[Inhibition of Paeoniflorin on TNF-α-induced TNF-α Receptor Type I /Nuclear Factor-κB Signal Transduction in Endothelial Cells].

OBJECTIVE: To study the inhibitory effect of paeoniflorin (PAE) on TNF-α-induced TNF receptor type I (TNFR1)-mediated signaling pathway in mouse renal arterial endothelial cells (AECs) and to explore its underlying molecular mechanisms. METHODS: Mouse AECs were cultured in vitro and then they were treated by different concentrations PAE or TNF-α for various time periods. Expression levels of intercellular cell adhesion molecule-1 (ICAM-1) were detected in the normal group (cultured by serum-free culture media), the TNF-α group (cultured by 2-h serum-free culture media plus 6-h TNF-α 30 ng/mL), the low dose PAE group (cultured by 2-h PAE 0.8 µmo/L plus 6-h TNF-α 30 ng/mL), the middle dose PAE group (cultured by 2-h PAE 8 µmol/L plus 6-h TNF-α 30 ng/mL), the high dose PAE group (cultured by 2-h PAE 80 µmol/L plus 6-h TNF-α 30 ng/mL) with Western blot analysis. Nuclear translocation of transcription factor NF-κB (NE-κB) was detected in the normal group (cultured by serum-free culture media), the TNF-α group (cultured by 2-h serum-free culture media plus 45-mm TNF-α 30 ng/mL), and the high dose PAE group (cultured by 2-h PAE 80 µmol/L plus 45-min TNF-α 30 ng/mL) by immunofluorescent staining. Expression levels of the phosphorylation of extracellular signal-regulated (protein) kinase (ph-ERK) and p38 (ph- p38) were detected in the normal group (cultured by serum-free culture media) and the high dose PAE group (2-h PAE 80 µmol/L culture) by Western blot. NF-κB inhibitor-α (IκBα) protein expressions were detected in the normal group (cultured by serum-free culture media), the TNF-α group (cultured by 2-h serum-free culture media plus 30-min TNF-α 30 ng/mL), the high dose PAE group (cultured by 2-h PAE 80 µmol/L plus 30-min TNF-α 30 ng/mL), the p38 inhibitor group (SB group, pretreatment with SB238025 25 µmol/L for 30 min, then treated by PAE 80 µmol/L for 2 h, and finally treated by TNF-α 30 ng/mL for 30 min), the ERK inhibitor group (PD group, treated by PD98059 50 µmol/L for 30 min, then treated by PAE 80 µmol/L for 2 h, and finally treated by TNF-α 30 ng/mL for 30 min) by Western blot. RESULTS: Compared with the normal group, ICAM-1 protein expression levels obviously increased (P < 0.01). Compared with the TNFα group, ICAM-1 protein expression levels were obviously inhibited in the high dose PAE group (P < 0.05). Protein expression levels of ph-p38 and ph-ERK were obviously higher in the hIgh dose PAE group (P < 0.05). Compared with the normal group, IκBα protein expression levels obviously decreased in the TNF-α group (P < 0.01). Compared with the TNFα group, TNF-α-induced IκBα degradation could be significantly inhibited in the high dose PAE group (P < 0.01); the inhibition of PAE on IκBα degradation could be significantly inhibited in the SB group (P < 0.05). NF-κB/p65 signal was mainly located in cytoplasm in the normal group. NF-κB/p65 was translocated from cytoplasm to nucleus after stimulated by 45 min TNF-α in the TNF-α group, while it could be significantly inhibited in the high dose PAE group. CONCLUSIONS: PAE inhibited TNF-α-induced expression of lCAM-1. Its action might be associated with inhibiting TNFR1/NF-κB signaling pathway. p38 participated and mediated these actions.

[Pharmacokinetic effect of Sappan Lignum on hydroxysafflor yellow A in Carthami Flos].

OBJECTIVE: To investigate the pharmacokinetic effect of Sappan Lignum on hydroxysafflor yellow A (HSYA) in Carthami Flos. METHOD: Concentration of HSYA in rat plasma was detected by RP-HPLC after rats were orally administered with extracts of Carthami Flos or Carthami Flos combined with Sappan Lignum. Pharmacokinetic parameters were calculated by DAS 2.0 pharmacokinetic software. RESULT: In vivo pharmacokinetic models of HSYA were two-compartment open models in both of the Carthami Flos group and the Carthami Flos combined with Sappan Lignum group. After compatibility, HSYA showed a significant lower in apparent volumes of distribution of t(1/2Ka), t(1/2alpha) and V1/F, with slight advance in T(max). CONCLUSION: Sappan Lignum can accelerate absorption, distribution and metabolic process of HSYA in vivo and reduce its accumulation in vivo.

A comparative study on inhibition of total astragalus saponins and astragaloside IV on TNFR1-mediated signaling pathways in arterial endothelial cells.

BACKGROUND: Both total astragalus saponins (AST) and it's main component astragaloside IV (ASIV) have been used in China as cardiovascular protective medicines. However, the anti-inflammatory activities that are beneficial for cardiovascular health have never been compared directly and the molecular mechanisms remain unresolved. This study was conducted to compare the inhibitory effects of these drugs on TNFα-induced cell responses, related signaling pathways, and the underlying mechanisms in mouse arterial endothelial cells. METHODOLOGY/PRINCIPAL FINDINGS: Real-time qRT-PCR was performed to determine the expression of cell adhesion molecule (CAM) genes. Immunofluorescent staining was used to detect the nuclear translocation of transcription factor NF-κB-p65. Western Blot analysis was used to identify TNFα-induced NF-κB-p65 phosphorylation, IκBα degradation, and caspase-3 cleavage. Cell surface proteins were isolated and TNFα receptor-1(TNFR1) expression was determined. The results suggest that both AST and ASIV attenuate TNFα-induced up-regulation of CAMs mRNA and upstream nuclear translocation and phosphorylation of NF-κB-p65. However, TNFR1-mediated IκBα degradation, cleavage of caspase-3 and apoptosis were inhibited only by AST. These differences in the actions of AST and ASIV could be explained by the presence of other components in AST, such as ASII and ASIII, which also had an inhibitory effect on TNFR1-induced IκBα degradation. Moreover, AST, but not ASIV, was able to reduce TNFR1 protein level on the cell surface. Furthermore, mechanistic investigation demonstrated that TNFR1-mediated IκBα degradation was reversed by the use of TAPI-0, an inhibitor of TNFα converting enzyme (TACE), suggesting the involvement of TACE in the modulation of surface TNFR1 level by AST. CONCLUSION: ASIV was not a better inhibitor than AST, at least on the inhibition of TNFα-induced inflammatory responses and TNFR1-mediated signaling pathways in AECs. The inhibitory effect of AST was caused by the reduction of cell surface TNFR1 level, and TACE could be involved in this action.