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Please use this identifier to cite or link to this item: http://hdl.handle.net/123456789/2013

Keywords: Gastroprotective, propolis, EEP, ulcer index, alcohol, indomethacin, gastric lesion
Copyright: Aug-2007
Date Added: 30-Apr-2012
Abstract: Gastric hyperacidity and peptic ulcer are very common causes of human suffering in this era of globalization. Treatment of peptic ulcer is targeted at either counteracting aggressive factors or stimulating the mucosal defenses. Natural products from bees and plants are recently becoming the focus of attention as preventive medicine in providing protection against acute and chronic gastric lesions. In the present study, the gastroprotective effects of ethanol extract of propolis (EEP) from Ethiopian central high land was evaluated against ethanol and indomethacin-induced gastric ulcers in mice. Half kilogram of propolis was soaked in 70% ethyl alcohol for two weeks at room temperature with intermittent shaking twice a day. After evaporating the alcohol and lyophilizing the residue to dryness, a gummy consistent crude propolis extract of 35.35g yield was obtained. The phytochemical screening with thin layer chromatography (TLC) and gas chromatography-mass spectrometry (GC/MS) showed that the major phyto-constituents of the extract were amryn type triterpenic alcohols (26.2%), sugars (24.9%) and fatty acids (7.5%), with significant amount of aromatic acids, esters and other alcohols including diterpenic alcohol. Swiss albino mice of 24-32g body weight were fasted for 24hours and pretreated with varying doses of EEP or standard drugs (omeprazole or cimetidine) fifty minutes before ulcer induction either with alcohol or indomethacin. In alcohol-induced ulcers, EEP at doses of 25, 50 and 100mg/kg significantly reduced lesion index and number of the total lesions (P<0.05) in the glandular area of the stomach. In indomethacin-induced ulcers, the same dose of EEP as for alcohol- induced ulcers also significantly decreased ulcer index and number of the total lesions (P<0.05) in the glandular region of the stomach compared to the control. In both cases, the extract was shown to reduce gastric lesions in a dose-dependent manner. The intraperitoneal (i.p) pretreatment with indomethacin one hour before the extract did not affect the gastroprotective effects of the EEP on alcohol-induced ulcers. The histological observations in the glandular area of the stomach also revealed that severe hemorrhagic patchy lesions occurred covering most parts in the absence of EEP. Mucosal epithelial damage was confirmed by microscopic observation of the Hematoxylin-eosin fixed tissue taken from the same glandular area of the stomach. The gastroprotective mechanism of EEP could be due to its antioxidant effects, and/or its film forming properties. Further investigation on the chemical composition and the biological activities of Ethiopian propolis from different agro-ecological zones are recommended.
Description: This thesis has no Advisor
URI: http://hdl.handle.net/123456789/2013
Appears in:Thesis - Medical Physiology

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