Hypericum Perforatum L. Hypericaceae/Guttiferae Sunflower, Olive and Palm Oil Extracts Attenuate Cold Restraint Stress - Induced Gastric Lesions

Three Hypericum perforatum L., Hypericaceae (St. John's Wort) oil extracts (HPE) were prepared according to the prescriptions from traditional medicine - fresh flowering tops were macerated in three different vegetable oils: sunflower (E1), olive (E2) and palm oil (E3) for 40 days, exposed to the sunlight. The aim of the study was to investigate the gastroprotective activity of the obtained extracts in respect to their quercetin content. HPLC analysis confirmed the presence of quercetin in all of the investigated HPEs, but in different amounts: 15.1, 5.8 and 21.7 mu g/mL in E1, E2, and E3, respectively. Gastroprotective activity was evaluated using cold-restraint stress (CRS) induced rat gastric mucosa lesions test. All of the HPEs showed gastroprotective activity, which was close to that achieved by the one of the most studied anti-ulcer flavonoids, quercetin [percentages of inhibition of ulcer index (UI) were 35, 62 and 40 % in E1, E2 and E3, respectively]. Contrary to the lowest quercetin content, HPE prepared with olive oil (E2) offered the highest protection against gastric damaging action of CRS. It may be assumed that this is due to other constituents of E2, which probably play an additional role in complex gastroprotective activity.