Antioxidant Activity Of Fruit Extracts Research Articles

Comparative Analysis of Polyphenols in Lycium barbarum Fruits Using UPLC-IM-QTOF-MS.

Variety, geographical origin, and harvest season are important factors affecting the accumulation of polyphenols in Lycium barbarum. In this study, the effects of these factors on the polyphenolic components of this species were analyzed using ultra-performance liquid chromatography ion mobility quadrupole time-of-flight mass spectrometry. Moreover, the in vitro antioxidant activities of fruit extracts from this species were evaluated. The total polyphenolic contents of L. barbarum fruits from Jinghe County in Xinjiang and Zhongning County in Ningxia were 5.52-11.72 and 7.06-9.37 mg (gallic acid equivalent)/g dry weight, while the total flavonoid contents of L. barbarum fruits from these regions were 12.52-30.29 and 12.67-20.77 mg (rutin equivalent)/g dry weight, respectively. Overall, 39 types of polyphenols were identified in the fruit extracts, including 26 flavonoids, 10 phenolic acids, and three tannins. Of these, 11 polyphenols were quantitatively analyzed, which revealed rutin to be the most dominant polyphenolic component in fruits from Jinghe and Zhongning. There were significant differences (p < 0.05) in the polyphenolic contents and antioxidant activities of L. barbarum fruit extracts, depending on the geographical origin, variety, and harvest season. The antioxidant activity of this species was found to be significantly positively correlated with the polyphenolic contents. This study provided scientific guidance for comprehensive applications of polyphenols from different varieties of L. barbarum from separate geographical origins.

Opuntia ficus indica (L.) fruit extract alleviates oxidative stress through activation of dual oxidases and Keap1/Nrf2 signaling cascades in high-fat-diet associated atherosclerosis rats.

Atherosclerosis is a metabolic disorder characterized by chronic inflammation associated with progressive thickening and hardening of the large to medium-sized arteries due to plaque formation. The study aims to evaluate the antioxidative, anti-inflammatory, and hypolipidemic efficacy of Opuntia ficus-indica (OFI) fruit extract against the high-fat-diet associated atherosclerotic rat model. In-vitro qualitative and quantitative phytochemical screening of OFI fruit extract revealed the significant presence of total phenolic content and total flavonoid contents. In-vitro antioxidant activity of fruit extract was determined through 2,2-diphenyl-1-picrylhydrazyl and FRAP assays that have shown their protective efficacy against the overproduction of reactive oxygen species. Results revealed that the level of total oxidant stress was significantly (P<0.05) reduced and down expression levels of dual oxidases (Duox, Duoxa-1, and Duox-2) in all the treatment groups (I, II, III) as compared with positive control were observed. The total antioxidant capacity was significantly (P<0.05) increased in all treatment groups in comparison with the positive control group and higher expression level of the Nrf-2 signaling pathway (Nfe-212, NFR-1, and Keap-1) was observed in all the treatment groups compared with the positive control group. Histopathological examination of the aorta showed that high-fat diet markedly increased endothelial lining and thickness of tunica media and adventitia, with irregular media segments having wavy laminae, and a significant increase in entropy of fibers disposition was observed. Conclusively, OFI fruit extract has shown promising protective, anti-oxidative, and anti-inflammatory efficacy through the restoration of normal parenchyma in high-fat dieting-associated oxidative stress and endothelial inflammation.

Phenolic Content and Antioxidant Activity in Fruit of the Genus Rosa L.

Throughout history, people of different cultures have acknowledged the relationship between food properties and health. The pseudo-fruits of different Rosa species contain high levels of vitamin C and other beneficial biological active agents such as phenolics, and others. The purpose of the research was to determine the variability of the phenolic compound profiles in the fruit of different species of Rosa L. and to evaluate the antioxidant activity of fruit extracts in vitro. The total contents of phenolics, flavonoids, procyanidins, and hydroxycinnamic acid derivatives were performed using the spectrophotometric method. Qualitative and quantitative analysis of individual phenolics in rosehip samples was carried out by applying the HPLC method. The largest amounts of phenolic compounds 26.49 ± 1.32 mg GRE/g were found in rosehip samples of the Rosa pisocarpa species. (+)-Catechin was the predominant phenolic compound in rosehip fruit samples, and the highest content 522.48 ± 26.12 µg/g was found in rosehip samples of the Rosa subcanina species. A strong correlation was found between the total amount of phenolic compounds determined in rosehip extracts and the radical scavenging and reducing the activity of their extracts in vitro (r = 0.759 and 0.761, accordingly, p < 0.001).

Gene Expression of Antioxidant Metabolic Enzymes in Grape Extracts

Fruit can use its structural characteristics to stabilize the excess electrons of free radicals and prevent cell aging, which is the main source of antioxidants supplementation. In the current study, the expression of antioxidant metabolic genes was evaluated in fruit extract. Seventy mice were divided into one control group and six experimental groups. Six experimental groups were fed 0.1g of grape extract daily for 3, 7, 10, 14, 21, 24 and 30 days, respectively. The antioxidant activity of fruit extract was tested by antioxidant metabolic enzyme gene expression in the liver and kidney of different experimental groups. The results showed that grape extract could effectively enhance SOD activity, LPL relative expression and FAS relative expression in mice liver tissue; grape extract could effectively increase SOD relative expression, TrxR2 relative expression and CAT relative expression in mice kidney tissue; grape extract could effectively reduce MDA activity in mice liver tissue, and increase and decrease the extent of MDA activity and the duration of feeding in mice. The proportion of fruit extracts showed that fruit extracts could effectively improve the antioxidant performance of the body.

&lt;i&gt;In-vitro&lt;/i&gt; antioxidant, anti-inflammatory and cytotoxic activity of &lt;i&gt;Cucumis melo L. &lt;/i&gt;of ethanolic extract

Introduction and Aim: Cucumis melo L. commonly known as wild melon (in English) belongs to the family Cucurbitaceae and well distributed in rural areas. Cucumis melo L. is a annual climbing or perennial herb, distributed almost throughout India and neighbouring countries. Nowadays food wastes are a major concern. On the other hand, the demand for natural valuable compounds to human health is increasing. These by-products contain phytochemical compounds with great nutritional and functional potentials. The fruits of this plant possess the abortifacient property and have antitussive, antioxidant, digestive, cytotoxic and anti-inflammatory properties.&#x0D; &#x0D; Materials and Methods: The ethanolic extract was used to determine the antioxidant scavenging activity using DPPH method, protein denaturation for anti inflammatory studies, as well as in vitro cytotoxic activity by brine shrimp lethal assay (BSLA).&#x0D; &#x0D; Results: The results obtained indicated highest antioxidant activity as compared to DPPH methods. The protein denaturation test showed the ethanolic extracts of Cucumis melo L. had effective anti-inflammatory activity. Extracts of Cucumis melo L. also registered potential cytotoxic activities by BSLA. This study provides the basis for further investigation of Cucumis melo L. for potential identification of novel bioactive compounds with therapeutic properties.&#x0D; &#x0D; Conclusion: The presence of phytoconstituents such as flavonoids, terpenoids, alkaloids, may indeed assist to the antioxidant activity of fruit extract. That this next thing that must be done will be to conduct in vivo experiments and discern the histopathological mechanism.

Evaluation of anti-arthritic and anti-inflammatory activities of Martynia annua L. Ethanolic extract

BackgroundArthritis is a disorder of change in joint architecture and ligament degeneration. Rheumatoid arthritis is an autoimmune disorder in which body’s immune system targets own cells and degrade them. Martynia annua L. has been used in Indian traditional therapies for the treatment of epilepsy, many types of inflammations, respiratory infection, sore throat and wound. The objective of the present study was to determine anti-inflammatory and anti-arthritic activities of M. annua ethanolic fruit extract.MethodsThe extraction was performed using ethanol as a solvent followed by phytochemical investigation of M. annua ethanolic fruit extract. Antioxidant and anti-hyaluronidase enzyme inhibition activities was performed for the fruit extract. In vivo anti-inflammatory of fruit extract was performed on Calotropis procera latex (CPL) induced paw edema in rats using ibuprofen as standard. Inflammation was observed at 0, 1, 2, 4 and 6 h. In vivo anti-arthritic of fruit extract was performed on Complete Freund’s adjuvant (CFA) induced arthritis in rats. Arthritis was observed at 0, 7, 14 and 21 day. X-Ray study was also performed for inflammatory and arthritic paw of rats.ResultsThe qualitative phytochemical screening of fruit extract showed presence of flavonoids, terpenoids, saponins, tannins, steroids, glycosides, proteins, carbohydrates, amino acids and polysaccharides. The antioxidant activity of fruit extract was 49.1 as compared to standard 45.73 at 100 μl dose. The anti-hyaluronidase enzyme inhibition activity of fruit extract was 84.60 as compared to standard 94.21 at 100 μl dose.ConclusionIt is evident from the study that Martynia annua L. extract possess both antioxidant and hyalurinodase inhibition activity at dose dependent manner as well as anti-arthritic and anti-inflammatory potential.

STUDY ON CHANGES IN CHEMICAL COMPOSITIONS AND BIOACTIVE COMPOUNDS IN POUTERIA CAMPECCHIANA FRUIT DURING STORAGE

ABSTRACT - QMFS 2019 Pouteria campecchiana, a fruit cultivated in many provinces of the Mekong Delta, is typically eaten fresh and has many benefits to human health. Therefore, quality control during storage of this fruit is very important for fresh consumption and food processing. This study was conducted to investigate the effects of postharvest maturity on the quality of the fruit stored at room temperature, mainly on its chemical composition and bioactive compounds content. The results showed that storage time greatly affected amounts of carotenoids, tannin, phenolic and flavonoids: Highest content of carotenoids, polyphenols, flavonoids were obtained at day 10th of storage while tannin content gradually declined. The greatest antioxidant activity of fruit extracts was also obtained after 10 days storage. It was recommended that highest nutritional value of Pouteria campecchiana can be achieved from 8 to 10 days after harvest.

EVALUATION OF THE ANTIOXIDANT ACTIVITY OF FRUIT EXTRACTS OF INDIGENOUS MEDICINAL PLANT, ZIZYPHUS XYLOPYRUS (RETZ.) WILLD

Aim: This study aims to investigate the antioxidant activity of fruit extracts of an indigenous medicinal plant, Zizyphus xylopyrus (Retz.) Willd. Materials and Methods: The coarsely powdered fruit of Z. xylopyrus Willd. was successfully extracted first with petroleum ether and chloroform, followed by ethyl acetate and at last ethanol. The total flavonoids content (TFC), total phenolic content (TPC), and total tannin content (TTC) were estimated using quercetin and tannic acid equivalents as standard. The antioxidant activity of different extracts was determined by different standard in vitro methods including. Results: Among all extracts, ethyl acetate extract (ZXEAE) possessed potent antioxidant activity, namely hydroxyl radical (OH°) scavenging assay (IC50 128.1 ± 0.63 μg/mL), 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical (DPPH°) scavenging assay (IC50 101.2 ± 1.75 μg/mL), nitric oxide radical (NOo) scavenging assay (IC50 122.5 ± 2.04 μg/mL), superoxide radical (O2¯) scavenging activity assay (IC50 64.1 ± 1.24 μg/mL), and inhibition of lipid peroxidation (98.6 ± 2.05 μg/mL). Study results suggested that antioxidant activity of ZXEAE might be due to presence of polyphenols, namely TFC (31.23 ± 0.39 quercetin equivalent [QE] mg/g extract), TPC (198.14 ± 0.69 gallic acid equivalent [GAE] mg/g extract), and TTC (18.38 ± 1.79 GAE mg/g extract). Conclusion: The present study demonstrated the presence of flavonoids in Z. xylopyrus fruits showing marked antioxidant activity, which can be used for establishing the hepatoprotective potential of Z. xylopyrus

Comparison on Bactericidal and Cytotoxic Effect of Silver Nanoparticles Synthesized by Different Methods

Biologically synthesized silver nanoparticle are biocompatible for medical applications. The present work is aimed to synthesize silver nanoparticle using the fruit pulp of Tamarindusindica and to evaluate its antibacterial and anticancer activity against lung cancercell lines. Antibacterial activity was assessed by well diffusion method. Cytotoxicity was evaluated using MTT assay. GC-MS of fruit pulp extract showed the presence of levoglucosenone, n-hexadecanoic acid, 9,12-octadecadienoic acid etc. Antioxidant activity of the fruit pulp was determined by DPPH assay, hydrogen peroxide scavenging assay and lipid peroxidation. The size of biologically synthesized silver nanoparticle varied from 50 nm to 76 nm. It was 59 nm to 98 nm for chemically synthesized silver nanoparticle. Biologically synthesized silver nanoparticle showed 26 mm inhibition zone against E. coli and chemically synthesized silver nanoparticle showed 20 mm. Antioxidant activity of fruit extract by DPPH showed 84 % reduction. The IC 50 of biologically synthesized silver nanoparticle against lung cancer cell lines was 48 µg/ml. It was 95 µg/ml for chemically synthesized silver nanoparticle. The increased activity of biologically synthesized silver nanoparticle was due to its smaller size, stability and the bioactive compounds capping the silver nanoparticle extracted from the fruit extract.

Phenolic acids and flavonoids profiles of extracts from edible wild fruits and their antioxidant properties

ABSTRACTIn this study, the total phenolic, total flavonoids, phenolic compounds, the mineral content, and antioxidant activity of fruit extracts of seven wild species (Crataegus monogyna Jacq., Prunus spinosa L., Rosa canina L., Hippophaë rhamnoides L., Rubus fruticosus L., Prunus padus, Cornus mas L.) were investigated. The results indicated significant differences (p < 0.05) in the total phenolics and total flavonoids content, between the seven analyzed species. These ranged from 184.69 to 727.29 mg GAE/100 g FW and 17.27 to –165.55 mg QE/100 g FW, respectively. The antioxidant activity found in fruits was not directly affected by the total phenolic content (TPC). This activity was linked to a larger extent to the type of individual phenolic compounds and to a lesser extent to the TPC, because fruits with higher TPC have not always presented the highest values of antioxidant activity. HPLC analysis of methanolic extract showed the presence of phenolic acids (i.e. gallic, vanillic, chlorogenic, caffeic, syringic, p-coumaric, ferulic, sinapic, salycilic, elagic, and trans-cinnamic) and flavonoids (i.e. catechin, epicatechin, rutin, myricetin, and quercetin). Significant differences (p < 0.05) were observed in each individual mineral between fruits from wild flora. The fruits tissues of wild species turned out to be a good source of calcium (Ca), magnesium (Mg), sodium (Na), iron (Fe), manganese (Mn), copper (Cu), chromium (Cr), zinc (Zn), and boron (B). The results demonstrated that wild species possessed great potential for food production as sources of bioactive compounds such as phenolic compounds and minerals, for food supplements or functional foods.

Effect of Lagenaria siceraria fruit extract (Bottle gourd) on hepatotoxicity induced by antitubercular drugs in albino rats

Background: Anti TB drug induced hepatotoxicity has higher incidence in Indian population [11.5%] than western population [4.5%]. Antitubercular drug induced hepatotoxicity is mediated through oxidative and free radical damage to hepatocytes. Lagenaria siceraria [Bottle Gourd] is reported to have antioxidant and hepatoprotective activity. Hence in the present study we tested hepatoprotective and antioxidant activity of fruit extract of L. Siceraria in anti tubercular drug induced hepatotoxicity. Methods: We administered antitubercular drugs alone and in combination with fruit extract of Lagenaria siceraria (EELS 100mg/kg and EELS 200mg/kg) in healthy albino rats by oral route for 15 days. On 16th day blood collection for biochemical analysis is done by cardiac puncture. Biochemical markers used are serum transaminases (SGPT/SGOT), serum alkaline phosphatase [ALP], total bilirubin, total protein, superoxide dismutase [SOD] and malondialdehyde [MDA]. Liver is dissected for histopathological examinations. Results: Groups that received EELS [100 mg/kg &amp; 200 mg/kg], in combination with anti tubercular drugs, showed significant reduction [p value &lt;0.001] in biochemical parameters for hepatotoxicity [SGOT, SGPT, ALP, Total bilirubin, Total protein] in comparison with group that received anti tubercular drugs alone. Combined treatment of EELS [100 mg/kg &amp; 200 mg/kg] &amp; Anti tubercular drugs showed significant reduction in oxidative stress [SOD &amp; MDA, p&lt;0.001] as compared to anti tubercular drug alone. Histopathological examination of liver showed grade I &amp; grade 0 changes in combination group while grade IV changes in group receiving anti tubercular drugs alone. Conclusion: Ethanolic extract of Lagenaria siceraria fruit possesses significant hepatoprotective and antioxidant activity in antitubercular drugs induced hepatotoxicity.

Phytochemical characterization of several hawthorn (Crataegus spp.) species sampled from the Eastern Mediterranean region of Turkey

Background:We evaluated the total phenolic content, antioxidant capacity as well as antioxidant activity of five Crataegus species (A1, A2, Y1, Y2, Y4 accessions of Crataegus aronia var. aronia; B2, B3, B5, B6, B7, B9, Y5 accessions of C. aronia var. dentata; B10 accession of C. aronia var. minuta; Y3 accession of Crataegus orientalis var. orientalis and A3 accession of Crataegus monogyna subsp. azarella).Materials and Methods:Antioxidant activity and total phenolic content of fruits were determined by β-carotene bleaching and Folin–Ciocalteu assays. Antioxidant capacity was determined by using 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay.Results:C. monogyna subsp. azarella had the highest total phenol, antioxidant activity and antioxidant capacity of 55.2 mg gallic acid equivalents (GAE)/g dry weight (DW), 81.9% and 31.2%, respectively. C. aronia var. aronia was found to have the lowest total phenolic content (35.7 mg GAE/g DW). The antioxidant activities of fruit extracts increased in the order of C. orientalis var. orientalis < C. aronia var. minuta < C. aronia var. dentata < C. aronia var. aronia < C. monogyna subsp. azarella according to β-carotene/linoleic acid assay. In recent years, C. aronia var. dentata has gained importance as a commercial species in this region. B3 and B7 accessions had fruit weight more than 14 g, and considerable total phenol content, antioxidant activity and antioxidant capacity.Conclusion:This investigation shows the potential value of hawthorn fruit species as a good source of natural antioxidants and that consumption of hawthorn fruit or its products may contribute substantial amounts of antioxidants to the diet.

Evaluation of Free-Radical Scavenging and Antioxidant Activity of Fruit Extracts of Three Endemic Rhamnus Species in in vitro

The antioxidant properties of Rhamnus petiolaris Boiss., R. rhodopeus Velen. subsp. anatolicus (Grub.) Browicz & Ziel., and R. thymifolius Bornm., three endemic species occurring at altitudes of 1000 – 1200 meters on volcanic rock around Afyonkarahisar was evaluated. Antiradical activity of Rhamnus petiolaris Boiss., R. thymifolius Bornm. and R. rhodopeus Velen. subsp. anatolicus (Grub.) Browicz & Ziel was found 0.47, 0.56, and 0.68 respectively. Chelation of the samples via Fe2+ ranged from 38.78 % to 54.79 %. R. rhodopeus Velen. subsp. anatolicus (Grub.) Browicz & Ziel showed the highest chelation via Fe2+, which was 54.79 %. Another method to determine the antioxidant activity of the samples was elimination of H O , which appeared to be 36.12 % in Rhamnus petiolaris Boiss., 53.89 % in R. thymifolius Bornm., and 68.732 %2 in R. rhodopeus Velen. subsp. anatolicus (Grub.) Browicz & Ziel. Also for this test, R. rhodopeus Velen. subsp. anatolicus (Grub.) Browicz & Ziel exhibited the highest antioxidant activity.

Antigenotoxic and Antioxidant Activities of Fruit Extracts from (Tunisian) Pistacia Lentiscus

Genotoxic and antigenotoxic activities against direct acting mutagen nifuroxazide, and indirect acting genotoxin aflatoxine B1 (AFB1) of extracts prepared from fruits of Pistacia lentiscus, were studied using the SOS chromotest with Escherichia coli PQ 37 as a tester organism. It was found that different extracts showed no genotoxicity when tested with E. coli PQ 37 strain either with or without microsomal extract. On the other hand, our results showed that ethyl acetate fraction and total oligomers flavonoids (TOF) extract obtained from P. lentiscus significantly decreased the genotoxicicity induced by AFB1 (10 μg/assay) and nifuroxazide (20 μg/assay). In addition to antigenotoxic activity, these extracts showed an important free radical scavenging activity towards the 2,2-diphenyl-2-picrylhydrazyl (DPPH) free radical and an important antioxidant activity using xanthine/xanthine oxidase system.

Polyphenolic profile and antioxidant activity of five apple cultivars grown under organic and conventional agricultural practices

SummaryThe polyphenols and total antioxidant activities of five apple cultivars, grown by organic and conventional agricultural methods in neighbouring farms, were determined and compared. Total polyphenols in the whole fruit and in the peel were determined by the Folin‐Ciocalteu method, and the total antioxidant activity was determined by three established methods, diphenyl picrylhydrazyl (DPPH), azinobis (3‐ethylbenzthiazoline‐6‐sulfonic acid) (ABTS) and ferric reducing/antioxidant power (FRAP). Polyphenolic content for the whole fruit was in the range of 80–196 and for the peel 165–400 (mg Gallic Acid Equivalent (GAE)/100 g fresh weight) for both types of agricultural practices. Antioxidant activities of fruit extracts were also relatively similar and well correlated to their polyphenolic content. High‐performance liquid chromatography (HPLC) analysis of the most important polyphenolics (chlorogenic acid, catechin, epicatechin, procyanidin B1 and B2, cyaniding 3‐galactoside, phloridzin, quercetin 3‐galactoside and quercetin 3‐arabinoside) also showed that concentrations do not differentiate significantly between the organic and conventional apples. Statistical significance of differences in antioxidant activities among the same cultivars was relatively small (flesh + peel or peel only) for both types of apples. These results indicate that organic apples do not present higher antioxidant or nutritional value compared with conventionally grown ones, as far as polyphenolic content and total antioxidant activities are concerned.

A COMPARATIVE STUDY OF SHELF-LIFE PERFORMANCE OF TWO KIWIFRUIT CULTIVARS IN RELATION TO MATURITY AND NUTRITIONAL QUALITY

‘Hayward’ is the predominant kiwifruit (Actinidia deliciosa C.F. Liang and A.R. Ferguson var. deliciosa) cultivar in international trade whereas the ‘Tsachilidi’ is a new variety developed and released recently in Greece with good attributes and possibilities for a high commercial-scale production. Therefore, the objective of this work was to study the shelf-life and antioxidants performance of ‘Hayward’ and ‘Tsachilidi’ kiwifruits. Commercially-mature ‘Hayward’ and ‘Tsachilidi’ kiwifruits were obtained from orchards in the region of Imathia (North Greece). Then, the fruits were stored at 0°C for 6 months. After removal from cold storage, the fruit was kept at 20°C and 65-70% relative humidity for 1, 3 and 5 days. Changes in the kinetics of fruit firmness, soluble solids concentration, titration, CO2 and ethylene production were assessed. Shelf-life did not affect soluble solids contents and titratable acidity in both cultivars. The softening process was remarkable only in ‘Tsachilidi’ after 5 days of shelf-life. During shelf-life the ethylene production was increased whereas the CO2 production was decreased in both cultivars. However, there were no significant differences in CO2 production rates among the cultivars tested. The phenolic and ascorbic acid content, and the total antioxidant activity of fruit extracts were higher in ‘Tsachilidi’ than ‘Hayward’ during shelf-life.

Avaliação da atividade antioxidante utilizando sistema beta-caroteno/ácido linoléico e método de seqüestro de radicais DPPH•

SUMMARY EVALUATION OF THE ANTIOxIDANT ACTIVITy USING THE B-CAROTENE/LINOLEIC ACID SySTEM AND THE DPPH SCAVENGING METHOD. The antioxidant activity of fruit extracts (acerola, acai, black-berry and strawberry) and pure compounds has been analysed by two methods: β-carotene/linoleic acid and DPPH•(2,2-diphenyl-1-picrylhydrazyl) radical scavenging assay. First, those methodologies were adapted to be performed in microplates, in order to reduce the sample and reagent amounts, to increase the number of simultaneous analyses and to automate absorbance lectures. The results showed that the antioxidant activity of the fruit extracts was in accordance with those of pure ascorbic acid and phenolic compounds, in the two systems. The acerola extract, due to its high vitamin C content, acted as pro-oxidant, but acai, black-berry and strawberry extracts acted as antioxidants in β-carotene/

Investigations on the antioxidant activity of fruit and vegetable aqueous extracts on superoxide radical anion using chemiluminescence techniques

A sensitive and simple method for measuring antioxidant activity was developed, based on antioxidant-dependant quenching of the chemiluminescence (CL) generated from 9-benzylacridine and potassium superoxide. This method was used to evaluate the antioxidant activity of fruit and vegetable aqueous extracts as well as of some pure phenolic compounds contained in fruits and vegetables. Coumaric, chlorogenic, caffeic, vanillic and ascorbic acids as well as (±)catechin, and 2-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid (trolox) were employed as antioxidants. It was found that the antioxidant activity of all fruit extracts is almost one order of magnitude higher than that of vegetables. Among the fruits, grapefruits show the highest antioxidant activity and pears the lowest. From the pure phenolic antioxidants, caffeic acid has the highest antioxidant activity (AA). The calculated antioxidant activities of fruit and vegetable extracts produced by the CL method are compared with other methods such as the ORAC, TEAC or DPPH method.

Hypoglycemic and hypolipidemic effects and antioxidant activity of fruit extracts from Lycium barbarum

The hypoglycemic and hypolipidemic effects of Lycium barbarum fruit water decoction, crude polysaccharide extracts (crude LBP), and purified polysaccharide fractions (LBP-X) in alloxan-induced diabetic or hyperlipidemic rabbits were investigated through designed sequential trials and by measuring blood glucose and serum lipid parameters. Total antioxidant capacity was also assessed using trolox equivalent antioxidant capacity (TEAC) and oxygen radical absorbance capacity (ORAC) assay. It was found that the three Lycium barbarum fruit extracts/fractions could significantly reduce blood glucose levels and serum total cholesterol (TC) and triglyceride (TG) concentrations and at same time markedly increase high density lipoprotein cholesterol (HDL-c) levels after 10 days treatment in tested rabbits, indicating that there were substantial hypoglycemic and hypolipidemic effects. Hypoglycemic effect of LBP-X was more significant than those of water decoction and crude LBP, but its hypolipidemic effect seemed to be weaker. Total antioxidant capacity assay showed that all three Lycium barbarum extracts/fractions possessed antioxidant activity. However, water and methanolc fruit extracts and crude polysaccharide extracts exhibited stronger antioxidant activity than purified polysaccharide fractions because crude extracts were identified to be rich in antioxidants (e.g., carotenoids, riboflavin, ascorbic acid, thiamine, nicotinic acid). Lycium barbarum polysaccharides (glycocojugates), containing several monosaccharides and 17 amino acids, were major bioactive constituents of hypoglycemic effect. Both polysaccharides and vitamin antioxidants from Lycium barbarum fruits were possible active principles of hypolipidemic effect.