The Effect of St. John's Wort Oil on Urethral Stricture: An Experimental Study in Rat Model.

Objective: The aim was to evaluate the effect of yellow and red centaury St. John's Wort (St. JW) oil on inflammation and urethral fibrosis development in a rat urethral trauma model.

Methods: A total of 24 male rats were divided into 5 groups. No urethral damage was induced in the sham group. The urethras of all rats in the other groups was traumatized at 6 o'clock with a specially designed urethrotome blade. Group 1 was administered 0.5 cc of St. JW oil once daily for 15 days. Group 2 was administered 0.5 cc of red centaury oil intraurethrally once daily for 15 days. The traumatized rats in Group 3 were not treated (St. JW and red centaury oil were not administered). St. JW oil was administered to 3 rats in the Sham 1 group (Group 4), and red centaury oil was administered to 3 rats in the Sham 2 group (Group 5). A 20-G/32-mm intravenous cannula sheath was used for intraurethral administration. On the 15th day, rats were sacrificed and penectomy was performed for histologic evaluation.

Results: Spongiofibrosis, mucosal inflammation, and congestion were significantly decreased in the yellow St. JW oil group when compared with the red centaury oil group and the untreated group (group to which neither St. JW nor red centaury oil was administered).

Conclusion: In this study, intraurethral administration of yellow St. JW oil was found to significantly reduce mucosal inflammation, spongiofibrosis, and obstruction after urethral trauma. According to the results of this study, we think that St. JW oil may be a promising option in the treatment of urethral stricture.