The effect of hawthorn (Crataegus spp.) on blood pressure: A systematic review

Abstract

Background: Hawthorn (Crataegus spp.) is a herbal medicine used for the treatment of cardiovascular disease, particularly congestive heart failure. Hawthorn is also indicated for the management of hypertension. Objectives: To evaluate the clinical efficacy, dosage forms, and side effects of hawthorn mono-preparations versus placebo for their effects on blood pressure (BP). Methods: Adhering to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we performed a systematic review to identify randomised controlled trials (RCTs) that assessed the effect of hawthorn mono-preparations on BP. The databases AMED (Ebsco), CINAHL, EMBASE (Ovid), and PubMed, and The Cochrane Central Register of Controlled Trials, and grey literature were searched to September 2016. There was no restriction regarding language or date of publication. Data on patients, interventions, methods, outcome measures, results and adverse events were extracted and assessed. The risk of bias (RoB) was assessed using the Cochrane RoB tool. Any queries in study evaluation were resolved through discussion between the authors. Results: The search identified 370 citations. Four trials (254 participants) met the inclusion criteria. Studies administered hawthorn as tablets or liquid drops and reported a reduced BP in patients with pre-hypertension or stage 1 hypertension. No serious adverse side effects were reported. Pooled analysis of the results was not possible because of the heterogeneity of study design, participants and interventions. Significantly reduced BP was shown in three trials of 12- and 16-week duration (P < 0.05). Conclusion: This systematic review found that hawthorn can significantly lower BP in people with mild hypertension if applied for at least 12 weeks. Further trials are suggested to confirm the longer-term, hypotensive effects of hawthorn preparations.