Effect of ligustrazine on ischemia-reperfusion injury in murine kidney

Research progress of astragaloside IV in treating acute kidney injury

Acute kidney injury (AKI) is one of the most common clinical critical illnesses, with decreased glomerular filtration rate, retention of nitrogen products, water and electrolyte disorders, and acid-base imbalance as the main clinical manifestations. Presently, there is no effective treatment for acute kidney injury, but the main treatment is to cure the primary disease, remove risk factors, maintain acid-base and water-electrolyte balance, and undergo kidney replacement. However, the mortality rate is still high. Investigations and studies showed that the mortality rate of patients with acute kidney injury in the ICU is 5-80% [1]. In recent years, Chinese medicine has been widely used in acute kidney injury treatment due to its complete dialectical system and rich experience. Astragalus is a commonly used medicine in traditional Chinese medicine to treat acute kidney injury. Astragaloside IV is the main active component of traditional Chinese medicine, Astragalus membranaceus. This article summarizes the relevant studies on treating acute kidney injury with astragaloside IV.

Bibliometric analysis of research progress on tetramethylpyrazine and its effects on ischemia-reperfusion injury

In recent decades, natural products have attracted worldwide attention and become one of the most important resources for pharmacological industries and medical sciences to identify novel drug candidates for disease treatment. Tetramethylpyrazine (TMP) is an alkaloid extracted from Ligusticum chuanxiong Hort., which has shown great therapeutic potential in cardiovascular and cerebrovascular diseases, liver and renal injury, as well as cancer. In this review, we analyzed 1270 papers published on the Web of Science Core Collection from 2002 to 2022 and found that TMP exerted significant protective effects on ischemia-reperfusion (I/R) injury that is the cause of pathological damages in a variety of conditions, such as ischemic stroke, myocardial infarction, acute kidney injury, and liver transplantation. TMP is limited in clinical applications to some extent due to its rapid metabolism, a short biological half-life and poor bioavailability. Obviously, the structural modification, administration methods and dosage forms of TMP need to be further investigated in order to improve its bioavailability. This review summarizes the clinical applications of TMP, elucidates its potential mechanisms in protecting I/R injury, provides strategies to improve bioavailability, which presents a comprehensive understanding of the important compound. Hopefully, the information and knowledge from this review can help researchers and physicians to better improve the applications of TMP in the clinic.

Protective effects of sitagliptin on methotrexate-induced nephrotoxicity in rats

Methotrexate (MTX), a cytotoxic chemotherapeutic and immunosuppressant agent, is widely used in the treatment of autoimmune diseases and different types of cancers. However, its use has been limited by its life-threatening side effects, including nephrotoxicity and hepatotoxicity. The purpose of this study was to investigate the protective effect of sitagliptin on methotrexate (MTX)-induced nephrotoxicity in rats. Twenty-four rats were divided into four groups: control group, which received the vehicle for 6 days; MTX group, which received a single dose of MTX, followed by five daily doses of vehicle dosing; MTX + sitagliptin group, which received a single dose of MTX 1 h after the first sitagliptin treatment and six daily doses of sitagliptin; and sitagliptin group, which received sitagliptin for 6 days. Both MTX and sitagliptin were given as intraperitoneal injections at a dose of 20 mg/kg body weight. All rats were euthanized on the seventh day of the study. Kidney tissues were harvested and blood samples were collected. Serum levels of blood urea nitrogen (BUN) and creatinine were evaluated. Furthermore, catalase, glutathione peroxidase, superoxide dismutase activities, and malondialdehyde (MDA) levels were determined in kidney tissue. In addition, histopathological analysis was conducted. Histopathological evaluation showed that MTX-induced marked kidney injury. Biochemical analysis revealed a significant increase of BUN and creatinine in the serum of the MTX group. Furthermore, oxidative stress and depressed antioxidant system of the kidney tissues were evident in the MTX group. Sitagliptin did not affect these endpoints when administered alone, but it significantly attenuated the observed MTX-induced effects. These results suggest that sitagliptin exhibits potent anti-oxidant properties against the nephrotoxicity induced by MTX in rats.

Tetramethylpyrazine: An Active Ingredient of Chinese Herbal Medicine With Therapeutic Potential in Acute Kidney Injury and Renal Fibrosis

As an increasing public health concern worldwide, acute kidney injury (AKI) is characterized by rapid deterioration of kidney function. Although continuous renal replacement therapy (CRRT) could be used to treat severe AKI, effective drug treatment methods for AKI are largely lacking. Tetramethylpyrazine (TMP) is an active ingredient of Chinese herb Ligusticum wallichii (Chuan Xiong) with antioxidant and anti-inflammatory functions. In recent years, more and more clinical and experimental studies suggest that TMP might effectively prevent AKI. The present article reviews the potential mechanisms of TMP against AKI. Through search and review, a total of 23 studies were finally included. Our results indicate that the undergoing mechanisms of TMP preventing AKI are mainly related to reducing oxidative stress injury, inhibiting inflammation, preventing apoptosis of intrinsic renal cells, and regulating autophagy. Meanwhile, given that AKI and chronic kidney disease (CKD) are very tightly linked by each other, and AKI is also an important inducement of CKD, we thus summarized the potential of TMP impeding the progression of CKD through anti-renal fibrosis.

Effect of combination therapy with neural stem cell transplantation and teramethylpyrazine in rats following acute spinal cord injury

OBJECTIVES

This study was to explore the effects of teramethylpyrazine (TMP) administered in conjunction with neural stem cell transplantation on motor function, pathological lesions and the Janus kinase (JAK)2/signal transducer and activator of transcription 3 signal transduction pathway in rats following acute spinal cord injury (SCI).

METHODS

Female Sprague-Dawley rats were randomly divided into sham, model, neural stem cells (NSCs) and NSCs+TMP groups. Motor function was evaluated using the Basso, Beattie, Bresnahan scale. Spinal cord neuropathies and neuron apoptosis were observed by HE and TUNEL staining. The brain-derived neurotrophic factor (BDNF), Nogo-A, JAK2 and p-JAK2 protein levels were measured by western blot analysis.

RESULTS

NSCs+TMP significantly improved rat motor function, attenuated impaired spinal cords, and decreased cellular apoptosis, compared with NSCs therapy alone (P < 0.05). In addition, expression of BDNF protein was significantly higher in NSCs+TMP rats compared with other groups regardless of time postinjury (P < 0.05). The highest expression levels of Nogo-A protein were observed in the model group. The expression of p-JAK2 in the NSCs+TMP group was relatively lower than the model and NSCs groups (P < 0.05).

CONCLUSIONS

In rats with SCI, NSCs+TMP effectively improved motor function and offered spinal cord protection by increasing BDNF and decreasing Nogo-A levels, as well as inhibiting the JAK2/STAT3 signal transduction pathway, suggesting that TMP could be a useful agent in NSCs transplantation in the treatment of SCI.

Umbelliferone attenuates glycerol-induced myoglobinuric acute kidney injury through peroxisome proliferator-activated receptor-γ agonism in rats

Rhabdomyolysis is a clinical syndrome caused by damage to skeletal muscle, which consequently releases breakdown products into circulation and causes acute kidney injury (AKI) in humans. Intramuscular injection of glycerol mimics rhabdomyolysis and associated AKI. In this study, we explored the role of umbelliferone against glycerol-induced AKI in rats. Kidney function was assessed by measuring serum creatinine, urea, electrolytes, and microproteinuria. Renal oxidative stress was quantified using thiobarbituric acid reactive substances, superoxide anion generation, and reduced glutathione assay. Renal histological changes were determined using periodic acid Schiff and hematoxylin-eosin staining, and immunohistology of apoptotic markers (Bax, Bcl-2) was done. Serum creatine kinase was quantified to assess glycerol-induced muscle damage. Umbelliferone attenuated glycerol-induced change in biochemical parameters, oxidative stress, histological alterations, and renal apoptosis. Pretreatment with bisphenol A diglycidyl ether, a peroxisome proliferator-activated receptor-γ (PPAR-γ) antagonist, attenuated umbelliferone-mediated protection. It is concluded that umbelliferone attenuates glycerol-induced AKI possibly through PPAR-γ agonism in rats.

The Therapeutic Strategies for Uremic Toxins Control in Chronic Kidney Disease

Uremic toxins (UTs) are mainly produced by protein metabolized by the intestinal microbiota and converted in the liver or by mitochondria or other enzymes. The accumulation of UTs can damage the intestinal barrier integrity and cause vascular damage and progressive kidney damage. Together, these factors lead to metabolic imbalances, which in turn increase oxidative stress and inflammation and then produce uremia that affects many organs and causes diseases including renal fibrosis, vascular disease, and renal osteodystrophy. This article is based on the theory of the intestinal-renal axis, from bench to bedside, and it discusses nonextracorporeal therapies for UTs, which are classified into three categories: medication, diet and supplement therapy, and complementary and alternative medicine (CAM) and other therapies. The effects of medications such as AST-120 and meclofenamate are described. Diet and supplement therapies include plant-based diet, very low-protein diet, probiotics, prebiotics, synbiotics, and nutraceuticals. The research status of Chinese herbal medicine is discussed for CAM and other therapies. This review can provide some treatment recommendations for the reduction of UTs in patients with chronic kidney disease.

Intra-Articular Injection of a Nanosuspension of Tetramethylpyrazine Dihydroxynaphthalenate for Stronger and Longer-Lasting Effects Against Osteoarthritis

Tetramethylpyrazine (TMP), isolated from the rhizome of the traditional Chinese medicinal plant Chuanxiong (Ligusticum wallichii Franchat) shows therapeutic efficacy against osteoarthritis. After intra-articular injection, the retention time of TMP in the joint cavity is short, which limits its treatment effect. To avoid this problem, the present study explored the preparation of a TMP nanosuspension (TMP-NS) based on hydrophobic ion pairing. TMP-NS showed a particle size of approximately 588 nm and, after intra-articular injection in rats, it had longer retention in the articular cavity, higher TMP concentrations in joints, and greater anti-osteoarthritic efficacy than TMP solution. TMP-NS didn't cause significant inflammation at the joint. These results suggest that TMP-NS may strengthen and prolong the therapeutic efficacy of TMP against osteoarthritis without systemic toxicity.

Nephroprotective Effects of Tetramethylpyrazine Nitrone TBN in Diabetic Kidney Disease

Diabetic kidney disease (DKD) is the leading cause of end-stage renal failure, but therapeutic options for nephroprotection are limited. Oxidative stress plays a key role in the pathogenesis of DKD. Our previous studies demonstrated that tetramethylpyrazine nitrone (TBN), a novel nitrone derivative of tetramethylpyrazine with potent free radical-scavenging activity, exerted multifunctional neuroprotection in neurological diseases. However, the effect of TBN on DKD and its underlying mechanisms of action are not yet clear. Herein, we performed streptozotocin-induced rat models of DKD and found that TBN administrated orally twice daily for 6 weeks significantly lowered urinary albumin, N-acetyl-β-D-glycosaminidase, cystatin C, malonaldehyde, and 8-hydroxy-2′-deoxyguanosine levels. TBN also ameliorated renal histopathological changes. More importantly, in a nonhuman primate model of spontaneous stage III DKD, TBN increased the estimated glomerular filtration rate, decreased serum 3-nitrotyrosine, malonaldehyde and 8-hydroxy-2′-deoxyguanosine levels, and improved metabolic abnormalities. In HK-2 cells, TBN increased glycolytic and mitochondrial functions. The protective mechanism of TBN might involve the activation of AMPK/PGC-1α-mediated downstream signaling pathways, thereby improving mitochondrial function and reducing oxidative stress in the kidneys of DKD rodent models. These results support the clinical development of TBN for the treatment of DKD.

Renal-Protective Effects and Potential Mechanisms of Traditional Chinese Medicine after Ischemia-Reperfusion Injury

Renal ischemia-reperfusion (I/R) injury mainly causes acute kidney injury (AKI) after renal transplantation, trauma, sepsis, and hypovolemic shock. Patients with renal I/R injury are frequently associated with a poor prognosis. Traditional Chinese medicine (TCM) has been used for the prevention and treatment of various diseases in China and other Asian countries for centuries. Many studies have shown the protective effect of TCM on renal I/R injury, due to its diverse bioactive components. The potential mechanisms of TCMs on renal I/R injury include anti-inflammation, antioxidative effect, anti-cell death, downregulation of adhesion molecule expression, regulation of energy metabolism by restoring Na⁺-K⁺-ATPase activity, and mitochondrial fission. This review summarizes the major developments in the effects and underlying mechanisms of TCMs on the renal I/R injury.

Fenofibrate attenuates ischemia reperfusion-induced acute kidney injury and associated liver dysfunction in rats

Ischemia/reperfusion (I/R) is one of the common reasons for acute kidney injury (AKI) and we need to develop effective therapies for treating AKI. We investigated the role of fenofibrate against I/R-induced AKI and associated hepatic dysfunction in rats. In male wistar albino rats, renal pedicle occlusion for 40 min and 24 h reperfusion resulted in AKI. I/R-induced AKI was demonstrated by measuring serum creatinine, creatinine clearance, urea, uric acid, potassium, fractional excretion of sodium and urinary microproteins. Oxidative stress in rat kidneys was quantified by assaying superoxide anion generation, thiobarbituric acid reactive substances, and reduced glutathione levels. AKI-induced hepatic damage was quantified by assaying serum aminotransferases, alkaline phosphatase and bilirubin levels. Moreover, serum cholesterol, high density lipoprotein and triglycerides were quantified. Hematoxylin-eosin staining of renal and hepatic tissues was done and the kidney and liver injury scores were determined. Immunohistology of endothelial nitric oxide synthase (eNOS) was done in rat kidneys. Fenofibrate was administered for 1 week before subjecting rats to AKI. In separate group, the nitric oxide synthase inhibitor, L-nitroarginine methyl ester (L-NAME) was administered prior to fenofibrate treatment. In I/R group, significant alteration in the serum/urine parameters indicated AKI and hepatic dysfunction along with marked increase in kidney and liver injury scores. Treatment with fenofibrate attenuated AKI and associated hepatic dysfunction. Moreover, I/R-induced decrease in renal eNOS expression was abrogated by fenofibrate. Pre-treatment with L-NAME abolished fenofibrate mediated reno- and hepato-protective effects. In conclusion, fenofibrate attenuates I/R-induced AKI and associated hepatic dysfunction putatively through modulation of eNOS expression.

Protective effects of pharmacological agents against aminoglycoside-induced nephrotoxicity: A systematic review

Introduction: Aminoglycosides have been long used for antibacterial treatment and are still commonly used in clinical practice. Despite their extensive application and positive effects, drug-related toxicity is considered as the main obstacle for aminoglycosides. Aminoglycosides induce nephrotoxicity through the endocytosis and accumulation of the antibiotics in the epithelial cells of proximal tubule. Most importantly, however, a number of pharmacological agents were demonstrated to have protective activities against nephrotoxicity in experimental animals.Areas covered: In the present systematic review, the authors provide and discuss the mechanisms and epidemiological features of aminoglycoside-induced nephrotoxicity, and focus mainly on recent discoveries and key features of pharmacological interventions. In total, 39 articles were included in this review.Expert opinion: The majority of studies investigated gentamicin-induced nephrotoxicity in animal models. Antioxidants, chemicals, synthetic drugs, hormones, vitamins, and minerals showed potential values to prevent gentamicin-induced nephrotoxicity. Indicators used to evaluate the effectiveness of nephroprotection included antioxidative indexes, inflammatory responses, and apoptotic markers. Among the nephroprotective agents studied, herbs and natural antioxidant agents showed excellent potential to provide a protective strategy against gentamicin-induced nephrotoxicity.

Ligustrazine suppresses renal NMDAR1 and caspase-3 expressions in a mouse model of sepsis-associated acute kidney injury

Sepsis-associated acute kidney injury (AKI) is a life threatening condition with high morbidity and mortality. The pathogenesis of AKI is associated with apoptosis. In this study, we investigated the effects of ligustrazine (LGZ) on experimental sepsis-associated AKI in mice. Sepsis-associated AKI was induced in a mice model using cecal ligation and puncture (CLP) method. Mice were administered LGZ (10, 30, and 60 mg/kg) via tail vein injection 0.5 h before CLP surgery. Mice survival was evaluated. Renal water content was detected. Urine samples were collected for ELISA of Kim1. Kidneys were collected for nucleic acid analysis and histological examination. Pathological assessment was used to determine the effect of LGZ on sepsis-associated AKI. Caspase-3 expression in kidney was assessed by immunohistochemistry. Renal NMDAR1 level was also determined. Treatment of LGZ improved mice survival rate; the effect was significant when administered at a high LGZ dose (60 mg/kg). Renal water content of mice undergoing CLP was significantly reduced by LGZ treatment. Both middle-dose and high-dose LGZ treatments reduced urine Kim1 level in sepsis-associated AKI mice. The severity of AKI in septic mice was reduced by middle-dose and high-dose LGZ administration. Immunohistochemical analysis revealed decreased caspase-3 and NMDAR1 levels in the kidney following middle-dose and high-dose LGZ treatments. RT-PCR assay showed a significant reduction in NMDAR1 mRNA expression in the kidney of middle-dose and high-dose LGZ-treated mice. LGZ exhibited protective effects against sepsis-associated AKI in mice, possibly via downregulation of renal NMDAR1 expression and its anti-apoptotic action by inhibiting caspase-3.

The protective effect of ligustrazine on rats with cerebral ischemia-reperfusion injury via activating PI3K/Akt pathway

The study was to investigate the effects of ligustrazine on rats with cerebral ischemia-reperfusion (I/R) injury and to explore the potential mechanism. Transient focal cerebral ischemia Wistar rat model was established through middle cerebral artery occlusion. The cerebral I/R injury rats were treated with intraperitoneal injection of ligustrazine (1, 3, and 10 mg/kg). Human amniotic epithelial cells (HAECs) were treated with ligustrazine (1, 10, 100 μM) and PI3K inhibitor wortmannin (100 μM), following oxygen-glucose deprivation (OGD) treatment. The expression levels of protein kinase B (PKB or AKT), phospho-Akt (p-Akt), endothelial nitric oxide synthase (eNOS), and phosphor-eNOS (p-eNOS) in HAECs and brains of rats were measured by Western blot. The levels of nitric oxide (NO) in HAECs were measured by Griess method using NO^2-/NO^3- Assay Kit. Infarct volume and neurological deficits were evaluated 24 h after reperfusion. The levels of NO, p-Akt/Akt, and p-eNOS/eNOS in HAECs were significantly reduced after OGD, but ligustrazine treatment increased the levels of those factors in a dose-dependent manner, while those increases were reversed by PI3K inhibitor wortmannin. Similarly, p-Akt/Akt and p-eNOS/eNOS in brain tissue of rats with I/R were significantly reduced compared with control group (p < 0.05), but ligustrazine treatment increased the levels of p-Akt and p-eNOS in a dose-dependent manner (p < 0.05), while those increases were also reversed by using wortmannin. Ligustrazine also improved the damage of rat brain tissue caused by I/R, but wortmannin reversed the improvement. Ligustrazine plays a neuroprotective role in rats with cerebral I/R injury through the activation of PI3K/Akt pathway.

Intra-articular delivery of tetramethylpyrazine microspheres with enhanced articular cavity retention for treating osteoarthritis

Tetramethylpyrazine (TMP) is a traditional Chinese herbal medicine with strong anti-inflammatory and cartilage protection activities, and thus a promising candidate for treating osteoarthritis. However, TMP is rapidly cleared from the joint cavity after intra-articular injection and requires multiple injections to maintain efficacy. The aim of this study was to encapsulate TMP into poly (lactic-co-glycolic acid) (PLGA) microspheres to enhance the TMP retention in the joint, reducing injection frequencies and decreasing dosage. TMP microspheres were prepared by emulsion/solvent evaporation method. The intra-articular retention of the drug was assessed by detecting the drug concentration distributed in the joint tissue at different time points. The therapeutic effect of TMP microspheres was evaluated by the swelling of knee joints and histologic analysis in papain-induced OA rat model. The prepared freeze-dried microspheres with a particle size of about 10 µm can effectively prolong the retention time of the drug in the articular cavity to 30 d, which is 4.7 times that of the TMP solution. Intra-articular injection of TMP microspheres efficiently relieved inflammatory symptoms, improved joint lesions and decreased the depletion of proteoglycan. In conclusion, intra-articular injection of TMP loaded microspheres was a promising therapeutic method in the treatment of OA.

The role of hypertriglyceridemia for acute kidney injury in the course of acute pancreatitis and an animal model

OBJECTIVE

The aim of this study was to investigate the role of hypertriglyceridemia for acute kidney injury (AKI) in the course of acute pancreatitis.

METHODS

Patients with acute pancreatitis were retrospectively divided into four groups according to admission triglyceride: normal group, mild HTG group, moderate HTG group and severe HTG group. Clinical characteristics were compared among these groups. Wild type (WT) mice and Human ApoC III transgenic (ApoCIIItg) mice were used in the next animal experiments. Severe acute pancreatitis (SAP) model was established by retrograde injection of 0.5% sodium taurocholate (0.1 ml/100 g) from duodenum to pancreatic duct. Histological scores, serum amylase, creatinine, usea nitrogen were compared between WT mice and ApoCIIItg mice.

RESULTS

Two hundred and sixty-two patients were classified into 4 groups: normal TG (104, 39.7%), mild HTG (72, 27.5%), moderate HTG (47, 17.9%), and severe HTG (39, 14.9%) groups. The proportions of AKI were 13.5% (14/104, normal), 13.9% (10/72, mild), 21.3% (10/47, moderate), and 38.5% (15/39, severe), respectively. After establishing SAP model, the levels of serum amylase (P < 0.05) and pancreatic histological score (P < 0.05) of ApoCIII-SAP-9h group were significantly higher than that of WT-SAP-9h group, respectively. ApoCIII-SAP-9h group had significantly higher levels of serum creatinine (P < 0.001), usea nitrogen (P < 0.001), and kidney histological score (P < 0.05) than that of WT-SAP-9h group, respectively.

CONCLUSIONS

Mild HTG has little adverse impact on disease severity of acute pancreatitis; severe HTG can aggravate kidney injury in the course of acute pancreatitis. ApoCIII-SAP mice have more serious pancreatic damage and kidney injury than WT-SAP mice.

Effect of Tetramethylpyrazine on Atherosclerosis and SCAP/SREBP-1c Signaling Pathway in ApoE-/- Mice Fed with a High-Fat Diet

Lipid metabolism dysregulation plays a crucial role in the occurrence of atherosclerosis (As). SCAP/SREBP signaling is the main pathway for regulating lipid metabolism. Tetramethylpyrazine (TMP), a Traditional Chinese Medicine (TCM) for treating angina pectoris, has antiatherosclerotic effects and ameliorates blood lipids disturbance. However, its precise mechanism remains unclear. This study investigated the mechanism of TMP in ameliorating As in mice model. After six weeks of high-fat diet, 30 ApoE^−/− mice were randomized (n = 10) and treated with Lipitor, TMP, or distilled water for six weeks. The serum blood lipids and insulin levels were measured. The expressions of PAQR3, Insig-1, SCAP, SREBP-1c, IRS-1, PI3K, Akt, and mTORC-1 in the adipose tissues were determined. The results showed that TMP could significantly decrease blood lipids levels, insulin, and corrected plaque area of the ApoE^−/− mice as compared to the untreated mice (P < 0.05, P < 0.01). Moreover, TMP could significantly downregulate the expressions of SCAP, SREBP-1c, PAQR3, IRS-1, PI3K, Akt, and mTORC1 (P < 0.01). Thus, TMP may ameliorate lipid metabolism disorder and As by downregulating PAQR3 and inhibiting SCAP/SREBP-1c signaling pathway. In addition, PI3K/Akt/mTORC1 signaling pathway may be involved in this process.

Effects and mechanisms of compound Chinese medicine and major ingredients on microcirculatory dysfunction and organ injury induced by ischemia/reperfusion

Microcirculation dysfunction and organ injury after ischemia and reperfusion (I/R) result from a complex pathologic process consisting of multiple links, with metabolism impairment in the ischemia phase and oxidative stress in the reperfusion phase as initiators, and any treatment targeting a single link is insufficient to cope with this. Compound Chinese medicine (CCM) has been applied in clinics in China and some Asian nations for >2000years. Studies over the past decades revealed the protective and therapeutic effect of CCMs and major ingredients on I/R-induced microcirculatory dysfunction and tissue injury in the heart, brain, liver, intestine, and so on. CCM contains diverse bioactive components with potential for energy metabolism regulation; antioxidant effect; inhibiting inflammatory cytokines release; adhesion molecule expression in leukocyte, platelet, and vascular endothelial cells; and the protection of thrombosis, albumin leakage, and mast cell degranulation. This review covers the major works with respect to the effects and underlying mechanisms of CCM and its ingredients on microcirculatory dysfunction and organ injury after I/R, providing novel ideas for dealing with this threat.

Siwu decoction attenuates oxonate-induced hyperuricemia and kidney inflammation in mice

The aim of the study was to investigate the effects of Siwu decoction on hyperuricemia, kidney inflammation, and dysfunction in hyperuricemic mice. Siwu decoction at 363.8, 727.5, and 1 455 mg·kg(-1) was orally administered to potassium oxonate-induced hyperuricemic mice for 7 days. Serum urate, creatinine, and blood urea nitrogen levels and hepatic xanthine oxidase (XOD) activity were measured. The protein levels of hepatic XOD and renal urate transporter 1 (URAT1), glucose transporter 9 (GLUT9), organic anion transporters 1 (OAT1), ATP-binding cassette subfamily G member 2 (ABCG2), organic cation transporter 1 (OCT1), OCT2, organic cation/carnitine transporter 1 (OCTN1), OCNT2, Nod-like receptor family, pyrin domain containing 3 (NLRP3), apoptosis-associated speck-like protein (ASC), Caspase-1, and interleukin-1β (IL-1β) were determined by Western blotting. Renal histopathology change was obtained following hematoxylin-eosin staining. Our results indicated that Siwu decoction significantly reduced serum urate, creatinine and blood urea nitrogen levels and increased fractional excretion of uric acid in hyperuricemic mice. It effectively reduced hepatic XOD activity and protein levels in this animal model. Furthermore, Siwu decoction down-regulated URAT1 and GLUT9 protein levels, and up-regulated the protein levels of OAT1, ABCG2, OCT1, OCT2, OCTN1, and OCTN2 in the kidney of the hyperuricemic mice. Additionally, Siwu decoction remarkably reduced renal protein levels of NLRP3, ASC, Caspase-1, and IL-1β in the hyperuricemic mice. These results suggested that Siwu decoction exhibited anti-hyperuricemic and anti-inflammatory effects by inhibiting hepatic XOD activity, regulating renal organic ion transporter expression, and suppressing renal NLRP3 inflammasome activation, providing the evidence for its use in the treatment of hyperuricemia and associated kidney inflammation.

Efficacy of Chinese Herbal Medicine as an Adjunctive Therapy on in-Hospital Mortality in Patients with Acute Kidney Injury: A Systematic Review and Meta-Analysis

Objective. We aimed to systematically assess the efficacy of Chinese herbal medicine (CHM) as an adjunctive therapy on in-hospital mortality in patients with acute kidney injury (AKI). Methods. We did a systematic review of articles published in any language up until Jun 23, 2015, by searching PubMed, Embase, the Cochrane Library, CBM, and CNKI. We included all RCTs that compared outcomes of patients with AKI taking CHM plus Western treatment (WT) with those taking WT alone. We applied Cochrane risk-of-bias tool to assess the methodological quality of the included trials. Results. Of 832 citations, 15 studies involving 966 patients met inclusion criteria. The methodological quality was assessed with unclear risk of bias. In the primary outcome of meta-analysis, pooled outcome of in-hospital mortality showed that patients randomly assigned to CHM treatment group were associated with low risk of in-hospital mortality compared with those randomly assigned to WT alone (RR = 0.41; 95% CI = 0.24 to 0.71; P = 0.001). Conclusions. CHM as an adjunctive therapy is associated with a decreased risk of in-hospital mortality compared with WT in patients with AKI. Further studies with high quality and large sample size are needed to verify our conclusions.

Efficacy of Ligustrazine Injection as Adjunctive Therapy for Angina Pectoris: A Systematic Review and Meta-Analysis

Background

In the past decades, a large number of randomized controlled trials (RCTs) on the efficacy of ligustrazine injection combined with conventional antianginal drugs for angina pectoris have been reported. However, these RCTs have not been evaluated in accordance with PRISMA systematic review standards. The aim of this study was to evaluate the efficacy of ligustrazine injection as adjunctive therapy for angina pectoris.

Material/Methods

The databases PubMed, Medline, Cochrane Library, Embase, Sino-Med, Wanfang Databases, Chinese Scientific Journal Database, Google Scholar, Chinese Biomedical Literature Database, China National Knowledge Infrastructure, and the Chinese Science Citation Database were searched for published RCTs. Meta-analysis was performed on the primary outcome measures, including the improvements of electrocardiography (ECG) and the reductions in angina symptoms. Sensitivity and subgroup analysis based on the M score (the refined Jadad scores) were also used to evaluate the effect of quality, sample size, and publication year of the included RCTs on the overall effect of ligustrazine injection.

Results

Eleven RCTs involving 870 patients with angina pectoris were selected in this study. Compared with conventional antianginal drugs alone, ligustrazine injection combined with antianginal drugs significantly increased the efficacy in symptom improvement (odds ratio [OR], 3.59; 95% confidence interval [CI]: 2.39 to 5.40) and in ECG improvement (OR, 3.42; 95% CI: 2.33 to 5.01). Sensitivity and subgroup analysis also confirmed that ligustrazine injection had better effect in the treatment of angina pectoris as adjunctive therapy.

Conclusions

The 11 eligible RCTs indicated that ligustrazine injection as adjunctive therapy was more effective than antianginal drugs alone. However, due to the low quality of included RCTs, more rigorously designed RCTs were still needed to verify the effects of ligustrazine injection as adjunctive therapy for angina pectoris.

A UPLC-MS/MS method for simultaneous determination of danshensu, protocatechuic aldehyde, rosmarinic acid, and ligustrazine in rat plasma, and its application to pharmacokinetic studies of Shenxiong glucose injection in rats

A rapid and sensitive ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed for the simultaneous determination of the four major active ingredients, danshensu, protocatechuic aldehyde, rosmarinic acid, and ligustrazine, in the traditional Chinese medicine Shenxiong glucose injection in rat plasma. Acidified and alkalized plasma samples were extracted using ethyl acetate, and separated on a Waters C18 column (2.1mm×50mm, 1.7μm) by using a gradient mobile phase system of acetonitrile-water containing 0.1% formic acid and luteoloside as an internal standard. Electrospray ionization in the positive-ion mode and multiple reaction monitoring were used to identify and quantitate the active components. All calibration curves showed good linearity (r>0.994) over the concentration range, with a lower limit of quantification (LLOQ) between 0.02 and 0.21μg/mL. The precision of the in vivo study was evaluated by intra- and inter-day assays, and the percentage of relative standard deviation was within 15%. Moreover, satisfactory extraction efficiency was obtained (between 83.94 and 117.81%) by liquid-liquid extraction. The validated method was successfully applied in a pharmacokinetic study in rats after intravenous administration of Shenxiong glucose injection. The results showed that the four bioactive ingredients in Shenxiong glucose injection have linear pharmacokinetic properties in rats after intravenous injection within the administered dose range and partially different ones compared to single ingredient.

Effects of notoginsenoside R1 on CYP1A2, CYP2C11, CYP2D1, and CYP3A1/2 activities in rats by cocktail probe drugs

CONTEXT

Notoginsenoside R1 (NGR1) is the main component with cardiovascular activity in Panax notoginseng (Burk.) F. H. Chen, an herbal medicine that is widely used to enhance blood circulation and dissipate blood stasis.

OBJECTIVE

The objective of this study is to investigate NGR1's effects on CYP1A2, CYP2C11, CYP2D1, and CYP3A1/2 activities in rats in vivo through the use of the Cytochrome P450 (CYP450) probe drugs.

MATERIALS AND METHODS

After pretreatment with NGR1 or physiological saline, the rats were administered intraperitoneally with a mixture solution of cocktail probe drugs containing caffeine (10 mg/kg), tolbutamide (15 mg/kg), metoprolol (20 mg/kg), and dapsone (10 mg/kg). The bloods were then collected at a set of time-points for the ultra-performance liquid chromatography/tandem mass spectrometry (UPLC-MS/MS) analysis.

RESULTS

NGR1 was shown to exhibit an inhibitory effect on CYP1A2 by increased caffeine Cmax (43.13%, p < 0.01) and AUC0 - ∞ (40.57%, p < 0.01), and decreased CL/F (62.16%, p < 0.01) in the NGR1-treated group compared with those of the control group, but no significant changes in pharmacokinetic parameters of tolbutamide, metoprolol, and dapsone were observed between the two groups, indicating that NGR1 had no effects on rat CYP2C11, CYP2D1, and CYP3A1/2.

DISCUSSION AND CONCLUSION

When NGR1 is co-administered with drugs that are metabolized by CYP1A2, the pertinent potential herb-drug interactions should be monitored.

Detection of renal brush border membrane enzymes for evaluation of renal injury in neonatal scleredema

OBJECTIVE

To evaluate renal brush border membrane enzymes in urine as an indicator for renal injury in neonatal scleredema (NS).

METHODS

Sixty nine NS patients in our hospital were enrolled and divided into mild group and moderate/severe group. Patients were further randomly divided into therapy and control subgroups for 7 days ligustrazine administration. Urine samples were collected to detect renal brush border membrane enzymes (RBBME) by ELISA and β2-microglobulin (β2-MG) by radioimmunoassay (RIA). The results were compared with those of 30 normal neonates. Data were statistically analyzed using SPSS13.0 software.

RESULTS

Both RBBME and β2-MG were found to be higher in urine in NS patients than normal controls (P < 0.01). Level of RBBME increased with the severity of NS (P <0.05), while urinary β2-MG did not (P >0.05). After being treated with ligustrazine, a medicine for renal function recovery, both RBBME and β2-MG were similarly significantly decreased comparing to untreated groups (P < 0.05). 79.7% of NS patients showed abnormal RBBME while only 52.2% had an abnormal urinary β2-MG (χ (2)=11.65，P < 0.01).

CONCLUSION

RBBME was more sensitive than β2-MG in reflecting the renal injury in NS. Examination of RBBME effectively reflected the recovery of renal injury after treatment with ligustrazine.

Suxiao jiuxin pill induces potent relaxation and inhibition on contraction in human artery and the mechanism

Suxiao Jiuxin Pill, a compound Chinese traditional medicine with main components of tetramethylpyrazine and borneol, is widely used for antiangina treatment in China but its pharmacological effect on human blood vessels is unknown. We investigated the effect and possible mechanism of SJP in the human internal mammary artery (IMA, n = 78) taken from patients undergoing coronary surgery. SJP caused full relaxation in KCl- (99.4 ± 10.5%, n = 6) and U46619- (99.9 ± 5.6%, n = 6) contracted IMA. Pretreatment of IMA with plasma concentrations of SJP (1 mg/mL), calculated from the plasma concentration of its major component borneol, significantly depressed the maximal contraction to KCl (from 35.8 ± 6.0 mN to 12.6 ± 5.6 mN, P = 0.03) and U46619 (from 19.4 ± 2.9 mN to 5.7 ± 2.4 mN, P = 0.007) while SJP at 10 mg/mL abolished the subsequent contraction. Endothelium denudation and inhibition of eNOS significantly altered the SJP-induced relaxation without changes of eNOS expression. We conclude that SJP has a potent inhibitory effect on the vasoconstriction mediated by a variety of vasoconstrictors in human arteries. The vasorelaxation involves both endothelium-dependent and -independent mechanisms. Thus, the effect of SJP on human arteries demonstrated in this study may prove to be particularly important in vasorelaxing therapy in cardiovascular disease.

Effects of Ligustrazine on DNA damage and apoptosis induced by irradiation

Ligustrazine has been used to treat heart and blood vessel disease in China. In the present study, we investigated the potential action of Ligustrazine as a component of chuanxiong (a Chinese herb) in scavenging hydroxyl radical and superoxide radical as indicated in the ESR spin-trapping measurement. Treatment of Ligustrazine in mice decreased mortality after whole body γ-irradiation. The anti-radiation action of Ligustrazine was studied by measuring DNA damage (Comet assay and γ-H2AX formation) and apoptosis induced by irradiation. It was triggered by altering the level of DNA-PKcs protein, a critical component of DNA double-strand break (DSB) repair pathways in mice after irradiation. Consistently, the phosphorylation of Akt protein, a mediator of survival signaling, was concurrently increased by Ligustrazine treatment. Additionally, the cytokines along with the phosphorylation of the p38 protein which is activated by a variety of environmental stresses and inflammatory cytokines decreased in the Ligustrazine-treated group as compared to irradiation group. Our results suggest that Ligustrazine has radioprotective effect through its capabilities as a powerful antioxidant, in reducing reactive oxygen species (ROS) level induced by irradiation, minimizing DNA damage and apoptosis, and activating survival signal Akt pathways. This study will be of value in the development of novel radioprotective compounds.

Comparison of the effects of dexmedetomidine administered at two different times on renal ischemia/reperfusion injury in rats

BACKGROUND AND OBJECTIVES

We investigated the effect of dexmedetomidine on ischemic renal failure in rats.

METHODS

In the present study, 26 male adult Wistar albino rats weighting 230-300 g were randomly separated into four groups: sham-operated (n=5), ischemia reperfusion (IR) (IR group, n=7), IR/reperfusion treatment with dexmedetomidine (Dex. R group, n=7) and IR/pre-ischemic treatment with dexmedetomidine (Dex. I group, n=7). In the first group, sham operation was achieved and renal clamps were not applied. For the IR group, renal ischemia was induced by occlusion of the bilateral renal arteries and veins for 60 min followed by reperfusion for 24h. For the Dex. R and Dex. I groups, the same surgical procedure as in the IR group was performed, and dexmedetomidine (100 mcg/kg intraperitoneal) was administrated at the 5th min after reperfusion and before ischemia. At the end of reperfusion, blood samples were drawn, the rats were sacrificed, and the left kidney was processed for histopathology.

RESULTS

The blood urea nitrogen (BUN) levels in groups Dex. R and Dex. I were significantly lower than in the IR group (p=0.015, p=0.043), although urine flow was significantly higher in group Dex. R (p=0.003). The renal histopathological score in the IR group was significantly higher than in the other groups. There was no significant difference between the Dex. R and Dex. I groups.

CONCLUSIONS

The results were shown that administration of dexmedetomidine reduced the renal IR injury histomorphologically. Administration of dexmedetomidine in the reperfusion period was considered as more effective due to increase in urinary output and decrease in BUN levels.

Advances in the chemical analysis and biological activities of chuanxiong

Chuanxiong Rhizoma (Chuan-Xiong, CX), the dried rhizome of Ligusticum chuanxiong Hort. (Umbelliferae), is one of the most popular plant medicines in the World. Modern research indicates that organic acids, phthalides, alkaloids, polysaccharides, ceramides and cerebrosides are main components responsible for the bioactivities and properties of CX. Because of its complex constituents, multidisciplinary techniques are needed to validate the analytical methods that support CX's use worldwide. In the past two decades, rapid development of technology has advanced many aspects of CX research. The aim of this review is to illustrate the recent advances in the chemical analysis and biological activities of CX, and to highlight new applications and challenges. Emphasis is placed on recent trends and emerging techniques.

Protective effect of ligustrazine against myocardial ischaemia reperfusion in rats: the role of endothelial nitric oxide synthase

1. The aim of the present study was to determine whether ligustrazine (2,3,5,6-tetramethylpyrazine; TMP) exerts a cardioprotective effect during myocardial ischaemia reperfusion (IR), and to investigate the underlying mechanisms and the role of endothelial nitric oxide synthase (eNOS) in cardioprotection. 2. Sprague-Dawley rats were divided into a sham group and five IR groups: IR control, TMP pretreated, TMP + wortmannin (a phosphatidylinositol 3-kinase (PI3K) inhibitor), N(G) -nitro-L-arginine methyl ester (L-NAME; a NOS inhibitor) and TMP + L-NAME. IR was produced by 35 min of regional ischaemia followed by 120 min of reperfusion. Myocardial infarct size, oxidative stress, myocardial apoptosis, nitric oxide (NO) production, and expression of phosphorylated protein kinase B (Akt) and eNOS were measured. 3. TMP markedly decreased infarct size and attenuated myocardial apoptosis, as evidenced by a decrease in the apoptotic index and reduced caspase-3 activity. TMP treatment caused a marked increase in NO production. Cotreatment with wortmannin or L-NAME completely blocked the TMP-induced NO increase. TMP induced phosphorylation of Akt at Ser 473 (1.61 ± 0.18 vs 0.79 ± 0.10 in the IR control group) and phosphorylation of eNOS at Ser1177 (1.87 ± 0.33 vs 0.94 ± 0.22 in the IR control group). Wortmannin abrogated the phosphorylation of Akt and eNOS induced by TMP. 4. These data suggest that ligustrazine has anti-apoptotic and cardioprotective effects against myocardial IR injury and that it acts through the PI3K/Akt pathway. In addition, the phosphorylation of eNOS with subsequent NO production was found to be an important downstream effector that contributes significantly to the cardioprotective effect of TMP.

Meta-Analysis of the Clinical Effect of Ligustrazine on Diabetic Nephropathy

Ligustrazine, a bioactive component contained in Chuanxiong (Ligusticum chuanxiong Hort), is widely applied in the treatment of vascular diseases in China, e.g. myocardial and cerebral infarction. The aim of this study was to perform a meta-analysis of randomized controlled trials (RCTs) to evaluate the clinical effect of Ligustrazine on diabetic nephropathy (DN). PUBMED, EMBASE, the Cochrane Central Register of Controlled Trials (CENTRAL), Chinese Biological Medicine Database (CBM), China National Knowledge Infrastructure (CNKI) Database, etc. were searched by computer and manual methods to identify RCTs that were used to evaluate the clinical effect of Ligustrazine on DN patients. Twenty five studies comprising 25 RCTs were involved including 1645 patients (858 in the treatment group and 787 in the control group). The meta-analysis suggests that compared with the control group, Ligustrazine injection has a significant therapeutic effect on improving renal function (blood urea nitrogen [BUN] and serum creatinine [SCr]) and reducing in urine protein (24 h urine protein, urine micro albumin and urinary albumin excretion rate [UAER]) in DN patients.

Protective effects of Radix Codonopsis on ischemia-reperfusion injury in rats after kidney transplantation

PURPOSE

Kidney ischemia-reperfusion injury (IRI) after kidney transplant remains a major problem, separate from immune rejection that can lead to kidney transplant failure and graft function loss. Free radicals, disturbance of microcirculation and the inflammatory cascade appear to be the main contributors. Radix Codonopsis, a traditional Chinese drug used in vascular diseases, is an antioxidant and free radical scavenger. This study investigates the protective effect and underlying mechanisms of Radix Codonopsis extract saponins on kidney transplantation.

METHODS

Renal transplantation was performed after rat kidneys had been stored for 1 h at 4°C. Blood urea nitrogen (BUN), serum creatinine (Scr), superoxide dismutase (SOD) and malondialdehyde (MDA) were assayed; bcl-2 and bax mRNA expression was detected using RT-PCR; bcl-2 and bax protein expression was detected by immunohistochemistry (IHC). Terminal deoxynucleotidyl transferase biotin-dUTP nick end labeling (TUNEL) was used to detect apoptotic cells and determine the apoptosis index (AI). Analysis of variance (ANOVA) followed by Dunnett's test was used when more than two groups were compared.

RESULTS

Saponin-treated animals showed increased SOD levels accompanied by decreased MDA, Scr and BUN levels (p < 0.05 vs. untreated controls); bcl-2 mRNA and protein levels were increased in transplanted kidney from treated animals, while bax mRNA and protein levels were decreased (p < 0.05 vs. untreated controls). AI was significantly decreased in transplanted kidneys from treated animals relative to untreated controls (p < 0.05 vs. untreated controls).

CONCLUSION

This study clearly demonstrates the protective effects on IRI after kidney transplantation, which may be explained by decreased lipid peroxidation and inhibition of apoptosis.

Effects of ligustrazine on ureteral obstruction-induced renal tubulointerstitial fibrosis

Ligustrazine (LIG) is a purified and chemically identified component of the Chinese herb Ligusticum wallichii Franchat. It is a potent blocker of vasoconstriction and has strong scavenger of oxygen free radicals. We investigated the effect of LIG on renal tubulointerstitial fibrosis using a rat model of unilateral ureteral obstruction. Ligustrazine treatment significantly reduced the scores of interstitial collagen deposition, amounts of hydroxyproline, the density of myofibroblasts and macrophages, and amounts of transforming growth factor-β1 (TGF-β1) and connective tissue growth factor (CTGF) compared with their level in a saline-treated control group. Using quantitative polymerase chain reaction we found that LIG treatment significantly reduced the mRNA expression of TGF-β1, CTGF, monocyte chemoattractant protein-1 and osteopontin. Moreover, the mRNA expression of hepatocyte growth factor and bone morphogenetic protein-7 were significantly increased by LIG. In vitro, LIG inhibited the TGF-β1-induced loss of cytokeratin-18 expression and de novo increase of the expression of α-smooth muscle actin of HK-2 cells in a dose-dependent manner, which suggested that LIG could restrain the process of epithelial-myofibroblast transition of tubular epithelial cells. This study indicates that LIG can attenuate renal tubulointerstitial fibrosis. It might be useful as a potential candidate in the treatment of chronic renal diseases.

Synthetic and natural iron chelators: therapeutic potential and clinical use

Iron-chelation therapy has its origins in the treatment of iron-overload syndromes. For many years, the standard for this purpose has been deferoxamine. Recently, considerable progress has been made in identifying synthetic chelators with improved pharmacologic properties relative to deferoxamine. Most notable are deferasirox (Exjade(®)) and deferiprone (Ferriprox(®)), which are now available clinically. In addition to treatment of iron overload, there is an emerging role for iron chelators in the treatment of diseases characterized by oxidative stress, including cardiovascular disease, atherosclerosis, neurodegenerative diseases and cancer. While iron is not regarded as the underlying cause of these diseases, it does play an important role in disease progression, either through promotion of cellular growth and proliferation or through participation in redox reactions that catalyze the formation of reactive oxygen species and increase oxidative stress. Thus, iron chelators may be of therapeutic benefit in many of these conditions. Phytochemicals, many of which bind iron, may also owe some of their beneficial properties to iron chelation. This review will focus on the advances in iron-chelation therapy for the treatment of iron-overload disease and cancer, as well as neurodegenerative and chronic inflammatory diseases. Established and novel iron chelators will be discussed, as well as the emerging role of dietary plant polyphenols that effectively modulate iron biochemistry.

Ligustrazine inhibits lipopolysaccharide-induced proliferation by affecting P27, Bcl-2 expression in rat mesangial cells

Ligustrazine has a renoprotective effect against nephritis. In the present study, we investigated the roles of ligustrazine on lipopolysaccharide-induced changes of proliferation, cell cycle in cultured rat mesangial cells. 3-(4,5-dimethyltiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay revealed that rat mesangial cells treated with lipopolysaccharide (10mg/l) underwent significant proliferation compared with control group. This effect was significantly inhibited by ligustrazine (400 to 2500 mg/l). Flow cytometric analysis revealed that cells treated with lipopolysaccharide showed significant reduction in the ratio of G0/G1 phase and significant elevation in the ratio of S+G2/M phase. The changes of cell cycle induced by lipopolysaccharide were reversed by ligustrazine. In addition, lipopolysaccharide suppressed P27 protein expression was significantly increased by ligustrazine (100, 500, 2500 mg/l). Moreover, rat mesangial cells treated with lipopolysaccharide showed scanty apoptosis with up-regulation of Bcl-2expression, while Bax protein expression was not changed. Ligustrazine (100, 500, 2500 mg/l) significantly reversed lipopolysaccharide-induced up-regulation of Bcl-2 protein and increased apoptotic cell death. In summary, ligustrazine displayed a significant inhibiting effect on lipopolysaccharide-induced proliferation through increasing P27 and decreasing Bcl-2 protein expression in rat mesangial cells.

Tetramethylpyrazine inhibits hypoxia-induced pulmonary vascular leakage in rats via the ROS-HIF-VEGF pathway

Tetramethylpyrazine (TMP) is a reactive oxygen species (ROS) antagonist that has potent properties for the treatment of a variety of vascular diseases, such as ischemic stroke and pulmonary hypertension secondary to chronic obstructive pulmonary diseases. However, there are few data about the role of TMP in hypoxia-induced pulmonary vascular leakage. This study examined the effect of TMP on hypoxia-induced pulmonary vascular leakage and the underlying mechanisms. Rat pulmonary microvascular endothelial cells (RPMVECs) treated with TMP or not were subjected to hypoxic or normoxic conditions for 24 h, and the monolayer permeability, intracellular ROS, hypoxia-inducible factor-1α (HIF-1α) and vascular endothelial growth factor (VEGF) proteins levels were determined. Additionally, rats administrated TMP were exposed to hypobaric hypoxia to evaluate the effect of TMP in vivo by measuring lung water content, pulmonary vascular leakage into the lungs and immunohistochemistry for HIF-1α and VEGF. Hypoxia was found to cause a significant increase in RPMVEC monolayer permeability and intracellular ROS, HIF-1α and VEGF protein levels. Treatment with TMP decreased the hypoxia-induced RPMVEC monolayer permeability and attenuated the elevation of ROS, HIF-1α and VEGF protein levels. TMP-treated animals showed less pulmonary vascular leakage and HIF-1α and VEGF expression compared with those exposed to hypoxia alone. These observations supported that TMP inhibited the increase in pulmonary vascular permeability induced by hypoxia. The underlying mechanisms may be related to the scavenging of intracellular ROS and the suppression of hypoxia-induced upregulation of HIF-1α and VEGF proteins.

Notoginsenoside R1 attenuates renal ischemia-reperfusion injury in rats

Ischemia-reperfusion (I/R) injury of the kidney is a complex pathophysiological process and a major cause of acute renal failure. It has been shown that I/R injury is related to inflammatory responses and activation of apoptotic pathways. Inhibition of certain elements of inflammatory responses and apoptotic pathway seemed to ameliorate renal I/R injury. As an effective element of Panax notoginseng, NR1 has antioxidant, anti-inflammatory, antiapoptotic, and immune-stimulatory activities. Therefore, we speculate that NR1 can attenuate renal I/R injury. Ischemia-reperfusion injury was induced by renal pedicle ligation followed by reperfusion along with a contralateral nephrectomy. Male Sprague-Dawley rats were randomized to four groups: sham group, I/R control group, NR1-1 group (rats treated with NR1, 20 mg.kg.d) and NR1-2 group (rats treated with NR1, 40 mg.kg.d). All animals were killed 72 h after I/R induction. Blood and renal tissues were collected. Renal dysfunction was observed by the level of serum creatinine and histological evaluation. Apoptosis and inflammatory response in the tissue of kidney were detected mainly with molecular biological methods. NR1 attenuated I/R-induced renal dysfunction as indicated by the level of serum creatinine and histological evaluation. It prevented the I/R-induced increases in the levels of proinflammatory cytokine TNF-alpha, myeloperoxidase activity, phosphorylation of p38, and activation of nuclear factor kappaB with cell apoptosis in the kidney and enhanced expression of antiapoptosis cytokine bcl-2. Treatment with NR1 improves renal function after I/R associated with a significant reduction in cell apoptosis and inflammatory responses, which may be related to p38 and nuclear factor kappaB inhibition.

The effect of tetramethylpyrazine on hydrogen peroxide-induced oxidative damage in human umbilical vein endothelial cells

Tetramethylpyrazine has been widely used in traditional Chinese medicine to treat cardiovascular diseases such as atherosclerosis and hypertension. The underlying mechanism of cardioprotective effects, however, remains to be elucidated. Here, using human umbilical vein endothelial cells (HUVECs), we have assessed the protective effect of tetramethylpyrazine on H(2)O(2)-induced oxidative damage. After pre-incubation with tetramethylpyrazine (50, 100 and 150 microg/ml) for 24 hr., viability loss in H(2)O(2)-induced HUVECs (76.5% of the control level, p < 0.05, at 400 microM of H(2)O(2) for 12 hr.) was restored in a concentration-dependent manner, and the maximal recovery (88.7% of the control level, p < 0.05) was achieved with tetramethylpyrazine at 150 microg/ml. The production of reactive oxygen species was suppressed by measuring fluorescent intensity of 2',7'-dichorofluorescein (83.1% of the H(2)O(2)-treated group, p < 0.05, at 150 microg/ml of tetramethylpyrazine). Tetramethylpyrazine also increased activities of superoxide dismutase and glutathione peroxidase (144.1% and 118.3% of the H(2)O(2)-treated group, respectively, p < 0.05, at 150 microg/ml of tetramethylpyrazine). In addition, tetramethylpyrazine reduced levels of malonaldehyde, intracellular nitric oxide and nitric oxide synthase (83.8%, 91.2% and 78.7% of the H(2)O(2)-treated group, respectively, p < 0.05, at 150 microg/ml of tetramethylpyrazine). Furthermore, pre-incubation of tetramethylpyrazine with HUVECs for 24 hr. resulted in reduction of apoptosis and removal of cell cycle arrest in the S phase (56.6% and 59.7% of the H(2)O(2)-treated group, respectively, p < 0.01, at 150 microg/ml of tetramethylpyrazine). Altogether, these results suggest that tetramethylpyrazine has a protective effect on H(2)O(2)-induced oxidative damage in HUVECs due to its antioxidant and antiapoptotic properties.

Effect of dexmedetomidine on ischemia-reperfusion injury in rat kidney: a histopathologic study

Ischemia-reperfusion (I-R) injury remains the leading cause of acute renal failure. The purpose of this experimental study was to determine the role of dexmedetomidine on histologic alterations induced by renal I-R in rats. In the present study, thirty male Sprague-Dawley rats weighing 200-220 g were randomly assigned into three groups: the sham-control group (group 1, n = 10), the R/untreated group (group 2, n = 10), and the I-R/dexmedetomidine-treated group (group 3, n = 10). For group one, we performed a sham operation. The abdomen was dissected, the right kidney was harvested, and then the left renal pedicle exposed. Renal clamping was not applied. For group 2, rats underwent left renal ischemia for 60 minutes followed by reperfusion for 45 minutes. For group 3, the same surgical procedure as in group 2 was performed, and dexmedetomidine (100 microg/kg, intraperitoneal) was administrated at the starting time of reperfusion. The rats were sacrificed after reperfusion, and the kidney tissue was harvested. The histopathological score in the kidney of the I-R/dexmedetomidine-treated group rats was significantly lower than that of I-R/untreated group rats. This score in I-R/untreated group rats was higher than the other two groups, which was statistically significant. In the I-R/untreated group rats, kidneys of untreated ischemia rats showed tubular cell swelling, cellular vacuolization, pyknotic nuclei, medullary congestion, and moderate to severe necrosis. Treatment with dexmedetomidine shows normal glomeruli and slight edema of the tubular cells. These findings provide the first evidence that dexmedetomidine can reduce the renal injury caused by I-R of the kidney, and may be useful in enhancing the tolerance of the kidney against renal injury.

The protective mechanism of ligustrazine against renal ischemia/reperfusion injury

BACKGROUND

Ischemia/reperfusion (I/R) injury is unavoidable in renal transplantation, and represents an additional risk factor for the late renal allograft failure. Our study focused on the effects of ligustrazine on oxidative stress, apoptosis, neutrophils recruitment, the expression of proinflammatory mediators and adhesion molecules caused by renal I/R injury.

MATERIALS AND METHODS

Renal warm I/R was induced in male C57BL/6 mice by clamping the left renal artery and vein non-traumatically. Group I was sham-operated animals; group II, nontreated animals; and group III, ligustrazine-treated animals (80 mg/kg, i.p. 30 min before I/R). Mice were sacrificed 4 and 24h post reperfusion. The effects of ligustrazine on oxidative stress, neutrophils recruitment, proinflammatory mediators, and adhesion molecules caused by renal I/R injury were assayed.

RESULTS

Ligustrazine pretreatment attenuated dramatically the injuries in mice kidneys caused by warm I/R (histological scores of untreated versus treated, 4.2 ± 0.4 versus 0.9 ± 0.3; P<0.01). Administration of ligustrazine significantly reduced myeloperoxidase (MPO) activity by 38.6% and decreased malondialdehye (MDA) level by 19.2%, while superoxide dismutase (SOD) activity increased by 39.6% (P<0.01), suggesting an effective reduction of oxidative stress following ligustrazine treatment. Moreover, ligustrazine also inhibited cell apoptosis, abrogated neutrophils recruitment, and suppressed the over expression of TNF-α and ICAM-1.

CONCLUSIONS

In conclusion, ligustrazine protects murine kidney from warm ischemia/reperfusion injury, probably via reducing oxidative stress, inhibiting cell apoptosis, decreasing neutrophils infiltration, and suppressing the overexpression of TNF-α and ICAM-1 levels.

Protective effects of ligustrazine on cisplatin-induced oxidative stress, apoptosis and nephrotoxicity in rats

Cisplatin is an effective agent against various solid tumors. However, its nephrotoxicity been reported to be a dose-limiting factor for treating various types of tumors. The aim of this study was to determine the protective effects of ligustrazine on cisplatin-induced nephrotoxicity through tissue oxidant/antioxidant parameters, light microscopic evaluation, and tubular apoptosis in rats. Ligustrazine was administered in doses of 50 and 100mg/kg/day intraperitoneally (i.p.), for 7 consecutive days, starting 2 days before a single intraveneous dose of cisplatin (8mg/kg). Results revealed that treatment with cisplatin alone caused significant changes in the levels of urinary protein, urinary N-acetyl-beta-d-glucosaminidase, serum creatinine, blood urea nitrogen, and kidneys histopathological damages. All the aforementioned changes were effectively attenuated by ligustrazine. In addition, cisplatin caused increases in the levels of malondialdehyde, nitric oxide, nitric oxide synthase and decreases in the levels of reduced glutathione, glutathione-S-transferase, superoxide dismutase. These changes were restored to near normal levels by ligustrazine at 100mg/kg. In conclusion, ligustrazine has dose dependent protective effects against cisplatin-induced renal tubular toxicity.

Amelioration of Cisplatin-Induced Nephrotoxicity in Rats by Tetramethylpyrazine, a Major Constituent of the Chinese Herb Ligusticum wallichi

Nephrotoxicity of the anticancer drug, cisplatin (CP) involves enhanced renal generation of reactive oxygen metabolites and lipid peroxidation caused by decreased levels of antioxidants and antioxidant enzymes. Tetramethylpyrazine (TMP) is known to act as a strong antioxidant. Therefore, in the present work, we aimed at testing the possible protective or palliative effect of TMP on CP nephrotoxicity in rats. TMP was given orally at a dose of 80 mg · kg− 1 · day− 1 for 7 days. Some of these rats were given a single intraperitoneal injection of CP (or vehicle) at a dose of 6 mg/kg on Day 6 of treatment. Animals were sacrificed 6 days after CP (or vehicle) treatment, and blood, urine, and kidneys were obtained. Nephrotoxicity was assessed biochemically by measuring creatinine and urea in serum, reduced glutathione (GSH) concentration in renal cortex, by urinalysis, and histopathologically by light microscopy. CP significantly increased the concentration of urea and creatinine ( P < 0.05) by about 128% and 170%, respectively; increased urine volume and N-acetyl-β-D-glucosaminidase (NAG) activity; and significantly decreased osmolality and protein concentrations. CP treatment reduced GSH by about 34% ( P < 0.05) and superoxide dismutase (SOD) and total antioxidant activity (TOX) by about 28% and 21%, respectively ( P < 0.05). TMP pretreatment significantly mitigated all of these effects. Sections from saline- and TMP-treated rats showed apparently normal proximal tubules. However, kidneys of CP-treated rats had a moderate degree of necrosis. This was markedly reduced when CP was given after pretreatment with TMP. CP cortical concentration was not significantly altered by TMP treatment. The results suggest that TMP ameliorated the histological, physiological, and biochemical indices of nephrotoxicity in rats. Pending further pharmacological and toxicological studies, TMP may potentially be useful as a nephroprotective agent.

Anti-apoptotic and neuroprotective effects of Tetramethylpyrazine following subarachnoid hemorrhage in rats

This study was designed to explore the effects of Tetramethylpyrazine on cerebral vasospasm and early brain injury and its underlying mechanisms after experimental SAH in rats. Male Sprague-Dawley rats (n=164) were allocated randomly to SAH+TMP, SAH+vehicle (sodium chloride), or sham-operated group. The SAH model was induced through perforating internal carotid artery. TMP (30 mg/kg) or the vehicle was injected via vena caudalis 60 min before the perforation. Mortality, neurological scores, water content of brain and cerebral vasospasm were recorded at 24 h after SAH. Apoptosis of cerebral cortex was determined by TUNEL staining; caspase-3, bax and bcl-2 by Western blotting; P53 expression by immunohistochemical staining. TMP administrated in advance improved neurological scores, ameliorated cerebral edema and cerebral vasospasm. TUNEL-positive cells were reduced significantly in TMP-treated group. P53 was not found significantly different between TMP-treated and vehicle-treated group, while P53 positive cells were markedly higher in SAH group than that in sham-operated group. Cleaved caspase-3 protein was decreased significantly in TMP-treated group, while bax, bcl-2 protein expression did not differ statistically among the three groups. In conclusion, TMP ameliorated cerebral vasospasm and early brain injury after experimental SAH in rats. The underlying mechanisms may be partly related to inhibition of caspase-3 dependent proapoptosis pathway.