Effect of Atorvastatin Treatment on Isoproterenol-Induced Myocardial Infarction in Rats

Rat Model of Isoproterenol-Induced Myocardial Injury

Isoproterenol (ISO) administration produces significant biochemical and histological changes including oxidative stress, reactive oxygen species (ROS) overproduction, and inflammation that leads to aggravation of myocardial injury. Subcutaneous or intraperitoneal ISO injection into rats can replicate several features of human heart disease, making it a useful tool for comprehending the underlying mechanisms and evaluating potential therapeutic strategies. In the present chapter, we elaborate on how depending on the precise experimental goals and the intended level of severity, different dosages and regimens are employed to induce myocardial injury.

Gold nanoparticles synthesized from Euphorbia fischeriana root by green route method alleviates the isoprenaline hydrochloride induced myocardial infarction in rats

The procurance of gold nanoparticles in the plant extracts is an excellent way to attain nanomaterials natural and eco-friendly nanomaterials. The Dehydrated roots of Chinese Euphorbia fischeriana flowering plant are called "Lang-Du". In this study, the retrieving of gold nanoparticles from Euphorbia fischeriana root was amalgamated by standard procedure. Fabricated gold nanoparticles were portrayed through the investigations of ultraviolet and visible spectrophotometry (UV-Vis), Fourier transform infrared spectroscopy (FTIR), High resolution transmission electron microscopy (HRTEM) and X-ray diffraction (XRD). The UV-Vis and FTIR results explicated the obtained particles were sphere-shaped and the terpenoids of Euphorbia fischeriana had strong communications with gold surface. The HRTEM and XRD images exposed the produced gold nanoparticles had an extreme composition of crystal arrangement and excellent uniformed size of particles. In our study, the Isoprenaline induced myocardial damage established the elevation in TBARS, LOOH of heart tissues and notable decline in antioxidant enzymes SOD, CAT, GPx, and GSH. This biochemical result was additionally proved by histopathological assessment. Remarkably, the pretreatment with EF-AuNps(50 mg/kg b.w) illustrated stabilized levels of serum creatine and cardiotropins in myocardial infarcted animals. And further we understood the essential function of NF-ƙB, TNF-α, IL-6 signaling molecules and its way progression in the development of vascular tenderness.

Preclinical Toxicological Study of Release-Active Preparations for Prediction of Their Pharmacological Activity and Side Effects

We studied chronic toxicity of a few release-active preparations: Dietressa (release-active preparation of affinity-purified antibodies to type 1 cannabinoid receptor), Divasa (releaseactive preparation containing a combination of affinity-purified antibodies to brain-specific S-100 protein and endothelial NO-synthase), Cardostin (release-active preparation containing a combination of affinity-purified antibodies to C-terminal fragment of angiotensin II type 1 receptor and endothelial NO-synthase), and Bation (release-active preparation containing a combination of affinity-purified antibodies to IFN-γ and CD4). We evaluated not only side and toxic effects, but also the relationships between these effects and pharmacological activities of the preparations. The data of preclinical toxicological studies of the release-active preparations can be used for prediction of their pharmacological activity.

Most appropriate animal models to study the efficacy of statins: a systematic review

BACKGROUND

In animal models and clinical trials, statins are reported as effective in reducing cholesterol levels and lowering the risk of cardiovascular diseases. We have aggregated the findings in animal models - mice, rats and rabbits - using the technique of systematic review and meta-analysis to highlight differences in the efficacy of statins.

MATERIALS AND METHODS

We searched Medline and Embase. After examining all eligible articles, we extracted results about total cholesterol and other blood parameters, blood pressure, myocardial infarction and survival. Weighted and standard mean difference random effects meta-analysis was used to measure overall efficacy in prespecified species, strains and subgroups.

RESULTS

We included in systematic review 161 animal studies and we analysed 120 studies, accounting for 2432 animals. Statins lowered the total cholesterol across all species, although with large differences in the effect size: -30% in rabbits, -20% in mice and -10% in rats. The reduction was larger in animals fed on a high-cholesterol diet. Statins reduced infarct volume but did not consistently reduce the blood pressure or effect the overall survival. Few studies considered strains at high risk of cardiovascular diseases or hard outcomes.

CONCLUSIONS

Although statins showed substantial efficacy in animal models, few preclinical data considered conditions mimicking human pathologies for which the drugs are clinically indicated and utilized. The empirical finding that statins are more effective in lowering cholesterol derived from an external source (i.e. diet) conflicts with statin's supposed primary mechanism of action.

Exploration of pharmacological interventions to prevent isoproterenol-induced myocardial infarction in experimental models

High incidences of myocardial infarction associated with high morbidity and mortality, are a major concern and economic burden on industrialized nations. Persistent β-adrenergic receptor stimulation with isoproterenol leads to the development of oxidative stress, myocardial inflammation, thrombosis, platelet aggregation and calcium overload, which ultimately cause myocardial infarction. Therapeutic agents that are presently employed for the prevention and management of myocardial infarction are beta-blockers, antithrombotics, thrombolytics, statins, angiotensin converting enzyme inhibitors, angiotensin II type 1 receptor blockers, calcium channel blockers and nitrovasodilators. In spite of effective available interventions, the mortality rate of myocardial infarction is progressively increasing. Thus, there has been a regular need to develop effective therapies for the prevention and management of this insidious disease. In this review, the authors give an overview of the consequences of isoproterenol in the pathogenesis of cardiac disorders and various therapeutic possibilities to prevent these disorders.

Aqueous extract of Saussurea lappa root ameliorate oxidative myocardial injury induced by isoproterenol in rats

Saussurea lappa Clarke (Compositae), is commonly known as Kushta. In Ayurvedha, it is mentioned that the aqueous extract of the root S. lappa was used for treatment of angina pectoris. The present study was designed to investigate the cardioprotective effect of aqueous extract of root of S. lappa against isoproterenol induced myocardial injury. Myocardial injury in rat was induced by the administration of isoproterenol at a dose of 85 mg/kg, i.p., The rats were pretreated with the aqueous extract of S. lappa (AESL) in three different doses (100, 200 and 300 mg/kg, p.o.) through the oral route. Isoproterenol alone-treated rats showed increased serum concentration of lactate dehydrogenase (LDH), creatinine kinase (CK), and aspartate transaminase (AST), increased myocardial thiobarbituric acid reactive substances (TBARS) level, and decreased myocardial glutathione (GSH) level due to myocardial damage produced by isoproterenol. This is further conformed by histopathological changes. Chronic oral administration of AESL in three different doses significantly restored the level of myocardial LDH, CK, AST, TBARS, and GSH. The extract effect was compared with the reference standard α-tocopherol which also offered similar protection in biochemical and histopathological changes. The overall beneficial effect which was observed with the dose of 200 mg/kg indicated that AESL produced significant dose-dependent activity against isoproterenol induced myocardial injury.