Antioxidant activity of medicinal plants and herbs of North Aegean, Greece: Current clinical evidence and future perspectives

Abstract

Medicinal plants and herbs constitute rich sources of flavoring, and aromatic compounds, namely phytochemicals, which have many positive impacts on human health, such as antioxidant, anticancer, antimicrobial, anti-inflammatory, cardioprotective, and neuroprotective properties. Such bioactive compounds may be considered lead compounds that can be introduced in the drug design process to obtain novel drug candidates with better bioavailability and therapeutic efficiency. The Islands of the North Aegean have rich biodiversity and many medicinal plants and herbs with multiple health benefits. This study aims to summarize and scrutinize the antioxidant activity of medicinal plants and herbs of the North Aegean islands. A thorough search of the existing literature was performed in the most accurate scientific databases, using a set of effective and relative keywords and including only clinical human studies written in English. Several clinical studies have highlighted the potential antioxidant activity of phytochemicals from plants such as St. John's wort, chamomile, rosemary, spearmint, mastiha, mountain tea, oregano, sage, and thyme, as measured in the blood and saliva of human individuals, after administration of extracts and solutions of these plants. Decreased levels of oxidized lipoproteins, increased activity of antioxidant enzymes, and an enhanced total antioxidant capacity were observed. Current clinical trials remain still limited, and an enhanced series is needed with a better methodology design, larger sample size, longer intervention periods, using controlled groups and randomization to unravel the antioxidant activity of these North Aegean endemic plants in human individuals.