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Antioxidant Properties and Total Phenolic Content of Three Varieties of Carob Tree Leaves from Morocco


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The in vitro antioxidant activity and the total phenolic content (Folin−Ciocalteu method) of three successive extracts of three varieties of Ceratonia siliqua L. leaves ( grafted female, spontaneous female, spontaneous male) grown in Morocco were investigated by using in-vitro antioxidant models including 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging assay, reducing power and total antioxidant capacity . T he global polyphenols concentration ranged from 0.45 to 2.64 (g/L GAE) in the three categories of the extracts . In each variety, ethyl acetate fraction exhibited the highest antioxidant activity compared to other fractions. Grafted female trees globally showed a higher polyphenols concentration than the spontaneous female and spontaneous male ones. Our results clearly demonstrate that all extracts have antioxidant capacity. Among the categores, the ethyl acetate extracts of carob tree leaves exhibited strong scavenging effect on 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) than the diethyl ether and dichloromethane extracts. Carob leaf extracts contain high amounts of polyphenols with strong antiradical, antioxidant capacity and reducing properties which might constitute an important source of natural antioxidants.
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The article was published by Academy of Chemistry of Globe Publications © Published 10/ 05/2010 EISSN:1307-6167
Rec. Nat. Prod. 4:4 (2010) 193-204
Antioxidant Properties and Total Phenolic Content of Three
Varieties of Carob Tree Leaves from Morocco
Hanane El Hajaji 1, Nadya Lachkar 2, Katim Alaoui 2, Yahya Cherrah 2,
Abdellah Farah 3, Abdesslam Ennabili 3, Brahim El Bali 4
and Mohammed Lachkar*1
1 Laboratoire d’Ingénierie des Matériaux Organométalliques et Moléculaires ‘’LIMOM’’, Unité
associée au CNRST (URAC 19), Faculté des Sciences, Université Sidi Mohamed Ben Abdellah,
B.P.1796 (Atlas), 30000 - Fès, Morocco
2 Laboratoire de Pharmacologie et Toxicologie, Faculté de Médecine et de Pharmacie, Université
Mohamed V, Rabat-Souissi, Rabat, Morocco
3 National Institute of Medicinal and Aromatic Plants, University of Sidi Mohamed Ben Abdellah,
BP 8862, 30100 - Fès, Morocco
4Laboratory of Mineral Solid and Analytical Chemistry, ‘’LMSAC’’, Department of Chemistry,
Faculty of Sciences, University Mohamed I, Po. Box 717, 60000 Oujda, Morocco
(Received January 23, 2010; Revised August 10, 2020; Accepted August 13, 2010)
Abstract: The in vitro antioxidant activity and the total phenolic content (Folin−Ciocalteu method) of three successive
extracts of three varieties of Ceratonia siliqua L. leaves (grafted female, spontaneous female, spontaneous male) grown in
Morocco were investigated by using in-vitro antioxidant models including 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging
assay, reducing power and total antioxidant capacity. The global polyphenols concentration ranged from 0.45 to 2.64 (g/L
GAE) in the three categories of the extracts. In each variety, ethyl acetate fraction exhibited the highest antioxidant activity
compared to other fractions. Grafted female trees globally showed a higher polyphenols concentration than the spontaneous
female and spontaneous male ones. Our results clearly demonstrate that all extracts have antioxidant capacity. Among the
categories, the ethyl acetate extracts of carob tree leaves exhibited strong scavenging effect on 1,1-diphenyl-2-picrylhydrazyl
radical (DPPH) than the diethyl ether and dichloromethane extracts. Carob leaf extracts contain high amounts of polyphenols
with strong antiradical, antioxidant capacity and reducing properties which might constitute an important source of natural
Keywords: Antioxidant activity; Phenolic content; Ceratonia siliqua L.
* Corresponding author: E-mail:; Phone: + 212 671 556 742; Fax: +212 535 733 171
Antioxidant properties of Carob tree leaves
1. Introduction
The commercial development of plants as sources of antioxidants to enhance health and food
preservation is of current interest [1]. Epidemiological studies have suggested positive associations
between the consumption of phenolic-rich foods or beverages and the prevention of diseases [2].
These effects have been attributed to antioxidant components such as plant phenolics,
including flavonoids and phenylpropanoids [3]. Antioxidants are compounds that neutralize
chemically active products of metabolism, such as free radicals which damage the body. Sources of
natural antioxidants are primarily phenolics that may occur in all products and parts of a plant such as
fruits, vegetables, nuts, seeds, leaves, roots, and bark. Due to their potential antioxidant action, plant
phenols and polyphenols, with their potential to act as antioxidants; play a major role in the prevention
of various pathological conditions such as cancer, cardiovascular and neurodegenerative diseases
believed to be associated with oxidative stress [4].
Carob tree (Ceratonia siliqua L.) is a rich plant in phenols and polyphenols and has been
widely grown under the Mediterranean Climate for a long time. It is a perennial leguminous
(Caesalpinioideae) that grows as an evergreen shrub or tree up to 10 m high, with a broad semi
spherical crown and thick trunck with brown rough bark and sturdy branches. It belongs to the
Caesalpinaceae sub family of the family Leguminoseae (= syn Fabaceae). The Carob tree has been
grown since antiquity in most countries of the Mediterranean basin, usually in mild and dry places
with poor soils. It is an important component of the Mediterranean vegetation, and its adaptation in
marginal soils of the Mediterranean regions is important environmentally and economically [5, 6]. The
Arabs disseminated it along the North African coast and north into Spain and Portugal. The Carob tree
matures slowly and bares pods in the 5th - 6th year. The flowers of the carob are very small,
inconspicuous and unisexual. Leaves are 3-7 cm long, alternate, pinnate, with or without a terminal
leaflet. Carob does not shed it leaves in the autumn but only in July every second year, and it only
partially renews leaves in spring. The production of carob pod in the world is estimated at about 315.
000 tonnes per year, Morocco is the fourth producer [7]. The production in Morocco, based on wild
populations which is very variable. It has increased during the last 15 years, and it is estimated to be
about 26.000 tonnes. The main spontaneous populations are concentrated in the regions of Tafechma
in the north and Ait Ishaq in the south. However, three areas are commercially known Fès, Marrakech
and Agadir. Acreage of spontaneous carob in Morocco is estimated to 30 000 ha. Carob tree thrives
together with a number of other species such Pistacia spp., Olea spp. Quercus spp., etc.
The two main carob pod constituents are pulp (90%) and seed (10%). Chemical composition
of the pulp depends on cultivar, origin and harvesting time [8]. Carob pulp has a high content in total
sugar, consisting of mainly sucrose, glucose, fructose and maltose. In addition, it contains about 18%
of cellulose and hemicellulose. Constituents of the carob seed are coat (30-33%), endosperm (42-46%)
and embryo or germ (23-25%) [9, 10]. The seed coat contains antioxidants [11]. The endosperm is the
galactomannan carob bean gum (CBG). Carob pod meal contained high levels of carbohydrates
(45%), appreciable amounts of protein (3%), and low levels of fat (0.6%). Germ and seed meal
contained more fat and less carbohydrates compared to the carob pod [12]. The butanol soluble
fraction of the methanol extract of the carob cotyledons contain five C-glycosylflavones including
schaftoside, isoschaftoside, neoschaftoside, isoschaftoside-4'-O-glucoside and schaftoside-4`-
Oglucoside [13]. Flavonoids represented 26% of the polyphenols and the major components were
identified as the glycosides myricetin and quercetin-3-O-α-L-rhamnoside [14, 15]. Phenolic contents
of pulps and leaves from carob tree (Ceratonia siliqua L.), have been reported [12, 16-19]. M. Balaban
has demonstrated that carob wood is characterized by its richness in gallotanins and in
proanthocyanidins [20]. New flavonol glycoside, 4`-p-hydroxybenzoylisorhamnetin-3-O-α-L-
rhamnopyranoside named ceratoside, together with the known kaempferol-3-O- α-L-
rhamnopyranoside (afzelin), quercetin-3-O- α -L-arabinofuranoside (auriculain), quercetin-3-O- α-L-
rhamnopyranoside , β -sitosterol and β-sitosterol-3-O- β -D-glucoside were isolated for the first time
from Ceratonia siliqua L. seeds [21]. D. Z. Botega et al. showed that Exxenterol, a non-extractable
tannin rich fiber, can be successfully employed as an additive to significantly prolong sunflower oil
Hajaji, Rec. Nat. Prod. (2010) 4:4 193-204
frying-life, and thus decrease the potential toxicity of the heated oil [22]. Vaya & Mahmood show that
the carob leaves are rich in flavonoids; and more than nine compounds were identified [14]. Recently,
investigators isolated and identified the major polyphenols in carob fibers [18, 23], and other studies
are on the variation and composition of phenolic compounds of carob pods [24]. Everywhere in
Morocco, pods or only seeds are used to fight diarrhea in infants, children and adults. Infusion of
carob leaves is used as an emetic for acute poisoning [25]. In Turkish folk medicine, leaves and barks
of carob tree are used as an antidiarrheal and diuretic [26, 27]. The fruits of this plant are traditionally
used as an antitussive and against warts [28, 29].
Some studies have shown the antioxidant acivity of Ceratonia siliqua L. These studies were
conducted only on carob pods and carob fruits. For example, S. Kumazawa et al. reported that carob
pod crude polyphenol had high antioxidant activity comparable to that of authentic polyphenol
compounds. Especially, it is apparent that carob pod crude polyphenol has strong effect against the
discoloration of β-carotene. [30]. Similary, M. Papagiannopoulos et al. showed that carob fiber and
carob flours have high antioxidative acivity expressed with a high DPPH radical scavenging activity
[23]. The antioxidant activity of the carob pod is attributed to the presence of phenolic compounds [18,
To the best of our knowledge, there are no such reports concerning Moroccan cultivars, so the
present work has focused to study the antioxidant activity and the total phenolic content with Folin-
Ciocalteu of the extracts of leaves of spontaneous male, spontaneous female, and grafted female carob
trees growing in Morocco.
2. Materials and Methods
2.1. Plant Material
Ceratonia siliqua L. leaves used in this experiment were sampled on productive Dkar
(spontaneous female), unproductive Dkar (spontaneous male) and Lanta (grafted female) trees from
the province of Chafchaouen (NW of Morocco) [32]. Vouchers specimens (INP211, INP212, INP213)
were identified by Professor A. Ennabili and have been deposited in the Herbarium of National
Institute of Medicinal and Aromatic Plants, Sidi Mohamed Ben Abdellah University, Fès, Morocco.
2.2. Preparation of the extracts
The air-dried leaves of Ceratonia siliqua L. were extracted in a Soxhlet apparatus with hexane
for 24 hours. The residue of the plant was dried, and then extracted with methanol/water 8:2 (v/v) by
exhaustive maceration (3*500 ml). The methanol/water extract obtained from a sample was evaporated
in order to remove the methanol, and the aqueous phase was extracted with diethyl ether (Et2O),
dichloromethane (CH2Cl2) and ethyl acetate (EtOAc), successively.
2.3. Total phenolic content
The total phenolic content was determined spectrophotometrically using the Folin–Ciocalteu
method. This test is based on the oxidation of phenolic groups by phosphomolybdic and
phosphotungstic acids (FC reagent). This reagent, based on the Slinkard and Singleton method [33],
and the early work of Singleton & Rossi [34] is a colorimetric oxidation/reduction method for
phenolic compounds. The products of the metal oxide reduction have a blue color that exhibits a broad
light absorption with a maximum at 764 nm. The intensity of light absorption at that wavelength is
proportional to the concentration of phenols. Briefly, a 20 µL of the diluted sample was added to 100
µL of Folin–Ciocalteu reagent. After 8 min, 300 µL of saturated sodium carbonate solution (25%) was
Antioxidant properties of Carob tree leaves
added. The absorbance was measured at 764 nm. The calibration curve was prepared with gallic acid
solutions ranging from 0 to 500 mg/L, and the results are given as gallic acid equivalents (GAE).
2.4. Antioxidant studies
2.4.1. Determination of free radical scavenging activity by DPPH method
Free radical scavenging activity of the sample extracts was determined spectrophotometrically
using the method of Blois [35]. This method is based on the measurement of the reducing ability of
antioxidants toward the DPPH radical. Briefly, 100 µL of various concentrations of the extract in
methanol were added to 10 mL of a methanol solution of DPPH (1.01.10-2 M). The mixture was
vigorously shaken and then allowed to stand at room temperature for 30 min in the dark. The
absorbance of the mixture was measured at 517 nm by using a double-beam UV-Visible Camspec
M550 spectrophotometer. A mixture of 100 µL of methanol and 10 mL of DPPH solution was used as
the control. The scavenging activity on the DPPH radical was expressed as inhibition percentage using
the following equation:
% Inhibition = [(AB − AS)/AB] × 100 [36]
where AB is the absorbance of the control reaction (containing all reagents except the test compound),
and AS is the absorbance of the test compound. Butylatedhydroxytoluene (BHT) was used as positive
control. The tests were carried out in triplicate. The extract concentration providing 50% inhibition
(IC50) was calculated from the graph of inhibition percentage plotted against extract concentration
(4.0, 2.0, 1.0, 0.5 and 0.25 mg/L).
2.4.2. Reducing power assay (Iron reducing activity)
The reducing power of Ceratonia siliqua leaves extracts was determined according to the
method previously described by Oyaizu [37]. Different concentrations of Ceratonia siliqua leaves
extracts (0-1 mg) in 1 ml of distilled water were mixed with phosphate buffer (2.5 mL, 0.2 M, pH 6.6)
and potassium ferricyanide [K3Fe(CN)6] (2.5 mL, 1%). The mixture was incubated at 50°C for 20 min.
A portion (2.5 ml) of trichloroacetic acid (10%) was added to the mixture, which was then centrifuged
at 3000 rpm for 10 min. The upper layer of the solution (2.5 mL) was mixed with distilled water (2.5
mL) and FeCl3 (0.5 mL, 0.1%) and the absorbance was measured at 700 nm. Increased absorbance of
the reaction mixture indicated increased reducing power. Ascorbic acid, tannic acid and gallic acid
were used as standards. Phosphate buffer (pH 6.6) was used as blank solution. All analyses were run in
triplicate and results averaged.
2.4.3. Evaluation of total antioxidant capacity by phosphomolybdenum method
The antioxidant activity of the extract was evaluated by the phosphomolybdenum method
according to the procedure described by Prieto et al. [38]. The assay is based on the reduction of Mo
(VI)–Mo (V) by the extract and subsequent formation of a green phosphate/Mo (V) complex at acid
pH. A 0.3 ml extract (25µ g/ml, 50µg/ml, and 100µg/ml) was combined with 3 ml of reagent solution
(0.6 M sulfuric acid, 28 mM sodium phosphate and 4 mM ammonium molybdate). In case of blank 0.3
mL of methanol was used in place of extracts. The tubes containing the reaction solution were capped
and incubated in a boiling water bath at 95°C for 90 min. After cooling to room temperature, the
absorbance of the solution was measured at 695 nm using a spectrophotometer. The antioxidant
capacity of each sample was expressed as ascorbic acid (A.A) equivalent using the following linear
equation established using ascorbic acid as standard: [A = 0.0037C + 0.0343; R² = 0.991] where A is
Hajaji, Rec. Nat. Prod. (2010) 4:4 193-204
the absorbance at 695 nm and C the concentration as ascorbic acid equivalent (µg/ml). The values are
presented as the means of triplicate analysis.
3. Results and Discussion
3.1. Total phenolic contents
Diethyl ether, dichloromethane, and ethyl acetate extracts of three varieties of Ceratonia siliqua
L. leaves (grafted female, spontaneous female, spontaneous male) grown in Morocco were studied for
their contents of total phenols. Table 1 shows the total phenol contents that were measured by Folin
Ciocalteu reagent in terms of gallic acid equivalent (GAE). The results showed that the total phenolic
content from different extracts of three categories of Ceratonia siliqua L. leaves ranging from 0.45 to
2.64 (g/L GAE).
Table 1. Total phenolic content of carob tree-categories leaves.
Categories Extracts Total phenolic content
(g/L GAE)
EtOAc 2.60
Et2O 0.95
CH2Cl2 0.77
EtOAc 2.50
Et2O 0.80
CH2Cl2 0.45
EtOAc 2.64
Et2O 1.52
Grafted female
CH2Cl2 0.82
The highest total phenolic content was observed in ethyl acetate extract of the three categories,
and the lowest was observed in dichloromethane extracts in all carob tree categories. The results
showed that carob tree leaves fractions contained a mixture of phenolic compounds at different levels
according to the polarity of solvent used in the extraction process, in the following order: ethyl acetate
> ethyl ether > dichloromethane. Category affected the phenolic profile with the grafted female being
generally richer in phenols. Phenolic compounds and flavonoids have been reported to be associated
with antioxidative action in biological systems, acting as scavengers of singlet oxygene and free
radicals [1].
3.2. Antioxidant studies
In the present study, three commonly used antioxidant evaluation methods such as DPPH
radical scavenging activity, reducing power assay and phosphomolybdenum method were chosen to
determine the antioxidant potential of the three varieties of Ceratonia siliqua L. leaves extracts.
3.2.1. Free radical scavenging activity
The antioxidant activity of plants is mainly due to the active compounds present in them. In
this study, nine leaves samples from three Ceratonia siliqua L. categories were investigated for their
Antioxidant properties of Carob tree leaves
radical scavenging activity and the results are shown in Figures 1-3. DPPH radical scavenging
activities of plant extracts varied from 1.17 to 61.17 %. All of the extracts tested possess radical-
scavenging activity. This activity was increased by increasing the concentration of the sample extract.
The highest antioxidant activity was observed in the ethyl acetate extract of the three categories of
Carob tree leaves than other extracts studied. The data obtained showed that the ethyl acetate extracts
presented a high activity. The lowest activity was shown by the leaves extract in dichloromethane. It
was also found that the free-radical-scavenging activity of ethyl acetate extract of grafted female
category (IC50 = 0.41 g/L) was stronger than that of ethyl acetate extract of spontaneous female
category (IC50 = 0.45 g/L) and ethyl acetate extract of spontaneous male category (IC50 = 1.50 g/L)
(Table 2).
Figure 1. Antioxidant activity of ethyl acetate extracts.
Figure 2. Antioxidant activity of ethyl ether extracts.
Figure 3. Antioxidant activity of dichloromethane extracts.
Hajaji, Rec. Nat. Prod. (2010) 4:4 193-204
From these results it can be concluded that the antioxidant activity of three categories of Carob
tree leaves is affected by the extracting solvent and the genotype [39, 40]. The ethyl acetate extract of
Ceratonia siliqua L. leaves is promising starting material for the isolation of compounds with
antioxidant activities. There is a lack of information available on the chemical composition of
Ceratonia siliqua L. leaves inducing antioxidant activity. Further phytochemical investigations on
these extracts including fractionation are needed to isolate active constituents and subsequent
pharmacological evaluation.
Table 2. IC50 (g/L) values of three fractions of carob tree-categories leaves.
Categories Sample IC50 (g/L)
EtOAc extract 0.45
Et2O extract -
Spontaneous female
CH2Cl2 extract -
EtOAc extract 1.40
Et2O extract 1.50
Spontaneous male
CH2Cl2 extract -
EtOAc extract 0.41
Et2O extract -
Grafted female
CH2Cl2 extract -
- BHT 0.21
3.2.2. Reducing power
The antioxidant activity of phenolic compounds is mainly due to their redox properties, which
can play an important role in absorbing and neutralizing free radicals, quenching singlet and triplet
oxygen, or decomposing peroxides [41]. For the measurements of the reductive ability, it has been
found that the Fe3+-Fe2+ transformation occurred in the presence of extract samples which was
postulated previously by Oyaizu [37]. Tanaka et al. have observed a direct correlation between
antioxidant activities and reducing power of certain plant extracts [42]. The reducing properties are
generally associated with the presence of reductones [43], which have been shown to exert antioxidant
action by breaking the free radical chain by donating a hydrogen atom [44]. Reductones are also
reported to react with certain precursors of peroxide, thus preventing peroxide formation. In this assay,
depending on the reducing power of antioxidant compounds, the yellow color of the test solution
changes into various shades of green and blue. Therefore, by measuring the formation of Perl's
Prussian blue at 700 nm, we can monitor the Fe2+ concentration. The reducing capacity of a compound
may serve as a significant indicator of its potential antioxidant activity. Reducing power of nine
different extracts of Ceratonia siliqua L. and standards (ascorbic acid, gallic acid, tannic acid) using
the potassium ferricyanide reduction method were depicted in Figures 4, 5 and 6.
The reducing power of the three varieties of carob tree leaves fractions increased and
correlated well with the increasing concentration. However, the reduction power of gallic acid, tannic
acid and ascorbic acid was relatively more pronounced than that of the three varieties of carob tree
leaves fractions. The reducing power of Ceratonia siliqua L. leaves ranged from 0.40 to 2.63 Abs for
0.2 mg/mL to 1 mg/mL of extract (Figures 4-6). The ethyl acetate extract displayed a higher reducing
activity compared to the ethyl ether and dichloromethane extracts. Category significantly affected the
antioxidant activity. The results of the reducing activity for the ethyl acetate extract demonstrated that
Antioxidant properties of Carob tree leaves
the higher activity was found in the grafted female, followed by respectively spontaneous male and
spontaneous female. In the ethyl ether extract and the dichloromethane extract, spontaneous male
exhibited the highest reducing power following by grafted female and spontaneous female.
Figure 4. Total reducing power of the ethyl acetate extracts.
Figure 5. Total reducing power of the dichloromethane extracts.
Figure 6. Total reducing power of the ethyl ether extracts.
Hajaji, Rec. Nat. Prod. (2010) 4:4 193-204
3.2.3. Total antioxidant capacity
The antioxidant activity for the different extracts of Ceratonia siliqua L. leaves was evaluated
by using phosphomolybdate method. It determines the total antioxidant capacity. This assay is based
on the reduction of Mo(VI) to Mo(V) in presence of the antioxidant compounds and the subsequent
formation of a green phosphate/Mo(V) complex at acidic pH, which is measured at 695 nm. Total
antioxidant capacity of Ceratonia siliqua L. leaves extracts, expressed as equivalents of ascorbic acid
g/mL of extract), is shown in Figures 7, 8 and 9. The antioxidant capacity of Ceratonia siliqua L.
leaves extracts was found to decrease in the order ethyl acetate extract > ethyl ether extract >
dichloromethane extract. All the extracts showed an increase in antioxidant capacity with an increase
in dose. The ethyl ether extract of spontaneous female showed a lower antioxidant capacity
respectively than the dichloromethane and ethyl acetate extracts. Total antioxidant capacity of ethyl
acetate extracts in the three varieties was found to be 100.00 µg, 106.81 µg and 107.30 µ g ascorbic
acid equivalents at 100 µg/mL extract concentration, respectively for spontaneous male, spontaneous
female and grafted female. This good antioxidant activity might be attributed to the presence of high
amounts of polyphenols in these extracts.
Figure 7. Antioxidant capacities of spontaneous male.
Figure 8. Antioxidant capacities of spontaneous female.
Antioxidant properties of Carob tree leaves
Figure 9. Antioxidant capacities of grafted female.
4. Conclusions
This paper deals with antioxidant activity and phenolic content of the three varieties of
Ceratonia siliqua L. leaves grown in Morocco. Leaves of carob tree contain high amounts of
polyphenol compounds. The extract showed significant activities in all antioxidant assays compared to
the reference antioxidant butylated hydroxyltoluene (BHT) and ascorbic acid (AA) in a dose
dependent manner. In DPPH scavenging assay the IC50 value of the ethyl acetate extract of grafted
female was found to be 0.41 g/L while the IC50 value of the reference standard BHT was 0.21 g/L.
Total antioxidant activity was also found to increase in a dose dependent manner. Moreover,
Ceratonia siliqua L. leaves extracts showed good reducing power. The ethyl acetate extract of leaves
of the three carob tree categories showed potent antioxidant properties and contained significant
amounts of phenolic compounds. The low antioxidant activity in dichloromethane and diethylether
extracts can be attributed to fact that the compounds are polar in nature and are not completely
extracted in dichloromethane and diethylether. These results suggest that Ceratonia siliqua L. leaves
may act as a chemopreventative agent, providing antioxidant properties and offering effective
protection from free radicals and support that Ceratonia siliqua L. is a promising source of natural
This work was financially supported by the CNRST (Centre National de la Recherche
Scientifique et Technique, Rabat, Morocco) and the Sidi Mohamed Ben Abdellah University, which
we gratefully acknowledge. The authors also thank the ADEMN Association (Chefchaouen, Morocco)
for assistance during sampling of plant material.
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© 2010 Reproduction is free for scientific studies
... Using the same procedure as for detecting tannin content, standard solutions of quercetin (20,40,60,80, and 100 g/ml) were created. Using a UV/visible spectrophotometer, absorbance for the test and standard solutions was measured at 510 nm in comparison to a reagent blank [28][29][30][31]. ...
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In the present scenario, none of the impactful drugs is available to treat inflammation and oxidative stress without any side effects. We focused on the Ocimum americanum leaf and evaluated its phytochemical composition, anti-inflammatory properties, and antioxidant potential using an ethanolic extraction method. A spectrophotometer was used to measure the leaf extract's overall phenolic content (TPC), whole tannin content (TTC), and the total amount of flavonoid (TFC). The human red blood cell (HRBC) membrane stabilisation method was used to evaluate the extract's anti-inflammatory properties, and the,-diphenyl-picrylhydrazyl (DPPH) method was used to test its antioxidant capacity. We discovered that the TPC, TTC, and TFC values for the plant extract were 131.44 g of GAE/mg, 13.7 g/GAE mg, and 164.7 g of QE/mg, respectively. With a maximal inhibition of 89.79% at a concentration of 1000 g/ml, the extract demonstrated considerable anti-inflammatory efficacy that was comparable to that of the common medicine diclofenac sodium. The extract's capacity to scavenge DPPH was likewise superior to that of the ascorbic acid standard medication, with 96.32% scavenging being seen at the highest concentration (75 g/ml). The extract from the leaf IC 50 value was 13.82±2.44 µg/ml, which was one-fourth that of ascorbic acid (51.88±3.24 µg/ml). Our results indicate that the O. americanum leaf extract has the potential to effectively treat inflammation and oxidative stress, and any useful compounds extracted from this plant could be utilized for this purpose in the future.
... The DPPH radical scavenging activities of the plant extracts ranged from 1.17 to 61.17%. The results of the analyses of the EtOAc extract demonstrated that the most active radical scavengers were found in the grafted female category (IC 50 = 0.41 g/L) followed by the spontaneous female category (IC 50 = 0.45 g/L) and the spontaneous male category (IC 50 = 1.50 g/L) [137]. Carob contains large amounts of polyphenols with strong antioxidant and antiradical power as well as reducing properties that can be an important source of natural antioxidants. ...
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The carob tree (Ceratonia siliqua L.) is currently considered one of the most valuable fruit and forest trees in various fields and sectors of activity. It is a versatile plant, belonging to the Fabaceae family. It is widely used in traditional medicine to treat many diseases such as diabetes, hypertension, and gastrointestinal disorders, given that all its parts (leaves, flowers, pods, seeds, wood, bark, and roots) are useful and hold value in many areas. Its importance has increased significantly in recent years. Originating from the Middle East, it is recognized for its ecological and industrial significance. Previous studies conducted on Ceratonia siliqua L. have revealed the presence of several compounds, including polyphenols, flavonoids, carbohydrates, minerals, and proteins. The carob tree demonstrates antihypertensive, antidepressant, anti-obesity, and antihyperglycemic activities. This plant is known for its medicinal and therapeutic virtues. Moreover, it is particularly interesting to consider the pharmacological activities of the major phytochemical compounds present in the different extracts of this plant, such as phenolic acids, for example, coumaric and gallic acids, as well as flavonoids such as kaempferol and quercetin. Therefore, this review aims to analyze some aspects of this plant, especially the taxonomy, cytogeography, traditional uses, phytochemical constituents, and pharmacological activities of Ceratonia siliqua L., in addition to its biological properties.
... The total phenolic content for P. acaciae was determined spectrophotometrically at 764 nm (Ultraviolet-Spectrophotometer, Pharmacia Biotech, double beam, Cambridge, England) using the Folin-Ciocalteu method (FC), as has previously been reported and discussed in details for the determination of total phenolic compounds in pharmaceutical dosage forms (El Hajaji et al., 2010;Labib & Aldawsari, 2015). 25 mg of the extract was dissolved 10 mL methanol. ...
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The antihyperglycemic effect of Plicosepalus acaciae (P. acaciae) extract was proven, but it still needs to be formulated into a suitable dosage form. We aimed at preparing an oral stabilized SLNs for P. acaciae with high payload, to be used as powder for reconstitution, filled into capsule or compressed into tablet. SLNs were prepared by emulsion solvent evaporation technique. Preliminary characterization was performed followed by full assessment of the optimized SLNs suspension and/or its lyophilized form: particle size, zeta potential, surface morphology, percentage entrapment efficiency (% EE), DSC, FTIR and in vitro release studies. The optimized SLNs lyophilized formula (F3L) exhibited acceptable compressibility and flowability. The reconstituted F3L showed % sedimentation volume of 91.83 %, re-dispersibility of 95%, viscosity of 764.33 cp, uniform particle size of 30.28 nm as shown by TEM, polydispersity index (PDI) of 0.16, zeta potential of -36.4 mV, % EE of 89.64 % and drug content of 97.69 %. The physical mixture and F3L FTIR spectrum indicated compatibility of components. In vitro release study showed a burst release in lyophilized formulations followed by slow-release, calculated as total phenolic content. Our previously reported work revealed that the total extracts of P. acaciae and SLNs formulations with the greatest lipid content F3s, demonstrated a considerable blood glucose-lowering effect in diabetic rats. The obtained lyophilized SLNs is promising for preparation of a suitable stable dosage form for P. acaciae extract to be used in treatment of diabetes.
... In the phosphomolybdenum method, the reducing power is generally associated with the presence of reductones (mainly polyphenols), which act by their antioxidant effect in a way such that they break the free radical chain by providing a hydrogen atom [30]. The reducing capacity of compounds can serve as an important indicator of their potential antioxidant activity [31]. Taking the above into consideration, in order to achieve the most accurate results, it is necessary to use several methods based on different principles when measuring antioxidant activity. ...
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The aim of this study was to determine antioxidant activity (DPPH and phosphomolyb-denum method), polyphenols content (total polyphenols, flavonoids, and phenolic acids), mineral compounds composition (Cu, Zn, Mn, Fe, Cr, Ni, Co, Pb and Cd) and antimicrobial activity (with disc diffusion method) of medicinal herbs traditionally used in the Slovak republic. The tested plants belonged to the Primulaceae, Urticaceae, Grossulariaceae, Rosaceae, Lamiaceae, Asteraceae, Equisetaceae, Tropaeolaceae, and Plantaginaceae families. The highest antioxidant activities were found in samples of Rosa canina L. (DPPH-29.43 ± 0.11 mg TE/g; TE-Trolox equivalent) and Fragaria vesca L. (phosphomolybdenum method-679.56 ± 3.06 mg TE/g), both from the Rosaceae family. Total polyphenols (determined using the Folin-Ciocâlteu-reagent) were most abundant in a sample of Fragaria vesca L.-124.51 ± 5.05 mg GAE/g (GAE-gallic acid equivalent), total flavonoids (determined using the aluminum chloride method)-in a sample of Primula veris L.-48.35 ± 3.77 mg QE/g (QE-quercetin equivalent), and total phenolic acids (determined using Arnova reagent)-in a sample of Thymus serpyllum L.-102.31 ± 2.89 mg CAE/g (CAE-caffeic acid equivalent). Regarding mineral compounds composition, samples of Fragaria vesca L. and Thymus serpyllum L. showed the highest levels of iron. In samples of Calendula officinalis L. and Trapaeolum majus L., the highest amounts of zinc were determined, while copper was the most abundant in samples of Urtica dioica L. and Melissa officinalis L. The amounts of heavy metals were within legally acceptable limits. The extract of Equisetum arvense L. showed the strongest inhibitory activity towards Clostridium perfrin-gens CCM 4991 (6 mm), while the one from Mentha piperita L.-towards Candida glabrata CCM 8270 (4.83 mm) and Candida tropicalis CCM 8223 (4.33 mm).
... It is clear that with addition of FSO, phenolic content and antioxidant activity of the leather considerably increased as flaxseed is rich in phenolic compounds such as lignan, secoisolariciresinol diglucoside (11.9-25.9 mg/g dry weight basis), and ferulic acid glucoside (1.6-5.0 mg/g dry weight basis) (El Hajaji et al., 2010;Goyal et al., 2014). In this study, 5% encapsulates of flaxseed oil were added to the leather, as the main aim was to develop a functional fruit leather incorporated with flaxseed oil. ...
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Banana fruit leather enriched with flaxseed oil in the form of encapsulates was prepared. Initially, the optimized conditions of 836 W power for 4 min for blanching of banana using microwave were obtained by Response Surface Methodology with residual polyphenol oxidase activity and vitamin C retention taken as responses. The addition of maltodextrin, citric acid, and pectin for blending with banana puree to obtain a non sticky puree having low pH was also optimized, while keeping the quantity of sugar constant. The blend was added with 5% encapsulates of flaxseed oil (FSO) in alginate used as wall material. The blend was dried in a tray drier at 40, 50, and 60°C and the drying behavior of the leather was studied. Henderson and Pabis model satisfactorily described the drying kinetics of banana leather. GAB model described well the sorption behavior of the leather. Fat content in the optimized leather increased to 3.27% due to addition of FSO. The ash content in the enriched leather was 5.56 ± 0.03%. Phenolic content increased from 91.84 ± 0.06 mg GAE/100 g to 100.90 ± 0.05 mg GAE/100 g for the enriched leather as compared to the control. The study revealed that the banana leather can be considered as a functional snack food due to the availability of flaxseed oil (rich in ω‐3 fatty) and high phenolic acid content. Practical Applications Banana can be processed into functional fruit leather with the addition of flaxseed oil encapsulated beads to complement the fast moving consumer goods market. Developing the banana leather by drying enhances its shelf life while encapsulation increases the stability of flaxseed oil for a prolonged storage of the product. Flaxseed oil is rich in ω‐3 fatty acid, an important bioactive compound required for good human health. Moreover, modeling of the drying behavior allows optimization of the process, which is necessary for designing of energy efficient industrial flow dryers. Therefore, this study on development of a novel functional product and drying kinetics will give a new edge to the industrial processing of similar snack products with a potential alternative to reduce the waste of banana as a raw material.
... [33] The reducing power of seed extracts of Apium leptophyllum was determined by various researchers to evaluate its antioxidant property; they have reported concentration dependent effect of Apium leptophyllum. [34,19] The antioxidant activities of Apium leptophyllum are shown in Table 4. ...
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Apium leptophyllum seeds are used as an important drug in Ayurveda from ancient times. The main constituents of the seed are fats, fibre, carbohydrates and essential oils, about 50% of which consists of Thymol. Chromatographic analysis of the seed showed various essential compounds viz. Pentacosanol, β-Sitosterol, 1-nonadecanol, 8-hydroxy cuminic acid, Corosolic acid and Stigmasterol. The seeds have shown strong antioxidant properties along with various other pharmacological properties like anti-microbial, anti-fungal, anti-diabetic, anti-inflammatory, anti-diarrheal, anti-asthmatic and anti-cancer properties. This review aims to provide a comprehensive overview of scientific research literature on the chemical composition and pharmacological activities of Apium leptophyllum. We are the first to report vast and updated review of this plant, as much of the work has not been done on this plant. So this review may be helpful for the researchers to explore the pharmacological properties of this plant which may lead to new discoveries in drug development.
... C.siliqua plant was characterized by the richness in secondary metabolites especially Flavonoids and phenolic acids. Many studies have identified the mainly compounds metabolites in leaves as following : gallic acid, p-hydroxybenzoic acid, chlorogenic acid, coumaric acid, ferulic acid, syringic acid, gentisic myricetinglucoside, myricetinrhamnoside, 1,6-di-Ogalloyl-gucose, 1,2,6-tri-O-galloyl-gucose and 1,2,3,6-tetra-O-galloyl-gucose[19,56,57,58,18,38] reported in Stavrou & Kapnissi-Christodoulou ...
... Furthermore, a variety of bioactive compounds were found in all parts of Ceratonia siliqua L., (leaves, pods, and seeds), such as phenolic acids, flavonoids, tannins, and alkaloids, as well as nutritional compounds, such as vitamins, protein, lipids, and minerals. [19,20]. ...
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The present work was designed to investigate the effects of different extraction processes, namely ultrasonic-assisted, supercritical fluid, microwave-assisted and Soxhlet applied to carob pods. The total phenolic quantification and the antioxidant activity were assessed by the means of rapid in vitro spectrophotometric assays; the phenolic profile was identified using ultra-high performance liquid chromatography coupled to mass spectrometry. The results revealed that the phenolic compounds and the antioxidant capacity varied significantly with the nature of the extraction process. The content of total phenolic compounds ranged from 11.55 to 34.38 mg GAE/g DW; the content of total flavonoids varied from 3.50 to 10.53 mg QE/g DW, and the content of condensed tannins fluctuated from 3.30 to 6.55 mg CE/ g DW. All extracts performed differently on antioxidant activity when determined by the DPPH assay producing a dose-dependent response, with IC50 extended from 11.33 to 6.07 µg/mL. HPLC analysis enabled the identification of nine compounds. As a function of the studied extraction methods, the phenolic compound contents were positively correlated with antioxidant activity.
... The absorbance is measured at 517 nm using a UV-visible spectrophotometer. The antiradical activity is estimated in the percentage of inhibition with the following formula [16]: ...
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The Ceratonia siliqua L seed extract was extracted using different extraction methods. The characterization and identification of bioactive compounds were carried out using the HPLC-DAD. The quantification of the polyphenol and flavonoid in the cold maceration and Soxhlet extract shows a high content of both phenolic compounds in the carob seed extract with the following values of 14, 713 mg A-G/g E, 19.25 mg A-G/g E of polyphenol content and of 1.92 mg-Q/g E and 2.47 mg-Q/g E of flavonoid content respectively. In similar, the antioxidant activity of the obtained extracts by the DPPH method shows a great capacity to trap the DPPH radical with an IC50 value of 0.041 and 0.014 mg/ml for maceration extract and Soxhlet respectively. The theoretical study using Monte Carlo simulation provides a good estimation of the interaction process between antioxidant agents and DPPH, these results are totally in accordance with data obtained experimentally.
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The plant Sarcostemma brevistigma (family-Asclepiadaceae) commonly known as "Kodikali" is used in many ayurvedic formulations. The present study was designed to evaluate the in vitro antioxidant potential of an ethanolic extract of Sarcostemma brevistigma. In vitro antioxidant activity was carried out by the reducing power assay, DPPH radical scavenging activity, Hydroxyl radical scavenging activity, Nitric oxide radical inhibition assay, Superoxide radical scavenging activity, Phosphomolybdenum assay and Determination of total phenolic content. The antioxidant activities of the study plant were found to increase with an increase in concentration. The extract exhibited the maximum reductive capacity, which was more or less equivalent to standards. The ethanolic extract (10, 20, 40, 60, 80 & 100 μg/ml) was compared with Ascorbic acid and Quercetin as a standard. The results of the present study clearly indicated that an ethanolic extract of Sarcostemma brevistigma possesses powerful in vitro antioxidant activity.
The popular uses of 76 officinal plants in Mussomeli area, Sicily, Italy are reported. A comparison of data obtained in this study against the Italian literature has revealed some unknown phytotherapeutic applications.
A fully automated-continuous flow 40-sample/ hour procedure was adapted from the Singleton-Rossi method of analysis for total phenols in wine and other plant extracts. It was compared with small-volume manual and semiautomated versions of this analysis. The agreement in mg of gallic acid equivalent phenol (GAE) per liter among a series of dry wines was excellent by all three procedures. The coefficients of variation in replicate analyses averaged 5.8% for the manual, 6.2% for the semi-automated and 2.2% for the automated procedure. This greater reproducibility, plus savings of about 70% in labor and up to 40% in reagents, makes the automated procedure attractive for laboratories doing enough total phenol analyses to recoup the cost of the automating equipment. For continuous flow, color development with the Folin-Ciocalteu reagent in alkaline solution must be hastened by heating compared to slower room temperature development for the manual methods. Heating of sugar-containing samples in the alkaline solution gives interference presumably from endiol formation. Examples are given of corrections which were used successfully to estimate the true phenol content of sweet wines.
Maillard reaction products (MRP) were prepared by refluxing the mixture of L-histidine and D-glucose (1:3 molar ratio) in 0.1M phosphate buffer (pH 5, 7, and 9) for up to 24h. It was found that antioxidative effect of MRP increased as a function of reaction time, particularly at the later stage of the reaction. At higher initial pH, antioxidative effect of MRP became significant. It was also revealed that antioxidative effect exponentially increased as a function of the development of reducing power. MRP also retarded autoxidation of sardine oil, but their antioxidative effect to sardine oil was less than that to linoleic acid. Since POV of sardine oils which had been already oxidized (POV about 50 or 100) was decreased to some extent by the addition of MRP, it was sug-gested that MRP worked as peroxide destroyers besides autoxidation-breakers. Application of MRP (pH 9, 24h heating) to Kamaboko-type sardine products (boiled or deep-fried) was also performed. MRP were mixed in sardine minced meats at the levels of 0-5%. and the products were stored at 4°C. It was found that MRP effectively inhibited autoxidation of sardine products during storage.