Pharmacognosy Department, College of Pharmacy, October University for Modern Sciences and Arts (MSA), 6th of October City, Giza 12566, Egypt.
Department of Molecular Systems Biology, Helmholtz-Centre for Environmental Research-UFZ GmbH, 04318 Leipzig, Germany.
Molecules. 2022 Nov 4;27(21):7568. doi: 10.3390/molecules27217568.
biological effects are attributed to several bioactive metabolites. However, these actions could be altered in vivo by biotransformation reactions mainly via gut microbiota. This study assessed gut microbiota effect on the biotransformation of metabolites both in vitro and ex vivo. Two-time aliquots (0.5 and 24 h) from the in vitro assay were harvested post incubation of methanol extract with microbial consortium, while untreated and treated samples with fecal bacterial culture from the ex vivo assay were prepared. Metabolites were analyzed using UHPLC-QTOF-MS, with flavonoid glycosides completely hydrolyzed in vitro at 24 h being converted to two major metabolites, 3-(4-hydroxyphenyl)propanoic acid and phloroglucinol, concurrent with an increase in the gallic acid level. In case of the ex vivo assay, detected flavonoid glycosides in untreated sample were completely absent from treated counterpart with few flavonoid aglycones and 3-(4-hydroxyphenyl)propanoic acid in parallel to an increase in piscidic acid. In both assays, fatty and organic acids were completely hydrolyzed being used as energy units for bacterial growth. Chemometric tools were employed revealing malic and (iso)citric acids as the main discriminating metabolites in vitro showing an increased abundance at 0.5 h, whereas in ex vivo assay, (iso)citric, aconitic and mesaconic acids showed an increase at untreated sample. Piscidic acid was a significant marker for the ex vivo treated sample. DPPH, ORAC and FRAP assays were further employed to determine whether these changes could be associated with changes in antioxidant activity, and all assays showed a decline in antioxidant potential post biotransformation.
生物效应归因于几种生物活性代谢物。然而，这些作用可能会在体内通过生物转化反应发生改变，主要是通过肠道微生物群。本研究评估了肠道微生物群对代谢物生物转化的影响，包括体外和离体研究。在甲醇提取物与微生物联合体孵育后，分别从体外试验的两个时间点（0.5 小时和 24 小时）采集样品，而未处理和用粪便细菌培养物处理的样本来自离体试验。使用 UHPLC-QTOF-MS 分析代谢物，体外孵育 24 小时后，黄酮糖苷完全水解，转化为两种主要代谢物，3-(4-羟苯基)丙酸和邻苯三酚，同时增加了没食子酸的水平。在离体试验中，未处理样本中检测到的黄酮糖苷完全不存在于处理样本中，只有少量黄酮苷元和 3-(4-羟苯基)丙酸，同时鱼尿酸水平增加。在两种试验中，脂肪酸和有机酸完全水解，被用作细菌生长的能量单位。化学计量学工具的应用表明，体外试验中，苹果酸和（异）柠檬酸是主要的区分代谢物，在 0.5 小时时丰度增加，而在离体试验中，未处理样本中（异）柠檬酸、乌头酸和mesaconic 酸的丰度增加。鱼尿酸是离体处理样本的一个重要标志物。进一步采用 DPPH、ORAC 和 FRAP 测定这些变化是否与抗氧化活性的变化有关，所有测定均显示生物转化后抗氧化潜力下降。
