Thunbergia laurifolia Linn. has also been recommended by Thai traditional healers for treating diabetes. It is a climbing plant with smooth opposed leaves along the stem. The leaves are 8-10 cm long and 4-5 cm broad, broad-based, narrowing to a pointed tip, usually with scalloped lobes towards the base. The purple flowers are trumpet-shaped and produced during November-January. The seed pod is cone-shaped, 1 cm long, with a round base. In Thailand, it is called Rang Juad, Yaw Kaew, Kob Sha Nang, Gum Lung Chang Puak, or Krua Nan Nae in the North. Generally, this plant could be used for various purposes, including anti-toxicity, antiinflammatory, and in the treatment of pneumonia (Utogapachn, 1976). According to Thai traditional medicine, a mixture of the root or leaf of T. laurifolia with water rinsed from rice can be effectively used as a detoxifying agent. The antidotal activity of T. laurifolia against insecticides has been confirmed by scientific research (Tejasen and Thongthapp, 1980). Nevertheless, reports of its anti-diabetic activity are still insufficient.