Tribulosin protects rat hearts from ischemia/reperfusion injury

Natural products as anthelmintics: safeguarding animal health

Covering literature to December 2022This review provides a comprehensive account of all natural products (500 compounds, including 17 semi-synthetic derivatives) described in the primary literature up to December 2022, reported to be capable of inhibiting the egg hatching, motility, larval development and/or the survival of helminths (i.e., nematodes, flukes and tapeworms). These parasitic worms infect and compromise the health and welfare, productivity and lives of commercial livestock (i.e., sheep, cattle, horses, pigs, poultry and fish), companion animals (i.e., dogs and cats) and other high value, endangered and/or exotic animals. Attention is given to chemical structures, as well as source organisms and anthelmintic properties, including the nature of bioassay target species, in vivo animal hosts, and measures of potency.

Traditional chinese medicine to prevent and treat diabetic erectile dysfunction

Diabetic erectile dysfunction (DED) is one of the most common complications of diabetes mellitus. However, current therapeutics have no satisfactory effect on DED. In recent years, traditional Chinese medicine (TCM) has shown good effects against DED. By now, several clinical trials have been conducted to study the effect of TCM in treating DED; yet, the underlying mechanism is not fully investigated. Therefore, in this review, we briefly summarized the pathophysiological mechanism of DED and reviewed the published clinical trials on the treatment of DED by TCM. Then, the therapeutic potential of TCM and the underlying mechanisms whereby TCM exerts protective effects were summarized. We concluded that TCM is more effective than chemical drugs in treating DED by targeting multiple signaling pathways, including those involved in oxidation, apoptosis, atherosclerosis, and endothelial function. However, the major limitation in the application of TCM against DED is the lack of a large-scale, multicenter, randomized, and controlled clinical trial on the therapeutic effect, and the underlying pharmaceutical mechanisms also need further investigation. Despite these limitations, clinical trials and further experimental studies will enhance our understanding of the mechanisms modulated by TCM and promote the widespread application of TCM to treat DED.

Effects of Tribulus terrestris L. on Sport and Health Biomarkers in Physically Active Adult Males: A Systematic Review

Tribulus terrestris L. (TT) is a plant used in traditional Chinese medicine, Ayurvedic medicine, and sports nutrition to improve health and performance. However, no conclusive evidence exists about the potential beneficial effects of TT on sport and health biomarkers in physically active adults. Based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, and the modified McMaster Critical Review Form for methodological quality assessment, we systematically reviewed studies indexed in Web of Science, Scopus, and PubMed, to assess the effects of TT on immunological, hematological, biochemical, renal, lipidic, hormonal behavior, and anti-inflammatory response in physically active adult males. Among 340 records identified in the search, a total of 7 studies met the inclusion and exclusion criteria. Overall, participants supplemented with TT displayed significant improvements in lipid profile. Inflammatory and hematological biomarkers showed moderate beneficial effects with no significant changes on renal biomarkers. No positive effects were observed on the immune system response. Additionally, no TT-induced toxicity was reported. In conclusion, there was no clear evidence of the beneficial effects of TT supplementation on muscle damage markers and hormonal behavior. More studies are needed to confirm the benefits of TT due to the limited number of studies available in the current literature.

Synchronized resistance training and bioactive herbal compounds of Tribulus Terrestris reverse the disruptive influence of Stanozolol

Androgenic-Anabolic Steroids (AAS) consumption may have irreversible effects on athletes' hearts. The beneficial effects of Tribulus Terrestris (TT) have been shown to reduce cardiovascular risks through disruption in apoptosome complex construction. Therefore, this study aimed to investigate the effect of eight weeks of resistance training (RT) with TT consumption in the heart tissue of rats exposed to Stanozolol. Thirty-five male rats were divided into seven groups, Control group, Stanozolol (ST), ST + 100 mg/kg TT, ST + 50 mg/kg TT, RT + ST, RT + ST + 100 mg/kg TT, and RT + ST + 50 mg/kg TT. Differential genes expression was measured by q-RT-PCR. Artificial intelligence highlighted apoptosis pathways as a vital process in cardiovascular risks. Hence, we estimated the binding affinity of chemical and bioactive molecules on the cut point hub gene by pharmacophore modeling and molecular docking. Moreover, ST increased IL-6, Cat, Aif-1, and Caspase-9. 100 mg/kg TT has a more favorable effect than 50 mg/kg T. Also, RT with TT had interactive effects on reducing IL-6, Cat, Aif-1, and Caspase-9. RT and TT consumption seemed to synergistically reduce the apoptotic pathway markers in the heart tissue of rats exposed to the supra-physiologic dose of ST. Moreover, TT could be added to supplements and sports drink to increase an athlete's performance.

In-silico efficacy of potential phytomolecules from Ayurvedic herbs as an adjuvant therapy in management of COVID-19

The recent COVID-19 outbreak caused by SARS-CoV-2 virus has sparked a new spectrum of investigations, research and studies in multifarious directions. Efforts are being made around the world for discovery of effective vaccines/drugs against COVID-19. In this context, Ayurveda, an alternative traditional system of medicine in India may work as an adjuvant therapy in compromised patients. We selected 40 herbal leads on the basis of their traditional applications. The phytomolecules from these leads were further screened through in-silico molecular docking against two main targets of SARS-CoV-2 i.e. the spike protein (S; structural protein) and the main protease (M^PRO; non-structural protein). Out of the selected 40, 12 phytomolecules were able to block or stabilize the major functional sites of the main protease and spike protein. Among these, Ginsenoside, Glycyrrhizic acid, Hespiridin and Tribulosin exhibited high binding energy with both main protease and spike protein. Etoposide showed good binding energy only with Spike protein and Teniposide had high binding energy only with main protease. The above phytocompounds showed promising binding efficiency with target proteins indicating their possible applications against SARS-CoV-2. However, these findings need to be validated through in vitro and in vivo experiments with above mentioned potential molecules as candidate drugs for the management of COVID-19. In addition, there is an opportunity for the development of formulations through different permutations and combinations of these phytomolecules to harness their synergistic potential.

Optimization of ultrasound extraction of Tribulus terrestris L. leaves saponins and their HPLC-DAD-ESI-MSn profiling, anti-inflammatory activity and mechanism in vitro and in vivo

ETHNOPHARMACOLOGICAL RELEVANCE

Tribulus terrestris L., as an annual herb plant from Zygophyllaceae, exhibits many biological activities, and its main chemical constituents are saponins. However, the extraction process, chemical compositions, anti-inflammatory effect and mechanism of total saponins from Tribulus terrestris L. leaves are still unclear.

AIM OF THE STUDY

The present study extensively evaluated the extraction process, major components, anti-inflammatory action and mechanism of Tribulus terrestris L. leaves saponins.

MATERIALS AND METHODS

The ultrasonic extraction and response surface methods were adopted for optimization of extraction technology of total saponins from Tribulus terrestris L. leaves, and its compositions were detected with LC-MSⁿ method. The anti-inflammatory activity of total saponins was studied by lipopolysaccharide induced RAW 264.7 cells and acute lung injury mice models.

RESULTS

The ultrasonic extraction parameters of saponins fraction, including ethanol concentration 30%, extraction time 55 min, ratio of solvent to material 35:1 ml/g and extraction temperature 46 °C, were screened by response surface method with the extracting rate 5.49%, and thirty compositions were detected with LC-MSⁿ method. Moreover, saponins fraction can play a stronger anti-inflammatory effect by reducing the phagocytic activity and pulmonary edema, and protection of morphology of RAW 264.7 cells and lung tissues, and decreasing the content of NO and TNF-α. Moreover, it was revealed that total saponins extract can exert the anti-inflammatory action by the inhibition of the activation of the TLR4-TRAF6-NF-κB signalling pathway.

CONCLUSION

These studies imply that Tribulus terrestris L. leaves saponins may be an important anti-inflammatory drug in clinic.

The roles of PKC-δ and PKC-ε in myocardial ischemia/reperfusion injury

Ischemia and reperfusion (I/R) cause a reduction in arterial blood supply to tissues, followed by the restoration of perfusion and consequent reoxygenation. The reestablishment of blood flow triggers further damage to ischemic tissue through reactive oxygen species (ROS) accumulation, interference with cellular ion homeostasis, opening of mitochondrial permeability transition pores (mPTPs) and promotion of cell death (apoptosis or necrosis). PKC-δ and PKC-ε, belonging to a family of serine/threonine kinases, have been demonstrated to play important roles during I/R injury in cardiovascular diseases. However, the cardioprotective mechanisms of PKC-δ and PKC-ε in I/R injury have not been elaborated until now. This article discusses the roles of PKC-δ and PKC-ε during myocardial I/R in redox regulation (redox signaling and oxidative stress), cell death (apoptosis and necrosis), Ca²⁺ overload, and mitochondrial dysfunction.

Anti-Apoptotic Effects of Resistance Training and Tribulus Terrestris Consumption in the Heart Tissue of Rats Exposed to Stanozolol

Objective

Nowadays, the use of energetic substances has become a complex problem in sports, such that the role of anabolic-androgenic steroids is undeniable. This study aimed to investigate the antiapoptotic effect of resistance training and Tribulus terrestris in the heart tissue of rats exposed to stanozolol.

Materials and Methods

35 rats divided into 7 groups including (1) sham, (2) stanozolol-treated, (3) stanozolol+50 mg/kg Tribulus terrestris-treated, (4) stanozolol+100 mg/kg Tribulus terrestris-treated, (5) stanozolol+resistance training-treated, (6) stanozolol+resistance training+50 mg/kg Tribulus terrestris-treated, and (7) stanozolol+resistance training+100 mg/kg Tribulus terrestris-treated. During 8 weeks, groups 2-7 received 5 mg/kg stanozolol per day peritoneally; groups 5-7 performed resistance training for 3 sessions per week; and groups 3, 4, 6 and 7 received daily doses of Tribulus terrestris peritoneally.

Results

Stanozolol administration significantly increased the BAX, BCL-2, P53, and caspase 3 and BAX/BCL-2 ratio (P < .001). Resistance training, 100 mg/kg Tribulus terrestris administration, 50 mg/kg Tribulus terrestris administration, resistance training+100 mg/kg Tribulus terrestris administration, and resistance training+50 mg/kg Tribulus terrestris administration significantly decreased BAX, BCL-2, P53, and caspase 3 levels and BAX/BCL-2 ratio (P < .001); however, stanozolol+resistance training+100 mg/kg Tribulus terrestris administration caused more decrease than stanozolol+resistance training+50 mg/kg Tribulus terrestris administration in BAX (P < .001).

Conclusion

Resistance training and Tribulus terrestris administration alone appear to have antiapoptotic effects; however, resistance training combined with Tribulus terrestris administration, especially at higher doses, have more desirable effects than resistance training or Tribulus terrestris administration alone on the apoptosis markers.

Integrating metabolomics and network pharmacology to explore the protective effect of gross saponins of Tribulus terrestris L. fruit against ischemic stroke in rat

ETHNOPHARMACOLOGICAL RELEVANCE

Tribulus terrestris L. belongs to the family Zygophyllaceae and has been widely used as a folk medicine for a long history in Asian countries. Gross saponins of Tribulus terrestris L. fruit (GSTTF) has an obvious neuroprotective effect on the treatment of ischemic stroke, but its potential therapeutic mechanisms have not been thoroughly studied.

AIM OF THE STUDY

To investigate the protective effect of GSTTF against ischemic stroke in rat.

MATERIALS AND METHODS

The combination of metabolomics and network pharmacology analysis was applied to investigate the protective effects of GSTTF on ischemic stroke and its putative mechanism. The related pathway of the biomarkers highlighted from metabolomics analysis was explored, then the possible targets of GSTTF were further revealed by network pharmacology analysis. Molecular docking was conducted to investigate the interaction between the active compound and target protein.

RESULTS

Metabolomics analysis showed that metabolic disturbances were observed in serum for the rats in middle cerebral artery occlusion (MCAO). These MCAO-induced deviations in serum metabolism can be reversely changed by GSTTF via metabolic pathways regulation. Twenty-four proteins with the connectivity degree larger than 15 were selected by the network pharmacology analysis, which are considered as the possible therapeutic targets of the GSTTF against ischemic stroke. The results of molecular docking showed that the active compounds were capable of binding to the representative potential targets HSD11B1 and AR, respectively. And the docking mode of two compounds with the lowest binding energy to their target protein was illustrated by the ribbon binding map.

CONCLUSION

The present study combines metabolomics and network pharmacology analysis to investigate the mechanism of MCAO-induced ischemic stroke and reveal the efficiency and possible mechanisms of GSTTF for ischemic stroke. Further studies on the bioactive saponin as well as their synergistic action on ischemic stroke will be conducted to better reveal the underlying mechanisms.

Histopathological evaluation of the role of negative electrical charge on renal ischemia/reperfusion injuries on brain and heart tissues in rat

This study was performed to evaluate the role of electroacupuncture on kidney 1 (Ki1) acupoint to prevent the heart and brain injury following ischemia/reperfusion of both kidneys. 24 Sprague Dawley rats were randomly assigned into four equal groups. In the treatment 1 group, following anesthesia, acupuncture needles were inserted on Ki1 on the palm of both hindlimbs and connected to electroacupuncture unit for a 3.00 Hz direct current, 1 hr before surgery until the end of surgery. In treatment two groups, the electroacupuncture was also performed 48 and 24 hr before the operation, with the same protocol as treatment 1. Control 1 and control 2 groups had the same procedures like the treatment ones, except for acupuncture. Immediately after reperfusion, the samples of brains and hearts were taken and prepared for microscopic examination. Histopathological study of the heart in the control and treatment groups showed the breakage of myofibrils, hyaline necrosis, edema and disorganization of myocytes. The severity of cardiac lesions was decreased in both treatment groups in comparison with the controls. Brain in control and treatment groups showed ischemic necrosis, disorganization of the neurons in the hippocampus, and edema. The severity of lesions was reduced in the treatment groups and showed a significant difference between the control and treatment 1. It could be concluded that electroacupuncture on the Ki1 point could reduce the severity of damages induced by renal ischemia/reperfusion in the remote organs of the heart and brain.

Extraction technology, component analysis, antioxidant, antibacterial, analgesic and anti-inflammatory activities of flavonoids fraction from Tribulus terrestris L. leaves

Research on the extraction technology, component analysis, and antioxidant, antibacterial, analgesic and anti-inflammatory activities of flavonoids fraction from Tribulus terrestris L. leaves was carried out. The extraction process was optimized by response surface method, and the maximum yield 0.27% for flavonoids fraction was achieved with concentration of ethanol solution 25.87%, ratio of solvent to material 30:1 ml/g, and ultrasonic extraction time 27.93 min. Moreover, 14 compositions were identified separately from flavonoids fraction by HPLC-DAD-ESI-MS². In addition, flavonoids fraction exhibited a better antioxidant activity demonstrated by assays of ABTS, DPPH radical scavenging activity and ferric reducing antioxidant power activity. Furthermore, the antibacterial, analgesic and anti-inflammatory activities of flavonoids fraction were also proved to be stronger. Therefore, the present findings suggest that flavonoids fraction from Tribulus terrestris L. leaves can be a very interesting candidate for the research and development of natural and healthy herbal medicine for the pharmaceutical and food industries.

Chemical Constituents, Biological Properties, and Uses of Tribulus terrestris: A Review

Tribulus terrestris L. (TT) (puncturevine) is a common weed that grows in many countries worldwide and in some places is considered as a noxious weed. The plant has been used in traditional Chinese and Indian medicines and is now considered as one of the most popular aphrodisiacs. It is known for its healing properties for sexual difficulties, impotence, and human and animal hormonal imbalance. It is also used as a sexual booster. Because of the plant’s active substances that can be used for curing sexual and other disorders, interest in it is increasing, and it is currently one of the most studied medicinal plants. The products and preparations manufactured from the aboveground plant parts are especially popular among athletes and people with health issues and diseases such as hormonal imbalance, sexual problems, heart problems, and various kidney and skin diseases. The aim of this review is a comprehensive and critical assessment of the scientific publications involving TT, with special reference to its chemical constituents and biological properties that may facilitate current understanding and future studies of this fascinating plant species. The objectives of this review were (1) to find knowledge gaps, (2) to discuss critically relevant publications and issues with materials and methods that may be prerequisites for contradictory results, and (3) to identify research and development areas. It was found that some of the studies on TT extracts as aphrodisiacs are controversial. A significant number of research publications claim that TT extracts and nutritional supplements containing TT improve muscle tone, have a common biostimulating effect, and improve spermogenesis. However, there are a growing number of publications that dispute these claims, as there are no empirical data on commonly accepted mechanisms of action. The main biologically active substances in TT are steroidal saponins, flavonoids, alkaloids, and lignan amides, the most studied being the steroidal saponins. Multiyear data on the metabolic profile of the species are generally lacking. There are a variety of methods used for extracting plant material, differences in methodologies and saponin analyses, and scientific instruments that were used. Lack of common standards could be a reason for differences in the pharmacological activity and composition of the TT preparations. Development of standard procedures and methods for collection of plant material and analyses are recommended. Selection and breeding efforts and agronomic studies of promising clones of TT would need to be conducted in order to develop TT as a new crop. This will provide consistency of supply and quality of the feedstock for the pharmaceutical industry and could provide a new cash crop for growers.

Gross saponin of Tribulus terrestris improves erectile dysfunction in type 2 diabetic rats by repairing the endothelial function of the penile corpus cavernosum

OBJECTIVE

To investigate the effect of gross saponins of Tribulus terrestris (GSTT) on erectile function in rats resulting from type 2 diabetes mellitus (T2DMED).

METHODS

The T2DMED model was constructed by high-fat and high-sugar feeding and streptozotocin injection. After 4 weeks of GSTT intervention. Intracavernous pressure (ICP) and mean arterial pressure (MAP) were measured in each group. The level of nitric oxide (NO) in the cavernous tissue was detected using the nitrate reductase method. The production of reactive oxygen species (ROS) was detected using DHE fluorescent probe detection. Cyclic adenosine monophosphate (cGMP) level was detected by enzyme-linked immunosorbent assay, and endothelial nitric oxide synthase (eNOS) was detected using immunohistochemistry. Masson staining was used to detect the cavernosal smooth muscle/collagen ratio. Apoptosis in endothelial cells was measured using TUNEL. Western blotting method to detect the protein expression level of eNOS, TIMP-1, cleaved caspase 3, and cleaved caspase 9.

RESULTS

After treatment, the ICP and ICP/MAP values of the GSTT were significantly higher than those of the T2DMED group (P<0.05). Unlike the T2DMED group, the GSTT group showed significantly increased NO levels (P<0.05) and decreased ROS levels (P<0.05). There was no significant difference between the GSTT group and the sildenafil group in increasing cGMP levels (P>0.05), and the mixed group had higher levels than these two groups (P<0.05). Immunohistochemistry and Western blotting showed that the expression of eNOS in the GSTT was significantly higher than that in the T2DMED groups (P<0.05). Masson staining showed that the smooth muscle/collagen ratio of the GSTT group was significantly higher than that of the T2DMED groups (P<0.05), the expression of TIMP-1 was lower than that of T2DMED group (P<0.05). TUNEL assay showed that the apoptotic index and cleaved caspase 3 and cleaved caspase 9 expression level of GSTT group were lower than that of the T2DMED group (P<0.05).

CONCLUSION

GSTT can protect T2DMED rats' erectile function by improving penile endothelial function and inhibiting cavernosum fibrosis, inhibiting apoptosis, and is synergistic with sildenafil.

The effect of melatonin on cardio fibrosis in juvenile rats with pressure overload and deregulation of HDACs

The effect of melatonin on juveniles with cardio fibrosis is poorly understood. We investigated whether HDACs participate in the anti-fibrotic processes regulated by melatonin during hypertrophic remodeling. Abdominal aortic constriction (AAC) was employed in juvenile rats resulting in pressure overload-induced ventricular hypertrophy and melatonin was subsequently decreased via continuous light exposure for 5 weeks after surgery. AAC rats displayed an increased cross-sectional area of myocardial fibers and significantly elevated collagen deposition compared to sham-operated rats, as measured by HE and Masson Trichrome staining. Continuous light exposure following surgery exacerbated the increase in the cross-sectional area of myocardial fibers. The expression of HDAC1, HDAC2, HDAC3, HDAC4 and HDAC6 genes were all significantly enhanced in AAC rats with light exposure relative to the other rats. Moreover, the protein level of TNF-α was also upregulated in the AAC light exposure groups when compared with the sham. However, Smad4 protein expression was unchanged in the juveniles' hearts. In contrast, beginning 5 weeks after the operation, the AAC rats were treated with melatonin (10 mg/kg, intraperitoneal injection every evening) or vehicle 4 weeks, and sham rats were given vehicle. The changes in the histological measures of cardio fibrosis and the gene expressions of HDAC1, HDAC2, HDAC3, HDAC4 and HDAC6 were attenuated by melatonin administration. The results reveal that melatonin plays a role in the development of cardio fibrosis and the expression of HDAC1, HDAC2, HDAC3, HDAC4 and HDAC6 in cardiomyocytes.

Saponins of Tribulus terrestris attenuated neuropathic pain induced with vincristine through central and peripheral mechanism

The study comprises exploring the effects of saponins from Tribulus terrestris (TT) in attenuating the neuropathic pain caused by vincristine (100 μg/ml i.p.) for 10 days (in two 5 day cycles with 2 days pause). Mechanical hyperalgesia and allodynia were assessed by Randall-Sellitto and electronic von Frey tests, respectively. Chemical- induced nociception was assessed by formalin test. Neurophysiological effect of the extract was evaluated by recording sciatic functional index (SFI) on the test days (7, 10, 14, and 21) and sciatic nerve conduction velocity test (SNCV) on the last day. Inflammatory mediators (TNF-α, IL-1β, and IL-6) in both sciatic nerve and brain and brain neurotransmitters, glutamate and aspartate, were measured to support the behavioral response. The saponins of TT-treated group were found to be effective in the behavioral experiments, implying its activity both centrally and peripherally in attenuating pain. The inflammatory mediators in both sciatic nerve and brain (TNF-α, IL-1β, and IL-6) were found to be attenuated with TT saponin treatment in comparison to vincristine-treated group, indicating its anti-inflammatory property. The excitatory neurotransmitters, L-glutamic acid and L-aspartic acid, were also found to be attenuated with TT saponins, implying restoration of neuronal damage and synaptic activity caused by high amount of glutamate due to excess TNF-α in brain and reversing the nociceptive threshold lowered due to aspartate. Thus, TT(S) is peripherally and centrally active in lowering the inflammatory mediators, reversing the neuronal damage and increasing the nociceptive threshold caused due to peripheral neuropathy.

Structural characteristics, bioavailability and cardioprotective potential of saponins

Cardiovascular diseases are the leading cause of death, accounting about 31% deaths globally in 2012. The major risk factors causing cardiovascular diseases are coronary atherosclerosis, hyperlipidemia, myocardial infarction, and stroke. The dominating cause of cardiovascular diseases is accredited to our modern lifestyle and diet. Medicinal plants have been used for the prevention and treatment of cardiovascular diseases from centuries. The in built chirality and chemical space of natural products have been playing an important role in providing leads and templates for pharmacophore synthesis. This review highlights one of the important naturally occurring class saponins and their role in cardioprotection along with structural characteristics and pharmacological effects such as antioxidant, Ca²⁺ ion regulation, antiapoptotic, antiatherosclerosis, antihyperlipidemic, hypocholesterolemic, angiogenic, vasodilatory, and hypotensive. The characteristic cholesterol lowering, hemolytic, and anticoagulant properties of the saponins prompted us to select as one of the natural products class for cardioprotection. This review covers the most updated information on saponins related to their cardioprotective effects, mechanism of action, bioavailability, and structure activity relationship.

Untargeted metabolomics analysis of ischemia-reperfusion-injured hearts ex vivo from sedentary and exercise-trained rats

INTRODUCTION

The effects of exercise on the heart and its resistance to disease are well-documented. Recent studies have identified that exercise-induced resistance to arrhythmia is due to the preservation of mitochondrial membrane potential.

OBJECTIVES

To identify novel metabolic changes that occur parallel to these mitochondrial alterations, we performed non-targeted metabolomics analysis on hearts from sedentary and exercise-trained rats challenged with isolated heart ischemia-reperfusion injury (I/R).

METHODS

Eight-week old Sprague-Dawley rats were treadmill trained 5 days/week for 6 weeks (exercise duration and intensity progressively increased to 1 h at 30 m/min up a 10.5% incline, 75-80% VO_2max). The recovery of pre-ischemic function for sedentary rat hearts was 28.8 ± 5.4% (N = 12) compared to exercise trained hearts, which recovered 51.9% ± 5.7 (N = 14) (p < 0.001).

RESULTS

Non-targeted GC-MS metabolomics analysis of (1) sedentary rat hearts; (2) exercise-trained rat hearts; (3) sedentary rat hearts challenged with global ischemia-reperfusion (I/R) injury; and (4) exercise-trained rat hearts challenged with global I/R (10/group) revealed 15 statistically significant metabolites between groups by ANOVA using Metaboanalyst (p < 0.001). Enrichment analysis of these metabolites for pathway-associated metabolic sets indicated a > 10-fold enrichment for ammonia recycling and protein biosynthesis. Subsequent comparison of the sedentary hearts post-I/R and exercise-trained hearts post-I/R further identified significant differences in three metabolites (oleic acid, pantothenic acid, and campesterol) related to pantothenate and CoA biosynthesis (p ≤ 1.24E-05, FDR ≤ 5.07E-4).

CONCLUSIONS

These studies shed light on novel mechanisms in which exercise-induced cardioprotection occurs in I/R that complement both the mitochondrial stabilization and antioxidant mechanisms recently described. These findings also link protein synthesis and protein degradation (protein quality control mechanisms) with exercise-linked cardioprotection and mitochondrial susceptibility for the first time in cardiac I/R.

Cardiac Protection of Valsartan on Juvenile Rats with Heart Failure by Inhibiting Activity of CaMKII via Attenuating Phosphorylation

Background. This study was undertaken to determine relative contributions of phosphorylation and oxidation to the increased activity of calcium/calmodulin-stimulated protein kinase II (CaMKII) in juveniles with cardiac myocyte dysfunction due to increased pressure overload. Methods. Juvenile rats underwent abdominal aortic constriction to induce heart failure. Four weeks after surgery, rats were then randomly divided into two groups: one group given valsartan (HF + Val) and the other group given placebo (HF + PBO). Simultaneously, the sham-operated rats were randomly given valsartan (Sham + Val) or placebo (Sham + PBO). After 4 weeks of treatment, Western blot analysis was employed to quantify CaMKII and relative calcium handling proteins (RyR2 and PLN) in all groups. Results. The deteriorated cardiac function was reversed by valsartan treatment. In ventricular muscle cells of group HF + PBO, Thr287 phosphorylation of CaMKII and S2808 phosphorylation of RyR2 and PLN were increased and S16 phosphorylation of PLN was decreased compared to the other groups, while Met281 oxidation was not significantly elevated. In addition, these changes in the expression of calcium handling proteins were ameliorated by valsartan administration. Conclusions. The phosphorylation of Thr286 is associated with the early activation of CaMKII rather than the oxidation of Met281.

Gypenosides alleviate myocardial ischemia-reperfusion injury via attenuation of oxidative stress and preservation of mitochondrial function in rat heart

Gypenosides (GP) are the predominant components of Gynostemma pentaphyllum, a Chinese herb medicine that has been widely used for the treatment of chronic inflammation, hyperlipidemia, and cardiovascular disease. GP has been demonstrated to exert protective effects on the liver and brain against ischemia-reperfusion (I/R) injury, yet whether it is beneficial to the heart during myocardial I/R is unclear. In this study, we demonstrate that pre-treatment with GP dose-dependently limits infarct size, alleviates I/R-induced pathological changes in the myocardium, and preserves left ventricular function in a rat model of cardiac I/R injury. In addition, GP pre-treatment reduces oxidative stress and protects the intracellular antioxidant machinery in the myocardium. Further, we show that the cardioprotective effect of GP is associated with the preservation of mitochondrial function in the cardiomyocytes, as indicated by ATP level, enzymatic activities of complex I, II, and IV on the mitochondrial respiration chain, and the activity of citrate synthase in the citric acid cycle for energy generation. Moreover, GP maintains mitochondrial membrane integrity and inhibits the release of cytochrome c from the mitochondria to the cytosol. The cytoprotective effect of GP is further confirmed in vitro in H9c2 cardiomyoblast cell line with oxygen-glucose deprivation and reperfusion (OGD/R), and the results indicate that GP protects cell viability, reduces oxidative stress, and preserves mitochondrial function. In conclusion, our study suggests that GP may be of clinical value in cytoprotection during acute myocardial infarction and reperfusion.

Damaging effects of hyperglycemia on cardiovascular function: spotlight on glucose metabolic pathways

The incidence of cardiovascular complications associated with hyperglycemia is a growing global health problem. This review discusses the link between hyperglycemia and cardiovascular diseases onset, focusing on the role of recently emerging downstream mediators, namely, oxidative stress and glucose metabolic pathway perturbations. The role of hyperglycemia-mediated activation of nonoxidative glucose pathways (NOGPs) [i.e., the polyol pathway, hexosamine biosynthetic pathway, advanced glycation end products (AGEs), and protein kinase C] in this process is extensively reviewed. The proposal is made that there is a unique interplay between NOGPs and a downstream convergence of detrimental effects that especially affect cardiac endothelial cells, thereby contributing to contractile dysfunction. In this process the AGE pathway emerges as a crucial mediator of hyperglycemia-mediated detrimental effects. In addition, a vicious metabolic cycle is established whereby hyperglycemia-induced NOGPs further fuel their own activation by generating even more oxidative stress, thereby exacerbating damaging effects on cardiac function. Thus NOGP inhibition, and particularly that of the AGE pathway, emerges as a novel therapeutic intervention for the treatment of cardiovascular complications such as acute myocardial infarction in the presence hyperglycemia.

Calycosin‑7‑O‑β‑D‑glucoside attenuates ischemia‑reperfusion injury in vivo via activation of the PI3K/Akt pathway

The aim of the present study was to investigate the effects and mechanisms of calycosin‑7‑O‑β‑D‑glucoside (CG) on ischemia‑reperfusion (I/R) injury in vivo. Hemodynamic parameters, including ejection fraction (EF), fractional shortening (FS), left ventricular end‑systolic pressure (LVESP) and left ventricular end‑diastolic pressure (LVEDP) were monitored using an ultrasound system, and infarct size was measured using Evans blue/tetrazolium chloride double staining. The activities of serum creatine kinase (CK), lactate dehydrogenase (LDH) and superoxide dismutase (SOD), and the levels of malondialdehyde (MDA) were determined to assess the degree of myocardial injury and oxidative stress‑induced damage. The protein expression levels of cleaved‑caspase‑3, cleaved‑caspase‑9, phosphorylated (p)‑phosphatidylinositol 3‑kinase (PI3K) p85, PI3K p85, p‑Akt and Akt were determined using western blotting. The results demonstrated that pretreatment with high dose (H)‑CG markedly improved cardiac function, as evidenced by upregulated EF, FS and LVESP, and downregulated LVEDP. In addition, administration of CG resulted in significant decreases in infarct size in the I/R+low dose‑CG and I/R+H‑CG groups, compared with the I/R group. The activities of CK and LDH, and the levels of MDA in the I/R+H‑CG group were reduced, compared with those in the I/R group, whereas SOD activity was elevated. Treatment with CG inhibited the cleavage and activity of caspase‑3 and caspase‑9, and enhanced the phosphorylation of PI3K p85 and Akt. Notably, administration of the PI3K inhibitor, LY294002, markedly lowered the levels of p‑PI3K p85/p‑Akt, and eradicated the inhibitory effects of H‑CG on infarct size, myocardial injury and oxidative stress‑induced damage. Taken together, the results suggested that CG may alleviate I/R injury by activating the PI3K/Akt signaling pathway.

The effects of N-acetylcysteine on cisplatin-induced cardiotoxicity on isolated rat hearts after short-term global ischemia

The aim of this study was to estimate the protective effect of N-acetyl-l-cysteine (NAC) against cisplatin-induced cardiotoxicity under conditions of ischemic-reperfusion injury.

Wistar albino rats were randomly divided into three groups (n = 8): control, cisplatin (5 mg/kg/w, i.p., 5 weeks) and cisplatin + NAC group (cisplatin – 5 mg/kg/w, i.p. and NAC – 500 mg/kg/w, i.p., 5 weeks). Isolated hearts were perfused according to the modified Langendorff technique at constant pressure (70 cmH₂O). Following cardiodynamic parameters were measured: maximum rate of left ventricular pressure development, minimum rate of left ventricular pressure development, left ventricular systolic pressure (SLVP), left ventricular diastolic pressure and heart rate. The ischemic vasodilation episodes were induced by the complete interruption of coronary inflow for 30, 60 and 120 s. The samples of the coronary venous effluent (CVE) were continuously collected during the reperfusion period for determination of coronary flow (CF) rate and oxidative stress markers (H₂O₂, O₂⁻, NO₂⁻ and thiobarbituric acid reactive substances – TBARS).

Cisplatin reduced CF, heart rate and overflow (total, maximal and duration of overflow) during reperfusion, and increased SLVP (under basal conditions and after global ischemias). Cisplatin increased levels of H₂O₂ (under basal conditions), O₂⁻ and TBARS (under basal conditions and after ischemia), but decreased NO₂⁻ levels (during reperfusion) in CVE, and decreased superoxide dismutase and reduced glutathione in serum. NAC attenuated cisplatin-induced changes of cardiodynamic parameters (except CF under basal conditions) and oxidative stress parameters.

Those results suggest that NAC, by decreasing oxidative stress, may be useful in cardioprotection during cisplatin therapy.

Sevoflurane post-conditioning protects isolated rat hearts against ischemia-reperfusion injury via activation of the ERK1/2 pathway

AIM

To investigate the role of extracellular signal-regulated kinases (ERKs) in sevoflurane post-conditioning induced cardioprotection in vitro.

METHODS

Isolated rat hearts were subjected to 30 min ischemia followed by 120 min reperfusion (I/R). Sevoflurane post-conditioning was carried out by administration of O2-enriched gas mixture with 3% sevoflurane (SEVO) for 15 min from the onset of reperfusion. Cardiac functions, myocardial infarct size, myocardial ATP and NAD(+) contents, mitochondrial ultrastructure, and anti-apototic and anti-oncosis protein levels were measured.

RESULTS

Sevoflurane post-conditioning significantly improved the heart function, decreased infarct size and mitochondria damage, and increased myocardial ATP and NAD(+) content in the I/R hearts. Furthermore, sevoflurane post-conditioning significantly increased the levels of p-ERK and p-p70S6K, decreased the levels of porimin, caspase-8, cleaved caspase-3, and cytosolic cytochrome c in the I/R hearts. Co-administration of the ERK1/2 inhibitor PD98059 (20 μmol/L) abolished the sevoflurane-induced protective effects against myocardial I/R.

CONCLUSION

Sevoflurane post-conditioning protects isolated rat hearts against myocardial I/R injury and inhibits cell oncosis and apoptosis via activation of the ERK1/2 pathway.

Phytopharmacological overview of Tribulus terrestris

Tribulus terrestris (family Zygophyllaceae), commonly known as Gokshur or Gokharu or puncture vine, has been used for a long time in both the Indian and Chinese systems of medicine for treatment of various kinds of diseases. Its various parts contain a variety of chemical constituents which are medicinally important, such as flavonoids, flavonol glycosides, steroidal saponins, and alkaloids. It has diuretic, aphrodisiac, antiurolithic, immunomodulatory, antidiabetic, absorption enhancing, hypolipidemic, cardiotonic, central nervous system, hepatoprotective, anti-inflammatory, analgesic, antispasmodic, anticancer, antibacterial, anthelmintic, larvicidal, and anticariogenic activities. For the last few decades or so, extensive research work has been done to prove its biological activities and the pharmacology of its extracts. The aim of this review is to create a database for further investigations of the discovered phytochemical and pharmacological properties of this plant to promote research. This will help in confirmation of its traditional use along with its value-added utility, eventually leading to higher revenues from the plant.

Effect of Tribulus terrestris on Haloperidol-induced Catalepsy in Mice

Haloperidol, an antipsychotic drug, leads to the development of a behavioural state called catalepsy, in which the animal is not able to correct an externally imposed posture. In the present study we have attempted to evaluate the anticataleptic effect of Tribulus terrestris on haloperidol-induced catalepsy in albino mice. Mice were allocated to four groups, each group containing six animals. Both, the test drug, Tribulus terrestris and the standard drug trihexyphenidyl were uniformly suspended in 1% gum acacia solution. Catalepsy was induced in mice with haloperidol (1.0 mg/kg, intraperitoneally). The first group received the vehicle (10 ml/kg, orally), the second group received trihexyphenidyl (10 mg/kg, orally) and the remaining two groups received Tribulus terrestris (100, 200 mg/kg, orally). The animals were assessed after single and repeated dose administration for ten days, 30 min prior to haloperidol, using standard bar test. The result of the present study demonstrates Tribulus terrestris has a protective effect against haloperidol-induced catalepsy, which is comparable to the standard drug used for the same purpose. Our study indicates Tribulus terrestris can be used to prevent haloperidol-induced extrapyramidal side effects.

Effect of a multivitamin preparation supplemented with phytosterol on serum lipids and infarct size in rats fed with normal and high cholesterol diet

Background

Although complex multivitamin products are widely used as dietary supplements to maintain health or as special medical food in certain diseases, the effects of these products were not investigated in hyperlipidemia which is a major risk factor for cardiovascular diseases. Therefore, here we investigated if a preparation developed for human use containing different vitamins, minerals and trace elements enriched with phytosterol (VMTP) affects the severity of experimental hyperlipidemia as well as myocardial ischemia/reperfusion injury.

Methods

Male Wistar rats were fed a normal or cholesterol-enriched (2% cholesterol + 0.25% cholate) diet for 12 weeks to induce hyperlipidemia. From week 8, rats in both groups were fed with a VMTP preparation or placebo for 4 weeks. Serum triglyceride and cholesterol levels were measured at week 0, 8 and 12. At week 12, hearts were isolated, perfused according to Langendorff and subjected to a 30-min coronary occlusion followed by 120 min reperfusion to measure infarct size.

Results

At week 8, cholesterol-fed rats showed significantly higher serum cholesterol level as compared to normal animals, however, serum triglyceride level did not change. VMTP treatment significantly decreased serum cholesterol level in the hyperlipidemic group by week 12 without affecting triglyceride levels. However, VMTP did not show beneficial effect on infarct size. The inflammatory marker hs-CRP and the antioxidant uric acid were also not significantly different.

Conclusions

This is the first demonstration that treatment of hyperlipidemic subjects with a VMTP preparation reduces serum cholesterol, the major risk factor for cardiovascular disease; however, it does not provide cardioprotection.

Quercetin postconditioning attenuates myocardial ischemia/reperfusion injury in rats through the PI3K/Akt pathway

Quercetin (Que), a plant-derived flavonoid, has multiple benefical actions on the cardiovascular system. The current study investigated whether Que postconditioning has any protective effects on myocardial ischemia/reperfusion (I/R) injury in vivo and its potential cardioprotective mechanisms. Male Sprague-Dawley rats were randomly allocated to 5 groups (20 animals/group): sham, I/R, Que postconditioning, Que+LY294002 [a phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathway inhibitor], and LY294002+I/R. I/R was produced by 30-min coronary occlusion followed by 2-h reperfusion. At the end of reperfusion, myocardial infarct size and biochemical changes were compared. Apoptosis was evaluated by both TUNEL staining and measurement of activated caspase-3 immunoreactivity. The phosphorylation of Akt and protein expression of Bcl-2 and Bax were determined by Western blotting. Que postconditioning significantly reduced infarct size and serum levels of creatine kinase and lactate dehydrogenase compared with the I/R group (all P<0.05). Apoptotic cardiomyocytes and caspase-3 immunoreactivity were also suppressed in the Que postconditioning group compared with the I/R group (both P<0.05). Akt phosphorylation and Bcl-2 expression increased after Que postconditioning, but Bax expression decreased. These effects were inhibited by LY294002. The data indicate that Que postconditioning can induce cardioprotection by activating the PI3K/Akt signaling pathway and modulating the expression of Bcl-2 and Bax proteins.

Mangiferin mitigates diabetic cardiomyopathy in streptozotocin-diabetic rats

The purpose of this study was to investigate the cardioprotective effect of mangiferin on diabetic cardiomyopathy (DCM). The DCM model was induced by a high-fat diet and a low dose of streptozotocin. We evaluated the characteristics of DCM by serial echocardiography, electron microscopy, histopathologic analysis of cardiomyocyte fibrosis area, and Western blot analysis of matrix metalloproteinase-2 (MMP-2) and MMP-9 expression. Rats with DCM showed severe left ventricular dysfunction and cardiac fibrosis. Mangiferin mitigated DCM and prevented the accumulation of myocardial collagen. These anatomic findings were accompanied by significant improvements in cardiac function. Based on these results, we conclude that mangiferin has a therapeutic effect on DCM and improves cardiac function.

Gualou Xiebai Decoction prevents myocardial fibrosis by blocking TGF-beta/Smad signalling

OBJECTIVES

The present study is aimed to investigate the effect of Gualou Xiebai Decoction (GXD) ethanol extract on myocardial fibrosis and clarify the possible mechanism.

METHODS

Rats with ligated left anterior descending coronary artery were treated with GXD ethanol extract (1.14 g/kg, 2.27 g/kg, 4.53 g/kg) daily via gavage for 4 weeks. Histopathological changes and collagen distribution were evaluated by haematoxylin and eosin and Masson staining. The mRNA levels of Collagen I and Collagen III were detected by real-time PCR. The expressions of TGF-β1, TGFβ receptor (TGFβR)I, TGFβRII, P-Smad2/3 and Smad7 were determined by Western blot.

RESULTS

GXD treatment was significantly reduced the heart weight/body weight ratio (P < 0.05) as well as the left ventricle weight/body weight ratio (P < 0.05). It also significantly alleviated the degree of inflammation, decreased myocardial collagen volume fraction (P < 0.05 ∼ 0.01), together with markedly prevented the upregulations of Collagen I and Collagen III (P < 0.05 ∼ 0.01). Moreover, GXD downregulated expressions of TGF-β1, TGFβRI, TGFβRII, Smad2/3 whereas improved Smad7 expression in the myocardial fibrosis rats.

CONCLUSIONS

GXD ameliorates myocardial fibrosis induced by cardiac infarction with ligated left anterior descending coronary artery, the mechanism maybe involve in inhibiting the TGF-β1 signalling pathway.

P2Y1R-initiated, IP3R-dependent stimulation of astrocyte mitochondrial metabolism reduces and partially reverses ischemic neuronal damage in mouse

Glia-based neuroprotection strategies are emerging as promising new avenues to treat brain damage. We previously reported that activation of the glial-specific purinergic receptor, P2Y(1)R, reduces both astrocyte swelling and brain infarcts in a photothrombotic mouse model of stroke. These restorative effects were dependent on astrocyte mitochondrial metabolism. Here, we extend these findings and report that P2Y(1)R stimulation with the purinergic ligand 2-methylthioladenosine 5' diphosphate (2MeSADP) reduces and partially reverses neuronal damage induced by photothrombosis. In vivo neuronal morphology was confocally imaged in transgenic mice expressing yellow fluorescent protein under the control of the Thy1 promoter. Astrocyte mitochondrial membrane potentials, monitored with the potential sensitive dye tetra-methyl rhodamine methyl ester, were depolarized after photothrombosis and subsequently repolarized when P2Y(1)Rs were stimulated. Mice deficient in the astrocyte-specific type 2 inositol 1,4,5 trisphosphate (IP(3)) receptor exhibited aggravated ischemic dendritic damage after photothrombosis. Treatment of these mice with 2MeSADP did not invoke an intracellular Ca(2+) response, did not repolarize astrocyte mitochondria, and did not reduce or partially reverse neuronal lesions induced by photothrombotic stroke. These results demonstrate that IP(3)-Ca(2+) signaling in astrocytes is not only critical for P2Y(1)R-enhanced protection, but suggest that IP(3)-Ca(2+) signaling is also a key component of endogenous neuroprotection.

Phosphorylation of mammalian cytochrome c and cytochrome c oxidase in the regulation of cell destiny: respiration, apoptosis, and human disease

The mitochondrial oxidative phosphorylation (OxPhos) system not only generates the vast majority of cellular energy, but is also involved in the generation of reactive oxygen species (ROS), and apoptosis. Cytochrome c (Cytc) and cytochrome c oxidase (COX) represent the terminal step of the electron transport chain (ETC), the proposed rate-limiting reaction in mammals. Cytc and COX show unique regulatory features including allosteric regulation, isoform expression, and regulation through cell signaling pathways. This chapter focuses on the latter and discusses all mapped phosphorylation sites based on the crystal structures of COX and Cytc. Several signaling pathways have been identified that target COX including protein kinase A and C, receptor tyrosine kinase, and inflammatory signaling. In addition, four phosphorylation sites have been mapped on Cytc with potentially large implications due to its multiple functions including apoptosis, a pathway that is overactive in stressed cells but inactive in cancer. The role of COX and Cytc phosphorylation is reviewed in a human disease context, including cancer, inflammation, sepsis, asthma, and ischemia/reperfusion injury as seen in myocardial infarction and ischemic stroke.

Cardioprotective effect of mangiferin on left ventricular remodeling in rats

The purpose of this study was to clarify the protective role of mangiferin on postinfarction myocardial remodeling and potential mechanisms. The myocardial infarction (MI) model was established by ligating the left anterior descending coronary artery. Cardiac function, myocardial apoptosis and fibrosis, serum tumor necrosis factor-α (TNF-α) and phosphorylated p38 mitogen-activated protein kinase (MAPK) were examined by echocardiography, histological staining, ELISA and Western blot, respectively. Mangiferin attenuated MI and prevented the development of intercellular fibrosis. Western blotting underscores that the p38 MAPK cascade plays an important role in the cardioprotective effect of mangiferin during MI. Inhibition of p38 MAPK significantly decreased serum TNF-α levels. Transferase-mediated uridine nick end labeling and Masson staining also showed that mangiferin reduced apoptosis and fibrosis in myocardium remodeling. Based on these results, we conclude that mangiferin has a therapeutic effect on post-MI left ventricular remodeling and improves cardiac function.

Tribulosin suppresses apoptosis via PKC epsilon and ERK1/2 signaling pathway during hypoxia/reoxygenation in neonatal rat ventricular cardiac myocytes

Tribulosin (tigogenin 3-O-β-D-xylopyranosyl(1-2)-[β-D-xylopyranosyl (1-3)]-β-D-glucopyranosyl (1-4)-[a-L-rhamnopyranosyl(1-2)]-β-D-galactopyranoside), a component of gross saponins of Tribulus terrestris, has been shown to produce cytoprotective effects in heart. Yet, the precise mechanisms are not fully understood. We examined the mechanisms of tribulosin on myocardial protection. Ventricular myocytes were isolated from the heart of neonatal rats and were exposed to 3 h of hypoxia followed by 2 h reoxygenation. Apoptosis was induced by hypoxia/reoxygenation (H/R), and the expression of protein kinase C epsilon (PKCϵ) and extracellular signal-regulated kinase 1 and 2 (ERK1/2) in cultured neonatal rat cardiac myocytes was detected. The results indicated that treatment with tribulosin in the culture medium protected cardiac myocytes against apoptosis induced by H/R. PKCϵ and ERK1/2 expression increased after pretreated with tribulosin. In the presence of PKCϵ inhibitor co-treated with tribulosin, the expression of ERK1/2 was decreased in H/R cardiac myocytes. While preconditioned with PD98059, ERK1/2 inhibitor, no effects on the expression of PKCϵ were detected. Tribulosin has protective effects on cardiac myocytes against apoptosis induced by H/R injury via PKCϵ and ERK1/2 signaling pathway.