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Antifungal activity of different neem leaf extracts and the nimonol against some important human pathogens

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This study was conducted to evaluate the effect of aqueous, ethanolic and ethyl acetate extracts from neem leaves on growth of some human pathogens (Aspergillus flavus, Aspergillus fumigatus, Aspergillus niger, Aspergillus terreus, Candida albicans and Microsporum gypseum) in vitro. Different concentrations (5, 10, 15 and 20%) prepared from these extracts inhibited the growth of the test pathogens and the effect gradually increased with concentration. The 20% ethyl acetate extract gave the strongest inhibition compared with the activity obtained by the same concentration of the other extracts. High Performance Liquid Chromatography (HPLC) analysis of ethyl acetate extract showed the presence of a main component (nimonol) which was purified and chemically confirmed by Nuclear Magnetic Resonance (NMR) spectroscopic analysis. The 20% ethyl acetate extract lost a part of its antifungal effect after pooling out the nimonol and this loss in activity was variable on test pathogens. The purified nimonol as a separate compound did not show any antifungal activity when assayed against all the six fungal pathogens.
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1007
Brazilian Journal of Microbiology (2011) 42: 1007-1016
ISSN 1517-8382
ANTIFUNGAL ACTIVITY OF DIFFERENT NEEM LEAF EXTRACTS AND THE NIMONOL AGAINST SOME
IMPORTANT
HUMAN PATHOGENS
Mahmoud, D.A.*;Hassanein, N.M.; Youssef, K.A.; Abou Zeid, M.A.
Department of Microbiology, Faculty of science, Ain-Shams University, 11566, Abbassia, Cairo, Egypt.
Submitted: May 22, 2010; Returned to authors for corrections: August 23, 2010; Approved: January 13, 2011.
ABSTRACT
This study was conducted to evaluate the effect of aqueous, ethanolic and ethyl acetate extracts from neem
leaves on growth of some human pathogens (Aspergillus flavus, Aspergillus fumigatus, Aspergillus niger,
Aspergillus terreus, Candida albicans and Microsporum gypseum) in vitro. Different concentrations (5, 10,
15 and 20%) prepared from these extracts inhibited the growth of the test pathogens and the effect gradually
increased with concentration. The 20% ethyl acetate extract gave the strongest inhibition compared with the
activity obtained by the same concentration of the other extracts. High Performance Liquid Chromatography
(HPLC) analysis of ethyl acetate extract showed the presence of a main component (nimonol) which was
purified and chemically confirmed by Nuclear Magnetic Resonance (NMR) spectroscopic analysis. The 20%
ethyl acetate extract lost a part of its antifungal effect after pooling out the nimonol and this loss in activity
was variable on test pathogens. The purified nimonol as a separate compound did not show any antifungal
activity when assayed against all the six fungal pathogens.
Key words: Azadirachta indica, Aqueous and organic extracts, HPLC, Fungal inhibitory effect
INTRODUCTION
Neem (Azadirachta indica) tree has attracted worldwide
prominence owing to its wide range of medicinal properties.
Neem leaf and its constituents have been demonstrated to
exhibit immunomodulatory, anti-inflammatory,
antihyperglycaemic, antiulcer, antimalarial, antifungal,
antibacterial, antioxidant, antimutagenic and anticarcinogenic
properties (26).
Leaf and seed extracts of A. indica were tested for
antidermatophytic activity and found effective against some
dermatophytes such as Trichophyton rubrum, T. violaceaum,
Microsporum nanum and Epidermophyton floccosum by the
tube dilution technique (16) and on C. albicans (17).
The minimum inhibitory concentration (MIC) and
minimum fungicidal concentration (MFC) for extracts from
leaves and seeds of neem were evaluated (17) against various
dermatophytes. The authors found that changes in the growth
curve of the treated dermatophytes were statistically significant
with reference to the untreated fungi. The MIC of extracts from
neem leaves and seeds were 31 and 15 µg/ml, respectively and
which was sufficient to destroy Trichophyton rubrum, T.
*Corresponding Author. Mailing address: Department of Microbiology, Faculty of Science, University of Ain Shams, Elkhalifa Elmamoun street,
11566,Abbassia, Cairo,Egypt.; Tel.: +20103887237, Fax: +20226842123.; E-mail: drdaliaali@yahoo.com
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Mahmoud, D.A. et al. Neem leaf extracts against human pathogens
mentagrophytes and Microsporum nanum.
Neem seed oil is used to treat certain chronic skin
diseases, ulcers, different types of metritis, leprosy, gum and
dental troubles and the seed oil is said to be non-mutagenic.
However, neem seed oil is toxigenic when given orally and
further studies might throw light on the systemic toxicity of the
solvent extracts of the neem seed (3).
Neem elaborates a vast array of biologically active
compounds that are chemically diverse and structurally
variable with more than 140 compounds isolated from different
parts of the tree (26). Quercetin and ß-sitosterol, were the first
polyphenolic flavonoids purified from neem fresh leaves and
were known to have antibacterial and antifungal properties (9).
The same authors purified the active fractions of neem organic
extracts using HPLC and found that their content of major
compounds such as 6-deacetylnimbin, azadiradione, nimbin,
salannin and epoxy-azadiradione were with appreciable active
when bioassayed on many pathogenic fungi (9). Trish et al.
(28) determined the chemopreventive potential of A. indica leaf
extract in murine carcinogenesis model system of 7-week-old
Swiss albino mice and reported that tumor incidence was
reduced by doses of neem leaf extract. The results revealed that
the Indian neem tree contained at least 35 biologically active
principles.
The present investigation aimed to (1) compare the
antifungal activity of aqueous and organic (ethanole and ethyl
acetate) extracts from neem leaves against six important human
pathogens (A. flavus, A. fumigatus, A. niger, A. terreus, C.
albicans and M. gypseum); (2) to analyze the contents of the
most active extract using HPLC and determine the antifungal
activity of the main component against the same test
pathogens.
MATERIALS AND METHODS
Neem leaves
Neem leaves (Azadirachta indica A. Juss) were collected
from 10-12 years old trees from Kalyoub Administry of
Agriculture, Kalyoub city, Egypt.
Pathogenic fungi
The test fungal pathogens (Aspergillus flavus, A.
fumigatus, A. niger, A. terreus, Candida albicans and
Microsporum gypseum) were obtained from the
Microbiological Resource Center (MIRCEN), Faculty of
Agriculture, Ain Shams University, Cairo, Egypt.
Preparation of different leaf extracts
The preparation of aqueous neem leaf extract was carried
out according to the method described by (23). Whereas
organic extracts were prepared following the method of (19).
Antifungal activity of different extracts of neem leaves
The antifungal effect of aqueous and organic extracts of
neem leaves was assessed by measuring radial growth of the
test pathogens following the technique described by (5).
HPLC analyses and chromatographic purification of
nimonol
Analysis of different components present in the mother
organic extract in ethyl acetate obtained from neem leaves was
performed according to the method (8). The organic extract
was fractionated by HPLC apparatus (Perkin-Elmer, Norwalk,
CT, USA) consisted of the following: A 410 LC pump
equipped with a LC 90 UV spectrophotometric detector and a
LCI 100 integrator at 230 nm using acherey-nagel 100 C-18
columns (20 mm x 25 cm, 215 nm). The mobile phase included
methanol (Carlo Erba, Milan, Italy) and Ultra pure water
purified in a Milli-Q system (Millipore, Bedford, MA, USA).
The chromatographic run which lasted for 2 h was carried out
for samples (20 µl for each) containing 3 mg EtoAc extract
dissolved in 1 ml methanol at a flow rate of 20 ml/min through
a stepwise gradient solvents in the following order: methanol :
water (70:30) for 40 minutes; methanol : water (80: 20) for
another 40 minutes and finally methanol : water (90: 10%) for
20 min before a final column wash after run completion with
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Mahmoud, D.A. et al. Neem leaf extracts against human pathogens
methanol in order to remove the non-polar components. Three
successive injections were carried out for the neem leaf organic
extract and for pure authentic samples of the following:
azadirachtins (Sigma-Aldrich (St. Louis, MO, USA). The main
component contained in peak no. 7 was separated at 63 min. by
HPLC for spectroscopic analyses (
1
H- and
13
C-NMR).
Spectral analysis of nimonol
A solution of nimonol (2.5 mg) in pyridine (0.25 ml) and
Ac
2
O (0.25 ml) was kept at room temperature for 24 hours. A
chromatographic purification using analytical silica gel
chromatographic plates (Kieselgel 60, F
254
, Merck, Germany)
and elution was carried out using 10% EtoAc in n-hexane.
NMR spectral analysis
1
H-NMR and
13
C-NMR spectral analyses were recorded in
CD3OD at 200 and 400 MHz on Bruker Spectrometeres using
the same solvent as internal standard. Chemical shifts are given
at value while coupling constants (J) are in Hz, carbon
multiplicities were determined by distortion enhancement by
polarization transfer “DEPT”.
Antifungal activity of nimonol
The purified nimonol was tested for antifungal activity
against all tested pathogens in comparison to the following:
mother organic extract in ethyl acetate 20% (A), (A) free from
nimonol (B) as described by (5).
Statistical analysis
The data were analyzed by using a completely randomized
factorial design (21). Significant differences between treatment
means were determined using Costal Program. Biological
results were analyzed by One Way ANOVA.
RESULTS
Activity of different neem leaf extracts against some human
pathogenic fungi
In general, two of the tested Aspergelli (A. flavus and A.
niger) were highly sensitive during assays whereas C. albicans
and M. gypseum were the weakest. The 20% concentration of
ethyl acetate extract gave the highest inhibition activity against
all test pathogens in all used concentrations compared with the
same concentrations from other extracts.
Activity of aqueous extract
The 5 % aqueous leaf extract of neem caused an inhibition
in growth of the six test fungal pathogens. The highest one
(35.22%) was recorded on A. niger while the lowest (4.00%),
was on C. albicans (fig.1-A). A concentration of 10%
moderately inhibited the growth of all test fungi with the
highest value (49.55%) recorded on A. niger and the lowest
(11.53 %) on C. albicans (fig.1-B). An inhibition by 86.22%
was recorded on the growth of A. niger compared with 38.44%
in the growth of M. gypseum (fig.1-C), when the neem leaf
aqueous extraxt was assayed at a concentration of 15%. These
ratios of inhibition jumped to 100 % and 53.66% in the growth
of A. niger and M. gypseum (fig.1-D) during the assay with the
20% concentration.
Activity of organic extracts
In assays using extracts in ethanol, the 5% concentration
gave 44.22% inhibition of A. flavus and 20.30% of C. albicans
(fig.1-A) whereas the 10% scored higher values recorded for A.
flavus (47.44%) and C. albicans (26.92%) (fig.1-B). By
increasing the extract concentration, the 15% (fig.1-C) and
20% (fig.1-D) highly suppressed the mycelia growth of all
tested pathogenic fungi.
When the antifungal activity was measured for all the six
fungal pathogens using the extracts in ethyl acetate, values of
inhibition in their growth significantly differed. The first
concentration (5%) affected A. flavus by 54.33% and C.
albicans by 9.84 % (fig.1-A). Fig.1-B is showing a marked
growth inhibition in growth of test fungi and the concentration
of 15% characteristically inhibited both A. flavus (91.11%) and
A. niger (88.50%), whereas M. gypseum was the least affected
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Mahmoud, D.A. et al. Neem leaf extracts against human pathogens
(64.88%) (fig.1-C). A maximum inhibition in growth which
reached 100% was recorded for the first time on two of the
pathogenic fungi (A. flavus and A. niger), when a concentration of
20% from the same organic extract was used (fig.1-D).
Figure 1. (A): Effect of different concentrations (5%) of aqueous (Aq.), ethanolic (Et.) and ethylacetate (EtoAc) leaf extracts of neem on growth
of pathogenic fungi on solid media. (B): Effect of different concentrations (10%) of aqueous (Aq.), ethanolic (Et.) and ethylacetate (EtoAc) leaf
extracts of neem on growth of pathogenic fungi on solid media. (C): Effect of different concentrations (15%) of aqueous (Aq.), ethanolic (Et.)
and ethylacetate (EtoAc) leaf extracts of neem on growth of pathogenic fungi on solid media. (D): Effect of different concentrations (20%) of
aqueous (Aq.), ethanolic (Et.) and ethylacetate (EtoAc) leaf extracts of neem on growth of pathogenic fungi on solid media.
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Mahmoud, D.A. et al. Neem leaf extracts against human pathogens
HPLC analyses and chromatographic separation of
nimonol
The HPLC diagram of the highly active organic extract
(A) showed ten well defined chromatographic peaks (Table 1
and Figure 3). These peaks were eluted at different retention
time (r
t
). The first peak was eluted after 9 min. and contained
three Azadirachtins (A, B, and C) at ratios of 7%, 5% and 8%,
respectively. The third peak was evident at r
t
of 22 min and
contained the azadirachtins A, B, D, H and I at ratios of 11%,
10%, 4%, 9%, and 7%, respectively. The 4
th
Peak was eluted
after 34 min and was identified as 6 de-acetyl nimbin of 39 %
purity. The peaks no. 2 and 5 (eluted at r
t
16 and 39 min,
respectively) yielded very small amounts of non-pure material
and were not enough for accurate identification. Peak no. 6 was
eluted at 54 min and contained mainly the azadiradione (51 %)
whereas at 63 min, peak no. 7 was eluted and contained the
nimonol with the highest purity level (82 %), followed by peak
no. 8 at 68.6 min which contained the epoxyazadiradione as a
major constituent (43 %). The last two peaks (9 and 10) were
eluted after 76 and 90 min, respectively and contained also
small amounts of non-pure materials especially the last one
which seems containing at least three components (Table 1).
Table 1. HPLC pattern of neem leaf ethylacetate (EtoAc) extract.
Band no. r
t
(min.) Total peak area etected (%) ID
Band 1 9 69.8% Azadirachtins: A (7%), B (5%), C (8%)
Band 2* 16 21.6% Not identified
Band 3 22 56.4 % Azadirachtins: A (11%), B (10%), D (4%),H (9%), I (7%)
Band 4 34 32.7% 6 De-acetyl nimbin (39%)
Band 5* 39 40.0% Not identified
Band 6 54 66.0% Azadiradione (51%)
Band 7 63 74.0% Nimonol (82%)
Band 8 68.6 30.0% Epoxyazadiradione (43%)
Band 9* 76 32.0% Not identified
Band10* 90 25.0% Not identified
Peaks analyzed by preparative HPLC using the same solvent system and found to be complex mixtures; quantities of pure material collected following their
purification were very small to be considered for further investigation.
Figure 3. High performance liquid chromatographic
pattern of neem leaf ethylacetate extract.
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Mahmoud, D.A. et al. Neem leaf extracts against human pathogens
Purification and spectral identification of nimonol
The used HPLC linear gradient solvent which consisted of
a mixture from methanol and water permitted the separation of
the pure compound contained in peak no. 7 and which was
subjected to NMR spectral analysis for the complete
identification.
The
1
H-NMR signals of nimonol were at 7.38 m; 7.26 m;
6.29 m (-substituted furan); 7.12 d, J= 10.06 Hz; 5.90 d, J=
10.06 Hz (-CH= CH-CO-); 5.42 dd, J = 1.82, 2.84 Hz (C= CH-
CH
2
), 2.05 (CH
3
CO). The
1
HNMR spectrum showed also three
methane protons at 2.21 d; J = 11.65 Hz (-CH-); 4.38 dd, J =
11.65Hz and 2.37 (-CHOH) and 5.35d, J= 2.37 Hz (-CHOAc-).
Coupling of the last three methane protons was recorded in
correlated spectroscopy (COSY) where the proton at 2.21 had
cross peaks with that at 4.38 whereas the proton at 4.38 had
cross peaks with those at 2.21, 5.31 in addition to the
proton at 5.36 with that at 4.38. The COSY spectrum also
showed the presence of the characteristic group –CH-CHOH-
CHOAc on a cyclohexane ring system.
The
13
C-NMR spectrum of nimonol revealed the presence of
an important signal which corresponds to the olefinic bond
between C-14 at 158.51 ppm and C-15 at 119.54 ppm and which
are characteristic for this class of compounds. The complete
1
H-
13
C-NMR spectral data are represented in (Table 2).
Table 2.
1
H and
13
C-NMR spectral data* of the purified nimonol
Detected
Protons
signal
J
(Hz) Detectedcarbons
H-1 7.12 d 10.06 C-1 157.63
H-2 5.9 d 10.06 C-2 126.33
H-5 2.21 d 11.68 C-3 204.98
H-6 4.38 d d 1.62,2.37 C-4 40.08
H-7 5.36 d 2.37 C-5 50.36
H-15 5.42 d d 1.82,2.84 C-6 68.42
H-17 2.83 d d C-7 78.83
H-21 7.26 M C-8 44.46
H-22 6.29 m C-9 38.09
H-23 7.39 m C-10 42.59
Oac 2.05 C-11 16.52
OH n.d. C-12 32.77
C-methyls 0.82 C-13 46.66
OAc 119.55
C-methyls 33.65
Chemical shifts are recorded in () values (ppm) in CDcl
3
and CD
3
OD , respectively.
Antifungal activity of nimonol
Data represented in Fig. 2 shows the antifungal activity of
the purified nimonol when tested separately against the six test
human pathogens. Results revealed that the pure nimonol alone
as a compound has no inhibitory effect on the growth of all test
fungi when assayed at concentration of 20%. Values recorded
indicates 2-3 times-higher inhibition values for the extract (A)
over that of (B) against the tested pathogens. For extract (B), it
was found that the inhibition percentages of the test pathogens
were lowered after pooling out nimonol (peak no. 7) from the
mother extract (A) at all concentrations. Values of inhibition
for the extract (A) when assayed at a concentration of 20%
showed the highest inhibition percentages against A. flavus
(55.28%) and M. gypseum (42.12%).
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Mahmoud, D.A. et al. Neem leaf extracts against human pathogens








Figure 2. Percentage of inhibition of different ethylacetate extracts (Aand B) and pure nimonol on the growth of pathogenic fungi.
DISCUSSION
Results obtained during assay with aqueous and organic
extracts from neem leaves showed their inhibitory effect at all
used concentrations against the sex pathogenic fungi. These
human pathogens included four Aspergillus species (A. niger,
A. flavus, A. terrues and A. fumigatus) which are known to
cause aspergilloses, in addition to Microsporum gypseum (a
dermatophyte) and Candida albicans, the causal agent of
dermatophytosis and candidiases. All concentrations of the
aqueous extract effectively suppressed the mycelial growth of
these fungi and this effect was found to increase with
concentration where a maximum activity was reached using the
last one (20%). These results are in agreement with Dube and
Tripathi (6) who showed that the aqueous extracts of A. indica
obtained from bark and leaf, inhibited both spore germination
and mycelial growth of Epidermophyton floccosum,
Microsporum canis and Trichophyton mentagrophytes. They
also found that this antifungal toxic effect was also retained in
organic extracts using ethanol. The 20 % aqueous neem leaf
extract had a toxic effect on 19 out of 22 tested moulds
including Aspergillus flavus (10).
Also, different types of extracts from neem leaves were
found to have inhibitory effect on Candida albicans (15).
The complete inhibition (100%) in the growth of A. niger
obtained in assay with 20% concentration of aqueous leaf
extract of neem agrees with the results of Bohra and Purohit(2)
who mentioned that the aqueous extracts of A. indica gave the
highest inhibition of A. flavus growth.
The inhibition in growth of the six test fungi by organic
extracts were higher than those recorded by the aqueous ones.
It was found that all concentrations of organic extracts (in
ethanol and ethyl acetate) effectively suppressed the mycelial
growth and the recorded values were increasing gradually with
concentration and reaching the highest ones with 20%. This
concentration gave 88.77% on A. flavus growth and 100% in
the growth of A. flavus and A. niger.
Khan et al. (12) reported that some leaf extracts including
those from neem had a characteristic effect on dermatophytes
especially for low polar extracts over the high polar ones. The
authors suggested that one possible explanation for this is the
flavonoid quercetin contained in the extracts. Shivpuri et al.
(24) noticed that the extracts in ethanol of A. indica had
fungitoxic properties against five pathogenic fungi when tested
under laboratory conditions at concentrations ranging between
500 and 1000 µg ml
-1
. The results obtained during assay with
organic extracts were also in accordance with those recorded
by Verma et al. (30) who found that a purified fraction (ethyl
acetate : chloroform, 3:1) of extracts in methanol from neem
seed coat showed strong antifungal activity against A. niger
and Curvularia lunata with MIC of 250 ppm. They found also
that the extracts in petroleum ether from the neem leaves were
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Mahmoud, D.A. et al. Neem leaf extracts against human pathogens
highly active at a lower MIC (100 ppm) against the same
pathogens. In recent study, Kishore et al. (13) reported that
ethanolic leaf extracts of A.indica inhibited the conidial
germination of Phaeoisariopsis personata by > 90% to control
late leaf spot of groundnut.
Upasana et al. (29) found that neem seed extract in
methanol was effective against Aspergillus niger, Fusarium
oxysporum and Trichoderma resii and that both dried and fresh
organic extracts from leaves were effective only against
Trichoderma resii.
Leaf extracts of neem were found to have a potent
antidermatophytic activity against Trichophyton rubrum, T.
violaceaum, Microsporum nanum and Epidrmophyton
floccosum (16). The same extracts were found to have
interesting inhibitory action on a wider spectrum of
microorganisms, including C. albicans, C. tropicalis, Neisseria
gonorrhea, multi-drug resistant Staphylococcus aureus, urinary
tract E. coli, Herpes simplex-2 and HIV with safety of the used
formulations and acceptability (26). The kill kinetics of A.
indica was determined by Okemo et al. (18) on different
pathogenic microorganisms including Staphylococcus aureus,
Escherichia coli, Pseudomonas aeruginosa and Candida
albicans. They concluded that the killing ability of A. indica
extracts is time and concentration dependent and cell wall
related.
Singh et al. (25) owed the fungicidal and bactericidal
properties of extracts from neem leaves either in vitro or in
vivo trials to the presence of several antimicrobial active
ingredients in leaves of neem tree such as desactylimbin,
quercetin and sitosterol. Whereas other researchers explained
this activity by the presence of active ingredients like
triterpenes or the limonoids such as meliantriol, azadirachtin,
desactylimpin, quercetin, sitosterol, nimbin, nimbinin,
nimbidin, nimbosterol and margisine (1) and/or to different
bitter substances such as alkaloids, phenols, resins, glycocides,
terpenes and gums (7, 11). Lyer and Williamson (14) attributed
antifungal properties of neem extracts to the inhibition in
protease activity of dermatophytes induced by the neem
organic extract.
The HPLC analysis of the most active organic extract (in
ethyl acetate) showed 4 peaks containing mainly the
triterpenoids, among these are the famous group of
Azadirachtins A, B, C, D, H, and I which don’t possess any
antifungal activity as proved by Govindachari et al. (8). A
similar analytical method was applied by Sharma et al. (22)
who purified three major constituents with only nematicidal
activity from the neem seed kernels on reversed phase
medium-pressure liquid chromatography and allowed to
separate the main component in a pure form which was
identified later by NMR spectroscopic techniques as nimonol.
1
H-NMR and
13
C-NMR showed characteristic signals of -
substituted furan and chemical shifts of an olefinic bond
between n C-14 and C-15 which confirm the chemical structure
of nimonol. The COSY spectrum also showed the presence of
the characteristic group (–CH-CHOH-CHOAc) on a cyclo
hexane ring system. Nimonol is a naturally occurring limonoid
(tetranortriterpinoid) with -methyl group at C-13 (27).
It was noticed that a loss (40-50%) occurs in the
antifungal activity for the four used concentrations of the
organic extract (in ethyl acetate) when the nimonol was pooled
even if this compound proved to be inactive against the test
fungi when separately assayed at the highest concentration
(20%). This reflects a possible potent synergism for the
different constituents present in this organic extract which is
together responsible for the characteristic antifungal activity
recorded during this study. This conclusion was illustrated in a
previous results by Govindachari et al. (9) who showed that a
mixture of fractions eluted from the HPLC was more effective
when assayed for antifungal activity than the purified
constituents. The authors attributed the lowering in antifungal
activity to an important fact that the triterpenoids when
purified, loose effect whereas in combination, an additive
synergism occurs between them and give the excellent activity
recorded for the extract.
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Mahmoud, D.A. et al. Neem leaf extracts against human pathogens
The inhibition in the growth of dermatophytes was
explained by changes in hydrophobicity of candidal cells
during assays in yeast adhesion to hydrocarbons (20). This
anti-adhesive mechanism was confirmed later by De Rezende
Ramos et al. (4) who established the effect of neem extracts on
cell surface hydrophobicity and biofilm formation, which affect
the colonization by C. albicans.
In conclusion, the mixture of fractions eluted by HPLC
was more effective than the pure nimonol, the low antifungal
activity even at the highest concentration (20%) may be
explained by a fact that these triterpenoids, in combination
exhibit an additive effect which produce the excellent
antifungal activity recorded in this study for extracts from
neem leaves.
ACKNOWLEDGMENT
The authors wish to thank Center of Statistical Analyses.
Department of Mathematics, Faculty of Scince, El-Monoufya
University for technical support during experiments. The
authors acknowledge the assistance of Dr. Anna Andolfi
(DISPA, Italy) for support during the identification of
nimonol.
REFERENCES
1. Bhatnagar, D. and McCormick, S.P. (1988) : The inhibitory effect of
neem (Azadirachta indica) leaf extracts on aflatoxin synthesis in
Aspergillus parasiticus. Journal of the American Oil Chemists' Society,
65(7): 1166-1168.
2. Bohra, N.K.; Purohit, D.K. (2002). Effect of some aqueous plant extracts
on toxigenic strain of Aspergillus flavus. Advances in Plant Sciences, 15
(1), 103-106.
3. Charmaine Lloyd, A.C.; Menon, T.; Umamaheshwari, K. (2005).
Anticandidal activity of Azadirachta indica. Research Paper, 37(6), 386-
389.
4. De Resende Ramos, A.; Ludke Falcao, L.; Salviano Barbosa, G.; Helena
Marcellino, L.; Silvano Gander, E. (2007). Neem (Azadirachta indica A.
Juss) components: candidates for control of Crinipellis perniciosa and
Phytophthora spp. Microbiol. Res., 162(3), 238-243.
5. Dixit, S.N.; Tripathi, S.C.; Upadhyay, R.R. (1976). The antifungal
substances of rose flowers (Rosa indica). Economic Botany, 30, 344-
371.
6. Dube, S.; Tripathi, S. (1987). Toxicity of some plants against
dermatophytes.National Academy of Sciences, India, Science Letters,
10(2), 45-48.
7. Dubey, R.C.; Dwivedi, R.S. (1991). Fungitoxic properties of some plant
extracts against vegetative growth and sclerotial viability of
Macrophomina phaseolina. Indian phytopathology, 44 : 411-413.
8. Govindachari, T.R.; Gobalakrishnan, G.; Suresh, G. (1996). Isolation of
various Azadirachtins from neem oil by preparative high performance
liquid chromatography. J. Liq. Chromatogr. & Rel. Technol.,19, 1729-
1733.
9. Govindachari, T.R.; Suresh, G.; Gopalakrishnan, G.; Banumathy, B.;
Masilamani, S. (1998). Identification of antifungal compounds from the
seed oil of Azadirachta indica. Phytoparasitica, 26 (2), 1-8.
10. Grewal, P.S.; Grewal, S.K. (1991). Selective fungicidal properties of
some plant extracts to mushroom weed moulds. Phytopathol. Mediterr.,
27(2), 112-114.
11. Joshi, P.C.; Prakash, O.M.; Prakash, O.; Tauro, P.; Narwal, S.S. (1992).
Allelopathic effects of litter extract of some tree species on germination
seedling growth of agricultural crops. Proceedings First National
Symposium. Allelopathy in agroecosystems (Agriculture & foresty),
February 12-14, 1992 held at CCS Haryana Agricultural University,
Hisar 125. 004 , India. 127-128.
12. Khan, M.; Wassilew, S.W.; Schmutterer, H.; Ascher, K.R. (1987). in
Natural Pesticides from the Neem Tree and Other Tropical Plants (eds
Schmutterer, H. and Asher, K.R.), GTZ, Eschborn, Germany, 460-466.
13. Kishore, G.K.; Pande, S.; Rao, J.N. (2001). Control of late leaf spot of
groundnut (Arachis hypogaea) by extracts from non-host plant species.
Plant Pathology Journal, 17(5), 264-270.
14. Lyer, S.R.; Williamson, D. (1991). Efficacy of some plant extracts to
inhibit the protease activity of Trichophyton spesies Geobios Tadhpur ,
8(1), 3-6.
15. Matinuddin, K.; Zubairy, H.N.; Khan, M. (1998). Mycoss. Partl :
antimycotic effect of Azadirachta indica on candida albicans . Hamdard
Medicus, 41(4), 33-34.
16. Natarajan, V.; Pushkala, S.; Karuppiah, V.P.; Prasad, P.V. (2002).
Antidermatophytic activity of Azardirachta indica (neem) by invitro
study. Med Chem Anticancer Agents, 5(2),149-6.
17. Natarajan, V.; Venugopal, P.V.; Menon, T. (2003). Effect of Azadirachta
indica (neem) on the growth pattern of dermatophytes. Indian Journal of
Medical Microbiology, 21(2), 98-101.
18. Okemo, P.O.; Mwatha, W.E.; Chabrab, S.C.; Fabryc, W. (2001). The kill
kinetics of Azadirachta indica A. juss. (Meliacae) extracts on
Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and
Candida albicans. African Journal of Science and Technology (AJST)
1016
Mahmoud, D.A. et al. Neem leaf extracts against human pathogens
Science and Engineering Series, 2(2), 113-118.
19. Pankajalakshmi, V.; Taralakshimi, V. (1994). Antidermatophytic
activity of neem Azadirachta indica leaves in vitro. Indian J. of
Pharmacology, 26: 141-143.
20. Polaquini, S.R.; Svidziniski, T.I.; Kemmelmeier, C.; Gasparetto, A.
(2006). Effect of aqueous extract from neem (Azadirachta indica A.
Juss) on hydrophobicity, biofilm formation and adhesion in composite
resin by Candida albicans. Arch. Oral Biol., 51(6), 482-490.
21. SAS (1988). SAS User's Guide: Statistics. SAS Institute. Cary, N.C.
22. Sharma, V.; Walia, S.; Kumar, J.; Nair, M.G.; Parmar, B.S. (2003). An
efficient method for the purification and characterization of nematicidal
azadirachtins A, B, and H, using MPLC and ESIMS. J Agric Food
Chem., 51(14), 3966-72.
23. Shetty, S.A.; Prakash, H.S.; Shetty, H.S. (1989). Efficacy of certain plant
extracts against seed-born infection of Triconiella padwickii in paddy
(Oryza sativa). Canadian J. of Botany, 67(7), 1956-1958.
24. Shivpuri, A.; Sharma, O.P.; Jhamaria, S.L. (1997). Fungitoxic properties
of plant extracts against pathogenic fungi.Journal of Mycology and Plant
Pathology, 27(1), 29-31.
25. Singh, U.P.; Singh, H.B.; Singh, R.B. (1980). The fungicidal effect of
neem (Azadirachta indica) extracts on some soil borne pathogens,
Mycologia, 7 : 1077-1093.
26. Subapriya, R.; Nagini, S. (2005). Medicinal properties of neem leaves: a
review. Curr. Med. Chem. Anticancer Agents,5 (2),149-160.
27. Suresh, G.; Narasimhan, N.S.; Masilamani, S.; Partho, P.D;
Gopalakrishnan, G. (1997). Antifungal Fractions and Compounds from
uncrushed green leaves of Azadirachta indica. Phytoparasitica, 25(1),
33-39.
28. Trish, D.; Banerjee, S.; Yadava, P.K.; Rao, A.R. (2004).
Chemopreventive potential of Azadirachta indica (Neem) leaf extract in
murine carcinogenesis model systems. Journal of Ethnopharmacology,
92(1), 23-36.
29. Upasana, S.; Anurag, T.; Upadhyay, A.K.; Shukla, U.; Tewari, A.
(2002). In vitro antimicrobial study of Neem (Azadirachta indica) seed
and leaf extracts.Indian Journal of Veterinary Medicine, 22(2), 109-111.
30. Verma, D.K.; Tripathi, V.J.; Rana, B.K. (1998). Antifungal activity of
the seed coat extract of Azadirachta indica. Indian journal of
Pharmaceutical Science, 60(5), 305-306.
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... The application of phyto-biocides is a cheap, sustainable and environmentally sound approach to plant disease control. Many researchers have reported fungicidal and bactericidal effects of plant extract on specific soil borne pathogen [21][22]. In case of bio-agent, it can control many fungi by antagonistic effect. ...
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Potato (Solanum tuberosum) black scurf is caused by Rhizoctonia solani is a seed and soil born disease making severe problem in many potato growing regions in the world since age, resulting huge economic losses. An experiment was conducted by using ecologically sound products, botanicals (Neem, onion, ginger, turmeric and garlic) in laboratory condition as well as in pot condition and bio-agents (Trichoderma viride, Trichoderma asperellu, T. koningii, T. harzianum and T. longibrachiatum) in pot condition to find out the more effective approaches for disease management during two consecutive years. In laboratory, botanicals were amended with Potato Dextrose Agar for growing the fungus and for pot condition potato seed tubers were treated with different concentration of aqueous extract of botanicals and spore suspensions of bio-agents. Among all 15ml, 20ml and 25ml of garlic extract successfully 100% restrict the growth of Rhizoctonia solani. All concentrations of ginger extract were found to be less effective. 25% garlic extract registered 79.22% of eye germination of seed tuber and 5% of ginger extract registered the least 11.84%. Minimum disease incidence (5.68%) and disease severity (0.16%) were recorded in 25% of garlic extract and maximum (disease incidence 78.17% and disease severity 12.95%) were recorded in 5% of ginger extract. T. harzianum did the best at eye germination %, reduction of disease severity and incidence over control during 2 years (89.74%, 83.30% and 57.60% respectively). Oppositely, T. longibrachiatum was not enough efficacious for controlling the disease compare to others. These tested selective treatments can shift effective, profitable and ecologically sound management of this potato disease.
... The leaves, seeds, and roots of neem contain antibacterial and antifungal agents [12,13]. This biological activity of neem stems from many bioactive compounds that are structurally and chemically diverse, with more than 140 compounds found in different parts of the plant [14]. Several types of biological compounds are extracted from neem, including ketones, carotenoids, flavonoids, steroids, and phenolic compounds [15]. ...
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Background Antimicrobial resistance became the leading cause of death globally, resulting in an urgent need for the discovery of new, safe, and efficient antibacterial agents. Compounds derived from plants can provide an essential source of new types of antibiotics. A. indica (neem) plant is rich in antimicrobial phytoconstituents. Here, we used the sensitive and reliable gas chromatography-mass spectrometry (GC–MS) approach, for the quantitative and quantitative determination of bioactive constituents in methanolic extract of neem leaves grown in Sudan. Subsequently, antibacterial activity, pharmacokinetic and toxicological properties were utilized using in silico tools. Results The methanolic extract of neem leaves was found to have antibacterial activity against all pathogenic and reference strains. The lowest concentration reported with bacterial activity was 3.125%, which showed zones of inhibition of more than 10 mm on P. aeruginosa, K. pneumoniae, Citrobacter spp., and E. coli, and 8 mm on Proteus spp., E. faecalis, S. epidermidis , and the pathogenic S. aureus. GC–MS analysis revealed the presence of 30 chemical compounds, including fatty acids (11), hydrocarbons (9), pyridine derivatives (2), aldehydes (2), phenol group (1), aromatic substances (1), coumarins (1), and monoterpenes (1). In silico and in vitro tools revealed that.beta.d-Mannofuranoside, O-geranyl was the most active compound on different bacterial proteins. It showed the best docking energy (-8 kcal/mol) and best stability with different bacterial essential proteins during molecular dynamic (MD) simulation. It also had a good minimum inhibitory concentration (MIC) (32 μg/ml and 64 μg/ml) against S. aureus (ATCC 25,923) and E. coli (ATCC 25,922) respectively. Conclusion The methanolic extract of A. indica leaves possessed strong antibacterial activity against different types of bacteria. Beta.d-Mannofuranoside, O-geranyl was the most active compound and it passed 5 rules of drug-likeness properties. It could therefore be further processed for animal testing and clinical trials for its possible use as an antibacterial agent with commercial values.
... is result was in tandem with some previous studies where they reported that various extracts of A. indica and C. roseus inhibited the growth of CA in their respective experiments [38,39]. It is worthy of note that the standard drugs used, that is, fluconazole and voriconazole, which are triazole antifungal agents, could not inhibit the growth of all the CA strains used, confirming that the strains used were fluconazoleresistant. ...
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e rapid emergence and spread of antimicrobial resistance has become a global public health concern that threatens the effective treatment of infectious diseases. One major approach adopted to overcome antimicrobial resistance is the use of plant extracts individually and/or with combination of antibiotics with plant extracts, which may lead to new ways of treating infectious diseases and essentially representing a potential area for further future investigations. In this study, the antifungal activities of Azadirachta indica leaf and Catharanthus roseus flower extracts against fluconazole-resistant Candida albicans strains (isolated from pregnant women with vulvovaginal candidiasis) and anti-methicillin-resistant Staphylococcus aureus (MRSA) were evaluated by agar well diffusion, microdilution, and biofilm inhibition assays. Subsequently, the determination of the combined antimicrobial activity of the individual plant extracts with (fluconazole and voriconazole) and (ampicillin, tetracycline, and streptomycin) against C. albicans strains and MRSA, respectively, was evaluated by checkerboard microdilution assay. Results from the study showed that the antimicrobial activity of the two plant extracts determined by time-kill kinetics was fungistatic with their MICs ranging from 0.1 to 4 mg/mL. Interestingly, all extracts were proved as good biofilm inhibitors of resistant C. albicans and MRSA from 10.1 to 98.82%. eir combination interaction with fluconazole, voriconazole, ampicillin, tetracycline, and streptomycin ranged from synergy to antagonism as per the parameters used. Overall, these results showed that A. indica leaf and C. roseus flower extracts have significant antifungal property. Furthermore, A. indica leaf and C. roseus flower extracts alone or in combination with fluconazole and voriconazole could provide a promising approach to the management of candidiasis caused by drug-resistant strains as well as their interaction with the antibacterial agents to combat the common infections caused by MRSA.
... In this in vitro study, aqueous, ethanolic and ethyl acetate extracts of leaves of neem have shown significant effect against some human pathogens -Aspergillus flavus, Aspergillus fumigatus, Aspergillus niger, Aspergillus terreus, Candida albicans and Microsporum gypseum in different concentrations (5, 10, 15 and 20%). Among all these 3 extracts, the 20% concentrations of ethyl acetate extract was found to strongest inhibition of growth of these fungal strains and whereas its HPLC analysis showed the presence of nimonol [56] . A recent study has been evaluated that addition of neem powder to acrylic resin denture base materials showed antifungal activity by reducing the adhesion of C. albicans to denture stomatitis [57] . ...
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Drugs of traditional system of medicine including Unani and Ayurveda are recommended and used in various diseases since long. These drugs are mainly derived from herbs and plants. Neem is a pre-eminent and a sacred gift of nature. This tree is still regarded as "Wonder tree", "Nature's drug store", "Divine tree", "Heal all", "Materia medica", "Panacea of all diseases" and "Village dispensary" also considered as "An ancient cure for modern world". In Unani System of Medicine (USM) it is widely used as anti-infective agent in various skin diseases (Amrāḍ-i Jild) such as leprosy, syphilis, tinea, itching and in ulcers. It is very effective in painful menses and dysmenorrhea, chronic joint pain, constipation, intestinal warm (Kirm-i Shikam) and also prefer in the killing of head lices, diabetes and rheumatic arthritis. This study is based on a comprehensive analysis of related articles published in journals using the phrases "Neem or Azadirachta indica ", "Neem research paper", "Neem and Unani Medicine" and "Neem used in traditional medicine" in electronic searches of the PubMed, SCOPUS, Google Scholar advanced search and AYUSH Research Portal. The evidence based scientific and clinical studies reported in the present review confirming the therapeutic efficacy of Azadirachta indica (Neem). Biological active phytoconstituents of Neem also indicate that it may serve as very effective natural medicine in different disease. In this aspect, further in vitro and in vivo studies are needed in respect to explore the recommendations of USM as well as other traditional system of medicines in term of the extensive therapeutic values of Azadirachta indica.
... Several studies have shown that few botanical products exist in agriculture, though there are many commercial products under development . Presently, botanicals that have successfully been separated and marketed as pesticides are pyrethrum (Tanacetum cinerariifolium) (Sharafzadeh, 2011) and neem (Azadirachta indica) (Mahmoud et al., 2011). ...
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Background Worldwide, fruit and vegetable production is permanently affected by many threats including microbial pathogens. Among them, different fungal pathogens cause severe symptoms on fruits in pre- and postharvest. During postharvest, multiple attempts have been made to control the microbial decay of fresh horticultural commodities by using alternatives to synthetic fungicides, which threaten environment and human health. Among these, the use of natural plant products such as plant extracts, essential oils and microbial antagonists has emerged as being the most promising ecological alternative over the last 20 years. Scope and approach There are more than 250,000 plant species worldwide that could be tested for their volatile molecules or bioactive compounds and their biological activity towards microbial species causing postharvest diseases. However, despite their effects against several phytopathogenic fungi, oomycetes and bacteria, the use of plant extracts and essential oils (EOs) in agriculture remains surprisingly limited. Key findings and conclusions The aim of the present review is to gather and discuss up-to-date reports in the scientific literature on the biological activity of EOs and plant extracts against postharvest pathogens. Advances and challenges concerning the innovative methods, potentially valuable to improve the efficiency and reliability of EOs, have been reviewed to find efficient alternative strategies to synthetic fungicides in the control of fruit rot pathogens.
... Gaṇās: Triphalā, [40] Ci. 13/10-12) Pañcanimba. [41] Tablets: Ārogyavardhinī Vaṭi, [42] Gandhaka Rasāyana, [43] Triphalā guggulu, Kaiśora Guggulu. [44] Powders: Pañcanimba, Nimbādi. ...
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Introduction: Mucormycosis is an opportunistic angio-fungal infection that has resurfaced during the COVID-19 pandemic period due to multifarious reasons. Due to the limitations of current interventions associated with it, prevention is the recommended strategy. Ayurveda has a significant role to play in prevention, for which prior understanding of the condition in its own parlance is essential. Materials and Methods: Literature and research works from Ayurveda and Western biomedicine relevant to the subject were identified, screened, explored, and interpreted. The data obtained were grouped into three major criteria: etiological factors, disease patterns, and disease targets. These ideas were grouped to obtain a near-total picture of mucormycosis. A set of recommendations, including diet, regimen, single drugs, formulations, therapeutic procedures, and community-level interventions, were made on the basis of research evidence and textual indications. Results and Discussion: Mucormycosis is an exogenous condition that initially follows a common pathogenetic pattern, localizing at various sites to show diverging manifestations. Kapha and Pitta (especially in terms of Snigdha and Uṣṇa properties) play a major role in preventive and curative strategies in terms of food, regimen, medicine, and therapies. Conclusion: The current Ayurveda knowledge should be effectively used in diagnosing, staging, preventing, and rehabilitating the cases of mucormycoses. Their curative role as adjuvant and standalone therapies are to be subjected to further research.
... Gaṇās: Triphalā, [40] Ci. 13/10-12) Pañcanimba. [41] Tablets: Ārogyavardhinī Vaṭi, [42] Gandhaka Rasāyana, [43] Triphalā guggulu, Kaiśora Guggulu. [44] Powders: Pañcanimba, Nimbādi. ...
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Azadirachta indica, commonly known as neem, or Margosa, originated in India. It is one of the species in the Azadirachta genus. It is native to South Asia's Indian subcontinent and dry areas such as India, Nepal, Sri Lanka, Bangladesh, Pakistan and the Maldives. The plant has long been used in Ayurvedic and folk medicine and it is now commonly used in cosmetics and organic agriculture. Several pharmacological activities were identified from the crude extract of Azadirachta indica, which have attracted a lot of research interest from scientists. This narrative review explores the vast potential of neem in eliciting antibacterial and antifungal effects. Furthermore, we highlight the various effects of different types of solvent and several parts of the neem plant on growth inhibition of bacteria and fungi by performing the inhibition zone technique using the disc diffusion method, one of the commonly used methods to measure bacterial, fungal growth.
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Fungi are unicellular or multicellular thick-walled eukaryotic organisms that are not capable of photosynthesis and are placed in a biological kingdom of their own. They are ubiquitous in our environment, and include tens of thousands, perhaps even millions of species of yeasts, rusts, smuts, mildews, molds, and mushrooms. Together with bacteria, fungi are the principal decomposers of plant materials such as cellulose and lignin, fulfilling vital ecological functions in all terrestrial habitats. Some species of fungi are also of major importance in households (for instance, as foods such as edible mushrooms), medicine (for instance, as producers of antibiotics such as penicillin), and industry (for instance, for making bread, wine, and cheese). About 300 fungal species cause infections in humans, varying from relatively harmless skin complaints such as pityriasis versicolor to potentially life-threatening systemic syndromes such as candidiasis. Fortunately, a broad armamentarium of efficacious antifungal drugs has been developed, ranging from topical nystatin to parenteral amphotericin B. In addition, most, if not all traditional medical systems throughout the world have identified a large assortment of plant-based remedies for treating these infections. This also holds true for the multi-ethnic and multicultural Republic of Suriname (South America), where plant-based traditional medicines are abundantly used, either alone or in conjunction with allopathic medications. This monograph extensively addresses nine plants that are traditionally used for treating fungal infections in Suriname, and explains the phytochemical and pharmacological rationales for these applications. These sections are preceded by some general observations about the Fungal Kingdom; a few words about the characteristics of fungi, their taxonomy, and their significance to humans; information about fungal infections as well as the available forms of treatment; and some details about Suriname including health aspects, the health care structure, and the main fungal infections in the country. The monograph is concluded with an evaluation of the status of the Surinamese herbal antifungal substances and the previsions of developing them into mainstream antifungal formulations.
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The effect of aqueous extracts and oil of neem (Azadirachta indica) on four soil-borne pathogens, Fusarium oxysporum f.sp. ciceri, Rhizoctonia solani, Sclerotium rolfsii, and Sclerotinia sclerotiorum, which incite wilt and rot in gram (Cicer arietinum) was studied. Growth of the four pathogens in liquid medium was inhibited by extracts of leaf, trunk bark, fruit pulp, and oil. Of these four extracts, neem oil showed maximum inhibitory effect. The germination of gram seeds was inhibited at higher concentrations of oil. Oil-treated seeds sown in soil infested with the pathogens singly and intermixed produced disease-free seedlings whereas all the seedlings from untreated seeds exhibited disease symptoms. The fruit pulp suppressed formation of Sclerotium of R. solani at all the concentrations. A possible role of neem extracts and oil in controlling gram diseases in field conditions is suggested.
Article
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The effect of aqueous extracts and oil of neem (Azadirachta indica) on four soil-borne pathogens, Fusarium oxysporum f.sp. ciceri, Rhizoctonia solani, Sclerotium rolfsii, and Sclerotinia sclerotiorum, which incite wilt and rot in gram (Cicer arietinum) was studied. Growth of the four pathogens in liquid medium was inhibited by extracts of leaf, trunk bark, fruit pulp, and oil. Of these four extracts, neem oil showed maximum inhibitory effect. The germination of gram seeds was inhibited at higher concentrations of oil. Oiltreated seeds sown in soil infested with the pathogens singly and intermixed produced disease-free seedlings whereas all the seedlings from untreated seeds exhibited disease symptoms. The fruit pulp suppressed formation of sclerotium of R. solani at all the concentrations. A possible role of neem extracts and oil in controlling gram diseases in field conditions is suggested.
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Purified fraction (ethyl acetate:chloroform; 3:1) of methanolic extract of Azadirachta Indica seed coat showed antifungal activity against Aspergillus niger and Curvularia lunata with a minimum inhibitory concentration of 250 ppm. Among the four extracts (petroleum ether, chloroform, ethyl acetate and methanol) of leaves of Azadirachta indica, petroleum ether extract was found to be antifungal at 1000 ppm.
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The antidermatophytic activity of the aqueous and ethanolic extracts of Neem (Azadirachta indica) leaves was investigated against 88 clinical isolates of dermatophytes by agar dilution. The isolates included Microsporum canis (50), M. audouinii (5), Trichophyton rubrum (6), T. mentagrophytes (5), T. violaceum (12), T. simii (5), T. verrucosum (1), T. soudanense (1), T. erinacei (1) and Epidermophyton floccosum (2). The results were compared with the minimal inhibitory concentrations of ketoconazole. The ethanolic extract was found to be more active inhibiting 90% (MIC 90) of the isolates at a concentration of 100 μg/ml. The MIC 50s and MIC 90s of the aqueous extract were 500 and >500 μg/ml whereas the values for ketoconazole were 1 and 2.5 μg/ml respectively.
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Isolation of various azadirachtins, ie., Azadirachtin A, B, D, H and I in pure form from neem oil by preparative high performance liquid chromatography procedure is described.