The effect of St. John's wort (Hypericum perforatum) on wound healing of oral mucosa in diabetic rats

The purpose of this study is to investigate the histopathological and biochemical effects of the topical application of Hypericum perforatum (Centaury) on wound healing in the oral mucosa of experimentally induced diabetic rats. In the study, 48 5-months-old male Wistar Albino rats were used. The animals for the experiment were was divided into two main groups as control and study group, each consisting of 24 rats. The main groups were divided into three subgroups according to the days when the animals would be sacrificed. All rats were given streptozotocin in 60 mg/kg dosage and after 72 hours, the ones with measured blood glucose levels above 200 mg/dl were included in the study. Mucosal defects were created in the palatal area of rats. Centaury oil was applied topically twice a day to the wounds of rats in the study group. No applications to the wounds were made in the control group. In all groups sacrificed, samples were taken from the palate wounds created on the 3rd, 7th and 10th days. Histopathological and biochemical analyses were performed on the samples taken. As the result of statistical analysis performed, no significant difference between 3rd day groups was observed (p>0.05). On the 7th day, ulceration, necrosis, epithelialization, PNL and hydroxyproline parameters showed statistically significant differences (p<0.05). It was found that ulceration, necrosis and PNL values of these parameters were higher in the control group; whereas the epithelialization and hydroxyproline values were found to be higher in the centaury administered group. Among 10th day groups, there was only a statistically significant difference between the values of hydroxyproline, whereas the centaury treated group showed high hydroxyproline levels (p<0.05). This study indicated that, topically applied Hypericum perforatum does not create any difference for experimentally induced diabetic rats on the 3rd day, while the wound healing rate accelerated on 7th and 10th days. Key words: Diabetes mellitus, Hypericum perforatum, St. John's Wort, Wound healing