[Efficacy of compound Dendrobium on PI3K/AKT/eNOS signaling pathway in hypertensive rats induced by "dietary disorders"].

To observe the efficacy of compound Dendrobium on Sprague Dawley rats (SD) hypertension model induced by "dietary disorders" and its relevant mechanism, totally 50 SD rats were fed with high-sugar, high-fat diet and alcohol for four weeks. According to the blood pressure after modeling, the rats were divided into model group, valsartan group (8 mg·kg⁻¹), low, medium and high-dose Dendrobium candidum compound groups (1.65, 3.30, 5.00 g·kg⁻¹), with 10 rats in each group, and the other 10 SD rats were also taken as the normal group. After four weeks of treatment, blood pressure was measured. Orbital blood was collected for the determination of serum cholesterol (TC), triglycerides (TG), low-density lipoprotein cholesterol (LDL-c), high-density lipoprotein cholesterol (HDL), calculation of atherosclerosis index (AI). Nitric acid reductase method was used to detect serum nitric oxide (NO); the levels of serum endothelin-1 (ET-1) and intercellular adhesion molecule-1 (ICAM-1) were measured by ELISA. The rats were put to death after the last administration, and the protein expressions of PI3K/AKT/eNOS in thoracic aorta of rats in each group were detected by Western blot. The aorta was separated and stained with hematoxylin-eosin (HE) to observe the changes in the endothelium and blood vessels in the thoracic aorta. Masson staining was used to observe the formation of aortic collagen. The expressions of nitric oxide synthase (eNOS) and ICAM-1 in aortic endothelial cells were observed by immunohistochemistry. In contrast, the results show D. candidum compound can significantly reduce the blood pressure in hypertensive rats, increase HDL-c, and reduce AI, while increasing serum NO content, decreasing ET-1 and ICAM-1 levels and promoting PI3K/AKT/NOS protein expressions. The lesion degree of the D. candidum compound group was reduced, and the collagen deposition was significantly reduced. Meanwhile, D. candidum compound can significantly increase the expression of eNOS, and reduce the formation of ICAM-1.Therefore, D. candidum compound has an obvious antihypertensive effect on hypertensive rats, which may be related to the increase in PI3K/AKT/eNOS signaling pathways and NO generation, the inhibition of the secretion of ICAM-1 and ET-1, the protection of the vascular endothelium and the improvement of aortic disease.

Beneficial Effects of Paeoniflorin Enriched Extract on Blood Pressure Variability and Target Organ Damage in Spontaneously Hypertensive Rats.

Blood pressure variability (BPV) is associated with the development and progression of severe target organ damage (TOD). This study aims to evaluate the protective effect of paeoniflorin enriched extract from Radix Paeoniae Alba (PG) on BPV and TOD in spontaneously hypertensive rats (SHR). All SHR were orally treated with distilled water, metoprolol (MP, 20 mg/kg), and PG (PG-H, 90 mg/kg or PG-L, 30 mg/kg) for a single time or daily for 7 weeks. The 24-hour dynamic blood pressure was monitored and then calculated BPV including long- and short-term systolic blood pressure variability (SBPV), diastolic blood pressure variability (DBPV), mean blood pressure variability (MBPV), and heart rate variability (HRV) as well as the 24-hour-SBP, 24-hour-DBP, and 24-hour-MBP. The protective effects of PG on TOD were observed by histopathologic and biochemical detection. The results indicated that long- and short-term SBPV, DBPV, MBPV, and HRV as well as 24-hour-SBP, 24-hour-DBP, and 24-hour-MBP showed no significant changes after single-dose administration of PG and significantly decreased after administration with PG for 7 weeks. PG could also markedly improve the damage of aorta, heart, kidney, and brain. This study suggested that PG could notably reduce BPV, stabilize blood pressure, and mitigate TOD in SHR.

[Studies on the saliva adsorption and the salivary film property on the hydroxyapatite surface].

OBJECTIVE: To evaluate the thickness and viscoelasticity of whole saliva (WS), parotid saliva (PS) and submandibular/sublingual gland saliva (SMSLS) film adsorption on the hydroxyapatite (HA) surface. METHODS: Ultra-thin layer of HA nanocrystals was coated on the dissipation TiO(2) sensor of gold quartz crystal microbalance using electrophoretic deposition technique. The thickness of the HA layer was measured by the ellipsometer, and element analysis was conducted using X-ray photoelectron spectroscopy. Atomic force microscopy and scanning electron microscope were used to observe its morphology. The in-situ adsorption thickness, the shear elastic modulus and the shear viscosity of salivary layers (WS, PS and SMSLS) on HA surfaces were investigated. The statistical data were analysed by an one-way ANOVA analysis followed by a SNK-q test. RESULTS: The results show that the HA layer was a plate-like morphology with 1.53 ± 0.12 in Ca/P molar ratio, (19.1 ± 0.9) nm in the thickness and (6.5 ± 1.6) nm in the roughness. The thickness of salivary film was SMSLS [(21.84 ± 1.25) nm] > WS[(17.91 ± 1.35) nm] > PS [(14.30 ± 1.03 nm) (P < 0.05). The shear elastic modulus of salivary film was PS [(0.61 ± 0.01) MPa] > SMSLS [(0.31 ± 0.09) MPa] and WS [(0.25 ± 0.03) MPa] (P < 0.05). The trend of the shear viscosity was opposite to one of thickness. CONCLUSIONS: The characteristics of saliva adsorption on HA surface suggest that the thicker, softer and more hydrated properties for the SMSLS and WS films are likely to afford a stronger lubrication to protect oral surfaces from wear and dehydration. The viscoelasticity of the PS film is probably related to the retention covering the oral cavity.

The interactions of epigallocatechin-3-gallate with human whole saliva and parotid saliva.

OBJECTIVE: The aim of the present study was to assess the null hypothesis that the astringency and loss of lubrication in the oral cavity are not related to the properties of the epigallocatechin-3-gallate (EGCG) adlayer, the affinity and the entropy-drive of EGCG binding to saliva. METHODS: The mass, thickness, and viscoelasticity of the EGCG adlayer and the temperature dependence of EGCG adsorption onto saliva surfaces were determined by quartz crystal microbalance with dissipation (QCM-D). The affinities of EGCG to human whole saliva (WS) and to parotid saliva (PS) were carried out by QCM-D monitoring and fluorescence quenching. RESULTS: The stiffer and more compact EGCG adlayers were formed on saliva surfaces at various concentrations of EGCG. The affinity for EGCG binding to WS was higher than that to PS. The precipitation of EGCG/saliva was temperature-dependent. The driving force of EGCG binding to saliva is dominated by the hydrogen bond, the hydrophobic reaction, and the entropy-drive, which were confirmed by the FTIR spectra and the measurement of temperature- dependence, respectively. CONCLUSION: The viscoelasticity of the EGCG adlayer, the affinity of EGCG to saliva, and the priority of EGCG binding to hydrophobic proteins on the mucosa may account for the oral astringency and loss of lubrication.