Evaluation of Allergenicity of Constituents of Myoga Using the Murine Local Lymph Node Assay

Abstract

Myoga (Zingiber Myoga Roscoe) is a perennial plant with a pungent smell from its flower buds. It is native to East Asia and has been reported to cause allergic contact dermatitis. The purpose of this study is to assess the allergenicity of myoga related to its major chemical components, «-pinene, p-pinene, limonene, llmonene oxide and p-phellandrene, which are supposed to be the causative agents of contact dermatitis among myoga cultivators. We performed a toxicity study of the volatile constituents of myoga using the local lymph node assay (LLNA), in which llmonene, limonene oxide and p-phellandrene had positive responses and the EC3 was 35.8%, 8.22%, and 0.54%, respectively. EC3 for both «-pinene and p-pinene was over 100%. Both chemicals failed to induce positive responses in the LLNA. While the maximization rating of limonene, llmonene oxide and phellandrene were evaluated as moderate, extreme, and extreme respectively, u-plnene and p-pinene were evaluated as weak in the previously reported GPMT. The usage ofLLNA was also confirmed by comparing with previously reported GPMT results to detect the allergenicity of myoga constituents. The actual risk of humans developing an allergy to myoga constituents depends on many factors. The concentration ofthe compounds, the frequency and duration of exposure and the condition of the skin are supposed to be important factors. Myoga (Zingiber Myoga Roscoe) is a perennial plant with a pungent smell of its flower buds and is of East Asian origin (1), belonging to the ginger family (Zingiberacea). The Japanese have long eaten the flower buds as a spice or pickle. The technology for cultivating myoga in greenhouses was established in the 1990s, enabling the flower buds to be supplied to markets all year round. Myoga greenhouses have increased in some areas in Japan, while hand dermatitis suspected to be due to the allergenicity to myoga has been recognized among myoga greenhouse cultivators.Minamoto et al. first reported a case study of contact dermatitis from myoga (2-3), before which contact dermatitis from myoga was unknown (4). According to our earlier investigation of myoga cultivators in Japan, 8 of 35 cultivators experienced contact dermatitis during the harvest season (2-3).

Assessment of the different skin sensitization potentials of irritants and allergens as single substances and in combination using the KeratinoSens assay

“… b Sensitization class according to LLNA; for SDS classification human data were taken 13 ; for α‐pinene different results were reported 23,24 . …”

“…Patch tests revealed allergic reactions and α‐pinene was confirmed as a weak allergen in the guinea pig maximization test. However, it failed to induce a positive response in the LLNA 23,24,40 . Besides, pinenes do not have the structural properties to bind covalently to skin proteins 39 .…”

Therapeutic Potential of Volatile Terpenes and Terpenoids from Forests for Inflammatory Diseases

“…According to the Food and Drug Administration, camphor-containing products cannot exceed 11% camphor. In addition, allergic contact dermatitis has been reported following the use of α-pinene, β-pinene, and myrcene [175,177,178,190]. This issue draws attention on the need to further explore the safe concentrations of terpenes for therapeutic proposes [191].…”

“…However, in addition to the beneficial effects of the above volatile terpene compounds on AD, many adverse cases have also been reported. In evaluation studies using various assays, many compounds including α-pinene, β-pinene, limonene, beta-phellandrene, and camphor, have been reported to show positive allergenicity responses causing contact dermatitis [175][176][177]. Despite their beneficial activities as antioxidants, some volatile terpene compounds can autoxidize rapidly to skin allergens on air exposure.…”

Cholesterol: An Inflammatory Compound

“…Soluble YCAM-I, for example, does not predict the risk of future myocardial infarction in apparently healthy men (41)(42)(43)(44). However, research has repeatedly and unequivocally demonstrated the essential role of YCAM-I in experimental atherosclerotic lesion initiation and progression (45)(46)(47)(48)(49) .…”