Waller Stefanie Bressan, Hoffmann Jéssica Fernanda, Madrid Isabel Martins, Picoli Tony, Cleff Marlete Brum, Chaves Fabio Clasen, Zanette Régis A, de Mello João Roberto Braga, de Faria Renata Osório, Meireles Mário Carlos Araújo
Department of Preventive Veterinary, Federal University of Pelotas, Pelotas, RS, Brazil.
Department of Agroindustrial Science and Technology, Federal University of Pelotas, Pelotas, RS, Brazil.
Med Mycol. 2018 Feb 1;56(2):225-233. doi: 10.1093/mmy/myx031.
Oregano (Origanum vulgare) has anti-Sporothrix spp. activity, including against strains that are resistant to antifungal drugs. As the studies are limited to the essential oil, the aim of this study was to evaluate the chemical, antioxidant and cytotoxic properties of polar oregano extracts and their anti-Sporothrix brasiliensis activity. Aerial plant parts were used in the preparation of 10 min (INF10) and 60 min (INF60) infusions, a decoction (DEC) and a hydroalcoholic extract (HAE). Six phenolic acids and four flavonoids were identified and quantified through liquid-chromatography (LC-MS). Extracts in increasing order of total phenolic and flavonoid contents were HAE<INF60<INF10<DEC and HAE<DEC<INF60<INF10, respectively. All extracts showed DPPH and ABTS radical scavenging potential (HAE<INF60<DEC<INF10). HAE showed the least toxicity toward MDCK and CRFK cell lines in the MTT colorimetric assay. The antifungal potential against 29 S. brasiliensis isolates obtained from cats and dogs was evaluated following the CLSI M38-A2 protocol adapted to natural products. Minimum inhibitory concentration for 50% of the isolates (MIC50) was 5 mg/ml for all extracts, and minimum fungicidal concentration for 50% of the isolates (MFC50) was 20 mg/ml for INF10 and 40 mg/ml for the remaining extracts. MIC90 was 10 mg/ml for all extracts, except for DEC (20 mg/ml). MFC90 was 40 mg/ml for INF10 and > 40 mg/ml for the other extracts. This is the first report of oregano extracts showing antifungal activity against S. brasiliensis. Its use in the treatment of sporotrichosis may be considered upon toxicity and safe-use conditions are tested.
牛至（牛至属植物）具有抗孢子丝菌属的活性，包括对耐抗真菌药物的菌株也有作用。由于相关研究仅限于精油，本研究旨在评估牛至极性提取物的化学、抗氧化和细胞毒性特性及其对巴西孢子丝菌的活性。使用植物地上部分制备10分钟（INF10）和60分钟（INF60）的浸剂、煎剂（DEC）和水醇提取物（HAE）。通过液相色谱（LC-MS）鉴定并定量了六种酚酸和四种黄酮类化合物。总酚和黄酮含量按升序排列的提取物分别为HAE<INF60<INF10<DEC和HAE<DEC<INF60<INF10。所有提取物均显示出清除DPPH和ABTS自由基的潜力（HAE<INF60<DEC<INF10）。在MTT比色法中，HAE对MDCK和CRFK细胞系的毒性最小。按照适用于天然产物的CLSI M38 - A2方案，评估了对从猫和狗身上分离出的29株巴西孢子丝菌的抗真菌潜力。所有提取物对50%分离株的最低抑菌浓度（MIC50）为5 mg/ml，INF10对50%分离株的最低杀菌浓度（MFC50）为20 mg/ml，其余提取物为40 mg/ml。除DEC（20 mg/ml）外，所有提取物的MIC90均为10 mg/ml。INF10的MFC90为40 mg/ml，其他提取物的MFC90>40 mg/ml。这是牛至提取物对巴西孢子丝菌具有抗真菌活性的首次报道。在测试其毒性和安全使用条件后，可考虑将其用于治疗孢子丝菌病。
