Antispasmodic and anti-diarrhoeal effect of Satureja hortensis L. essential oil.

Satureja hortensis L. (Lamiaceae) is an annual herb that is used in the traditional medicine of Iran for treating stomach and intestinal disorders. The antispasmodic activity of S. hortensis essential oil (SHEO) was assessed on contractions of isolated ileum, induced by KCl and acetylcholine, and compared with the effect of atropine and dicyclomine. SHEO inhibited the response to 80 mM KCl in a concentration-dependent manner (pD(2)=1.55+/-0.09 microg/ml; this is negative log concentration of SHEO causing 50% of maximum inhibition) and attenuating the maximum inducible response of acetylcholine concentration-response curve. Effect of SHEO on KCl was similar to that of dicyclomine. Dicyclomine (3.46 and 34.6 ng/ml) also reduced the response to acetylcholine on rat isolated ileum without altering the maximum response and shifted the acetylcholine concentration-response curve to the right by 16-fold at 34.6 ng/ml (100 nM) bath concentration, while atropine only inhibited the response to acetylcholine. This study shows that SHEO is a relaxant of rat isolated ileum. In addition to antispasmodic activity in vitro, essential oil of this plant at a dose of 0.1 ml/100 g inhibited castor oil induced diarrhoea in mice. As the inhibition of contractile overactivity of the ileum is the base of the treatment of some gastrointestinal disorders such as colic, SHEO may have clinical benefits for treatment of these conditions.

Effects of extract and essential oil of Rosmarinus officinalis L. on TNBS-induced colitis in rats.

Rosmarinus officinalis L. (Family Lamiaceae) popularly named rosemary, is a common household plant grown around the world, including Iran. Rosemary aerial parts are used as flavoring agent in foods, beverages, and cosmetic preparations and have various traditional uses in ethnomedicine including: analgesic, anti-inflammatory, anti-rheumatic, spasmolytic, carminative and choleretic applications. This study was carried out to investigate the effects of rosemary leaves hydroalcoholic extract (RHE) and essential oil (REO) in a well-defined model of experimental colitis induced by trinitrobenzene sulfonic acid (TNBS) in rats. Different doses of RHE (100, 200 and 400 mg/kg) and REO (100, 200 and 400 µl/kg) were administered orally and intraperitoneally (100, 400 mg/kg and 100, 400 µl/kg) to male Wistar rats (n=6), 6 h after colitis induction and continued for 5 days by intracolonic instillation of 0.25 ml TNBS (80 mg/kg)/ethanol 50% v/v. Wet colon weight/length ratio was measured and tissue damage scores as well as indices of colitis were evaluated both macroscopically and histopathologically. RHE and REO at all test doses used were effective to reduce colon tissue lesions and colitis indices while greater doses were significantly effective to diminish histopathologic parameters irrespective to the route of administration. Administration of oral prednisolone, Asacol(®) (mesalazine microgranules) and parenteral hydrocortisone acetate were effective to reduce colon tissue injures as well. These data suggest that RHE and REO are both effective to possess anti-colitic activity, and reinforce the use of this plant as a remedy for inflammatory bowel diseases in traditional medicine.