RESUMO
OBJECTIVE: To explore the delayed neuroprotection induced by paeoniflorin (PF), the principal component of Paeoniae radix prescribed in Chinese medicine, and its underlying mechanisms in rats subjected to vascular dementia (VD). METHODS: A rat model of VD was induced by bilateral common carotid arteries occlusion (BCCAO). Low-dose or high-dose PF (20 or 40 mg/kg once per day) was administrated for 28 days after VD. The behavioral analysis of rat was measured by water morris. Regional cerebral blood volume (rCBV), regional cerebral blood flflow (rCBF) and mean transit time (MTT) were measured in the bilateral hippocampus by perfusion-weighted imaging (PWI). The levels of interleukin-1ß (IL-1ß), interleukin-6 (IL-6), and tumor necrosis factor alpha (TNF-α) were measured by commercially available enzyme-linked immunosorbent assay kits. Protein levels were evaluated by western blot analysis. mRNA levels were evaluated by real time-polymerase chain reaction. Western blotting was used to estimate p65 translocation. RESULTS: The behavioral analysis showed that PF could decrease the escape latency time (P<0.05), and increase the residence time of the original platform quadrant and the across platform frequency in water maze in VD rats (P<0.05). Likewise, PF remarkably promoted the rCBV (P<0.05), rCBF and decreased per minute MTT (P<0.05) in hippocampus of VD rats. Furthermore, PF decreased the release of IL-1ß, IL-6 and TNF-α as well as inhibited the mRNA expression of IL-1ß, IL-6 and TNF-α in the hippocampus of VD rats (P<0.05 or P<0.01). PF also could decrease the protein expressions of inducible nitric oxide synthase and cyclooxygenase-2 in the hippocampus of VD rats (P<0.05 or P<0.01). In addition, PF signifificantly inhibited the nuclear factor κB (NF-κB) pathway in the hippocampus of VD rats. CONCLUSIONS: PF signifificantly attenuates cognitive impairment, improves hippocampus perfusion and inhibits inflflammatory response in VD rats. In addition, the anti-inflflammatory effects of PF might be due to inhibiting the NF-κB pathway. PF may be a potential clinical application in improving VD.
Assuntos
Circulação Cerebrovascular , Demência Vascular/tratamento farmacológico , Glucosídeos/uso terapêutico , Hipocampo/irrigação sanguínea , Hipocampo/patologia , Mediadores da Inflamação/metabolismo , Monoterpenos/uso terapêutico , Animais , Circulação Cerebrovascular/efeitos dos fármacos , Disfunção Cognitiva/complicações , Disfunção Cognitiva/tratamento farmacológico , Disfunção Cognitiva/fisiopatologia , Ciclo-Oxigenase 2/metabolismo , Demência Vascular/enzimologia , Demência Vascular/patologia , Regulação para Baixo/efeitos dos fármacos , Glucosídeos/química , Glucosídeos/farmacologia , Hipocampo/efeitos dos fármacos , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , Transtornos da Memória/complicações , Transtornos da Memória/tratamento farmacológico , Transtornos da Memória/fisiopatologia , Monoterpenos/química , Monoterpenos/farmacologia , Óxido Nítrico Sintase Tipo II/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos Sprague-Dawley , Fator de Transcrição RelA/metabolismoRESUMO
PURPOSE: We assessed whether tetramethylpyrazine (TMP), an active ingredient of Ligusticum wallichii Franchat, attenuates atherosclerosis (AS) development in rabbits and protects endothelial cells injured by ox-LDL. METHODS: In vivo, rabbits subjected to atherosclerosis were treated with TMP (75 and 150 mg/kg) by oral gavage for 12 weeks. In vitro, rat aortic endothelial cells (RAECs) were stimulated by ox-LDL. RESULTS: TMP treatment with 75 and 150 mg/kg significantly reduced the relative atherosclerosis area ratio in the aorta (0.41 ± 0.042, 0.27 ± 0.047 vs. 0.66 ± 0.058 in AS), the ratio of intimal/medial thickness (0.54 ± 0.09, 0.39 ± 0.07 vs. 1.1 ± 0.3 in AS) and the number of monocytes in intimal (10.1 ± 2.8, 8.2 ± 2.0 vs. 14.1 ± 4.9 counts/mm(2) in AS). TMP also decreased levels of TC (15 ± 4.2 to 6.1 ± 1.2 mmol/L), TG (1.8 ± 0.3 to 1.08 ± 0.24 mmol/L), LDL-C (20.1 ± 4.3 to 10.2 ± 1.6 mmol/L) and increased HDL-C levels (0.40 ± 0.08 to 0.85 ± 0.17 mmol/L) in atherosclerosis rabbit plasma. TMP decreased the MCP-1 (187.3 ± 38.4 to 86.1 ± 17.2 pg/ml) and ICAM-1 (350.6 ± 43.7 to 260.6 ± 46.1 pg/ml) levels in plasma and inhibited LOX-1 expression in the rabbit aortas. Moreover, our in vitro study revealed that TMP suppressed monocyte adhesion to RAECs, inhibited RAEC migration, and down-regulated MCP-1 and ICAM-1 expression in ox-LDL-injured RAECs. Likewise, TMP inhibited LOX-1 and 5-LOX expression, and prevented nuclear accumulation of RelA/p65 and IκB degradation in ox-LDL-injured RAECs. Furthermore, TMP suppressed ox-LDL-induced activations of p-ERK, p-p38, and p-JNK MAPK. CONCLUSION: TMP produces a tangible protection in atherosclerosis and endothelial cells. TMP might be a potential protective agent for atherosclerosis.