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In this study, the antibacterial activity of methanol extract of henna (Lawsonia inermis) leaves, ethanol extract of pomegranate (Punica granatum) peel, volatile oil of sesame (Sesamum indicum) and peanut (Arachis hypogaea) were investigated against some Gram-positive and Gram-negative bacteria includingStaphylococcus aureus, Bacillus cereus, Escherichia coli and Acinetobacter sp. Henna extract was most effective substrate against all tested bacteria followed by pomegranate and peanut while sesame was less effective. All extracts were screened for their antibacterial activity in combination with commonly used antibiotics, including ciprofloxacin and erythromycin to evaluate synergistic effects using Minimum inhibitory concentrations (MIC) method which determined by microbroth dilution assays. Different interactions (synergistic and indifference) were observed between plant extracts and used antibiotics. The fractional inhibitory concentration (FIC) index ranged from 0.01 to 1.25 for B. cereus, 0.5 to 1 for P. aeruginosa, 0.01 to 0.3 for S. aureus and 0.06 to 0.25 for A. baumannii. The best synergistic capacity appeared between erythromycin and sesame. In vitro interaction between antimicrobial agents in combination with tested plant extracts showed synergistic effects. The MICs of each antibiotic was decreased to half when it is used in combination with tested plant extracts. This decreasing in MICs was observed in all plant extracts against tested bacteria as well as the extracts exhibited weak antibacterial activity alone.
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p-ISSN: 2663-628X
e-ISSN: 2663-6298
Suzan A. Shareef a,
*, Abdulilah S. Ismaeil b, Akhter A. Ahmad b
a Dept. of General Sciences, College of Basic Education, Salahaddin University, Kurdistan Region, Iraq –
b Dept. of Biology, College of Science, Salahaddin University, Kurdistan Region, Iraq – (abdulilah.ismaeil; akhter.ahmed)
Received: Nov., 2019 / Accepted: Feb., 2020 / Published: Mar.,2020
In this study, the antibacterial activity of methanol extract of henna (Lawsonia inermis) leaves, ethanol extract of pomegranate
(Punica granatum) peel, volatile oil of sesame (Sesamum indicum) and peanut (Arachis hypogaea) were investigated against some
Gram-positive and Gram-negative bacteria including Staphylococcus aureus, Bacillus cereus, Escherichia coli and Acinetobacter
sp. Henna extract was most effective substrate against all tested bacteria followed by pomegranate and peanut while sesame was
less effective. All extracts were screened for their antibacterial activity in combination with commonly used antibiotics, including
ciprofloxacin and erythromycin to evaluate synergistic effects using Minimum inhibitory concentrations (MIC) method which
determined by microbroth dilution assays. Different interactions (syne rgistic and indifference) were observed between plant
extracts and used antibiotics. The fractional inhibitory concentration (FIC) index ranged from 0.01 to 1.25 for B. cereus, 0.5 to 1
for P. aeruginosa, 0.01 to 0.3 for S. aureus and 0.06 to 0.25 for A. baumannii. The best synergistic capacity appeared between
erythromycin and sesame. In vitro interaction between antimicrobial agents in combination with tested plant extracts showed
synergistic effects. The MICs of each antibiotic was decreased to half when it is used in combination with tested plant extracts.
This decreasing in MICs was observed in all plant extracts against tested bacteria as well as the extracts exhibited weak antibacterial
activity alone.
KEYWORDS: Antibacterial activity; Combination; Minimum inhibitory concentration (MIC); Plant extract; Synergistic.
Infectious diseases caused by bacteria and fungi affect
millions of people worldwide. Throughout the history of
mankind, infectious diseases have remained a significant
cause of death and disability; it accounts for one-third of all
deaths in the world (Us ha et al ., 2010). The discovery of
antibiotics was an essential part of combating bacterial
infections that once ravaged humankind (Usha et al., 2010).
Antibiotics are critical weapons in combating bacterial
infections and can be beneficial for human health (Berge and
Wierup, 2012). However, overtime, the effect of antibiotics
that routinely used have decreased against certain infections
due to production of toxic reactions and the development of
resistant strains of bacteria (DiMasi et al, 2016). The rapi d
development of drug-resistant bacteria is an important health
problem that occurred worldwide (Rouveix, 2007 and
Ahmed, 2013). The alarming growth of the number of
antibiotic resistant bacteria and difficulties in treatment of
infections, besides sometim es antibiotics use may cause
opposite effects, such as allergic reactions, immune
destruction, and hypersensitivity have initiated a search for
new antibacterial compounds and develop new alternative
strategies in combating bacterial infections (Agrawal et al.,
1996). Medicinal plants, with their long history of use in folk
medicine for the treatment of infectious diseases, have
become a promising innovative antimicrobial substances by
extraction of phytochemicals, which are active to prevent
infections (Abiramasundari et al., 2011 and Agrawal et al.,
1996). Plant -derived compounds could exhibit a direct
* Corresponding author
This is an open access under a CC BY -NC-SA 4.0 license ( -nc-sa/4.0/)
antibacterial activity and/or an indirect activity as antibiotic
resistance modifying compounds, which, combined with
antibiotics, increase their effectiveness (Haroun and Al -Kayali,
The use of plant extracts can be highly significant in therapeutic
treatments and there are many different medicinal plants used in
traditional medicine by the traditional herbalists to treat varieties
of human ailments (Aali et al., 2018). Numbers of different plants
have been used due to their antimicrobial activity as a result of
their active substances while others by a combination of their
common phytochemicals with antibiotics (Ahmed et al., 2010).
For this reason, the antibacterial activities of plant extract alone
and when it combined with different antibiotics have been
studied in many parts of the world by a number of researchers.
Farooqui et al . (2015) investigated synergistic antimicrobial
activity of Camellia sinensis and Juglans regia with nalidixic acid
against 350 Gram-positive and Gram-negative strains belonging
to 10 different bacterial species. While Liu et al. (2017) studied
synergistic antimicrobial effect of lipopeptides and tea
polyphenols against V. parahaemolyticus and their result showed
that the combination of lipopeptides and tea polyphenols
displayed strong synergistic antibacterial effect against V.
parahaemolyticus with a fractional inhibitory concentration
index of 0.19. In another study by Ennacerie et al . (2017) also
tested the antibacterial potency and evaluate the possible
synergistic effect between both aqueous and ethanolic extracts,
flower buds and fruits of Capparis spinosa , and antibiotics
against Klebsiella pneumoniae and Pseudomonas aeruginosa
and their results showed a synergistic effect with ICIF ranging
from 0.02 to 0.24. From the points of view, the present study
S.A. Shareef et al. / Science Journal of University of Zakho 8(1), 7-11, March-2020
conducted to investigate whether the combination of some
plant extracts with commonly used antibiotics has any
synergistic effects on some clinically isolated bacteria or not.
2. 1. Plant materials and extraction
Henna (Lawsonia inermis) leaves, pomegranate (Punica
granatum) peel, Peanut (Arachis hypogaea) and Sesame
(Sesamum indicum) were selected as medicinal plants for
The plant materials were processed by the methods described
previously by (Harborne, 1998). Briefly, pulverized plant
material (after cleaning and shade drying) was extracted
using normal hexane, methanol, and ethanol as solvents. To
remove the solvents from the extracts vacuum evaporator
was used to attain the crude extract of each fraction. The
extracts stored at -20 ºC and freshly dissolved in dimethyl
sulfoxide (DMSO, Merk Germany) before use.
2.1.1. Extraction of henna leaf: Fifty grams of henna leaves
were dried under shade, milled and extracted with n-hexane
by the use of Soxhlet extractor apparatus for about six hours.
Extraction was carried out the color of the solvent in the last
siphoning time became colorless. Then, the solvent
evaporated under reduced pressure by the use of a rotary
evaporator apparatus. The marc obtained from henna was
shade dried and re-extracted with methanol using the above
2.1.2. Extraction of Pomegranate Peel: Fifty grams of
Pomegranate dry powder was mixed with ethanol, sonicated,
and filtered by Whatman paper no.1. The supernatant was
dried by rotary evaporator.
2.1.3. Volatile oil of sesame and peanut: One hundred
grams of both sesame and peanut weighted were put in 2000
ml rounded bottom capacity flask, separately. Both
Clevenger receiver and condenser were attached to the top of
the flask, 1000 ml of distilled water was added. The system
was heated to 100◦C for about 4h until the oil volume at the
upper part of the receiver fixed. The oil was pipetted and
dried over sodium sulfate anhydrous. Then, it was stored in a
dark container in the refrigerator till used (Harborne, 1998).
2.2. Preparing of oil concentrations
Each plants extract was dissolved in dimethyl sulfoxide
(DMSO) (50% of the final volume) and was then diluted with
Tryptic Soy Broth medium (TSB; Oxoid) to concentrations
(2, 4, 8, 16, 32, 64, 128) mg/ml.
2.3. Antimicrobials
Pure antimicrobial powders of Ciprofloxacin and
Erythromycin were selected as antimicrobials in this study.
The stock solution was prepared by dissolving the powder in
TSB in different concentrations (2, 4, 8, 16, 32, 64, 128)
mg/ml (Lalitha, 2004).
2.4. Bacterial isolates
Clinical isolates investigated in this study were;
Acinetobacter baumannii and Pseudomonas aeruginosa as
Gram-negative, Bacillus cereus and Staphylococcus aureus
as Gram-positive (The isolates were obtained from
Bacteriology laboratory of West Emergency Hospital in Erbil
City. Vitek II automated system (bioMérieux Marcy
l’´Etoile, France) (Vitek Systems Version: 06.01) was used
to identify the isolates.
2.5. Minimum inhibitory concentration (MIC) determination
Broth microdilution assay was performed to determine the
minimum inhibitory concentration for the galls extracts against
the identified isolates (Roberts et al., 2012). Ten µl of bacterial
cells (equilibrated to OD550 0.5) inoculated into 100µL TSB
containing a range of extracts or antimicrobials concentrations
beginning (1-128 mg ml-1) in the polystyrene microtiter plate
(MTP) wells. The MTPs have incubated overnight at 37 ºC. The
lowest concentration that did not show any obvious growth was
considered as minimum inhibitory concentration. To determine
the minimum bactericidal concentration, 100 µl from MTP wells
that did not show any obvious growth was streaked on sterile
plates of nutrient agar (NA; Oxoid). Nutrient agar (NA) plates
were incubated overnight at 37 ºC. Concentrations that have no
growth on NA plates were considered as minimum bactericidal
concentration (MBC). The level below the MICs was considered
as subinhibitory concentrations (SICs) which then used to
evaluate the synergistic effect of the extracts with antimicrobials.
Three replicates were considered on distinct occasions.
2.6. Checkerboard technique to determine the synergistic
antimicrobial activity
To investigate the effect of the combination of each extract with
the selected antimicrobials 150 μL of TSB medium containing a
mixture of SIC of each plant extract and each of the tested
antimicrobials were added to 96-well microtiter plates, TSB with
no extract and antimicrobials was used as a control. The wells
were inoculated with 10 μL of a bacterial suspension. All
experiments were achieved in triplicate, and the MTP was
incubated overnight at 37ºC. To determine the synergistic effect
of the extracts and the antimicrobials the broth in the wells were
sub-cultured on NA plates.
The combination between the extracts and the antibiotics were
evaluated by the checkerboard method as described by Petersen
et al (2006). The fractional inhibitory concentration (FIC) was
derived from the lowest concentrations of the extract in tryptic
soy broth tube after overnight incubation at 37 °C. FICs were
calculated using the following formula:
When antibiotic combined with a plant extract, synergy is
happened when FIC index ≤ 0.5, additivity when 5 < index FIC
≤ 1, indifference when 1< FIC index ≤ 4 and antagonism when
FIC index > 4 as described by Petersen et al. (2006). While
Kamatou et al (2006) defined synergy that happened when FIC
index<1.0, additivity when FIC index=1.0 and antagonism when
FIC index > 1.0. Hence, due to checkerboard assay, Olajuyigbe
and Afolayan (2012) indicated that synergy is determined when
FIC is less than or equal to 0.5 or is less than or equal to 1.
2.7. Statistical data analysis
All the data were analyzed by Statistical Package Social Science
(SPSS) version 21.0. The experimental results were expressed as
mean ± standard error of the mean (SEM). Groups were
compared by analysis of variance using Two-way ANOVA and
Dunnett's multiple comparisons test. Less than 0.05 of p-value
was regarded as statistically significant. Significance was defined
as p<0.05, p<0.01.
S.A. Shareef et al. / Science Journal of University of Zakho 8(1), 7-11, March-2020
The Minimum inhibitory concentration (MIC) of plant
extracts alone, and antibiotics alone were examined against
tested bacteria, as shown in Table (1), Figure (1).
Ciprofloxacin showed inhibited active on bacterial species at
(4 mg/ml) against all tested bacteria while erythromycin was
more active and inhibited tested bacteria at 1 mg/ml except
S. aureus (2 mg/ml).
The antibacterial activities of the plant extract varied in
relation to the tested organisms. Henna extract was the most
effective against all tested bacteria. The most active
concentration was 4 mg/ml concentration that inhibited the
growth of Staphylococcus aureus, Acinetobacter baumannii
and Bacillus cereus utterly, while Pseudomonas aeruginosa
was inhibited by 8 mg/ml concentration of henna extract.
Pomegranate also showed antibacterial activity with different
concentrations against all tested bacteria. Most effective
concentration was 4 mg/ml against P. aeruginosa, 16 mg/ml
against Acinetobacter while S. aureus and B. cereus were
inhibited at a minimum inhibitory concentration of 32 mg/ml.
Peanut showed similar effects to that of henna against P.
aeruginosa at MIC of 8 mg/ml and A. baumannii at MIC of
4 mg/ml, while it was less effective against B. cereus at MIC
of 32 mg/ml.
Table 1. Minimum inhibitory concentration (MIC) of plant extracts
alone and antibiotics alone against tested bacteria
Antibiotic and
Plant extract
MIC (mg/ml)
(Lawsonia inermis)
(Punica granatum)
(Arachis hypogaea)
(Sesamum indicum)
Figure 1. Minimum inhibitory concentration (MIC) of plant extracts
alone and antibiotics alone against tested
In vitro interaction between antimicrobials and tested plant
extracts by microdilution method showed a reduction of MIC
of the antimicrobials when combined with plant extracts. The
minimum inhibitory concentration of antibiotics in
combination with plant extracts against pathogenic bacteria
tested by microdilution method is shown in Table [2].
Table 2. Minimum inhibitory concentration of antibiotics in
combination with plant extracts against tested bacteria using the
microdilution method
Antibiotic and
Plant extract
MIC (mg/ml)
S. aureus
Cip + Sesame
Cip + Henna
Cip +
Cip + Peanut
Ery + Sesame
Ery + Henna
Ery +
Ery + Peanut
N= No effect
Antibacterial combination considered as synergism in ∑FIC ≤
1.0, indifference in 1.0 < ∑FIC ≤ 4 and antagonism in ∑FIC > 4
[Table 3]. According to the standard evaluation measures of
Kamatou et al. (2006) and Grytten et al. (1988). In combination
between ciprofloxacin and henna leaf extract, the MIC of
ciprofloxacin was reduced from 4 mg/ml to 2 mg/ml and showed
synergistic interaction against P. aeruginosa and Acinetobacter
(∑FIC is less than or equal to 1.0), while it was indifference (1.0
< ∑FIC ≤ 4) against B. cereus. The MIC of henna leaf extract was
decreased from 4, 8, 4 mg/ ml to 2, 4, 2 mg/ ml against B. cereus,
P. aeruginosa and Acinetobacter respectively. The combination
interaction between ciprofloxacin with pomegranate (against P.
aeruginosa and Acinetobacter) and peanut (against B. cereus)
showed a significant reduction of MIC for both antibiotic and
plant extract and the combination was classified as synergy
(∑FIC ≤ 1.0). Erythromycin and sesame activity against S.
aureus and B. cereus also were more effective when combined
together and reduced the MIC against these bacteria while no
synergistic effect of them was produced against the other tested
bacteria. No significant reduction of MIC occurred in
combination between erythromycin and both henna and
pomegranate, while there was a synergistic effect of the
combination of erythromycin and peanut and the MICs of both
of them decreased against B. cereus.
Table 3. Fractional inhibitory concentrations (FIC) of different
combination of the extracts and the antibiotics.
and Plant
Fractional Inhibitory Concentration
FIC index
Cip + Henna
B. cereus
Cip + Henna
P. aeruginosa
Cip + Henna
A. baumannii
Cip + Peanut
B. cereus
P. aeruginosa
A. baumannii
Cip + Sesame
S. aureus
Ery + Peanut
B. cereus
Ery + Sesame
S. aureus
Ery + Sesame
B. cereus
Cip= Ciprofloxacin, Ery = Erythromycin
S.A. Shareef et al. / Science Journal of University of Zakho 8(1), 7-11, March-2020
Many studies have been reported, assuring the antimicrobial
activities of an individual or combined extracts of medicinal
plants. In this study, henna extract was more effective against
all tested bacteria than the other plant extracts. Henna has
many traditional and commercial uses, the most common
being as a dye for hair, skin and fingernails because it
contains Lawsone (2-hydroxynaphthoquinone) which is one
of the component with (0.5-1.5%) responsible for dyeing. It
also contains tannic acid, mucilage, gallic acid and mannite
(Kelmanson et al., 2000). The antimicrobial effect of henna
may be according to numerous free hydroxyls which are able
to combine with the bacterial cell wall structures including
carbohydrates and proteins as suggested by Harborne and
Baxter (1995) and they attributed that to their attachment to
enzyme site rendering them inactive.
Results of the present study showed that pomegranate peel
extract was effective against tested bacteria. In particular,
among plants, Punica granatum used in traditional medicine,
is known for its pharmacological properties that have been
evaluated due to antiparasitic, antibacterial, antifungal,
antiproliferative, apoptotic, and anticancer effects (Jurenka,
2008). Literature data reported that extracts of Punica
granatum peel in different concentrations were effective
against different bacterial species such as S. aureus, E.
coli, Salmonella enterica, Shigella sonnei, Enterococcus
faecalis, and Bacillus subtilis (Pagliarulo et al., 2016;
Subramaniam et al, 2012; Rosas-Burgos et al, 2017 and Dey
et al, 2015). Pomegranate beverage contains several
compounds that are responsible for the antimicrobial activity,
depending on their abundance such as tannins which are
considered to be toxic to microorganisms (Viuda-Martos et
al., 2010). Their hydrophilic site cooperates with the polar
region of the bacterial cell membrane, while the hydrophobic
site is immersed in the non-polar region of the bacterial
membrane, this affects transporting of substances into the cell
(Cristani et al., 2007). Likewise, Naz et al. (2007) suggested
a phenolic toxicity through reactions with sulfhydryl groups
or through more non-specific interactions with proteins
leading to loss of function.
Sometimes the use of antibiotic alone does not give the
desired inhibitory effects, this can be defeated by a
combination of drugs which appears their synergistic effect,
and this is more significant than their effects alone (Kamatou
et al, 2006). Synergism is defined as a positive interaction
created when two agents are combined and together they
exert an inhibitory effect (on the targeted organisms) that is
greater than the sum of their individual effects (Levinson and
Jawetz, 2002). Consequently, mixing plant extracts with
antibiotics enhanced and synergized their effect and
decreased their MICs and this fact has clearly emerged in this
study. The synergistic effect could be related to the formation
of complex chemical products that can be greatly effective to
inhibit many species of microorganisms by preventing cell
wall to synthesize or may lead to lyses and finally, it dies
(Chanda and Rakholiya, 2011). There was a significant
synergistic effect of combination between both ciprofloxacin
and erythromycin with henna, sesame, pomegranate, and
peanut and the MIC of both of them was decreased against
tested bacteria and this could be referred to that these crude
extracts have many different phytochemicals which might
inhibit bacteria by different mechanisms (Duke et al., 2003).
This result reveals that plant extracts were potentiating the
effects of the ciprofloxacin and erythromycin. This double
attack of both agents on different target sites of the
bacteria could theoretically lead to either an additive or a
synergistic effect (Esimone et al. 2006). In a previous
similar study performed by Sato et al (2004), they were
combined between methanolic extract of pomegranate and
antibiotics and found that the antimicrobial activity of flavonoids
and polyphenols when they combined with antibiotics could alter
the bacterial resistant properties to be more effective. Cushnie et
al (2005) in different study indicated synergism between
antibiotics and flavonoids. Tsuchiya et al (1996) reported that
flavonoids disrupt bacterial cell membranes while Prasad et al
(2008) found that tannins precipitate bacterial protein. Yang et
al. (2005) and Aqil et al. (2005) reported in a previous in vitro
studies, significant decreasing in the MICs and synergistic effects
of the antibiotics when combined with number of plant extracts
against Staphylococcus aureus.
Ciprofloxacin is a second generation fluoroquinolone, interrupts
DNA replication by inhibiting both topoisomerase II (an enzyme
that reduces the amount of supercoiling of the DNA double-
stranded helix during the replication process) and IV thus
preventing cell division (Grohe et al, 1987). By the way, Liu et
al. (2011) stated that flavonoids are exist in many types of our
food such as vegetables, and fruits and they are able to combine
with fluoroquinolone antibiotics to exhibit an effective
antimicrobial agent.
Obtained results confirm the antibacterial activity of henna,
pomegranate, peanut and sesame extract and shows their
potential use as agents which enhance antibiotic activity.
Sometimes mixing plant extracts with different antimicrobials
enhanced and increase their antibacterial activity and the
antimicrobials that produce side effects can be used by reducing
dose concentration exploiting their synergy with the medicinal
plants. Mixing plant extracts with antimicrobials also increases
the spectrum of antibiotic, avoids the development of resistance
and decreases toxicity so exhibiting antibacterial activity better
than that estimated from each antibiotic alone. Further studies are
required to determine the specific substrates that have synergistic
effect and approved with in vivo studies.
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... In this study, antimicrobials such as tetracycline and sulfonamide were tested as pure powders. Dissolving the powder in TSB at various concentrations (0.5, 2, 4, and 8 mg/ml) yielded the stock solution [14] . ...
... The wells were then filled with the various concentrations of plant extract (0.5, 2,4 and 8 mg/ml) (18 hours). After 24 hours of incubation, the area of inhibition (measured in mm) [14] . ...
... In addition, the combination may be helpful in the preclusion of the emergence of resistant bacteria and reducing the drug toxicity 27 . Various in vitro experiments have established the fact that a combination of plant extracts and antibiotics possess a synergistic effect, which results in a significant decrease in levels of minimum inhibitory concentration for the antibiotics 28,29 . ...
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Worldwide, the use of antibiotics is losing effectiveness due to the substantial resistance to the antimicrobial developed by many pathogenic bacteria. African populations including Rwanda, use frequently traditional medicine for primary care. This study aimed to determine the phytochemicals and the antimicrobial activity of Ocimum. suave (O. suave) against selected human pathogenic bacteria (two strains of S. aureus, P. aeruginosa, two strains of E. coli, S. pneumonia, S. pyogene, K. oxytoca, H. influenza, S. sonei). The leaf and stem extracts were prepared using maceration technique. The antimicrobial activities of extracts were evaluated using the impregnated disc and agar well diffusion methods. The tests revealed the presence of phytochemical substances such as tannins, flavonoids, saponins, steroids alkaloids and phenolics in leaves and only saponins in stem. S. aureus ATCC 43300 was the most sensitive while H. influenza was the most resistant among the microorganisms tested. Aqueous and methanolic crude extract of O. suave displayed maximum diameter of inhibition zone against bacteria (9-26.5 mm and 9-23.5 respectively) and Two-way ANOVA showed statistical significance difference between their means. T-test was used in comparison with standards antibiotics and showed that the distilled water extracts exhibited much higher activity against all tested organisms than activity of streptomycin. Combination of distilled water and methanol extracts with streptomycin revealed synergistic activity against E. coli ATCC 25922 and S. pneumonia ATCC 49618. The leaves of O. suave have a great potential antibacterial activity and should be fully explored for future treatment. Keywords: phytochemical; antimicrobial activity; Ocimum suave, Rwanda
... 19 Shareef et al studied the synergistic effect of methanol extract Lawsonia inermis, ethanol extract of Punica granatum, the volatile oil of Sesamum indicum, and Arachis hypogaea against Gram-positive and Gram-negative bacteria. 20 The interaction between the methanol extract of Ziziphus mucronata and antibiotics against bacteria enhanced the antibacterial activity. 21 One of the studies of Wess et al reported that a combination of four drugs (axitinib, erlotinib, dasatinib, and AZD4547) was significantly more potent for cancer treatment than monotherapies of all single drugs. ...
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Introduction: Synergy is defined as an interaction of some substances that cooperate to give rise to the combined effect greater than the sum of their individual effects. It is a natural strategy that has evolved by nature to more efficacy with low cost. Methods: This study is designed to evaluate the chemopreventive effect of a combined drug sample which is prepared by mixing an equal portion of stigmasterol and palmatine isolated from Azadirachta indica and Tinospora cordifolia respectively at a concentration of 100 mg/kg and 200 mg/kg body weight during the whole concentration. Results: At the end of the study, it was found that this combined drug sample decreased the number of tumors and their size. This drug significantly reduced the serum level of glutamate pyruvate transaminase, alkaline phosphatase, glutamate oxalate transaminase, and bilirubin and enhanced the level of oxidative enzyme level of glutathione, superoxide dismutase, and catalase, and inhibit the level of lipid peroxides. Discussion: The result suggests that combined drug samples exhibit a chemopreventive effect which is better than the effect of individual drugs (stigmasterol and palmatine).
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Objective(s) To evaluate the in vitro interaction between different extracts of Thymbra spicata L. and certain antimicrobial drugs of different mechanisms, including ampicillin, cefotaxime, amikacin and ciprofloxacin. This study was performed against multidrug-resistant strains of Staphylococcus aureus and Klebsiella pneumoniae. Materials and Methods Evaluation of antibacterial activity and synergy interaction between plant extracts and antimicrobial agents was carried out using checkerboard microdilution. Results Different interactions (synergistic, additive and indifference) were observed between plant crude extracts and used antibiotics depending on the strain. The fractional inhibitory concentration (FIC) index ranged from 0.02 to 1.5 for S. aureus and 0.25 to 2 for K. pneumoniae strains. The best synergistic capacity appeared with cefotaxime against S. aureus strains, where the activity of cefotaxime was increased from 8- to 128-fold. Conclusion These results may indicate that T. spicata extracts potentiates the antimicrobial action of antibiotics, suggesting a possible utilization of this herb in combination therapy against emerging multidrug-resistance S. aureus and K. pneumoniae.
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Antimicrobial drug resistance is a natural phenomena. It is exacerbated by under use and over use of antimicrobials. Microorganisms develop resistance by various mechanisms and resistant genes are incorporated to the organism and genetic transfer of resistance occurs. Infection caused by resistant microbes fails to respond to treatment and selection of resistant strains occurs.Veterinary antimicrobials also contribute to development of resistance in human. Antimicrobial drug residues after treatment of infectious diseases and with the use of antimicrobial growth promoters in animal pose greater risk of development of antimicrobial drug resistance in human beings. In order to prevent development of drug resistance proper withdrawal time for the food of animal origin should be followed. Removal selection pressure can cause reversion of resistant strains to susceptible. Indiscriminate use of antimicrobial agents should be avoided.
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Introduction: The aim of the present in vitro study was to evaluate and compare the antibacterial effect of pomegranate and aloe vera extracts on Streptococcus mutans. Materials and Methods: Hydroalcoholic extracts of pulp from both Punica granatum (pomegranate) and Aloe barbadensis miller (aloe vera) were prepared to concentrations of 5, 25, 50 and 100%. Pure sorbitol powder dissolved in distilled water was taken as the negative control. Streptococcus mutans (S mutans) was isolated from saliva by inoculation on to Mitus Salivarius Bacitracin (MSB) agar, which was then streaked onto agar plates containing Brain Heart Infusion. In each petridish, wells were prepared and using a sterile micropipette, 125l of the specific concentration of the extract (pomegranate/aloe vera/sorbitol) was deposited in each well. This was done in triplicate for each concentration of the extracts. The effect of different concentrations of the extracts on S mutans was observed and the data was subjected to statistical analysis. Results: Pomegranate extract showed significantly higher inhibitory effect on S mutans at all concentrations (P0.05). On comparison of all three extracts at different concentrations, a significant difference (P0.05) was observed only at 50 and 100% concentrations. The inhibitory effect of pomegranate extract was significantly different when compared to aloe vera and sorbitol extracts. (P0.01). Discussion: Pomegranate extract has a significant antibacterial effect on S mutans at all concentrations.
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Context: The global surge in multidrug-resistant bacteria and the imminence of tuberculosis pandemics necessitate alternative therapeutic approaches to augment the existing medications. Pomegranate, the fruit of Punica granatum Linn. (Punicaceae), widely recognized for potency against a broad spectrum of bacterial pathogens, deserve further investigation in this respect. Objective: This study determines the therapeutic potential of pomegranate juice as well as non-edible parts of the fruit, and its four polyphenolic constituents, namely, caffeic acid, ellagic acid, epigallocatechin-3-gallate (EGCG) and quercetin, against drug-resistant clinical isolates. Materials and methods: Phenotypic characterisation of Mycobacterium tuberculosis, extended-spectrum β-lactamase (ESBL) and KPC-type carbapenemase producing Klebsiella pneumoniae was performed by biochemical and molecular methods. Resistance profiles of M. tuberculosis and K. pneumoniae were determined using LJ proportion and Kirby – Bauer methods, respectively. Pomegranate juice, and the peel extract prepared with methanol / water, and four pure compounds were evaluated by broth micro-dilution method to determine minimum inhibitory and bactericidal concentrations (MIC and MBC) against the drug-resistant isolates and their representative ATCC strains. Results: The peel extracts exhibited greater antimycobacterial activity (MIC 64 – 1024 μg/mL) than the potable juice (MIC 256 – >1024 μg/mL). EGCG and quercetin exhibited higher antitubercular (MIC 32 – 256 μg/mL) and antibacterial (MIC 64 – 256 μg/mL) potency than caffeic acid and ellagic acid (MIC 64 – 512 μg/mL). Discussion and conclusion: The pomegranate fruit peel and pure constituents were active against a broad panel of M. tuberculosis and β-lactamase producing K. pneumoniae isolates. EGCG and quercetin need further investigation for prospective application against respiratory infections
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Synergistic combinations of antimicrobial agents with different mechanisms of action have been introduced as more successful strategies to combat infections involving multidrug resistant (MDR) bacteria. In this study, we investigated synergistic antimicrobial activity of Camellia sinensis and Juglans regia which are commonly used plants with different antimicrobial agents. Antimicrobial susceptibility of 350 Gram-positive and Gram-negative strains belonging to 10 different bacterial species, was tested against Camellia sinensis and Juglans regia extracts. Minimum inhibitory concentrations (MICs) were determined by agar dilution and microbroth dilution assays. Plant extracts were tested for synergistic antimicrobial activity with different antimicrobial agents by checkerboard titration, Etest/agar incorporation assays, and time kill kinetics. Extract treated and untreated bacteria were subjected to transmission electron microscopy to see the effect on bacterial cell morphology. Camellia sinensis extract showed higher antibacterial activity against MDR S. Typhi, alone and in combination with nalidixic acid, than to susceptible isolates." We further explore anti-staphylococcal activity of Juglans regia that lead to the changes in bacterial cell morphology indicating the cell wall of Gram-positive bacteria as possible target of action. The synergistic combination of Juglans regia and oxacillin reverted oxacillin resistance of methicillin resistant Staphylococcus aureus (MRSA) strains in vitro. This study provides novel information about antimicrobial and synergistic activity of Camellia sinensis and Juglans regia against MDR pathogens.
The research and development costs of 106 randomly selected new drugs were obtained from a survey of 10 pharmaceutical firms. These data were used to estimate the average pre-tax cost of new drug and biologics development. The costs of compounds abandoned during testing were linked to the costs of compounds that obtained marketing approval. The estimated average out-of-pocket cost per approved new compound is $1,395 million (2013 dollars). Capitalizing out-of-pocket costs to the point of marketing approval at a real discount rate of 10.5% yields a total pre-approval cost estimate of $2,588 million (2013 dollars). When compared to the results of the previous study in this series, total capitalized costs were shown to have increased at an annual rate of 8.5% above general price inflation. Adding an estimate of post-approval R&D costs increases the cost estimate to $2,870 million (2013 dollars).