Anxiety disorders, the most common psychiatric illnesses in the general population, present in 15–20% of primary care patients. Anxiety, defined as a subjective sense of unease, dread, or foreboding, can indicate a primary psychiatric condition or can be a component of, or reaction to, a primary medical disease. Approximately one-third of patients presenting with anxiety have a medical etiology for their psychiatric symptoms, but an anxiety disorder can also present with somatic symptoms in the absence of a diagnosable medical condition1, almost inevitable component of many medical and surgical conditions.2
Most commonly employed pharmacotherapies for common clinical anxiety disorders are anxiolytics like benzodiazepines(diazepam) and other than benzodiazepines like Azopirones(Buspirone, gepirone, ispapirone), antidepressants like Selective Serotonin Reuptake Inhibitors (fluoxetine, sertraline), tricyclic antidepressants (Amitriptyline, imipramine) are used.1
Anxiety disorders may be acute and transient, or more commonly, recurrent or persistent. Chronic benzodiazepine use poses a risk for development of dependence and abuse. Withdrawal symptoms include dysphoria, irritability, sweating, unpleasant dreams, tremors, anorexia, and faintness or dizziness also may occur. Therapeutic doses can further compromise respiration in patients with chronic obstructive pulmonary disease (COPD) or obstructive sleep apnea (OSA). A variety of allergic, hepatotoxic, and hematologic reactions to the benzodiazepines may occur.2
Selective serotonin reuptake inhibitors(SSRIs) have side effects like insomnia, sexual dysfunction, can affect plasma levels of other medicines (except sertraline); Tricyclic antidepressants(TCAs) have side effects like anticholinergic symptoms (dry mouth, tachycardia, constipation, urinary retention, blurred vision); sweating; tremor; postural hypotension; cardiac conduction delay; sedation; weight gain.1
This has prompted many researchers to evaluate new compounds in the hope of identifying other anxiolytic drugs with fewer unwanted side effects. Hence search for better anxiolytics continues.
Ethanolic extract of Nymphaea alba linn possesses anxiolytic and muscle relaxant properties. Thus Nymphaea alba linn has potential clinical application in the management of anxiety and muscle tension disorders.3
Aim of this work is to evaluate the anxiolytic effect ethanolic extract of Nymphaea alba linn and to compare with that of diazepam.
6.2 Review of literature :
Nymphaea alba Linnaeus (family Nymphaeaceae), commonly known as white water lily in English and kumuda in Sanskrit, is an aquatic herb with perennial rhizomes or rootstocks anchored with mud. It is globally distributed in Europe, North Africa, Southwest Asia, India, China and Russia. It is rich in phytochemicals such as tannic acid, gallic acid, alkaloids, sterols, flavonoids, glycosides, hydrolysable tannins and high molecular weight polyphenolic compounds.4 All the parts of the plant have medicinal uses in traditional system of medicine. It is used as an aphrodisiac, anodyne, antiscrophulatic, astringent, cardiotonic, demulcent, sedative and anti-inflammatory. Further it also produces calming and sedative effects upon the nervous system and is useful in the treatment of insomnia, anxiety and similar disorders.5, 6 Its anticarcinogenic action and inhibition of renal oxidative stress and hyper proliferative response were reported.7, 8 However so far there are not many studies done on anxiolytic effect of Nymphaea alba. Therefore, to confirm the anxiolytic potential of Nymphaea alba
(N. alba) we undertook this study using albino rats.
It is an established fact that the anxiolytic, anticonvulsant, muscle relaxant, and sedative-hypnotic actions of the BZDs is due to binding and modulating the GABA-BZD receptor-chloride channel complex. 2, 12 Phytochemical tests of N. alba revealed the presence of flavonoids, tannins, and saponins. The anxiolytic action of N. alba could be due to the binding of any of these phytochemicals to the GABA A -BZD complex. In support of this, it has been found that flavones bind with high affinity to the BZD site of the GABA A receptor.9, 10, 11 The anxiolytic effect of N. alba may also be due to antagonistic effect on the 5-HT1B receptor or agonistic effect on the 5-HT1A receptor.10,11
2) To compare the antianxiety activity of ethanolic extract of N.alba with diazepam.
MATERIAL AND METHODS
7.1 Source of data :
Animals: Albino rats inbred in central animal house of department of Pharmacology, JJM Medical College, Davanagere under suitable conditions of housing, temperature, ventilation and nutrition.
Chemicals, drugs and apparatus :
1) Distilled water
2) 1% gum acacia
3) Ethanolic extract of N.alba(100,200mg/kg)
4) Tab.Diazepam (5mg)
5) Elevated plus maze
7.2 Method of collection of data (including sample procedure if any):
A total of forty eight male albino rats (N=48) will be divided into 2 groups, group I and group II, each group containing twenty four animals(n=24) each. Animals will be randomly housed at an ambient temperature and humidity, with a 12hour light: 12hour dark cycle. The animals will have free access to standard pellet and water.
1. Male albino rats weighing between 100-200g.
2. Age between 3-4months.
3. Healthy with normal behavior and activity.
1. Animals weighing <100 and >200g.
2. Age less than 3months or more than 4months.
3. Within 21days of use for other studies.
4. Female rats.
A total of forty eight male albino rats (N=48) will be divided into 2 groups, group I and group II, each group containing twenty four animals (n=24) each. Again each group is divided into 4groups group A, B, C, D and each containing 6 animals and assigned as control, standard and test group as shown below. Each drug solution will be prepared freshly just before the administration. In all the groups drugs will be administered orally 60minutes prior to tests.
Group A: Control group: Receiving 10ml /kg of distilled water.
Group B: Standard group: Receiving 1mg/kg Diazepam diluted in distilled water.
Group C: Test group: Receiving 100mg/kg of ethanolic extract of N.alba in distilled water.
Group D: Test group: Receiving 200mg/kg of ethanolic extract of N. alba in distilled water.
The wooden maze will consist of two open arms (50cmX10cm) and two closed arms of the same size (with the height of 40cm). The arms of the same type will be opposite to each other, with a central square of 10cm. The maze will be elevated to a height of 50cm above the floor. Rat will be allowed to explore the maze for 5mins.13, 14
1) Total time spent in open and closed arms separately.
2) Total entries in open and closed arms separately.
Group II -Locomotor activity assessment: The locomotor activity was measured using an actophotometer. The movement of the animal interrupts a beam of light falling on a photocell, at which a count was recorded and displayed digitally. Each rat was placed individually in the actophotometer for 10minutes and the basal activity score was obtained. Subsequently, animals were divided into 5groups, each consisting of 6 animals. N. alba extract (100,200mg/kg), vehicle (distilled water), diazepam (1mg/kg) was administered orally and after 60minutes the rats were placed again in actophotometer for recording the activity score. Reduction in activity score% is calculated.14
Locomotor activity score before and after treatment and reduction in activity (%).
Results will be analyzed using one way Analysis of variance (ANOVA) followed by Dunnett’s “t” test.
7.3 Does the study require any investigations or interventions to be conducted in patients or other humans or animals? If so, please describe briefly.
7.4 Has ethical clearance been obtained from your institution in case of 7.3.
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