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Research Article
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Acute Toxicity Study and Phytochemical Screening of Selected Herbal Aqueous Extract in Broiler Chickens |
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S.R. Hashemi,
I. Zulkifli,
M. Hair Bejo,
A. Farida
and
M.N. Somchit
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ABSTRACT
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In order to collect ethnobotanical information about
growth and health promoter plants as feed additive in broiler chickens,
five medicinal plants Euphorbia hirta, Solanum torvum,
Zingiber officinale, Curcuma longa and Zingiber zerumbet
used by traditional medical practitioners for the treatment of several
ailments of microbial and non-microbial origins were investigated for
phytochemical screening and acute toxicity study. A total of 30 female
broiler chicks were obtained. At 21 days of age, the chicks were allocated
at random into six groups. Five chickens were assigned at random to each
treatment in five replicates and kept in 30 cages (one chickens per cage)
till five weeks of age. Five groups were administered a single oral dose
of 2,000 mg kg-1 b.wt. while 5 mL distilled water was given
to the control group of birds as placebo. Phytochemical screening study
showed that plant contained volatile oils, tannins, alkaloids, saponins,
flavonoids. Alkaloids and steroids were only found in the aqueous extract
of Euphorbia hirta. Tissues were harvested and processed for photomicrographic
examinations. Macro and microscopic observations indicated no alteration
in liver and kidneys of the treated birds with 2000 mg kg-1
of selected herbal plants extract. In the hematological study, a highly
significant decrease was observed in AST, ALT, ALP level of broiler group
receiving the aqueous extract of E. hirta 14 after of administration.
Acute toxicity study indicated that water suspensions of selected herbal
aqueous extract are not toxic when administered by the oral route to experimental
birds at 2000 mg kg-1 b.wt. In conclusion, the results obtained
in the present study are in agreement to a certain degree with the traditional
uses of the plants estimated as prophylaxis against various diseases and
promote of health.
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INTRODUCTION
Antimicrobials have been used as feed supplement for more than 50 years
in poultry feed to enhance the growth performance and to prevent diseases
in poultry. Most of the antibiotic growth promoters take action by modifying
the intestinal flora, which are associated with poor health and reduced
performance of animals. However, in recent years great concern has arisen
about the use of antibiotics as growth and health promoters in poultry
feed due to emergence of multiple drug resistant bacteria and antibiotic
residue effects (Wray and Davies, 2000). There is evidence to suggest
that herbs, spices and various plant extracts have appetizing and digestion-stimulating
properties and antimicrobial effects (Alçiçek et al.,
2004; Zhang et al., 2005). Plant origin like herbs, spices and
various plant extracts are considered to be natural products that consumers
would have received an increased attention and as possible alternatives
to antibiotic growth promoter in improving broiler performance (Hernandez
et al., 2004). Knowledge of the chemical constituents of herbal
plants not only for the discovery of therapeutic agents, but also for
new sources of economic materials is desirable. However, it is important
to establish the chemical constituent and safety of herbal plants before
they are useful on supplement in poultry diet.
Solanum torvum Swartz (Solanaceae) distributed widely in Southeast
of Asia. To date, several alkaloid, steroidal glycosides and long chain
hydrocarbons and steroids have been previously isolated from S. torvum
(Arthan et al., 2002). Zingiberaceae is one of the largest families
of the plant kingdom. Traditionally, the rhizome of Zingiber zerumbet
are employed as medicine in relieving stomachache, macerated in alcohol which is regarded as tonic (Sharifah
Sakinah et al., 2007). Zingiber officinale Roscoe (family,
Zingiberaceae), known commonly as ginger. In Ayurveda, ginger is considered
as valuable medicine because of its action as rubefacient, antiasthmatic
and stimulant to the gastrointestinal tract (Bhandari et al., 1998).
Curcuma longa L., is belongs to the Zingiberaceae family. The powdered
rhizome of C. longa is considered to be stimulating, carminative,
purifying, antiinflammatory and anthelmintic. Externally, the rhizome
mixed with alum lime and saltpetre is applied as a paste to wounds, bruises,
inflamed joints and sprains (Araujo and Leon, 2001; Khattak et al.,
2005).
Euphorbia hirta belongs to the family Euphorbiaceae. The plant
contains relatively abundant white latex. The latex is capable of causing
dermatitis. The plant has been used in traditional medicine for the treatment
of cough, coryza, asthma, bronchial affections (Adedapo et al.,
2005; Hore et al., 2006).
As no information exists in the alternative, the objective of the present
study was to investigate the safety of Euphorbia hirta, Solanum torvum,
Zingiber officinale, Curcuma longa and Zingiber zerumbet
aqueous extract as a dietary additive in poultry diets.
MATERIALS AND METHODS
Plant materials: Whole plant of Euphorbia hirta, edible
fruit of Solanum torvum and rhizomes of Zingiber officinale,
Curcuma longa and Zingiber zerumbet were tested for phytochemical
screening and acute toxicity study. Fresh Euphorbia hirta was collected
in April 2007 from the agriculture gardens in Universiti Putra Malaysia
and other plants were obtained from a local market. The plant specimens
were identified and authenticated by the Institute of Bioscience, Universiti
Putra Malaysia.
Preparation of the extract: Fresh parts of the plant were cleaned,
cut into bits and rinsed with distilled water. The plants were air dried
at room temperature for 24 h, then oven-dried at temperature of 50°C
till they attained a constant weight. The dried plants were then powdered.
In order to obtain the plants extracts, 100 g of each dried plant material
powder was placed in a flask and distilled water was added (1:10 w/v).
The flasks were incubated in a shaking-water bath at 50°C for 48 h
and the obtained extracts were filtered using cotton wool and finally
filter papers (Whatman7
No. 1). The flow-through t were stored in a deep freezer at -80°C
overnight and then subjected to freeze drying (Jouan LP3, France) at -50°C;
0.2 mbar for 48 h to obtain water-free extracts. Extracts were then weighed
and stored at -20°C till further use.
Phytochemical screening: A qualitative phytochemical test was
carried out to detect the presence of volatile oils, alkaloids, tannins,
saponins, flavonoids, glycosides, steroids, terpenoids and phenols utilizing
standard methods of analysis (Sofowora, 1993; Evans, 1996; Haughton and
Raman, 1998). The intensity of the coloration determines the abundance
of the compound present. Qualitative phytochemical analysis of the powder
of the five plants were determined as follows: for tannins one g plant
grinded, then sample was boiled in 20 mL ethanol 70% for 2 min on a hot
plate. The mixture was filtered and a portion of the filtrate diluted
with sterile distilled water in a ratio of 1:4 and 3 drop of 10% ferric
chloride solution added. Blue-black precipitate indicated the presence
of tannins. For phenol 2 mL of extract was added to 2 mL of ferric chloride
solution (FeCl3); a deep bluish green solution is formed with
presence of phenols. The test for alkaloids was carried out by subjecting
5 g ground plant material extracted with 10 mL ammoniacal chloroform and
5 mL chloroform. After filtration, the solution was shaken with 10 drops
aqueous sulphuric acid 0.5 M. Creamish precipitate indicated the presence
of respective alkaloids. For steroids Liebermann-Burchard reaction was
applied. Two hundred milligram plant material boiled in 10 mL chloroform
and the mixture was filtered; a 2 mL filtrate was added to 2 mL acetic
anhydride and concentrated H2SO4. Blue-green ring
indicated the presence of steroids and red color indicated the presence
of terpenoids. The alcoholic extract (15 mL, corresponding to 3 g of plant
material) was treated with a few drops of concentrated HCl and magnesium
Ribbon (0.5 g). Pink-tomato red color indicated the presence of flavonoids.
Froth test for saponins was used. The test for saponin was carried out
by subjecting 5 g of the plant powder extracted with 15 mL methanol. After
evaporation, residue was shaken vigorously with ethyl ether and 5 mL HCl
2N. Precipitate indicated the presence of saponin. For detection of volatile
oils, 1 g fresh plant sample was boiled in 10 mL petroleum ether, filtered
and then 2.0 mL of extract solution was shaken with 0.1 mL dilute sodium
hydroxide and a small quantity of dilute hydrochloric acid. A white precipitate
indicated the presence of volatile oils (Dahiru et al., 2006).
The extract was also tested for free glycoside. Fehling`s solution (A
and B) was added to the extract and the solution was heated on a hot plate
and brick-red precipitate indicated the presence of glycosides.
Acute toxicity study: Acute toxicity test was performed according
to the World Health Organization (WHO) guideline (WHO, 2000) and the Organization
of Economic Co-operation and Development (OECD) guideline for testing
of chemicals (OECD, 2001). A total of 30 one-day-old commercial female
broiler chicks (Cobb 500) were obtained from a local hatchery. Female
broilers were selected because they are generally more sensitive than
males to toxicity study (OECD, 2002). Upon arrival, the chicks were individually
wing-tagged, weighed and assigned in battery cages with wire floors till
21 days. For evaluation of high doses of aqueous extract of the plant,
at 21 days of age, the chickens were weighed (850±21 g) and randomly
divided into 6 groups; each group was further subdivided into 5 replicates
with one chick per cage. One chick was designated as an experimental unit.
Five groups were administered a single oral dose of 2,000 mg kg-1
b.wt. with aqueous extract of selected plants while distilled water was
given to the control group of broiler as placebo. Birds were fed NRC-type
(National Research Council, 1994) experimental diets from Days 1 to 35
(Table 1). The birds were fed starter diet from 1 to
21 days of age and finisher diet from 22 to 35 days of age. Feed and water
were provided ad libitum. Light was provided for 24 h day-1.
All chickens were observed at the first, second fourth, six hour and once
daily thereafter over 14 days [Center for Drug Evaluation and Research
(CDER)] for clinical signs of toxicity.
Histopathological studies: On day 35, all the birds were killed
and their livers and kidneys were removed. Tissues were fixed in 10% neutral-buffered
formalin for 24 h, before being processed for routine paraffin embedding.
Tissues were dehydrated with serial ethanol cycles (70% to absolute),
followed by clarification in xylol and then embedded in paraffin. Embedding
was carried out with a paraffin embedding station (EG 1160; Leica). Duplicate
slides of each block were obtained.
Table
1: |
Ingredients
and nutrient composition of diets |
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1Supplied
per kilogram of diet: Vitamin A, 1,500 IU; Cholecalciferol, 200 IU;
Vitamin E, 10 IU; Riboflavin, 3.5 mg; Pantothenic acid, 10 mg; Niacin,
30 mg; Cobalamin, 10 μg; Choline chloride, 1,000 mg; Biotin,
0.15 mg; Folic acid, 0.5 mg; Thiamine 1.5 mg; Pyridoxine 3.0 mg; Iron,
80 mg; Zinc, 40 mg; Manganese, 60 mg; Iodine, 0.18 mg; Copper, 8 mg;
Selenium, 0.15 mg.
2Based on NRC (1994) feed composition table |
Slices of 5 μm were produced with a rotation microtome (RM 2155;
Leica). Deparaffination was performed with the following protocol: Xylol
4 min; 100% EtOH 2 min; 90% EtOH 2 min; 70% EtOH 2 min; 60%. Afterwards
slices were stained with Mayer hematoxylin and eosin and mounted with
mounting medium (DPX). Sections were then screened under the light microscope
(Leica DM LB2, Leica Microsystems) at low (x5) and high (x40) magnifications
for histopathological study.
Blood sample: Blood samples (4.0 mL) were obtained from each bird
for hematological studies on 0, 7 and 14 days after administration. Plasma
was separated by centrifuged at 3000 g for 10 min and stored at -20°C
until analysis. The levels of total protein, albumin, globuline, urea,
creatinine, alkaline phosphatase (ALP), serum glutamic-oxaloacetic transaminase
(SGOT or AST) and serum glutamic-pyruvic transaminase (SGPT or ALT) were
measured by specific commercial kits (Roche Diagnostica, Basel, Switzerland)
using an autoanalyzer (HITACHI 902 automatic autoanalyzer).
Statistical analysis: Results were expressed as Mean±Standard
error of mean (SEM). Data were analyzed by one-way ANOVA using the general
linear models (GLM) procedure of SAS (SAS7
Institute, 2005). Multiple means comparisons were accomplished using a
Duncan test. p-values less than 0.05 were considered to be significant.
RESULTS
The results of the phytochemical screening of the investigated aqueous
extracts showed the presence of different types of active constituents
like volatile oils, tannins, phenolic, saponins, terpenoids, steroids,
flavonoid and glycosides in Table 2. However, alkaloids
and steroids were only found in the aqueous extract of Euphorbia hirta
in this study.
Bird treated with herbal extract at 2000 mg kg-1 b.wt. did
not show any immediate behavioral changes. The birds moved and drank normally
immediately after administration. After 1 h, all the birds showed signs
of inappetence for 24 h after the treatment. There was no mortality till
14 day after administration (Table 3).
Macro and microscopic observations indicated no alteration in the livers
and kidneys of the treated birds with 2000 mg kg-1 of selected
herbal plants extract (Fig. 1, 2).
The clinical blood chemistry examination was performed in the female
broiler and the results are shown in Table 4. Serum
clinical chemistry showed only a few consistent changes. The data indicate
significant increases in the levels of ALT and AST treated with the aqueous
extract of Zingiber zerumbet at the dose of 2000 mg kg-1
b.wt. after 7 and 14 after administration as compared to the
control groups. On the other hand, a highly significant decrease in AST,
ALT and ALP levels among the groups receiving the aqueous extract of Euphorbia
hirta after 14 day of administration was observed. The highest elevation
in serum ALP was observed in Curcuma longa group during the experimental
period. Total protein, albumin, globulin, creatinine and urea levels were
not different among treatment groups 7 days of administration. Following
14 days of administration, birds given Zingiber zerumbet had the
highest blood urea level. Lowest albumin and creatinine levels
were noted for those given Curcuma longa extract.
Table
2: |
Phytochemical screening of selected herbal plants |
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-:
Absent of phytochemical groups, +: Present of phytochemical groups |
Table
3: |
Toxicity signs observed in broiler (first 24 h) that received oral
single dose (2000 mg kg-1) of the aqueous extract of herbal
plants |
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-:
Absent of phytochemical groups, +: Present of phytochemical groups |
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Fig.
1: |
Liver
histology of untreated and treated broiler with aqueous extract of
selected herbal plants at 2000 mg kg-1 b.wt., C: Control,
Eh: Euphorbia hirta, Zo: Zingiber officinale, Zz:
Zingiber zerumbet, Cl: Curcuma longa, St: Solanum
torvum |
Table
4: |
Clinical
blood chemistry values of female broilers administered with aqueous
extract of herbal plants1,2 |
|
Means
within a column with different letter(s) differ significantly (p<0.05),
Values are expressed as Mean±SEM, n = 5, 1: Groups
were administrated orally with a single dose aqueous extract at
2000 mg kg-1 b.wt., 2: Significantly different
from control, p<0.05 |
|
Fig.
2: |
Kidney
histology of untreated and treated broiler with aqueous extract of
selected herbal plants at 2000 mg kg-1 b.wt., C: Control,
Eh: Euphorbia hirta, Zo: Zingiber officinale, Zz:
Zingiber zerumbet, Cl: Curcuma longa, St: Solanum torvum |
The effects of high dose aqueous extract of selected herbal plants on
feed intake, body weight gain feed conversion in broilers are shown in
Table 5. Following 7 days of administration body weight
gains of birds that were administered with Zingiber zerumbet and
Zingiber officinale were significantly greater than those of the
control groups (p<0.05). The greatest body weight was observed in the
Zingiber zerumbet group at 7 and 14 days after administration of
high dose of aqueous extract. Birds given Zingiber zerumbet had
higher feed consumption throughout the experimental period. At 35 days
of age, the poorest (2.62) feed conversion ratio values were observed
in the Zingiber officinale group (p<0.05) on the other hand,
comparatively better (1.84) FCR values were observed in Solanum torvum
group.
Table
5: |
The
effect of high dose aqueous extract of selected herbal plants on feed
intake, body weight gain feed conversion in broilers |
|
Means
within a column with different letter(s) differ significantly (p<0.05),
All data are expressed as Means±SEM, Broilers were treated
with aqueous extract of selected herbal plants at 2000 mg kg-1
b.wt. |
DISCUSSION
The results of phytochemical screening provide an empirical basis for
the use of these plants in traditional medicinal practices. The biological
or therapeutic activities of medicinal plants are closely related to their
chemicals compounds. The phytochemical screening revealed the presence
of alkaloids and steroid in the aqueous extract of Euphorbia hirta
which explains the reason of using Euphorbia hirta in traditional
remedies for treating infectious diseases such as respiratory disease.
Phytochemicals have been reported to have medicinal uses. Specially, saponin
has been reported to have antimicrobial effects and could serve as precursors
of steroidal substances with a wide range of physiological activities
(Ojo et al., 2006). Alkaloids, commonly isolated from the plants,
are commonly found to have antimicrobial properties (Omulokoli et al.,
1997). Berberine is an important representative of the alkaloid group.
It is potentially effective against trypanosomas and plasmodia (Freiburghaus
et al., 1996; Omulokoli et al., 1997). Nicholas et al.
(2001) screened a variety of marine extracts and identified novel alkaloid
compounds with the ability to inhibit the mycobacterial (Nicholas et
al., 2001). The mechanism of action of highly aromatic planar quaternary
alkaloids such as berberine and harmane (Hopp et al., 1976) is
attributed to their ability to intercalate with DNA (Kumar et al.,
2007).
The toxicological evaluation of a plant extract seeks to determine its
possible collateral effects, to ensure the safety of use. Some phytochemicals
are able to interfere in the toxicity of herbal plants. This toxicity
can be inherent of the herbal plant products or it happens during the
process of extract preparation (Barros et al., 2005). Alldredge
(1993) attributed reduced feed intake in animals fed tannin-containing
diets to strong astringent property of tannins and induction of internal
malaise in mammals, which may contribute to reduced feed intake in poultry.
Increase in feed intake among the Zingiber zerumbet and Zingiber
officinale groups could be due to zingerone`s ability to stimulate
catecholamine secretion from the adrenal medulla (Diepvens et al.,
2007). In a review of peripheral and central control of food intake, Denbow
et al. (1989) detailed the effect of catecholamines and pancreatic
polypeptides exert on feed intake regulation, especially in appetite control
centers of the brain. On the other hand, in traditional medicine by
Zingiber officinale (ginger) and Zingiber zerumbet are believed
to have weight-loss properties, describing it as a root that stimulates
digestion and speeds up the body processes. Therefore, catecholamine secretion
may be explain for the increased feed intake and feed conversion ratio
during experimental period.
Alterations in blood parameters may be due to changes in cellular integrity,
membrane permeability of cells or even due to exposure to toxic chemicals,
(Choudhari and Deshmukh, 2007). In living systems, liver is considered
to be highly sensitive to toxic agents. The study of different enzyme
activities such as AST (SGOT), ALT (SGPT), ALP (SALP) and total protein
have been found to be of great value in the assessment of clinical and
experimental liver damage. Necrosis or membrane damage releases the enzyme
into circulation; therefore, it can be measured in serum. High levels
of AST indicate liver damage, such as that due to viral hepatitis, cardiac
infarction and muscle injury. ALT catalysis the conversion of alanine
to pyruvate and glutamate and is released in a similar manner. Therefore,
ALT is more specific to the liver and is thus a better parameter for detecting
liver injury. The rise in the SGOT is usually accompanied by an elevation
in the levels of SGPT, which plays a vital role in the conversion of amino
acids to keto acids (Hoffbrand and Pettit, 1997; Dash et al., 2007).
Serum ALP level on the other hand, is related to the function of hepatic
cell. Increase in serum level of ALP is due to increased synthesis of
the enzyme, in presence of increasing biliary pressure (Ojo et al.,
2006).
It should be noted that the toxicity dose of selected plants in this
study is not clear. The dose of selected herbal plants used was high,
particularly, if the dose is converted to a corresponding dose in humans
(each dose of 2000 mg kg-1 administered in chickens in the
present study would correspond to 140 g in a 70 kg person). No significant
toxicity has been reported following either acute or chronic administration
of Zingiber zerumbet, Zingiber officinale, Solanum torvum
and Curcuma longa extracts at standard doses. These findings
are consistent with those Faizah et al. (2002) who found that the
extracts of Zingiber zerumbet were devoid of any mortality or behavioral
changes when rats were given up to 500 mg kg-1 i.p in rats
(Faizah et al., 2002). Curcumin is the principal phenolic yellow
pigment in Curcuma longa was given to rats, pigs and monkeys of
both sexes at a dose of 300 mg kg-1 b.wt. No pathological,
behavioural abnormalities or lethality was observed. No adverse effects
were observed on both growth and the level of erythrocytes, leucocytes,
blood constituents such as haemoglobin, total serum protein and ALP. Human
clinical trials also indicate that curcumin has no toxicity when administered
at doses of 1-8 and 10 g day-1 (Chattopadhyay et al.,
2004). In a recent report, up to 12 g of curcumin was administered in
humans without significant toxicity (Poylin et al., 2008). There
has not been any documentation on Solanum torvum toxicity (Israf
et al., 2004).
This finding is in agreement with Ogueke et al. (2007) which showed
that Euphorbia hirta ethanol extract was hematologically not toxic
to rats. However, the findings of the current study do not support the
earlier research by Adedapo et al. (2005) that showed that some
chromatographic fractions of Euphorbia hirta have potentially deleterious
effects on the serum chemistry of rats. Several aspects might explain
this difference. First, it might be related to the ability of birds to
tolerate high doses of plant extract as herbivorous animals to compare
with rat as omnivorous animals. Second, it could be due extraction methods.
There is evidence that the principal active ingredients of the plant must
be more of lipid soluble or non polar, since organic solvent such hexane
and ethanol, are organic solvent which must have easily extracted the
lipid soluble phytochemicals (Cowan, 1999). It has been reported that
plant extracts in organic solvent provided more consistent antimicrobial
activity compared to those extracted in water (Parekh et al., 2005).
Finally, it is well known that the same taxon growing in different areas
may have widely differing chemical components (Eloff, 1999). The efficacy
of medicinal herbs is affected by different environmental factors. Temperature,
rainfall, day length and soil characteristics are some of the factors
which affect the potency of the medicinal plants. A plant may grow well
in different situations, but fail to produce the same constituents (Dubey
et al., 2004).
Acute toxicity study indicated that water suspensions of selected herbal
aqueous extract are not toxic when administered by the oral route to experimental
birds at 2000 mg kg-1 b. wt. In conclusion, the results obtained
in the present study are in agreement to a certain degree with the traditional
uses of the plants estimated. Additionally, based on the results of the
liver enzymes study, apart from the traditional uses, Euphorbia hirta
may also act as a prophylactic agent to prevent liver diseases. The present
results could be a good basis for selection of plant species for further
investigation in the potential discovery of new natural bioactive compounds.
In addition, these plants could represent striking feed additive agents,
which provide prophylaxis against various diseases, growth and health
promoter.
ACKNOWLEDGMENTS
This study was supported by a grant (05-01-04-SF0182) from the Ministry
of Science, Technology and Innovation, Malaysia. The authors gratefully
acknowledge S. Zulkepli, M. Ebrahimi and M. Tabatabaei for their technical
assistance.
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REFERENCES |
1: Adedapo, A.A., M.O. Abatan, S.O. Idowu and O.O. Olorunsogo, 2005. Effects of chromatographic fractions of Euphorbia hirta on the rat serum biochemistry. Afr. J. Biomedical Res., 8: 185-189. Direct Link |
2: Alcicek, A., M. Bozkurt and M. Cabuk, 2004. The effect of a mixture of herbal essential oils, an organic acid or a probiotic on broiler performance. S. Afr. J. Anim. Sci., 34: 217-222. Direct Link |
3: Alldredge, J., 1993. The Effect of Condensed Tannins on Browsers and Grazers: Quantitative and Qualitative defense. 1st Edn., Colorado State University, Fort Collins, Colorado, Direct Link |
4: Araujo, C.A.C. and L.L. Leon, 2001. Biological activities of Curcuma longa L. Memorias Instituto Oswaldo Cruz, 96: 723-728. CrossRef | PubMed | Direct Link |
5: Barros, S., C.D. Ropke, T.C. Sawada, H.V.V. Silva and S.M.M. Pereira et al., 2005. Assessment of acute and subchronic oral toxicity of ethanolic extract of Pothomorphe umbellata L. Miq (Pariparoba). Braz. J. Pharm. Sci., 41: 53-61. CrossRef |
6: Bhandari, U., J.N. Sharma and R. Zafar, 1998. The protective action of ethanolic ginger (Zingiber officinale) extract in cholesterol fed rabbits. J. Ethnopharmacol., 61: 167-171. CrossRef |
7: Chattopadhyay, I., K. Biswas, U. Bandyopadhyay and R.K. Banerjee, 2004. Turmeric and curcumin: Biological actions and medicinal applications. Curr. Sci., 87: 44-53. Direct Link |
8: Choudhari, C.V. and P.B. Deshmukh, 2007. Acute and subchronic toxicity study of Semecarpus anacardium on haemoblobin percent and RBC count of male albino rat. Herbal Medicine Toxicol., 1: 43-45. Direct Link |
9: Cowan, M.M., 1999. Plant products as antimicrobial agents. Clin. Microbiol. Rev., 12: 564-582. CrossRef | PubMed | Direct Link |
10: Dash, D.K., V.C. Yeligar, S.S. Nayak, T. Ghosh and D. Rajalingam et al., 2007. Evaluation of hepatoprotective and antioxidant activity of Ichnocarpus frutescens (Linn.) R.Br. on paracetamol-induced hepatotoxicity in rats. Trop. J. Pharm. Res., 6: 755-765. Direct Link |
11: Dahiru, D., J.A. Onubiyi and H.A. Umaru, 2006. Phytochemical screening and antiulcerogenic effect of Moringa oleifera aqueous leaf extract. Afr. J. Tradit. Complement. Altern. Med., 3: 70-75. Direct Link |
12: Denbow, D.M., G.E. Duke and S.B. Chaplin, 1989. . Food intake, gastric secretion, and motility as affected by avian pancreatic polypeptide administered intraceberebrally in chickens. Peptides, 9: 449-454. Direct Link |
13: Diepvens, K., K.R. Westerterp and M.S. Westerterp-Plantenga, 2007. Obesity and thermogenesis related to the consumption of caffeine, ephedrine, capsaicin, and green tea. Am. J. Physiol. - Regulatory Integrative Comparative Physiol., 292: 77-85. CrossRef | Direct Link |
14: Dubey, N.K., R. Kumar and P. Tripathi, 2004. Global promotion of herbal medicine: India's opportunity. Curr. Sci., 86: 37-41. Direct Link |
15: Eloff, J.N., 1999. It is possible to use herbarium specimens to screen for antibacterial components in some plants. J. Ethnopharmacol., 67: 355-360. Direct Link |
16: Evans, W.C., 2002. Trease and Evans Pharmacognosy. 5th Edn., W.B. Saunders Ltd., London, ISBN: 0-7020-2617-4, pp: 119-159
17: Faizah, S., M.N. Somchit and M.H. Shukriyah, 2002. Zingiber zerumbet (Lempoyang): A potential anti-inflammatory agent. Proceedings of the Regional Symposium on Environment and Natural Resources, April 10-11, 2002, Kuala Lumpur, Malaysia, pp: 516-520 Direct Link |
18: Freiburghaus, F., R. Kaminsky, M.H.H. Nkunya and R. Brun, 1996. Evaluation of African medicinal plants for their in vitro trypanocidal activity. J. Ethnopharmacol., 55: 1-11. CrossRef | Direct Link |
19: Gruenigen, V.E., A.L. Showalter, K.M. Gil, H.E. rasure and M.P. Hopkins et al., 2001. Complementary and alternative medicine use in the amish. Complementary Terapies Med., 9: 232-233. CrossRef |
20: Haughton, P.J. and A. Raman, 1998. Laboratory Handbook for the Fractionation of Natural Extracts. 1st Edn., Chapman and Hall London, UK., ISBN-13: 9780412749100, Pages: 199
21: Hernandez, F., J. Madrid, V. Garcia, J. Orengo and M.D. Megias, 2004. Influence of two plant extracts on broilers performance, digestibility and digestive organ size. Poult. Sci., 83: 169-174. CrossRef | PubMed | Direct Link |
22: Hoffbrand, A.V. and J. E. Pettit, 1997. Essential of Haematology. 4th Edn., Blackwell Science Inc., USA., ISBN: 0-632-05153-1
23: Hopp, K.H., L.V. Cunningham, M.C. Bromel, L.J. Schermeister and S.K.W. Khalil, 1976. In vitro antitrypanosomal activity of certain alkaloids against Trypanosoma lewisi. Lloydia, 39: 375-377. PubMed |
24: Israf, D.A., N.H. Lajis, M.N. Somchit and M.R. Sulaiman, 2004. Enhancement of ovalbumin-specific IgA responses via oral boosting with antigen co-administered with an aqueous Solanum torvum extract. Life Sci., 75: 397-406. CrossRef |
25: Kattak, S., Saeed-ur-Rehman, H.U. Shah, W. Ahmad and M. Ahmad, 2005. Biological effect of indigenous medicinal plants Curcuma longa and Alpina galangal. J. Fitoterpia, 76: 254-257. CrossRef |
26: Nicholas, G.M., G.L. Newton, R.C. Fahey and C.A. Bewley, 2001. Novel bromotyrosine alkaloids: Inhibitors of mycothiol S-conjugate amidase. Organic Lett., 3: 1543-1545. PubMed |
27: NRC., 1994. Nutrient Requirements of Poultry. 9th Edn., National Academy Press, Washington, DC., USA., ISBN-13: 9780309048927, Pages: 155 Direct Link |
28: Ogueke, C.C., J.N. Ogbulie, I.C. Okoli and B.N. Anyanwu, 2007. Antibacterial activities and toxicological potentials of crude ethanolic extracts of Euphorbia hirta. J. Am. Sci., 3: 11-16. Direct Link |
29: Ojo, O.O., M.S. Nadro and I.O. Tella, 2006. Protection of rats by extracts of some common Nigerian trees against acetaminophen-induced hepatotoxicity. Afr. J. Biotechnol., 5: 755-760. Direct Link |
30: Omulokoli, E., B. Khan and S.C. Chhabra, 1997. Antiplasmodial activity of four Kenyan medicinal plants. J. Ethnopharmacol., 56: 133-137. CrossRef | PubMed | Direct Link |
31: Parekh, J., D. Jadeja and S. Chanda, 2005. Efficacy of aqueous and methanol extracts of some medicinal plants for potential antibacterial activity. Turk. J. Biol., 29: 203-210. Direct Link |
32: Kumar, G.S., K.N. Jayaveera, C.K.A. Kumar, U.P. Sanjay and B.M.V. Swamy et al., 2007. Antimicrobial effects of Indian medicinal plants against acne-inducing bacteria. Trop. J. Pharm. Res., 6: 717-723. Direct Link |
33: Poylin, V., M.U. Fareed, P. O’Neal, N. Alamdari and N. Reilly et al., 2008. The NF-κB inhibitor curcumin blocks sepsis-induced muscle proteolysis. Mediators Inflammation, 2008: 1-13. CrossRef |
34: Sofowora, A., 1993. Medicinal Plants and Traditional Medicine in Africa. 2nd Edn., Spectrum Books Ltd., Ibadan, Nigeria, ISBN-13: 9782462195, Pages: 289
35: Somchit, M.N., M.H.N. Shukriyah, A.A. Bustammam and A. Zuraini, 2005. Anti-pyretic and analgesic activity of Zingiber zerumbet. Int. J. Pharmacol., 277: 277-280. CrossRef | Direct Link |
36: Wray, C. and R.H. Davies, 2000. Competitive exclusion-an alternative to antibiotics. Vet. J., 159: 107-108. CrossRef | PubMed |
37: Zhang, K.Y., F. Yan, C.A. Keen and P.W. Waldroup, 2005. Evaluation of microencapsulated essential oils and organic acids in diets for broiler chickens. Int. J. Poult. Sci., 4: 612-619. CrossRef | Direct Link |
38: Hore, S.K., V. Ahuja, G. Mehta, P. Kumar, S.K. Pandey and A.H. Ahmad, 2006. Effects of aqueous Euphorbia hirta leaf extract on gastrointestinal motility. Fitoterapia, 77: 35-38. CrossRef |
39: Arthan, D., J. Svasti, P. Kittakoop, D. Pittayakhachonwut, M. Tanticharoen and Y. Thebtaranonth, 2002. Antiviral iosflavonoid sulfate and steroidal glycosides from the fruits of Solanum torvum. Phytochemistrym, 59: 459-463. CrossRef |
40: Sakinah, S.A.S., S.T. Handayani and L.P.A. Hawariah, 2007. Zerumbone induced apoptosis in liver caner cells via modulation of Bax/Bcl-2 ratio. Cancer Cell Int., 7: 4-4. CrossRef | PubMed |
|
|
|
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