 (Perilla sikokiana, PS)mg/g. The water extract from medicinal plants were evaluated for its free radical scavenging activities and compared with a commercial antioxidant, ascorbic acid. DPPH radical scavenging activity of Pyrus pyrifolia (PP), Chamaecyparis obtusa L. (COL), Chamaecyparis obtusa F. (COF), and PS were higher than positive control. Higher hydroxyl radical scavenging activity were shown in Acanthopanax senticosus (AS) and Cordyceps militaris (CM) than the other plants. The highest anti-${\alpha}$-glucosidase activity was observed in Cornus officinalis (CO) and Paeonia suffruticosa Andrews (PSA) water extracts. PSA showed not only the higher DPPH radical scavenging activity but also the anti-${\alpha}$-glucosidase activity. The results of our study that PP, COL, COF, PS, AS, CM, CO and PSA could be potential candidates for natural antioxidants.

Antioxidant Constituents from the Stem of Sorghum bicolor

  • Kwon, Yong-Soo;Kim, Chang-Min
    • Archives of Pharmacal Research
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    • v.26 no.7
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    • pp.535-539
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    • 2003
  • The EtOAc soluble fraction from the stem of Sorghum bicolor showed a strong free radical scavenging activity. Five major compounds were isolated from this fraction. They were identified by spectral data as methyl ferulate (1), methyl p-hydroxycinnamate (2), p-hydroxybenzaldehyde (3), tricin (4), and quercetin 3,4 -dimethyl ether (5). Among these compounds, 1 exhibited a strong, free radical scavenging activity on 1, 1-diphenyl-2-picrylhydrazyl (DPPH) with an $IC_50$ value of 0.7 $\mu$M. We further studied the effects of these isolated compounds on the lipid peroxidation in rat liver microsomes induced by non-enzymatic method. All five compounds showed anti-lipid peroxidation activity ($IC_50$ values of 0.5, 0.4, 0.3 and 0.3 $\mu$ M, respectively).

Free Radical Scavenging Activity and Protective Ability of Methanolic Extract from Duchesnea indica Against Protein Oxidation and DNA Damage

  • Hu, Weicheng;Shen, Wei;Wang, Myeong-Hyeon
    • Preventive Nutrition and Food Science
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    • v.14 no.4
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    • pp.277-282
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    • 2009
  • The antioxidant potency of methanolic extract of Duchesnea indica (MDI; Indian strawberry) was investigated by employing various established in vitro systems, such as total phenolic content, 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity, reducing power assay, metal chelating assay, superoxide radical scavenging activity and protective ability of DNA damage and protein oxidation. MDI inhibited metal chelating by 75.57% at 2 mg/mL, scavenged 50% DPPH free radical at 29.13 ${\mu}$g/mL, and eliminated approximately 46.21% superoxide radical at the concentration of 1 mg/mL. In addition, MDI showed strong ability on reducing power, DNA damage protection and protein oxidation protection. Overall, results suggested that MDI might be beneficial as a potent antioxidant and effectively employed as an ingredient in food applications.

Antioxidant and Free Radical Scavenging Activity of Different Fractions from Hawthorn Fruit

  • Park, Jae-Hyo;Li, Chunmei;Hu, Weicheng;Wang, Myeong-Hyeon
    • Preventive Nutrition and Food Science
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    • v.15 no.1
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    • pp.44-50
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    • 2010
  • Hawthorn fruit is a conventional medicine used in treating cardiovascular diseases. Its therapeutic effects may relate to its antioxidant compounds. In this study, we evaluated the antioxidant activity of $CH_2Cl_2$, EtOAc, n-butanol and water fractions from 70% methanolic hawthorn fruit extract by total phenolic and flavonoid contents, total antioxidant activity, DPPH free radical scavenging activity, superoxide radical scavenging activity, reducing power assay, lipid peroxidation inhibitory activity and protective effect against hydroxyl-radical-induced DNA damage. Results showed that the EtOAc fraction contained significantly greater antioxidant activities than other fractions, which suggests that the potent EtOAc fraction should be used for further studies to identify the antioxidant compounds.

Free Radical Scavenging Activity of Enzymatic Hydrolyzates of Hot Water Extract from the Shell of Reeve's Turtle (Chinemys reevesii)

  • Je, Jae-Young;Kim, Eun-Kyung;Park, Pyo-Jam;Kang, Mi-Kyung;Ahn, Chang-Bum
    • Fisheries and Aquatic Sciences
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    • v.11 no.2
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    • pp.71-75
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    • 2008
  • The shell of Reeve's turtle has been used as a traditional folk medicine in Korea. We produced a hot water extract from Reeve's turtle shell according to the traditional medical practice. To release bioactive peptides, the hot water extract was enzymatically hydrolyzed with various proteases, and the free radical scavenging activity of the hydrolysate was investigated against 1,1-diphenyl-2-picryl-hydrazyl (DPPH), hydroxyl and peroxyl radicals. The free radical scavenging activity of the enzymatic hydrolysates varied from 1 to 79% depending on the enzymes, free radical species, and concentration. The $EC_{50}$ values demonstrated that the enzymatic hydrolysates of hot water extract from the shell of Reeve's turtle are potential antioxidants.

Biological screening of 100 plant extracts for cosmetic use (1) Antioxidative activity and free radical scavenging activity

  • Kim, Jeong-Ha;Kim, Beom-Jun;Seok, Chung-Hyun;Won, Il;Kim, Jeong-Haeng;Kim, Hyun-Pyo;Heo, Moon-Young
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.22 no.2
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    • pp.115-123
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    • 1996
  • Methanolic aqueous extracts of 100 plants were screened for antioxidative activity using Fenton's reagen/ethyl linoeate system and free radical scavenging activity using DPPH free radical generating system. The results suggest that at least six plants including Eugenia caryophyllata, Alpinia offiicinarum, Rhus verniciflua, Curcuma longa, Rheum palmatvm and Evodia officinalis may be the potential sources of antioxidant, But only one plant, Cornus officinalis, may be the potential source of free radical scavenger from natural plants.

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The Radical Scavenging Effects of Stilbene Glucosides from Polygonum multiflorum

  • Ryu, Geon-Seek;Ju, Jeung-Hoon;Park, Yong-Ju;Ryu, Shi-Yong;Choi, Byoung-Wook;Lee, Bong-Ho
    • Archives of Pharmacal Research
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    • v.25 no.5
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    • pp.636-639
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    • 2002
  • The extract of the root of Polygonum multiflorum exhibited a significant antioxidant activity assessed by the DPPH radical scavenging activity in vitro. The bioassay-guided fractionation of the extract yielded a stilbene glucoside, (E)-2,3,5,4'-tetrahydroxystilbene-2-Ο-$\beta$-d-glucopyranoside (1) as an active constituent responsible for the antioxidant property. Compound 1 demonstrated a moderate DPPH radical scavenging activity ($IC_{50}$, 40 $\mu$M), while the corresponding deglucosylated stilbene 2 exhibited a much higher activity ($IC_{50}$, 0.38 $\mu$M).

Influence of pH on the Antioxidant Activity of Melanoidins Formed from Different Model Systems of Sugar/Lysine Enantiomers

  • Kim, Ji-Sang;Lee, Young-Soon
    • Food Science and Biotechnology
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    • v.17 no.6
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    • pp.1310-1315
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    • 2008
  • This study was to investigate the influence of pH on the antioxidant activity of melanoidins formed from glucose (Glc) and fructose (Fru) with lysine enantiomers in the Maillard reaction. Melanoidins formed from D-isomers were found to be effective antioxidants in different in vitro assays with regard to the ferrous ion chelating activity, 1, l-diphenyl-2-picryl-hydrazil (DPPH) radical scavenging activities, ferric reducing/antioxidant power (FRAP), and 2,2'-azinobis(3-ethylbenothiazoline-6-sulfonic acid) diammonium salt (ABTS) radical scavenging activity. In particular, the chelating activity of these melanoidins at a pH of 7.0 was greater than those with pH of 4.0 and 10.0. The chelating activity and DPPH radical scavenging activity of the melanoidins formed from the Glc systems were higher than those of the melanoidins formed from the Fru systems. However, the FRAP and ABTS radical scavenging activity of these melanoidins were not different according to pH level, with exceptions being the Fru systems.