Hunulard Medicus \t)1. 51. No l. l(nlS Antidiarrhoeal and Neuropharmacological Activities of Avic ennia officinalis Linn. Firoj Ahm ed, l.Z. Shahid, Amina Khatun and Nusrat Subhan Phamracy Discipline, Khulna University, Khulna-9208, Bangladesh. The nrethanolic extract of the leaves ol At,icennia fficinulis Linn. was tested for its antidirrrhocrl and neuropharnracologie ll activiries. Thc cxtract showcd a significant antidiarrhoeal activityagainst castor oil induced diarrhocir in Inicc in which it decreasctl the frcquency of'defccationand incrcascd nreanlatent period at the dose of 500 mg/kg btxly wcight. Morcovcr. it potcntirtcd thc pcntobarbital induccd slccping tinre in micc at the doseof 5il) mg/kg body weight,and clecrcascd thc Irutttbcr of httle s crossctl l'rorn onc chambcr in the holc cross tcst and decreascd the head dip rcsponses. The ovcrall rcsults tendto sugtlcst the antidrarrhocll and central ncrvous svstemdcpressant activitiesof the cxtract. Keywords: Avit'urttiu tfficinalis; Antidiarrhoeal activity; Neuropharmacological activity. Introduction Avicennia fficinalis Linn. (Family: Avicenniaceae; synonym - Avicennia tonrcntosu Willd.),commonly knou'n as Boen or Kalu baen, is a long tree widely distributed in Coast forests of Bengal,Myanmar, nlangrove forests ol China ancl Japan. Its bark and leaves are usedin the treatment of asthma, diabetes, rheumatism (Balasooriya et ai 1982). No biological work has been reported on Avicennia officinalis. The objective of the present study rvasl,' investigate the antidiirrrhoeal and neuropharmacological activities of the crude ntethancllic extract of the lcaves oi Avicetmicttffic'inalis (A. officinalis). Nlaterials and lVlethods Preparation of Plant Extruct A. ffic'inali.r was collectedfronr the Sundarbans' Mangrove Forests and was taxttnomically' identi{'ied br tl : experrs at the Bangtadesh National Herbarium (accession no.30556). About 400grn of powdered leaves \\.t\ I.1N.- in a clean, flat-bottctnted glass container (4 l) and soaked in 1300 ml of solvent. The cttntainer u'ith its coTltcrll. .r-' sealed and kept for a periodof 7 days accompanying occasional shaking and stirring. The *holc rnirtLrtr'i-: underwent a coarse filtration by a piece of clean, whitecotton material followed by a filtration throLrgh \l'huttl ,,i :r : .-' paper and the filtrate thus obtained was concentrated by usinga rotaryevaporator (Bibby RE200. Stcrilin I:-: :. to get the crude extract. Phyt oc h entic ul An alysis The crude extract was subjected to preliminary phytochemical screening for the detectit,it,': ;r... -' groups as alkaloids, flavonoids, gums, reducing sugars, saponins, steroids and tannins (Erlttts. l'lr" I: :..- (q,/r,) solution of the extract in methanol was taken unless otherwise mentionecl in inditrdu.ri t:.: