Juniperus oxycedrus L. fruit, leaves, and essential oil: a systematic literature review on bioactive compounds, pharmacological properties and toxicology

Prickly juniper (Juniperus oxycedrus; Cupressaceae family), is a wild plant that grows spontaneously in the Mediterranean and Near East regions. This manuscript provides an updated overview of J. oxycedrus fruit, leaves, and essential oil (EO) chemistry, as well as their biological activities and toxicity, through a systematic search in the most known scientific databases: Scopus, Web of Science, and PubMed. After application of the inclusion/exclusion criteria, 70 studies were included. The findings indicate that phenolic acids (protocatechuic, p-coumaric, chlorogenic and p-hydroxybenzoic acids), flavonoids (hesperidin, quercetin 3-O-rutinoside, naringenin, amentoflavone, cupressuflavone and apigenin) and their derivatives, besides lignans (matairesinol and secoisolariciresinol), coumarins (7-hydroxycoumarin and aesculetin), and the organic compound shikimic acid are the main bioactive molecules isolated from the fruit and leaves of J. oxycedrus. On the other hand, the EOs extracted from these plant parts could be considered rich sources of many volatile molecules, including α- and β-pinene, limonene, β-myrcene, D-germacrene, p-cymene, and sabenine. So far, numerous animal, cell-based and in vitro studies have investigated the pharmacological activities of J. oxycedrus. Among the reported bioactivities, we found anti-inflammatory, anti-diabetic, antibacterial, antifungal, antiviral, cytotoxic and anti-proliferative, cholinesterase enzyme inhibitory, wound healing and antioxidant activities. However, novel extraction methods should be used, and in-depth studies are encouraged to confirm the reported bioactivities, isolate the active constituents, and evaluate the toxicity of J. oxycedrus fruit and leaves extracts, fractions and EOs. This is crucial for any future clinical trials or phytotherapeutics development.