Programa de Pós Graduação em Microbiologia e Parasitologia, Laboratório de Micologia, Departamento de Microbiologia e Parasitologia, Instituto de Biologia, Universidade Federal de Pelotas, Prédio 18, Sala 14. Campus Universitário Capão do Leão, s/n◦, Pelotas, RS, CEP: 96160-000, Brazil.
Centro de Ciências da Saúde, Universidade Federal de Santa Maria, Santa Maria, RS, Brazil.
Braz J Microbiol. 2022 Jun;53(2):1011-1017. doi: 10.1007/s42770-022-00720-6. Epub 2022 Mar 3.
Essential oils (EO) are aromatic compounds from the plant secondary metabolism. Melaleuca alternifolia EO is well known for its medicinal properties and promising use as an antimicrobial agent. Pythiosis is a difficult-to-treat and emerging disease caused by the oomycete Pythium insidiosum. This study evaluated a nanoemulsion formulation of M. alternifolia (NEMA) in topical and intralesional application to treat experimental pythiosis. Dermal toxicity tests were performed on M. alternifolia EO in Wistar rats. Pythiosis was reproduced in rabbits (n = 9) that were divided into groups: group 1 (control), cutaneous lesions with daily topical application of a non-ionizable gel-based formulation and intralesional application of sterile distilled water every 48 h; group 2 (topical formulation), lesions treated daily with topical application of a non-ionizable gel-based formulation containing 5 mg/ml of NEMA; and group 3 (intralesional formulation), lesions treated with NEMA at 5 mg/ml in aqueous solution applied intralesionally/48 h. The animals were treated for 45 days, and the subcutaneous lesion areas were measured every 5 days. M. alternifolia EO showed no dermal toxicity. The lesion areas treated with intralesional NEMA reduced at the end of treatment, differing from groups 1 and 2 (P < 0.05). In the topically treated group, the lesion areas did not differ from the control group, although the number of hyphae significantly reduced (P < 0.05). Under the experimental conditions of this study, the NEMA formulations presented a favorable safety profile. However, further studies are required to evaluate if this safety applies to higher concentrations of NEMA and to validate its use in clinical pythiosis.
精油（EO）是植物次生代谢产生的芳香化合物。互叶白千层精油以其药用特性和作为抗菌剂的应用前景而闻名。瓶霉病是一种由卵菌纲瓶霉属引起的难以治疗和新兴疾病。本研究评估了互叶白千层纳米乳剂（NEMA）在局部和病灶内应用治疗实验性瓶霉病的效果。在 Wistar 大鼠身上进行了互叶白千层精油的皮肤毒性试验。在兔子（n = 9）身上复制了瓶霉病，将其分为三组：第 1 组（对照组），皮肤病变，每天用非离子凝胶制剂局部应用，并每 48 小时病灶内应用无菌蒸馏水；第 2 组（局部制剂），每日用含有 5mg/ml NEMA 的非离子凝胶制剂局部治疗；第 3 组（病灶内制剂），用 5mg/ml 的 NEMA 水溶液病灶内注射/48h 治疗。动物治疗 45 天，每 5 天测量一次皮下病变面积。互叶白千层精油无皮肤毒性。病灶内 NEMA 治疗组在治疗结束时病变面积减小，与第 1 组和第 2 组不同（P < 0.05）。局部治疗组，虽然真菌数量显著减少（P < 0.05），但病变面积与对照组无差异。在本研究的实验条件下，NEMA 制剂具有良好的安全性。然而，还需要进一步的研究来评估更高浓度的 NEMA 是否具有这种安全性，并验证其在临床瓶霉病中的应用。
