#StreblusAsper

Streblus asper, known locally as Khoi, has long been a steadfast companion in Thai homes and communities. Revered in traditional healing, embedded in folklore, and tied to early Siamese literacy, the tree is more than a plant — it is a cultural symbol. Today, researchers are reexamining Khoi to understand its real potential in modern health while honoring its heritage.

In Isan and other rural regions, Khoi twigs were once chewed as a daily dental care practice. Murals in Ayutthaya even depict children using Khoi bark, illustrating its enduring place in daily life and ritual. The wood’s bitter aroma and distinctive texture have made it a go-to for personal care for generations. But what does current science say about Khoi’s safety and effectiveness?

For centuries, the sturdy branches of ข่อย (Khoi)—scientifically known as Streblus asper—have woven through the everyday lives and healing traditions of Thailand and its Asian neighbors. Revered in traditional medicine, immortalized in local folklore, and even etched into the chronicles of early Siamese literacy, this unassuming “toothbrush tree” continues to captivate the attention of healers and scientists alike. Today, the resurgence of interest in natural health remedies repositions Khoi not just as an artifact of folk heritage, but as a candidate for contemporary herbal medicine, demanding a closer look at the science behind its storied reputation.