Indian Journal of Experimental Biology Vol. 47, August 2009, pp. 649-659 Effect of methanolic extract of Pongamia pinnata Linn seed on gastro-duodenal ulceration and mucosal offensive and defensive factors in rats T Prabha a , M Dorababu a , Shalini Goel b , P K Agarwal a , A Singh a , V K Joshi c & R K Goel a* Departments of Pharmacology a & Dravyaguna c Institute of Medical Sciences, Banaras Hindu University, Varanasi 221 005, India & Department of Pathology b Melaka Manipal Medical College, Manipal 576 102, India Received 21 November 2008; revised 20 April 2009 Pongamia pinnata has been advocated in Ayurveda for the treatment of various inflammatory conditions and dyspepsia. The present work includes initial phytochemical screening and study of ulcer protective and healing effects of methanolic extract of seeds of P. pinnata (PPSM) in rats. Phytochemical tests indicated the presence of flavonoids in PPSM. PPSM when administered orally (po) showed dose-dependent (12.5-50 mg/kg for 5 days) ulcer protective effects against gastric ulcer induced by 2 h cold restraint stress. Optimal effective dose of PPSM (25 mg/kg) showed antiulcerogenic activity against acute gastric ulcers (GU) induced by pylorus ligation and aspirin and duodenal ulcer induced by cysteamine but not against ethanol-induced GU. It healed chronic gastric ulcer induced by acetic acid when given for 5 and 10 days. Further, its effects were studied on various parameters of gastric offensive acid-pepsin secretion, lipid peroxidation (LPO) and nitric oxide (NO) and defensive mucosal factors like mucin secretion and mucosal cell shedding, glycoproteins, proliferation and antioxidants; catalase (CAT), superoxide dismutase (SOD) and glutathione (GSH) levels. PPSM tended to decrease acid output and increased mucin secretion and mucosal glycoproteins, while it decreased gastric mucosal cell shedding without any effect on cell proliferation. PPSM significantly reversed the increase in gastric mucosal LPO, NO and SOD levels caused by CRS near to the normal level while it tended to increase CAT and GSH level decreased by CRS and ethanol respectively. Thus, the ulcer protective effects of PPSM may be attributed to the presence of flavonoids and the actions may be due to its effects both on mucosal offensive and defensive factors. Keywords: Acid secretion, Antioxidants, Free radicals, Gastro-duodenal ulcers, Mucosal defense, Pongamia pinnata Pongamia pinnata (L) Pierre (Leguminosae, Papilionoidae, Syn. P. glabra Vent), commonly called Karanj in Hindi, and Karanja, Maktamala or Gaura in Sanskrit and an Indian beech in English, is a medium sized glabrous tree that grows on moist environment along rivers or sea coast all over India and further, distributed eastwards mainly in the littoral regions of South Eastern Asia and Australia 1 . Different parts of the plant have been recommended in Ayurvedic literature as a remedy for various ailments. P. pinnata roots have been described as a useful remedy for foul ulcers, fistulous sores, gonorrhoea, urethritis etc 2 . The seeds and seed oil have been used for treating various inflammatory and infectious diseases such as leucoderma, leprosy, lumbago and rheumatism 3 . The ulcer protective and healing effects and anti- inflammatory activity of alcoholic extract of P. pinnata seeds 4 and root 5-7 have been reported. The ulcer protective effect in P. pinnata root seemed to be due to augmentation of defensive mucosal factors 7 . Protective role of ethanolic extract of P. pinnata root in ischemia-reperfusion injury and cerebrovascular insuffieciecy states provided additional evidence concerning the anti-oxidative stress and cognition- enhancing property of P. pinnata 8 . Flowers of the plant are rich in bioflavonoids and extensively used in various skin diseases, diabetes and renal disorders 9 . P. pinnata has been reported to contain a large number of furanoflavonoids, e.g. karanjin, pongapin, kanjone, pongamol and pongaglabrone, along with a number of simpler flavonoids and lipid like arachidonic acid 10,11 . Peptic ulcers occur when there is an imbalance between offensive and defensive mucosal factors 12 . Ulceration in the mucosa can be because of either breakdown of mucosa with the development of surface defects or failure of restitution of mucosal __________________ *Correspondent author Telephone: 91-0542-2307522; Fax: 91-0542-2367568 E-mail: rkgoel_bhu@yahoo.co.in