Jobe Martha Cebile, Mwanza Mulunda
Department of Animal Health, North-West University, Mahikeng Campus, Mmabatho, Mahikeng, South Africa.
Food Security and Safety Focus Area, North-West University, Mahikeng Campus, Mmabatho, Mahikeng, South Africa.
PLoS One. 2025 Apr 24;20(4):e0320454. doi: 10.1371/journal.pone.0320454. eCollection 2025.
Food crops contaminated with Aspergillus flavus due to aflatoxins can be hazardous for both humans and animals, hence endeavours are being explored to find natural antifungals to combat the contamination and mycotoxin issue. The current study used the agar dilution method to assess the effect of Urginea epigea methanolic extract and biosynthesized silver-zinc oxide nanoparticles on the toxigenic strain of Aspergillus. In the experiment, an aflatoxin-producing strain was used, and potato dextrose agar was diluted with methanolic extract from U. epigea and silver/zinc oxide nanoparticles at concentrations of 0, 6.5, 12, 25, and 50 mg/mL, respectively. Mycelia growth diameters were measured to test inhibitory activity. A significant decrease in fungal growth was observed at different concentrations (P < 0,05) when compared to the control. At 50 mg/mL, the extract of U. epigea significantly reduced the growth of A. flavus by 100%. PCR data shows that the expression of aflD and aflR was significantly downregulated (P < 0.005) by the treatments, with U. epigea having a 50fold decrease when compared to Ag/ZnO nanoparticles. Compared to the controls, Ag/ZnO nanoparticles down-regulated the expression of aflD and aflR in A. flavus by more than 30-fold. However, there was less expression by nanoparticles, as evidenced by the sequence alignment. A. flavus growth and aflatoxin B1 production were both considerably suppressed by U. epigea methanolic extract, through the presence of phytochemicals thus has the potential to be employed as an alternative antifungal agent to control aflatoxigenic fungus. The study recommends investigating and extracting the active compound present in the U. epigea bulb.
受黄曲霉污染而产生黄曲霉毒素的粮食作物对人类和动物都有危害，因此人们正在努力寻找天然抗真菌剂来应对污染和霉菌毒素问题。当前的研究采用琼脂稀释法评估了绵枣儿甲醇提取物和生物合成的银-氧化锌纳米颗粒对黄曲霉产毒菌株的影响。在实验中，使用了一株产黄曲霉毒素的菌株，并用绵枣儿甲醇提取物和浓度分别为0、6.5、12、25和50mg/mL的银/氧化锌纳米颗粒稀释马铃薯葡萄糖琼脂。测量菌丝体生长直径以测试抑制活性。与对照相比，在不同浓度下观察到真菌生长显著下降（P<0.05）。在50mg/mL时，绵枣儿提取物使黄曲霉的生长显著降低了100%。PCR数据表明，处理后aflD和aflR的表达显著下调（P<0.005），与银/氧化锌纳米颗粒相比，绵枣儿提取物使表达下降了50倍。与对照相比，银/氧化锌纳米颗粒使黄曲霉中aflD和aflR的表达下调了30倍以上。然而，如序列比对所示，纳米颗粒的表达较少。绵枣儿甲醇提取物通过植物化学物质的存在显著抑制了黄曲霉的生长和黄曲霉毒素B1的产生，因此有潜力用作控制产黄曲霉毒素真菌的替代抗真菌剂。该研究建议对绵枣儿鳞茎中存在的活性化合物进行研究和提取。
