Nunes Camila Bontempo, Ranjan Kunal, Rodrigues Fernando Pacheco, Queiroz Marjorie de Carvalho Vieira, Marina Clara Luna Freitas, Muehlmann Luis Alexandre, Bocca Anamélia Lorenzetti, Poças-Fonseca Marcio José
Graduation Program in Animal Biology, University of Brasilia, Brasilia 70910-900, Brazil.
Amity Institute of Biotechnology, Amity University Jharkhand, Ranchi 835303, India.
Pharmaceuticals (Basel). 2025 Aug 5;18(8):1158. doi: 10.3390/ph18081158.
Actinobacteria are one of the largest bacterial phyla. These microbes produce bioactive compounds, such as antifungals, antibiotics, immunological modulators, and anti-tumor agents. Studies on actinobacteria isolated from the Brazilian Savannah biome (Cerrado) are scarce and mostly address metagenomics or the search for hydrolytic enzyme-producing microbes. (lobeira) is a tree widely employed in regional gastronomy and pharmacopeia in Central Brazil. In this work, 60 actinobacteria isolates were purified from the rhizosphere of . Eight spp. isolates were selected for in vitro antifungal activity against H99, the 89-610 fluconazole-tolerant strain, NIH198, , and . The ability of the aqueous extracts of the isolates to induce the in vitro secretion of tumor necrosis factor (TNF-α), nitric oxide (NO), interleukin-6 (IL-6), and IL-10 by murine macrophages was also evaluated. All extracts showed antifungal activity against at least two yeast species. spp. LAP11, LDB2, and LDB17 inhibited growth by 40-93%. Most extracts (except LAP2) also inhibited . None inhibited , but all inhibited (40-90%). sp. LAP8 extract increased nitric oxide production by approximately 347-fold in murine macrophages, while LDB11 extract suppressed LPS-induced TNF-α production by 70% and simultaneously increased IL-10 secretion, suggesting immunosuppressive potential. The results revealed that Cerrado actinobacteria-derived aqueous extracts are potential sources of antifungal and immunomodulatory biocompounds.
放线菌是最大的细菌门类之一。这些微生物能产生生物活性化合物，如抗真菌剂、抗生素、免疫调节剂和抗肿瘤剂。对从巴西稀树草原生物群落（塞拉多）分离出的放线菌的研究较少，且大多涉及宏基因组学或寻找产生水解酶的微生物。（洛贝拉树）是巴西中部地区美食和药典中广泛使用的一种树。在这项工作中，从洛贝拉树的根际纯化出60株放线菌分离株。选择了8株分离株对白色念珠菌H99、耐氟康唑菌株89 - 610、新生隐球菌NIH198等进行体外抗真菌活性测试。还评估了分离株水提取物诱导小鼠巨噬细胞体外分泌肿瘤坏死因子（TNF-α）、一氧化氮（NO）、白细胞介素-6（IL-6）和白细胞介素-10的能力。所有提取物对至少两种酵母菌种均表现出抗真菌活性。LAP11、LDB2和LDB17菌株对白色念珠菌的生长抑制率为40% - 93%。大多数提取物（LAP2除外）也抑制新生隐球菌的生长。没有提取物能抑制热带念珠菌的生长，但所有提取物都能抑制近平滑念珠菌的生长（40% - 90%）。LAP8菌株的提取物使小鼠巨噬细胞中的一氧化氮产量增加了约347倍，而LDB11菌株的提取物将脂多糖诱导的TNF-α产量抑制了70%，同时增加了IL-10的分泌，表明具有免疫抑制潜力。结果表明，源自塞拉多放线菌的水提取物是抗真菌和免疫调节生物化合物的潜在来源。
