Study of anti-inflammatory activities of α-D-glucosylated eugenol.

Inflammation is an immune response against a variety of noxious stimuli, such as infection, chemicals, and physical injury. Eugenol, a natural phenolic extract, has drawn much attention for its various desirable pharmacological functions and is, therefore, broadly used in our daily life and medical practice. However, further usage of eugenol is greatly limited due to its unwanted properties, such as physicochemical instability, poor solubility, and high-dose cytotoxicity. In hopes of extending its applicability through glycosylation, we previously reported a novel, efficient, and high throughput way to biosynthesize α-D-glucosylated eugenol (α-EG). In this study, we further explored the potential superior properties of α-EG to its parent eugenol in terms of anti-inflammatory activities. We demonstrated that α-EG was an effective anti-inflammatory mediator in both non-cellular and cellular environments. In addition, the non-cellular inhibitory effect of α-EG could be amplified by α-glucosidase, which ubiquitously exists in cytoplasm. Furthermore, α-EG exhibited a superior anti-inflammatory effect to its parent eugenol in a cellular environment. In words, our findings collectively suggest that α-EG is a stronger anti-inflammatory mediator and may thereby serve as a desirable substitute for eugenol and a potential therapeutic prodrug in treating inflammatory diseases in the future.