The Clinical efficacy and safety of Thai traditional medicine remedy call “Kae Lom Kae Sen” for upper back pain: A Double- Blinded Randomized Controlled Trial.

Abstract

Introduction and Objectives: The prevalence of musculoskeletal disorders has increased in recent years, particularly among the working-age population, primarily due to overuse of muscles and poor posture. This has led to a growing burden on the healthcare system and increased reliance on imported modern medicines. In 2020, Thailand’s importation cost for musculoskeletal drugs reached approximately 7.07 billion baht. Meanwhile, interest in traditional Thai medicine and herbal treatments has been growing. However, the use of herbal remedies remains limited due to the lack of strong scientific evidence. In response, the Ministry of Public Health has promoted the use of herbal medicines by including 97 items in the National List of Essential Herbal Medicines in 2023. In addition, under the medical cannabis policy, several traditional Thai formulations containing cannabis were introduced in public healthcare settings. One such remedy, Kae Lom Kae Sen remedy, comprises seven herbs: white cumin, black cumin, fennel, ginger, plumbago, cannabis leaves, and black pepper. This remedy has been listed in the national herbal drug list and is believed to be effective in muscle pain relief. This study aimed to compare the efficacy and safety of Kae Lom Kae Sen remedy with placebo in relieving upper back muscle pain.

Methods: This study was a double-blind randomized controlled trial conducted among individuals with upper back muscle pain lasting between 2 to 30 days. A total of 60 participants were randomly assigned using computer-generated simple randomization into two groups of 30 each. The intervention group received the Thai herbal formula Kae Lom Kae Sen, composed of seven herbs: Cuminum cyminum, Nigella sativa, Foeniculum vulgare, Zingiber officinale, Plumbago indica, Cannabis sativa leaves, and Piper nigrum, encapsulated in 500 mg capsules. The control group received a placebo identical in appearance. Participants were instructed to take four capsules per day, two capsules in the morning and two in the evening—for seven consecutive days. Efficacy outcomes were assessed using the NRS (numerical rating scale) for pain, the CROM (cervical range of motion) device for neck and shoulder mobility, and an algometer for pressure pain threshold. Follow-up evaluations were conducted on days 3 and 7. Safety was assessed via laboratory investigations, including complete blood count (CBC), renal function tests, and liver function tests. Data were analyzed using descriptive statistics and appropriate inferential tests (Independent t-test, Mann–Whitney U test, Paired t-test, and Wilcoxon Signed Rank Test), with a significance level set at p < 0.05.

Results: All 60 participants completed the study, with > 80% adherence to the intervention. Baseline characteristics such as age, gender, body weight, height, blood pressure, pain duration, and work posture were not significantly different between groups (p > 0.05). Regarding efficacy, the intervention group exhibited a statistically significant reduction in muscle pain scores on days 3 and 7 (from 5.70 to 1.86, p < 0.001), compared to the placebo group (from 5.33 to 4.10, p < 0.001). Cervical and shoulder mobility significantly improved in the herbal group by 8–14 degrees (p < 0.001), while the placebo group showed less consistent improvements. Pressure pain threshold increased in both groups, with greater average improvement in the herbal group, although between-group differences were not statistically significant. Overall treatment assessment revealed that 46.7% of participants in the herbal group reported "very much better," and 6.7% reported "complete recovery," compared to only 3.3% in the placebo group reporting "very much better" and none reporting complete recovery (p < 0.001). Safety outcomes showed no significant differences in CBC, renal, or liver function between groups (p > 0.05), and all values remained within clinical reference ranges. Minor adverse effects such as dry mouth and drowsiness were reported only in the herbal group.

Discussion: The Kae Lom Kae Sen remedy demonstrated greater efficacy than placebo in relieving muscle pain and tendon stiffness, improving range of motion, and enhancing pressure pain tolerance from as early as Day 3 of treatment. These improvements were also consistent with the normative range of cervical and shoulder joint mobility in the general population. Although muscle pain can resolve spontaneously, the findings suggest that this herbal formulation significantly accelerates recovery. Its superior effect may be attributed to the pharmacological properties of its key herbal components, particularly black pepper (Piper nigrum), which contains piperine a compound known for its anti-inflammatory effects through COX-2 enzyme inhibition and suppression of pain-related cytokines and neurotransmitters. Additionally, cannabinoids such as THC and CBD derived from cannabis leaves contribute to reduced pain sensitivity by activating CB1 and CB2 receptors, improving both mobility and pressure pain thresholds. These biomedical mechanisms are in alignment with Thai traditional medicine, which attributes muscle pain to imbalances in the elements, particularly Lom (wind) and Fai (fire). The use of herbs with "hot" properties, such as Kae Lom Kae Sen remedy, helps restore balance by dispersing accumulated wind, alleviating muscle tension, and stimulating blood circulation. Nevertheless, the use of this herbal medicine should be under the supervision of a licensed Thai traditional medicine practitioner or qualified healthcare professional. This is to ensure proper dosage adjustments and to minimize potential adverse effects associated with prolonged use, thereby ensuring patient safety during treatment.

Conclusion and Recommendations: The Kae Lom Kae Sen remedy demonstrated superior efficacy to placebo in relieving upper back muscle pain, improving pain scores, increasing cervical mobility, and enhancing muscle pain pressure tolerance, with a favorable safety profile. Further studies are recommended to explore its active compounds, pharmacodynamics, and long-term safety.