Review on Phytochemicals and Pharmacological Activities of Syzygium aromaticum

Syzygium aromaticum L (S. aromaticum, clove) is a plant species belonging to the Myrtaceae family. It is cultivated in many African and Asian countries. Folk medicine practitioners use different parts of this plant to treat gastrointestinal problems, diarrhea, dental pain, ulcer, and other chronic diseases. Experimental data on phytochemicals and pharmacological activities of this plant are scattered or unsystematic. Therefore, this review aimed to explore the available data on phytochemicals and pharmacological activities of S. aromaticum essential oil and extracts with various polarities.

The literature review showed that only a few studies were conducted on this plant; consequently, there is not enough documented information about its bioactive phytochemicals and pharmacological activities.

Most previous studies reviewed reported significant bioactive phytochemical contents, namely eugenol (49.7%), caryophyllene (18.9%), benzene, and 1-ethyl-3-nitro (11.1%), along with minor amounts of phytochemicals including carotenoids, gallic acid, flavonoids, oxalic acid, tannins, amino acids, fatty acids, and cyanidin glycoside. Sugars, coumarins, oleanolic acid, saponins, glycosides, and lipids were also identified in this species. The methanol extract of this plant and its different polar fractions were shown to exhibit significant antimicrobial, antioxidant, anti-allergic, antidiabetic, antihypertensive, anti-inflammatory, antifungal, and anticancer activities. Furthermore, the plant extracts were also shown to have chemoprotective and hepatoprotective properties.

This review provides comprehensive data on botanical aspects, phytochemicals, and pharmacological activities of this plant to researchers to explore traditional/ medicinal uses and commercial drug production from S. aromaticum.