Plant-Derived Therapeutics in Hypertension: A Comprehensive Review of Phytochemical Mechanisms, Clinical Evidence and Translational Perspectives

Despite the many adverse effects of conventional pharmacology, the poor therapeutic response of these drugs and poor adherence to therapy by patients, hypertension still continues to be a major cause of cardiovascular morbidity and mortality worldwide. There is increasing evidence that many plant-derived compounds have potent antihypertensive properties through a variety of mechanisms including ACE inhibition, vasodilation, reduction in oxidative stress, restoration of endothelial function and autonomic nervous system modulation. It is a comprehensive assessment of the phytochemical composition, pharmacological mechanisms, preclinical and clinical investigations and translatability of some of the major medicinal plants with antihypertensive activity. We discuss research on garlic (Allium sativum), hibiscus (Hibiscus sabdariffa), hawthorn (Crataegus species), green tea (Camellia sinensis), olive leaf (Olea europaea), arjuna (Terminalia arjuna), ginseng (Panax ginseng), ashwagandha (Withania somnifera), curcumin (Curcuma longa), and other botanicals with potential cardiovascular benefits. It is important to address the standardization problems, bioavailabilities concerns, drug interaction and regulatory issues that constitute the major impediments to clinical translation. The future possibilities of precision phytomedicine, systems pharmacology and the integration of plant-derived therapeutics into evidence-based cardiovascular treatments are discussed, along with new technology developments based on nanotechnology to deliver phytochemicals. From this study, it can be concluded that plant medicines have great potential as complementary medicines for the treatment of hypertension, but more multicenter clinical trials and chemistry standardisation procedures and mechanistic validation are needed for their general clinical application. Combination of old remedies of the plant kingdom with the newest developments of molecular pharmacology offers plenty of scope for developing novel multi-target antihypertensive agents with improved safety and tolerability.