Neuroprotective properties of picroside II in a rat model of focal cerebral ischemia

Therapeutic potential of plant iridoids in depression: a review

CONTEXT

Depression is a mental disorder characterized by low mood, reduced interest, impaired cognitive function, and vegetative symptoms such as sleep disturbances or poor appetite. Iridoids are the active constituents in several Chinese classical antidepressant formulae such as Yueju Pill, Zhi-Zi-Hou-Po Decoction, Zhi-Zi-Chi Decoction, and Baihe Dihuang Decoction. Parallel to their wide usages, iridoids are considered potential lead compounds for the treatment of neurological diseases.

OBJECTIVE

The review summarizes the therapeutic potential and molecular mechanisms of iridoids in the prevention or treatment of depression and contributes to identifying research gaps in iridoids as potential antidepressant medication.

METHODS

The following key phrases were sought in PubMed, Google Scholar, Web of Science, and China National Knowledge Internet (CNKI) without time limitation to search all relevant articles with in vivo or in vitro experimental studies as comprehensively as possible: ('iridoid' or 'seciridoid' or 'depression'). This review extracted the experimental data on the therapeutic potential and molecular mechanism of plant-derived iridoids for depression.

RESULTS

Plant iridoids (i.e., catalpol, geniposide, loganin), and secoiridoids (i.e., morroniside, gentiopicroside, oleuropein, swertiamarin), all showed significant improvement effects on depression.

DISCUSSION AND CONCLUSIONS

Iridoids exert antidepressant effects by elevating monoamine neurotransmitters, reducing pro-inflammatory factors, inhibiting hypothalamic-pituitary-adrenal (HPA) axis hyperactivity, increasing brain-derived neurotrophic factor (BDNF) and its receptors, and elevating intestinal microbial abundance. Further detailed studies on the pharmacokinetics, bioavailability, and key molecular targets of iridoids are also required in future research, ultimately to provide improvements to current antidepressant medications.

Bioactives and functional food ingredients with promising potential for the management of cerebral and myocardial ischemia: a comprehensive mechanistic review

Ischemia is a deadly disease featured by restricted perfusion to different organs in the body. An increase in the accumulation of reactive oxygen species and cell debris is the driving force for inducing many oxidative, inflammatory and apoptotic signaling pathways. However, the number of therapeutics existing for ischemic stroke patients is limited and there is insufficient data on their efficiency, which warrants the search for novel therapeutic candidates from natural sources. Herein, a comprehensive survey was done on the reported functional food bioactives (ca. 152 compounds) to manage or protect against health consequences of myocardial and cerebral ischemia. Furthermore, we reviewed the reported mechanistic studies for their anti-ischemic potential. Subsequently, network pharmacology- and in silico-based studies were conducted using the reported myocardial and cerebral ischemia-relevant molecular targets to study their complex interactions and highlight key targets in disease pathogenesis. Subsequently, the most prominent 20 compounds in the literature were used in a comprehensive in silico-based analysis (inverse docking, ΔG calculation and molecular dynamics simulation) to determine other potential targets for these compounds and their probable interactions with different signaling pathways relevant to this disease. Many functional food bioactives, belonging to different chemical classes, i.e., flavonoids, saponins, phenolics, alkaloids, iridoids and carotenoids, were proven to exhibit multifactorial effects in targeting the complex pathophysiology of ischemic conditions. These merits make them valuable therapeutic agents that can outperform the conventional drugs, and hence they can be utilized as add-ons to the conventional therapy for the management of different ischemic conditions; however, their rigorous clinical assessment is necessary.

Neuroprotective Phytochemicals in Experimental Ischemic Stroke: Mechanisms and Potential Clinical Applications

Ischemic stroke is a challenging disease with high mortality and disability rates, causing a great economic and social burden worldwide. During ischemic stroke, ionic imbalance and excitotoxicity, oxidative stress, and inflammation are developed in a relatively certain order, which then activate the cell death pathways directly or indirectly via the promotion of organelle dysfunction. Neuroprotection, a therapy that is aimed at inhibiting this damaging cascade, is therefore an important therapeutic strategy for ischemic stroke. Notably, phytochemicals showed great neuroprotective potential in preclinical research via various strategies including modulation of calcium levels and antiexcitotoxicity, antioxidation, anti-inflammation and BBB protection, mitochondrial protection and antiapoptosis, autophagy/mitophagy regulation, and regulation of neurotrophin release. In this review, we summarize the research works that report the neuroprotective activity of phytochemicals in the past 10 years and discuss the neuroprotective mechanisms and potential clinical applications of 148 phytochemicals that belong to the categories of flavonoids, stilbenoids, other phenols, terpenoids, and alkaloids. Among them, scutellarin, pinocembrin, puerarin, hydroxysafflor yellow A, salvianolic acids, rosmarinic acid, borneol, bilobalide, ginkgolides, ginsenoside Rd, and vinpocetine show great potential in clinical ischemic stroke treatment. This review will serve as a powerful reference for the screening of phytochemicals with potential clinical applications in ischemic stroke or the synthesis of new neuroprotective agents that take phytochemicals as leading compounds.

The beneficial pharmacological effects and potential mechanisms of picroside II: Evidence of its benefits from in vitro and in vivo

Picrorhiza kurroa, the dried rhizome of Picrorhiza kurroa Royle ex Benth, is a famous Chinese herb that has been traditionally used in China. Picroside II (PII), a glycoside derivative, is the main bioactive constituent of Picrorhiza kurroa. In the past several decades, bioactive components from Picrorhiza kurroa have attracted the attention of researchers due to their promising therapeutic effects. A large number of studies have demonstrated the therapeutic potential of PII for the prevention and treatment of some diseases, such as organic ischemia/reperfusion (I/R) injury, liver damage, inflammation, cancer metastasis and angiogenesis. In the present paper, we aimed to provide an overview of the pharmacology of PII, focusing on its anti-oxidant, anti-inflammatory and anti-apoptotic activities. Meanwhile, the plant tissue distribution and pharmacokinetic properties were also described. Due to its beneficial pharmacological effects in I/R injury, PII may serve as a promising therapeutic agent for organic I/R injury prevention.

Chemical components, pharmacological actions, and clinical applications of Rhizoma Picrorhizae

Rhizoma Picrorhizae (RP) is a traditional Chinese medicine, which has always been used to treat many diseases like infantile epilepsy and malnutrition. In modern applications, it has been used to treat hepatitis B and various liver injuries with remarkable curative effects. So far, more than 90 chemical components have been reported in RP, mainly including iridoid glycosides, cucurbitacins, phenylethanoid glycosides, and phenolic glycosides. Among these, iridoid glycosides are the most important active ingredients, and about 30 such compounds have been isolated at present. In pharmacology, RP is beneficial to the choleresis, liver protection, anti-inflammation, asthma relief, immune regulation, and protection of heart, brain, kidney, and other organs. There have been many investigations on this medicinal herb in recent years, and it has attracted much attention in the medicine domain. In this paper, through systematically consulting the relevant books and electronic databases, we analyzed, arranged, and summarized the available information on this herb to provide reference for its further research.

"Picrosides" from Picrorhiza kurroa as potential anti-carcinogenic agents

The steady rise in life expectancy, modern life style and changing environmental conditions are responsible for increasing incidence of cancer. A number of chemical drugs have been used for cancer treatment; however the induction of genotoxic, carcinogenic and teratogenic effects limits their use. Alternatively, plant phytochemicals have been proven effective chemopreventive agents. This review illustrates the use of "picrosides" derived from Picrorhiza kurroa for the treatment of cancer. We have detailed the anti-oxidant and anti-inflammatory action of picrosides as the key mechanism in reducing oncogenesis. Action of picrosides on detoxifying enzymes, cell cyle regulation and induction of signal transducers inhibiting apoptosis has also been reviewed. The present review highlights the use of picrosides as an important therapeutic agent against different types of cancer.

Ghrelin protects the myocardium with hypoxia/reoxygenation treatment through upregulating the expression of growth hormone, growth hormone secretagogue receptor and insulin-like growth factor-1, and promoting the phosphorylation of protein kinase B

Ghrelin is an endogenous ligand of growth hormone (GH) secretagogue receptor (GHSR) and has a number of biological effects, including heart protection. The present study aimed to reveal the positive effect of ghrelin on myocardium with hypoxia/reoxygenation (H/R) treatment and the involved molecular mechanisms. Successful construction of lentiviral expression vector (ghrelin-pLVX-Puro) was confirmed by colony polymerase chain reaction (PCR) verification. Primary rat cardiac myocytes were isolated and identified by immunofluorescence staining. Existence of red fluorescence of α-sarcomeric actinin indicated the successful isolation. Following ghrelin transfection and H/R treatment, primary cells were divided into four groups: Control, H/R, empty (empty pLVX-Puro + H/R) and ghrelin (ghrelin-pLVX-Puro + H/R). Cell viability and apoptosis were evaluated by Cell Counting Kit-8 (CCK-8) and Hoechst staining, respectively. The cell viability in the ghrelin group was significantly higher than that in the empty control group (P<0.05). The apoptosis rate in the ghrelin group was significantly lower than that in the empty control group (P<0.05). An ex vivo rat cardiac perfusion model was established. Following ghrelin incubation and H/R treatment, ex vivo myocardium was divided into four groups: Control, sham, H/R and ghrelin (ghrelin + H/R). Immunohistochemical analysis demonstrated that ghrelin increased the integrity of cardiac myocytes, and decreased shrinkage and apoptosis. mRNA and protein expression levels of GH, GHSR, insulin-like growth factor-1 (IGF-1), protein kinase B (Akt), phosphorylated Akt (p-Akt) were determined by reverse transcription (RT)-PCR, western blot analysis and immunohistochemical analysis. Ghrelin upregulated the mRNA and protein expression levels of GH, GHSR and IGF-1, and increased the ratio of p-Akt to Akt protein level (p-Akt/Akt) in cardiac myocytes and myocardial tissues with H/R treatment. In conclusion, ghrelin protected the myocardium with H/R treatment through upregulating the expression of GH, GHSR and IGF-1, and promoting the phosphorylation of Akt. This would provide promising insights into the treatment of hypoxic myocardial injury by ghrelin.

[Effects of hypoxia-inducible factor 1α on hypoxic tolerance of human amniotic mesenchymal stem cells]

Objective

Under hypoxic conditions, the survival and apoptosis of human amniotic mesenchymal stem cells (hAMSCs) were observed by transient transfection of hypoxia-inducible factor 1α (HIF-1α) gene, to investigate the effect of HIF-1α on hypoxic tolerance of hAMSCs.

Methods

The hAMSCs were isolated and cultured from amniotic membrane tissue from voluntary donors who were treated with cesarean section. And the morphological observation by inverted phase contrast microscope and immunofluorescence detection of the expressions of stem cell markers OCT-4 and NANOG were performed to identify the cultured cells. The third generation hAMSCs were treated with 200 μmol/L CoCl 2, and transient transfection of plasmids were added according to the following grouping: group A was hAMSCs blank group; group B was pcDNA3.1 negative control group; group C was short hairpin RNA (shRNA) negative control group; group D was shRNA-HIF-1α interference group; group E was pcDNA3.1-HIF-1α over expression group. Cell survival rate of each group was measured by cell counting kit 8 (CCK-8) at 12, 24, 48 hours after hypoxia treatment. Flow cytometry was used to detect apoptosis rate of each group at 24 hours after hypoxia treatment. The expression levels of HIF-1α, vascular endothelial growth factor (VEGF), B-cell lymphoma 2 (Bcl-2), Bax, and cleaved Caspase-3 (C-Caspase-3) proteins were detected by Western blot at 24 hours after hypoxia treatment.

Results

CCK-8 assay showed that the cell survival rate of group D was significantly lower than those of groups A and C at all time points after hypoxia treatment; while the cell survival rate in group E was significantly increased than those in groups A and B, and the diffrences at 24 hours were significant ( P<0.05). In group E, the cell survival rate at 24 hours was significantly higher than those at 12 and 48 hours ( P<0.05). The results of flow cytometry showed that the apoptosis rate in group D was significantly higher than those in groups A and C ( P<0.05), and the apoptosis rate in group E was significantly lower than those in groups A and B ( P<0.05). Western blot showed that the expressions of HIF-1α, VEGF, and Bcl-2 proteins in group D were significantly decreased when compared with those in groups A and C, and the expressions of Bax and C-Caspase-3 proteins were significantly increased ( P<0.05). On the contrary, the expressions of HIF-1α, VEGF, and Bcl-2 proteins in group E were significantly higher than those in groups A and B, and the expressions of Bax and C-Caspase-3 proteins were significantly decreased ( P<0.05).

Conclusion

Overexpression of HIF-1α gene can significantly improve hAMSCs tolerance to hypoxia, the mechanism may be related to up-regulation of VEGF and Bcl-2 expressions, and down-regulation of Bax and C-Caspase-3 expressions.

Activated carbon N-acetylcysteine microcapsule protects against nonalcoholic fatty liver disease in young rats via activating telomerase and inhibiting apoptosis

Non-alcoholic fatty liver disease (NAFLD) is becoming one of the world's most common chronic liver diseases in childhood, yet no therapy is available that has been approved by the food and drug administration (FDA). Previous studies have reported that telomere and telomerase are involved the development and progression of NAFLD. This study was designed to investigate the potential beneficial effects of activated carbon N-acetylcysteine (ACNAC) microcapsules on the development of NAFLD in young rats as well as the underlying mechanism(s) involved. Three-week old male Sprague Dawley rats were given high-fat diet (HFD) with/without ACNAC treatment for 7 consecutive weeks. Liver pathologies were determined by hematoxylin and eosin (H&E) and Oil Red O staining, as well as by changes in biochemical parameters of plasma alanine transaminase (ALT) and aspartate transaminase (AST) levels, respectively. Glucose homeostasis was evaluated by the glucose tolerance test and the liver telomere length and activity were measured by real time PCR and telomeric repeat amplification protocol (TRAP). Western blot analysis was performed to determine the expression level of Bcl-2, Bax and Caspase-3. Our results demonstrated that ACNAC supplementation improved liver pathologies of rats that received long-term HFD feeding. ACNAC supplementation prevented HFD-induced telomere shortening and improved telomerase activity. Moreover, in comparison to HFD-fed rats, ACNAC supplementation markedly increased the expression of Bcl-2, but significantly decreased the expression of Bax and Caspase-3 in juvenile rats. Together, these results indicate that ACNAC may be a promising choice for preventing and treating NAFLD among children.

miR-19a protects cardiomyocytes from hypoxia/reoxygenation-induced apoptosis via PTEN/PI3K/p-Akt pathway

miRNAs have been implicated in processing of cardiac hypoxia/reoxygenation (H/R)-induced injury. Recent studies demonstrated that miR-19a might provide a potential cardioprotective effect on myocardial disease. However, the effect of miR-19a in regulating myocardial ischemic injury has not been previously addressed. The present study was to investigate the effect of miR-19a on myocardial ischemic injury and identified the potential molecular mechanisms involved. Using the H/R model of rat cardiomyocytes H9C2 in vitro, we found that miR-19a was in low expression in H9C2 cells after H/R treatment and H/R dramatically decreased cardiomyocyte viability, and increased lactate dehydrogenase (LDH) release and cardiomyocyte apoptosis, which were attenuated by co-transfection with miR-19a mimic. Dual-luciferase reporter assay and Western blotting assay revealed that PTEN was a direct target gene of miR-19a, and miR-19a suppressed the expression of PTEN via binding to its 3′-UTR. We further identified that overexpression of miR-19a inhibited the expression of PTEN at the mRNA and protein levels. Moreover, PTEN was highly expressed in H/R H9C2 cells and the apoptosis induced by H/R was associated with the increase in PTEN expression. Importantly, miR-19a mimic significantly increased p-Akt levels under H/R. In conclusion, our findings indicate that miR-19a could protect against H/R-induced cardiomyocyte apoptosis by inhibiting PTEN /PI3K/p-Akt signaling pathway.

Effect of picroside II on hind limb ischemia reperfusion injury in rats

Introduction

Many structural and functional damages are observed in cells and tissues after reperfusion of previously viable ischemic tissues. Acute ischemia reperfusion (I/R) injury of lower extremities occurs especially when a temporary cross-clamp is applied to the abdominal aorta during aortic surgery. Research regarding the treatment of I/R injury has been increasing day-by-day. In this study, we aimed to investigate the effect of picroside II on skeletal muscle of rats experiencing simulated I/R.

Materials and methods

Twenty-four male Wistar albino rats weighing between 210 and 300 g were used in this study. Rats were randomly divided into 4 groups of 6 rats each (control, I/R, control + picroside II, and I/R + picroside II). The infrarenal section of the abdominal aorta was occluded with an atraumatic microvascular clamp in I/R group. The clamp was removed after 120 minutes and reperfusion was provided for a further 120 minutes. Picroside II (10 mg kg⁻¹) was administered intraperitoneally to the animals in control + picroside II and I/R + picroside II groups. At the end of the study, skeletal muscle tissue was obtained for the determination of total oxidant status (TOS) and total antioxidant status (TAS) levels. Apoptosis was evaluated by TUNEL experiment.

Results

TOS levels were significantly higher in I/R group than that of control and I/R + picroside II groups (P=0.014, P=0.005, respectively). TAS levels were significantly higher in I/R group than that of control and I/R + picroside II groups (P=0.007 P=0.005, respectively). TUNEL assay revealed that picroside II reduced cell necrosis.

Conclusion

The results of this study demonstrated that picroside II plays a critical role to prevent I/R injury. Even though our results were found to be satisfactory, it should be encouraging to those who want to conduct future research on this topic.

Modular Design of Picroside-II Biosynthesis Deciphered through NGS Transcriptomes and Metabolic Intermediates Analysis in Naturally Variant Chemotypes of a Medicinal Herb, Picrorhiza kurroa

Picroside-II (P-II), an iridoid glycoside, is used as an active ingredient of various commercial herbal formulations available for the treatment of liver ailments. Despite this, the knowledge of P-II biosynthesis remains scarce owing to its negligence in Picrorhiza kurroa shoots which sets constant barrier for function validation experiments. In this study, we utilized natural variation for P-II content in stolon tissues of different P. kurroa accessions and deciphered its metabolic route by integrating metabolomics of intermediates with differential NGS transcriptomes. Upon navigating through high vs. low P-II content accessions (1.3-2.6%), we have established that P-II is biosynthesized via degradation of ferulic acid (FA) to produce vanillic acid (VA) which acts as its immediate biosynthetic precursor. Moreover, the FA treatment in vitro at 150 μM concentration provided further confirmation with 2-fold rise in VA content. Interestingly, the cross-talk between different compartments of P. kurroa, i.e., shoots and stolons, resolved spatial complexity of P-II biosynthesis and consequently speculated the burgeoning necessity to bridge gap between VA and P-II production in P. kurroa shoots. This work thus, offers a forward looking strategy to produce both P-I and P-II in shoot cultures, a step toward providing a sustainable production platform for these medicinal compounds via-à-vis relieving pressure from natural habitat of P. kurroa.

Ghrelin protected neonatal rat cardiomyocyte against hypoxia/reoxygenation injury by inhibiting apoptosis through Akt-mTOR signal

Reducing reperfusion period myocardial cell damage is efficient to reduce myocardial ischemia-reperfusion injury. Ghrelin can increase myocardial contractility, improve heart failure caused by myocardial infarction. This study aimed to investigate the protective effect of Ghrelin on myocardial hypoxia/reoxygenation (H/R) injury of neonatal rat cardiomyocytes (NRCMs) and to explore the mechanisms. We isolated the NRCMs, established myocardial H/R model, blocked growth hormone secretagogue receptor (GHSR) by siRNA technique, examined cell activity by MTT and LDH assay, detected apoptosis by Hoechst 33258 staining and flow cytometry and determined the expression levels of apoptosis related proteins and signaling pathway proteins by western blot. We found that Ghrelin can significantly improve cell activity and decrease apoptosis after H/R, however this effect was abolished by GHSR-siRNA. In addition, we found that Ghrelin can significantly increase the expression of Bcl-2 but inhibit the level of Bax and caspase-3. Further mechanism study found that the phosphorylation level of signaling pathway protein Akt and mTOR in Ghrelin treated group were significantly higher than that in other groups. In conclusion, Ghrelin can reduce the H/R damage on NRCMs and inhibit the apoptosis by activating Akt-mTOR signaling pathway.

3'-Daidzein sulfonate sodium improves mitochondrial functions after cerebral ischemia/reperfusion injury

3′-Daidzein sulfonate sodium is a new synthetic water-soluble compound derived from daidzein (an active ingredient of the kudzu vine root). It has been shown to have a protective effect on cerebral ischemia/reperfusion injury in rats. We plan to study the mechanism of its protective effect. 3′-Daidzein sulfonate sodium was injected in rats after cerebral ischemia/reperfusion injury. Results showed that 3′-daidzein sulfonate sodium significantly reduced mitochondrial swelling, significantly elevated the mitochondrial membrane potential, increased mitochondrial superoxide dismutase and glutathione peroxidase activities, and decreased mitochondrial malondialdehyde levels. 3′-Daidzein sulfonate sodium improved the structural integrity of the blood-brain barrier and reduced blood-brain barrier permeability. These findings confirmed that 3′-daidzein sulfonate sodium has a protective effect on mitochondrial functions after cerebral ischemia/reperfusion injury, improves brain energy metabolism, and provides protection against blood-brain barrier damage.

Neuroprotective effect of picroside II in brain injury in mice

Various types of brain injury which led to the damage of brain tissue structure and neurological dysfunction continues to be the major causes of disability and mortality. Picroside II (PII) possesses a wide range of pharmacological effects and has been proved to ameliorate ischemia and reperfusion injury of kidney and brain. However, critical questions remain about other brain injuries. We investigated the protective effect of PII in four well-characterized murine models of brain injury. Models showed a subsequent regional inflammatory response and oxidative stress in common, which might be improved by the administration of PII (20 mg/kg). Meanwhile, a series of morphological and histological analyses for reinforcement was performed. In traumatic, ischemic and infectious induced injuries, it was observed that the survival rate, apoptosis related proteins, Caspase-3, and the expression of acute inflammatory cytokines (IL-1β, IL-6 and TNF-α) were significantly alleviated after PII injection, but PII treatment alone showed no effect on them as well. The western blot results indicated that TLR4 and NF-κB were clearly downregulated with PII administration. In conclusion, our results suggested that PII with a recommended concentration of 20 mg/kg could provide neuroprotective effects against multi-cerebral injuries in mice by suppressing the over-reactive inflammatory responses and oxidative stress and attenuating the damage of brain tissue for further neurological recovery.

Characterization of picroside II metabolites in rats by ultra-high-performance liquid chromatography combined with electrospray ionization quadrupole time-of-flight tandem mass spectrometry

Picroside II, a bioactive compound isolated from Picrorhiza scrophulariiflora Pennell, has been reported to have hepatoprotective, neuroprotective, and antioxidant effects. However, the detailed in vivo biotransformation of this compound has been rarely reported. This study aimed to investigate the metabolic profiles of picroside II in rats by using ultra-high-performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry. Metabolite structures were elucidated based on accurate mass measurements of deprotonated molecules and their fragmentation patterns. Thirteen metabolites were structurally identified, and the detailed metabolic pathways were proposed. The findings revealed that after oral administration, picroside II mainly undergoes four metabolic pathways. In the first pathway, picroside II is deglycosylated to generate aglycone, which is isomerized to a dialdehyde-type intermediate. A series of metabolic reactions, including glucuronidation, subsequently occurs. In the second pathway, picroside II is subjected to ester bond hydrolysis to form vanillic acid, which is further subjected to sulfate conjugation, glycine conjugation, glucuronidation, and demethylation. In the third pathway, picroside II is directly conjugated with glucuronic acid to yield a predominant metabolite (M01) in plasma. In the fourth pathway, picroside II is directly conjugated with sulfate. These findings provide insights into the in vivo disposition of picroside II and are useful to understand the mechanism of effectiveness and toxicity of this compound as well as P. scrophulariiflora-related preparations.

A novel voltammetric sensor based on poly(l-Citrulline)/SWCNTs composite film modified electrode for sensitive determination of picroside II

A novel voltammetric sensor was constructed by simple dripping single-walled carbon nanotubes (SWCNTs) on to the glass carbon electrode (GCE) firstly and electro-polymerizing L-Citrulline film subsequently. The resulting poly(L-Citrulline)/SWCNTs/GCE showed a significant voltammetric response to picroside II due to the synergistic effect of SWCNTs and poly(L-Citrulline) film. The first electroanalytical method of picroside II was proposed with detection linear range from 8.0 × 10(-8) to 5.0 × 10(-6) mol L(-1) and a detection limit of 3 × 10(-8) mol L(-1). The high sensitivity, selectivity and long-term stability made the sensor suitable for the determination of picroside II. Moreover, based on the systematically investigation and some kinetics parameters calculated in the experimentation, the reaction mechanism of picroside II at the poly(L-Citrulline)/SWCNTs modified GCE was obtained reliably. Lastly, the proposed sensor was used for the determination of picroside II in real sample with satisfactory results. This work promoted the potential applications of amino acid materials and SWCNTs in electro-chemical sensors.

Effect of picroside II on erythrocyte deformability and lipid peroxidation in rats subjected to hind limb ischemia reperfusion injury

Background

Ischemia reperfusion injury (I/R) in hind limb is a frequent and important clinical phenomenon. Many structural and functional damages are observed in cells and tissues in these kinds of injuries. In this study, we aimed to evaluate the effect of picroside II on lipid peroxidation and erythrocyte deformability during I/R in rats.

Methods

Rats were randomly divided into four groups – each containing six animals (sham, I/R, sham + picroside II, and I/R + picroside II). The infrarenal section of the abdominal aorta was occluded with an atraumatic microvascular clamp in I/R groups. The clamp was removed after 120 minutes and reperfusion was provided for a further 120 minutes. Picroside II (10 mg·kg⁻¹) was administered intraperitoneally to the animals in the appropriate groups (sham + picroside II, I/R + picroside II groups). All rats were euthanized by intraperitoneal administration of ketamine (100 mg·kg⁻¹) and taking blood from the abdominal aorta. Erythrocytes were extracted from heparinized complete blood samples. Buffer (P_T) and then erythrocytes (P_E) were passed through the filtration system and the changes in pressure were measured to investigate the role of serum malondialdehyde and nitric oxide (NO) in lipid peroxidation and erythrocyte deformability index.

Results

Deformability index was significantly increased in the I/R group compared to groups sham, sham + picroside-II, and I/R + picroside-II (P<0.0001, P<0.0001, and P=0.007). Malondialdehyde (MDA) and NO levels were evaluated. MDA level and NO activity were also higher in the I/R group than in the other groups. Picroside II treatment before hind limb I/R prevented these changes.

Conclusion

These results support that deformability of erythrocytes is decreased in I/R injury and picroside II plays a critical role to prevent these alterations. Further experimental and clinical studies are needed to evaluate and clarify the molecular mechanisms of action and clinical importance of these findings.

Picroside II has a neuroprotective effect by inhibiting ERK1/2 activation after cerebral ischemic injury in rats

In the study, the neuroprotective effect and underlying mechanism of picroside II were explored, and its involvement in the ERK1/2 signal pathway after cerebral ischemia injury in rats. A monofilament thread was inserted to generate middle cerebral artery occlusion (MCAO) in 100 Wistar rats that were administered an intraperitoneal injection of picroside II (20 mg/kg). The neurobehavioural function of rats was evaluated using a modified neurological severity score (mNSS) test. The cerebral infarct volume (CIV) was measured using tetrazolium chloride (TTC) staining. The morphology and ultra-structure of the nerve cells in the cortex were observed using hematoxylin and eosin (HE) staining and transmission electron microscopy (TEM), respectively. The apoptotic cells were counted using the terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay. The expression of extracellular signal-regulated kinase 1/2 (pERK1/2) in the cortex was determined using immunohistochemistry and Western blot analysis. Neurological dysfunction was observed in all rats with MCAO. In both the model and lipopolysaccharide (LPS) groups, the CIV increased, the neuronal damage in the cortex was more severe, and the number of apoptotic cells and the pERK1/2 expression significantly increased compared with the control group (P < 0.05). In treatment and U0126 groups, the neurological function was improved, the CIV decreased, the neuronal damage in the cortex was attenuated, and the number of apoptotic cells and the pERK1/2 expression significantly decreased compared with the model group (P < 0.05). No significant differences in these indices were observed between model and LPS groups or treatment and U0126 groups (P > 0.05). The results suggest that activation of ERK1/2 in cerebral ischaemia induces neuronal apoptosis and picroside II may reduce neuronal apoptosis to confer protection against cerebral ischemic injury by inhibiting ERK1/2 activation.

Picroside II Inhibits the MEK-ERK1/2-COX2 Signal Pathway to Prevent Cerebral Ischemic Injury in Rats

The objective of this study is to explore the neuroprotective effect and mechanism of picroside II on ERK1/2-COX2 signal transduction pathway after cerebral ischemic injury in rats. Focal cerebral ischemic models were established by inserting monofilament threads into the middle cerebral artery in 200 Wistar rats. Twenty four rats were randomly selected into control group, while the other rats were randomly divided into six groups: model group, picroside group, lipopolysaccharide (LPS) with picroside group, U0126 with picroside group, LPS group, and U0126 group with each group containing three subgroups with ischemia at 6, 12, and 24 h. Neurobehavioral function in the rats was evaluated by modified neurological severity score points (mNSS) test; structure of neurons was observed using hematoxylin-eosin (HE) staining; apoptotic cells were counted using terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay; expressions of phosphorylated mitogen/extracellular signal-regulated kinase kinas1/2 (pMEK1/2), phosphorylated extracellular signal-regulated protein kinase1/2 (pERK1/2), and cyclooxygenase (COX2) in the cortex were determined using immunohistochemistry (IHC) and Western blot (WB); and real-time PCR was used to determine the level of COX2 mRNA. The neurological behavioral malfunction appeared in all rats with middle cerebral artery occlusion (MCAO). In the model group, neuron damage was extensive, while the neurobehavioral function score, apoptotic cell index, expression of pMEK1/2, pERK1/2, and COX2 and the level of COX2 mRNA increased significantly when compared to the control group. The peak COX2 mRNA level was in ischemia 12 h, prior to the peak in COX2 protein expression. In the picroside and U0126 groups, the neurological behavioral function was improved, and the number of apoptotic cells and the expression of pMEK1/2, pERK1/2, and COX2 decreased significantly when compared to the model group. In the LPS with picroside group, at ischemia 6 h neuron damage was extensive, and pMEK1/2, pERK1/2, and COX2 expression were much higher than in the model group. But at ischemia 12 and 24 h, the expression of pMEK1/2, pERK1/2, and COX2 decreased slightly, and the neurobehavioral function also improved slightly. In LPS group, neuron damage was extensive, pMEK1/2, pERK1/2, and COX2 expression was still at a high level, and COX2 mRNA peak arrived at ischemic 12 h. Picroside II downregulates COX2 expression after MCAO by inhibiting MEK-ERK1/2 in rats to protect neurons from apoptosis and inflammation.

Piscroside C, a novel iridoid glycoside isolated from Pseudolysimachion rotundum var. subinegrum suppresses airway inflammation induced by cigarette smoke

ETHNOPHARMACOLOGICAL RELEVANCE

Pseudolysimachion rotundum var. subintegrum (Speedwell, Plantaginaceae) is used as a traditional herbal medicine for treating bronchitis, cough and asthma in Korea, China, Russia, and Europe.

AIM OF THE STUDY

In this study, we investigated the protective effects of the novel iridoid glycoside, piscroside C (compound 1) isolated from the methanolic extract of P. rotundum var. subintegrum against inflammatory responses using a cigarette smoke induced chronic obstructive pulmonary disease (COPD) and TNF-α-stimulated human airway epithelial NCI-H292 cells.

MATERIALS AND METHODS

The novel iridoid glycoside piscroside C was isolated from the methanolic extract of P. rotundum var. subintegrum. The chemical structure was established by NMR, HRESIMS, and optical rotation. In in vivo experiment, the mice received 1h of cigarette smoke for 3 days. Piscroside C was administered to mice by oral gavage 1h before cigarette smoke exposure for 3 days. In in vitro experiment, we evaluated the effect of piscroside C on proinflammatory mediators in H292 cells stimulated with TNF-α.

RESULTS

Piscroside C significantly reduced the neutrophil influx, reactive oxygen species production, IL-6, TNF-α, and elastase activity in bronchoalveolar lavage fluid in COPD animals. In addition, piscroside C attenuated NF-κB and IκB phosphorylation, leading to reduced recruitment of inflammatory cells into the lung tissue. Consistent with the results of in vivo experiment, piscroside C significantly inhibited the expression of inflammatory cytokines (IL-6, IL-8 and IL-1β) by inhibiting NF-κB activation, as resulting decrease in the phosphorylation of IKKβ, IκBα and TAK1 in TNF-α-stimulated H292 cells.

CONCLUSION

These findings indicate that piscroside C effectively inhibits inflammatory responses, which is an important process in the development of COPD through suppression of IKK/NF-κB activation. Our study suggest that piscroside C might represent a useful therapeutic for the treatment of inflammatory airway disease.

Picroside II decreases the development of fibrosis induced by ischemia/reperfusion injury in rats

In kidney transplantation, renal ischemia and reperfusion injury was one of the leading factors to the development of renal fibrosis, which was the main cause of graft loss. The fibrogenic changes were associated with the long term inflammation elicited by ischemia and reperfusion injury. In the present study, we investigated the role of the Picroside II, the main active constituents of the extract of picrorrhiza scrophulariiflora roots, in attenuating renal fibrosis in a renal ischemia and reperfusion injury model. We induced ischemia and reperfusion injury in kidneys treated with or without Picroside II. We observed that inflammation and tissue fibrosis were increased in ischemia and reperfusion injury group compared to Picroside II group, however, these changes were significantly decreased by the treatment with Picroside II. We concluded that Picroside II can protect the ischemic kidney against renal fibrosis and its mechanism may be through the inhibition of the long term inflammation.

Picroside II Inhibits Neuronal Apoptosis and Improves the Morphology and Structure of Brain Tissue following Cerebral Ischemic Injury in Rats

This paper aimed to explore the protective effects of picroside II against the neuronal apoptosis and changes in morphology and structure that follow cerebral ischemic injury in rats. A focal cerebral ischemic model was established by inserting a monofilament thread to achieve middle cerebral artery occlusion (MCAO) in 60 Wistar rats, and intraperitoneal injections of picroside II (20 mg/kg) were administered. The neurobehavioral functions were evaluated with the modified neurological severity score (mNSS) test. The cerebral infarct volumes were measured with tetrazolium chloride (TTC) staining. The morphology and ultrastructure of the cortical brain tissues were observed with hematoxylin-eosin staining and transmission electron microscopy, respectively. The apoptotic cells were counted with terminal deoxynucleotidyl transferase dUTP nick-end labeling and flow cytometry, and pERK1/2 expression was determined by immunohistochemical assay and Western blot. The results indicated that neurological behavioral malfunctions and cerebral infarcts were present in the MCAO rats. In the model group, the damage to the structures of the neurons and the blood brain barrier (BBB) in the cortex was more severe, and the numbers of apoptotic cells, the early apoptotic ratio (EAR) and pERK1/2 expression were significantly increased in this group compared to the control group (P<0.05). In the treatment group, the neurological behavioral function and the morphology and ultrastructure of the neurons and the BBB were improved including the number of Mi increased and relative area of condensed chromosome and basement (BM) thickness descreased, and the cerebral infarct volume, the number of apoptotic cells, the EAR and pERK1/2 expression were significantly decreased compared to the model group (P<0.05). These results suggest that picroside II reduced apoptosis and improved the morphology and ultrastructure of the neurons and the BBB and that these effects resulted in the recovery of the neurobehavioral function of rats with cerebral ischemia.

Picroside II protects rat kidney against ischemia/reperfusion-induced oxidative stress and inflammation by the TLR4/NF-κB pathway

Picroside II possesses a wide range of pharmacological effects and has been demonstrated to ameliorate cerebral ischemia and reperfusion (I/R) injury. However, its effects on renal I/R injury remain unclear. In the present study, the role of picroside II in attenuating oxidative stress and the inflammatory response in a rat model of renal I/R injury was investigated. Sprague Dawley rats were subjected to 45 min of ischemia followed by 24 h of reperfusion. Prior to reperfusion, the rats were treated with picroside II or an equal volume of phosphate-buffered saline. Renal function and histological changes were compared and the relevant parameters of oxidative stress and inflammation were detected. The expression of toll-like receptor 4 (TLR4) and nuclear factor κB (NF-κB; p65) were assessed by immunohistochemistry and western blotting. It was observed that renal function was significantly improved by treatment with picroside II. Morphological analysis indicated that picroside II clearly reduced tissue damage and the expression of TLR4 and NF-κB. Reverse transcription-quantitative polymerase chain reaction demonstrated that picroside II inhibited the increase of tumor necrosis factor (TNF)-α, interleukin (IL)-1β and intercellular adhesion molecule (ICAM)-1 expression induced by I/R injury. Western blot analysis indicated that the expression levels of TLR4 and NF-κB were significantly downregulated in the picroside II group compared with those in the I/R group. These results indicate that picroside II treatment suppressed the TLR4/NF-κB signaling pathway, protecting renal tissue against I/R-induced oxidative stress and inflammatory response.

Effect of picroside II on apoptosis induced by renal ischemia/reperfusion injury in rats

Renal ischemia and reperfusion (I/R) injury, which commonly occurs in kidney transplantation, is the leading cause of acute kidney injury. Picroside II possesses a wide range of pharmacological effects, including anti-apoptosis effects. In the present study, the ability of picroside II to attenuate apoptosis in a rat model of renal I/R injury was investigated. Sprague-Dawley rats were subjected to 45 min of ischemia followed by 24 h of reperfusion. Prior to reperfusion, the rats were treated with picroside II or an equal volume of phosphate-buffered saline. It was observed that renal function was significantly improved by the treatment with picroside II. Morphological analysis indicated that picroside II markedly reduced tissue damage and the expression of cleaved caspase-3. Reverse transcription-quantitative polymerase chain reaction and western blotting revealed that the expression levels of Bax and poly(ADP-ribose) polymerase-1 (PARP-1) were upregulated in the I/R group, whereas those of Bcl-2 were downregulated. However, the treatment with picroside II inhibited these changes induced by renal I/R injury. In conclusion, picroside II has potent anti-apoptotic activity against renal I/R injury.

Optimal therapeutic dose and time window of picroside II in cerebral ischemic injury

A preliminary study from our research group showed that picroside II inhibited neuronal apoptosis in ischemic penumbra, reduced ischemic volume, and improved neurobehavioral function in rats with cerebral ischemia. The aim of the present study was to validate the neuroprotective effects of picroside II and optimize its therapeutic time window and dose in a rat model of cerebral ischemia. We found that picroside II inhibited cell apoptosis and reduced the expression of neuron-specific enolase, a marker of neuronal damage, in rats after cerebral ischemic injury. The optimal treatment time after ischemic injury and dose were determined, respectively, as follows: (1) 2.0 hours and 10 mg/kg according to the results of toluidine blue staining; (2) 1.5 hours and 10 mg/kg according to early apoptotic ratio by flow cytometry; (3) 2.0 hours and 10 mg/kg according to immunohistochemical and western blot analysis; and (4) 1.5 hours and 10 mg/kg according to reverse transcription polymerase chain reaction. The present findings suggest that an intraperitoneal injection of 10 mg/kg picroside II 1.5-2.0 hours after cerebral ischemic injury in rats is the optimal dose and time for therapeutic benefit.

Neuroprotective effects of rutaecarpine on cerebral ischemia reperfusion injury

Rutaecarpine, an active component of the traditional Chinese medicine Tetradium ruticarpum, has been shown to improve myocardial ischemia reperfusion injury. Because both cardiovascular and cerebrovascular diseases are forms of ischemic vascular disease, they are closely related. We hypothesized that rutaecarpine also has neuroprotective effects on cerebral ischemia reperfusion injury. A cerebral ischemia reperfusion model was established after 84, 252 and 504 μg/kg carpine were given to mice via intraperitoneal injection, daily for 7 days. Results of the step through test, 2,3,5-triphenyl tetrazolium chloride dyeing and oxidative stress indicators showed that rutaecarpine could improve learning and memory ability, neurological symptoms and reduce infarction volume and cerebral water content in mice with cerebral ischemia reperfusion injury. Rutaecarpine could significantly decrease the malondialdehyde content and increase the activities of superoxide dismutase and glutathione peroxidase in mouse brain. Therefore, rutaecarpine could improve neurological function following injury induced by cerebral ischemia reperfusion, and the mechanism of this improvement may be associated with oxidative stress. These results verify that rutaecarpine has neuroprotective effects on cerebral ischemia reperfusion in mice.

Protective effect of picroside II on myocardial ischemia reperfusion injury in rats

The aim of this study was to determine the effect of picroside II on myocardial ischemia reperfusion injury in rats and to explore its underlying mechanism. Isolated rat hearts underwent 30 minutes of global ischemia followed by 120 minutes of reperfusion. Different doses of picroside II (1 μM, 10 μM, and 100 μM) were given 20 minutes before ischemia. Phosphoinositide 3-kinase inhibitor (wortmannin) and nitric oxide synthase (NOS) inhibitor (L-N(G)-nitroarginine methyl ester) were given 10 minutes before picroside II treatment. The cardiac function, myocardial infarct size, apoptosis, myocardial nitric oxide content, the expressions of Bcl-2 and Bax, and the activation of the phosphoinositide 3-kinase/Akt/endothelial NOS pathway were evaluated. Treatment with 10 μM and 100 μM picroside II significantly improved postischemic myocardial function, reduced myocardial infarct size, inhibited apoptosis, increased myocardial NO content, upregulated Bcl-2, downregulated Bax, and increased the phosphorylation of Akt and endothelial NOS, but cardioprotection was not shown in the 1 μM picroside II treatment group and was abrogated by wortmannin and L-N(G)-nitroarginine methyl ester. Furthermore, cardioprotection in the 100 μM picroside II treatment group was superior to that in the 10 μM picroside II treatment group. In conclusion, the data reveals that picroside II has a significant protective effect on myocardial ischemia reperfusion injury in a dose-dependent manner, which was mediated by upregulating the phosphoinositide 3-kinase/Akt/endothelial NOS pathway to increase nitric oxide production and regulating the expressions of Bcl-2 and Bax to inhibit apoptosis.

The neuroprotective effect of picroside II via regulating the expression of myelin basic protein after cerebral ischemia injury in rats

Background

To explore the neuroprotective effect and optimize the therapeutic dose and time window of picroside II by orthogonal test and the expression of myelin basic protein (MBP) in cerebral ischemic injury in rats. Bilateral common carotid artery occlusion (BCCAO) was used to establish forebrain ischemia models. The successful rat models were grouped according to orthogonal experimental design and injected picroside II intraperitoneally at different ischemic time with different doses. Myelin sheath fast green staining(FGS) and transmission electron microscopy (TEM) were used to observe nerve fiber myelin; the expression of MBP was tested qualitatively and quantitatively by immunohistochemical assay (IHC) and Western blot (WB); Reverse transcription polymerase chain reaction (RT-PCR) was used to detect the transcription level of MBP mRNA.

Results

The protective effect of picroside II was presented by increasing the expression of MBP and decreasing demyelination after cerebral ischemic injury. The best therapeutic time window and dose was (1) ischemia 2.0 h with picroside II 10 mg/kg body weight according to the results of FGS, IHC and WB; (2) ischemia 1.5 h with picroside II 20 mg/kg according to the analysis of RT-PCR.

Conclusion

Given the principle of the longest time window and the lowest therapeutic dose, the optimized therapeutic dose and time window should be injecting picroside II intraperitoneally with 10-20 mg/kg body weight at ischemia 1.5-2.0 h in cerebral ischemic injury.

Astragalus injection protects cerebral ischemic injury by inhibiting neuronal apoptosis and the expression of JNK3 after cerebral ischemia reperfusion in rats

BACKGROUND

Astragalus is a widely used traditional Chinese medicine and has been proven beneficial for many aspects of human health. It is important to explore the neuroprotective effect and mechanism of astragalus injection in cerebral ischemia reperfusion injury.

METHODS

The focal cerebral ischemic model with middle cerebral artery occlusion (MCAO) reperfusion was established by Longa's method in healthy adult male Wistar rats, and treated by injecting intraperitoneally astragalus injection (3 ml/kg). The neurobehavioral function of rats was evaluated by Longa's test. The cerebral blood flow (CBF) was measured by laser Doppler flowmetry and the cerebral infarct volume was calculated by tetrazolium chloride (TTC) stain. The shape and structure of neurons in parahippocampal area was observed by HE stain and the neuronal apoptosis was detected by terminal deoxynucleotidyl transferase mediated dUTP nick end labeling (TUNEL) and flow cytometry. The expressions of c-jun N-terminal kinase 3 (JNK3) mRNA and protein were determined by RT-PCR and immunohistochemical assay and Western blotting respectively.

RESULTS

After treatment with astragalus injection, the expressions of JNK3 mRNA and protein reduced significantly, the number of neuronal apoptosis minus, the cerebral infarct volume shrink, the neuronal shape-structure and animal neurobehavioral function improved significantly than those in model rats.

CONCLUSIONS

It is suggested that astragalus injection could inhibit neuronal apoptosis, reduce infarct volume and improve neurobehavioral function by down-regulating the expression of JNK3 gene after cerebral ischemia reperfusion injury in rats.

Method parameters' impact on mortality and variability in rat stroke experiments: a meta-analysis

Background

Even though more than 600 stroke treatments have been shown effective in preclinical studies, clinically proven treatment alternatives for cerebral infarction remain scarce. Amongst the reasons for the discrepancy may be methodological shortcomings, such as high mortality and outcome variability, in the preclinical studies. A common approach in animal stroke experiments is that A) focal cerebral ischemia is inflicted, B) some type of treatment is administered and C) the infarct sizes are assessed. However, within this paradigm, the researcher has to make numerous methodological decisions, including choosing rat strain and type of surgical procedure. Even though a few studies have attempted to address the questions experimentally, a lack of consensus regarding the optimal methodology remains.

Methods

We therefore meta-analyzed data from 502 control groups described in 346 articles to find out how rat strain, procedure for causing focal cerebral ischemia and the type of filament coating affected mortality and infarct size variability.

Results

The Wistar strain and intraluminal filament procedure using a silicone coated filament was found optimal in lowering infarct size variability. The direct and endothelin methods rendered lower mortality rate, whereas the embolus method increased it compared to the filament method.

Conclusions

The current article provides means for researchers to adjust their middle cerebral artery occlusion (MCAo) protocols to minimize infarct size variability and mortality.

The protective effect of picroside II against hypoxia/reoxygenation injury in neonatal rat cardiomyocytes

CONTEXT

Picroside II, an iridoid glucoside found in the root of Picrorhiza scrophulariiflora Pennell (Scrophulariaceae), has been demonstrated to possess potent antioxidant activity. However, whether picroside II has a protective effect against hypoxia/reoxygenation (H/R)-induced cardiomyocyte injury is poorly understood.

OBJECTIVE

To explore the cardioprotective role of picroside II against oxidative stress induced by H/R injury in neonatal rat cardiacmyocytes.

MATERIALS AND METHODS

The viability and cellular damage of cardiomyocytes were assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolim bromide (MTT) and lactate dehydrogenase (LDH) assays, respectively. The activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), the levels of reduced (GSH) and oxidized glutathione (GSSG), and the contents of malondialdehyde (MDA) were determined by a colorimetric method. The levels of intracellular reactive oxygen species (ROS) and calcium were evaluated by flow cytometric analysis.

RESULTS

We analyzed the effective half-maximal concentration for protection from the dose-response curves and obtained the concentration of 50 µg/mL as EC(50). Pretreated cardiomyocytes with picroside II (50-200 µg/mL), prior to H/R exposure, inhibited LDH activity in culture media and increased cell viability in a dose-dependent manner. This protective effect was accompanied by significantly increasing reduced GSH contents and the activities of SOD and GSH-Px and attenuating MDA and GSSG contents in response to H/R injury. Furthermore, treatment with picroside II also inhibited ROS production and calcium accumulation in cardiomyocytes.

DISCUSSION AND CONCLUSION

The present study demonstrates that picroside II protects cardiomyocytes against oxidative-stress injury induced by H/R through reduction of ROS production and calcium accumulation and enhancement of the activity of antioxidant defense.

Formulas used by Tibetan doctors at Men-Tsee-Khang in India for the treatment of neuropsychiatric disorders and their correlation with pharmacological data

The aim of the present study was to identify formulas used at Men-Tsee-Khang (Tibetan Medical and Astrological Institute), India, for the treatment of neuropsychiatric disorders and to compare the Tibetan usage of particular ingredients with pharmacological data from the scientific database. Using ethnographic methods, five doctors were selected and interviewed. A correlation was observed between central nervous system disorders and rLung, one of the three humors in Tibetan medicine, which imbalance is the source of mental disorders, and ten multi-ingredient formulas used to treat the imbalance of this particular humor were identified. These formulas utilize 61 ingredients; among them were 48 plant species. Each formula treats several symptoms related to rLung imbalance, so the plants may have therapeutic uses distinct from those of the formulas in which they are included. Myristica fragrans, nutmeg, is contained in 100% of the formulas, and its seeds exhibit stimulant and depressant actions affecting the central nervous system. Preclinical and clinical data from the scientific literature indicate that all of the formulas include ingredients with neuropsychiatric action and corroborate the therapeutic use of 75.6% of the plants. These findings indicate a level of congruence between the therapeutic uses of particular plant species in Tibetan and Western medicines.

Primary study for the therapeutic dose and time window of picroside II in treating cerebral ischemic injury in rats

The aim of this study was to explore the optimal therapeutic dose and time window of picroside II for treating cerebral ischemic injury in rats according to the orthogonal test. The middle cerebral artery occlusion (MCAO) models were established by intraluminally inserting a thread into middle cerebral artery (MCA) from left external carotid artery (ECA). The successful rat models were randomly divided into 16 groups according to the orthogonal layout of [L₁₆(4⁵)] and treated by injecting picroside II intraperitoneally with different doses at various times. The neurological behavioral function was evaluated by Bederson’s test and the cerebral infarction volume was measured by tetrazolium chloride (TTC) staining. The expressions of neuron specific enolase (NSE) and neuroglial mark-protein S-100 were determined by immunohistochemisty assay. The results indicated that the optimal compositions of the therapeutic dose and time window of picroside II in treating cerebral ischemic injury were ischemia 1.5 h with 20 mg/kg body weight according to Bederson’s test, 1.0 h with 20 mg/kg body weight according to cerebral infarction volume, 1.5 h with 20 mg/kg body weight according to the expressions of NSE and S-100 respectively. Based on the principle of the minimization of medication dose and maximization of therapeutic time window, the optimal composition of the therapeutic dose and time window of picroside II in treating cerebral ischemic injury should be achieved by injecting picroside II intraperitoneally with 20 mg/kg body weight at ischemia 1.5 h.

Neuroprotective effects of total saponins from Rubus parvifolius L. on cerebral ischemia/reperfusion injury in rats

This study examines the neuroprotective effects and mechanisms of action of total saponins from Rubus parvifolius L. (TSRP) on focal cerebral ischemia and reperfusion injury in rats. Focal cerebral ischemia and reperfusion injury was performed in rats using the suture method. The results indicate that intragastric injection of TSRP, at 5, 10 and 20 mg/kg, could decrease neurological impairment, reduce cerebral infarct volume, diminish pathological changes, and significantly inhibit the apoptosis of neurons surrounding the ischemic area. In addition, TSRP upregulated the expression of the anti-apoptotic factor Bcl-2, at the protein and mRNA levels, and it downregulated the expression of the pro-apoptotic factor Bax, at the protein and mRNA levels. These findings indicate that TSRP protects against cerebral ischemia/reperfusion injury, and that it may do so by regulating the expression of Bcl-2 and Bax.