Koh Khlan, known across Thailand by several local names such as makay kreua and yeo maeo, has long been a source of traditional healing. In rural communities from the northern hills to Isan, families rely on its bark, leaves, and stems to ease muscle, bone, and joint pains. Scientifically, the plant is Mallotus repandus, a member of the Euphorbiaceae family, widely used in Thai herbal blends that aim to restore vitality in daily life.
In an era of rising pharmaceutical use, Koh Khlan’s enduring popularity underscores the value of cultural memory and plant-based knowledge in Thai society. Elders in villages continue to pass down preparation methods, while researchers work to clarify how traditional practice and modern science may align—and where they may diverge.
The plant’s significance in Thai remedies lies in both its chemistry and its stories within rural life. Practitioners in Northeast Thailand often incorporate its wood or bark into decoctions targeting bone pain, chronic stiffness, and injuries from hard labor. Its reputation as a pain reliever is strong enough to anchor a well-known formula on Thailand’s National List of Essential Medicines, highlighting its place in the country’s health system. In central and northeastern provinces, Koh Khlan is also used as an herbal antibiotic and for wound healing, reflecting a biodiversity-driven tradition built over generations.
This practice mirrors a Thai belief in balance—within the body and with the surrounding environment. Multi-herb remedies emphasize a holistic approach that seeks to restore equilibrium, not merely suppress symptoms, by cooling inflammation and easing chronic soreness.
As interest in evidence-based medicine grows, researchers are exploring what, if anything, validates Koh Khlan’s traditional claims.
A 2014 study in BioMed Research International examined methanolic extracts of Mallotus repandus leaves in animal models. The findings showed significant pain-relieving and anti-inflammatory effects, with responses increasing at higher doses. The extract appeared to act through both central and peripheral mechanisms, supporting traditional claims that Koh Khlan affects both surface and deeper sources of pain.
Phytochemical analyses reveal a rich mix of compounds in Mallotus repandus, including flavonoids, tannins, and saponins, known for antioxidant and anti-inflammatory properties. Laboratory work indicates the plant extract can reduce inflammatory mediators such as TNF-α and IL-1β while boosting anti-inflammatory IL-10, suggesting immunomodulatory activity. This supports the idea that Koh Khlan’s power stems from the synergy of its constituents, a hallmark of traditional multi-herb formulas.
Further studies identify bergenin as a major anti-inflammatory component, though the whole extract tends to be more effective than bergenin alone, underscoring the importance of the plant’s composite chemistry.
Recent investigations also highlight antioxidant activity, with the stem’s ethyl acetate fraction showing notable scavenging of superoxide radicals. This aligns with traditional uses in wound healing and cooling effects and points to potential broader applications in conditions driven by inflammation and oxidative stress.
Outside Thailand, the plant’s use appears in other countries. In Bangladesh, Mallotus repandus is used to counteract snakebites and itching, while in Taiwan it features in anti-inflammatory therapies. This cross-cultural resonance reflects global interest in integrating indigenous knowledge with modern medicine.
Despite promising findings, caution is essential. Toxicity studies of methanolic extracts in animal models have not shown kidney, liver, or blood toxicity even at high doses. However, long-term safety in humans remains under-documented. Use should be supervised by qualified practitioners, particularly for individuals with preexisting conditions, pregnant women, or those on prescription medications. While rare, potential allergic reactions or interactions warrant careful guidance.
The story of Koh Khlan intertwines ecological and social dimensions. Herbal medicine embodies a living heritage in Thailand—guarded by community forest networks and local healers, and documented through academic and governmental efforts to conserve and standardize traditional knowledge. Seasonal forest walks in Isan, where elders guide youths to identify and harvest healing plants, illustrate how Koh Khlan symbolizes continuity, adaptability, and hope within rural life and health policy.
Looking ahead, Koh Khlan could inform integrative medicine by contributing to biomedical approaches to musculoskeletal pain and inflammation. Realizing its potential requires human clinical trials focusing on efficacy, standardization, and long-term safety. Conserving the plant’s habitat and promoting sustainable harvesting remain essential to preserve both environmental health and cultural relevance.
Practical guidance for Thai readers:
- Respect time-honored remedies like Koh Khlan while aligning traditional knowledge with current scientific insights.
- Use herbal medicines under the supervision of qualified professionals, with proper diagnosis and monitoring.
- Stay informed about new findings from Thai universities and international journals, as well as local practitioners.
- Support efforts to protect Thailand’s medicinal plant diversity and the cultural knowledge behind it.
In sum, Koh Khlan’s journey from village forests to scientific journals reflects Thailand’s capacity to blend old wisdom with contemporary possibilities.
This article is educational. Seek advice from a qualified healthcare provider before considering any herbal or traditional remedy, especially with pre-existing conditions or when taking prescribed medications. Efficacy and safety vary with preparation, dosage, and individual health.