Fluorescent probe were used to evaluate the effects of catechin on the structural parameters (annular lipid fluidity, transbilayer lateral and rotational mobility and protein clustering) of the Porphyromonas gingivalis outer membrane (OPGs). An experimental procedure was used on the basis of selective quenching of 1,6-diphenyl-1,3,5-hexatriene (DPH) and 1,3-di(1-pyrenyl)propane (Py-3-Py) by trinitrophenyl groups and radiationless energy transfer from the tryptophans of membrane proteins to Py-3-Py and DPH. Catechin increased the bulk lateral and rotational mobility, annular lipid fluidity of OPGs lipid bilayers, and had greater fluidizing efficacy on the outer monolayer than the inner monolayer. It also caused membrane proteins to cluster. Based on these effects of catechin on OPGs, the antibacterial and antiviral actions of catechin can be partially explained.
Chlorhexidine is a cationic bisbiguanide with broad antibacterial activity, and diverse activity encompassing gram-positive and gram-negative bacteria, yeasts, dermatophytes, and some lipophilic viruses. Chlorhexidine alters the permeability of the bacterial membrane. They also neutralize periodontal pathogens such as Streptococcus aureus, Porphyromonas gingivalis, and Prevotella intermedia. Porphyromonas gingivalis were cultured to isolate the Porphyromonas gingivalis outer membranes (OPG). Also, OPG were used to prepare large unilamellar liposomes with total lipids (OPGTL) extracted and prepared with the phospholipids mixture (PL). The effect of chlorhexidine digluconate on cell membrane kinetic changes was investigated using fluorescence polarization of n-(9-anthroyloxy) stearic acid with different rotational mobility depending on the probe substitution position (n) in the membrane phospholipid aliphatic chain. Chlorhexidine digluconate increased the hydrocarbon rotational mobility interior of the OPG, OPGTL and PL, but native and model membranes interfacial mobility were decreased. The sensitivity to increasing chlorhexidine digluconate effect on rotational mobility was proportional to the depth of probe position in descending order of 16-AP, 12-AS, 6-AS and 9-AS. Chlorhexidine digluconate disordering or ordering the effects on the membrane lipids may cause its bacteriostatic and bacteriocidal actions.
Resveratrol has been reported to exert anticancer activity via modulation of multiple pathways and genes. In this study, we examined the effect of resveratrol on YD-10B human oral squamous cell carcinoma cells and its molecular mechanisms of action. We found that resveratrol inhibited the proliferation of YD-10B cells in a dose- and timedependent manner. The suppressive effect of resveratrol was accompanied by a reduction in Bmi-1 gene expression. We observed that silencing the Bmi-1 gene by small interfering RNA effectively downregulated the levels of GLUT1 mRNA and protein, which were also repressed by resveratrol. Bmi-1 silencing increased the number of YD-10B cells in S-phase arrest by approximately 2.3-fold compared with the control. In conclusion, the results of the present study demonstrate, for the first time, that resveratrol suppresses Bmi-1-mediated GLUT1 expression in human oral squamous cell carcinoma cells and suggest that the specific molecular targeting of Bmi-1 and/or GLUT1 expression can be combined with a chemotherapeutic strategy to improve the response of oral cancer cells to resveratrol.
Herbal medicine has been the basis for medical treatments through much of human history, and such traditional medicine is still widely practiced today. Modern medicine makes use of many plant-derived compounds as the basis for pharmaceutical drugs. In traditionally, Achyranthes aspera, Safflower (Carthamus tinctorius) seed and Acanthopanax senticosus have been used for the treatment and prevention of bone-related diseases. In this study, we investigated the pharmacological effect of mixture of Achyranthes aspera, Safflower (Carthamus tinctorius) seed and Acanthopanax senticosus and the other herbs. Two types of enzymes were used to enhance the extraction components of amino acid, mineral content, free sugar, and flavor recovery in extracting natural herbal mixtures(NME). We evaluated regulation of osteogenic differentiation in human bone marrow mesenchymal stem cells using alkaline phosphatase staining, alizarin red S staining and RT-PCR. The CCK-8 assay indicated that NME had no cytotoxicity but increased cell survival. In addition, NME promoted the mineralization and expression of osteogenic differention marker genes in human bone marrow mesenchymal stem cells. Therefore, NME has an effect of promoting proliferation and osteogenic differentiation of human mesenchymal stem cell.
The aim of this study was to provide a basis for the molecular mechanism underlying the pharmacological action of ethanol. We studied the effects of 1-propanol on the location of n-(9-anthroyloxy)palmitic acid or stearic acid (n-AS) within the phospholipids of synaptosomal plasma membrane vesicles (SPMV). The SPMV were isolated from the bovine cerebral cortex and liposomes of total lipids (SPMVTL) and phospholipids (SPMVPL). 1-Propanol increased the rotational mobility of inner hydrocarbons, while decreasing the mobility of membrane interface, in native and model membranes. The degree of rotational mobility varied with the number of carbon atoms at positions 16, 12, 9, 6 and 2 in the aliphatic chain of phospholipids in the neuronal and model membranes. The sensitivity of increasing or decreasing rotational mobility of hydrocarbon interior or surface by 1-propanol varied with the neuronal and model membranes in the following order: SPMV, SPMVPL and SPMVTL.
Although anti-aging activities of melatonin, a hormone secreted by the pineal gland, have been reported in senescence-accelerated mouse models and several types of cells, its impact and mechanism on the senescence of human dental pulp cells (HDPCs) remains unknown. In this study, we examined the impact of melatonin on cellular premature senescence of HDPCs. Here, we found that melatonin markedly inhibited senescent characteristics of HDPCs after exposure to hydrogen peroxide (H2O2), including the increase in senescence-associated β-galactosidase (SA-β-gal)-positive HDPCs and the upregulation of p21 protein, an indicator for senescence. In addition, as melatonin attenuated H2O2-stimulated phosphorylation of c-Jun N-terminal kinase (JNK), while selective inhibition of JNK activity with SP600125 significantly attenuated H2O2-induced increase in SA-beta-gal activity. Results reveal that melatonin antagonizes premature senescence of HDPCs via JNK pathway. Thus, melatonin may have therapeutic potential to prevent stress-induced premature senescence, possibly correlated with development of dental pulp diseases, and to maintain oral health across the life span.
Porphyromonas gingivalis, one of the major periodontal pathogens, is implicated in the initiation and progression of periodontal disease. The initial stages of periodontal inflammation are accompanied by vascular hyperpermeability. In our present study, we report that the P. gingivalis lipopolysaccharide (LPS) increases the mRNA expression of interleukin-8 (IL-8), a major inducer of vascular permeability, in vascular endothelial cells. P. gingivalis LPS also stimulated the induction of IL-8 secretion in endothelial cells. The P. gingivalis LPS-induced expression of IL-8 was primarily modulated by nuclear factor-κB (NF-κB). P. gingivalis LPS significantly enhanced the vascular permeability both in vitro and in vivo, and a blockade of the IL-8 receptor decreased the P. gingivalis LPS-induced vascular permeability. Taken together, these results suggest that P. gingivalis LPS increases vascular permeability through the NF-κB-dependent production of IL-8 in vascular endothelial cells.
To provide a basis for studying the pharmacological actions of tetracaine HCl, we analyzed the membrane activities of this local anesthetic. The n-(9-anthroyloxy) stearic and palmitic acid (n-AS) probes (n = 2, 6, 9, 12 and 16) have been used previously to examine fluorescence polarization gradients. These probes can report the environment at a graded series of depths from the surface to the center of the membrane bilayer structure. In a dosedependent manner, tetracaine HCl decreased the anisotropies of 6-AS, 9-AS, 12-AS and 16-AP in the hydrocarbon interior of synaptosomal plasma membrane vesicles isolated from bovine cerebral cortex (SPMV), and liposomes derived from total lipids (SPMVTL) and phospholipids (SPMVPL) extracted from the SPMV. However, this compound increased the anisotropy of 2-AS at the membrane interface. The magnitude of the membrane rotational mobility reflects the carbon atom numbers of the phospholipids comprising SPMV, SPMVTL and SPMVPL and was in the order of the 16, 12, 9, 6, and 2 positions of the aliphatic chains. The sensitivity of the effects of tetracaine HCl on the rotational mobility of the hydrocarbon interior or surface region was dependent on the carbon atom numbers in the descending order 16-AP, 12-AS, 9-AS, 6-AS and 2-AS and on whether neuronal or model membranes were involved in the descending order SPMV, SPMVPL and SPMVTL.