Effects of L-tetrahydropalmatine on neuron apoptosis during acute cerebral ischemia-reperfusion of rats

Advances in phytochemical and modern pharmacological research of Rhizoma Corydalis

ABSRACTContext: Rhizoma Corydalis (RC) is the dried tubers of Corydalis yanhusuo (Y. H. Chou and Chun C. Hsu) W. T. Wang ex Z. Y. Su and C. Y. Wu (Papaveraceae). Traditionally, RC is used to alleviate pain such as headache, abdominal pain, and epigastric pain. Modern medicine shows that it has analgesic, anti-arrhythmia, and other effects.Objective: We provided an overview of the phytochemical and pharmacological properties of RC as a foundation for its clinical application and further research and development of new drugs.Methods: We collected data of various phytochemical and pharmacological effects of RC from 1982 to 2019. To correlate with existing scientific evidence, we used Google Scholar and the journal databases Scopus, PubMed, and CNKI. 'Rhizoma Corydalis', 'phytochemistry', and 'pharmacological effects' were used as key words.Results: Currently, more than 100 chemical components have been isolated and identified from RC, among which alkaloid is the pimary active component of RC. Based on prior research, RC has antinociceptive, sedative, anti-epileptic, antidepressive and anti-anxiety, acetylcholinesterase inhibitory effect, drug abstinence, anti-arrhythmic, antimyocardial infarction, dilated coronary artery, cerebral ischaemia reperfusion (I/R) injury protection, antihypertensive, antithrombotic, antigastrointestinal ulcer, liver protection, antimicrobial, anti-inflammation, antiviral, and anticancer effects.Conclusions: RC is reported to be effective in treating a variety of diseases. Current pharmacological studies on RC mainly focus on the nervous, circulatory, digestive, and endocrine systems, as well as drug withdrawal. Although experimental data support the beneficial effects of this drug, its physiological activity remains a concern. Nonetheless, this review provides a foundation for future research.

Protective Effect of Mitogen- and Stress-Activated Protein Kinase on the Rats with Focal Ischemia-Reperfusion Injury

Mitogen- and stress-activated protein kinase (MSK) is a recently identified nuclear cAMP-regulated enhancer B (CREB) and histone H3 kinase that responds to both mitogen- and stress-activated protein kinases. This study was designed to investigate the protective effect of MSK on the rats with focal ischemia-reperfusion injury. The rat model was established by inserting thread into the middle cerebral artery. The protein expression was measured by immunoblotting. The localization of MSK was measured by immunofluorescence assay. Highly-differentiated pheochromocytoma 12 (PC12) is used as a sympathetic neuron-like cell line and treated with glutamate to induce neurotoxicity. MSK was knocked down and overexpressed by siRNA and MSK over-expressing vector, respectively. The cell viability was measured by cell counting kit (CCK-8) assay. The coronal sections were isolated and stained with 2, 3, 5-triphenyltetrazolium chloride (TTC) to determine infarct volume. Finally, astrocytes were separated from cerebral cortexes of normal rats to analyze the effects of MSK on inflammatory response. In the rats with focal ischemia-reperfusion injury, the expression of MSK was reduced, reaching the lowest level at 3 d after ischemia-reperfusion, and then recovered gradually. MSK was found mainly localized in neurons and astrocytes. The expression levels of caspase-3, caspase-8, caspase-9, and INOS showed the opposite trend with respect to MSK. Further analysis showed that overexpression of MSK exerted a protective effect on glutamate-induced neurotoxicity through inhibiting apoptosis of PC12 cells, as well as decreased the infarct size in rat with focal ischemia-reperfusion injury. On the contrary, knockdown of MSK showed opposite results. Finally, MSK suppressed LPS-induced inflammatory response by decreasing the expression of inducible nitric oxide synthase (INOS) and increasing the expression of interleukin-10 (IL-10) in astrocytes from cerebral cortexes of normal rats. In conclusion, MSK exerted a protective effect on rat with focal ischemia-reperfusion injury through its anti-apoptotic effect on neurons and anti-inflammatory effect on astrocytes.

Levo-tetrahydropalmatine attenuates mouse blood-brain barrier injury induced by focal cerebral ischemia and reperfusion: Involvement of Src kinase

The restoration of blood flow following thrombolytic therapy causes ischemia and reperfusion (I/R) injury leading to blood-brain barrier (BBB) disruption and subsequent brain edema in patients of ischemic stroke. Levo-tetrahydropalmatine (l-THP) occurs in Corydalis genus and some other plants. However, whether l-THP exerts protective role on BBB disrpution following cerebral I/R remains unclear. Male C57BL/6N mice (23 to 28 g) were subjected to 90 min middle cerebral artery occlusion, followed by reperfusion for 24 h. l-THP (10, 20, 40 mg/kg) was administrated by gavage 60 min before ischemia. We found I/R evoked Evans blue extravasation, albumin leakage, brain water content increase, cerebral blood flow decrease, cerebral infarction and neurological deficits, all of which were attenuated by l-THP treatment. Meanwhile, l-THP inhibited tight junction (TJ) proteins down-expression, Src kinase phosphorylation, matrix metalloproteinases-2/9 (MMP-2/9) and caveolin-1 activation. In addition, surface plasmon resonance revealed binding of l-THP to Src kinase with high affinity. Then we found Src kinase inhibitor PP2 could attenuate Evans blue dye extravasation and inhibit the caveolin-1, MMP-9 activation, occludin down-expression after I/R, respectively. In conclusion, l-THP attenuated BBB injury and brain edema, which were correlated with inhibiting the Src kinase phosphorylation.

L-tetrahydropalamatine inhibits tumor necrosis factor-α-induced monocyte-endothelial cell adhesion through downregulation of intercellular adhesion molecule-1 and vascular cell adhesion molecule-1 involving suppression of nuclear factor-κ B signaling pathway

OBJECTIVE

To investigate whether I-tetrahydropalmatine (I-THP), an alkaloid mainly present in Corydalis family, could ameliorate early vascular inflammatory responses in atherosclerotic processes.

METHODS

Fluorescently labeled monocytes were co-incubated with human umbilical vein endothelial cells (HUVECs), which were pretreated with I-THP and then simulated with tumor necrosis factor (TNF)-α in absence of I-THP to determine if I-THP could reduce thecytokine-induced adhesion of monocytes to HUVECs. Then I-THP were further studied the underlying mechanisms through observing the transcriptional and translational level of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) and the nuclear translocation of nuclear factor (NF)-κ B in HUVECs.

RESULTS

L-THP could block TNF-α-induced adhesion of monocytes to HUVECs and could significantly inhibited the expression of ICAM-1 and VCAM-1 on cell surface by 31% and 36% at 30 μ mol/L. L-THP pretreatment could also markedly reduce transcriptional and translational level of VCAM-1 as well as mildly reduce the total protein and mRNA expression levels of ICAM-1. Furthermore, I-THP attenuated TNF-α-stimulated NF-κ B nuclear translocation.

CONCLUSION

These results provide evidences supporting that I-THP could be a promising compound in the prevention and treatment of the early vascular inflammatory reaction in atherosclerosis by inhibiting monocyte adhesion to vascular endothelial cell through downregulating ICAM-1 and VCAM-1 in vascular endothelial cell based on suppressing NF-κ B.

l-Tetrahydropalmatine, an active component of Corydalis yanhusuo W.T. Wang, protects against myocardial ischaemia-reperfusion injury in rats

l-Tetrahydropalmatine (l-THP) is an active ingredients of Corydalis yanhusuo W.T. Wang, which protects against acute global cerebral ischaemia-reperfusion injury. In this study, we show that l-THP is cardioprotective in myocardial ischaemia-reperfusion injury and examined the mechanism. Rats were treated with l-THP (0, 10, 20, 40 mg/kg b.w.) for 20 min before occlusion of the left anterior descending coronary artery and subjected to myocardial ischaemia-reperfusion (30 min/6 h). Compared with vehicle-treated animals, the infarct area/risk area (IA/RA) of l-THP (20, 40 mg/kg b.w.) treated rats was reduced, whilst l-THP (10 mg/kg b.w.) had no significant effect. Cardiac function was improved in l-THP-treated rats whilst plasma creatine kinase activity declined. Following treatment with l-THP (20 mg/kg b.w.), subunit of phosphatidylinositol 3-kinase p85, serine⁴⁷³ phosphorylation of Akt and serine¹¹⁷⁷ phosphorylation of endothelial NO synthase (eNOS) increased in myocardium, whilst expression of inducible NO synthase (iNOS) decreased. However, the expression of HIF-1α and VEGF were increased in I_{30 min}R_{6 h}, but decreased to normal level in I_{30 min}R_{24 h}, while treatment with l-THP (20 mg/kg b.w.) enhanced the levels of these two genes in I_{30 min}R_{24 h}. Production of NO in myocardium and plasma, activity of myeloperoxidase (MPO) in plasma and the expression of tumour necrosis factor-α (TNF-α) in myocardium were decreased by l-THP. TUNEL assay revealed that l-THP (20 mg/kg b.w.) reduced apoptosis in myocardium. Thus, we show that l-THP activates the PI3K/Akt/eNOS/NO pathway and increases expression of HIF-1α and VEGF, whilst depressing iNOS-derived NO production in myocardium. This effect may decrease the accumulation of inflammatory factors, including TNF-α and MPO, and lessen the extent of apoptosis, therefore contributing to the cardioprotective effects of l-THP in myocardial ischaemia-reperfusion injury.

Effects of electroacupuncture on hippocampal and cortical apoptosis in a mouse model of cerebral ischemia-reperfusion injury

OBJECTIVE

To observe the effects of electroacupuncture on hippocampal and cortical apoptosis in a mouse model of cerebral ischemia-reperfusion injury.

METHODS

Mouse models established by repeated cerebral ischemia-reperfusion, followed by electroacupuncture at Shenshu, Geshu, and Baihui points. The control group mice were intragastrically administered Hydergine. On day 1 and 7 post-treatment, hippocampal and cortical apoptosis was detected by terminal-deoxynucleotidyl transferase mediated dUTP nick-end labeling (TUNEL), and apoptosis images in the hippocampal CA1 zone and cortical area were analyzed.

RESULTS

In the model group, apoptotic cells were detected one day after treatment and some cellular fibers were disarrayed. By day 7 post-treatment, there was an increase in the number of apoptotic cells in the hippocampal CA1 region. In addition, there were apoptotic cells in the cortical area, the cortical layers were thinner with localized neuronal loss and sieve-like lymphocyte infiltration, as well as glial cell proliferation and visible infarct lesions. However, in the Hydergine and electroacupuncture groups, there was a small number of apoptotic cells. At 7 days post-treatment in the model group, field number, numerical density on area, and surface density were increased. However, in the Hydergine and electroacupuncture groups these parameters were decreased (P < 0.01), with a significant difference between the two treatment groups (P < 0.01).

CONCLUSION

Electroacupuncture treatment inhibited apoptosis and provided neuroprotection.

Beneficial effects of the extract from Corydalis yanhusuo in rats with heart failure following myocardial infarction

As indicated in ancient Chinese medical books, Corydalis yanhusuo has therapeutic effects on cardiovascular diseases. The analgesic effect of this plant has been fully elucidated, and I-tetrahydropalmatine has been shown to be the main active principle. The aim of this investigation was to evaluate its protective effects in a rat heart failure model. Rats were subjected to coronary artery ligation, and orally administered with ethanolic extract of Corydalis yanhusuo 50, 100, or 200 mg kg−1 daily, from the 7th day after surgery. We measured cardiac function, plasma atrial natriuretic peptide (ANP), relative heart and lung weights, infarct size and ventricular dilatation after treatment for 8 weeks. Administration with Corydalis yanhusuo led to a significant reduction in infarct size and improvement in cardiac function as demonstrated by lower left ventricular end diastolic pressure (LVEDP) and elevated ± dp/dtmax. We also found that Corydalis yanhusuo significantly reduced left ventricular (LV)/body weight ratio, lung/body weight ratio and significantly inhibited neurohormonal activation. Taken together, this study indicated that Corydalis yanhusuo exerted salutary effects on heart failure induced by myocardial infarction in rats.