Clinical antihypertensive efficacy and safety of Iran plants: a systematic review

Background: Antihypertensive plants are one of the means of hypertension control. Objective: To examine the clinical antihypertensive efficacy and safety of the plants found in Iran. Methods: PUBMED, MEDLINE, SCOPUS, EMBASE, SCIENCEDIRECT, PROQUEST, OVID, EBSCO, GOOGLE, and GOOGLE SCHOLAR were searched. The PRISMA guideline was observed. The search terms were Iran, Iranian, plant, herb, antihypertensive, hypertension and randomized controlled trial (RCT). English-language articles published until the end of 2022 were included. In-vitro and animal studies, editorials, and reviews were excluded. The methodological quality of the RCTs was evaluated using the JADAD scale. Results: Two hundred and eight studies were found. Only 74 of them were eligible. For Berberis vulgaris (5 studies), Nigella sativa (10 studies), Allium sativum (12 studies), Hibiscus sabdariffa (11 studies), Beta vulgaris L (15 studies), Solanum lycopersicum (5 studies), Cinnamomum verum (9 studies), Rhus coriaria (1 study), Phyllanthus emblica (1 study), Olea europaea (4 studies), and Vaccinium arctostaphylos (3 studies) were found. Most RCTs had high methodological quality and reported efficacy and no side effects. Conclusion: While most trials demonstrate antihypertensive efficacy and safety, there are more evidence regarding Hibiscus sabdariffa, Olea europaea, Vaccinium arctostaphylos and Allium sativum versus the other plants.