Catalpol improves impaired neurovascular unit in ischemic stroke rats via enhancing VEGF-PI3K/AKT and VEGF-MEK1/2/ERK1/2 signaling.

Neurovascular unit (NVU) is organized multi-cellular and multi-component networks that are essential for brain health and brain homeostasis maintaining. Neurovascular unit dysfunction is the central pathogenesis process of ischemic stroke. Thus integrated protection of NVU holds great therapeutic potential for ischemic stroke. Catalpol, classified into the iridoid monosaccharide glycoside, is the main active ingredient of the radix from traditional Chinese medicine, Rehmannia glutinosa Libosch, that exhibits protective effects in several brain-related diseases. In the present study, we investigated whether catalpol exerted protective effects for NVU in ischemic stroke and the underlying mechanisms. MCAO rats were administered catalpol (2.5, 5.0, 10.0 mg·kg-1·d-1, i.v.) for 14 days. We showed that catalpol treatment dose-dependently reduced the infarction volume and significantly attenuated neurological deficits score in MCAO rats. Furthermore, catalpol treatment significantly ameliorated impaired NVU in ischemic region by protecting vessel-neuron-astrocyte structures and morphology, and promoting angiogenesis and neurogenesis to replenish lost vessels and neurons. Moreover, catalpol treatment significantly increased the expression of vascular endothelial growth factor (VEGF) through up-regulating PI3K/AKT signaling, followed by increasing FAK and Paxillin and activating PI3K/AKT and MEK1/2/ERK1/2 pathways. The protective mechanisms of catalpol were confirmed in an in vitro three-dimensional NVU model subjected to oxygen-glucose deprivation. In conclusion, catalpol protects NVU in ischemic region via activation of PI3K/AKT signaling and increased VEGF production; VEGF further enhances PI3K/AKT and MEK1/2/ERK1/2 signaling, which may trigger a partly feed-forward loop to protect NVU from ischemic stroke.

[Analysis of blood components of Yougui Yin in normal rats and rats with kidney deficiency caused by adenine based on UPLC-MS technology].

Based on the serum medicinal method, this study aims to investigate the migrating components of Yougui Yin in the blood after intragastric administration, and to provide reference for the basic research of its pharmacodynamics. The kidney deficiency rat model was replicated by adenine method. Normal rats and model rats were administered orally for a single gavage of Yougui Yin. The components in blood were rapidly analyzed and identified by ultra-high performance liquid chromatography/quadrupole time-of-flight mass spectrometry(UPLC-Q-TOF-MS) and multiple reaction monitoring(MRM), and the migrating components in blood of Yougui Yin were explored by multivariate statistical analysis. The results showed that there were 42 characteristic peaks in the plasma of normal rats by UPLC-Q-TOF-MS technology and 13 chemical components were identified, including 6 alkaloids, 2 flavonoids, 2 triterpenoid saponins, 1 iridoid, 1 phenylpropanoid and 1 monoterpenoid. There were 22 characteristic peaks in the plasma of kidney-deficiency rats, and 12 chemical components were identified, including 2 iridoids, 6 alkaloids, 2 flavonoids, 1 monoterpenoid and 1 triterpenoid saponin. Verbascoside, isoacteoside, acteoside, pinoresinoldiglucoside, loganin and morroniside were identified by MRM both in the plasma of normal rats and kidney-deficiency rats. Compared with 85 monomer components in Yougui Yin, 17 common prototype components were found by UPLC-MS in the plasma of normal rats and kidney deficiency rats, including verbascoside, isoacteoside, acteoside, rehmapicrogenin derived from Rehmanniae Radix Praeparata, pinoresinol diglucoside and geniposidic acid from Eucommiea Cortex, loganin and morroniside derived from Corni Fructus, mesaconine, benzoylmesaconine, benzoylaconitine, benzoylhypacoitine, mesaconitine, aconitine derived from Aconiti Lateralis Radix Praeparata, liquiritin, isoliquiritin and glycyrrhizic acid derived from Glycyrrhizae Radix et Rhizoma. Thirty-one metabolites of medicinal ingredients not found in the plasma of adenine-induced kidney deficiency rats were also detected in the plasma of normal rats. Twelve metabolites of medicinal materials not found in the plasma of normal rats were detected in the plasma of kidney deficiency rats. The results of the study provide reference for explaining the material basis and mechanism of Yougui Yin in the treatment of kidney deficiency.