Research Journal of Phytomedicine 01[01] 2015 www.asdpub.com/index.php/rjp ISSN-XXXX-XXXX (Online) © ASD Publisher All rights reserved. 39 Original Article The anti-depressant and anxiolytic properties of the lyophilized aqueous leaf extract of Mimosa pudica L. (Fabaceae) Gerard Q. De Guzman *1,5,6 , Mafel C. Ysrael 1,2,4 , Aleth Therese L. Dacanay 1,2,4 , Sandra M. Valentin 5 and Grecebio Jonathan D. Alejandro 1,3,4 1 The Graduate School., 2 Faculty of Pharmacy, 3 College of Science and 4 Research Center for the Natural and Applied Sciences, University of Santo Tomas, Espana Blvd., Sampaloc, Manila Philippines 1015 5 College of Pharmacy, Virgen Milagrosa University Foundation, Martin P. Posadas Ave., San Carlos City, Pangasinan, Philippines 2420 6 College of Medicine, Lyceum Northwestern University, Tapuac Dist., Dagupan City, Pangasinan, Philippines 2400 *Corresponding Author Gerard Q. de Guzman, 20 Gloria II Subd., Tandang Sora, Quezon City, M.M., Philippines 1116 Tel. No.: +63 2 454 5353 Fax No.: +63 75 513 2573 Mobile: +63 933 364 4312 E-mail: gerardqdeguzman@yahoo.com Keywords: Mimosa pudica, Anxiolytic, Antidepressant 1. Introduction The leaves of Mimosa pudica L. has been studied for its diuretic, anti-infective, wound healing, antifertility, aphrodisiac ad antivenom properties [1]. A decoction of the leaves exhibit anticonvulsant effects at 1,000 – 4,000 mg/kg in various animal models of seizures although this study did not reveal any mood- stabilizing effects[2]. There is evidence on the antidepressant properties of the aqueous leaf extract at 6 and 8 mg/kg I.P. by the forced-swimming method [3]. However, no studies have been conducted to demonstrate the antidepressant and anxiolytic properties of the lyophilized aqueous leaf extract of M. pudica (LAL- MP). This study seeks to investivate the antidepressant and anxiolytic effects of LAL-MP in different models of depression and anxiety in mice. 2. Materials and Methods 2.1. Harvesting of Plant Material The leaves of M. pudica were harvested in a farm located at San Carlos City, Pangasinan. The plant was authenticated at the Virgen Milagrosa University Foundation Herbarium. Leaves were washed with water to remove dirt and pressed dried in newspapers away from sunlight. Dried leaves were pulverized using a Wiley mill. One kilogram of powdered leaves were extracted by exhaustive cold maceration in a stainless steel percolator with distilled water. Combined aqueous extracts were freeze-dried in a Virtis-201 lyophilizer to yield 158.2 grams (15.8% w/w) of light brown powder which was designated in this study as the LAL-MP. Fluoxetine (i.e., positive control) and LAL-MP were prepared as a 5% (w/v) suspension in 5% (w/v) acacia mucilage. 2.2. Experimental Animals Male Swiss mice weighing at least 20 grams were purchased from the Philippine Food and Drug Authority (Alabang, Muntinlupa City). They were acclimatized at 30 0 C with free access to food and water. Experiments conformed to protocols on the humane handling of laboratory animals as approved by the Institutional Animal Care Use Committee. 2.3. Phytochemical Analysis The LAL-MP was subjected to thin-layer chromatography (TLC) using 1 x 6 cm silica gel 60 F254 TLC plates according to the methods of Guevara (2004)[4]. 2.4. Sample Dosing The LAL-MP was orally adminitered, daily for 14 days, at doses of 50, 100, 200, 300, 400 and 500 mg/kg with 5 mice assigned to each dose. Fluoxetine at 3.3 mg/kg (positive control) and 0.5 mL of 5% acacia mucilage (negative control) were given similarly. During the 14-day dosing, mice were given free access to food and water. The mice were subjected to the forced swimming, tail suspension, elevated plus maze and locomotor activity tests on the 14 th day. Mice were fasted overnight with free access to water before commencing with these tests. 2.5. Forced Swimming Test Mice were dropped individually in an 30 x 20 cms. glass aquarium containing water at a depth of 12 cms. and maintained at 30 0 C. Using a stopwatch, the total mobility time within a duration of 5 minutes (i.e., 300 seconds) was measured [5]. 2.7. Tail Suspension Test Mice were individually suspended at the edge of a table, 50 cms. above the floor, by adhesive tapes placed 1 cm. from the tip of the tail. The mobility time for a 5 minute (i.e., 300 seconds) suspension period was recorded [6]. 2.8. Elevated Plus Maze (EPM) Test The apparatus comprises of 2 open arms (35 x 5 cms.) and 2 closed arms (30 x 5 x 15 cms.) elevated at 12 inches. Mice were individually placed at the center of the maze facing one of the closed arms. The number of entries into the open arms and the % of time spent at the open arms were measured within a 5 minute (i.e., 300 seconds) observation period [7]. Abstract Introduction: This study seeks to determine the antidepressant and anxiolytic properties of the lyophilized aqueous leaf extract of Mimosa pudica (LAL-MP) in mice. Methods: LAL-MP was administered orally to mice at 50 – 500 mg/kg, daily for 14 days, after which mice were individually subjected to the forced swimming (FST) and tail suspension (TST) tests, the elevated plus maze (EPM) model and locomotor activity count. Results: Generally, LAL-MP from 100 to 500 mg/kg exhibit antidepressant and anxiolytic properties in all 4 models of depression and dose levels at 400 and 500 mg/kg were found to be equipotent with the standard drug fluoxetine. Conclusions: This is the first report on the combined antidepressant and anxiolytic properties of LAL-MP.