Traditional herbal therapies for hypertension: A systematic review of global ethnobotanical field studies

The worldwide burden of hypertension and its associated cardiovascular diseases have urged researchers to explore for alternative therapies. Together with laboratory studies, field surveys on the documentation of traditional antihypertensive therapies have expanded across the world. However, a compilation and analysis of these field studies has not been done so far. This review aim to document all traditional medicinal plants used globally for the management of hypertension. Field studies were retrieved from main databases including Sciencedirect, Medline/PubMed, and Google Scholar. 433 surveys were obtained which dated from 1970 to 2019. A total of 1329 traditionally used plant species (823 genera and 176 families) were reported across 90 countries against hypertension. Compositae (Genera: 68; Species:103) and Lamiaceae (Genera:39; Species:103) were the families with the most used species. The main species (in order of number of reports) were Allium sativum L., followed by Olea europaea L., Allium cepa L., Annona muricata L., Persea americana Mill., Citrus aurantiifolia (Christm.) Swingle, Catharanthus roseus (L.) G.Don, Moringa oleifera Lam., Cymbopogon citratus (DC.) Stapf, and Carica papaya L. Pakistan (Family:81; Species:246) reported the highest number of plant species followed by Mexico, Nigeria, India, Algeria, Morocco, Thailand, Suriname, Benin, and Iran. Leaf (35%), fruit (12%), and root (10%) were the most preferred plant parts while the main methods of preparation were decoction (50%) and infusion (22%). This study is the first of its kind to compile all traditionally used hypotensive medicinal plants across the world. It is recommended that another systematic review be conducted on the biological properties of all identified species in our review to identify those which have been scientifically validated in in vitro, in vivo, and clinical studies before they can be considered as alternative or complementary antihypertensive therapies. (c) 2020 SAAB. Published by Elsevier B.V. All rights reserved.