Development of a Foot-Care Cream Containing Kaffir Lime Oil for Foot Self-Massage: A Randomized Active-Controlled Trial in Older Adults with Type 2 Diabetes
Year: 2026
Type: article
Abstract: Background/Objectives: Diabetic peripheral neuropathy (DPN) causes foot numbness, pain, and dry skin in older adults with type 2 diabetes (T2D). We developed a Kaffir lime oil foot cream and evaluated its effectiveness and acceptability for self-massage. Methods: Oil composition was analyzed by GC-MS, and anti-inflammatory activity was tested in vitro in LPS-stimulated RAW264.7 macrophages. The cream was tested for stability and microbiological quality. In a randomized active-controlled trial, 92 older adults with T2D and foot numbness were matched and randomized to self-massage with 0.6% Kaffir lime oil cream or 0.5% methyl salicylate cream, twice daily, three days/week, for eight weeks. Primary outcomes were foot numbness and neuropathic pain (DN4, scored per foot and averaged); skin moisture and foot-care behavior were secondary. Outcomes were analyzed with mixed-design ANOVA and ANCOVA. Results: The oil (mainly limonene and β-pinene) reduced nitric oxide production in vitro (IC50 = 224.21 µg/mL). Outcomes improved over time in both groups (all p < 0.01). Numbness showed a group-by-time interaction (p = 0.043), but no between-group difference in numbness was significant at any time point. At week 8, DN4 was slightly lower in the experimental group (adjusted difference −0.43 points on a 0–10 scale; Bonferroni-adjusted p = 0.030), without a significant group-by-time interaction (p = 0.163). No visible skin reactions were observed, and satisfaction among a random subsample of 15 experimental-group participants was high (4.67/5). Conclusions: The cream was acceptable and was associated with slightly lower DN4 scores at week 8; other outcomes did not differ significantly between groups. The numbness and DN4 findings are exploratory and require confirmation in larger, longer, blinded trials in patients with painful DPN. Trial registration: Thai Clinical Trials Registry, TCTR20261007025. Registered retrospectively (first submitted 3 October 2026).
Source: Biomedicines
Institutions: Praboromarajchanok Institute Ministry of Public Health, Srimahasarakham Nursing College, Mae Fah Luang University, Pathumwan Institute of Technology, Prince of Songkla University, Northern College, Udon Thani Rajabhat University, Boromarajonani College of Nursing, Suphanburi, Boromarajonani College of Nursing, Phayao
Language: English
Subfield: Endocrinology, Diabetes and Metabolism
Field: Medicine
Domain: Health Sciences
Open Access status: gold
Estimated APC paid: $3,137
OpenAlex ID: W7225660703