Larch bark procyanidins (LBPCs) have not only antioxidant and antitumor properties, but also strong bacteriostatic effects. However, it is not clear about the antibacterial mechanisms of LBPC. In this work, the antibacterial effects and mechanisms of LBPC on Staphylococcus aureus were studied in the aspects of morphological structure, cell wall and membrane, essential proteins, and genetic material. The results showed that LBPC effectively inhibited bacterial growth at a minimum inhibitory concentration of 1.75 mg/ml. Bacterial morphology was significantly altered by LBPC treatment, with the cell walls and membranes being destroyed. Extracellular alkaline phosphatase content, bacterial fluid conductivity, and Na+/K+-ATPase and Ca2+-ATPase activities in the membrane system were all increased. In the energy metabolic systems, the activities of succinate dehydrogenase, malate dehydrogenase, and adenosine triphosphatase (ATPase) were all decreased, resulting in a slowdown of metabolism and bacterial growth inhibition. Changes of protein content and composition in the bacteria suggested that the protein expression system was affected. In addition, LBPC was found to bind to DNA grooves to form complexes. Thus, LBPC has a very strong inhibitory effect on S. aureus and can kill S. aureus by destroying the integrity and permeability of the cell wall and cell membrane, affecting protein synthesis, and binding to DNA.

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Background Acne is a multifactorial skin disorder frequently observed during adolescence with different grades of severity. The crucial factors of acne are the increase of lipids secretion and the change of composition on the skin surface lipid (SSL). However, there are no studies on the changes of lipid composition and content between different grades of adolescent acne in lesional skin and nonlesionsal skin. Aims This study was to investigate correlation in the composition of SSL and different grades in order to understand the tendency of SSL alterations in this disease for successful acne management and prevention. Methods A powerful analytical technique, UPLC‐QTOF‐MS, and multivariate data analysis were used to investigate SSL variations of lipid main classes, subclasses, and species. Results The results indicated that sphinganine, triradylglycerols (TG), and phytosphingosine were important in adolescent acne development. The average fatty acids (FAs) chain length in patients with acne showed significantly shortened trend from mild to moderate adolescent acne. Additionally, the relative average content of TG, diglyceride (DG), FA, ceramides (Cers), and the level of unsaturated FAs significantly increased from mild to moderate adolescent acne. Interestingly, our results demonstrated that the phytosphingosine and sphinganine showed an increasing trend in mild acne groups, but decreasing trend in lesional skin of moderate group. Conclusions Lipidomics analysis suggested that the variation of TG, phytosphingosine, and sphinganine was closely related to the occurrence severity of acne in adolescent.

Vine tea (Ampelopsis grossedentata) has been approved as a new food ingredient in 2013. Both vine tea extract (VTE) and its active ingredient, 2R, 3R-Dihydromyricetin (DMY), showed good antibacterial activity. The mechanism of VTE and DMY against Staphylococcus aureus were evaluated by morphology observation, cell membrane and wall assay, protein assay, and DNA assay in this study. The results of SEM and TEM revealed that the VTE and DMY changed the morphology of S. aureus. The leakage of AKPase and β-galactosidase in treated groups demonstrated that the membrane integrity of S. aureus was disrupted. Meanwhile, the results of protein assay showed that VTE and DMY inhibited the expression of total proteins, and decreased activities of a few energy metabolism enzymes, total ATPase. Moreover, spectral and competitive analysis revealed that VTE and DMY interacted with DNA by groove and intercalation binding. Finally, the suspension experiments of Chinese cabbage and barley showed that inhibitors had strong inhibitory effect on bacteria growth. Overall, the results suggested that VTE and DMY may be potential food preservatives for inhibiting pathogen.

Waxy maize is prevalently grown in China and other countries due to the excellent characters and economic value. However, its low content of lysine can’t meet the nutritional requirements of humans and livestock. In the present study, we introgressed the opaque2 (o2) allele into waxy maize line Zhao OP-6/O2O2 by using marker-assisted selection (MAS) technique and successfully improved the lysine content and quality of waxy maize. Transcript abundance analysis indicated that the wx1 expression levels had no difference between Zhao OP-6/o2o2 and Zhao OP-6/O2O2. However, Zhao OP-6/o2o2 was characterized by a phenotype of hard and vitreous kernels and accumulation of protein bodies at smaller size (one third of that of parents) but in larger numbers. Biochemical analyses showed that Zhao OP-6/o2o2 had 16.7% less free amino acids than Zhao OP-6/O2O2, especially those derived from glycolytic intermediates, but its content of lysine was increased by 51.6% (0.47% vs. 0.31%). The content of amylopectin was 98.5% in Zhao OP-6/o2o2, significantly higher than that in Zhao OP-6/O2O2 (97.7%). Proteomic analyses indicated that o2 introgression not only decreased the accumulation of various zein proteins except for 27-kDa γ-zein, but also affected other endosperm proteins related to amino acid biosynthesis, starch-protein balance, stress response and signal transduction. This study gives us an intriguing insight into the metabolism changes in endosperm of waxy maize introgressed with opaque2.

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Background: The microbiological basis of diaper dermatitis has not been clearly elucidated; however, a better understanding of microbial colonization may be vital for developing appropriate therapies. Methods: Using 16S-rRNA gene sequencing technology, we characterized and compared the bacterial communities obtained from the buttock skin sites of children with diaper dermatitis and from healthy controls. Bacterial diversity in the buttock lesion area and subsequent recovery after emollient treatment have been discussed herein. Results: In buttock skin of children with or without diaper dermatitis, Staphylococcus and Anaerococcus were predominant in the total skin microbiome. Compared with the healthy group, the overall skin bacterial richness and diversity were higher in children with diaper dermatitis, with the abundance of Proteobacteria being significantly higher. In the diaper dermatitis group, the richness of Enterococcus, Erwinia and Pseudomonas was significantly higher, and the levels of Clostridium and Actinomyces were significantly lower than those in healthy children. Richness of Staphylococcus aureus was significantly higher in the diaper dermatitis group, whereas that of Staphylococcus epidermidis and Bifidobacterium longum was lower. Staphylococcus epidermidis and Staphylococcus haemolyticus, the dominant species found in buttock skin, were observed to recover earlier after the disease had improved through emollient treatment. Conclusion: Staphylococcus epidermidis, as skin probiotic bacterium, and B longum, Clostridium butyricum and Lactobacillus ruminis, which are intestinal probiotic bacteria, are significantly decreased in diaper dermatitis lesions. These changes in the buttock skin microflora indicate an imbalance in the microflora and suggest that the intestinal microflora may be undergoing dynamic changes. The results of this study suggest that probiotic bacterial supplementation may be useful in the treatment and prevention of diaper dermatitis.