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?
Khoi grows across Southeast Asia, thriving in drier climates found in Thailand, Cambodia, and neighboring areas. Locally, it carries several regional names that reflect dialectical and cultural nuances. Traditional pharmacopeias in Thailand and nearby regions describe Khoi for a range of uses — from toothache and fever to skin ailments, and historically for more serious conditions. Modern observers note that every part of the plant — roots, bark, leaves, and latex — has figured in old medical cabinets.
Beyond medicine, Khoi is a cultural touchstone. Before modern paper, Thai communities crafted durable bark sheets from Khoi to preserve manuscripts for generations. The tree’s link to literacy, ritual, and care endures as part of Thailand’s living heritage.
What does contemporary science say about Khoi’s alleged healing powers? Recent lab-based and animal studies show promising yet preliminary results. Khoi contains bioactive compounds, including cardiac glycosides, tannins, flavonoids, and saponins, which underpin several pharmacological activities that echo traditional uses. For example, antiviral and anti-inflammatory properties have attracted attention from researchers exploring plant-derived therapies in a world confronting resistant pathogens.
A 2024 study reported ten new cardiac glycosides from Khoi roots, highlighting potential antiviral activity. Other experiments found that ethanolic extracts from Khoi leaves reduced inflammation in rat models, offering a pharmacological explanation for traditional uses against gum swelling and pain. Additional work suggests activity against oral pathogens, aligning with Khoi’s longstanding reputation as a natural dental aid.
Khoi remains a topic of interest in dental health research. Some Thai communities still use Khoi twigs for oral care, and early laboratory comparisons with commercial mouthwashes show reductions in plaque and bacterial growth. Rural health volunteers in central Thai regions have long observed improved dental resilience through Khoi chewing, reinforcing the cultural familiarity with this practice.
Beyond the mouth, Khoi exhibits a broader pharmacological profile. Laboratory studies point to antioxidant and antidiabetic activities, with extracts from bark and leaves showing potential in lowering blood sugar and mitigating oxidative stress. Research from India and Southeast Asia also documents anti-diarrheal and wound-healing properties, reflecting traditional use for digestive and skin conditions.
Some studies emphasize caution. While certain cardiac glycosides can contribute to therapeutic effects, they can also pose toxicity risks if misused or taken in excess. Researchers stress that human clinical evidence remains limited, and robust trials are needed to confirm safety and efficacy for major health conditions. As with many traditional remedies, personalized assessment and professional guidance are advised, especially for children, pregnant individuals, and those with heart conditions.
Thailand’s public health authorities regulate traditional remedies to balance respect for heritage with patient safety. This stance echoes older Thai medical practice, which emphasized individualized treatment and professional oversight. Before incorporating Khoi into any health routine, consult qualified medical or traditional health professionals and seek products that are standardized and responsibly sourced.
The future of Khoi hinges on a careful blend of respect for tradition and rigorous science. As interest in sustainable, locally sourced remedies grows, Streblus asper offers potential in antiviral, anticancer, and oral health applications, while underscoring the need to protect native Khoi stands as a valuable genetic and cultural resource.
For Thai readers seeking practical guidance, consider products that come from reputable programs supported by public-health initiatives or traditional-medicine clinics affiliated with public hospitals. Always prioritize safety, traceability, and professional advice when exploring Khoi for health purposes.
In sum, Streblus asper embodies a living Thai heritage — a bridge between ancestral knowledge and evidence-based medicine. By marrying tradition with science, Khoi may continue to inspire safe, culturally integrated health solutions for families across Thailand.