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218 S. D. KULKARNI ET AL.
Copyright © 2006 John Wiley & Sons, Ltd. Phytother. Res. 20, 218–227 (2006)
Copyright © 2006 John Wiley & Sons, Ltd.
PHYTOTHERAPY RESEARCH
Phytother. Res. 20, 218–227 (2006)
Published online in Wiley InterScience (www.interscience.wiley.com) DOI: 10.1002/ptr.1838
Evaluation of the Antioxidant Activity
of Wheatgrass (Triticum aestivum L.)
as a Function of Growth under Different
Conditions
Sunil D. Kulkarni1, Jai. C. Tilak2, R. Acharya3, Nilima S. Rajurkar1, T. P. A. Devasagayam2
and A. V. R. Reddy3*
1Department of Chemistry, University of Pune, Pune 411 007, India
2Radiation Biology and Health Sciences Division, Bhabha Atomic Research Centre, Mumbai 400 085, India
3Radiochemistry Division, Bhabha Atomic Research Centre, Mumbai 400 085, India
The antioxidant activity of wheatgrass, which is consumed as a dietary supplement, was estimated at different
levels. The methods employed include FRAP (ferric reducing antioxidant power), ABTS (2,2′′
′′
′-azobis-3-
ethylbenzthiazoline-6-sulfonic acid) and DPPH (1,1′′
′′
′-diphenyl-2-picrylhydrazyl) assays. Aqueous and ethanol
extracts of wheatgrass grown under different conditions over a period of 6, 7, 8, 10 and 15 days were used.
Lipid peroxidation and oxygen radical absorbance capacity (ORAC) were determined and utilized to check
the potency of a few selected extracts. Different conditions used for growth were (1) tap water, (2) tap water
with nutrients, (3) soil and tap water, and (4) soil with nutrients. For comparison, a commercially available
wheatgrass tablet was analysed. To explain the reasons behind the observed differences, the total phenolic and
flavonoid contents of the extracts were measured. These contents increased with growth under all the condi-
tions. The ethanol extracts were found to have a higher phenolic and flavonoid content than the aqueous
extracts. The highest FRAP values occurred on day 15 of growth under condition 4, the values being 0.463 and
0.573 mmol of ascorbic acid and Trolox equivalents/100 g fresh wheatgrass for aqueous and ethanol extracts,
respectively. In the aqueous extracts no specific trend was observed with the DPPH assay for the different
conditions nor for the growth period. In the case of ethanol extracts, however, it increased with the growth
period and the wheatgrass grown in condition 4 was found to be the most effective. These extracts were also
found to inhibit significantly ascorbate-Fe2++
++
+ induced lipid peroxidation in rat liver mitochondria. The ORAC
values of aqueous and ethanol extracts of day 10 with condition 4 were found to be 39.9 and 48.2, respectively,
being higher than those reported for many natural extracts or vegetables. Copyright © 2006 John Wiley &
Sons, Ltd.
Keywords: wheatgrass; antioxidant potential; growth period; free radicals; lipid peroxidation; ORAC values.
Received 26 May 2005
Accepted 21 November 2005
INTRODUCTION
Reactive oxygen species (ROS) are generated continu-
ously in living organisms due to various metabolic proc-
esses as well as to exposure to various physico-chemical
agents. At normal physiological concentrations they are
required for cellular activities. But, at higher concen-
trations, they can be toxic leading to oxidative stress.
They can damage major cellular components and have
been implicated in various human diseases such as
different forms of cancers, neurogenerative disorders,
cardiovascular diseases (CVDs) and diabetes mellitus
as well as in the process of aging (Harman, 1981; Droge,
2002). Antioxidants are capable of neutralizing the
deleterious effects of free radicals. In a normal healthy
state endogenous antioxidants act as the body’s effec-
tive defense system against free radicals. However,
in the diseased state, additional antioxidants from the
diet and other sources such as medicinal plants are
required for effective recovery.
In the past two decades, research in nutrition and
food science has focused on plant products with poten-
tial antioxidant activities. Such products are also rich
in fibre, have no cholesterol and contain antioxidants
such as carotenoids and flavonoids. The compounds,
which are mainly responsible for the antioxidant effect,
are a class of phenolic compounds including flavonoids
and their derivatives besides carotenoids and toco-
pherols (Nocole et al., 1996; Sergio et al., 1999). The
search is on for plant products with high antioxidant
activities.
Germination/sprouting causes extensive changes in
the seeds. During this stage, the synthesis of useful
compounds such as vitamins and phenolics occurs.
Wheat (Triticum aestivum L.) germinated over a
period of 6–10 days is generally called ‘wheatgrass’.
In recent years, in some European countries, USA
and India, wheatgrass, in the form of a ready-made
juice or tablet is being consumed as a ‘health food’.
* Correspondence to: Dr A. V. R. Reddy, Radiochemistry Division,
Bhabha Atomic Research Centre, Mumbai 400 085, India.
E-mail: avreddy@magnum.barc.ernet.in
Contract/grant sponsor: Board of Research in Nuclear Sciences (BRNS),
Department of Atomic Energy (DAE), India under Memorandum of
Understanding (MoU) between Bhabha Atomic Research Centre
(BARC)-University of Pune.
ANTIOXIDANT ACTIVITY OF WHEATGRASS 219
Copyright © 2006 John Wiley & Sons, Ltd. Phytother. Res. 20, 218–227 (2006)
Aqueous and ethanol extracts of wheatgrass, prepared
from fresh wheatgrass collected at various stages of
growth, were studied. Samples were collected on 6, 7,
8, 10 and 15 days after germination. The aqueous
extracts were similar to those that people consume as
a herbal drink. In order to estimate the total content
of the bioactive organic compounds ethanol extracts
were prepared as most of the organic compounds are
soluble in ethanol. The antioxidant activities of both
aqueous and ethanol extracts were determined. The
antioxidant activities of wheatgrass were estimated
using different assays for its ability to inhibit radical
formation (ABTS assay), radical scavenging (DPPH
assay), ferric reducing antioxidant power (FRAP) and
capacity to inhibit lipid peroxidation in rat liver mito-
chondria. The levels of total phenolic and flavonoids
present were also estimated. In addition, the oxygen
radical absorbance capacity (ORAC) of the wheatgrass
extracts was checked.
Preparation of wheatgrass extracts. The seeds of wheat
(Triticum aestivum L. C.V. Pbn-51) were procured and
washed with tap water followed by distilled water. The
seeds were soaked in distilled water for 8 h and trans-
ferred to the containers. The wheat plants were grown
in (1) tap water, (2) tap water with nutrients, (3) soil
and tap water, and (4) soil with nutrient solution, and
termed conditions 1, 2, 3 and 4, respectively. In condi-
tions 1 and 2, the plants were grown in cylinders with
perforated plastic tops (h = 5 cm and diameter = 20 cm)
called ‘wheat-sprout makers’. A total of 100 seeds were
placed in each sprout maker. 200 mL of water (pH =
6.3 ± 0.3, Na 4.3 µg/mL, K 3.6 µg/mL, Ca 8.1 µg/mL,
Mg 3.8 µg/mL Zn, Mn, Cu < 0.1 µg/mL) was added
everyday in condition 1. The same quantity of water
along with nutrients was added to the sprout maker in
condition 2. The composition of the nutrient solution
was 2 mm KNO3, 2 mm Ca (NO3) 2, 1 mm MgSO4, 1 mm
KH2PO4, 25 µm H3BO3, 2 µm MnCl2, 2 µm ZnSO4, 0.5 µm
CuSO4 and 0.5 µm Na2MoO4 (Hoagland and Arnon,
1950). In conditions 3 and 4, the seeds were sowed in
the trays of dimension 15 × 35 cm2, containing 7 kg of
soil (pH = 7.5 ± 0.4, K 8157 ± 269 µg/g, Na 2415 ± 25,
Ca 8657 ± 256, Mg 9845 ± 647, Mn 3520 ± 35, Cu 3.5 ±
0.7, Fe 6190 ± 512, Zn 840 ± 25 µg/g). The trays with
soil were provided with sufficient tap water/nutrient
solution regularly and were placed in a room where
normal airflow and sunlight were available. During the
growth of the plants, samples were collected on days 6,
7, 8, 10 and 15.
The samples collected on different days were washed,
wiped and cut into small pieces. They were homo-
genized with a clean pestle and mortar using either
distilled water or ethanol (10% w/v). The extracts were
centrifuged at 15 000 rpm for 20 min at 4 °C and the
supernatants were stored at −20 °C until further use.
The extracts were diluted to 1% and 5% as required.
The aqueous and ethanol extracts of commercial
tablets were prepared in a similar fashion and identi-
fied as A1 and E1, respectively.
Ferric reducing antioxidant power of wheatgrass ex-
tracts. The ferric complex reducing ability of the ex-
tracts was measured by the FRAP assay (Pulido et al.,
2000). The calibration curve was plotted with absorb-
ance at 595 nm versus concentration of FeSO4 in the
It is presumed that the wheatgrass is a rich source
of vitamins, antioxidants and minerals in a bioavail-
able form. Wheatgrass contains vitamins C and E,
β
-carotene, ferulic acid and vanillic acid whose concen-
tration increases with the germination period and
reaches a maximum on day 7 of growth (Hanninen
et al., 1999). There are reports on the antimutagenic
effect of wheatgrass extracts towards benzo(a)pyrene
induced mutagenicity. Wheatgrass extracts also pos-
sess superoxide scavenging and ferric reducing power
(Peryt et al., 1992). Their ability to inhibit oxidative
DNA damage was also demonstrated (Falcioni et al.,
2002). Chlorophyll, one of the active components in
the wheatgrass extract, was found to be responsible
for inhibiting the metabolic activation of carcinogens
(Lai et al., 1978; Lai, 1979). Recently, some clinical
trials have indicated the healing properties of wheat-
grass in different diseases. It was shown to reduce
transfusion requirements in patients suffering from
thalassaemia (Marwaha et al., 2004). It is effective for
the treatment of distal ulcerative colitis besides having
a significant ability to reduce the overall disease act-
ivity index and the severity of rectal bleeding (Ben-
Arye et al., 2002).
The observed beneficial effects can possibly be
ascribed to the antioxidant properties. Although there
are some preliminary studies (Peryt et al., 1992),
the antioxidant activity of wheatgrass, at various levels
of protection, has not been studied in detail. It is also
not known at what period of growth wheatgrass has
the maximum antioxidant potential. The effect of
different germination conditions used for the cultiva-
tion of wheatgrass such as nutrients and soil has not
been studied. To fulfil these lacunae, the present study
assessed the antioxidant potential of wheatgrass,
at different levels of action, during its germination
period under different growth conditions. The poss-
ible factors responsible for the differences observed,
in terms of the chemical composition, were also
examined.
MATERIALS AND METHODS
Materials. Ascorbic acid, aluminium chloride, 2,2′-
azobis-3-ethylbenzthiazoline-6-sulfonic acid (ABTS)
diammonium salt,
β
-phycoerythrin, 1,1′-diphenyl-2-
picrylhydrazyl (DPPH), ethylene diamine tetra acetic
acid (EDTA), ferric chloride, Folin-Ciocalteu reagent,
hydrogen peroxide, myoglobin, potassium ferricyanide,
potassium phosphate (monobasic and dibasic), sodium
carbonate, 1,1,3,3-tetramethoxypropane, 2,4,6-tripyridyl-
s-triazine (TPTZ), 2-thiobarbituric acid and tri-
chloroacetic acid were from Sigma Chemical Co.,
USA. 2,2′-Azobis (2-amidinopropane) dihydrochloride
(AAPH) and Trolox (6-hydroxy 2,5,7,8 tetramethyl
chroman 2-carboxylic acid) were from Aldrich Chemi-
cal Co., USA. Other chemicals used in the studies were
of the highest quality commercially available from
local suppliers. The wheatgrass tablets, used in our
studies, were purchased from local suppliers in
Mumbai and the growth condition of the correspond-
ing wheatgrass is unknown. These tablets constitute
98% of wheatgrass, 1.5% silica and 0.5% vegetable
stearates.
220 S. D. KULKARNI ET AL.
Copyright © 2006 John Wiley & Sons, Ltd. Phytother. Res. 20, 218–227 (2006)
buffer at the concentration of 10 mg protein/mL and
stored at −20 °C for further studies.
Exposure of rat liver mitochondria to oxidative stress.
Oxidative damage was induced by the ascorbate-Fe2+-
system as described elsewhere (Devasagayam, 1986b).
The reaction mixture was incubated at 37 °C in a shaker-
water bath for 30 min. The samples were then boiled
with TBA (thiobarbituric acid) reagent for 30 min. Thio-
barbituric acid reactive substances (TBARS) formed
were estimated as malondialdehyde equivalents by
measuring the absorbance at 532 nm after accounting
for appropriate blanks. A malondialdehyde standard
was prepared by the acid hydrolysis of tetramethoxy-
propane. All data are expressed as mean ± 1
σ
obtained
from three independent experiments. Correlation coef-
ficients were calculated by using Microcal Origin 6 soft-
ware. Student’s t-test was applied to calculate significant
differences between the values and p > 0.05 was consid-
ered significant.
RESULTS
Ferric reducing and ABTS radical scavenging power
of wheatgrass extracts
The results of the ferric reducing power of wheatgrass
extracts are given in Fig. 1. On average it was found
that the ratio of the fresh to dry weight of wheatgrass
was 4. Assuming that there were no additives in the
wheatgrass tablet, the content of wheatgrass tablet was
normalized by dividing it by 4. The data are expressed
as AEAC (ascorbic acid equivalent antioxidant capacity)
and TEAC (Trolox equivalent antioxidant capacity)
in the cases of the aqueous and ethanol extracts,
respectively. The values are expressed as mmol of
ascorbic acid/100 g of fresh wheatgrass in the case of
AEAC and Trolox in the case of TEAC. Aqueous
extracts and ethanol extracts showed similar FRAP
values irrespective of their growth conditions. A gradual
increase was observed with respect to the growth
period in all the conditions. The highest AEAC value
of 0.463 was observed for 15 day old wheatgrass grown
in condition 4 and the corresponding TEAC value was
0.573.
The values obtained in the ABTS assay are presented
in Fig. 2. Both extracts showed similar potential to
inhibit ABTS radical formation. Different growth
conditions as well as the growth period did not alter
the AEAC and TEAC values significantly. However,
the values of 0.928 and 0.874 AEAC and TEAC,
respectively, obtained for commercially available wheat-
grass tablet are higher than those obtained for labora-
tory grown wheatgrass.
Radical scavenging ability of extracts by DPPH assay
Figure 3 shows a comparison of the DPPH radical scav-
enging abilities of the different wheatgrass extracts.
Ethanol extracts, in general, showed higher DPPH
scavenging capacities than the aqueous extracts. The
highest DPPH scavenging potential was observed for
condition 4, for which the TEAC value increased with
range 0–1 mm (both, aqueous and ethanolic solutions).
The concentration of FeSO4 was plotted against con-
centrations of the standard antioxidants (l-ascorbic acid
and Trolox).
Inhibition of ABTS· formation assay. In the
ferrylmyoglobin/ABTS·+. The spectrophotometric assay,
the inhibition of radical formation by the extracts, was
determined using the ferrylmyoglobin/ABTS·+ proto-
col (Alzoreky and Nakahara, 2001). The calibration
curve was plotted with the lag time in seconds versus
the concentration of the standard antioxidants (l-ascor-
bic acid and Trolox).
Radical scavenging assay by using DPPH. The DPPH
scavenging effect was determined for the different
extracts (Aquino et al., 2001). In this method, a com-
mercially available, stable free radical, DPPH·, soluble
in methanol, was used. In its radical form, DPPH· has
an absorption maximum at 515 nm, which disappears
on reduction by an antioxidant compound. The calibra-
tion curve was plotted with % DPPH·
scavenged versus con-
centration of the standard antioxidants (l-ascorbic acid
and Trolox).
Determination of total phenols and total flavonoids.
For determining both, total phenolic and flavonoid
contents, calibration curves were obtained using known
quantities of standard antioxidants. The total phenolic
content of the ethanol and aqueous extracts were meas-
ured using a modified Folin-Ciocalteu method (Lowry
et al., 1951). The absorbance was measured at 750 nm.
The measured values were compared with a standard
curve of gallic acid concentrations and expressed as
millimoles of gallic acid equivalents/100 g fresh
wheatgrass. The flavonoid contents of both the extracts
were also measured (Luximon-Ramma et al., 2002).
The absorbance was measured at 368 nm. The values
obtained were compared with a standard curve of
quercetin concentrations and expressed as millimoles
of quercetin equivalents/100 g fresh wheatgrass.
Oxygen radical absorbance capacity (ORAC) assay.
The selected wheatgrass extracts were assessed for
inhibition of
β
-phycoerythrin damage induced by
peroxyl radicals from thermal decomposition of the azo
initiator, AAPH, by fluorescence measurement. The
excitation wavelength was 540 nm and the emission
wavelength was 565 nm. The fluorescence was recorded
after every 5 min, until the last reading was less than
5% of the first (0 min) reading. The ORAC values were
expressed in terms of µmol Trolox/g of fresh wheatgrass
(Cao and Prior, 2002).
Isolation of mitochondrial fraction from rat liver. Three
month old female Wistar rats (weighing 250 ± 20 g)
were used for the preparation of mitochondria. The rat
livers were excised and homogenized in 0.25 m sucrose
containing 1 mm EDTA. To remove cell debris and
the nuclear fraction the homogenate was centrifuged
at 3000 g for 10 min. The supernatant was centrifuged
at 10 000 g for 10 min to sediment mitochondria. The
mitochondrial pellet was washed thrice with 50 mm
potassium phosphate buffer, pH 7.4, to remove sucrose
(Devasagayam, 1986a) and the protein content was
estimated. These pellets were suspended in the above
ANTIOXIDANT ACTIVITY OF WHEATGRASS 221
Copyright © 2006 John Wiley & Sons, Ltd. Phytother. Res. 20, 218–227 (2006)
Figure 1. Antioxidant capacity of (a) aqueous extracts and (b) ethanol extracts of wheatgrass grown in different conditions by using
ferric reducing antioxidant power (FRAP) assay. Ascorbic acid equivalent antioxidant capacity (AEAC) and Trolox equivalent antioxi-
dant capacity (TEAC) expressed as mmol/100 g fresh wheatgrass. The values are expressed as mean ± SE of three independent
experiments.
period. The TPC is expressed as mmol equivalents
of gallic acid/100 g fresh wheatgrass. In both types of
extracts the total phenolic content was found to
increase with growth. The TPC was found to be high-
est for condition 4. The values on day 15 of growth
were 0.331 and 0.699 for aqueous and ethanol extracts,
respectively. The commercially available wheatgrass
tablet had TPC values of 0.115 and 0.189 for aqueous
and ethanol extracts, respectively.
Figures 5a and 5b present the total flavonoid con-
tents (TFC) of the aqueous and ethanol extracts of
wheatgrass as a function of growth in different condi-
tions. TFC is expressed as mmol equivalents of
quercetin/100 g of fresh wheatgrass. The TFC of the
wheatgrass extracts on day 15 of growth was 0.317 in
condition 4 in the case of the aqueous extracts and
0.779 for the ethanol extracts. The commercially
available wheatgrass tablet possessed a higher TFC with
the plant growth period, with highest the level (1.476)
being observed on day 15. In the case of aqueous
extracts, different growth conditions had no signific-
ant impact on the DPPH scavenging potential. How-
ever, the extracts corresponding to day 15 of growth
showed the highest DPPH scavenging abilities. Inter-
estingly, the commercially available wheatgrass tablet
showed a significantly lower (p < 0.02) value than
that of the wheatgrass grown in conditions 2, 3 and 4
in the case of the aqueous extracts and in condition 4
(p < 0.05) for the ethanol extracts.
Total phenolic and flavonoid contents
Figures 4a and 4b show the total phenolic contents
(TPC) of the aqueous and ethanol extracts of wheatgrass
grown in different conditions as a function of the growth
222 S. D. KULKARNI ET AL.
Copyright © 2006 John Wiley & Sons, Ltd. Phytother. Res. 20, 218–227 (2006)
Figure 2. Antioxidant capacity of (a) aqueous extracts and (b) ethanol extracts of wheatgrass grown in different conditions using the
ABTS assay. Ascorbic acid equivalent antioxidant capacity (AEAC) and Trolox equivalent antioxidant capacity (TEAC) expressed as
mmol/100 g fresh wheatgrass. The values are expressed as mean ± SE of three independent experiments.
Inhibition of lipid peroxidation induced
by ascorbate-Fe2++
++
+ system
The results of the studies on lipid peroxidation
assay are presented in Table 1. Both aqueous and
ethanol extracts showed significant protection against
ascorbate-Fe2+ induced lipid peroxidation. The ethanol
extracts were found to be more potent than the
aqueous extracts. The extracts A1 and E1 gave
56.1% and 74.2% inhibition of lipid peroxidation,
respectively. Among the aqueous extracts, the maxi-
mum protection (52.9%) was observed with the extracts
corresponding to day 10 of condition 4, whereas
among the ethanol extracts on day 10 of condition 3
gave the maximum (43.9%) protection against lipid
peroxidation.
values of 0.105 and 0.237 mmol/100 g for the aqueous
and ethanol extracts, respectively, which are lower than
those for the fresh wheatgrass.
Oxygen radical absorbance capacity (ORAC) assay
The ORAC is one of the standard assays that food
chemists and nutritionists use to check the antioxidant
capacity of food products. The ORAC values for the
aqueous extracts on day 10 of growth in conditions 1, 2,
3 and 4 were found to be 32.6, 37.4, 35.8 and 39.9,
respectively, whereas for the ethanol extracts they were
41.6, 42.4, 42.3 and 48.2, respectively. The correspond-
ing values for the commercial wheatgrass tablet were
13.8 and 17.0, respectively.
ANTIOXIDANT ACTIVITY OF WHEATGRASS 223
Copyright © 2006 John Wiley & Sons, Ltd. Phytother. Res. 20, 218–227 (2006)
DISCUSSION
It is well known that phenolic compounds including
flavonoids of plant origin are mostly responsible for
radical scavenging. They possess different antioxidant
properties that can be attributed to their therapeutic
uses in different diseases. The AEAC and TEAC val-
ues obtained from radical scavenging assays for all
extracts were correlated with the total phenolic and
flavonoid contents. With the DPPH assay, reasonable
correlations between the AEAC of the aqueous ex-
tracts and the TPC was observed (r2 = 0.49) but the
correlation with TFC was better (r2 = 0.61). In the case
of the ethanol extracts similar correlations between the
antioxidant activity (TEAC) and the TPC and the TFC
were observed with r2 values of 0.64 and 0.53, respec-
tively. With the ABTS free radical formation assay, the
aqueous and ethanol extracts, showed values of r2 =
0.56 and r2 = 0.73, respectively with TPC. A strong and
significant correlation between the flavonoid content
and the antioxidant activity of ethanol extracts (r2 =
0.94) was seen.
Wheatgrass showed higher oxygen radical absorbance
capacity (ORAC) values, which is used as a standard
tool for comparing the antioxidant capacities of food
products (Lachnicht et al., 2002). The results presented
in Table 2 showed that the values, in the range of 25–
68, are similar to or higher than those for some fruits
and vegetables. The values were in the range 10–25 for
different extracts of turmeric (Tilak et al., 2004), 19.4
for garlic, 12.6 for spinach, 4.5 for onion, 15.36 for
strawberry, 9.49 for plum and 2.10 for carrot (Lachnicht
et al., 2002).
Figure 3. Radical scavenging capacity of (a) aqueous extracts and (b) ethanol extracts of wheatgrass grown in different conditions
using the DPPH assay. Ascorbic acid equivalent antioxidant capacity (AEAC) and Trolox equivalent antioxidant capacity (TEAC)
expressed as mmol/100 g fresh wheatgrass. The values are expressed as mean ± SE of three independent experiments.
224 S. D. KULKARNI ET AL.
Copyright © 2006 John Wiley & Sons, Ltd. Phytother. Res. 20, 218–227 (2006)
Figure 4. Total phenolic content (TPC) of (a) aqueous extracts and (b) ethanol extracts of wheatgrass grown under condition 1 (tap
water), condition 2 (nutrient solution), condition 3 (soil with tap water) and condition 4 (soil with nutrient solution) as a function of
its growth period. A1 and E1 represent the aqueous and ethanol extracts of commercial wheatgrass tablet. The concentrations are
expressed as mmol gallic acid equivalents/100 g fresh wheatgrass. The values are expressed as mean ± SE of three independent
experiments.
The antioxidant activity of wheatgrass extract was
observed at various levels of protection such as pri-
mary and secondary radical scavenging and inhibition
of free radical induced membrane damage. This can
possibly be explained on the basis of its chemical con-
tent. It has been shown that these extracts contain
significant amounts of phenolic compounds including
flavonoids. Recently it was shown that during germina-
tion, some biologically active compounds were synthe-
sized in the wheat sprouts (Mancinelli et al., 1998;
Calzuola et al., 2004). Our results are consistent with
Yang et al. (2001) who concluded that wheat sprouts
reached the maximum antioxidant potential after 7 days
of plant growth. Wheatgrass, in general, has been
reported to possess therapeutic properties in diseases
such as ulcerative colitis and thalassaemia major (Ben-
Arye et al., 2002; Marwaha et al., 2004). In addition
to this, wheat sprout extracts were found to be
antimutagenic in the Ames test (Peryt et al., 1992),
capable of inhibiting oxidative DNA damage (Falcioni
et al., 2002) and responsible for metabolic deactivation
of carcinogens (Lai et al., 1978).
Our studies showed that water extracts of wheatgrass
are a good source of antioxidants. Among the condi-
tions, condition 4 showed relatively higher antioxidant
activity in all the cases, the extent of variation among
all the conditions was not very significant. The anti-
oxidant activity obtained from different assays in the
present study showed higher levels at 7 days onwards,
which is in conformity with the use of fresh wheatgrass
of growth of 7–8 days. The commercially available
wheatgrass tablet, which is prepared from wheatgrass
powder also showed significant antioxidant potential.
In view of its antioxidant potential and the ease with
ANTIOXIDANT ACTIVITY OF WHEATGRASS 225
Copyright © 2006 John Wiley & Sons, Ltd. Phytother. Res. 20, 218–227 (2006)
Figure 5. Total flavonoid content (TFC) of (a) aqueous extracts and (b) ethanol extracts of wheatgrass grown under condition 1 (tap
water), condition 2 (nutrients solution), condition 3 (soil with tap water) and condition 4 (soil with nutrient solution) as a function of
its growth period. A1 and E1 represent the aqueous and ethanol extracts of commercial wheatgrass tablet. The concentrations are
expressed as mmol quercetin equivalents/100 g of fresh wheatgrass. The values are expressed as mean ± SE of three independent
experiments.
which it can be home-grown under known environ-
mental conditions, wheatgrass extracts can be used as a
dietary supplement for antioxidant compounds such as
polyphenols and flavonoids. Although wheatgrass from
condition 4 showed slightly higher activities as well as
a higher elemental content (Kulkarni et al., 2006), it
appears better to use wheatgrass grown in perforated
plastic tops without any additives.
Acknowledgements
The authors thank Dr V.K. Manchanda, Head, Radiochemistry
Division, Bhabha Atomic Research Centre (BARC), Professor S. B.
Padhye, Head, Department of Chemistry and Professor B. S. M.
Rao, Ex-Head, for their constant support and encouragement. One
of the authors (SDK) thanks the Board of Research in Nuclear
Sciences (BRNS), Department of Atomic Energy (DAE), India
under Memorandum of Understanding (MoU) between Bhabha
Atomic Research Centre (BARC)-University of Pune.
226 S. D. KULKARNI ET AL.
Copyright © 2006 John Wiley & Sons, Ltd. Phytother. Res. 20, 218–227 (2006)
Table 1. Inhibition of lipid peroxidation in rat liver mitochondria by aqueous and ethanolic
extracts of wheatgrass on days 8 and 10 of germination
nmol TBARS/mg
Condition Extract protein Inhibition (%)
Damage – 0.5 ± 0.2 –
Control – 96.7 ± 1.5 –
Condition 1 8-AT 80.1 ± 5.7 17.2 ± 1.2
8-ET 71.8 ± 2.6 25.9 ± 2.5
10-AT 66.9 ± 1.2 30.9 ± 1.1
10-ET 54.5 ± 9.5 43.9 ± 3.4
Condition 2 8-AN 85.7 ± 2.5 11.4 ± 2.5
8-EN 66.8 ± 2.4 31.1 ± 2.4
10-AN 69.6 ± 2.6 28.2 ± 2.6
10-EN 61.4 ± 1.9 36.7 ± 1.8
Condition 3 8-AST 73.0 ± 1.4 24.6 ± 2.3
8-EST 64.9 ± 2.8 33.1 ± 2.8
10-AST 61.0 ± 1.6 37.1 ± 1.5
10-EST 54.4 ± 1.6 43.9 ± 1.5
Condition 4 8-ASN 64.2 ± 1.4 33.8 ± 1.3
8-ESN 58.5 ± 5.2 39.7 ± 5.1
10-ASN 45.8 ± 2.2 52.9 ± 2.2
10-ESN 54.8 ± 1.1 43.5 ± 1.0
Tablet A1 42.7 ± 3.4 56.1 ± 3.4
E1 25.3 ± 1.2 74.2 ± 2.1
Lipid peroxidation was measured by thiobarbituric acid reactive substances (TBARS) assay and
is expressed as nmol malonaldehyde equivalents/mg protein.
Values represented are mean ± SE from triplicate experiments.
Conditions: Condition 1, tap water; Condition 2, tap water + nutrients; Condition 3, tap water +
soil; Condition 4, nutrient + soil.
8, 10, plant growth period; A, aqueous extracts; E, ethanol extracts; T, plants grown in tap
water; N, nutrient solution; S, soil; A1, aqueous extract of commercial tablet; E1, ethanol
extract of commercial tablet.
Table 2. Oxygen radical absorbance capacity (ORAC) values of aqueous and ethanol extracts of
wheatgrass on days 8 and 10 of germination
Condition Extract ORAC valuesa
Condition 1 8-AT 25.1 ± 2.5
8-ET 40.3 ± 2.7
10-AT 32.6 ± 5.3
10-ET 41.6 ± 1.0
Condition 2 8-AN 25.6 ± 2.8
8-EN 42.5 ± 0.5
10-AN 37.4 ± 5.2
10-EN 42.4 ± 0.7
Condition 3 8-AST 27.3 ± 3.5
8-EST 42.7 ± 2.2
10-AST 35.8 ± 1.6
10-EST 42.3 ± 3.8
Condition 4 8-ASN 33.4 ± 2.0
8-ESN 45.8 ± 3.7
10-ASN 39.9 ± 2.6
10-ESN 48.2 ± 2.2
Tablet A1 13.82 ± 0.75
E1 17.01 ± 0.78
a ORAC values are expressed as µmol Trolox/g fresh wheatgrass.
Values represent mean ± SE from triplicate experiments
Conditions: Condition 1, tap water; Condition 2, tap water + nutrients; Condition 3, tap water +
soil; Condition 4, Nutrient + soil.
8, 10, plant growth period; A, aqueous extracts; E, ethanol extracts; T, plants grown in tap
water; N, nutrient solution; S, soil; A1, aqueous extract of commercial tablet; E1, ethanol
extract of commercial tablet.
ANTIOXIDANT ACTIVITY OF WHEATGRASS 227
Copyright © 2006 John Wiley & Sons, Ltd. Phytother. Res. 20, 218–227 (2006)
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