Mallaw (Malva sylvestris L.) is a medicinal plant who is traditionally being used as an antiulcer, laxative and anti-hemorrhoid, besides of its culinary use as a food in Tunisian cuisine. The present study was carried out to evaluate the protective effect of Malva sylvestris aqueous extract (MSAE) on constipation- induced by loperamide in male Wistar rats.

Rats were divided into six groups of six animals each: Control, Loperamide (LOP), LOP+ yohimbine (2mg/kg b.w, i.p.) and LOP+ various doses of MSAE (100, 200 and 400mg/kg b.w, p.o.). The laxative activity was determined based on the weight, frequency and water content of the feces matter. The effects of MSAE were also evaluated on normal gastric emptying and gastro-intestinal transit as well as loperamide-induced serum metabolic parameters changes and colon oxidative stress.

The MSAE (100, 200 and 400mg/kg; b.w, p.o.), significantly reduced loperamide-induced constipation in a dose-dependent manner. Our extract improves also the gastrointestinal motility, mitigates colon lipid peroxidation and H₂O₂ colon overload, preserve normal antioxidant enzymes activities and non-enzymatic antioxidant levels, as well as provides stability of lipid profile, hepatic (AST and ALT) and renal (urea and creatinine) levels changed by loperamide intoxication.

We suggests in the present work that MSAE had a potent effect against Loperamide- induced constipation through in part to an increase of gastrointestinal motility, astimulation of water intestinal secretion as well as its antioxidant properties.