Antibacterial activity and mechanism of luteolin isolated from Lophatherum gracile Brongn. against multidrug-resistant Escherichia coli.

Infections caused by multidrug-resistant (MDR) bacteria have become a major challenge for global healthcare systems. The search for antibacterial compounds from plants has received increasing attention in the fight against MDR bacteria. As a medicinal and edible plant, Lophatherum gracile Brongn. (L. gracile) has favorable antibacterial effect. However, the main antibacterial active compound and its antimicrobial mechanism are not clear. Here, our study first identified the key active compound from L. gracile as luteolin. Meanwhile, the antibacterial effect of luteolin was detected by using the broth microdilution method and time-kill curve analysis. Luteolin can also cause morphological structure degeneration and content leakage, cell wall/membrane damage, ATP synthesis reduction, and downregulation of mRNA expression levels of sulfonamide and quinolones resistance genes in multidrug-resistant Escherichia coli (MDR E. coli). Furthermore, untargeted UPLC/Q-TOF-MS-based metabolomics analysis of the bacterial metabolites revealed that luteolin significantly changed riboflavin energy metabolism, bacterial chemotaxis cell process and glycerophospholipid metabolism of MDR E. coli. This study suggests that luteolin could be a potential new food additive or preservative for controlling MDR E. coli infection and spread.

Optimization of ultrasound-assisted extraction based on response surface methodology using HPLC-DAD for the analysis of red clover (Trifolium pretense L.) isoflavones and its anti-inflammatory activities on LPS-induced 3D4/2 cell.

Introduction: Trifolium pratense L. has anti-inflammatory, antioxidant, cardiovascular disease prevention, and estrogen-like effects. The existing method for the assay of effective components is commonly based on a spectrophotometer, which could not meet the requirement of quality control. Furthermore, although there have been many studies on the anti-inflammation effect of red clover, a few have been reported on the regulatory effect of red clover isoflavones (RCI) on lipopolysaccharide (LPS)-induced inflammatory response in porcine alveolar macrophages (3D4/2 cells), and its mechanism of action is still unclear. Methods: The main components of RCI including daidzein, genistein, and biochanin A were accurately quantified by high-performance liquid chromatography coupled with diode array detection (HPLC-DAD) after optimizing the extraction process through response surface methodology. The anti-inflammatory potential of RCI was carried out by detecting the level of inflammatory cytokines and mRNA expression of related genes. Furthermore, its anti-inflammatory mechanism was explored by investigating two signaling pathways (NF-κB and MAPK). Results: The optimal extraction conditions of RCI were as follows: the concentration of ethanol is 86% and the solid-liquid ratio is 1:29, with the herb particle size of 40 mesh sieve. Under the optimal conditions, the total extraction of target components of RCI was 2,641.469 µg/g. The RCI could significantly suppress the production and expression of many pro-inflammatory cytokines. The results of the Western blot revealed that RCI dramatically reduced the expression of p65, p-p65, IκB-α, p38, and p-p38. These results are associated with the suppression of the signal pathway of p38 MAPK, and on the contrary, activating the NF-κB pathway. Collectively, our data demonstrated that RCI reversed the transcription of inflammatory factors and inhibited the expression of p65, p-p65, IκB-α, and p38, indicating that RCI had excellent anti-inflammatory properties through disturbing the activation of p38 MAPK and NF-κB pathways. Conclusion: The extraction conditions of RCI were optimized by HPLC-DAD combined with response surface methodology, which will contribute to the quality control of RCI. RCI had anti-inflammatory effects on the LPS-induced 3D4/2 cells. Its mechanism is to control the activation of NF-κB and p38 MAPK pathways, thereby reducing the expression of inflammatory-related genes and suppressing the release of cytokines.

[CA 125 expression in cervical and vaginal secretions in women in normal reproductive period].

OBJECTIVE: To investigate the tumor-associated antigen CA125 expression in the serum and cervical and vaginal secretions in women during normal reproductive period, and explore the clinical value of detecting tumor markers in the cervical and vaginal secretions. METHODS: A total of 145 women in reproductive period were divided into 3 age groups (20-29 years, 30-39 years, and over 40 years), and their CA125 levels in cervical secretion, vaginal secretion and serum were detected by automatic electro-chemiluminescent immunoassay. RESULTS: CA125 levels in the cervical secretion, vaginal secretion and serum showed no significant difference between the 3 age groups (P>0.05). In each group, CA125 levels differed significantly between the cervical secretion, vaginal secretion and serum (P<0.001). In the 145 women, the average CA125 level was 497.82 - or + 75.29 U/ml in the cervical secretion, 114.66 - or + 26.40 U/ml in vaginal secretion and 18.06 - or + 3.35 U/ml in serum, showing significant differences between them (P<0.001). CONCLUSION: CA125 expression level is significantly higher in the cervical and vaginal secretions than in the serum in women in normal reproductive period, and its levels in cervical and vaginal secretions can be more sensitive and convenient for early detection of related diseases.