Croton tonkinensis Gagnep., commonly named in Vietnamese as "Kho sam Bac Bo", is a tropical shrub native to the Northern Vietnam. Its dried leaves (Folium Tonkinensis) have been used in Vietnamese traditional medicine to treat boils, abscesses, impetigo, abdominal pain, dyspepsia, dysentery, gastric and duodenal ulcers [1, 2]. The plant is of our interest since its varied biological activities demonstrated in our various in vitro bioassays including anti-inflammatory, anticancer, antiplasmodial, antibacterial and antifungal.