Identification of Potential Skin Sensitizers in Myrrh
TCM and Ethnomedicine Innovation & Development International Laboratory, Innovative Materia Medica Research Institute, School of Pharmacy, Hunan University of Chinese Medicine, Changsha 410208, China
Pharmaceutical Sciences Research center, Health Institute, Kermanshah University of Medical Sciences, Kermanshah 6715847141, Iran
National Center for Natural Products Research, School of Pharmacy, The University of Mississippi, Oxford, MS 38677, USA
Author to whom correspondence should be addressed.
Q.Z. and Y.L. equally contributed to the work.
Cosmetics 2019, 6(3), 47; https://doi.org/10.3390/cosmetics6030047
Received: 4 July 2019 / Revised: 12 July 2019 / Accepted: 17 July 2019 / Published: 1 August 2019
(This article belongs to the Special Issue Cosmetics Contact Allergens)
The exudate of Commiphora myrrha (myrrh) has been known for centuries as one of the most popular natural skin remedies. The characterization and safety assessment of myrrh ingredients are challenging due to the chemical variability of commercially available sources, as well as potential adulteration. Human and animal data have reported potential concerns about myrrh as a skin sensitizer, although no specific chemical entity has been identified as a potential culprit yet. In the present work, the in chemico high-throughput method using dansylated cysteamine (HTS-DCYA) was applied to extract and fractions of myrrh samples in an attempt to identify potential skin sensitizers. Nine oxo-furanogermacranes and the sesquiterpenoid alismol were isolated as major constituents. Five of the compounds were identified as weakly to moderately reactive in HTS-DCYA and could therefore trigger the molecular initiating event leading to skin sensitization. The reactive compounds were identified as 6-oxofuranodienones (2 and 5) and methoxyfuranogermacrenones (7 and 9). The reaction adducts of 2 with DCYA was confirmed by HPLC-DAD-MS and by HPLC-MS/MS experiments. A comparison of the chemical profile of myrrh samples available in-house confirmed a certain degree of chemical variability, with compounds 1, 7, and 9 occurring in four of the six samples.