Gastroprotective activity of Hypericum perforatum extracts prepared with different vegetable oils

Oleum Hyperici is one of the oldest remedies that has been traditionally used for a great number of indications: for topical treatment of wounds, burns and chemorroides and for orally treatment against ulcerations. In our recent study three Hypericum perforatum (St. John's wort) oil extracts (HPE) were prepared according to prescription from traditional medicine: fresh flowering tops of the plant were macerated in oil for 40 days exposed to the sunlight. The oils used as extragens were: sunflower, olive and palm oil (plant material:extragens was 1:5). Identification and quantification of quercetin in all obtained extracts was carried out by HPLC analysis (5.8, 15.1 and 21.7µg/ml in oliva, sunflower and palm oil, respectively). Furthermore, the protective activity of the prepared HPEs in rat gastric mucosal injury induced by cold restraint stress (CRS) was investigated. The results of the present study demonstrated that all of three St. John's wort oil extracts offered significant protection against gastric damaging action of CRS in rats, and that this effect was close to that achieved by the one of the most studied anti-ulcer flavonoid, quercetin. Among them the extract prepared with olive oil showed the highest gastroprotective activity, despite of the lowest quercetin content (percentages of inhibition expressed as ulcer index (UI) were 35, 60 and 40 in olive, sunflower and palm oil extracts, respectively). This indicates that besides quercetin, other constituents of St. John's wort oil extracts probably play additional role in complex gastroprotective activity.

Acknowledgements: The authors wish to thank Serbian Ministry of Science for financial support project number TR 20137