Gastrointestinal Stimulant Effect of Urginea indica Kunth. and Involvement of Muscarinic Receptors Saima Abbas, 1 Samra Bashir, 1,2 Aslam Khan, 2 Malik Hassan Mehmood 2 and Anwarul Hassan Gilani 2 * 1 Department of Pharmacy, Bahauddin Zakariya University, Multan, Pakistan 2 Natural Product Research Unit, Department of Biological and Biomedical Sciences, the Aga Khan University Medical College, Karachi 74800, Pakistan Urginea indica Kunth. (Family; Liliaceae) was studied for its gastrointestinal stimulant effect to rationalize the traditional medicinal uses as a digestive aid, stomachic and laxative. The crude aqueous-methanol extract of Urginea indica bulb (Ui.Cr) was tested on mice and isolated gut preparations. Ui.Cr, which was tested positive for alkaloids, tannins and coumarins, increased faecal output and accelerated charcoal meal transit in mice (6– 12 mg/kg, p.o.), similar to that caused by carbachol (10 mg/kg). Ui.Cr (0.01–1 mg/mL) caused a spasmogenic ef- fect in guinea-pig ileum that was reproduced in rabbit jejunum (0.01–0.3 mg/mL) followed by relaxation at a higher concentration. Like carbachol, the stimulant effect of Ui.Cr was blocked by atropine, suggesting the acti- vation of muscarinic receptors mediating the prokinetic effect. Ui.Cr (0.01–5.0 mg/mL) also inhibited K + (80 mM)-induced contraction in rabbit jejunum and shifted the Ca 2+ concentration-response curves to the right, similar to verapamil, a standard calcium channel blocker. These data, indicating the presence of a gastrointestinal stimulant effect in Urginea indica possibly mediated through a cholinergic mechanism, provide a rationale for the use of Urginea indica in indigestion and constipation. The presence of a calcium antagonist effect in the plant may help to alleviate untoward effects of the plant that may result from an excessive increase in gut motility. Copyright © 2011 John Wiley & Sons, Ltd. Keywords: Urginea indica; gut stimulant; cholinergic; mice; guinea-pig ileum; rabbit jejunum. INTRODUCTION Digestive diseases, affecting 70% of the general popula- tion, are the cause of considerable social and economical impact (Ouyang and Chen, 2004). Constipation, diarrhea and dyspepsia, in particular, are commonly prevailing disorders (Mehmood et al., 2010). Medicinal plants are usually preferred to treat these gastrointestinal disorders, because they contain multiple constituents with effect enhancing and/or side-effect-neutralizing potential (Gilani and Rahman, 2005), and, hence, are considered relatively safe in prolonged use. Seed husk of Plantago ovata (psyllium husk), for example, is a widely used remedy equally popular among traditional healers and modern physicians for digestive disorders and has been proven effective in relieving both constipation and diarrhea (Mehmood et al., 2010) Urginea indica Kunth. (Syn: Scilla indica Roxb), locally known as ‘Jungli-piyaz’ and commonly as ‘In- dian squill’, belongs to the family Liliaceae. The plant is found in drier sub-Himalayan tracts of western Himalayas; Bihar, Konkan, and on the Coromandel Coast (Kapoor, 1990). The bulb of Urginea indica is popularly employed as a gastrointestinal stimulant to relieve constipation and indigestion. The plant has also been reported to be used as an anthelmintic, cardiac stimulant, deobstruent, diuretic, emmenagogue and for the treatment of calculous affections, cough, bron- chitis, asthma, paralytic affection, rheumatism, leprosy, skin diseases, internal pain and scabies (Kirtikar and Basu, 1988; Baquar, 1989; Prajapati et al., 2003). Bulbs crushed or sliced are also applied under the sole of the feet to prevent burning sensation (Kapoor, 1990; Usmanghani et al., 1997) and are used externally for removing corns and warts (Kapoor, 1990; Prajapati et al., 2003). The plant has been reported to contain glycosides including scillaren-A and scillaren-B (Prajapati et al., 2003). Urginea indica has been studied for its medi- cinal effect as an antifungal (Shenoy et al., 2006), antiangiogenic and pro-apoptotic (Deepak and Salimath, 2006). Despite its wide medicinal application, Urginea indica has not been studied extensively to evaluate its medi- cinal uses pertaining to the gastrointestinal stimulant effect. This study was therefore undertaken to provide a pharmacological rationale for the use of Urginea indica bulb as a laxative, digestive and stomachic. MATERIALS AND METHODS Plant material and preparation of crude extract. The bulbs of Urginea indica were collected fresh from fields of Mianwali subsequent to the identification of the plant by an expert taxonomist at the Institute of Pure and Applied Biology, Bahauddin Zakariya University, Multan. A specimen of the plant has been deposited at * Correspondence to: Dr Anwarul Hassan Gilani, Professor of Pharmacol- ogy, Department of Biological and Biomedical Sciences, The Aga Khan University Medical College, Karachi-74800, Pakistan. E-mail: anwar.gilani@aku.edu PHYTOTHERAPY RESEARCH Phytother. Res. 26: 704–708 (2012) Published online 18 October 2011 in Wiley Online Library (wileyonlinelibrary.com) DOI: 10.1002/ptr.3634 Copyright © 2011 John Wiley & Sons, Ltd. Received 1 June 2011 Revised 1 July 2011 Accepted 11 July 2011