BEPLS Vol 5  April 2016 42 | P a g e ©2016 AELS, INDIA
Bulletin of Environment, Pharmacology and Life Sciences
Bull. Env. Pharmacol. Life Sci., Vol 5  April 2016: 42-47
©Academy for Environment and Life Sciences, India
Online ISSN 2277-1808
Global Impact Factor 0.533
Universal Impact Factor 0.9804
ORIGINAL ARTICLE OPEN ACCESS
Antioxidant Activity, Total Phenolic Content, and GC-MS Analysis
of the root of Kawilan (EmbeliaphilippinensisA. DC.)
Nyzar Mabeth O. Odchimar1, Olga M. Nuñeza1*, Mylene M. Uy2, W.T.P.S.K. Senarath3
1Department of Biological Sciences, Mindanao State University – Iligan Institute of Technology,
2Department of Chemistry, Mindanao State University – Iligan Institute of Technology, Philippines
3Department of Botany, University of Sri Jayewardenepura, Sri Lanka
*Corresponding author’s Email: firstname.lastname@example.org
The root of “kawilan” (Embeliaphilippinensis) is known by the Talaandig tribe of Bukidnon, Philippines to cure tumors,
cysts, and few types of cancer yet it lacks scientific authentication of its medicinal properties. In the present study, the
antioxidant activity of aqueous and methanol extracts of E. philippinensis roots was evaluated by determining the free
radical scavenging activity using 2,2 diphenyl-2-picrylhydrazyl hydrate (DPPH)assay method and substantiated by total
phenolics content (TPC) by Folin-Ciocalteu’s assay method. GC-MS analysis of methanol extract was also performed to
identify the specific semi-volatile chemicals present. Both aqueous and methanol root extracts showed high DPPH
inhibition activity at high concentrations. However, the aqueous root extract of E. philippinensis showed higher DPPH
inhibition activity than methanol root extract. The TPC assay showed higher phenolics content on the methanol extract.
Furthermore, GC-MS analysis revealed the presence of bioactive compounds with known antioxidant properties: (a) 9,12-
octadecadienoic acid, methyl ester, (b) eicosane, (c) hexadecane (d) hexadecanoic acid, methyl ester, (e) 9, 12,
octadecatrienoic acid, (Z,Z), (f) 9, 12, 15- octadecatrienoic acid, (Z,Z,Z), (g) n-hexadecanoic acid, (h) squalene, (i) phenol,
2,4-bis (1,1-dimethyl), and (j) 1,2-benzenedicarboxylic acid, bis (2-methylpropyl) ester. Results indicate that E.
philippinensis possesses antioxidant properties, which may account for its folkloric medicinal uses.
Keywords: bioactive compounds, DPPH assay, Folin-Ciocalteu’s assay, free radical scavenging, medicinal.
Received 12.02.2016 Revised 24.02.2016 Accepted 20.03.2016
Free radicals are generated from the by-products of normal metabolic endogenous processes  and
from the reaction with exogenous sources such as oxygen which generates reactive oxygen species (ROS)
. ROS such as superoxide radicals, hydroxyl radicals, singlet oxygen and hydrogen peroxide have
unpaired electrons which make them highly unstable and highly reactive . Being unpaired and
aggressive, they attempt to steal electrons from other neighboring molecules which can lead to a
destructive chain reaction and eventually causes oxidative stress in the body . Oxidative stress is the
overproduction of free radicals in the body system, which is capable of reversibly or irreversibly
damaging compounds of all biochemical classes, including nucleic acids, proteins and free amino acids,
lipids and lipoproteins, carbohydrates and other macromolecules . Thus, oxidative stress is implicated
in the pathogenesis of ageing, immunodepression, atherosclerosis, inflammation, diabetes,
cardiovascular, and neurological disorders [6, 7]. Importantly, in carcinogenesis and tumor-bearing
cancer, oxidative stress has been implicated . It has a particular role in DNA damage leading to various
mutations [9, 10]. Specifically, reactive oxygen species acts directly or indirectly by altering gene
expression particularly the DNA binding of transcription and signaling factors  which at some rate
causes the onset or contribute to the metastatic potential of cancer and/or tumor formation . However,
studies have shown that free radicals, in vitro, can be stabilized by the application of an anti-oxidant.
Antioxidants are chemical substances that inhibit free radical activities by donation of the missing
electrons without joining the chain of reactions . There are synthetic and naturally occurring anti-
oxidants. The synthetic antioxidants, however, impose potential health risks and toxicity . They have
been reported to induce liver and kidney dysfunction, and carcinogenic effect in experimental animals,
thus, naturally occurring antioxidants are preferred . They occur naturally in plants mainly in the
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form of phenolic compounds . Plant phenolics are reported as the most abundant secondary
metabolites found in plants, with approximately 8,000 known to date . Phenolics (phenols or
polyphenols) are chemical component responsible for a plant’s color, flavor, odor and oxidative stability
. They are compounds possessing one or more aromatic rings with one or more hydroxyl groups .
Flavonoids, tannins, and phenolic acids are the major groups of compound belonging to plant phenolics
. These compounds are known to have anti-inflammatory and anti-carcinogenic property  as well
as free-radical scavenging property . Thus, damaging effects of free radicals can be prevented by
treatment using naturally occurring medicinal plant which is already scientifically accepted . Hence,
plant diet rich in phenolics is gaining medical interest. In vitro, antioxidant activity of a medicinal plant
can be investigated through 2, 2 diphenyl-2-picrylhydrazyl hydrate (DPPH) assay method which is the
most used method in determining the free radical scavenging property of the plant extract . DPPH is a
stable free radical which readily accepts an electron or hydrogen radical donated from the antioxidants,
which converts and neutralizes the free radical 2-2 diphenyl-2-picryl hydrazyl hydrate to 1-1 diphenyl-2-
picrylhydrazine . Neutralization of DPPH is indicated in the discoloration of the reaction mixture from
violet to yellow . Embeliaphilippinensis, from the family Primulaceae, is a woody climbing vine which
can be found in the deep forest of Mt. Kitanglad, Philippines. It’s roots, by decoction, is one of the most
used herbal medicines of the Talaandig tribe of the Philippines being traditionally used as sedative, and
anti-hypertensive, but prominently used for eliminating tumors or cysts, and treating few types of
cancers . There were no recent scientific investigations on E. philippinensis roots and its antioxidant
activity. Thus, the present study aimed to determine the antioxidant properties of the root of E.
philippinensis using DPPH assay method with determination of its total phenolics content.
Fresh roots of Embeliaphilippinensiswere collected at the deep forest of Lilingayon, Valencia City,
Bukidnon, Philippines. Prior to collection, Gratuitous Permit from Department of Environment and
Natural Resources of the Philippines and an official permission from the local government were obtained.
The collected roots were washed thoroughly and air-dried until crispy. The dried plant materials were
pulverized using an electric blender and were subjected to two types of extraction: decoction and
maceration. In decoction, 10 grams of powdered root of E. philippinensis were allowed to boil with 400 ml
distilled water on a medium heat until the volume was reduced to approximately 50 ml. In maceration,
same amount of powdered root was soaked with 100 ml of 70% methanol in a shaker (100 rpm)
continuously for seven days at 26°C. Both filtrates were collected by passing through Whatman no.1 filter
paper and were subjected to rotary evaporator, 60°C for decoction filtrates and 50°C for maceration
filtrates, to obtain the aqueous and methanol crude extracts. The crude extracts were stored in a tight
glass container at 4°C until used. The samples were then subjected to DPPH assay method to determine
the free radical scavenging activity of the plant extracts.DPPH (2, 2 diphenyl-2-picrylhydrazyl hydrate)
(Sigma) scavenging activity was determined using a spectrophotometric method . Freshly prepared
DPPH solution was used. Reaction mixture was prepared using 2.5 ml of 6.5x10-5 M DPPH solution and
0.5 ml of sample extracts dissolved in methanol. Methanol was used as the control. Samples were tested
in four concentrations (0.25 mg/ml, 0.50 mg/ml, 1.0 mg/ml, and 2.0 mg/ml) with three replicates. Both
set-ups were placed untouched for 30 minutes in the dark at room temperature. Absorbance was
measured at 517 nm using UV-Vis spectrophotometer (SHIMADZU UV mini 1240). The percentage of
DPPH radical scavenging activity was determined using the equation mentioned below. IC50 value was
% DPPH scavenging activity = (Acontrol – Asample/ Aco ntrol) x 100
To further lend support on the antioxidant activity of E. philippinensis root extracts, total phenolics
content and GC-MS analysis were done to determine and evaluate possible compound responsible for the
activity. The total phenolics content was determined using Folin-Ciocalteu’s assay . A 100 µL of the
extract in methanol (1mg/mL) was mixed with 1.0 mL of distilled water and 0.5 mL of Folin-Ciocalteu’s
reagent (1:10 v/v). After mixing, 1.5 mL of 2% aqueous sodium bicarbonate was added and the mixture
was allowed to stand for 30 min with intermittent shaking. The absorbance was measured at 765nm
using a spectrophotometer (SHIMADZU UV mini 1240). A standard calibration plot of absorbance values
of Gallic acid was measured at different concentrations (64 µg/ml, 32 µg/ml, 16 µg/ml, and 8 µg/ml, 4
µg/ml). Methanol was used as a blank and the assay was carried out in triplicates. GC-MS analysis was
performed according to Chipitiet al.  with modifications. The methanol root extract of E. philippinensis
was analyzed and wasdiluted with chloroform. The sample was subjected to Agilent Technologies 7890A
GC system coupled with (an Agilent) 5975C Mass Selective detector. A HP-5MS capillary column (30 m x
0.25 mm internal diameter, 0.25 µm film thickness) was used. The carrier gas was helium. The injector
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temperature was set at 320°C. The initial oven temperature was at 70°C which was programmed to
increase to 280°C at the rate of 10°C/min with a hold time of 4 min at each increment. Injections of 1 µL
were made in split mode with a split ratio of 100:1. The mass spectrometer was operated in the electron
ionization mode at 70 eV and electron multiplier voltage at 1859 V. Other MS operating parameters were
as follows: ion source temperature 230°C, quadrupole temperature 150°C, solvent delay 3 min and scan
range 33-550 amu. The compounds were identified by direct comparison of the mass spectrum of the
analyte at a particular retention time to that of a reference standard found in the National Institute of
Standards and Technology (NIST) library. At least 80% similarity index was considered significant .
Total GC-MS running time was 45 minutes.
Table 1 shows the scavenging activity of the extracts which are evident in both the aqueous and the
methanol extracts indicated by the concentration dependent increase in the % inhibition. It also showed
that the aqueous root extract of E. philippinensis (IC50= 0.3286 mg/ml)has lower IC50 value than the
methanol extract (IC50= 0.6203 mg/ml).
Table 1.DPPH – Radical Scavenging Activity of E. philippinensis root extracts.
Extract 0.25mg/ml 0.5mg/ml 1mg/ml 2mg/ml IC
Methanol 43.79±2.74 44.92±2.09
To further ascertain the antioxidant activity of E. philippinensis root extracts, total phenolics content was
assessed since phenolics are compounds with known free radical scavenging activity . The total
phenolics content, calculated using a standard curve, of E. philippinensisaqueous and methanol root
extracts is presented in Table 2. The results showed that the aqueous extract have lower phenolics
content at 42.16 mg GA/g extract than methanol extract with 131.10 mg GA/g extract.
Table 2. Total Phenolics content of E. philippinensis root extracts.
Total Phenolics Content, GAE
Extracts mg GA /g of extract
Meanwhile, the GC-MS analysis of the methanol root extract of E. philippinensis revealed the presence of
(a) 9,12-octadecadienoic acid methyl ester, (b) eicosane, (c) hexadecane (d) hexadecanoic acid methyl
ester, (e) 9, 12-octadecatrienoic acid, (f) 9, 12, 15- octadecatrienoic acid, (g) n-hexadecanoic acid, (h)
squalene, (i) 2,4-bis(1,1-dimethyl) phenol, and (j) 1,2-benzenedicarboxylic acid, bis (2-methylpropyl)
ester (Table 3) which are previously known to possess antioxidant activity.
Table 3. Possible Compounds Found in the Methanolic Extract of E. philippinensis roots.
Name of Compound Similarity
9,12-octadecadienoic acid methyl ester 98 20.810
1,2-benzenedicarboxylic acid bis(2-
Eicosane 97 19.874
Hexadecane 97 24.957
Hexadecanoic acid methyl ester 95 19.169
9, 12-octadecadienoic acid 95 21.187
9, 12, 15-octadecadienoic acid 94 20.869
n-hexadecanoic acid 92 19.525
Squalene 92 27.035
2,4-bis(1,1-dimethyl) phenol 90 14.646
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The concentration-dependent increase in the DPPH percent inhibition of the aqueous and methanol root
extracts of E. philippinensis indicates that it has a free radical scavenging property, thereby, antioxidant
activity. Moreover, IC50 which is the concentration of sample at which the inhibition percentage reaches
50%, has an inverse relationship to the activity of a sample. The lower the IC50 value, the higher is the
activity. Results indicated that the aqueous extract has higher free radical scavenging activity than the
alcohol extract. This is in agreement with the study conducted by Chanda et al.  in which decoction
extract of Syzygium cumini leaves showed higher free radical scavenging activity than the 80% methanol
extract. The results of total phenolics content of E. philippinensis aqueous and methanol root extract are
opposite to that in the free radical scavenging assay. The methanol extract exhibited higher total
phenolics content than the aqueous extract. Other studies have shown the same inverse relationship
results on free radical scavenging activity and total phenolics content for aqueous and methanol extracts
[30, 31]. This suggests that phenolic compounds are not the predominant antioxidant components in E.
philippinensis aqueous root extract. Other compounds with antioxidant properties like alkaloids ,
terpenes [33, 34], sterols [35, 36], saponin , and many more may have contributed to these activities
exhibited by the methanol extract against DPPH radical. In addition, Folin-Ciocalteau reagent is sensitive
in recognizing oxidizable phenolics only . Moreover, phenolics content of the sample can be
negatively affected by other competing pre-existing oxidants present during the reaction period . The
aqueous extract of E. philippinensis may contain several pre-existing oxidants which can affect the results
of Folin-Ciocalteau assay. This may explain the negative correlation between aqueous and methanol
extract’s DPPH scavenging activity and total phenolics content.
The GC-MS analysis of the methanol root extract of E. philippinensis revealed the presence of Squalene,
which is a known anti-carcinogenic and antioxidant , thus, the free radical scavenging activity of the
plant is expected. Moreover, the GC-MS also revealed the presence of 2, 4-bis (1, 1-dimethyl) phenol,
which is the only known phenolics identified. The other compounds belong to hydrocarbons, alkanes,
esters, fatty acids, and terpenes. This further indicates that phenolic compounds arenot the only group of
compound contributing to the antioxidant activity of the E. philippinensis roots.
The results from the study indicated that the aqueous and methanol extracts of E. philippinensisroots have
antioxidant activities as shown in the DPPH scavenging activities of the extracts. This study also revealed
that aside from phenolics there are other compounds which may be responsible for the antioxidant
activity of the methanol extract. The free radical scavenging effects of the aqueous extract were higher
than the methanol extract suggesting that the use of the ethnobotanical preparation (decoction) of the
root of E. philippinensisin the treatmentof the diseasecan be supported.
The authors wish to thank the Department of Science and Technology –Accelerated Science and
Technology Human Resource Development Program (DOST-ASTHRPDP) of the Philippines for the
funding support. We also thank the key informant, Datu George T. Antihao, who willingly shared his
knowledge on the medicinal plants of the Talaandigs and the local officials especially Barangay Captain
Rey Bonilla for allowing us to conduct this study in the area.
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CITATION OF THIS ARTICLE
OdchimarN M O,NuñezaO M, Uy M S, Senarath WTPSK. Antioxidant Activity, Total Phenolic Content, and GC-MS
Analysis of the root of Kawilan (Embeliaphilippinensis A. DC.).Bull. Env.Pharmacol. Life Sci., Vol 5 April 2016: 42-47
Odchimar et al