Awad Mohamed A, Mahgoub Shahenda, Soliman Hesham S M, Hammad Sherif F
Biotechnology Program, Institute of Basic and Applied Science, Egypt-Japan University of Science and Technology (E-JUST), New Borg El-Arab City, Alexandria, 21934, Egypt.
Botany and Microbiology Department, Faculty of Science, Sohag University, Sohag, 82524, Egypt.
BMC Complement Med Ther. 2025 Apr 26;25(1):160. doi: 10.1186/s12906-025-04879-x.
Rhizosphere bacteria were considered a prospective reservoir of bioactive compounds with significant pharmacological efficacy.
From the rhizosphere of Datura metel L., Bacillus velezensis DM was isolated and characterized using 16 S rRNA. PCR screening and sequencing were conducted to identify genes related to bioactive metabolite production. The extraction of secondary metabolites from the bacterial strain was performed via a fermentation process. The ethyl acetate extract of the propagated strain was subjected to fractionation and purification through various chromatographic techniques. The characterization of the isolated compounds was accomplished using different spectroscopic methods, such as 1D and 2D-NMR. An MTT test was conducted to assess the cytotoxic activity of bacterial extract on MCF-7, HepG-2, and HCT-116 cells. Furthermore, its pure compound (1) was tested for its cytotoxicity on HCT-116 and a normal cell (THLE2) to test its safety for normal cells. Apoptosis was identified through flow cytometry on HCT-116 cells after double-staining with PI and annexin V-FITC. The antioxidant action of bacterial extract was assessed through DPPH and ABTS assays. Furthermore, anti-inflammatory evaluations were carried out employing lipoxygenase (5-LOX) and cyclooxygenase (COX-2) inhibition.
The NCBI GenBank database has effectively incorporated the 16 S rRNA gene sequence of Bacillus velezensis DM under the accession number OR364492. Polyketide synthase and two lipopeptide genes for surfactin and iturin A were effectively detected by PCR, and their sequences were included in the Genbank database. A novel compound, 5,6-di(methylamino)hex-5-ene-1,2,3-triol (1), was successfully separated from the strain. Bacterial extract demonstrated significant cytotoxic activity against the evaluated cancer cells, exhibiting the most pronounced effect on HCT-116 cells. Compound (1) showed promising cytotoxic potential against HCT-116 cells with a higher selectivity index (2.5) towards cancer cells in comparison to Doxorubicin (1.49). Apoptosis assay showed that bacterial extract caused apoptosis about 14 folds compared to the control HCT-116 cells. Furthermore, it showed a potent anti-inflammatory outcome (IC = 1.927 µg/mL) and antioxidant activity at IC of 76.8 µg/mL.
This study revealed the possible pharmacological effects of secondary metabolites generated by Bacillus velezensis DM, making it a valuable resource for isolating bioactive compounds with potential therapeutic and biomedical uses.
根际细菌被认为是具有显著药理功效的生物活性化合物的潜在来源。
从曼陀罗的根际分离出贝莱斯芽孢杆菌DM，并使用16S rRNA进行鉴定。进行PCR筛选和测序以鉴定与生物活性代谢物产生相关的基因。通过发酵过程从该细菌菌株中提取次生代谢物。通过各种色谱技术对繁殖菌株的乙酸乙酯提取物进行分离和纯化。使用不同的光谱方法，如1D和2D-NMR，对分离出的化合物进行表征。进行MTT试验以评估细菌提取物对MCF-7、HepG-2和HCT-116细胞的细胞毒性活性。此外，测试其纯化合物（1）对HCT-116和正常细胞（THLE2）的细胞毒性，以测试其对正常细胞的安全性。在用PI和膜联蛋白V-FITC双重染色后，通过流式细胞术在HCT-116细胞上鉴定凋亡。通过DPPH和ABTS试验评估细菌提取物的抗氧化作用。此外，采用脂氧合酶（5-LOX）和环氧化酶（COX-2）抑制进行抗炎评估。
NCBI GenBank数据库已有效地将贝莱斯芽孢杆菌DM的16S rRNA基因序列纳入，登录号为OR364492。通过PCR有效地检测到聚酮合酶以及用于表面活性素和伊枯草菌素A的两个脂肽基因，其序列已包含在Genbank数据库中。从该菌株中成功分离出一种新型化合物5,6-二（甲氨基）己-5-烯-1,2,3-三醇（1）。细菌提取物对所评估的癌细胞表现出显著的细胞毒性活性，对HCT-116细胞的作用最为明显。化合物（1）对HCT-116细胞显示出有前景的细胞毒性潜力，与阿霉素（1.49）相比，对癌细胞具有更高的选择性指数（2.5）。凋亡试验表明，与对照HCT-116细胞相比，细菌提取物引起的凋亡约为14倍。此外，它显示出有效的抗炎效果（IC = 1.927μg/mL），在IC为76.8μg/mL时具有抗氧化活性。
本研究揭示了贝莱斯芽孢杆菌DM产生的次生代谢物可能的药理作用，使其成为分离具有潜在治疗和生物医学用途的生物活性化合物的宝贵资源。
