Department of Biosciences and Oral Diagnosis, Laboratory of Microbiology and Immunology, Institute of Science and Technology, Univ Estadual Paulista/UNESP, Av, Engenheiro Francisco José Longo, 777-Jardim São Dimas, São José dos Campos, SP, Brazil.
BMC Complement Altern Med. 2013 Aug 15;13:208. doi: 10.1186/1472-6882-13-208.
With the emergence of strains resistant to conventional antibiotics, it is important to carry studies using alternative methods to control these microorganisms causing important infections, such as the use of products of plant origin that has demonstrated effective antimicrobial activity besides biocompatibility. Therefore, this study aimed to evaluate the antimicrobial activity of plant extracts of Equisetum arvense L., Glycyrrhiza glabra L., Punica granatum L. and Stryphnodendron barbatimam Mart. against Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus mutans, Candida albicans, Candida tropicalis, and Candida glabrata, and to analyze the cytotoxicity of these extracts in cultured murine macrophages (RAW 264.7).
Antimicrobial activity of plant extracts was evaluated by microdilution method based on Clinical and Laboratory Standards Institute (CLSI), M7-A6 and M27-A2 standards. The cytotoxicity of concentrations that eliminated the microorganisms was evaluated by MTT colorimetric method and by quantification of proinflammatory cytokines (IL-1β and TNF-α) using ELISA.
In determining the minimum microbicidal concentration, E. arvense L., P. granatum L., and S. barbatimam Mart. extracts at a concentration of 50 mg/mL and G. glabra L. extract at a concentration of 100 mg/mL, were effective against all microorganisms tested. Regarding cell viability, values were 48% for E. arvense L., 76% for P. granatum L, 86% for S. barbatimam Mart. and 79% for G. glabra L. at the same concentrations. About cytokine production after stimulation with the most effective concentrations of the extracts, there was a significant increase of IL-1β in macrophage cultures treated with S. barbatimam Mart. (3.98 pg/mL) and P. granatum L. (7.72 pg/mL) compared to control (2.20 pg/mL) and a significant decrease of TNF-α was observed in cultures treated with G. glabra L. (4.92 pg/mL), S. barbatimam Mart. (0.85 pg/mL), E. arvense L. (0.83 pg/mL), and P. granatum L. (0.00 pg/mL) when compared to control (41.96 pg/mL).
All plant extracts were effective against the microorganisms tested. The G. glabra L. extract exhibited least cytotoxicity and the E. arvense L. extract was the most cytotoxic.
随着对抗生素的传统菌株的出现，使用替代方法来控制这些引起重要感染的微生物非常重要，例如使用植物来源的产品，这些产品已被证明具有有效的抗菌活性和生物相容性。因此，本研究旨在评估木贼（Equisetum arvense L.）、甘草（Glycyrrhiza glabra L.）、石榴（Punica granatum L.）和巴西苏木（Stryphnodendron barbatimam Mart.）植物提取物对金黄色葡萄球菌、表皮葡萄球菌、变形链球菌、白色念珠菌、热带念珠菌和光滑念珠菌的抗菌活性，并分析这些提取物在培养的鼠巨噬细胞（RAW 264.7）中的细胞毒性。
采用微量稀释法，根据临床和实验室标准协会（CLSI）M7-A6 和 M27-A2 标准，评价植物提取物的抗菌活性。采用 MTT 比色法和 ELISA 法测定消除微生物的浓度的细胞毒性，测定促炎细胞因子（IL-1β 和 TNF-α）的含量。
在确定最小杀菌浓度时，浓度为 50mg/ml 的木贼（Equisetum arvense L.）、石榴（Punica granatum L.）和巴西苏木（Stryphnodendron barbatimam Mart.）提取物以及浓度为 100mg/ml 的甘草（Glycyrrhiza glabra L.）提取物对所有测试的微生物均有效。关于细胞活力，浓度为 50mg/ml 的木贼（Equisetum arvense L.）、浓度为 76%的石榴（Punica granatum L.）、浓度为 86%的巴西苏木（Stryphnodendron barbatimam Mart.）和浓度为 79%的甘草（Glycyrrhiza glabra L.）提取物的细胞活力值为 48%。关于刺激后细胞因子的产生，与对照组（2.20pg/ml）相比，用最有效的提取物浓度处理的巨噬细胞培养物中 IL-1β 的产生显著增加，用巴西苏木（Stryphnodendron barbatimam Mart.）（3.98pg/ml）和石榴（Punica granatum L.）（7.72pg/ml）提取物处理的培养物中 IL-1β 的产生显著增加，而用甘草（Glycyrrhiza glabra L.）、巴西苏木（Stryphnodendron barbatimam Mart.）、木贼（Equisetum arvense L.）和石榴（Punica granatum L.）提取物处理的培养物中 TNF-α 的产生显著降低，与对照组（41.96pg/ml）相比，用甘草（Glycyrrhiza glabra L.）（4.92pg/ml）、巴西苏木（Stryphnodendron barbatimam Mart.）（0.85pg/ml）、木贼（Equisetum arvense L.）（0.83pg/ml）和石榴（Punica granatum L.）（0.00pg/ml）提取物处理的培养物中 TNF-α 的产生显著降低。
所有植物提取物均对测试的微生物有效。甘草（Glycyrrhiza glabra L.）提取物的细胞毒性最小，木贼（Equisetum arvense L.）提取物的细胞毒性最大。
