Syzygium aromaticum L. (Myrtaceae): Traditional Uses, Bioactive Chemical Constituents, Pharmacological and Toxicological Activities

Herbal medicinal products have been documented as a significant source for discovering new
pharmaceutical molecules that have been used to treat serious diseases. Many plant species have been
reported to have pharmacological activities attributable to their phytoconstituents such are glycosides,
saponins, flavonoids, steroids, tannins, alkaloids, terpenes, etc. Syzygium aromaticum (clove) is
a traditional spice that has been used for food preservation and possesses various pharmacological
activities. S. aromaticum is rich in many phytochemicals as follows: sesquiterpenes, monoterpenes,
hydrocarbon, and phenolic compounds. Eugenyl acetate, eugenol, and -caryophyllene are the most
significant phytochemicals in clove oil. Pharmacologically, S. aromaticum has been examined
toward various pathogenic parasites and microorganisms, including pathogenic bacteria, Plasmodium,
Babesia, Theileria parasites, Herpes simplex, and hepatitis C viruses. Several reports documented
the analgesic, antioxidant, anticancer, antiseptic, anti-depressant, antispasmodic, anti-inflammatory,
antiviral, antifungal, and antibacterial activity of eugenol against several pathogenic bacteria
including methicillin-resistant Staphylococcus epidermidis and S. aureus. Moreover, eugenol was
found to protect against CCl4􀀀induced hepatotoxicity and showed a potential lethal ecacy against
the multiplication of various parasites including Giardia lamblia, Fasciola gigantica, Haemonchus contortus,
and Schistosoma mansoni. This review examines the phytochemical composition and biological activities
of clove extracts along with clove essential oil and the main active compound, eugenol, and implicates
new findings from gas chromatography-mass spectroscopy (GC-MS) analysis.