Quality and stability assessment of commercial products containing phytoestrogen diaryheptanoids from Curcuma comosa

The Thai traditional medicine “YHA-SA-TREE” or women remedy is composed of many herbs, with phytoestrogenic Curcuma comosa (C. comosa) being the main active ingredient. These C. comosa containing products are popularly used to provide the phytoestrogenic supplements in both pre- and post- menstrual period of women. However, the product quality is not reported. Among several compounds found in C. comosa, diarylheptanoids were reported to possess their phytoestrogenic effects. Therefore, a validated HPLC method was applied to determine the quality of various commercial products containing C. comosa extract and the stability of active compounds under various storage conditions. The analysis of fifteen commercial products containing C. comosa revealed that diarylheptanoid contents varied greatly among products, ranging from 2.61 ± 0.34 to 121.75 ± 1.25% for (4E, 6E)-1, 7-diphenylhepta-4, 6-dien-3-ol (DA1), 4.53 ± 0.24 to 295.00 ± 1.54% for (6E)-1, 7-diphenylhept-6-en-3-ol (DA2), and the diarylheptanoids were not detected in liquid samples. In addition, a stability study of C. comosa extract demonstrated the time-and temperature-dependent degradation of diarylheptanoids with rapid degradation at 40 °C. At 180-day storage, the amounts of DA1 at −20 °C, 4 °C, 25 °C and 40 °C decreased to 91.05 ± 0.27, 82.89 ± 0.20, 83.34 ± 0.54 and 13.33 ± 0.07%, respectively. It was surprising to find that the amount of DA2 also increased to 145.40 ± 0.05% at 40 °C, which suggested that some other compounds in the oleoresin extract of C. comosa could be changed into DA2, and certain degraded products. To ensure the quality and efficacy of products containing C. comosa extract, these products should be stored at low temperature and under low humidity conditions within opaque packaging to prolong shelf life.