POLYPHENOL lá và CỌNG r SATIVUS

Plant Foods Hum Nutr 2010 65:8–17DOI 10.1007/s11130-009-0148-6 SyedSultanBeevi&MangamooriLakshmiNarasu& Published online: 14 January 2010 # Springer Science+Business Media, LLC 2010 Abst

Plant Foods Hum Nutr (2010) 65:8–17

DOI 10.1007/s11130-009-0148-6

SyedSultanBeevi&MangamooriLakshmiNarasu&

Published online: 14 January 2010

# Springer Science+Business Media, LLC 2010

AbstractAerial parts (leaves and stem) of Raphanus

sativus,whichareusuallydiscardedwerefoundtopossess

potent antioxidant and radical scavenging activity, as

acetoneextractsofR.sativusleaveshadtotalpolyphenolic

comparabletothetraditionalrichsourcessuchasgreentea

thepresenceofcatechin,protocatechuicacid,syringicacid,

vanillic acid, ferulic acid, sinapic acid, o-coumaric acid,

myricetin, and quercetin in leaves and stem Among the

differentextractionsolvents,methanolicextractofleavesand

stem showed potent reductive capacity, significantly

inhibited linoleic acid peroxidation and displayed metal

chelating activity Further, they scavenged free radicals

effectivelywithIC50(halfmaximalinhibitoryconcentration)

superoxideradical,67and197µg/mlforhydrogenperoxide,

and56and62µg/mlfornitricoxide,respectively.Leaves

showed most potent antioxidant and radical scavenging

thehighpolyphenoliccontent.LeavesandstemofR.sativus,

oftenunder-utilizedpartofthisvegetable,thuspossessed

regardedasapotentialsourceofnaturalantioxidantsand

couldbeeffectivelyemployedasaningredientinhealthorin

functionalfood

activity.Radicalscavengingactivity Introduction

rela-tionship between intake of fruits and vegetables and

braindysfunction, etc [1], which may be attributed to theirantioxidantproperty.Theseresearcheshave

augmentedtheconsumer awareness of the potential

health benefits ofnaturally occurring phytochemicals

from plants Freeradicalssuchasreactiveoxygenspecies (ROS)andreactivenitrogen species (RNS) have been

widely implicated asmediatorsinthedevelopmentof thesechronicdiseases[2].Amongthedietaryconstituents, polyphenolicsappeartoaplay a significant role as

antioxidants in the protectiveeffectofplantderived foods[3].Phenolicshavebecomethefocusofcurrent nutritionalandtherapeuticinterest.Theantioxidantactivity

ofthedietaryphenolicsisconsideredto be superior to

that of the essential vitamins and isascribedtoitshigh redoxpotentialwhichallowsthemtointerrupt free

radical mediated reactions by donatinghydrogenfrom

none ofthesideeffectsassociatedwithsynthetic

S S Beevi:M L Narasu (*):B B Gowda

Centre for Biotechnology, Institute of Science and Technology,

Jawaharlal Nehru Technological University,

Kukatpally, Hyderabad – 500 085,

Andhra Pradesh, India

e-mail: mangamoori@jntuh.ac.in

e-mail: mangamoori@rediffmail.com

antioxidants[5]

traditionalIndiancuisine.Themostpopularpartfor con-sumptionisthenapiformtaproot,althoughtheentireplant

isedibleandtheaerialpartcanbeusedasaleafvegetable

purposes.RootsareusedinIndiantraditionalmedicineto

supportahealthyliverandtopromotedigestion[6,7].Itis

stimulantandappetizerinherbalmedicine[6,7]

Pharma-cologicalstudieshaveshownthatR.sativusrootextracts

ratsfedwithfatrichdiet[8]andpreventedtheformation

ofcalculusintheurinarytractinexperimentalanimals[9]

proliferationandinducecancercellstoundergoapoptosis

[10] Root, stem and leaf of R sativus showed broad

spectrum of antibacterial activity against food-borne

pathogens and drug resistant strains [11,12].Recently,

R.sativusisgainingrenewedinterestasaningredientfor

presenceofglucosinolatesandtheirdegradationproducts,

prop-ertiesofR.sativushavealsobeenattributedtophenolic

compounds

Previousstudieshavecharacterizedtheradical

scaveng-ingactivityofcrudemethanolicextractsofseveralculinary

plantsincludingR.sativussprouts,whichdisplayedoneof

andfoundtocontainsinapicacidestersandflavonoidsas

main phenolic components [13] However, information

ofleavesandstemofR.sativusisalmostlacking.Hence,

antioxidantactivityofleaves andstemofR.sativus,often

under-utilizedpartofthisvegetablewouldsubstantiate

theirvalue in the human nutrition as well as food

leaves and stem of R sativus by solvents of increasing

polarity(hexane,chloroform,ethylacetate,acetone,

meth-anol and water) and screened by HPLC-DAD The

antioxidantactivitiesoftheseextractswereevaluatedby

power,inhibitionoflinoleicacidperoxidation,andmetal

chelating activity The radical scavenging potential was

species(nitricoxide)

Allchemicalsandreagentsusedintheexperimentswereof

analytical grade and obtained from Sigma-Aldrich (St

used for extraction were of HPLC grade and were

PlantMaterialsandPreparationofExtracts

stem, washed thoroughlywith distilledwater andfreeze

leavesandstemwereextractedthreetimeswithsolventsof varyingpolaritysuchasmethanol,acetone,ethylacetate,

(Heidolph-Rotacool, Germany) at 40 °C Dried residues were

activities.WaterextractofR.sativuswaspreparedas aboveby soaking dried powder into distilled waterand

filters(Millipore,Bedford,MA)andwerestoredat−80°C untiluse

Total polyphenolics content of R sativus extracts was

Kimetal.[14].Thetotalconcentrationof polyphenolic

Polyphenolics in the different parts of R sativus were

was carried out using a Luna C18 column (250 mm× 4.6mmi.d.;particlesize,5µm)withaC18guardcolumn

sodiumacetate(solventA)andacetonitrile(solventB).A

10 Plant Foods Hum Nutr (2010) 65:8–17

postrunatinitialconditionsforequilibrationofcolumn

detector was set at 280 nm for catechin, protocatechuic

acid, vanillic acid, syringic acid, and o-coumaric acid;

myricetinandquercetin

Thestandardpolyphenolicsselectedforthe

identificationofcompoundsinR.sativuswerecatechin,

protocatechuicacid,vanillicacid,syringicacid,

o-coumaricacid,sinapicacid,ferulicacid,myricetin,and

quercetin.PolyphenolicsintheR.sativusextractswere

quantifiedusinglinearregressionequationsderivedfrom

authenticstandards.Thepolypheno-lic compounds were

identified on the basis of theircomparison of their

retention time and spectral matchingwiththatof

authenticstandards,andalsobyco-elutiontofurther

AntioxidantActivityofR.sativus

[15]andisbasedonthereductionofTPTZ-Fe3+ complex

toTPTZ-Fe2+ forminthepresenceofantioxidants.The

antioxidant capacity was expressed as µM FeSO4/ of

dried extract Quercetin and butylated hydroxyl toluene

of the extracts was evaluated according to the method

described by Yen and Chen [16] and expressed as

absorbanceat700nm.ThechelatingcapacityofR.sativus

extracts on Fe2+ ions was determined according to the

method of Dinis et al [17], wherein the Fe2+ chelating

expressed as percent chelation of Fe2+ ions relative to

negativecontrol without R sativus extracts or standards

extractstoinhibittheformationofperoxidesinlinoleic

acidsystem was determined according to the

thiocyanatemethod [19] The method is based on the

capacity ofperoxidestocatalyzetheoxidationofFe2+

toFe3+.TheFe3+producedislinkedtothethiocyanate

spectrophotometricallyat500nm[20]

DPPHradical-scavengingactivityofR.sativusextractsand

previ-ouslydescribed[21].Thecapacityof extractstoscavenge

the lipid-soluble 2, 2-diphenyl-1-picrylhydrazyl (DPPH)

radical,whichresultsinthebleachingofthepurplecolor

radicals was determined according to the method of Nishikimietal.[22].Superoxideradicalsweregenerated

in PMS-NADH system by oxidation of NADH and analyzed by NBTreduction at 560 nm The method of Sinha [23] originally designed for the estimation of the

onthecouplingofexcessH2O2withdichromateinacetic acid to produce a green color which was measured at

620 nm The method of Rai et al [24] based on the spontaneous generation of nitric oxide (NO·) from the

assesstheNOscavengingabilityofR.sativusextractsand

of extractsandstandardwasexpressedasIC50,whichwas

inhibi-tion(Y-axis)againstconcentration(X-axis)oftheextracts andstandards

StatisticalAnalysis

least significant difference test using Statistical Analysis System(SAS,ver.9.1).Graphing,curvefitting,andIC50

EffectofSolventontheYieldofTotalSolubleSolids

The yield of soluble substances, expressed as mg/g dry weight of leaves and stem of R sativus and the total extractable polyphenolics, expressed as catechin

yieldandthepolyphenolicscontent.Thehighestyieldwas

withwater,followedbythatobtainedwithmethanol,ethyl

polyphenolics varied among different extracting solvents

totalpolyphenolicsinwaterandethylacetateextractwasin the range 34–37 mg/g, which was markedly less as compared to that of methanol and acetone extracts

Table Extraction yields, total polyphenolics content, ferric reducing activity (FRAP assay), and percentage inhibition of linoleic acid peroxidation of R sativus leaves and stem extracts a

Extraction solvent Parts of R sativus Yield (mg/g dry weight) Total phenolics b FRAP (mM FeSO 4 /g) Percent inhibition of linoleic

acid peroxidation

a Values are expressed as means ± SD (n =3)

b Expressed as mg catechin/g dry extract

were found in the following order; methanol extract

chloro-formextract(16.78mg/g),andhexaneextract(1.92mg/g)

The colorimetric method for the determination of

compoundscaninterfere[25]anditsreactivityisdifferent

fordifferentpolyphenolics[26].Although,thismethodis

generally used and preferred as is straightforward to

obtain comparative results with other plant materials

accountedintheliterature.Fromourresult,itwasapparent

extractionsolvents andtheir polarity.Withpolarsolvents,

wecouldbeabletoextractsignificantamountsofphenolics

fromR.sativus.Previousstudiesindicatedasimilartrend

extractedintothepolarsolvents[27].Thetotal

polypheno-liccontent reportedfor blackkaleleaves(1366ng/g)[28]

andgingerrhizomes(0.05–0.98mg/g)[29]appearedtobe

muchlesserthanthatofleavesandstemofR.sativus.In

addition, the polyphenolic content of leaves was almost

comparable to the phenolic content of traditionally rich

106mg/g),respectively[30].Ourfindingsthussuggested

thepotentialofleavesandstemofR.sativustobe

exploitedasasourceofnutritionalpolyphenolics

ofR.sativus

provides more precise information of individual

in the leaves and stem of R sativus These included catechin,protocatechuicacid,vanillicacid,syringicacid, ferulicacid,sinapicacid,o-coumaricacid,myricetin,and quercetin(Table2).RepresentativeHPLCprofilesrecorded

meth-anolicextractofleavesandstemarepresentedasFig.1a–c

thatleafextractscontainedmoreamountsofpolyphenolics than that of the stem extract Catechin (4.88 mg/g and

waterextractofleavesandstem.Vanillicacid,ferulicacid, sinapic acid, and o-coumaric acid were the predominant phenolicacidsinthemethanolicextractofleavesandstem Catechinandvanillicacidweredetectedasmajorphenolics

inacetoneextract.Although,flavonolssuchasmyricetinand quercetinwerenotdetectedinanyoftheseextracts.While myricetin(6.41mg/g)wasthemainflavonolidentifiedinthe ethylacetateextractofleaves.Chloroformextract

Quercetin,andnoneofthepolyphenolics(standardsused foranalysis)weredetectedinthehexaneextractsofleaves

12 Plant Foods Hum Nutr (2010) 65:8–17 Table 2 Polyphenolics content of leaves and stem of R sativus (mg/g dry weight) a

Extraction

solvent

Parts of

R sativus

Catechin Proto-catechuic

acid

Syringic acid

Vanillic acid

Ferulic acid

Sinapic acid

o-Coumaric acid

Myricetin Quercetin

Water Leaves 4.88±0.13 ND b ND ND ND 0.62±0.008 1.05±0.005 ND ND

Stem 1.13±0.034 ND 0.70±0.006 0.69±0.004 ND ND 0.57±0.006 ND ND Methanol Leaves 0.36±0.005 ND ND 4.13±0.34 1.29±0.046 3.21±0.19 2.13±0.049 ND ND

Stem 0.22±0.002 ND ND 1.76±0.25 0.32±0.003 1.32±0.092 1.64±0.061 ND ND Acetone Leaves 2.11±0.097 ND ND 1.96±0.096 ND ND 0.19±0.001 ND ND

Stem 1.03±0.083 ND ND 1.64±0.083 ND ND 0.86±0.007 ND ND Ethyl

acetate

Leaves ND ND 0.53±0.003 1.39±0.072 ND 1.09±0.057 ND 6.41±0.23 0.49±0.000 Stem ND 0.08±0.000 0.19±0.000 ND ND 0.75±0.005 0.36±0.003 0.41±0.002 ND

a Values are means ± SD (n =3)

b Not detected

sativussprouts[13].However,wedetectedanassortment

ofphenolics in leaves and stem of R sativus

Catechin,vanillic acid, sinapicacid, ferulic acid,

o-coumaric acid,andmyricetinseemedtobethemost

thisstudywasthat thecatechin content of the water

extract (4.88 mg/g) andacetoneextract(2.11mg/g)of

tea(1.3mg/g)andblacktea

(1.7 mg/g) [30] Sinapic acid, the most predominant

phenolic acid in most cruciferous vegetables was to be

higherthanthosereportedforcauliflower[31]andblack

cabbage[28].Similarly,ferulicacidcontentofmethanolic

extract(1.29mg/g)ofleaveswassignificantlyhigherthan

thatpresentinbittercumin(0.376mg/g)[32].Likewise,

myricetin content of ethyl acetate extract of leaves

presentintheredgrapesskin(44µg/g)[33]

AntioxidantPropertiesofR.sativus

theantioxidantactivitysuchashydrogendonation,

termi-nationoffreeradicalmediatedchainreaction,preventionof

hydrogen abstraction, chelation of catalytic ions, and

elimination of peroxides [34] Antioxidant activity is a

dependent system and the characteristic of a particular

systemcaninfluencetheoutcomeoftheanalysis.Hence,a

singleassaywouldnotberepresentativeoftheantioxidant

potential of plant extracts In the present study, we

employed different models of antioxidant assays which

could provide a more reliable approach to assess the

antioxidantandradicalscavengingpotentialofleavesand

stemofR.sativus

The ferric reducing ability (FRAP) of the leaves and stem of R sativus is shown in Table 1 The water,

ionsefficientlyandhadreducingactivityintherangeof

antiox-idant BHT (1.28 mM/g) Ethyl acetate and chloroform extractsshowedmoderatereducingactivityintherangeof

stemhadnegligiblereducingactivity.Alltheextractswere lesseffectivewhencomparedwiththereducingactivityof

standard antioxidants such as quercetin and BHT at a concentrationof250µg/mlispresentedinFig.2.Leaves and stem extracts showed variable reducing power with leaves displaying the higher reducing power than stem extracts The reducing ability of methanolic extracts of

otherextractsandpresentedareducingpowerof0.698and 0.497,respectively.However,hexaneextractsofleavesand

revealed the most potent reducing power of 0.974 and 0.928,respectively,whichweredistinctlyhigherthanthat

ofanyoftheR.sativusextracts

concom-itantwiththereducingpoweroftheplantextract.Results from this study suggested that the distinct reducing abilityof leaves andstem ofR.sativusappearedtobe theresult oftheirantioxidantactivity.Hence,itcanbe

stem couldactasreductonesbydonatingelectronstofree

reactions[34]

600

500

400

300

200

100

0

tionof250µg/ml.ThemetalchelatingcapacityofR

extractswere the highest, followed by water, acetone,

and ethylacetateextracts.Chloroformandhexane extracts

of leavesand stem displayed least activity and there

quercetin,andBHT exhibited 99.23%, 60.54% and

71.36% of metalchelating activity respectively, which

were significantlyhigherthanthatoftheR.sativus extracts

Transition metal ions gain utmost significance in the biologicalsystemsduetotheirabilitytogeneratereactive freeradicals.TheycaninitiateFentontypereactionwith

140

120

100

80

60

40

20

0

withsuperoxideradicals.Theseactiveoxygenfreeradicals

perox-idationwhichisimplicatedinvariouschronicdiseases[35]

ionsintheFentontypereactionandthuswouldprotectthe

dependent processes [36] Even though, none of the R sativusextractsshowedmetalchelatingabilityas signifi-cant as EDTA, they could still chelate iron at higher concentrations.Thisresultisnotsurprisingasnon-phenolic compounds are supposed to be the better chelators of

c)

200

150

100

50

0 10 20 30 40 50 60 min

Antioxidativeactivityoftheleavesandstemextractsin thelinoleicacidsystem(250µg/ml)isshowninFig.4aand

b.Inthe absence of extracts, linoleic acid was auto-oxidized,whichwasfollowedbyarapidincreaseof peroxidesstartedatthe2nddayoftesting,reached

probablyduetolackoflinoleicacidinthereactionsystem Alltheextractsdisplayedstrongtomoderateantioxidant activityinthelinoleicacidsystemandsignificantly delayedtheperoxidationoflinoleicacidataconcentration

differentextractstested,methanolicextractsweremost effectiveintheinhibitionoflinoleicacidperoxidation (Table1).Thepercentageinhibitionofoxidationinlinoleic Fig 1 Representative HPLC chromatograms recorded at 280 nm a)

Mixture of standard polyphenolics; b) Methanolic extract of stem; c)

Methanolic extract of leaves Peaks: (1) catechin; (2) protocatechuic

acid; (3) syringic acid; (4) vanillic acid; (5) ferulic acid; (6) sinapic

acid; (7) o-coumaric acid; (8) myricetin; (9) quercetin

LeavesandstemofR.sativuswereabletochelate

ferrousion in concentration dependent manner

However, theestimatedIC50 valuewasveryhigh(more

showsthemetalchelatingactivityofleavesandstemofR

sativusataconcentrationof

andstematthe6thdayofanalysiswasfoundtobe81.99% and 76.55%, respectively, which were comparable to

thereferenceantioxidants,suchasquercetin(81.64%)and BHT

(82.98%).Water,acetone,andethylacetateextracts showedinhibitory activities in the range of 63–80%

The otherextractsofR.sativuswerelesseffectivein comparisonwithquercetin andBHT, but showed inhibitoryactivity attherangeof54–67%

Lipid peroxidation is a free radical mediated chain reaction that can inactivate cellular components and are purportedly associated with various chronic disorders including carcinogenesis [35] It is a known fact that transitionmetalionsmayeitherinitiatelipidperoxidation throughgenerationofhydroxylradicalsorpropagatechain

14 Plant Foods Hum Nutr (2010) 65:8–17 Fig 2 Reducing power of R.

sativus leaves and stem extracts,

quercetin and BHT at a

concen-tration of 250 µg/ml Results are

means ± standard deviation of

three parallel measurements

0.8

0.7

0.6

0.5

0.4

0.3

0.2

0.1

0 Quercetin BHT Water Methanol Acetone Ethyl acetate Chloroform Hexane

Hence, reduction or removal of metal ions through

bywhichinitiationoflipidperoxidationcanbeinhibited.In

thisstudy,R.sativusextractssignificantlyinhibitedperoxyl

radical induced oxidation of linoleic acid However,

responsiblefortheobservedactivityasR.sativusextracts

werefoundtopossesslowmetalchelatingactivity.Hence,

weassumedthatpolyphenolicspresentintheextractscould

scavenge peroxyl radicals by donating hydrogen atom

before it can react with linoleic acid and thus inhibited

lipidperoxidation

Basic information on the efficacy of compounds in R sativusextractstoquenchfreeradicalscanbededuced

concentration-dependent scavenging of DPPH radicals, with leaves presenting the strongest effects Among the different extracts,methanolicextractshowedthestrongest effect(IC50at31µg/mlforleaves and42µg/mlforstem), followed by water, acetone, and ethyl acetate extracts Chloroform and hexane extracts displayed the weakest

radicalscavengingactivitywiththestandardantioxidants

Fig 3 Metal chelating ability of

R sativus leaves and stem

extracts (1.0 mg/ml), EDTA,

quercetin and BHT

(250 µg/ml) Results are

means ± SD (n =3)

120

100

80

60

40

20

0 EDTA Quercetin BHT Water Methanol Acetone Ethyl

acetate Chloroform Hexane

2.5

2

1.5

1

0.5

0

Control Water Methan ol Acetone

Ethyl acetate Chloroform Hexane

b

2.5

2

1.5

1

0.5

0

Control Water Methan ol Acetone

Ethyl acetate Chloroform Hexane

Fig 4 a Antioxidative activity of R sativus leaves extracts in the linoleic acid system (250 µg/ml) Results are the means of duplicate analysis.

b Antioxidative activity of R sativus stem extracts in the linoleic acid system (250 µg/ml) Results are the means of duplicate analysis

showed that the most potent R sativus extracts had

scavengingabilityhigherthanBHT(IC50 at493µg/ml),

butlowerthanthequercetin(IC50 at11µg/ml)

superoxide radicals, H2O2, and nitric oxide radicals are

presentedinTable3.ExtractsfromleavesandstemofR

sativusdisplayedconcentrationdependentprotective

activ-ityagainstthereactivespecies,ofwhich,leaveswerethe

mosteffectivematerial.Methanolicextractsofleaves(IC50

attherangeof23–56µg/ml)andstem(IC50attherangeof

Water,acetoneandethylacetateextractsshowedstrongto moderateactivitywithIC50 intherangeof46–682µg/ml

signifi-cant scavenging activity against nitric oxide, moderate activity againsthydrogen peroxide and the least activity against superoxide radicals Hexane extracts showed the leastactivityagainstanyofthereactivespeciesgenerated

in vitro When radical scavenging activity of R sativus extracts compared to the IC50 values calculated for the

Table 3 Scavenging ability of leaves and stem of R sativus and standard antioxidants on DPPH·, superoxide radical (O 2 ·), hydrogen peroxide (H 2 O 2 ), and nitric oxide (NO·) as determined by their IC 50 , expressed as mg/g dry weight a

Extraction solvent Parts of R sativus IC 50 (expressed as mg/ml)

Standard antioxidants Quercetin 0.011±0.002 0.010±0.000 0.034±0.001 0.036±0.002

a All data were average (± SD) of three replicates

16 Plant Foods Hum Nutr (2010) 65:8–17

could generate potentially reactive oxygen and nitrogen

species, such as singlet oxygen, hydroxyl radicals, and

peroxynitrite.Thesereactivespecies arebelievedtoactas

inducers of cellular injury through initiation of lipid

strandbreaks.R.sativusleavesandstemhave

demonstratedtheir ability to scavenge free radicals

such as DPPH·,superoxide anion, hydrogen peroxide

and nitric oxideeffectivelybyactingaschain-breaking

antioxidants.Anti-oxidantandradicalscavenging

propertiesofphenolicacidsandflavonoidsdetectedin

invariousmodelsystems[38].Several studies have

reported the relationship betweenpolyphenolics

structure and antioxidant activity, demon-stratingthat

ringseffectivelycontributetothechain-breaking

antioxidantactivitybystabilizingtheradicalforminelectron

delocation [39] Among the polyphenolics found in the

leaves and stem, many have hydroxyl groups in their

freeradical-inducedchainreactions,andthuscould

contrib-utesignificantlytotheantioxidantactivityofR.sativus

A comparison between the DPPH radical scavenging

andstemofR.sativusweremorepotentintermsofradical

scavengingactivitywherebytheirIC50werecomparatively

muchlowerthantheseculinaryspices[29,40],thusfurther

demonstrating the effectiveness of R sativus leaves and

stemasnaturalantioxidants.Polyphenolicsofcruciferous

vegetables are reported to have preventive and curative

properties against various chronic diseases However,

polyphenolics seemed to be more concentrated in the

thanintheiredibleparts.HollmanandArts[41]

demon-stratedhigherflavonoidcontentsintheleavesof

cauliflow-er than in their edible parts, where trace amounts of

flavonoids were identified Ayaz et al [28] likewise

propertiesintheleavesandseedofblackcabbage

Conclusions

Ourstudieshaveshownforthefirsttimethepresenceofan

array of polyphenolics such as catechin, protecatechuic

acid,syringicacid,vanillicacid,ferulicacid,sinapicacid,

o-coumaricacid,myricetin,andquercetinintheleavesand

stem of R sativus Among the different solvents used,

methanol extract possessed significant amounts of

poly-phenolics and showed potent antioxidant and radical

methanol>acetone>ethyl acetate>water>chloroform>hex-ane Leaves showed significant antioxidant and radical

(leavesandstem)ofR.sativus,oftenunder-utilizedpartof thisvegetableshouldthusberegardedasapotentialsource

ofnaturalantioxidant,andhavepotentialtobedeveloped

asaningredientinhealthorfunctionalfood.Further ex-tensive scientific study into this rather abundant natural resourceiswarranted

Acknowledgement This study was supported by a funding under the Technology Education Quality Improvement Program (TEQIP) by World Bank to Centre for Biotechnology, Institute of Science and Technology, Jawaharlal Nehru Technological University, Hyderabad, India The first author acknowledges the financial support from CSIR

in the form of a Senior Research Fellowship.

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