Juergens U R, Stöber M, Vetter H
Abteilung Pneumologie, Medizinische Universitäts-Poliklinik, Wilhelmstrasse 35-37, D-53111 Bonn, Germany.
Eur J Med Res. 1998 Dec 16;3(12):539-45.
The anti-inflammatory efficacy of monoterpenes is still unknown. In order to evaluate the potential role of L-menthol and mint oil as an anti-inflammatory drug, preclinical in vitro-investigations were performed using LPS-stimulated monocytes from healthy volunteers. Arachidonic acid metabolism was assessed by measuring LTB subset4 and PGE subset2 as indicators for both the lipoxygenase and the cyclooxygenase pathways respectively. In addition, the anti-inflammatory effects of the two terpenes on IL-1beta production were analysed. - L-menthol significantly suppressed the production of each of the three inflammation mediators by monocytes in vitro. LTB subset4 decreased by -64.4 +/- 10%, PGE subset2 by -56.6 +/- 8%, and IL-1beta by -64.2 +/- 7% respectively at L-menthol concentrations within the presumed therapeutic range of about 10 superset-7 g/ml. In contrast, mint oil had a bimodal effect on PGE subset2 production: lower concentrations of 10 superset-10 to 10 superset-8 g/ml increased PGE subset2 up to 6-fold compared to baseline but concentrations of 10 superset-7 g/ml suppressed PGE subset2 production by approximately 50%. Mint oil had similar effects on LTB subset4 and IL-1beta as its main constituent, L-menthol, although the degree of suppression was by comparison smaller at lower concentrations. Paraffin oil, which served as a solvent, did not affect arachidonic acid metabolism and IL-1beta production. - These results obtained with human monocytes suggest preferable anti-inflammatory effects of L-menthol compared to mint oil at therapeutically relevant concentrations supplied in enteric coated capsules. Therefore, clinical trials investigating the potential therapeutic efficacy of L-menthol for treatment of chronic inflammatory disorders such as bronchial asthma, colitis and allergic rhinitis seem worthwhile.
单萜类化合物的抗炎功效尚不清楚。为了评估L-薄荷醇和薄荷油作为抗炎药物的潜在作用，使用来自健康志愿者的脂多糖刺激的单核细胞进行了临床前体外研究。通过分别测量白三烯B4（LTB4）和前列腺素E2（PGE2）作为脂氧合酶和环氧化酶途径的指标来评估花生四烯酸代谢。此外，分析了这两种萜类化合物对白细胞介素-1β（IL-1β）产生的抗炎作用。-L-薄荷醇在体外显著抑制单核细胞产生三种炎症介质中的每一种。在假定的治疗范围约10⁻⁷g/ml的L-薄荷醇浓度下，LTB4分别降低了-64.4±10%，PGE2降低了-56.6±8%，IL-1β降低了-64.2±7%。相比之下，薄荷油对PGE2的产生有双峰效应：与基线相比，10⁻¹⁰至10⁻⁸g/ml的较低浓度使PGE2增加高达6倍，但10⁻⁷g/ml的浓度使PGE2产生抑制约50%。薄荷油对LTB4和IL-1β的作用与其主要成分L-薄荷醇相似，尽管在较低浓度下抑制程度较小。用作溶剂的石蜡油不影响花生四烯酸代谢和IL-1β的产生。-这些用人单核细胞获得的结果表明，在肠溶胶囊提供的治疗相关浓度下，L-薄荷醇比薄荷油具有更好的抗炎作用。因此，研究L-薄荷醇治疗慢性炎症性疾病如支气管哮喘、结肠炎和过敏性鼻炎的潜在治疗效果的临床试验似乎是值得的。
