Pharmacological and analytical comparison of the wound healing effect of the hypericum perforatum L. oleates prepared by sun maceration technique in different fixed oils

St.John's wort (Hypericum perforatum L.) has been recognized as one of the most popular medicinal plants worldwide. Among a wide range of healing benefits wound healing effect of its oleates in various edible fixed oils, particularly in raw olive oil, have been used traditionally for centuries externally in wound healing (wounds, scars, etc.) or orally for the treatment of peptic ulcer. Although the wound healing effect of various types of H. perforatum oleates prepared in edible fixed oils, i.e., in olive (Olea europaea) oil, sesame (Sesamum indicum) seed oil, sunflower (Helianthus annuus) oil, and black seed (Nigella sativa) oil, have been proven both by experimental and clinical studies, efficiency of these oleates in wound healing has not been comparatively investigated so far. This experimental study aimed to reveal the wound healing potencies of H. perforatum oleates in various edible oils (olive oil, sesame seed oil, sunflower oil, and black seed oil) comparatively, both in analytical and pharmacological means. Firstly, quality specifications of the edible fixed oils used in maceration were analyzed by GC-MS chromatography, and the specific marker components (i.e., oleuropein in olive oil and thymoquinone in black seed oil) were determined by HPLC or sesamin and sesamol were measured by UV spectroscopy in sesame seed oil. Then macerates were prepared with the traditional sun maceration technique. The amounts of the main active components, namely hypericin, hyperforin, and pseudohypericin, were determined by LC-MS and UV methods. Since fixed oils have also known to possess some wound healing activity in vitro and in vivo studies were conducted to determine the wound healing effects of both the fixed oils and the oleates comparatively. The results demonstrated that the wound-healing activity of all oleates were significantly higher comparing to that of the fixed oils used as vehicle. In vivo experiments showed that oleates in olive oil and sesame oil provided the best synergetic effects among the others.