Objective: The aim of this study was to determine the effects of Hypericum perforatum on cesarean wound healing and hypertrophic scar. Design: This was a randomized, double-blind clinical trial study. Setting: The study was conducted in Samen-Ol-Aemmeh (Pbuh) Hospital in Mashhad, Iran. Subjects: The subjects included 144 women with surgical childbirth who had eligible criteria. Intervention: The participants were randomly assigned to three groups. The treatment and placebo groups applied H. perforatum or placebo ointment 3 times a day for 16 days based on consecutive coded ointments. The control group remained without any intervention postoperatively. Assessment: Wound healing was assessed on the 10th day postcesarean using the REEDA scale (REEDA stands for redness, edema, ecchymosis, discharge, and approximation), which had criteria including redness, edema, ecchymosis, discharge, and approximation. On the 40th day, the degree of scarring was assessed using the Vancouver scar scale including pigmentation, height, pliability, and vascularity. The subjects were also asked some questions about pain by using the Visual Analogue Scale and pruritus of scar. Results: The mean age of all the study subjects was 23.50 ± 4.03 and mean parity was 1.23 ± 0.48. There were significant differences in wound healing on the 10th day (p < 0.005) and scar formation on the 40th day postpartum (p < 0.0001) between treatment group with placebo and control groups. However, the placebo group had no differences in wound healing (p = 0.93) and scar formation (p = 0.11) with the control group. In addition, significantly lower pain and pruritus were reported by the treatment group compared with the placebo and control groups on the 40th day postpartum. Conclusions: Topical application of H. perforatum is safe and can facilitate cesarean wound healing and minimize formation of scar and its pain and pruritus.

Hypericum perforatum (Hypericaceae), known as Saint John's wort (SJW), has been used in different systems of traditional medicine such as Chinese traditional medicine, Greek traditional medicine, and Islamic traditional medicine. The plant and its active constituents such as hyperforin and hypericin have a wide range of medicinal uses, particularly as anti-depressant, wound-healing, and antibacterial agents. In recent decades, many clinical trials have been performed to investigate the safety and efficacy of this medicinal plant. However, to the best on our knowledge, there is no comprehensive review article in this regard. In the current study, we aim to have a comprehensive review of the clinical trials of SJW to evaluate its efficacy and safety as well as its application in traditional medicine. Clinical studies investigating the safety, interactions, and efficacy of SJW were identified and summarized, including contributions from 2000 until December 2021. According to the results, these clinical studies were divided into three main categories based on the type of disease: psychiatric, endocrine, and skin problems. Important details of the studies, including the type and duration of the study, the type and percentage of the effective compounds or the extract used, the number of patients, and the obtained results were also discussed. In addition, co-administration and drug interaction of SJW with other drugs were summarized. SJW is a valuable medicinal plant, especially for psychiatric disorders. However, precautions should be taken while administrating the plant.