Preventive Effect of Thuja occidentalis (Linn) on Gastric Ulcer - a Novel Role of Free Radical Scavenger

In this study, 95% ethanolic extract of Thuja occidentalis Linn (TOE) was evaluated for its anti-ulcer potential by using hard liquor (42.8 % v/v ethanol, 1 ml/150 g body weight) and aspirin (200 mg/kg) induced gastric ulcer models on rats, where oral administration of 200 and 400 mg/kg of TOE showed significant (p<0.001) ulcer protective effect on both the models in a dose dependent fashion. The TOE was also evaluated for its in-vitro free-radical scavenging activity and anti-inflammatory activity. The studies showed significant (p<0.001) free radical scavenging activity of TOE, when compare to control, whereas TOE failed to exhibits any significant (ns p>0.05) anti-inflammatory activity on Carrageenan - induced paw oedema and Cotton pellet granuloma models. Since the extract fail to show significant anti-inflammatory activity, the inhibitory role on prostaglandin synthesis and over production of leukotriene may be ruled out, so we can suggest that gastro-protective activity against aspirin induced ulcer by inhibiting the back diffusion of H⁺ ions. However, further studies are needed to confirm this hypothesis. On the basis of these investigations, we may partially conclude that ulcer-protection may be due to free radical scavenging activity of TOE and TOE could be a potent antiulcer agent for next generation.