# Anxiolytic and Anticonvulsant Effects on  Mice of Flavonoids, Linalool, andα-Tocopherol Presents in  the Extract of Leaves of Cissus sicyoides L. (Vitaceae)

Authors: Edvaldo Rodrigues de Almeida; Krissia Rayane de Oliveira Rafael; Geraldo Bosco Lindoso Couto; Ana Beatriz Matos Ishigami
Journal: Journal of Biomedicine and Biotechnology
 (2009)

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## Abstract

The aim of the present study is to demonstrate the anxiolytic and anticonvulsant effects of a hydroalcoholic extract obtained from the aerial parts ofCissus sicyoides L. (CS) (Vitaceae) on male and female mice using several behavioral assays. Groups of males and females treated via intraperitoneal (IP) with doses of 300, 600, and 1000 mg/kg of the extract showed significant action in the elevated plus-maze (EPM), time spent in the open arms, and number of entries in the open arms. The board-hole test also showed a significant increase in the time spent in head-dipping and in marble-burying test of the number of marbles buried. The same treatment increased the duration of sleeping time induced by sodium pentobarbital and also showed a significant increase in protection against pentylenotetrazole-induced convulsions. These results indicate an anxiolytic and anticonvulsant-like action from  C. sicyoides L. extract on mice, probably due to the action of flavonoid(s), Linalool, and α-tocopherol present in the C. sicyoides leaves.


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## Body

## 1. Introduction

Cissus sicyoides (CS)  belonging to the Vitaceae family
comprises of about 165 genus and 1370 species, which are distributed throughout
the tropics, mainly in Brazil and the Caribbean. It is popularly known as “insulinas, cipo-pucá,
bejuco de porra, bejuco caro, puci, and anil trepador” [1]. Originally from the Dominican Republic
[2], it is used in popular medicine as a diuretic, anti-inflammatory, and
antidiabetic [3, 4]. It has also demonstrated a vasoconstrictor effect on guinea-pig
aorta rings [5] and an antibacterial activity [6]. In Brazil, CS was
evaluated for its anticonvulsant property, where it is used against epilepsy andcytotoxic activities [7–9]. The fact that
treatment with tea induced an increase in the amount of chromosomal damage in
bone marrow cells without altering the cell division cycle was also
demonstrated. This plant also presents antibacterial and oxytocic activities [10],
and CS contains significant amounts of α-tocoferol, a compound proved to be a
useful adjunct to anticonvulsants in clinical medicine [11]. Alpha-tocopherol protects against
pentylenotetrazol and methylmalonate-induced
convulsions [12] and prevents
the occurrence of epileptic foci in a rat model of posttraumatic epilepsy [13]. The central antinociceptive effect of C. sicyoides on mice as well as the action of dry leaves extract in
pregnant rats and offspring postal development was also demonstrated. [14–16].
Phytochemistry studies identified and isolated from the aerial parts of CS a new coumarin glycoside
5,6,7,8-tetrahydroxycoumarin-5β-xylopyranoside
which was obtained together with known coumarin sabandin, two flavonoids
kaempferol 3-rhamnoside and quercetin 3-rhamnoside, and two steroids,
sitosterol and 3β-O-β-d-glucopyranosylsitosterol
[17] (see Figure 1). Leaves of the genus Cissus contain sterols, quinones, and phenolic compounds. Anthocyanins, saponins, and
flavonoids are also found in the plants leaves and fruits [3]. The effect of
linalool present in the leaves of the CS wasdemonstrated in the protection against seizures induced in mice [7, 8, 18] (see Figure 2). However, we found no reference on its activity on the central nervous system (CNS)
relating to anxiety as well as information on its acute toxicity.
Benzodiazepines (BDZs) are considered safe drugs and are widely prescribed for
their anxiolytic and anticonvulsant actions [19–21]. However,
they may produce side effects, such as sedation and myorelaxation that are
considered as unwanted effects in an anxiolytic drugs [20]. On the other hand,
the existence of natural flavonoids that possess anxiolytic effect not
associated with myorelaxant, amnesic, or sedative actions has been demonstrated
[22]. Although alternative
treatments with herbs are increasingly used by the population to alleviate
affective disorders, there is a strong rejection among doctors as the use of
herbs for treatment of various diseases is still scarce [23]. The antidiabetic action of the CS is in
the making of clinical trials (phase II), the results obtained by the authors
are promising for the future use in medical clinics [24]. This study also aims
to assess the possible effects of flavonoids in the hydroalcoholic extract of
the CS leaves in several behavioral tests related to anxiety in mice. The
presence of α-Tocopherol has been
identified in the leaves of C. sicyoides,
used in clinical practice as an adjunct in the treatment of seizures [11]
(see Figure 3). Our result indicates a new action for use of the C. sicyoides which can be related to the
presence of the α-tocopherol as an adjuvant of the effect of sedatives together
with the linalool and flavonoids present in this plant.Figure 1
Flavonoids molecular structure present inC. sicyoides leaves,
(1) canferol 3-a-ramínosideo and (2) quercetina 3-a-raminosídeo.Figure 2
Linalool
molecular structure present inCissus sicyoides leaves, 2,
6-dimethylocta-2,7-dien-6-ol; 3,7-dimethyl-1,6-octadien-3-ol.Figure 3
Molecular structure ofα-tocopherol,
(2R)-2,5,7,8-tetramethyl-2-[(4R,8R)-4,8,12-trimethyltridecyl]-3,4-dihydro-2H-chromen-6-ol.Figure 4
Effect of sodium pentobarbital (PBS-) induced sleep
time was evaluated with the extracts (EHDg and EADg). All data cited are the
mean ±S.D. The data were evaluated by a one-way analysis of variance (ANOVA)
with Duncan's post hoc test. This figure shows that the doses used had a hypnotic effect very
significant with relation to the effect of PBS*[F (1.7) = 5.5; P<.01]. 10
animals were used in each group.


## 2. Materials and Methods

### 2.1. Plant Material and Extract Preparation

Aerial parts of CS were collected in the vicinity of the campus of the
Federal University of Pernambuco—State of Pernambuco—Brazil in
January 2005. The plant was identified by University Prof. Marlene Carvalho de
Alencar Barbosa, and a vouched for specimen was deposited in the Geraldo Mariz
Herbarium (UFP) under Botanical Department N° 29040. The collected leaves were
washed, dried at room temperature (28°C) in the laboratory for 25
days and ground in a mill to a grain size of <1 mm. Then, 360 grams of the
powdered plant material were
added to 1000 mL of alcohol and water (70:30, v/v). The dry powder yielded 30%
of extract. For pharmacological testing, the extract was dissolved in saline
plus Tween 80 (0.025%) solution.


### 2.2. Animals

Male and female two-month-old Swiss albino mice, weighing 20–30 g, were used in
this experiment. The animals were housed in groups of ten per cage, with
light/dark periods of 12 hours. They were fed and watered ad libitum. All experiments were
conducted between 10:00 am and 4:00 pm. Female mice
were tested without monitoring the oestrus cycle. All the animals were
carefully monitored and maintained in accordance with the ethical
recommendation of the Brazilian College of Animal
Experimentation (COBEA) and the National Institute of Health Guide for Care and
use of Laboratory Animals and approved by the Ethical Committee of the Federal
University of Pernambuco (UFPE) protocol number 008196/2005-29.


### 2.3. Drugs

Diazepam (DPZ, 2.5 mg/kg, IP) was used as the standard anxiolytic drug. Pentobarbital
sodium (PBS, 55 mg/kg, IP) was used as a hypnotic drug and pentylenotetrazole
(PTZ, 55 mg/kg, IP) as a convulsant. All drugs were obtained from Sigma Aldrich, Mo, USA, and
Tween 80 was locally purchased.


### 2.4. Sodium Pentobarbital-Induced Sleeping Time

The mice were divided into four groups (10 animals/group). Three groups received
three doses of extract (300, 600, and 1000 mg/kg (IP). After 1 hour, all four
groups received 55 mg/kg (IP) of sodium pentobarbital (PBS). The time that
elapsed between the loss and recovery of the righting reflex was recorded, for
control and drug pretreated animals [25].


### 2.5. Pentylenotetrazole-Induced Convulsion

The mice were divided into four groups (10 animals/group). The first group received
the pentylenotetrazole (PTZ) (55 mg/kg IP) and served as positive control. The test groups received the CS extract at doses of 300, 600, and 1000 mg/kg
(IP). After 1 hour, PTZ (55 mg/kg, IP) was administered to the animals in
each group. The number of mice which exhibited convulsions, the lethal time,
and the latency to first convulsion was recorded [25].


### 2.6. Marble-Burying Test

Twenty-five
clear glass marbles (20 mm diameter) were used for each individual test. Opaque
cages (30×36×13 cm) were constructed of smooth, opaque plastic with a vinyl
ceiling containing air holes, and a 5 cm layer of sawdust. Mice were placed
individually in these cages for 15 minutes (habituation trial) and then
returned to their home cage. Twenty-five
glass marbles were evenly spaced 5 cm apart on a 5 cm layer of sawdust in the
habituation cages. Mice were then reintroduced (each test mouse was returned to
the same cage in which they had been habituated). 10 animals were used in each
group. The test groups received the CS extract at doses of 300, 600, and 1000 mg/kg (IP). After 15 minutes, the test was terminated by removing the mice
and counting the number of marbles that were more than two-thirds covered with
sawdust. After each trial, the sawdust was replaced, and the test apparatus and
glass marbles were washed by water and cleaned with 70% alcohol [26, 27].


### 2.7. Board-Hole Test

Exploratory
behavior was assessed using the board-hole test [28]. The apparatus consisted of a
square plastic plate, 40 cm × 40 cm, 1 cm thick, with
16 holes (diameter 2 cm), regularly spaced on the surface, at 3.5 cm
from the edges. The apparatus was elevated to the height of 50 cm, in a
dimly illuminated room. Mice were placed in the centre of the plate, and the
number of head dips was immediately counted during two or three consecutive
periods of 5 minutes each.


### 2.8. Elevated Plus-Maze Test

The elevated plus-maze
(EPM) test consisted of two open arms (30×5×0.25 cm) and two closed arms
(30×5×15 cm) emanating from a common central platform (5×5 cm). Two pairs
of identical arms were opposite to each other. The entire apparatus was
elevated to a height of 40 cm above floor level. At the beginning of the
session, a mouse was placed at the centre of the maze, its head facing an open
arm and allowed to explore the maze for 5 minutes, and the following parameters
were scored: the time spent and number of entries in each type of arms. The plus
maze was carefully cleaned with a wet towel after each animal test. The mice
were divided into four groups (10 animals/group). DPZ (2.5 mg/kg, IP) was
used as the positive control and CS extract at doses of 300, 600, and 1000 mg/kg, i.p, in the three remaining groups. All experiments were carried out
between 10:00 am and 4:00 pm. After each trial, the EPMapparatus was wiped clean with alcohol (70%) solution [29].


### 2.9. Statistical Analysis

Statistical
analysis was performed using one-way ANOVA with post hoc Duncan's test.P<.05 was considered significant. All data are expressed
as mean ±S.D.


## 2.1. Plant Material and Extract Preparation

Aerial parts of CS were collected in the vicinity of the campus of the
Federal University of Pernambuco—State of Pernambuco—Brazil in
January 2005. The plant was identified by University Prof. Marlene Carvalho de
Alencar Barbosa, and a vouched for specimen was deposited in the Geraldo Mariz
Herbarium (UFP) under Botanical Department N° 29040. The collected leaves were
washed, dried at room temperature (28°C) in the laboratory for 25
days and ground in a mill to a grain size of <1 mm. Then, 360 grams of the
powdered plant material were
added to 1000 mL of alcohol and water (70:30, v/v). The dry powder yielded 30%
of extract. For pharmacological testing, the extract was dissolved in saline
plus Tween 80 (0.025%) solution.


## 2.2. Animals

Male and female two-month-old Swiss albino mice, weighing 20–30 g, were used in
this experiment. The animals were housed in groups of ten per cage, with
light/dark periods of 12 hours. They were fed and watered ad libitum. All experiments were
conducted between 10:00 am and 4:00 pm. Female mice
were tested without monitoring the oestrus cycle. All the animals were
carefully monitored and maintained in accordance with the ethical
recommendation of the Brazilian College of Animal
Experimentation (COBEA) and the National Institute of Health Guide for Care and
use of Laboratory Animals and approved by the Ethical Committee of the Federal
University of Pernambuco (UFPE) protocol number 008196/2005-29.


## 2.3. Drugs

Diazepam (DPZ, 2.5 mg/kg, IP) was used as the standard anxiolytic drug. Pentobarbital
sodium (PBS, 55 mg/kg, IP) was used as a hypnotic drug and pentylenotetrazole
(PTZ, 55 mg/kg, IP) as a convulsant. All drugs were obtained from Sigma Aldrich, Mo, USA, and
Tween 80 was locally purchased.


## 2.4. Sodium Pentobarbital-Induced Sleeping Time

The mice were divided into four groups (10 animals/group). Three groups received
three doses of extract (300, 600, and 1000 mg/kg (IP). After 1 hour, all four
groups received 55 mg/kg (IP) of sodium pentobarbital (PBS). The time that
elapsed between the loss and recovery of the righting reflex was recorded, for
control and drug pretreated animals [25].


## 2.5. Pentylenotetrazole-Induced Convulsion

The mice were divided into four groups (10 animals/group). The first group received
the pentylenotetrazole (PTZ) (55 mg/kg IP) and served as positive control. The test groups received the CS extract at doses of 300, 600, and 1000 mg/kg
(IP). After 1 hour, PTZ (55 mg/kg, IP) was administered to the animals in
each group. The number of mice which exhibited convulsions, the lethal time,
and the latency to first convulsion was recorded [25].


## 2.6. Marble-Burying Test

Twenty-five
clear glass marbles (20 mm diameter) were used for each individual test. Opaque
cages (30×36×13 cm) were constructed of smooth, opaque plastic with a vinyl
ceiling containing air holes, and a 5 cm layer of sawdust. Mice were placed
individually in these cages for 15 minutes (habituation trial) and then
returned to their home cage. Twenty-five
glass marbles were evenly spaced 5 cm apart on a 5 cm layer of sawdust in the
habituation cages. Mice were then reintroduced (each test mouse was returned to
the same cage in which they had been habituated). 10 animals were used in each
group. The test groups received the CS extract at doses of 300, 600, and 1000 mg/kg (IP). After 15 minutes, the test was terminated by removing the mice
and counting the number of marbles that were more than two-thirds covered with
sawdust. After each trial, the sawdust was replaced, and the test apparatus and
glass marbles were washed by water and cleaned with 70% alcohol [26, 27].


## 2.7. Board-Hole Test

Exploratory
behavior was assessed using the board-hole test [28]. The apparatus consisted of a
square plastic plate, 40 cm × 40 cm, 1 cm thick, with
16 holes (diameter 2 cm), regularly spaced on the surface, at 3.5 cm
from the edges. The apparatus was elevated to the height of 50 cm, in a
dimly illuminated room. Mice were placed in the centre of the plate, and the
number of head dips was immediately counted during two or three consecutive
periods of 5 minutes each.


## 2.8. Elevated Plus-Maze Test

The elevated plus-maze
(EPM) test consisted of two open arms (30×5×0.25 cm) and two closed arms
(30×5×15 cm) emanating from a common central platform (5×5 cm). Two pairs
of identical arms were opposite to each other. The entire apparatus was
elevated to a height of 40 cm above floor level. At the beginning of the
session, a mouse was placed at the centre of the maze, its head facing an open
arm and allowed to explore the maze for 5 minutes, and the following parameters
were scored: the time spent and number of entries in each type of arms. The plus
maze was carefully cleaned with a wet towel after each animal test. The mice
were divided into four groups (10 animals/group). DPZ (2.5 mg/kg, IP) was
used as the positive control and CS extract at doses of 300, 600, and 1000 mg/kg, i.p, in the three remaining groups. All experiments were carried out
between 10:00 am and 4:00 pm. After each trial, the EPMapparatus was wiped clean with alcohol (70%) solution [29].


## 2.9. Statistical Analysis

Statistical
analysis was performed using one-way ANOVA with post hoc Duncan's test.P<.05 was considered significant. All data are expressed
as mean ±S.D.


## 3. Results

### 3.1. Sodium Pentobarbital-Induced Sleeping Time

The effect of pentobarbital sodium-induced
sleep is shown in Figure1. The values, up to 1000 mg/kg of CS, were
significantly different from the control group
*[F (1.7) = 5.5; P<.01].


### 3.2. Effect of CS Pentylenotetrazole(PTZ-) Induced Convulsion

The CS inhibited generalized clonic-tonic convulsions induced by PTZ (55 mg/kg, IP) at doses of 600 and
1000 mg/kg (Figure5), as in
accordance with statistical analysis
*[F(1.6) = 5.7; P<.01], using
analysis of variance one way (ANOVA) and followed by a post hoc Duncan's test.Figure 5
Effect of pentylenotetrazole (PTZ-) induced
convulsion was evaluated with the extracts (EHDg and EADg). All data cited are
the mean ±S.D. The data were evaluated by a one-way variance analysis (ANOVA)
with Duncan's post hoc test. This figure shows that the doses
effective in protecting against seizure were 600 and 1000 mg/kg*[F (1.6) = 5.7; P<.01].10 animals were used in each group.


### 3.3. Marble-Burying Test

To examine this premise,
we studied the effect of the representative of CS on burying behavior. As
expected, control exhibited significant decrease in the marble burying
behavior. However, CS prompted an increase in marble burying (300, 600, and
100 mg. kg1, IP. These data were evaluated using the analysis of
variance one way (ANOVA) followed by a post hoc Duncan's tests.
*[F (1.14)
= 5.8; P<.01], and
**[F (1.12) = 5.7; P<.05]  (Figure 6).Figure 6
Effect of extracts (EHDg and
EADg) in Marble-burying test. The extracts were evaluated in relation to
Diazepam. All data cited are the mean ±S.D. The data were evaluated by a
one-way variance analysis (ANOVA) with Duncan's post hoc test. The data from
this figure show that the effect of fear produced by glass beads was significant compared
with the control and the diazepam*[F
(1.14) = 5.8; P<.01], and
**[F (1.12)
= 5.7; P<.05]. 10 animals were used in each group.


### 3.4. Effect of Board-Hole Test

The effect of CS on the board-hole
test is shown in Figure7. At the doses of 300, 600, and 100 mg/kg, IP, a
significant increase in the amount of head-dipping behavior was shown
*[F
(1.13) = 5.7;
P<.001].Figure 7
Time spent in head-dip registered in a 5-minute session in
the board-hole test performed 1 hour after administered do control, diazepam
(2.5 mg/kg), and CS. In this test, all doses used showed a very significant
effect on the control and similar to diazepam*[F
(1.13) =  5.7; P<.01]. 10
animals were used in each group.


### 3.5. Effect of CS on the Elevated Plus-Maze (EPM)

CS in all the doses (300, 600, and
1000 mg/kg, IP) produced anxiolytic-like effects as determined by the
increase in the percentage of open arm entries*[F (1.14) = 5.6; P<.01].
Conversely, the number of entries and the time spent in the closed arms were reduced
by CS treatment [F (1.13) = 5.5; P<.01]  (Figures 8
and 9).Figure 8
Effect of diazepam and of CS on the values of time spent in the open arms during 5 minutes. The
data from this figure show that the dose of 1000 mg/kg was not significant in
relation to the vehicle and Diazepam.*[F (1.14) = 5.6; P<.01*P<.01]  and  **[F (1.1) = 55; P<.05]. 10 animals were used in each group.Figure 9
Effect of diazepam and the extract of CS on the values of time spent in the closed arms, during 5 minutes. All doses used in this test had a time of
permanence in the closed arm very significant in relation to the vehicle, and
similar to diazepam*[F (1.13) = 5.5; P<.01]. 10
animals were used in each group.


## 3.1. Sodium Pentobarbital-Induced Sleeping Time

The effect of pentobarbital sodium-induced
sleep is shown in Figure1. The values, up to 1000 mg/kg of CS, were
significantly different from the control group
*[F (1.7) = 5.5; P<.01].


## 3.2. Effect of CS Pentylenotetrazole(PTZ-) Induced Convulsion

The CS inhibited generalized clonic-tonic convulsions induced by PTZ (55 mg/kg, IP) at doses of 600 and
1000 mg/kg (Figure5), as in
accordance with statistical analysis
*[F(1.6) = 5.7; P<.01], using
analysis of variance one way (ANOVA) and followed by a post hoc Duncan's test.Figure 5
Effect of pentylenotetrazole (PTZ-) induced
convulsion was evaluated with the extracts (EHDg and EADg). All data cited are
the mean ±S.D. The data were evaluated by a one-way variance analysis (ANOVA)
with Duncan's post hoc test. This figure shows that the doses
effective in protecting against seizure were 600 and 1000 mg/kg*[F (1.6) = 5.7; P<.01].10 animals were used in each group.


## 3.3. Marble-Burying Test

To examine this premise,
we studied the effect of the representative of CS on burying behavior. As
expected, control exhibited significant decrease in the marble burying
behavior. However, CS prompted an increase in marble burying (300, 600, and
100 mg. kg1, IP. These data were evaluated using the analysis of
variance one way (ANOVA) followed by a post hoc Duncan's tests.
*[F (1.14)
= 5.8; P<.01], and
**[F (1.12) = 5.7; P<.05]  (Figure 6).Figure 6
Effect of extracts (EHDg and
EADg) in Marble-burying test. The extracts were evaluated in relation to
Diazepam. All data cited are the mean ±S.D. The data were evaluated by a
one-way variance analysis (ANOVA) with Duncan's post hoc test. The data from
this figure show that the effect of fear produced by glass beads was significant compared
with the control and the diazepam*[F
(1.14) = 5.8; P<.01], and
**[F (1.12)
= 5.7; P<.05]. 10 animals were used in each group.


## 3.4. Effect of Board-Hole Test

The effect of CS on the board-hole
test is shown in Figure7. At the doses of 300, 600, and 100 mg/kg, IP, a
significant increase in the amount of head-dipping behavior was shown
*[F
(1.13) = 5.7;
P<.001].Figure 7
Time spent in head-dip registered in a 5-minute session in
the board-hole test performed 1 hour after administered do control, diazepam
(2.5 mg/kg), and CS. In this test, all doses used showed a very significant
effect on the control and similar to diazepam*[F
(1.13) =  5.7; P<.01]. 10
animals were used in each group.


## 3.5. Effect of CS on the Elevated Plus-Maze (EPM)

CS in all the doses (300, 600, and
1000 mg/kg, IP) produced anxiolytic-like effects as determined by the
increase in the percentage of open arm entries*[F (1.14) = 5.6; P<.01].
Conversely, the number of entries and the time spent in the closed arms were reduced
by CS treatment [F (1.13) = 5.5; P<.01]  (Figures 8
and 9).Figure 8
Effect of diazepam and of CS on the values of time spent in the open arms during 5 minutes. The
data from this figure show that the dose of 1000 mg/kg was not significant in
relation to the vehicle and Diazepam.*[F (1.14) = 5.6; P<.01*P<.01]  and  **[F (1.1) = 55; P<.05]. 10 animals were used in each group.Figure 9
Effect of diazepam and the extract of CS on the values of time spent in the closed arms, during 5 minutes. All doses used in this test had a time of
permanence in the closed arm very significant in relation to the vehicle, and
similar to diazepam*[F (1.13) = 5.5; P<.01]. 10
animals were used in each group.


## 4. Discussion

C. sicyoides is a plant originating from the Dominican Republic
[2]. It is popularly known as “insulina, cipo-pucá, bejuco de porra, bejuco
caro, puci, and anil trepador” [1]. It is used in popular medicine as a diuretic, anti-inflammatory [4], and antidiabetic [5].The aim of this study
was to analyse the behavioral effects of the crude hydroalcoholic extract of
the aerial parts of CS. The results presented here show that CS did not exhibit
toxicity in mice and did not induce any significant changes in several
behavioral and physiological parameters, and showed a slight decrease in
spontaneous locomotor activity and an increase in breathing frequency (data not shown).Treatment with CS
reduced the latency of induction and increased the duration of the
barbiturate-induced sleep (see Figure3) indicating CNS depressant activity,
since sleeping time induced by PBS is related to its central depressant
properties. These finding suggest that C.
sicyoides, administered by the intraperitoneal route, has hypnosedative activity due to the potential of
barbiturate-induced sleep and might probably be due to pharmacokinetic
interactions between CS and PBS through the presence of flavonoids, and mainly
by linalool present in CS leaves [7, 8, 19].In this regard, there
are few reports showing pharmacokinetic interaction of other plant species,
such asSmilax sp., Piper methysticum, among others, with
therapeutic drugs such as diazepam, alcohol, barbiturates, and other psycho
pharmacological agents [30, 31]. PBS is metabolized in the liver by an
oxidative pathway that involves cytochrome P450, NADPH, and molecular
O2 [32]. A hypothesis to explain the enhanced barbiturate-induced
sleep should be possible as an enzymatic inhibition of liver enzymatic systems,
such as CYP 450, by CS, metabolizes intermediate and short-action barbiturates [25, 33]. CS produced a protection against
convulsions induced by PTZ in mice
*[F
(1.6) = 5.7; P<.01]  (see Figure 5).CS also increased
significantly the number of hidden glass marbles*[F (1.14) =
5.8; P<.01], and [F (1.12) = 5.7; P<.05]  (Figure 6). A significant
increase in the exploratory head-dipping behavior was observed after the
treatment with 300, 600, and 1000 mg/kg IP of the CS extract, thus
reinforcing the anxiolytic-like activity
*[F
(1.13) = 5.7; P<.01]  and
**[F (1.12)
= 5.7; P<.05]  (Figure 7). On the other hand, several plants increased exploratory
behavior of open arms in the EPM test and are generally used to diminish
anxiety in folkloric medicine. Among them are Ginkgo biloba, Cassimiroa edulis [29, 33, 34]. In the EPM test, the effect of CS extract at doses of 300 and 600 mg/kg, IP was observed in the time spent in open arms
*[F (1.13) = 5.7; P<.01]  (see Figure 7).The number of entries
and the time spent in closed arms were reduced by the intraperitoneal treatment
with CS (300, 600, and 1000 mg/kg) in comparison to the control values*[F (1.14) = 5.6; P<.01]  and
**[F (1.11) = 5.5; P<.05]  (see Figure 8). The EPM test is designed to
evaluate drugs with anxiolytic-like nonspecific action. Extract or drugs that
increase the time spent in open arms are considered anxiolytic by withdrawal of
fear in the animals. The same happens with time spent in the closed arms, which
are considered to produce fear or anxiety [29].In this study, diazepam
was used as a positive control, and, as expected, it increased the activity in
the open arms of the EPM apparatus, confirming anxiolytic-like actions. The
presence of flavonoids, linalool, andα-tocopherol in C. sicyoides leaves reinforces the anxiolytic-like and
anticonvulsant-like effects of this plant found by us in this study.



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*Source: 274740-2009-03-12.xml*