Hypocholesterolemic Effect of Aloe vera (L.) Extract on High Cholesterol Fed Calotes versicolor Daudin

Abstract

High blood cholesterol is a major risk factor for heart disease and stroke. Daily supplementation with Aloe vera (L) stimulates immune system and improves wound healing. Study on the effect of Aloe vera (L) extract on the serum cholesterol level on male Calotes versicolor Daudin was carried out in the present study. Calotes versicolor Daudin were made hypercholesterolemic by oral administration of cholesterol (100 mg/kg body weight/day) suspended in ground nut oil using dropper. In one month cholesterol feeding experiment, the serum cholesterol level in normal controls (not given cholesterol) was 321.333 ± 16.621mg/dl and in cholesterol fed animals 437.333 ±8.066 mg/dl. To such animals when different doses of raw extracts of Aloe vera(L.)leaves were given along with cholesterol, there was significant decrease in serum cholesterol level. Four groups of Calotes were administered Aloe vera (L) extract in four different doses (3 mg/kg, 4 mg/kg, 5 mg/kg and 6 mg/kg/day) for 21 days. There was a significant increase in serum cholesterol levels at 1% level after feeding with high cholesterol diet. There was a significant decrease in serum cholesterol levels in all the Aloe vera (L) treated groups. Significance level is 5% for a dose of 6 mg/kg and other doses i.e. of 3 mg/kg, of 4 mg/kg & of 5 mg/kg show significant decrease at 0.1%, 0.5% and 0.2% level, respectively.

Full text

295
Asian J. Exp. Sci., Vol. 22, No. 3, 2008; 295-298
Hypocholesterolemic Effect of Aloe vera (L.) Extract on High
Cholesterol Fed Calotes versicolor Daudin
Mamata Chandrakar*, Sachin Palekar, Sudhir Chirade and Shiba Almas M. Hafiz
Department of Zoology
Government Vidarbha Institute of Science and Humanities,
Amravati-444604 (M.S.); India
Abstract : High blood cholesterol is a major risk factor for heart disease and stroke. Daily
supplementation with Aloe vera (L) stimulates immune system and improves wound healing.
Study on the effect of Aloe vera (L) extract on the serum cholesterol level on male Calotes
versicolor Daudin was carried out in the present study. Calotes versicolor Daudin were made
hypercholesterolemic by oral administration of cholesterol (100 mg/kg body weight/day)
suspended in ground nut oil using dropper. In one month cholesterol feeding experiment, the
serum cholesterol level in normal controls (not given cholesterol) was 321.333 ± 16.621mg/dl
and in cholesterol fed animals 437.333 ±8.066 mg/dl. To such animals when different doses of
raw extracts of Aloe vera(L.)leaves were given along with cholesterol, there was significant
decrease in serum cholesterol level. Four groups of Calotes were administered Aloe vera (L)
extract in four different doses (3 mg/kg, 4 mg/kg, 5 mg/kg and 6 mg/kg/day) for 21 days. There
was a significant increase in serum cholesterol levels at 1% level after feeding with high
cholesterol diet. There was a significant decrease in serum cholesterol levels in all the Aloe
vera (L) treated groups. Significance level is 5% for a dose of 6 mg/kg and other doses i.e. of 3
mg/kg, of 4 mg/kg & of 5 mg/kg show significant decrease at 0.1%, 0.5% and 0.2% level,
respectively.
Key words : Aloe vera(L.), Animal model Calotes versicolor Daudin, Hypercholesterolemia,
Hypocholesterolemic effect.
Introduction
Cardiovascular diseases with an incidence
of approximately 50% are the main cause of
death in most advanced countries (Murray and
Lopez, 1997). Most people would benefit from
lowering their blood pressure and cholesterol
level. The underlying primary cause of
cardiovascular disease is believed to be
arteriosclerosis, a progressive multifactorial
disease of the arterial wall (McDermott, 1999);
Navab et al., 1995). Central to the pathogenesis
of arteriosclerosis is deposition of cholesterol
in the arterial wall (Ross, 1996).
Aloe vera (L) has a long history of both
as an ornamental plant and for herbal
medicine. Aloe vera(L) has been used
externally to treat various skin conditions such
as cuts, burns and eczema. Even though there
are some promising results, clinical
effectiveness of oral or topical Aloe vera(L)
remains unclear at present.Aloe vera (L) juice
may help some people with ulcerative colitis,
an inflammatory bowel disease. Side effects
can occur and consulting a doctor before
ingesting any form of Aloe vera, including Aloe
vera juice, is highly recommended. The lower
leaf of the plant is used for medicinal purpose.
If the lower leaf is sliced open, Aloe vera (L.)
latex—the yellow substance that comes from
the inner side of the skin , the gel obtained can
be applied on the affected area of the skin.
Some people who have reported adverse
effects from Aloe vera (L.) may be ingesting
* Corresponding author : Mamata Chandrakar, Department of Zoology, Govt. Vidarbha Institute of
Science & Humanities, Amravati-444604 (M.S.); India; E-mail: mamatachandra@rediffmail.com

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Chandrakar M. et al. (2008) Asian J. Exp. Sci., 22(3), 295-298
or applying this latex (http://en.wikipedia.org/
wiki/Aloe_vera). A study on the effect of Aloe
vera (L) on the serum cholesterol level was
carried out in the present study.
In the most commonly used method for
testing the hypocholesterolemic effect of
unknown compounds, the experimental animals
are made hypercholesterolemic by feeding
them with cholesterol mixed with the diet (Jain,
1975; Kritchevsky, 1975). This method suffers
from one drawback that the amount of diet
and consequently the amount of cholesterol
taken by each animal is not uniform. therefore
developed an alternate method for inducing
hypercholesterolemia in Calotes versicolor
Daudin. i.e. direct feeding cholesterol to the
animal model (Ratnakar and Murthy,
1998).Then the cholesterol lowering property
with a different doses of Aloe vera(L) extract,
if any is compared.
Material and Methods
Animals:
Healthy, male of Calotes versicolor
Daudin Common Name: Garden lizard Size:
Between 13" and 16”, weighing 25-30 gms.
were used for the study. The animals were
collected from the garden and caged in wooden
boxes with nets on two sides (Box size of
3’x2’x12”). Layer of soil and tiny stones on
the floor of the box and a bulb was used to
heat the vivarium. Sticks were placed inside
the box for the Calotes to climb. The animals
were given standard insect diet and water
throughout the study (http://
www.aqualandpetsplus).
Material samples
A. Aloe vera (L) was identified and
lower leaves were collected from the
Botanical Garden of the Institute . Aloe vera
(L) extract was used.
B. Cholesterol extra pure used for feeding
purpose was from Loba Chemie. Groundnut
oil was used as a vehicle for cholesterol
feeding.
Experimental Procedure
All the animals were weighed and divided
into six groups of six each .
Group I. Normal control fed on insect diet.
Group II. Cholesterol control. Animals of
this group were fed cholesterol at a dose of
100 mg/kg/day body weight for 21 days and
insect diet.
Group III. Animals of this group were fed
cholesterol as in group II and Aloe vera (L)
extract at a dose of 3 mg/kg body weight for
21 days and insect diet.
Group IV. Animals of this group were fed
cholesterol as in group II and Aloe vera (L)
extract at a dose of 4 mg/kg body weight for
21 days and insect diet.
Group V. Animals of this group were fed
cholesterol as in group II and Aloe vera (L)
extract at a dose of 5 mg/kg body weight for
21 days and insect diet.
Group VI. Animals of this group were fed
cholesterol as in group II and Aloe vera (L)
extract at a dose of 6 mg/kg body weight for
21 days and insect diet.
Cholesterol was suspended in groundnut
oil. Calculated amount (100 mg/kg body wt.)
was given to the animal by dropper. Gastric
incubation method was not used because it
damages the alimentary canal of the animal.
To the controls, same volume of groundnut oil
was given; remaining experimental groups were
given cholesterol and different doses of Aloe
vera (L) extract. The animals were
anesthesized on 22
nd
day using anesthetic ether.
Then animals were sacrificed by cutting the
jugular vein. The blood samples were collected
from the jugular vein. Cholesterol was
estimated with kits from Ortho Diagnostics,
Mumbai.
Statistical Analysis
Students t-test (MS Excel) was used. A
p-value < 0.05 was taken as statistically
significant. The serum cholesterol, levels were

297
Aloe vera (L.) on High Cholesterol Fed Calotes versicolor Daudin
compared to the levels of the normal control
and the change was calculated (Zarr Jerrold,
2005).
Results
The plasma cholesterol values and
percentage differences of each group with
level of significance are given in table 1. On
day 22 normal Calotes had a mean ± SD serum
cholesterol level of 321.333 ± 16.621 mg/dl. In
the cholesterol feed control group (group II),
the value on 22
nd
day was 437.333 ±8.066 mg/
dl showing a significant elevation of 36 %
percent from the normal value. In the
experimental group 3 (group III), the value on
22
nd
day was 387.666±3.3862 mg/dl showing
a significant decrease of 11.5% from the value
observed in cholesterol feed control (group II).
In the experimental group IV, the value on 22
nd
day was 350.666 ±10.481 mg/dl showing a
significant decrease of 20 % from the value
observed in cholesterol feed control group II.
In the experimental group V, the value on 22
nd
day was 310 ±6.449 mg/dl showing a significant
decrease of 31.5 % from the value observed
in cholesterol feed control group II as well as
from normal control group I with a 3.5 percent
. In the experimental group VI, the value on
22
nd
day was 265.666 ±5.955 mg/dl showing a
significant decrease of 39.5 percent from the
value observed in cholesterol feed control
group II as well as from normal control group
I with 17.5 percent.
Discussion
There was a significant increase in serum
cholesterol levels at 1% level after feeding with
high cholesterol diet for 21 days. There was a
significant decrease in serum cholesterol levels
in all the Aloe vera (L) treated groups.
Significance level is 5% for a dose of 6 mg/kg
and other doses i.e. of 3 mg/kg, of 4 mg/kg &
of 5 mg/kg show significant decrease at 0.1%,
0.5% & 0.2% level respectively. However the
fall in serum cholesterol was very high i.e.
below normal cholesterol level when the dose
Groups Choles terol level mg/dl
Mean ± S.D.
% of ris e or fall from
cholesterol feed
Control Group II
% of ris e or fall fr om
normal Control
Group I
Group I. Normal
Control
321.333 ± 16.621mg/dl ---------- ---------
Gro u p II. C h o les tero l
feed control
437.333 ±8.066 mg/d l ----------- 36 % ris e
Gro u p III. C h o les te ro l
and Aloe vera extract
at a dose of 3 mg/kg
387.666 ±3.3862 mg/d l 11.5 % fall 20.5 % ris e
Group IV. Cholesterol
and Aloe vera extract
at a dose of 4 mg/kg
350.666 ±10.481 mg/dl 20 % fall 9 % ris e
Group V. Cholesterol
and Aloe vera extract
at a dose of 5 mg/kg
310 ±6.449 mg/d l 31.5 % fall 3.5 % fall
Group VI. Cholesterol
and Aloe vera extract
at a dose of 6 mg/kg
265.666 ±5.955 mg/d l 39.5% fall 17.5 % fall
Table 1 : Serum cholesterol level after 21 days feeding of Aloe vera extract to cholesterol feed Calotes
versicolor, Daudin.

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Chandrakar M. et al. (2008) Asian J. Exp. Sci., 22(3), 295-298
is of 6 mg/kg. As the dose of Aloe vera (L.)
increased there was sharp fall in the serum
cholesterol level. Although Aloe vera (L.) has
been used in some countries as a
hypocholesterolemic agent, there are no
published reports in English, of its action on
lipid profile (McDermott, 1999). Therefore, it
was not possible to compare the results of
present study with previous works.
Probucol, a hypolipidemic drug is a potent
lipophilic antioxidant and the ability to inhibit
atherosclerosis has been attributed to its
antioxidant properties (Witztum, 1996). The
flavonoids present in Aloe vera (L.) may be
responsible for its antioxidant as well as
hypolipidemic action. Aloe vera (L.), according
to reports from the literature has not been used
clinically as a cholesterol-lowering agent.
Conclusion
The deleterious effects of high blood
cholesterol and the beneficial effects of
lowering blood cholesterol in reducing morbidity
and mortality from cardiovascular diseases are
well established. Non-pharmacological
measures like dietary restriction and exercise
may help in lowering blood cholesterol levels.
When such therapy fails in patients with
abnormally high blood cholesterol levels, drug
therapy is indicated. The available drugs like
statins and nicotinic acid, though very effective,
have a spectrum of adverse effects and are
costly. The reason for interest in Aloe vera
(L.) was its low toxicity and the hope that it
might be additive in action with other
cholesterol lowering regimes.
The results of this study showed
significant lowering of serum cholesterol in
Aloe vera (L.) treated animals. But the dose
needs a careful evaluation.
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