Ocimum gratissimum: Chemical Composition, Phytochemical Properties, Antioxidants, and Pharmacological Activities: A Review

Ocimum gratissimum L. subsp., commonly known as African basil, is a native African medicinal plant that has been used for generations to address various health issues. These include colds, flu, diabetes, diarrhoea, pain and swelling, psychological disorders, malaria, inflammation, and infections caused by fungi and bacteria. In addition, African basil is abundant in vitamins and minerals and is mostly used to add flavour to dishes and soups in West African households. Studies have identified multiple bioactive compounds in this plant, such as alkaloids, polyphenols, triterpenes, steroids, fatty acids, esters, alcohols, essential oils, ketones, and aldehydes. Key bioactive constituents, essential oils like thymol and eugenol, are responsible for the pharmacological effects of Ocimum gratissimum. The diverse bioactive compounds give the plant a wide range of therapeutic properties, including antioxidant, cognitive-enhancing, antimicrobial, anti-inflammatory, analgesic, anticancer, antihypertensive, hepatoprotective, and organoleptic effects. Notable mechanisms of action include the PI3K/Akt, NRF-2, and NF-κB signalling pathways, free radical scavenging, and modulation of pro-inflammatory cytokines such as IL-1β, IL-6, and TNF-α. This review paper aimed to compile recent studies on the phytochemistry, medicinal uses, therapeutic activities, and molecular mechanisms of action of Ocimum gratissimum. Further studies are needed to better understand the effects of Ocimum gratissimum at the pathological and molecular levels.