Catalpol modulates the expressions of Bcl-2 and Bax and attenuates apoptosis in gerbils after ischemic injury

Protective effects of catalpol on cardio-cerebrovascular diseases: A comprehensive review

Catalpol, an iridoid glucoside isolated from Rehmannia glutinosa, has gained attention due to its potential use in treating cardio-cerebrovascular diseases (CVDs). This extensive review delves into recent studies on catalpol's protective properties in relation to various CVDs, such as atherosclerosis, myocardial ischemia, infarction, cardiac hypertrophy, and heart failure. The review also explores the compound's anti-oxidant, anti-inflammatory, and anti-apoptotic characteristics, emphasizing the role of vital signaling pathways, including PGC-1α/TERT, PI3K/Akt, AMPK, Nrf2/HO-1, estrogen receptor (ER), Nox4/NF-κB, and GRP78/PERK. The article discusses emerging findings on catalpol's ability to alleviate diabetic cardiovascular complications, thrombosis, and other cardiovascular-related conditions. Although clinical studies specifically addressing catalpol's impact on CVDs are scarce, the compound's established safety and well-tolerated nature suggest that it could be a valuable treatment alternative for CVD patients. Further investigation into catalpol and related iridoid derivatives may unveil new opportunities for devising natural and efficacious CVD therapies.

Mechanism of action of Daqinjiao decoction in treating cerebral small vessel disease explored using network pharmacology and molecular docking technology

BACKGROUND AND PURPOSE

Cerebral small vessel disease (CSVD) is a clinically commonly-seen slow-progressing cerebral vascular disease. As a classic Chinese formula for the treatment of stroke, Daqinjiao Decoction (DQJD) is now used to treat CSVD with desirable effect. Since the mechanism of action is still unclear, this article will explore the therapeutic effect and mechanism of action of the formula using network pharmacology technology.

METHODS

The major chemical components and potential target genes of DQJD were screened by bioinformatics. The key targets in CSVD were identified based on network modules. Gene Ontology (GO) functional annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis were performed. Pharmacodynamics of the decoction was evaluated by establishing a rat model with bilateral common carotid artery occlusion in the brain. Molecular docking, Western blot analysis and quantitative real-time polymerase chain reaction (QRT-PCR) were performed to confirm the effectiveness of targets in related pathways.

RESULTS

Network pharmacology showed that 16 targets and 30 pathways were involved in the DQJD-targeted pathway network. Results revealed that DQJD might play a role by targeting the key targets including Caspse3 and P53 and regulating the P53 signaling pathway. Cognitive function and neuronal cell changes of rats were evaluated using Morris water maze, open field test and HE staining. It was indicated that DQJD could keep the nerve cells intact and neatly arranged. The decoction could improve the memory and learning ability of rats compared with the model group. It decreased the protein and mRNA expression levels of Caspse3 and P53 significantly (p<0.01).

CONCLUSION

The study shows that baicalein, quercetin and wogonin, the effective components of DQJD, may regulate multiple signaling pathways by targeting the targets like Caspse3 and P53 and treat CSVD by reducing the damage to brain nerve cells.

Catalpol Alleviates Isoflurane-Induced Hippocampal Learning and Memory Dysfunction and Neuropathological Changes in Aged Mice

INTRODUCTION

Isoflurane-associated perioperative neurocognitive disorders (PNDs) is a common complication that occurs commonly in elderly patients characterized by deterioration of hippocampus-dependent cognitive function. Mounting evidence has shown that hippocampal impairment and inflammatory processes are implicated in the pathogenesis of PNDs. Catalpol has been suggested to play a role in the modulation of neuroprotection and neurotransmission. Therefore, we surmised that catalpol may play a similar role during isoflurane-induced PNDs.

METHODS

In our current study, aged mice were exposed to isoflurane to develop a mouse model of PNDs and preconditioned with catalpol for 2 weeks before modeling. Three weeks after isoflurane exposure, behavioral, histological, biochemical, electrophysiological, and immunofluorescent assays were performed.

RESULTS

Our results showed that catalpol preadministration significantly alleviated cognitive impairment in the Morris water maze, novel object recognition, and Y-maze behavioral tests. Neuropathological analyses showed that catalpol preadministration reduced the loss of neurons and synapses; in line with this, it is revealed that hippocampal synaptic plasticity was restored. Mechanistically, catalpol preadministration suppressed the activation of microglia and decreased the expression of NLRP3 inflammasome.

CONCLUSION

Our results indicate that catalpol preadministration could effectively alleviate cognitive impairment and neuropathological damage in isoflurane-exposed aged mice with its neuroprotective effects via modulation of the NLRP3 inflammatory pathway. Furthermore, the NLRP3 inflammatory pathway was revealed to be involved in these effects.

Tinospora Cordifolia and Arabinogalactan in combination modulates benzo(a)pyrene-induced genotoxicity during lung carcinogenesis

The present study explored the effects of combination of Tinospora cordifolia and Arabinogalactan on surface membrane dynamics and programmed cell deaths in rat model of lung cancer. The rats were divided into different groups namely normal control, benzo(a)pyrene (BP) treated, BP + Tinospora cordifolia (TC)-treated, BP + Arabinogalactan (A)-treated and BP + TC + A-treated groups. Significant changes were observed in the membrane dynamics of rats treated with BP. The carcinogen treatment demonstrated a marked decrease in membrane microviscosity. Also, excimer/monomer ratio and fluidity parameters of BP treated rats showed significant rise. On the other hand, combination of Tinospora cordifolia and Arabinogalactan improvised surface membrane dynamics. Moreover, micronuclei formation along with protein expression of bcl-2 showed significant increase in the lungs of BP treated rats. The combined treatment of Tinospora cordifolia and Arabinogalactan moderated the micronuclei formation in BP treated rats. Also, the combined treatment regulated the protein expressions of bcl-2 in BP-treated rats. As a result, marked improvement was noticed in apoptosis of BP treated cells treated with combination treatment. This study concludes that the Tinospora cordifolia and Arabinogalactan in combination improve the surface membrane dynamics and apoptosis in BP-treated rats.

Neuroprotective Effect for Cerebral Ischemia by Natural Products: A Review

Natural products have a significant role in the prevention of disease and boosting of health in humans and animals. Stroke is a disease with high prevalence and incidence, the pathogenesis is a complex cascade reaction. In recent years, it’s reported that a vast number of natural products have demonstrated beneficial effects on stroke worldwide. Natural products have been discovered to modulate activities with multiple targets and signaling pathways to exert neuroprotection via direct or indirect effects on enzymes, such as kinases, regulatory receptors, and proteins. This review provides a comprehensive summary of the established pharmacological effects and multiple target mechanisms of natural products for cerebral ischemic injury in vitro and in vivo preclinical models, and their potential neuro-therapeutic applications. In addition, the biological activity of natural products is closely related to their structure, and the structure-activity relationship of most natural products in neuroprotection is lacking, which should be further explored in future. Overall, we stress on natural products for their role in neuroprotection, and this wide band of pharmacological or biological activities has made them suitable candidates for the treatment of stroke.

Catalpol ameliorates doxorubicin-induced inflammation and oxidative stress in H9C2 cells through PPAR-γ activation

Drug-induced cardiomyopathy is a severe disease that leads to refractory heart disease at late stages, with increasing detrimental effects. DOX-induced cell damage is primarily induced via cellular oxidative stress. The present study investigated the effects of catalpol on doxorubicin (DOX)-induced H9C2 cardiomyocyte inflammation and oxidative stress. The Cell Counting Kit-8 assay was performed to detect cell viability, and western blotting was performed to detect the expression of peroxisome proliferator-activated receptor (PPAR)-γ in H9C2 cells. The expression levels of tumor necrosis factor-α (TNF-α), interleukin (IL)-1β and IL-6 were measured using ELISAs. Furthermore, the oxidative stress kit was used to detect the levels of malondialdehyde, superoxide dismutase and glutathione peroxidase. A reactive oxygen species (ROS) kit and DCF-DA staining were used to detect ROS levels. The results indicated that DOX treatment inhibited H9C2 cell expression of PPAR-γ and decreased H9C2 cell viability. Various concentrations of catalpol exhibited a less potent effect on H9C2 cell viability compared with DOX; however, catalpol increased the viability of DOX-induced H9C2 cells. Catalpol treatment also significantly decreased the expression levels of inflammatory factors (TNF-α, IL-1β and IL-6) in DOX-induced H9C2 cells, which was reversed by transfections with short hairpin RNA targeting PPAR-γ. Results from the present study indicated that catalpol ameliorated DOX-induced inflammation and oxidative stress in H9C2 cardiomyoblasts by activating PPAR-γ.

Catalpol‑mediated microRNA‑34a suppresses autophagy and malignancy by regulating SIRT1 in colorectal cancer

Colorectal cancer (CRC) is one of the most common digestive tract tumors worldwide. Catalpol exerts inhibitory effects on the progression of several cancer types by regulating microRNAs (miRs). However, the precise role and carcinostatic mechanism of catalpol on CRC cells are poorly understood which limits the application of catalpol treatment. In the present study, miR-34a and sirtuin 1 (SIRT1) expression levels were detected in CRC tissues and CRC cell lines by RT-qPCR. Computational software analysis, luciferase assays and western blotting were used to demonstrate the downstream target of miR-34a in CRC cells. Effects of catalpol on cell viability, apoptosis, autophagic flux and the miR-34a/SIRT1 axis in the CRC cells were assessed by CCK-8 assay, flow cytometry, electron microscopy and western blotting, respectively. Whether the miR-34a/SIRT1 axis participated in catalpol-mediated autophagy and apoptosis was investigated. The effects of catalpol on the miR-34a/SIRT1 axis and malignant behavior were evaluated in a rat model of azoxymethane (AOM)-induced CRC. It was revealed that miR-34a expression levels were significantly decreased while SIRT1 was overexpressed in most of the CRC tissues and all the CRC cell lines. Clinically, a low level of miR-34a was correlated with poor clinicopathological characteristics in CRC patients. Catalpol reduced cell viability, suppressed autophagy, promoted apoptosis, and regulated the expression of SIRT1 by inducing miR-34a in vitro and in vivo. The autophagy-inhibiting effect of catalpol may be a mechanism to promote apoptosis of CRC cells. miR-34a mimic transfection resulted in autophagy-suppressive activity similar to that of catalpol, while the miR-34a inhibitor attenuated the antiautophagic effects of catalpol. In conclusion, miR-34a is involved in regulating catalpol-mediated autophagy and malignant behavior by directly inhibiting SIRT1 in CRC.

Possible involvement of PI3K/AKT/mTOR signaling pathway in the protective effect of selegiline (deprenyl) against memory impairment following ischemia reperfusion in rat

Short-term cerebral ischemia led to memory dysfunction. There is a pressing need to introduce effective agents to reduce complications of the ischemia. Involvement of PI3K/AKT/mTOR signaling pathway has been determined in the neuroprotective effect of various agents. Selegiline (deprenyl) possessed neuroprotective properties. In this study global ischemia/reperfusion was established in rats. Selegiline (5 mg/kg for 7 consecutive days) administrated via intraperitoneal route. Possible involvement of PI3K/AKT/mTOR signaling pathway was evaluated using qRT-PCR, immunohistochemistry and histophatologic evaluations in the hippocampus. Spatial memory was evaluated by morris water maze (MWM). Results showed that ischemia impaired the memory and ischemic rats spent more time to find hidden platform in the MWM. Ischemia significantly decreased levels of PI3K, AKT and mTOR in the hippocampus. Histopathologic assessment revealed that the percent of dark neurons significantly increased in the CA1 area of the hippocampus of ischemic rats. Selegiline improved the memory as ischemic rats spent fewer time to find hidden platform in the MWM. Findings showed that selegiline increased the level and expression of PI3K, AKT and mTOR as well as decreased the proportion of dark neurons in the CA1 area of the pyramidal layer of the hippocampus. We concluded that selegiline, partially at least, through increases the expression of PI3K, AKT and mTOR as well as decreases the percent of dark neurons in the hippocampus could improve the memory impairment following the ischemia in rats.

Traditional oriental medicine for sensorineural hearing loss: Can ethnopharmacology contribute to potential drug discovery?

ETHNOPHARMACOLOGICAL RELEVANCE

In Traditional Oriental Medicine (TOM), the development of hearing pathologies is related to an inadequate nourishment of the ears by the kidney and other organs involved in regulation of bodily fluids and nutrients. Several herbal species have historically been prescribed for promoting the production of bodily fluids or as antiaging agents to treat deficiencies in hearing.

AIM OF REVIEW

The prevalence of hearing loss has been increasing in the last decade and is projected to grow considerably in the coming years. Recently, several herbal-derived products prescribed in TOM have demonstrated a therapeutic potential for acquired sensorineural hearing loss and tinnitus. Therefore, the aims of this review are to provide a comprehensive overview of the current known efficacy of the herbs used in TOM for preventing different forms of acquired sensorineural hearing loss and tinnitus, and associate the traditional principle with the demonstrated pharmacological mechanisms to establish a solid foundation for directing future research.

METHODS

The present review collected the literature related to herbs used in TOM or related compounds on hearing from Chinese, Korean, and Japanese herbal classics; library catalogs; and scientific databases (PubMed, Scopus, Google Scholar; and Science Direct).

RESULTS

This review shows that approximately 25 herbal species and 40 active compounds prescribed in TOM for hearing loss and tinnitus have shown in vitro or in vivo beneficial effects for acquired sensorineural hearing loss produced by noise, aging, ototoxic drugs or diabetes. The inner ear is highly vulnerable to ischemia and oxidative damage, where several TOM agents have revealed a direct effect on the auditory system by normalizing the blood supply to the cochlea and increasing the antioxidant defense in sensory hair cells. These strategies have shown a positive impact on maintaining the inner ear potential, sustaining the production of endolymph, reducing the accumulation of toxic and inflammatory substances, preventing sensory cell death and preserving sensory transmission. There are still several herbal species with demonstrated therapeutic efficacy whose mechanisms have not been deeply studied and others that have been traditionally used in hearing loss but have not been tested experimentally. In clinical studies, Ginkgo biloba, Panax ginseng, and Astragalus propinquus have demonstrated to improve hearing thresholds in patients with sensorineural hearing loss and alleviated the symptoms of tinnitus. However, some of these clinical studies have been limited by small sample sizes, lack of an adequate control group or contradictory results.

CONCLUSIONS

Current therapeutic strategies have proven that the goal of the traditional oriental medicine principle of increasing bodily fluids is a relevant approach for reducing the development of hearing loss by improving microcirculation in the blood-labyrinth barrier and increasing cochlear blood flow. The potential benefits of TOM agents expand to a multi-target approach on different auditory structures of the inner ear related to increased cochlear blood flow, antioxidant, anti-inflammatory, anti-apoptotic and neuroprotective activities. However, more research is required, given the evidence is very limited in terms of the mechanism of action at the preclinical in vivo level and the scarce number of clinical studies published.

Catalpol prevents denervated muscular atrophy related to the inhibition of autophagy and reduces BAX/BCL2 ratio via mTOR pathway

Aim

To investigate the effects of catalpol on muscular atrophy induced by sciatic nerve crush injury (SNCI).

Methods

Seventy male Kunming mice were randomized into five groups (n=10): model, sham, catalpol (Cat), rapamycin (Rapa), and catalpol+rapamycin (Rapa+Cat). The ratio of gastrocnemius muscle wet weight (right/left, R/L) between the operated leg (right) and the normal leg (left) was calculated, and acetylcholinesterase (AChE) immunohistochemistry assays were performed to observe the change of motor end plate (MEP), along with the sizes of denervated and innervated muscle fibers. The expression levels of LC3II, TUNEL, BAX/BCL-2, LC3II/LC3I and P62, Beclin1, mTOR, and p-mTOR (ser2448) proteins in muscle were examined by fluorescence immunohistochemistry or Western blotting.

Results

Results show that catalpol improved the results of the grid walking tests by reducing the percentage of foot slips, which increased the gastrocnemius muscle wet weight (R/L), enhanced AChE expression at the MEP, and enlarged the section area of the muscle. The expression of LC3II and TUNEL was significantly inhibited by catalpol. The BAX/BCL-2 ratio was significantly increased in muscles of denervated and control groups. Lower LC3II/LC3I and BAX/BCL-2 ratios in denervated muscles were also detected after catalpol treatment.

Conclusion

These results indicated that apoptosis and autophagy play a role in the regulation of denervation-induced muscle atrophy after SNCI, and catalpol alleviates muscle atrophy through the regulation of muscle apoptosis and autophagy via the mTOR signaling pathway.

The Antiapoptosis Effect of Geum japonicum Thunb. var. chinense Extracts on Cerebral Ischemia Reperfusion Injury via PI3K/Akt Pathway

Geum japonicum Thunb. var. chinense (GJ) is a type of wild vegetable found in China and other Asian countries; it has been reported that its extracts possess a neuroprotective effect against cerebral ischemia reperfusion (CIR) injury. The aim of this study is to explore the effect GJ extracts on transient focal CIR injury and neurons apoptosis and to clarify its possible underlying mechanisms in vivo. Our results indicated that pretreatment with GJ extracts significantly ameliorated the infarct volume, decreased neurological deficits, lessened neural cells apoptosis, downregulated GFAP activity level, and increased surviving neurons. Moreover, GJ extracts preadministration increased Bcl-2 levels and attenuated the increase in the expressions of Bax and it also lowered the cleaved caspase-3 activity in ischemic cortex tissues which was caused by CIR and increased the expression of PI3K and p-Akt. The above effects of high dose of GJ (GJ-H) group were much better than those of low dose of GJ (GJ-L), which indicated that GJ extracts may be helpful in the suppression of CIR injury with a dose-dependent manner.

The Therapeutic Effect of the Chinese Herbal Medicine, Rehmanniae Radix Preparata, in Attention Deficit Hyperactivity Disorder via Reversal of Structural Abnormalities in the Cortex

Rehmanniae radix preparata is extracted from wine-steaming the Rehmannia root, a scrophulariaceae plant. It has been used for thousands of years with effects of nourishing kidney-yin, benefiting essence and filling marrow based on traditional Chinese medicine (TCM) theory. Rehmanniae radix preparata has antioxidant, antisenescence, anti-inflammatory, and neuroprotective properties. It is the most popular Traditional Chinese medicinal compound (TCMC) used in attention deficit hyperactivity disorder (ADHD) therapy. However, few studies have been conducted exploring the effects and potential mechanisms of Rehmanniae radix preparata alone on ADHD. Recent studies have shown that Rehmanniae radix preparata inhibits spontaneous activity in mice, improves learning and memory in rats following thalamic arcuate nucleus injury, and exhibits antidepressant effects. Catalpol, an active component of Rehmanniae radix preparata, elevates brain-derived neurotrophic factor (BDNF), and attenuates neuronal apoptosis and energy metabolism failure. ADHD is characterized by hyperactivity-impulsivity and impairments in learning and memory. Its pathomechanism is closely related to structural abnormalities in the cortex that is mediated by dysfunction in neuronal development, apoptosis, and energy metabolism. We hypothesize that Rehmanniae radix preparata may be effective at treating ADHD by alleviating neurodevelopmental abnormalities, neuronal apoptosis, and energy metabolism failure.

Role of catalpol in ameliorating the pathogenesis of experimental autoimmune encephalomyelitis by increasing the level of noradrenaline in the locus coeruleus

The endogenous neurotransmitter, noradrenaline, exerts anti-inflammatory and neuroprotective effects in vivo and in vitro. Reduced noradrenaline levels results in increased inflammation and neuronal damage. The primary source of noradrenaline in the central nervous system is tyrosine hydroxylase (TH)-positive neurons, located in the locus coeruleus (LC). TH is the rate-limiting enzyme for noradrenaline synthesis; therefore, regulation of TH protein expression and intrinsic enzyme activity represents the central means for controlling the synthesis of noradrenaline. Catalpol is an iridoid glycoside purified from Rehmannia glutinosa Libosch, which exerts a neuroprotective effect in multiple sclerosis (MS). The present study used an experimental mouse model of autoimmune encephalomyelitis to verify the neuroprotective effects of catalpol. Significant improvements in the clinical scores were observed in catalpol-treated mice. Furthermore, catalpol increased TH expression and increased noradrenaline levels in the spinal cord. In primary cultures, catalpol exerted a neuroprotective effect in rat LC neurons by increasing the noradrenaline output. These results suggested that drugs targeting LC survival and function, including catalpol, may be able to benefit patients with MS.

Effect of catalpol on remyelination through experimental autoimmune encephalomyelitis acting to promote Olig1 and Olig2 expressions in mice

BACKGROUND

Multiple sclerosis (MS) as an autoimmune disorder is a common disease occurring in central nervous system (CNS) and the remyelination plays a pivotal role in the alleviating neurological impairment in the MS. Catalpol, an effective component extracted from the Chinese herb Radix Rehmanniae, which has been proved protective in cerebral diseases.

METHODS

To determine the protective effects and mechanisms of Catalpol on MS, the mice with experimental autoimmune encephalomyelitis (EAE) were induced by myelin oligodendrocyte glycoprotein (MOG) 35-55, as a model for human MS. Th17 cells were counted by flow cytometric (FCM). The expressions of nerve-glial antigen (NG) 2 and myelin basic protein (MBP) were measured by immunohistochemical staining. Olig1+ and Olig2+/BrdU+ cells were counted by immunofluorescence. Olig1 and Olig2 gene expressions were detected by real-time fluorescent quantitative reverse transcription (qRT) -PCR.

RESULTS

The results showed that Catalpol improved neurological function, reduced inflammatory cell infiltration and demyelination. It could decrease Th17 cells in the peripheral blood. It increased the protein expressions of NG2 and MBP in mice brains, up-regulated markedly protein and gene expressions of Olig1 and Olig2 in terms of timing, site and targets.

CONCLUSIONS

These data demonstrated that Catalpol had a strong neuroprotective effect on EAE mice. Catalpol also plays a role in remyelination by promoting the expressions of Olig1 and Olig2 transcription factors.

Effects of long‑term post‑ischemic treadmill exercise on gliosis in the aged gerbil hippocampus induced by transient cerebral ischemia

Therapeutic exercise is an integral component of the rehabilitation of patients who have suffered a stroke. The objective of the present study was to use immunohistochemistry to investigate the effects of post-ischemic exercise on neuronal damage or death and gliosis in the aged gerbil hippocampus following transient cerebral ischemia. Aged gerbils (male; age, 22–24 months) underwent ischemia and were subjected to treadmill exercise for 1 or 4 weeks. Neuronal death was detected in the stratum pyramidale of the hippocampal CA1 region and in the polymorphic layer of the dentate gyrus using cresyl violet and Fluoro-Jade B histofluorescence staining. No significant difference in neuronal death was identified following 1 or 4 weeks of post-ischemic treadmill exercise. However, post-ischemic treadmill exercise affected gliosis (the activation of astrocytes and microglia). Glial fibrillary acidic protein-immunoreactive astrocytes and ionized calcium binding adaptor molecule 1-immunoreactive microglia were activated in the CA1 and polymorphic layer of the dentate gyrus of the group without treadmill exercise. Conversely, 4 weeks of treadmill exercise significantly alleviated ischemia-induced astrocyte and microglial activation; however, 1 week of treadmill exercise did not alleviate gliosis. These findings suggest that long-term post-ischemic treadmill exercise following transient cerebral ischemia does not influence neuronal protection; however, it may effectively alleviate transient cerebral ischemia-induced astrocyte and microglial activation in the aged hippocampus.

Catalpol Protects Pre-Myelinating Oligodendrocytes against Ischemia-induced Oxidative Injury through ERK1/2 Signaling Pathway

The vulnerability of pre-myelinating oligodendrocytes (PreOLs) to ischemic injury plays an important role in the pathogenesis and progression of perinatal white matter injury. Although oxidative stress is thought to be a major pathogenic mechanism predisposing the PreOLs to injury, no effective therapies have been identified to date. The present study aimed to investigate the direct protective effects of catalpol, a potent antioxidant and free radical scavenger, on ischemia-induced oxidative damage in PreOLs and to explore whether the ERK1/2 signaling pathway contributed to the protection provided by catalpol. Primary cultures of PreOLs exposed to oxygen-glucose deprivation (OGD) followed by reperfusion were used as an in vitro model of ischemia. Pretreatment with 0.5 mM catalpol for 1 h prior to OGD treatment significantly reversed ischemia-induced apoptosis in PreOLs and myelination deficits by inhibiting intracellular Ca²⁺ increase, reducing mitochondrial damage, and ameliorating overproduction of reactive oxygen species (ROS). The expression levels of phosphorylated ERK1/2 (p-ERK1/2) and activated poly-ADP-ribose polymerase-1 (PARP-1) were also markedly decreased by catalpol treatment. Blocking the ERK1/2 signaling pathway with the MEK inhibitor U0126 and catalpol significantly protected PreOLs from ROS-mediated apoptosis under OGD. Taken together, these results suggest that catalpol protects PreOLs against ischemia-induced oxidative injury through ERK1/2 signaling pathway. Catalpol may be a candidate for treating ischemic white matter damage.

Aerobic Exercise Promotes a Decrease in Right Ventricle Apoptotic Proteins in Experimental Cor Pulmonale

Pulmonary arterial hypertension is characterized by progressive increases in resistance and pressure in the pulmonary artery and Cor pulmonale. The effect of exercise on hydrogen peroxide-dependent signaling in the right ventricle (RV) of Cor pulmonale rats was analyzed. Rats were divided into sedentary control (SC), sedentary monocrotaline (SM), trained control (TC), and trained monocrotaline (TM) groups. Rats underwent exercise training (60% of VO2 max) for 5 weeks, with 3 weeks after monocrotaline injection (60 mg/kg intraperitoneally). Pulmonary resistance was enhanced in SM (2.0-fold) compared with SC. Pulmonary artery pressure was increased in SM (2.7-fold) and TM (2.6-fold) compared with their respective controls (SC and TC). RV hypertrophy indexes increased in SM compared with SC. Hydrogen peroxide was higher in SM (1.7-fold) than SC and was reduced by 47% in TM compared with SM. p-Akt was increased in TM (2.98-fold) compared with SM. The Bax/Bcl-2 ratio and caspase 3 were also increased (2.9-fold and 3.9-fold, respectively) in SM compared with SC. Caspase 3 was decreased in TM compared with SM (P < 0.05). Therefore, exercise training promoted a beneficial response by decreasing hydrogen peroxide concentrations, and consequently, apoptotic signaling in RV.

Catalpol inhibits apoptosis in hydrogen peroxide-induced cardiac myocytes through a mitochondrial-dependent caspase pathway

These findings indicated for the first time that pretreatment of H9c2 cells with catalpol can against H₂O₂-induced apoptosis, and the protective effect of catalpol via a mitochondrial-dependent caspase pathway and is associated with increased Bcl-2 and decreased Bax expression.

Catalpol, an iridoid glucoside, has been reported to inhibit apoptosis of neuron and endothelial cells. In the present study, we investigated the mechanism of catalpol-mediated cardioprotection. The rat embryonic ventricular myocardial cell line (H9c2) cells were first incubated with catalpol, and then exposed to hydrogen peroxide (H₂O₂). The concentration of malondialdehyde (MDA) and the activity of superoxide dismutase (SOD) were all determined by using commercially available kits. Apoptotic cells were assessed by Hoechst 33258 and Annexin V-fluorescein isothiocyanate binding assay. Synthesis of Bcl-2, Bax, cytochrome c and caspase-3 were analysed by real-time semiquantitative reverse transcription-PCR and Western blotting. We observed that apoptosis in H9c2 was associated with increased Bax, cytochrome c, caspase-3, decreased Bcl-2 activity after 24 h of H₂O₂ exposure. Catalpol pretreatment afforded a marked protection against the above H₂O₂-mediated cytotoxicity and apoptosis in H9c2 cells. Moreover, the catalpol pretreatment led to a great reduction in H₂O₂-induced MDA release and increased SOD. These findings indicated for the first time that pretreatment of H9c2 cells with catalpol can be against H₂O₂-induced apoptosis, and the protective effect of catalpol involves the mitochondrial-dependent caspase pathway and is associated with increased Bcl-2 and decreased Bax expression.

Catalpol downregulates vascular endothelial‑cadherin expression and induces vascular hyperpermeability

Catalpol, an iridiod glucoside isolated from Rehmannia glutinosa, has been reported to possess anti‑inflammatory properties. However, the molecular mechanisms underlying this effect have not been fully elucidated. This study aimed to investigate the effects of catalpol on vascular permeability. Using Transwell permeability assays and measurements of trans‑endothelial electrical resistance (TEER), it was demonstrated that 1 mM catalpol induces a significant increase in the permeability of the monolayers of human umbilical vein endothelial cells (HUVECs). Western blotting and immunofluorescence demonstrated that catalpol inhibits the expression of vascular endothelial (VE)‑cadherin, the key component of adherens junctions, but not occludin, the major constituent of tight junctions. In addition, catalpol inhibits the ETS transcription factor ERG, a positive regulator of VE‑cadherin. Knockdown of ERG expression compromised the catalpol‑induced reduction of TEER in HUVECs. The present study revealed a novel effect of catalpol on vascular permeability and gave insight into the multifaceted roles of catalpol in inflammation.

Alpha lipoic acid (ALA) modulates expression of apoptosis associated proteins in hippocampus of rats exposed during postnatal period to sodium arsenite (NaAsO2)

The present study focused on the role of exogenous alpha lipoic acid (ALA) in amelioration of inorganic arsenic (iAs) induced effects on apoptosis and apoptosis associated proteins in developing rat hippocampus. NaAsO2 (1.5/2.0 mg/kg bw) alone or along with ALA (70 mg/kg bw) was administered to rat pups (experimental groups) by intraperitoneal (i.p.) route from postnatal day (PND) 4-15. Controls received no treatment/distilled water/ALA. On PND 16, the animals were perfusion fixed and the brains were processed for paraffin embedding (CV and TUNEL staining) and cryopreservation (immunohistochemistry). The fresh brain tissue was used for Western blotting. Significant increase was observed in TUNEL positive cells and Bax (pro-apoptotic protein) expression in hippocampal sub-regions of iAs alone treated groups, whereas Bcl-2 expression was intensified in animals receiving ALA with iAs. Densitometric analysis (Western blots) revealed optimal restoration of Bax and Bcl-2 ratio in animals receiving ALA with iAs, thereby suggesting the protective role of ALA in iAs induced developmental neurotoxicity.

Catalpol provides protective effects against cerebral ischaemia/reperfusion injury in gerbils

Objectives

To investigate the protective effect of catalpol on cerebral ischaemia/reperfusion (CI/R) injury in gerbils and further explore the underlying mechanism.

Methods

A gerbil model of CI/R was prepared by bilateral common carotid occlusion for 10 min followed by 6 h reperfusion. Catalpol (5, 10 or 20 mg/kg per day) was injected intraperitoneally for 3 days before the carotid occlusion. Stroke index was measured during the reperfusion. The contents of endogenous neuropeptides, endothelin-1 (ET-1) and calcitonin gene-related peptide in plasma were evaluated by radioimmunoassay. Superoxide dismutase (SOD) and malondialdehyde (MDA) in brain tissue homogenate were also examined.

Key findings

The results showed that catalpol significantly improved the stroke index compared with CI/R control group (P &lt; 0.05 or P &lt; 0.01). Catalpol significantly increased the activity of SOD at the doses of 10 and 20 mg/kg (P ≤ 0.05), decreased the brain MDA content and the plasma level of ET-1 at the doses of 10 and 20 mg/kg (P ≤ 0.01).

Conclusions

These data suggested that the efficacy of catalpol pretreatment on CI/R injury may be attributed to reduction of free radicals and inhibition of lipid peroxidation and ET-1 production.

Catalpol decreases peroxynitrite formation and consequently exerts cardioprotective effects against ischemia/reperfusion insult

CONTEXT

Peroxynitrite (ONOO(-)) formation triggers oxidative/nitrative stress and contributes to exacerbated myocardial ischemia/reperfusion (MI/R) injury. Catalpol, an iridoid glycoside, abundantly found in the roots of Rehmannia glutinosa L. that is included in the family Phrymaceae in the order Lamiales, endemic to China, was found to have neuroprotective effects. However, the effect of catalpol on MI/R injury has not been identified.

OBJECTIVE

This study investigated whether catalpol attenuates oxidative/nitrative stress in acute MI/R.

MATERIALS AND METHODS

Adult male rats were subjected to 30 min of myocardial ischemia and 3 h of reperfusion and were treated with saline, catalpol (5 mg/kg, i.p., 5 min before reperfusion) or catalpol plus wortmannin (15 µg/kg intraperitoneally injected 15 min before reperfusion).

RESULTS

Pretreatment with catalpol significantly improved cardiac functions, reduced myocardial infarction, apoptosis and necrosis of cardiomyocytes after MI/R (all p < 0.05). Meanwhile, ONOO(-) formation was markedly reduced after catalpol treatment (3.01 ± 0.22 vs. 4.66 ± 0.53 pmol/mg protein in vehicle, p < 0.05). In addition, catalpol increased Akt and endothelial nitric oxide synthase phosphorylation, nitric oxide (NO) production, anti-oxidant capacity and reduced MI/R-induced inducible nitric oxide synthase expression and superoxide anion (·O(2)(-)) production in I/R hearts. PI3K inhibitor wortmannin not only blocked catalpol-induced Akt activation, but also attenuated all the beneficial effects of catalpol. Suppression of ONOO(-) formation by either catalpol or an ONOO(-) scavenger uric acid (5 mg/kg) reduced myocardial infarct size in MI/R rats.

DISCUSSION AND CONCLUSION

In conclusion, catalpol affords cardioprotection against MI/R insult by attenuating ONOO(-) formation, which is attributable to increased physiological NO and decreased ·O(2)(-) production.

Radio-protective effect of catalpol in cultured cells and mice

Ionizing radiation can induce DNA damage and cell death by generating reactive oxygen species (ROS). The objective of this study was to investigate the radio-protective effect of catalpol (a main bioactive component in the traditional Chinese Rehmannia) on irradiated cells and mice. We found that treating cells with catalpol (25-100 μg/ml) before irradiation could significantly inhibit ionizing radiation (IR)-induced human lymphocyte AHH-1 cells apoptosis and increase cells viability in vitro. At the same time our study also showed that catalpol (25-100 mg/kg) reduced morphological damage of the gastrointestinal tract by 15.6%, 33.3% and 44.4%, respectively compared with the radiation-induced group, decreased plasma malondialdehyde (MDA) intestinal 8-hydroxydeoxyguanosine (8-OHdG) levels and increased plasma endogenous antioxidants and peripheral white blood cells and platelets in vivo. These results suggest that catalpol possesses notable radio-protective activity, which might be related to its effect of reducing ROS.

Curcumin and resveratrol in combination modulates benzo(a)pyrene-induced genotoxicity during lung carcinogenesis

The present study attempted to explore the efficacy of curcumin and resveratrol in modulating mitotic catastrophe and apoptosis during lung carcinogenesis. The mice were segregated into five groups, which included normal control, benzo(a)pyrene (BP)-treated, BP + curcumin (C)-treated, BP + resveratrol (R)-treated and BP + C + R-treated groups. The BP treatment resulted in a significant increase in the formation of micronuclei as well as in the protein expression of bcl-2 in the lungs of mice. On the other hand, a significant decrease was observed in the number of apoptotic cells and protein expression of bax in the lungs of BP-treated mice. Supplementation of curcumin and resveratrol individually to BP-treated animals resulted in a decrease in the micronuclei formation; however, it was not statistically significant. Interestingly, combination of curcumin and resveratrol resulted in a statistically significant decrease in micronuclei formation. Moreover, phytochemicals in combination significantly reduced the protein expression of bcl-2 in BP-treated mice. Furthermore, supplementation of phytochemicals in combination brought a noticeable improvement in the number of apoptotic cells as well as in the protein expression of bax. The present study, therefore, concludes that the combined treatment with curcumin and resveratrol modulates mitotic catastrophe by stimulating apoptosis in BP-treated mice.

Increases of antioxidants are related to more delayed neuronal death in the hippocampal CA1 region of the young gerbil induced by transient cerebral ischemia

In age-related studies, young animals are resistant to ischemic damage. In present study, we investigated the neuronal death of pyramidal neurons and compared changes in the immunoreactivities and levels of antioxidants, Cu/Zn-SOD (SOD1), Mn-SOD (SOD2), catalase (CAT) and glutathione peroxidase (Gpx), in the hippocampal CA1 region between adult and young gerbils after 5 min of transient cerebral ischemia. In the adult ischemia-group, only a few (12%) of CA1 pyramidal neurons survived 4 days after ischemia-reperfusion (I-R); however, in the 4 days after I-R the young group, most of CA1 pyramidal neurons survived. Seven days after I-R, many (about 39%) of CA1 pyramidal neurons survived, thereafter, the neuronal death in the CA1 pyramidal neurons was not significantly changed. The immunoreactivities of all the antioxidants were well detected in CA1 pyramidal neurons in the adult sham-groups; in the young sham-groups, they were distinctively low compared to those in the adult sham-group. Four days after I-R in the adult group, all the immunoreactivities in the pyramidal neurons were dramatically deceased. However, at this time after I-R in the young groups, they were dramatically increased in the pyramidal neurons. From 7 days after I-R, all the immunoreactivities in the pyramidal neurons in the young ischemia-groups were distinctively decreased. In addition, the levels of all the antioxidants in the CA1 region of the young sham-groups were lower than those in the adult sham-group. Four days after I-R in the adult groups, the levels of all the antioxidants were dramatically deceased; however, at this time in the young ischemia-groups, they were distinctively increased in the CA1 region. Seven days after I-R, all the antioxidants levels in the CA1 region were distinctively decreased. In brief, we conclude that the increased antioxidants levels were related to a less and much delayed neuronal death in the CA1 pyramidal neurons in the young group following I-R injury.

Traditional chinese medicine for senile dementia

Traditional Chinese Medicine (TCM) has a 3000 years' history of human use. A literature survey addressing traditional evidence from human studies was done, with key result that top 10 TCM herb ingredients including Poria cocos, Radix polygalae, Radix glycyrrhizae, Radix angelica sinensis, and Radix rehmanniae were prioritized for highest potential benefit to dementia intervention, related to the highest frequency of use in 236 formulae collected from 29 ancient Pharmacopoeias, ancient formula books, or historical archives on ancient renowned TCM doctors, over the past 10 centuries. Based on the history of use, there was strong clinical support that Radix polygalae is memory improving. Pharmacological investigation also indicated that all the five ingredients mentioned above can elicit memory-improving effects in vivo and in vitro via multiple mechanisms of action, covering estrogen-like, cholinergic, antioxidant, anti-inflammatory, antiapoptotic, neurogenetic, and anti-Aβ activities. Furthermore, 11 active principles were identified, including sinapic acid, tenuifolin, isoliquiritigenin, liquiritigenin, glabridin, ferulic acid, Z-ligustilide, N-methyl-beta-carboline-3-carboxamide, coniferyl ferulate and 11-angeloylsenkyunolide F, and catalpol. It can be concluded that TCM has a potential for complementary and alternative role in treating senile dementia. The scientific evidence is being continuously mined to back up the traditional medical wisdom.

Baicalin attenuates global cerebral ischemia/reperfusion injury in gerbils via anti-oxidative and anti-apoptotic pathways

Baicalin is an important medicinal herb purified from the dry roots of Scutellaria baicalensis Georgi. The present study was undertaken to evaluate the neuroprotective effects of baicalin in gerbils subjected to transient global cerebral ischemic-reperfusion injury. Baicalin at doses of 50, 100 and 200mg/kg was intraperitoneally injected into the gerbils immediately after cerebral ischemia. Seven days after reperfusion, hematoxylin and eosin (HE) staining was performed to analyze hippocampal CA1 pyramidal damage histopathologically. In addition, in order to understand the potential protective mechanism of baicalin, we examined anti-oxidative enzymes, such superoxide dismutase (SOD), glutathione peroxidase (GSH-PX), non-enzymatic scavenger glutathione (GSH) and measured the content of malondialdehyde (MDA) in hippocampus. The mRNA and protein expressions of BDNF were determined in ischemic hippocampus by real-time RT-PCR and Western blot, respectively. Evidence for neuronal apoptosis was detected by real-time RT-PCR, Western blot and caspase-3 activity measurement. Histopathological examination showed that the administration of baicalin by the dose of 100 and 200mg/kg significantly attenuated ischemia-induced neuronal cell damage. Reduced level of MDA, obviously elevated activities of SOD and GSH as well as GSH-PX were also found in baicalin-treated groups. Further investigation demonstrated that treatment with baicalin remarkably promoted the expression of BDNF and inhibited the expression of caspase-3 at mRNA and protein levels by real-time RT-PCR and Western blot, respectively. Besides, caspase-3 activity assay also elucidated that the administration of baicalin could significantly suppress caspase-3 in ischemic gerbils hippocampus. Theses findings suggest that baicalin's neuroprotection appears to be associated with its anti-oxidative and anti-apoptotic properties in global cerebral ischemia in the gerbils.

Catalpol increases brain angiogenesis and up-regulates VEGF and EPO in the rat after permanent middle cerebral artery occlusion

To investigate the role and mechanism of catalpol in brain angiogenesis in a rat model of stroke, the effect of catalpol (5 mg/kg; i.p) or vehicle administered 24 hours after permanent middle cerebral artery occlusion (pMCAO) on behavior, angiogenesis, ultra-structural integrity of brain capillary endothelial cells, and expression of EPO and VEGF were assessed. Repeated treatments with Catalpol reduced neurological deficits and significantly improved angiogenesis, while significantly increasing brain levels of EPO and VEGF without worsening BBB edema. These results suggested that catalpol might contribute to infarcted-brain angiogenesis and ameliorate the edema of brain capillary endothelial cells (BCECs) by upregulating VEGF and EPO coordinately.

Catalpol inhibits apoptosis in hydrogen peroxide-induced endothelium by activating the PI3K/Akt signaling pathway and modulating expression of Bcl-2 and Bax

Catalpol, an iridoid glucoside found in the root of Rehmannia glutinosa Libosch, has been demonstrated to reduce apoptosis in neuronal cell lines. Recent data suggests that catalpol also exerts anti-apoptotic effects on other cell types. The aim of the present study was to investigate whether catalpol protects against hydrogen peroxide (H(2)O(2)) induced apoptosis in human umbilical vein endothelial cells (HUVECs). Apoptotic cells were detected by terminal deoxyribonucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end labeling, Annexin V-fluorescein isothiocyanate binding assay and by assessment of caspase-3 activity. The level of intracellular reactive oxygen species was quantified by 2', 7'-dichlorofluorescein diacetate assay. Expression of Akt, Bad, Bcl-2 and Bax mRNA and protein was determined by real-time semiquantitative reverse transcription-polymerase chain reaction and Western blotting. Apoptosis in HUVECs was associated with increased Bax, decreased Bcl-2 activity and inactivated phosphorylation of Akt and Bad after 24h of H(2)O(2) exposure. Pre-treatment of HUVECs with catalpol significantly reduced H(2)O(2)-induced intracellular reactive oxygen species release. Catalpol not only increased the expression of Bcl-2, while decreasing Bax expression, but also induced Akt activation and Bad phosphorylation, and ultimately reduced H(2)O(2)-induced apoptosis. The protective effects of catalpol were partially inhibited by the phosphatidylinositol 3-kinase (PI3K) antagonist wortmannin or 2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one (LY294002). Taken together, these results suggest that pre-treatment of HUVECs with catalpol can block H(2)O(2)-induced apoptosis, and that the underlying mechanism involves reactive oxygen species scavenging, activation of the PI3K/Akt-Bad signaling pathway and increased Bcl-2 and decreased Bax expression.

Rehmannia glutinosa ameliorates the progressive renal failure induced by 5/6 nephrectomy

AIM OF THE STUDY

Rehmannia glutinosa, the steamed root of the Scrophulariaceae family, has been widely used in Asian countries for the treatment of renal diseases. In this study, we evaluated the renoprotective effect of aqueous extract of Rehmannia glutinosa in progressive renal failure.

MATERIALS AND METHODS

The effects of Rehmannia glutinosa on renal function, 24-h proteinuria, and the expression of angiotensin II, angiotensin II type 1 (AT(1)) receptor, TGF-beta1, and type IV collagen in renal cortex were analyzed in progressive renal failure rats induced by 5/6 nephrectomy.

RESULTS

Rehmannia glutinosa reduced the serum creatinine level, 24-h urinary protein excretion, and glomerulosclerosis, and it also inhibited the expression of angiotensin II, AT(1) receptor, TGF-beta1 and type IV collagen in the renal cortex.

CONCLUSIONS

These results suggest that the renoprotective effect of Rehmannia glutinosa might be mediated by suppressing the expression of angiotensin II and AT(1) receptor and by regulating TGF-beta1 and type IV collagen expression.

Adopted cognitive tests for gerbils: validation by studying ageing and ischemia

Transient occlusion of common carotid arteries in gerbils is a simple and widely used model for assessing histological and functional consequences of transient forebrain ischemia and neuroprotective action of pharmaceuticals. In the present study we aimed to introduce additional behavioural tests as novel object recognition and food-motivated hole-board learning in order to measure attention and learning capacity in gerbils. For validating these cognitive tests the effects of ageing (4, 9 and 18 months) and those of transient forebrain ischemia induced by bilateral carotid occlusion at 9 months of age were investigated. Neuronal cell death was estimated in the hippocampus using TUNEL and caspase-3 double fluorescence labelling and confocal microscopy. Ageing within the selected range although influenced ambulatory activity, did not considerably change attention and memory functions of gerbils. As a result of transient ischemia a selective neuronal damage in CA1 and CA2 regions of the hippocampus has been observed and tested 4 days after the insult. Ischemic gerbils became hyperactive, but showed decreased attention and impaired spatial memory functions as compared to sham-operated controls. According to our results the novel object recognition paradigm and the hole-board spatial learning test could reliably be added to the battery of conventional behavioural tests applied previously in this species. The novel tests can be performed within a wide interval of adult age and provide useful additional methods for assessing ischemia-induced cognitive impairment in gerbils.

Surface Modification of RGD-Liposomes for Selective Drug Delivery to Monocytes/Neutrophils in Brain

In the present study, RGD peptide was coupled with ferulic acid (FA) liposomes for binding to monocytes and neutrophils in peripheral blood for brain targeting in response to leukocyte recruitment. Cholesterol (Ch) was esterified with succinic anhydride to introduce a carboxylic end group (Ch-COOH). Soybean phosphatidylcholine, cholesterol and Ch-COOH were in a molar ratio of 1 : 0.23 : 0.05. FA was loaded into liposomes with 80.2+/-5.2% entrapment efficiency (EE) using a calcium acetate gradient method since it was difficult to load FA by other methods. RGD peptide was a novel compound coupled with Ch-COOH via carbodiimide and N-hydroxysulfosuccinimide. The results of the in vitro flow cytometric study showed that RGD conjugation liposomes (RGD-liposomes) could bind to monocytes/neutrophils efficiently. The rats were subjected to intrastriatal microinjections of 100 microl of human recombinant IL-1beta to produce brain inflammation and subsequently sacrificed after 15, 30, 60 and 120 min of administration of three formulations (FA solution, FA liposome, RGD-coated FA liposome). The body distribution results showed that RGD-liposomes could be directed to the target site, i.e. the brain, by cell selectivity in case of an inflammatory response. For RGD coated liposomes, the concentration of FA in brain was 6-fold higher than that of FA solution and 3-fold higher than that of uncoated liposomes. MTT assay and flow cytometry were used in the pharmacodynamic studies where it was found that FA liposomes exhibited greater antioxidant activity to FA solution on U937 cell.