Vol.3, No.4, 291-294 (2011) Natural Science
http://dx.doi.org/10.4236/ns.2011.34037
Copyright © 2011 SciRes. OPEN ACCESS
Anti-oxidant activity and cytotoxicity of ethanolic
extracts from rhizome of Musa acuminata
Kps Adinarayana1*, Ajay P. Babu2
1Department of Anatomy, Andhra Medical College, Visakhapatnam, India; *Corresponding Author: kpsanarayana@rediffmaill.com
2Bio-Lab, Research Gateway for Biosciences, Visakhapatnam, India; dr.ajay@rgbio.org
Received 21 January 2011; revised 20 February 2011; accepted 10 March 2011.
ABSTRACT
In the present study, antioxidant activities of
rhizome of Musa acuminata were investigated.
Free radical scavenging assay (DPPH) and re-
ducing power of the ethanolic extract of banana
rhizome resulted in potential antioxidant activi-
ties. A relatively high percentage of antioxidant
activity by DPPH assay (81.41% at 200 μg/ml)
which was comparable to that of the standard,
ascorbic acid at 100 μg/ml was observed. With
the gallic acid as standard the extract showed a
relatively low reductive potential, however, when
tested for cytotoxicity at the highest concentra-
tion of the tested dose (256 μg/ml), the maxi-
mum rate of inhibition observed was 50.32%.
The present work indicates that the ethanolic
extract of Musa acuminata exhibits significant
antiproliferative and antioxidant activities.
Keywords: Antioxidant; Antiproliferative; DPPH;
Free Radical; MTT Assay
1. INTRODUCTION
It has been reported in literature that the role of free
radicals in many disease conditions was due to the reac-
tive oxygen species generated from various biochemical
reactions [1]. These are capable of damaging crucial
biomolecules and have been the major causative factor
of many chronic and degenerative diseases including
atherosclerosis, diabetes mellitus, cancer, Parkinson’s
disease and immune dysfunction [2,3]. Primary sources
of naturally occurring antioxidants are whole grains,
fruits and vegetables. Plant source food antioxidants like
vitamin C, vitamin E, carotnenes, phenolic acids, phytate
and phytoestrogens have been recognized as having the
potential to reduce risk. Moreover, antioxidants from
natural sources such as medicinal plants and vegetables
have shown to protect against oxidative stress [4]. Com-
pounds such as gallates, have strong antioxidant activity,
while others such as the mono-phenols are weak anti-
oxidants. Phenolic compounds, in particular, which are
widely distributed in many fruits, vegetables and me-
dicinal plants accounted for their antioxidant capacity of
many plants [5].
Antioxidants play major role in neutralizing the ef-
fects of free radicals and are known to be effective in
preventing the free radical formation by scavenging or
promotion of their decomposition [6]. Free radicals pre-
sent in the biological system which may oxidize nucleic
acids, proteins, lipids or DNA are entrapped by the anti-
oxidant compounds like phenolic acids, peroxide, hy-
droperoxide or lipid peroxyl inhibiting the oxidative
mechanism that lead to degenerative diseases [7,8]
Different methods published in the literature for the
determination of antioxidant activity of foods involve
electron spin resonance (ESR) and chemiluminiscence
methods. These methods measure the free radical-sca-
venging activity of antioxidants against free radicals like
the 1,1-diphenyl-2-picry;hydrazyl (DPPH) radical, the
superoxide anion (O2), the hydroxyl radical (OH), or the
peroxyl radical (ROO). The malondialdehyde (MDA) or
thiobarbituric acid-reactive-substance (TBARS) assays
[7] have been used extensively since the 1950’s to esti-
mate the peroxidation of lipids in membrane and bio-
logical systems. The ABTS [2,2’-azinobis (3-ethylben-
zothiazoline-6-sulfonic acid)] radical cation [8] has been
used to screen the relative radical-scavenging abilities of
flavonoids and phenolics [9]. Vinson et al. have meas-
ured phenoilics in fruits and vegetables calorimetrically
using the Folin-Ciocalteau reagent and determined their
antioxidant capacity by inhibition of low density lipo-
protein oxidation mediated by Cupric ions [10].
In the present study, we investigated the antioxidant
and anticancer activities of the crude extracts of rhizome
of Musa acuminata.
K. Adinarayana et al. / Natural Science 3 (2011) 291-294
Copyright © 2011 SciRes. OPEN ACCESS
292
2. MATERIALS AND METHODS
2.1. Plant Material
The rhizome of Musa acuminata was collected from
local farm in Visakhapatnam. The material was cleaned,
washed, dried and carefully powdered.
2.2. Chemicals
Folin-Ciocalteu reagent, Trichloroacetic acid (TCA)
and ascorbic acid were purchased from Merck, Mumbai,
India. Butylated hydroxytoluene (BHT) was purchased
from Sigma Chemical Co. (USA). 1, 1-diphenyl-2-
picrylhydrazyl (DPPH), Gallic acid and MTT (3-(4,
5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazoliumbromide)
were obtained from Hi Media Laboratories Pvt. Ltd,
Mumbai, India.
2.3. Extraction
Fresh rhizomes of Musa acuminata were dried under
shade and the dried material was powdered using mortar
and pestle. Ten grams of the powder was packed in filter
paper and introduced in the extraction unit of Soxhlet
extractor and extracted with ethanol for 48 h. The extract
was concentrated and subjected to anti-cancer and anti-
oxidant activities.
2.4. Determination of the DPPH Scavenging
Activity
1, 1-Diphenyl-2-picrylhydrazyl free radical scaveng-
ing assay (DPPH) was carried out according to the fol-
lowing procedure [11]. One ml of ethanolic extracts of
rhizome and standard (Ascorbic acid) at various concen-
trations (10, 50, 100, 150 and 200 μg/ml) were added to
3 ml of 0.004% DPPH in ethanol and the reaction mix-
ture was shaken vigorously. These solution mixtures
were kept in dark for 30 min and optical density was
measured at 517 nm using LT-29 labtronics spectropho-
tometer. Ethanol with DPPH was used as blank. The %
scavenging activity was calculated using the formula:
Percentage of inhibition of DPPH activity100
AB
A

where A = optical density of the blank and B = optical
density of the sample.
2.5. Determination of Reducing Power
Reducing power of the extract was determined as re-
ported [12]. The rhizome extract (10, 50, 100, 150 and
200 μg/ml) was mixed with 2.3 ml of phosphate buffer
(0.2 M, pH 6.6) and 2.5 ml of 1% potassium ferricyanide
K3[Fe(CN)6]. The mixture was incubated at 37˚C for 20
min. 10% Trichloroacetic acid (2.5 ml) was added to the
mixture and centrifuged for 10 min at 1 000 rpm; the
supernatant (2.5 ml) was mixed with 2.5 ml of distilled
water and 0.5 ml of 0.1% FeCl3. After standing for 10
min, the absorbance was measured at 700 nm. High ab-
sorbance of the reaction mixture indicates high reducing
power. All experiments were repeated at least three
times.
2.6. Cancer Cell Culture
Carcinoma of cervix (HeLa) cells were maintained in
Dulbecco’s modified Eagles medium (DMEM) supple-
mented with 4.5 g/L glucose, 2 mM L-glutamine and 5%
fetal bovine serum (FBS) (growth medium) at 37˚C in
5% CO2 incubator.
2.7. MTT Assay
The MTT assay developed by Mosmann [13] was
modified and used to determine the inhibitory effects of
test compounds on cell growth in vitro. In brief, the
trypsinized cells from T-25 flask were seeded in each
well of 96-well flat-bottomed tissue culture plate2 at a
density of 5 × 103 cells/well in growth medium and cul-
tured at 37˚C in 5% CO2 to adhere. After 48hr incuba-
tion, the supernatant was discarded and the cells were
pretreated with growth medium and were subsequently
mixed with different concentrations of extract (2, 4, 8,
16, 32, 64, 128 and 256 µg/ml) in triplicates to achieve a
final volume of 100 µl and then incubated for 48 hr. The
extract was prepared as 2.0 mg/ml concentration stock
solutions in dimethyl sulfoxide (DMSO). The final con-
centration of DMSO in the culture was within 0.2%.
Culture medium and solvent were used as controls. Each
well then received 5 µl of fresh MTT (0.5mg/ml in PBS)
followed by incubation for 2hr at 37˚C. The supernatant
growth medium was removed from the wells and re-
placed with 100 µl of DMSO to solubilize the colored
formazan product. After 30 min incubation, the absorb-
ance (OD) was read at a wavelength of 570 nm on an
ELISA reader, Anthos 2020 spectrophotometer.
3. RESULTS AND DISCUSSION
The results of the DPPH scavenging activity of the
extract (Figure 1) shows that it possesses relatively high
percent antioxidant activity (81.41% at 200 g/ml) which
was comparable to that of the standard, ascorbic acid at
100 μg/ml. All concentrations of the studied extract
demonstrated a dose-dependent DPPH radical scaveng-
ing activity.
The results of the reductive potential (Figure 2) of the
extract and that of the gallic acid standard showed that
the ethanolic extract of banana rhizome possess a rela-
K. Adinarayana et al. / Natural Science 3 (2011) 291-294
Copyright © 2011 SciRes. OPEN ACCESS
293
Figure 1. DPPH radical scavenging activity of ethanolic ex-
tract of banana rhizome as compared to the standard Ascorbic
acid.
Figure 2. Reducing power of ethanolic extract of banana rhi-
zome as compared to Gallic acid.
tively low reductive potential than the standard. This
indicates that the reducing capacity of rhizome may
serve as an indicator of its potential antioxidant activity.
3.1. MTT Assay
Mean OD values of the extract was corrected by
subtracting with the mean OD of blanks. Relative
percent inhibition activity is expressed as:
%inhibition = 100 – (corrected mean OD of sample ×
100/corrected mean OD of control)
A gradual decrease in the viability of HeLa cells was
observed in a dose-dependent manner (Table 1 and Fig-
ure 3). At the highest concentration of the tested dose
(256 μg/ml), the maximum rate of inhibition observed
was 50.32%. The morphology of the cells treated with
the extract appeared significantly different when com-
pared to untreated control cells, which could probably
due to the growth inhibitory and cell death initiating
ability of the studied ethanolic extract of banana rhi-
zome.
Table 1. Optical Density (OD) and inhibitory data of ethanolic
extract of banana rhizome at various concentrations.
Cpd conc.
(µg/ml)
Observed
ODa
corrected
ODb % viabilityc % inhibitiond
2 0.853 0.803 89.88 10.12
4 0.817 0.767 85.85 14.15
8 0.783 0.733 82.12 17.88
16 0.738 0.688 77.08 22.92
32 0.660 0.610 68.31 31.69
64 0.580 0.530 59.35 40.65
128 0.505 0.455 50.95 49.05
256 0.494 0.444 49.68 50.32
aMean of triplicates, OD at 570 nm; bCorrected OD= observed – blank OD,
Blank OD: 0.05, Control OD: 0.893; c% viability = corrected OD of sample
× 100/control OD of cell culture; d% inhibition = 100- % viability.
Figure 3. Dose-response curve of the given sample on the
growth of HeLa cells cultured in vitro.
4. CONCLUSIONS
The studied ethanolic extract of banana rhizome has
relatively low reducing power and moderate DPPH
radical scavenging activity. However, an increase in
dose-dependent treatment of extracts when exposed to
carcinoma of cervix (HeLa) cells was observed. The
results reported in this paper suggest that the ethanolic
extract of banana rhizome could be helpful in addition to
the basic medicine in treatment of a few diseases. Fur-
ther works are needed to be carried out to isolate, iden-
tify and characterize the potential antioxidant or anti-
proliferative compound(s) in the extract for potential
clinical use.
REFERENCES
[1] Halliwell, H. (1994) Free radicals, antioxidants and hu-
man disease: Curiosity, cause or consequence? Lancet,
K. Adinarayana et al. / Natural Science 3 (2011) 291-294
Copyright © 2011 SciRes. OPEN ACCESS
294
334, 1994, 721-724.
doi:10.1016/S0140-6736(94)92211-X
[2] Young, I.S. and Woodside, J.V. (2001) Antioxidants in
health and disease. Journal of Clinical Pathology, 54,
2001, 176-186. doi:10.1136/jcp.54.3.176
[3] Pourmorad, F., Hosseinimehr, S.J. and Shahabimajd, N.
(2006) Antioxidant activity, phenol and flavonid contents
of some selected Iranian medicinal plants. African Jour-
nal of Biotechnology, 5, 1142-1145.
[4] Cao, G., Sofic, E.R. and Prior, R.L. (1996) Antioxidant
capacity of tea and common vegetables. Journal of Ag-
riculture and Food Chemistry, 44, 3426-3431.
doi:10.1021/jf9602535
[5] Kaur C. and Kapoor, H.C. (2002) Antioxidant activity
and total phenolic content of some Asian vegetables. In-
ternational Journal of Food Science & Technology, 37,
153-162. doi:10.1046/j.1365-2621.2002.00552.x
[6] Maxwell, S.R.J., (1995) Prospects for the use of antioxi-
dant therapies. Drugs, 49, 345-361.
doi:10.2165/00003495-199549030-00003
[7] Dykes, L. and Rooney, L.W. (2007) Phenolic compounds
in cereal grains and their health benefits. Cereal Foods
Wor ld, 52, 105-111.
[8] Miller, H.E., Rigelhof, L.M., Prakash, A. and Kanter,
M.A. (2000) Antioxidant content of whole grain break-
fast cereals, fruits and vegetables. Journal of the Ameri-
can College of Nutrition, 19, 312-319.
[9] Prior, R., Cao, G., Martin, A., Sofic, E., McEwen, J.,
O’Brien, C., Lischner, N., Ehlenfeldt, M., Kalt, W.,
Krewer, G. and Mainland, C.M. (1998) Antioxidant ca-
pacity as influenced by total phenolic and anthocyanin
content, maturity, and variety of vaccinium species.
Journal of Agricultural and Food Chemistry, 46, 2686-
2693.
doi:10.1021/jf980145d
[10] Vinson, J.A., Hao, Y., Su, X. and Zubik, L. (1998) Phenol
antioxidant quantity and quality in foods: vegetables.
Journal of Agricultural Food Chemistry, 46, 3630-3634.
doi:10.1021/jf980295o
[11] Nooman, A.K., Ashok, K.S., Atif, A., Zaha, E. and Husni,
F. (2008) Antioxidant activity of some common plants.
Turkish Journal of Biology, 32, 51-55.
[12] Habila, J.D., Bello, I.A., Dzikwi, A.A., Musa, H. and
Abubakar, N. (2010) Total phenolics and antioxidant ac-
tivity of Tridax procumbens Linn. African Journal of
Pharmacy and Pharmacology, 4, 123-126.
[13] Mosmann, T. (1983) Rapid colorimetric assay for cellular
growth and survival: Application to proliferation and cy-
totoxicity assays. Journal of Immunological Methods, 65,
55. doi:10.1016/0022-1759(83)90303-4