Study on anti-anxiety effect of willughbeia cochinchinensis in scopolaminc-administered mice by using open field test – Nguyen Tat Dinh

Journal of military pharmaco-medicine no5-2018 170 STUDY ON ANTI-ANXIETY EFFECT OF WILLUGHBEIA COCHINCHINENSIS IN SCOPOLAMINC-ADMINISTERED MICE BY USING OPEN FIELD TEST Nguyen Tat Dinh*; Cao Tien Duc*; Le Van Quan** SUMMARY Objective: To investigate effects of Wullughbeia cochinchinensis to ameliorate disorders in anxiety-like behaviors of mice. Subjects and methods: In the present study, 50 Swiss mice were induced anxiety-like behaviors by scopolamine. Behaviors of mice treated with and without Wullughbeia cochinchinensis at doses of 100 mg/kg, 150 mg/kg and 200 mg/Kg and/or scopolamine were tested using the open field test. Results: Wullughbeia cochinchinensis at dose of 150 mg/kg and 200 mg/kg induced a significant increase in time spent, number of entries and travel distances in the center area of open field in animals with scopolamine-induced anxiety-like behaviors. Conclusion: Wullughbeia cochinchinensis 150 mg/kg and 200 mg/kg might ameliorate deficits in anxiety like symptoms in experimental animals. * Keywords: Anxiety, Mice; Willughbeia cochinchinensis. INTRODUCTION Anxiety is one of the common symptoms in mental disorders such as depression, phobia, etc. In a recent study, it has suggested that 33.7% of the population are affected by an anxiety disorder during their lifetime [1]. Furthermore, ratio of females with anxiety disorder is higher than this of male with this symptom [2]. In treatment, benzodiazepines have been suggested to be effective to anxiety disorders. However, these drugs might induce drug dependence when they are used a long time [3]. Thus, it is necessary to investigate new natural plants or drugs for treating anxiety disorders. It has suggested that anxiety-like disorders might relate to activities of achetylcholine. Thus, scopolamine, an antagonist to acetylcholinergic receptors, might be used to induce anxiety-like behaviors in experimental animals [4]. In the present study, we used this animal model to investigate effects of a new natural plant, Wullughbeia cochinchinensis (WC) to meliorate deficit in anxiety-like behaviors in mice. SUBJECTS AND METHODS 1. Subjects. 50 Swiss mice (150 - 250 g body weight) were used in the present study. Animals were housed in individual cages, maintained in controlled temperature and 12 h light/dark cycles with free access to water and food. * ** Corresponding author: Le Van Quan (@gmail.com) Date received: 26/02/2018 Date accepted: 30/05/2018 Journal of military pharmaco-medicine no5-2018 171 Animals were separated randomly into 5 experimental groups, 10 mice for each group: group 1 (control group): mice were ip and p.o treated saline; group 2 (scopolamine group): mice were i.p treated scopolamine 1.5 mg/Kg and p.o treated saline at 0.1 ml/10 g; group 3, group 4 and group 5 (WC groups): mice were i.p injected scopolamine 1.5 mg/Kg and p.o WC 100 mg/Kg, 150 mg/Kg and 200 mg/Kg, respectively. WC and saline were orally administered at 60 minutes and scopolamine and saline were i.p injected at 30 minutes before the behavioral task. The present study was conducted at Department of Physiology, Vietnam Military Medical University. All procedures were performed in accordance with the Animal Center Guidelines for the Care and Use of Laboratory Animals at the Vietnam Military Medical University. 2. Materials. - WC was isolated by Department of Pharmacy, Hochiminh City University of Medicine and Pharmacy and was supplied in power form. WC power was dissolved in saline using a magnetic stirrer. - Open field box was a square box (40 x 40 x 60 cm), covered with polypropylene sheets inside the wooden box. In the present study, the open field was separated into two areas: a center area and a periphery zone (figure 1). Figure 1: Open field box. 3. Methods. * Open field test: 60 minutes after drug treatments, mice were placed in the center of an open field box. Animals were allowed to free explore inside open field box for 5 minutes. Behaviors of animals were recorded using a digital video system. Data was analyzed offline by ANY-maze software (Stoelting Co., Wood Dale, IL, USA). * Research indicators: To investigate anxiety-like behaviors in mice, we concentrated to analyze activities of animals in the center area of the open field apparatus. These were: - Time spent in the central zone (s). - Numbers of entries into the central area. - Travel distances in the central area (m). * Data analysis: Time spent in the central area; numbers of entries in the central zone and travel distances in the center area were analyzed by one-way analysis of variance (ANOVA) followed by the Tukey’s post- hoc test for multiple comparisons, using SPSS 19.0. Results were considered to be statistically significant at p < 0.05. All results were expressed as mean ± SEM. Journal of military pharmaco-medicine no5-2018 172 RESULTS 1. Time spent in the central area of the open field. Figure 2: Time spent in the center area. Time spent in the central area is used to assess exploring abilities as well as anxiety-like behaviors of mice. In the fig. 2, time spent in the central area of animals treated by scopolamine was significant shorter than this of animals treated by saline (p < 0.05). After animals treated by WC, there were gradual increases in time spent in the central area. However, significant differences were found only in animals treated by WC at doses of 150 mg/kg and 200 mg/kg (p < 0.05). 2. Numbers of entries to the central area. Figure 3: Entries to the central area. Journal of military pharmaco-medicine no5-2018 173 Fig. 3 indicated results of entries of mice into the central area. Results showed that number of entries into the central area of mice treated by scopolamine was significant lower than this of mice treated by saline (control group) (p < 0.01). Furthermore, there were gradual increases in entries of mice into central areas following treatments of WC at doses of 100 mg/kg; 150 mg/kg and 200 mg/kg. However, there were significant differences in numbers of entries into the central area of mice treated by WC at doses of 150 mg/kg and 200 mg/Kg (p < 0.05). 3. Travel distances in the central area, Fig. 3 showed travel distances in the central areas of mice in experimental groups. Results showed that mean travel distance in the central area of scopolamine-treated mice was significant shorter than this of saline-treated mice (p < 0.01). After treatments of WC 60 minutes, travel distances in the central area of mice increased gradually. However, travel distances of mice in the central areas increased significantly in groups WC 150 and WC 200 only (p < 0.01). Figure 4: Travel distances in the central area. DISCUSION Open field is one of the common behavioral tests which are employed to investigate anxiety-like disorders in rodent animals. In the open field test, the time animals spent and number of entries to the center of arena is often used to measure anxiety-related behaviors in mice. In general, due to life characteristics of mice, they avoid the center of open field arena. Increases in time spent and numbers of entries into the central areas of the open fields might indicate a decrease in anxiety behaviors [5]. Journal of military pharmaco-medicine no5-2018 174 In the present study, we found evidence of improving anxiety disorder effect of WC. These were: treatments of WC at doses of 150 mg/kg and 200 mg/kg induced increases in time spent, numbers of entries and travel distances in the center of open field arena. These results are consistent with previous studies which have concentrated to investigate anxiety disorders in mice. Anchan et al showed that GPR30 activation decreases anxiety in the open field which was expressed by a greater distance and higher number of entries into the central area in the open field [6]. Similarly, by the some way, they have demonstrated that γ-aminobutyric acid transporter-1 also is involved in decrease of anxiety like behaviors in mice [7]. From above results, our study showed a direct evidence for effects of WC to decreasing anxiety like behaviors in mice. CONCLUSION In the present study, we investigated anti-anxiety effect of WC in mice. We found that: After treatments of WC at doses of 150 mg/kg and 200 mg/kg increase in time spent in the center of arena, greater travel distances and higher numbers of entries into the central of open field area. These results provided new evidences for using new natural plants in treatments for anxiety disorders in humans. REFERENCES 1. Bandelow B. Epidemiology of anxiety disorders in the 21 st century. Dialogues Clin Neurosci. 2015, 17 (3), pp.327-335. 2. McLean C.P, Asnaani A, Litz B.T, Hofmann S.G. Gender differences in anxiety disorders: Prevalence, course of illness, comorbidity and burden of illness. J Psychiatr Res. 2011, 45 (8), pp.1027-1035. 3. Starcevic V. Benzodiazepines for anxiety disorders: maximizing the benefits and minimizing the risks. Advances in Psychiatric Treatment. 2012, 18 (4), pp.250-258. 4. Rodgers R.J, Cao B.J, Dalvi A, Holmes A. Animal models of anxiety: an ethological perspective. Braz J Med Biol Res. 1997, 30 (3), pp.289-304. 5. Walsh R.N, Cummins R.A. The open- field test: a critical review. Psychological Bulletin. 1976, 83, pp.482-504. 6. Anchan D, Clark S, Pollard K, Vasudevan N. GPR30 activation decreases anxiety in the open field test but not in the elevated plus maze test in female mice. Brain Behav. 2014, 4 (1), pp.51-59. 7. Gong X, Shao Y, Li B, Chen L, Wang C, Chen Y. γ-aminobutyric acid transporter-1 is involved in anxiety-like behaviors and cognitive function in knockout mice. Exp Ther Med. 2015, 10 (2), pp.653-658.