Effect of 2,5-dimethylpyrazine on uterine contraction in late stage of pregnant female rats

Study on the enhanced efficacy mechanism of vinegar-processed Cyperus rotundus in the treatment of primary dysmenorrhea

The enhanced efficacy of vinegar-processed Cyperus rotundus (VCR) in treating primary dysmenorrhea (PD) has been observed. However, the active components and potential mechanisms of synergy are still unclear. The objective of this study was to develop a method that combines bionic technology, plant metabolomics and network pharmacology to discover the active components and potential mechanisms underlying the enhanced therapeutic effects of VCR for PD. Vinegar processing alters the flavor of C. rotundus, leading to changes in its properties. The acidic nature of vinegar enhances the selectivity of the medicine toward the liver, thereby improving its ability to soothe the liver, regulate qi and provide pain relief. Through gas chromatography-mass spectrometry and multivariate statistical analysis, 30 key differential components between raw C. rotundus and VCR have been screened and identified. These differential components primarily exert their therapeutic effects in treating PD by modulating targets such as interleukin-6, TNF, TP53 and PTGS2, as well as pathways including the estrogen signaling pathway, ovarian steroidogenesis, the TNF signaling pathway and the HIF-1 signaling pathway. The findings of this study serve as a reference for the application of VCR in compound formulas and clinic practiceal. Furthermore, the methodology employed in this study provides research insights for the processing of other Chinese medicines.

Engineering Escherichia coli for high-yielding 2,5-Dimethylpyrazine synthesis from L-Threonine by reconstructing metabolic pathways and enhancing cofactors regeneration

2,5-Dimethylpyrazine (2,5-DMP) is important pharmaceutical raw material and food flavoring agent. Recently, engineering microbes to produce 2,5-DMP has become an attractive alternative to chemical synthesis approach. In this study, metabolic engineering strategies were used to optimize the modified Escherichia coli BL21 (DE3) strain for efficient synthesis of 2,5-DMP using L-threonine dehydrogenase (EcTDH) from Escherichia coli BL21, NADH oxidase (EhNOX) from Enterococcus hirae, aminoacetone oxidase (ScAAO) from Streptococcus cristatus and L-threonine transporter protein (EcSstT) from Escherichia coli BL21, respectively. We further optimized the reaction conditions for synthesizing 2,5-DMP. In optimized conditions, the modified strain can convert L-threonine to obtain 2,5-DMP with a yield of 2897.30 mg/L. Therefore, the strategies used in this study contribute to the development of high-level cell factories for 2,5-DMP.

Integrating LC-MS and HS-GC-MS for the metabolite characterization of the Chinese medicinal plant Platostoma palustre under different processing methods

Platostoma palustre (or Mesona chinensis Benth) is an important medicinal and edible plant in China and Southeast Asian countries. To study the effects of different processing methods on the quality, nutrition, and flavor of P. palustre, we adopted the LC-MS and HS-GC-MS to compare the influences of tedding (S), sweating (M), and drying (H) on the metabolites and volatile substances of P. palustre. Biochemical determinations revealed that the M treatment could promote the accumulation of the contents of total sugar, soluble sugar, and total pectin compared with the H and S treatments but decrease the total flavonoid contents. LC-MS and HS-GC-MS uncovered 98 differential metabolites and 27 differential volatile substances among the three treatments, respectively. Overall, the M treatment facilitated the stabilization and improvement of the quality of polysaccharides and volatile substances, while the H treatment could promote the level of amino acids in P. palustre. The current study provided a theoretical reference for establishing standardized processing methods and sustaining the quality stability of P. palustre in future.

2-Ethylpyrazine Induces Vasodilatation by Releasing Nitric Oxide in the Endothelium

Oxygen transportation and regulation of some physiological processes are facilitated by blood flow. Furthermore, blood flow is regulated by various factors such as nitric oxide (NO) and the autonomic nerve system. In modern life, many people suffer from chilliness (hiesho) because of mental stress and an excessive use air-conditioning systems, which induces vasoconstriction in the peripheral skin. In this study, we focused on pyrazine derivatives, particularly compounds that are used as food flavoring materials, and investigated their effects on vascular function and blood flow. We examined the vasodilatory effect of pyrazine derivatives in the rat thoracic aorta and found 2-ethylpyrazine (2-EP) to be the most active pyrazine compound. Additionally, we found that 2-EP induces vasodilatation through the activities of endothelium-derived relaxing factors. 2-EP activates NO synthesis through the effect of endothelial NO synthase in the endothelium. As a result, cyclic GMP levels rise in smooth muscle cells and vasodilatation is induced. We also confirmed that 2-EP increases peripheral blood flow in rats. From these results, we concluded that 2-EP induces vasodilatation by inducing the release of NO and increasing peripheral blood flow.