DPPH Free Radical Scavenging Ability Research Articles

Characteristics and upregulation of antioxidant capacity of fermented pueraria starch production wastewater with kombucha consortium

Pueraria lobata is a traditional plant used for both medicine and food. Pueraria starch has a long history of folk consumption in China. The processing of pueraria starch produces a lot of waste water and is often discarded, but it contains rich nutrients and is suitable for the growth of microorganisms. In this study, pueraria starch processing wastewater was used as a new fermentation substrate for kombucha fungus to develop a new functional beverage. After 8 days of static fermentation in 28 °C, the pH of kombucha fermented with pueraria starch processing wastewater as substrate decreased to 2.78, the total acid concentration was 0.158 mol/L, and the mass concentration of reducing sugar decreased to 2.05 mg/mL. The pueraria starch production wastewater before and after fermentation was extracted with 80% methanol and the mass concentration of total flavonoids was determined. The antioxidant activity of pueraria starch processing wastewater before and after fermentation was analyzed by using three antioxidant models: DPPH free radical scavenging ability, ABTS cationic free radical scavenging ability and ferrous ion reducing power. The results showed that after 7 days of fermentation, the mass concentration of total flavonoids in kombucha produced by the pueraria starch processing wastewater was 268.45 mg/L. The antioxidant activity of fermented kombucha beverage was significantly higher than that of unfermented pueraria starch processing wastewater. This study provides a new way for the resource utilization of Pueraria starch processing wastewater.

Chemical and biological characterization of essential oils extracted from citrus fruits peels

In Morocco, citrus fruits processing produces large quantities of waste and by-products, which represent 50% to 60% of the fresh mass of fruit. In eastern Morocco, generally citrus processing by-products ends up being thrown in the public landfill. These by-products are rich in bioactive compounds such as antioxidants and essential oils. The objective of this study is the chemical and biological characterization of essential oils extracted from citrus peels of four species, including Lemon (Citrus limon), Bitter orange (Citrus aurantium), Berkane clementine (Citrus Clementina) and Navel, a species of orange (Citrus sinensis). The efficiency of two extraction techniques used, hydro-distillation (Traditional method) and microwave assisted extraction (Eco-friendly green method), is highlighted by comparing yields of essential oils (EOs). Thus microwave assisted extraction green method has shown the highest yields ranging from 10,47% (Clementine) to 11,5% (Navel). While by hydrodistillation, the yield of (OE) did not exceed (5,95%). Besides, chemical composition and antioxidant activity of EOs of the four citrus were studied. Thus, the CPG-MS analyzes identified some twenty minor compounds and the D-limonene as the major constituent with contents generally greater than 55% and which reached almost (97,12%). In the case of EO of Lemon (Citrus lemon), the antioxidant activity was determined by the DPPH free-radical scavenging ability, the highest antioxidant activity (44,45%) is registered in the Navel’s EO, and the lowest was observed in the Bigarade’s EO (10,66%). In addition, antimicrobial activity was tested, EOs of lemon have shown the strongest antifungal power with values of 35 mm of antagonistic effect, but no antibacterial activity was detected for the four types of Eos. These EOs would be of interest in both agriculture and the food industry by acting as bio-fungicide but also as additives for compounds of medical and cosmetic interest.

Isolation of Neuroprotective Anthocyanins from Black Chokeberry (Aronia melanocarpa) against Amyloid-β-Induced Cognitive Impairment.

Black chokeberry (Aronia melanocarpa) fruits are rich in anthocyanins, which are vital secondary metabolites that possess antioxidative properties. The aim of this study was to isolate and purify the anthocyanins from black chokeberry by simulated moving bed (SMB) chromatography, and to investigate the neuroprotective effect of SMB purified anthocyanin against Aβ-induced memory damage in rats. The parameters of the SMB process were studied and optimized. Anthocyanin extracts were identified by HPLC and UPLC-QTOF-MS, and antioxidant abilities were evaluated. The Aβ-induced animal model was established by intracerebral ventricle injection in rat brain. Through the SMB purification, anthocyanins were purified to 85%; cyanidin 3-O-galactoside and cyanidin 3-O-arabinoside were identified as the main anthocyanins by UPLC-QTOF-MS. The SMB purified anthocyanins exhibited higher DPPH and ABTS free radical scavenging abilities than the crude anthocyanins extract. Furthermore, rats receiving SMB purified anthocyanins treatment (50 mg/kg) showed improved spatial memory in a Morris water maze test, as well as protection of the cells in the hippocampus against Aβ toxicity. These results demonstrate that anthocyanins could serve as antioxidant and neuroprotective agents, with potential in the treatment of Alzheimer’s disease.

Identification of novel C-2 symmetric Bis-Azo-Azamethine molecules as competitive inhibitors of mushroom tyrosinase and free radical scavengers: synthesis, kinetics, and molecular docking studies

Tyrosinase is a multi-copper enzyme found in plants, animals and microorganisms, plays a critical role in the melanogenesis and browning process critical to cosmetics and food industries. Many natural, semi-synthetic and synthetic inhibitors have been discovered. To this end, a small library of symmetrical Bis-Azo-Azamethine hybrids 5a–j was synthesized and characterized through spectroscopic and analytical data and explored for mushroom tyrosinase and free radical scavenging activity. All of the molecules 5a–j explicated better potential compared to the standard Kojic acid. On the whole, compound 5i having IC50 value 0.002 ± 0.004 µM was found to be the most potent derivative. The Kinetic studies were performed for 5i and indicating the mode of inhibition in a competitive manner. Structure Activity Relationship (SAR) analysis and docking studies were carried out. Thus compound 5i bearing bulky naphthyl groups was most potent and, The molecular docking indicated formation of two hydrogen bonds with Arg268 and one hydrophobic interaction with Glu322. The carbonyl oxygen of 5i interacts with Arg268 and form two hydrogen bonds having lengths 2.44 and 2.62 Å, respectively. In the same way, compounds 5a–j were appraised for DPPH free radical scavenging ability and five of them 5d, 5e, 5h, 5i and 5j were found to exhibit higher % scavenging potency compared with vitamin C, as the standard. Interesting compound 5i was again the most potent in the series. The current investigation points towards the role of naphthyl group in design of new inhibitors of melanogenesis and the antioxidants with improved efficacy. Communicated by Ramaswamy H. Sarma

Analysis of antioxidant property of the extract of saponin by experiment design methodology

The antioxidant properties of the extract of saponin from Sapindus mukorossi (soapberry) were analyzed and optimized using Response Surface Methodology (RSM). Based on this study, by using different methods to evaluate its antioxidant properties for further analysis. The methods are 1,1-di-phenyl-2-picryl-hydrazyl (DPPH) free radical scavenging assay, reducing power, and ferrous ion chelating ability. The best DPPH free radical scavenging ability was obtained at 91.56 % (X1 = 1 hour, X2 = 1:15 (w/v), X3 = 0.55 %), in which, the influences of solid to liquid ratio (X2) and enzyme concentration (X3) was found to be significant on the response of percentage of free radical scavenging effect (Y1). The best reducing power was obtained in Absorbance (Abs) 0.473 (X1 = 3 hour, X2 = 1:10 (w/v), X3 = 0.1 %), in which, the influences of solid to liquid ratio (X2) was found to be significant on the response of amount of reducing power (Y2). The best ferrous ion chelating ability was obtained at 49.63 % (X1 = 1 hour, X2 = 1:10 (w/v), X3 = 1 %), in which, the influence of time (X1) and solid to liquid ratio (X2) was significant on the response of percentage of ferrous ion chelating ability (Y3). The extract of saponin from Sapindus mukorossi shows excellent in antioxidant capacity based on the reducing power and scavenging free radicals activity, but it is relatively weak in ferrous ion chelating.

Screening and application of lactic acid bacteria and yeasts with l-lactic acid-producing and antioxidant capacity in traditional fermented rice acid.

In the study, Lactobacillus paracasei H4‐11, Lactobacillus fermentum D1‐1, Lactobacillus casei H1‐8, Lactobacillus reuteri H2‐12, and Kluyveromyces marxianus L1‐1 were screened from traditional fermented rice acid based on several indicators: L‐lactic acid production capacity (13.46 ~ 19.69 g/kg), antioxidant capacity (DPPH clearance ability of 35.36 ~ 56.89%), and savory flavor indicators. Glutinous rice, quinoa, barley rice, and brown rice were selected to carry out rice acid fermentation. Different viable lactic acid bacteria and yeasts were screened, respectively, in the saccharification, acidification, alcoholization, and late acidification stages. Rice acid fermented with L. paracasei H4‐11 and K. marxianus L1‐1 in glutinous rice showed the high L‐lactic acid content (23.09 g/kg). The DPPH free radical scavenging ability in rice acid fermented with L. fermentum D1‐1 and L. paracasei H4‐11, respectively, reached 34.27% and 33.05% in 96 hr. Although quinoa rice acid had the highest L‐lactic acid content (33.74 g/kg) and the DPPH free radical scavenging ability (60.10%), it had the poor taste due to the high astringency intensity and bitter intensity. Rice acid fermented with both L. paracasei H4‐11 and K. marxianus L1‐1 in glutinous rice showed the highest savory flavor and had the lowest astringency and bitter. L. paracasei H4‐11 and K. marxianus L1‐1 were the potential strains for the fermentation of rice acid. These results promote the industrial development of Chinese rice acid.Practical applicationsRice acid as a functional nondairy fermented product is widely accepted by Chinese consumers. However, rice acid fermentation is still a traditional spontaneous process, which causes instability in its flavor and quality. Lactobacillus paracasei H4‐11 and Kluyveromyces marxianus L1‐1 screened in this study contributed to the improvements in the flavor and antioxidant capacity of rice acid. In addition, glutinous rice was confirmed as the suitable fermentation material of rice acid in the study.

Enhancement of antioxidant effect of pitaya by lactic acid bacteria fermentation

Pitaya has received a great deal of consumer interest for its large amount of micronutritions. This study investigated the changes of total phenols and total flavonoids of fermented pitaya, as well as the antioxidant abilities. The results showed that fermentation could significantly increase the counts of water-soluble phenols and flavonoids. After being fermented for 24h, the DPPH free radical, hydroxyl radical and superoxide anion scavenging ability raised significantly. Reducing power of fermented pitaya also increased remarkably. Thus, fermentation could increase the antioxidant ability of pitaya, and could be a potential process for pitaya products.

Development and characterization of corn starch/PVA active films incorporated with carvacrol nanoemulsions

An active film was prepared by corn starch (CS), polyvinyl alcohol (PVA) and carvacrol nanoemulsions (CNE). The microstructure and properties of CNE/corn starch/PVA (CNE/CSP) films were characterized and investigated. Scanning electron microscopy (SEM) revealed the uniform distribution of CNE and discontinuity of the film matrix. Fourier transform infrared (FT-IR) and rheological analysis indicated that CNE could weaken molecular interaction of the film matrix. X-ray diffraction (XRD) show that the films are amorphous and CNE has no effect on crystal structure of the films. Incorporation of CNE significantly increased the tensile strength, Young's modulus, elongation at break, barrier (water vapor and ultraviolet), antioxidant and antifungal activity. With the CNE incorporated, the optimal tensile strength, Young's modulus, elongation at break and antioxidant activity of the films can reach 12 MPa, 11 MPa, 133%, 81%, respectively. Minimum water vapor permeability was 3.1 × 10−12 gd−1m−1Pa−1. Notably, films incorporated with CNE (≥20%) had good DPPH free radical scavenging ability (>50%) when stored up to 6 days. Films with 25% CNE exhibited excellent antifungal activity against Trichoderma sp. and its inhibitory zone was 47 mm. Overall, the CSP films loaded with CNE (>15%) could be used as food packing materials with good antioxidant and antimicrobial activities.

Total phenolics content and antioxidant activity of extracts from dried water caltrop (Trapa Taiwanensis Nakai) hulls

This study was conducted to compare the total phenolics content and antioxidant activity of extracts from fresh (FS), freeze-dried (FD) and hot air-dried (HD) water caltrop hulls. The antioxidant properties, including 2,2-diphenyl-1-picrylhydrazyl (DPPH) free-radical scavenging activity, reducing power, and cupric ion chelating ability were evaluated along with alpha-tocopherol and butylated hydroxytoluene (BHT) in this study. The result showed that total phenolics content of methanolic extracts ranged from 5.21-8.59 g GAE/100 g, and the extracts of FS exhibited a substantial total phenolics content (8.59 g GAE/100 g) compared with other dried samples. It was found that the antioxidative effect of water caltrop hulls was strongly concentration dependent. The dose response study indicated that before reaching a threshold level, there was a positive correlation between DPPH free-radical scavenging ability and concentration of methanolic extracts. At the point where the scavenging ability of DPPH free-radical was 79.3%, the dose of the methanolic extracts was 0.2 mg/mL for FS, 1.5 mg/mL for HD, 1.8 mg/mL for FD, and 1.3 mg/mL for BHT. The chelating ability of three different water caltrop hull extracts reached a threshold level of only 28% at a dose of 2 mg/mL. The total phenolics contents were higher, but IC50 was lower in FS extracts than in other antioxidants. Compared with other treatments with antioxidants, the reducing power of FS extracts was found to be significantly more pronounced than that of HD and FD extracts, BHT and α-tocopherol, at dose ranges of 0-1.0 mg/mL. This finding demonstrated that FS extracts is comparable to BHT in terms of its antioxidant properties in food application.

Biological activities of in vitro liverwort Marchantia polymorpha L. extracts

To overcome the problems in liverwort collecting such as small size and easily mixed with other species in the wild, we have successfully cultivated Marchantia polymorpha L. under in vitro conditions in the previous study. The aim of this study is to evaluate the biological activities of this in vitro biomass as a confirmation of the sufficient protocol in cultivation this species. Cultured biomass was dried at a temperature of 45-50 oC to constant weight and ground into a fine powder. The coarse powder was extracted with organic solvents of increasing polarization including n-hexane, chloroform, ethyl acetate, and ethanol using the maceration technique. Four extracts were investigated antioxidant (iron reduction power, DPPH), antibacterial (agar diffusion), tyrosinase inhibitory activity, anti-proliferation on MCF-7 cells. Additionally, the presence of natural metabolite groups of the extracts was detected by using specific reagents. For antioxidant activity, ethyl acetate fraction extract had the highest iron reducing power and DPPH free radical scavenging ability with IC50 = 439.31 µg ml-1. All three n-hexane, chloroform, and ethyl acetate extracts possessed resistance to the bacterial strain tested. At a concentration of 2 mg ml-1, n-hexane and chloroform extracts had the highest percentage of tyrosinase inhibition (69.54 and 69.10%, respectively). The n-hexane extract is a potent extract that inhibits the proliferation of MCF-7 cells with the lowest IC50 of 38.15 µg ml-1. A preliminary chemical composition survey showed that the cultured biomass liverwort contains many bioactive compounds, particularly the compounds of range of non- and less-polarized fractions.

Effects of drying conditions in low-temperature microwave-assisted drying on bioactive compounds and antioxidant activity of dehydrated bitter melon (Momordica charantia L.).

Bitter melon (Momordica charantia L.) is a fruit that brings health benefits to consumers because the fruit is rich in bioactive compounds. In this work, a combination of low‐temperature convective drying and microwave radiation was used to dehydrate sliced bitter melon. One‐factor‐at‐a‐time design was performed to evaluate the influence of microwave power density (1.5, 3.0, 4.5 W/g), drying temperatures (20, 25, and 30°C), and air velocity (1.0, 1.2 and 1.4 m/s) on the change of moisture content, nutrient levels (vitamin C and total phenolics), and the antioxidant activities (DPPH and FRAP assays) of the bitter melon. The obtained results showed that all investigated factors affected the rate of moisture removal. Microwave power density output and air‐drying temperature strongly participated in the retention of nutrients. In this study, the drying process was driven by both heat and mass transfer processes, so the increase of air velocity prolonged the drying time causing more loss of nutrient levels and antioxidant activities. It was found that DPPH free radical scavenging ability directly correlated with total phenolic content, but the ferric‐reducing antioxidant power was related to the presence of reductants including phenolic compounds, vitamin C, and other phytochemicals in bitter melons. This work determined that microwave power density and the air‐drying temperature are the main two factors that should be used for further investigations.

Synthesis and characterization of new 4H-chromene-3-carboxylates ensuring potent elastase inhibition activity along with their molecular docking and chemoinformatics properties.

A new series of 4H-chromene-3-carboxylate derivatives were synthesized using multicomponent reaction of salicylaldehyde, ethyl acetoacetate and dimedone in ethanol with K3PO4 as a catalyst at 80°C. The structures of all newly synthesized compounds were confirmed by spectral techniques viz. IR, 1H NMR, 13C NMR, and LCMS analysis. The newly synthesized compounds 4a to 4j were screened against elastase enzyme. Interestingly, all these compounds found to be potent elastase inhibitors with much lower IC50 value. The compound 4b was found to be most potent elastase inhibitor (IC50=0.41±0.01µM) amongst the synthesized series against standard Oleanolic Acid (IC50 value=13.45±0.0µM). The Kinetics mechanism for compound 4b was analyzed by Lineweaver-Burk plots which revealed that compound inhibited elastase competitively by forming an enzyme-inhibitor complex. Along with this, all the synthesized compounds (4a - 4j) exhibits excellent DPPH free radical scavenging ability. The inhibition constant Ki for compound 4b was found to be 0.6µM. The computational study was comprehensible with the experimental results with good docking energy values (Kcal/mol). Therefore, these molecules can be considered as promising medicinal scaffolds for the treatment of skin-related maladies.

The contribution ratio of various characteristic tea compounds in antioxidant capacity by DPPH assay.

Tea is a worldwide health beneficial beverage for its antioxidant ability. 1,1-diphenyl-2-picryl-hydrazyl (DPPH) assay is a common method to measure the antioxidant capacity of tea compounds, yet the contribution ratio of various characteristic tea compounds is still unclear. high-performance liquid chromatography (HPLC) was used to examine the content of polyphenol compounds in 24 tea samples from four tea categories (green tea, white tea, oolong tea, and black tea). Based on the results of DPPH and HPLC, contribution ratio of each tea compound was analyzed by the Pearson correlation analysis and the partial least squares regression (PLSR). The Pearson correlation analysis showed that the order of correlation between the area of 13 peaks and the antioxidant ability of tea samples was x8>x6>x3>x13>x10>x7>x2>x5>x11>x9>x4>x12>x1; the regression equation fit by PLSR was Y=47.258-0.760x1+0.287x2-1.484x3-0.569x4+0.674x5+2.257x6+1.698x7+1.389x8-0.188x9+0.467x10+0.297x11+1.314x12+0.963x13. We identified nine common peaks by reference standard substances: the x3 was gallic acid (GA), x4 was theobromine, x5 was catechuic acid (CA), x6 was epigallocatechin (EGC), x8 was epigallocatechin gallate (EGCG), x9 was caffeine, x10 was epicatechin (EC), x12 was epicatechin gallate (ECG), and x13 was gallocatechin gallate (GCG). Based on the study of spectrum-effect correlation, we obtain a better understanding of the antioxidant activity of complex tea polyphenols component. PRACTICAL APPLICATIONS: Identify the contribution of specific chemical compound to antioxidant activity by the coefficients in PLSR equation and provide a deeper insight into the joint effect of multiple ingredients of tea. Further, we can infer the DPPH free radical scavenging ability of a new kind of tea by the PLSR equation without chemical detection.

Effects of Selenium on Differentiation and Antioxidant Activity of Sclerotium of Penicillium thomii Q1 Strain.

Selenium is an essential trace element, which has certain antioxidant properties. Na2SeO3 is toxic, and its use is limited. SeMet, as an organic selenium, is less toxic than Na2SeO3. In this experiment, different concentrations of Na2SeO3 and SeMet were added to MEA and PDA media to observe the effect of selenium on the sclerotium differentiation of Q1 strain, and the contents of carotenoids, ascorbic acid, and total phenol and their reducing power, DPPH free radical scavenging ability, ferrous ion chelating ability, and superoxide anion scavenging ability were determined. Meanwhile, the orthogonal design was used to optimize the selenium enrichment culture conditions of Q1. The results showed that the addition of selenium in the PDA medium was not conducive to the differentiation of Q1 strain. The addition of inorganic and organic selenium in the MEA medium at different concentrations resulted in the accumulation of carotenoids, ascorbic acid, phenols, and selenium in the sclerotia of Q1 strain, and the contents of carotenoids, ascorbic acids, and selenium in the sclerotia of Q1 strain were increased to different degrees, but it cannot increase the content of total phenol. In addition, when the concentration of Na2SeO3 and SeMet in the medium was 10 μg/mL, the reducing power of the extract was improved. The experimental results can provide a new research idea for the utilization and development of Penicillium sclerotium and selenium.

Gas chromatography-mass spectrometry (GM-MS) analysis and biological activities of the aerial part of Cleome amblyocarpa Barr. and Murb.

Cleome amblyocarpa Barr. and Murb is a medicinal plant widespread in North Africa and widely used in Tunisia to treat diabetes and colic. The non-volatile (polyphenols, flavonoids, tannins, and flavonols) and volatile compounds (GC-MS) of C. amblyocarpa leaves and stems have been studied. The antioxidant, antimicrobial, analgesic, and cytotoxic activities of hydroalcoholic extracts of C. amblyocarpa leaves and stems were also investigated. The major volatile components were β-caryophyllene (46.9%), eugenol (25.6%), ethyl 3-methylpentanoate (16.2%), 7-epi-silphiperfol-5-ene (11.0%), and α-copaene (7.0%). The antioxidant activity has been evaluated using various in vitro assays, such as DPPH free radical scavenging activity, iron-chelating capability, and ability to inhibit lipid peroxidation (TBARS). The antibacterial and antifungal effectiveness of leaves and stems parts of Cleome amblyocarpa were investigated by means of the disc diffusion and microdilution techniques. The in vitro cytotoxicity of the hydroalcoholic extract of C. amblyocarpa on A549 and H1299 lung adenocarcinoma cells was determined using the crystal violet assay. The acute toxicity of the extracts on Swiss albino mice at the doses of 3000, 1500, and 500mg/kg body weight was evaluated. The analgesic effect of leaves and stems extract was also determined by means of the acetic acid induced writhing test. The results indicated that the leaves have higher phenols, and flavonoids contents and potential antioxidant, antimicrobial, and anticancer activities in comparison to stem. In addition, the aerial part of C. amblyocarpa did not cause signs of toxicity or death in animals at doses up to 3000mg/kg and have a significant analgesic activity.

Comparison of different extraction techniques and optimization of the microwave-assisted extraction of saponins from Aralia elata (Miq.) Seem fruits and rachises

The total saponins from Aralia elata (Miq.) Seem fruits and rachises were isolated by microwave-assisted extraction (MAE), ultrasonic extraction, heat reflux extraction, and soxhlet extraction. These techniques were compared from four perspectives: extraction kinetics, saponin yield, disintegration to the raw materials, and antioxidant activity. MAE had the highest extraction efficiency, shortest time, and greatest disintegration to the raw materials. The extracts obtained with MAE had the highest antioxidant activities, as the DPPH free radical scavenging abilities of the fruit and rachis extracts were 70.86 ± 1.33 and 50.85 ± 1.68 mg VC g−1md, respectively. The MAE parameters were optimized by the response surface methodology. The optimum conditions (92% and 91% ethanol, solid-to-liquid ratios of 1:30 and 1:22, microwave powers of 530 W and 400 W, microwave times of 40 s and 54 s) provided extraction yields of 2.98 ± 0.037 mg g−1 and 0.94 ± 0.026 mg g−1 from the fruits and rachises, respectively.

Bioactive compounds from Syzygium malaccense leaves: optimization of the extraction process, biological and chemical characterization

Syzygium malaccense belongs to the family Myrtaceae and it is popularly recognised as ‘jambo’ in Brazil. It is poorly studied regarding the bioactive compounds of fruits and leaves. This study aimed at optimizing the extraction and characterization of bioactives compounds from S. malaccense leaves. Extraction was optimized using a 23 full factorial design to evaluate the effect of ethanol concentration, time and temperature on polyphenols and antioxidants contents. Analyses of phenolic compounds content (Folin-Ciocalteau and HPLC-DAD), in vitro antioxidant capacities (DPPH, ABTS and FRAP), antimicrobial activity against bacteria and yeasts of ethanolic extract was carried out in optimal conditions of extraction. The optimized extraction condition was 45 min., 80°C and 40:60 (v v-1) ethanol:water. The extract showed high total phenolic content (0.074 mg GAE kg-1), DPPH (0.666 μmol TE kg-1) and ABTS (0.853 μmol TE kg-1) free radical scavenging ability and appreciable ferric reducing power (1.267 μmol Fe2+ kg-1). HPLC methodology allowed the identification of four bioactive compounds: gallic acid (0.00036 mg kg-1), catechin (0.00021 mg kg-1), rutin (0.00027 mg kg-1) and quercetin (0.00003 mg kg-1). The extract showed inhibitory activity against S. aureus (1 µg L-1); S. bongori (8 µg L-1), C. albicans and C. tropicalis (2 µg L-1). It also showed microbicidal potential against S. aureus; C. albicans and C. tropicalis.

Hydro-Ethanolic Extract of Mentha pulegium Exhibit Anthelmintic and Antioxidant Proprieties In Vitro and In Vivo.

During recent decades, the emergence of chemoresistance among synthetic anthelmintic drugs has increased the interest in screening novel natural anthelmintic compounds derived from plants. The current study is aimed to determine the chemical profile, anthelmintic and antioxidant properties of Mentha pulegium hydro-ethanolic extract. Two tests were used to assess the in vitro anthelmintic activity of the hydro-ethanolic extract of M. pulegium against Haemonchus contortus; egg hatch assay (EHA) and adult worm motility (AWM) assay. M. pulegium extracts at the doses of 500, 1000, 2000 and 4000 mg/kg were evaluated in vivo in mice infected with Heligmosomoides polygyrus. The anthelmintic efficacy was monitored using faecal egg count reduction (FECR) and total worm count reduction (TWCR). The antioxidant activity of M. pulegium extract was evaluated by testing the total antioxidant capacity and the DPPH free radical-scavenging ability. Chromatographic characterization of M. pulegium composition using RP-HPLC revealed the presence of phenolic acids such as syringic acid, ferulic acid and the presence of flavonoid compounds, such as isorhamnetin-3-O-glucoside and kaempferol-3-O-rutinoside. We observed 91.58% inhibition in the EHA at 8 mg/mL after 48 h of incubation (IC50=1.82 mg/mL). In the AWM assay, M. pulegium extract achieved 65.2% inhibition at 8 mg/mL after 8 h. The highest dose (4000 mg/kg) showed a significant nematicidal effect 7 days post-treatment by inducing 60.39% FECR and 71.6% TWCR. We also report strong in vivo antioxidant capacity of the extract, as revealed by a significant increase of the enzymatic activities of catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GPx) enzymes in mice infected with H. polygyrus. Together, the results in this paper suggest that M. pulegium possesses anthelmintic properties and could be a potential source of novel compounds for the control of helminth parasites as well as its associated oxidative damage.

Changes of Active Constituents and Antioxidant Properties of Four Kinds of Tea during Gastrointestinal Digestion in Vitro

In order to recognize the changes of active ingredients in tea in vivo,the four kinds of tea of Zijuan,Zhonghuang Yihao,Baiye Yihao and Fuding Dabai were selected. The changes of polyphenols,flavonoids,proanthocyanidins and antioxidant activity were determined through simulated gastrointestinal digestion in vitro. The results showed that the content of polyphenols and total flavonoids in Fuding Dabai tea was the highest,while the content of proanthocyanidins in Zijuan tea was the highest. DPPH free radical scavenging ability of Fuding Dabai tea was the highest,while the Zijuan ABTS free radical scavenging ability was the best. Compared the gastric digestion stage(0~2 h)with the intestinal digestion stage(2~4 h),it was found that the polyphenol content of the four kinds of tea decreased significantly during the gastric digestion stage,and the proanthocyanidins content did not decrease significantly. The content of flavonoids in Fuding Dabai,Zhonghuang Yihao and Baiye Yihao kinds of tea showed a downtrend,while Zijuan tea increased. In the intestinal digestion stage,the content of polyphenols and flavonoids in Fuding Dabai,Zijuan,Zhonghuang Yihao and Baiye Yihao increased,while the proanthocyanidin content decreased. The scavenging ability of DPPH free radical and ABTS free radical of the four kinds of tea in simulated gastrointestinal digestion decreased gradually.

Analysis of antioxidation activity for the small molecular biomass extracted from the waste of resources

The waste of peanut press cake from oil mill was powdered and used as the feedstock to extract the protein and the extract solution was further hydrolysed by using an enzyme mixture of alcalase and flavourzyme. The peanut protein was become the smaller molecules after enzymatic hydrolysis and the antioxidation activities were analysed by using experimental design. The response surface methodology was applied to analyse the parameters and the interaction between parameters of the enzymatic hydrolysis process for the variation of antioxidation activities of the small molecular protein. On the basis of the experimental results, the optimum responses of antioxidation activities were obtained as the DPPH free radical scavenging ability of 76.85%, reducing power (absorbance value) of 0.1 Abs, and Ferrous ion (Fe2+) chelating ability of 17.19% under the operating parameters in solid-liquid ratio of 1:10, enzyme concentration of 10%, and hydrolysis time of 8 hr.