Pharmacogenomic biomarkers in coronary artery disease: a narrative review.

Coronary artery disease (CAD) has a high mortality rate. Despite various therapeutic targets, non-responsiveness to drugs remains a prevalent issue. Pharmacogenomics assesses the way an individual's genetic attributes affect their likely response to drug therapy. Single-nucleotide polymorphisms play a crucial role in determining these outcomes. This review offers an overview of single-nucleotide polymorphisms investigated in clinical studies and their associations with drug response/nonresponse in the treatment of CAD. A total of 104 studies of whole sets of chromosomes and several genes were explored. A total of 161 polymorphisms exhibited associations with drug response/nonresponse in CAD across diverse ethnic populations. This pool can serve as a pharmacogenomic biomarker for predicting response to drug therapy in patients with CAD.

Hepatic drug metabolism and gut microbiome.

This chapter focuses on intestinal microbiota and its effect on drug metabolism. Here, we discussed about different drugs which are metabolized either by some enzymes or gut microbiota and their mechanism. Nowadays, consuming drugs without a doctor's prescription is common. This chapter will make people aware about its negative consequences and how it is related to gut microbiota dysbiosis. Intestinal disorders like inflammatory bowel disease (IBD), colorectal cancer (CRC) and metabolic disorders such as obesity and type 2 diabetes mellitus (T2D) are found to be affected with gut microbiota dysbiosis. To address this issue, we discussed a variety of strategies such as fecal microbiota transplantation (FMT), probiotics and antibiotic stewardship programs which are commonly used to tackle this problem.

Empagliflozin prohibits high-fructose diet-induced cardiac dysfunction in rats via attenuation of mitochondria-driven oxidative stress.

SGLT2 inhibitors show promising cardio-protection in the diabetic populace. However, the defending effect of SGLT2 inhibition in diabetes-associated cardiac complications and the molecular mechanism behind this effect are not thoroughly studied. Therefore, we aimed to investigate the effect of Empagliflozin, an SGLT2 inhibitor, in type-2 diabetic rat hearts. We induced type-2 diabetes in SD rats by giving a high-fructose diet for 20 weeks. We administered Empagliflozin (10 mg/kg p.o.) daily from the 12th week to the 20th week, along with high-fructose diet. We weighed the cardiac structure and function by echocardiography, electrocardiography, and blood pressure in diabetic rats. Other parameters like cardiac fibrosis, oxidative stress, and mitochondrial dynamics by protein expression were measured. To simulate a similar in-vivo condition, we persuaded insulin resistance in H9c2 cells by palmitic acid (PA) treatment. We then examined glucose uptake, cellular ROS, mitochondrial ROS and membrane potential in the presence and absence of Empagliflozin treatment. We saw a significant perturbation of the majority of the parameters associated with cardiac structure and function in high-fructose diet-induced diabetic rats. We found that administration of Empagliflozin improved all the perturbed parameters by attenuating insulin resistance, oxidative stress, and cardiac fibrosis and also by promoting cardiac mitochondrial fusion in high-fructose diet-induced type-2 diabetic rats. Empagliflozin also reduced palmitate-induced insulin resistance, total cellular ROS, and mitochondrial ROS in H9c2 cells. Our study concluded that SGLT2 inhibition with Empagliflozin prevented the high-fructose diet-insulted cardiac function by suppressing insulin resistance and oxidative stress and promoting mitochondrial fusion.

Sirt1 and Sirt3 Activation Improved Cardiac Function of Diabetic Rats via Modulation of Mitochondrial Function.

In the present study, we aimed to evaluate the effect of Sirt1, Sirt3 and combined activation in high fructose diet-induced insulin resistance rat heart and assessed the cardiac function focusing on mitochondrial health and function. We administered the Sirt1 activator; SRT1720 (5 mg/kg, i.p.), Sirt3 activator; Oroxylin-A (10 mg/kg i.p.) and the combination; SRT1720 + Oroxylin-A (5 mg/kg and 10 mg/kg i.p.) daily from 12th week to 20th weeks of study. We observed significant perturbations of most of the cardiac structural and functional parameters in high fructose diet-fed animals. Administration of SRT1720 and Oroxylin-A improved perturbed cardiac structural and functional parameters by decreasing insulin resistance, oxidative stress, and improving mitochondrial function by enhancing mitochondrial biogenesis, OXPHOS expression and activity in high fructose diet-induced insulin-resistant rats. However, we could not observe the synergistic effect of SRT1720 and Oroxylin-A combination. Similar to in-vivo study, perturbed mitochondrial function and oxidative stress observed in insulin-resistant H9c2 cells were improved after activation of Sirt1 and Sirt3. We observed that Sirt1 activation enhances Sirt3 expression and mitochondrial biogenesis, and the opposite effects were observed after Sirt1 inhibition in cardiomyoblast cells. Taken together our results conclude that activation of Sirt1 alone could be a potential therapeutic target for diabetes-associated cardiovascular complications.

Chloroquine and Hydroxychloroquine for the Treatment of COVID-19: a Systematic Review and Meta-analysis.

BACKGROUND: There is no effective therapy for COVID-19. Hydroxychloroquine (HCQ) and chloroquine (CQ) have been used for its treatment but their safety and efficacy remain uncertain. OBJECTIVE: We performed a systematic review to synthesize the available data on the efficacy and safety of CQ and HCQ for the treatment of COVID-19. METHODS: Two reviewers searched for published and pre-published relevant articles between December 2019 and 8 June 2020. The data from the selected studies were abstracted and analyzed for efficacy and safety outcomes. Critical appraisal of the evidence was done by Cochrane risk of bias tool and Newcastle Ottawa Scale. The quality of evidence was graded as per the GRADE approach. RESULTS: We reviewed 12 observational and 3 randomized trials which included 10,659 patients of whom 5713 received CQ/HCQ and 4966 received only standard of care. The efficacy of CQ/HCQ for COVID-19 was inconsistent across the studies. Meta-analysis of included studies revealed no significant reduction in mortality with HCQ use [RR 0.98 95% CI 0.66-1.46], time to fever resolution (mean difference - 0.54 days (- 1.19-011)) or clinical deterioration/development of ARDS with HCQ [RR 0.90 95% CI 0.47-1.71]. There was a higher risk of ECG abnormalities/arrhythmia with HCQ/CQ [RR 1.46 95% CI 1.04 to 2.06]. The quality of evidence was graded as very low for these outcomes. AUTHORS' CONCLUSION: The available evidence suggests that CQ or HCQ does not improve clinical outcomes in COVID-19. Well-designed randomized trials are required for assessing the efficacy and safety of HCQ and CQ for COVID-19.

Vitamin D Deficiency in Rats Causes Cardiac Dysfunction by Inducing Myocardial Insulin Resistance.

SCOPE: Cause-effect relationship between vitamin D deficiency and cardiometabolic abnormalities remains undefined. The aim is to investigate the role of vitamin D deficiency in cardiac failure, through possible involvement in myocardial insulin signaling. METHODS AND RESULTS: Male SD rats (n = 6) are fed a normal diet (Con), vitamin D-deficient diet [Con(-)], or high-fat, high fructose diet (HFHFrD) for 20 weeks. Cardiac hypertrophy and fetal gene program are confirmed in Con(-) group. Cardiac dysfunction is assessed by echocardiography. Elevated renin, TGF-ß and collagen-1α mRNAs, p-ERK1/2, and perivascular fibrosis indicate cardiac remodeling in Con(-) group. Increased serum insulin, triglycerides, and blood pressure, and decreased glucose tolerance and HDL cholesterol are observed in Con(-) rats. Decreased p-Akt/Akt, GLUT4, SOD2, and catalase, and increased NF-κB, TNF-α, and IL-6 are observed in Con(-) hearts. In H9c2 cells, calcitriol attenuates palmitate-induced insulin resistance. VDR-silenced H9c2 cells show reduced Akt phosphorylation, GLUT4 translocation, and 2-NBDG uptake. Findings in Con(-) and HFHFrD groups are comparable. CONCLUSION: Vitamin D deficiency in rats mimic high-fat-, high-fructose-induced metabolic syndrome and cardiac dysfunction. This study demonstrates that vitamin D deficiency is an independent risk factor for heart failure, at least in part, through induction of myocardial insulin resistance.

Beneficial effects of fenofibrate in pulmonary hypertension in rats.

Pulmonary hypertension (PH) is a morbid complication of cardiopulmonary as well as several systemic diseases in humans. It is rapidly progressive and fatal if left untreated. In the present study, we investigated the effect of PPARα agonist fenofibrate (FF) on monocrotaline (MCT)-induced PH in rats. FF, because of its pleiotropic property, could be helpful in reducing inflammation, oxidative stress, and reactive oxygen species. On day 1, MCT (50 mg/kg, s.c.) was given to all the rats in MCT, sildenafil, and FF group except normal control rats. After 3 days of giving MCT, sildenafil (175 µg/kg, orally) and FF (120 mg/kg, orally) were given for 25 days. Echocardiography, hemodynamic parameters, fulton's index, histopathology, oxidative stress parameters, inflammatory markers, Bcl2/Bax gene expression ratio in the right ventricle, and protein expression for NOX-1 in lungs were studied in all the groups. FF has shown to prevent decrease in ratio of pulmonary artery acceleration time to ejection time, increase in ratio of right ventricular outflow tract dimension to aortic outflow dimension, rise in right ventricular systolic pressure, right ventricular hypertrophy, increase in the percentage medial wall thickness (%MWT), increase in oxidative stress and inflammation, increase in NADPH oxidase-1 (NOX-1) expression, and decrease in mRNA expression of Bcl2/Bax ratio caused by MCT. To conclude, FF prevented MCT-induced PH in rats by various mechanisms. It might be helpful in preventing PH in patients who are likely to develop PH.

Beneficial Effect of Ocimum sanctum (Linn) against Monocrotaline-Induced Pulmonary Hypertension in Rats.

BACKGROUND: The study was designed to explore any beneficial effect of Ocimum sanctum (Linn) (OS) in experimental pulmonary hypertension (PH) in rats. OS is commonly known as “holy basil” and “Tulsi” and is used in the Indian System of Medicine as antidiabetic, antioxidant, hepatoprotective, adaptogenic, and cardioprotective. METHODS: Monocrotaline (MCT) administration caused development of PH in rats after 28 days and rats were observed for 42 days. Treatments (sildenafil; 175 µg/kg, OS; 200 mg/kg) were started from day 29 after the development of PH and continued for 14 days. Parameters to assess the disease development and effectiveness of interventions were echocardiography, right and left ventricular systolic pressures, and right ventricular end diastolic pressure, percentage medial wall thickness (%MWT) of pulmonary artery, oxidative stress markers in lung tissue, NADPH oxidase (Nox-1) protein expression in lung, and mRNA expression of Bcl2 and Bax in right ventricular tissue. RESULTS: OS (200 mg/kg) treatment ameliorated increased lung weight to body weight ratio, right ventricular hypertrophy, increased RVSP, and RVoTD/AoD ratio. Moreover, OS treatment decreases Nox-1 expression and increases expression of Bcl2/Bax ratio caused by MCT. CONCLUSION: The present study demonstrates that OS has therapeutic ability against MCT-induced PH in rat which are attributed to its antioxidant effect. The effect of OS was comparable with sildenafil.

Herb-Drug Interactions in Neurological Disorders: A Critical Appraisal.

BACKGROUND: Herbal drugs are being used worldwide in a variety of debilitating neurological and psychiatric disorders such as cerebrovascular accident, Alzheimer's disease, Parkinson's disease and schizophrenia. However, unlike drugs of modern medicine, herbal drugs are complex products containing multiple pharmacologically active constituents. The nature and relative amounts of these constituents vary due to diverse factors such as but not limited to source of the plant(s), local environmental conditions, parts of the plant used, storage, method of extract preparation, accidental contamination or intentional adulteration. Further, they are handled by the human body like modern drugs and subjected to the processes of absorption, distribution, metabolism and excretion. In each of these processes, they can potentially interact with modern drugs due to sharing of similar transport proteins, metabolizing cytochrome P450 (CYP450) enzymes and uptake / efflux pumps. Moreover, herbal drugs can also inhibit or induce CYP450 enzymes or inactivate transporters leading to Herb-Drug interactions (HDIs). METHOD: In this narrative review, we have analyzed the clinically reported as well as potential HDIs between 10 common herbal drugs viz. Ginkgo, Ginseng, St. John's Wort, Grapefruit, Black and Long Pepper, Curcumin, Brahmi, Kava, Garlic and Valerian and modern medicines used in neurological and psychiatric disorders with their proven or postulated underlying mechanism(s). RESULTS: Though a number of potential pharmacokinetic and/or pharmacodynamic HDIs have been examined, clinically significant alteration of response to modern medicines and/or serious adverse effects are apparently scarce except for Grapefruit and St. John's Wort. CONCLUSION: Physicians and patients should exercise caution when using herbal drugs and modern medicines concomitantly so that the recognized serious HDIs can be avoided.

α-Amyrin attenuates high fructose diet-induced metabolic syndrome in rats.

This study investigated the effect of α-amyrin (a pentacyclic triterpene) on high-fructose diet (HFD)-induced metabolic syndrome in rats. Male Wistar rats were randomly distributed into different groups. The control group was fed normal rat chow diet. The HFD group was fed HFD (60%; w/w) for 42 days. Pioglitazone (10 mg/kg, orally, once daily) was used as a standard drug. α-Amyrin was administered in 3 doses (50, 100, and 200 mg/kg, orally, once daily along with HFD). Plasma glucose, total cholesterol, triglycerides, and high-density lipoprotein cholesterol (HDL-C) were estimated. Changes in blood pressure, oral glucose tolerance, and insulin tolerance were measured. Hepatic oxidative stress as well as messenger RNA (mRNA) and protein levels of peroxisome proliferator-activated receptor alpha (PPAR-α) were analyzed. A significant increase in systolic blood pressure, plasma glucose, total cholesterol, and plasma triglycerides and a significant decrease in HDL-C were observed in HFD rats as compared with control rats. Glucose tolerance and insulin tolerance were also significantly impaired with HFD. α-Amyrin prevented these changes in a dose-dependent manner. Hepatic oxidative stress as well as micro- and macrovesicular fatty changes in hepatocytes caused by HFD were also attenuated by α-amyrin. α-Amyrin preserved the hepatic mRNA and protein levels of PPAR-α, which was reduced in HFD group. This study thus demonstrates that α-amyrin attenuates HFD-induced metabolic syndrome in rats.

Beneficial effects of aqueous extract of stem bark of Terminalia arjuna (Roxb.), An ayurvedic drug in experimental pulmonary hypertension.

ETHNOPHARMACOLOGICAL RELEVANCE: The stem bark of Terminalia arjuna (Roxb.) is widely used in Ayurveda in various cardiovascular diseases. Many animal and clinical studies have validated its anti-ischemic, antihypertensive, antihypertrophic and antioxidant effects. Pulmonary hypertension (PH) is a fatal disease which causes right ventricular hypertrophy and right heart failure. Pulmonary vascular smooth muscle hypertrophy and increased oxidative stress are major pathological features of PH. As available limited therapeutic options fail to reduce the mortality associated with PH, alternative areas of therapy are worth exploring for potential drugs, which might be beneficial in PH. AIM OF THE STUDY: The effect of a standardised aqueous extract of the stem bark of Terminalia arjuna (Roxb.) in preventing monocrotaline (MCT)-induced PH in rat was investigated. MATERIALS AND METHODS: The study was approved by Institutional Animal Ethics Committe. Male Wistar rats (150-200g) were randomly distributed into five groups; Control, MCT (50mg/kg subcutaneously once), sildenafil (175µg/kg/day three days after MCT for 25 days), and Arjuna extract (TA125 and TA250 mg/kg/day orally after MCT for 25 days). PH was confirmed by right ventricular weight to left ventricular plus septum weight (Fulton index), right ventricular systolic pressure (RVSP), echocardiography, percentage medial wall thickness of pulmonary arteries (%MWT). Oxidative stress in lung was assessed by super oxide dismutase (SOD), catalase, reduced glutathione (GSH) and thiobarbituric acid reactive substance (TBARS). The protein expressions of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (NOX-1) in lung and gene expression of Bcl2 and Bax in heart were analyzed by Western blot and RT PCR respectively. RESULTS: MCT caused right ventricular hypertrophy (0.58±0.05 vs 0.31±0.05; P<0.001 vs. control) and increase in RVSP (33.5±1.5 vs 22.3±4.7mm of Hg; P<0.001). Both sildenafil and Arjuna prevented hypertrophy and RVSP. Pulmonary artery acceleration time to ejection time ratio in echocardiography was decreased in PH rats (0.49±0.05 vs 0.32±0.06; P<0.001) which was prevented by sildenafil (0.44±0.06; P<0.01) and TA250 (0.45±0.06; P<0.01). % MWT of pulmonary arteries was increased in PH and was prevented by TA250. Increase in TBARS (132.7±18.4 vs 18.8±1.6nmol/mg protein; P<0.001) and decrease in SOD (58.4±14.1 vs 117.4±26.9U/mg protein; P<0.001) and catalase (0.30±0.05 vs 0.75±0.31U/mg protein; P<0.001) were observed in lung tissue of PH rats, which were prevented by sildenafil and both the doses of Arjuna extract. Protein expression of NOX1 was significantly increased in lung and gene expression of Bcl2/Bax ratio was significantly decreased in right ventricle in MCT-induced PH, both were significantly prevented by Arjuna and sildenafil. CONCLUSIONS: Aqueous extract of Terminalia arjuna prevented MCT-induced pulmonary hypertension which may be attributed to its antioxidant as well as its effects on pulmonary arteriolar wall thickening.

Effect of Atorvastatin and Pioglitazone on Plasma Levels of Adhesion Molecules in Non-Diabetic Patients With Hypertension or Stable Angina or Both.

BACKGROUND: It was to study the effect of atorvastatin, pioglitazone and their combination on plasma levels of adhesion molecules in patients with hypertension or stable angina or both. METHODS: It was an open-label, randomized parallel-group study. Forty-five atorvastatin-naive patients with hypertension or stable angina or both, were randomized to receive either atorvastatin (19 patients; 10 mg OD for 12 weeks) or pioglitazone (26 patients; 30 mg OD for 12 weeks). Another group of 30 patients who were already on atorvastatin were put on add-on pioglitazone therapy (pioglitazone (15 mg OD) + atorvastatin (10 mg OD) for 12 weeks). Plasma high-sensitivity C-reactive protein (hsCRP), soluble intercellular adhesion molecule-1 (sICAM-1) and soluble vascular cell adhesion molecule-1 (sVCAM-1) levels were measured at baseline and after 12 weeks of therapy. RESULTS: Atorvastatin monotherapy significantly reduced plasma sICAM-1, but pioglitazone monotherapy did not produce any significant effect. Addition of pioglitazone in patients already receiving atorvastatin also significantly reduced plasma sICAM-1 level. However, there was no significant change in plasma hsCRP and sVCAM-1 levels in any of the groups after 12 weeks of therapy. CONCLUSION: There is therapeutic advantage of combining pioglitazone and atorvastatin on plasma sICAM-1 levels.

The effect of thymoquinone, an active component of Nigella sativa, on isoproterenol induced myocardial injury.

Myocardial injury constitutes a major cause of morbidity and mortality in humans. Present study aimed to investigate protective role of thymoquinone, which is an active principle of Nigella sativa (N. sativa) seed (Commonly called as black seed), in isoproterenol induced myocardial injury, a classical example of excess catecholamines related coronary insufficiency and stress cardiomyopathy. Thymoquinone, in olive oil, was administered orally (12.5, 25 and 50mg/kg) to three groups of Wistar albino rats for 7 days, while two control groups were given plain olive oil. Thereafter, thymoquinone receiving groups and one control group were injected, subcutaneously, with isoproterenol (125mg/kg) for 2 days. Myocardial injury was assessed by biochemical markers (plasma LDH, TBARS, GR & SOD and myocardial GSH/GSSG ratio) and cardiac histopathology. Plasma LDH, TBARS and GR increased in control groups receiving isoproterenol, while there was a dose related decrease in these markers in thymoquinone treated groups, down to levels in controls given olive oil only. Decrease in plasma SOD and myocardial GSH/GSSG ratio and histological changes produced with isoproternol were also reversed in thymoquinone treated rats. Results of our study revealed that thymoquinone protects the heart from injury induced by isoproterenol.

Genistein prevents isoproterenol-induced cardiac hypertrophy in rats.

Genistein, an isoflavone and a rich constituent of soy, possesses important regulatory effects on nitric oxide (NO) synthesis and oxidative stress. Transient and low release of NO by endothelial nitric oxide synthase (eNOS) has been shown to be beneficial, while high and sustained release by inducible nitric oxide synthase (iNOS) may be detrimental in pathological cardiac hypertrophy. The present study was designed to evaluate whether genistein could prevent isoproterenol-induced cardiac hypertrophy in male Wistar rats (150-200 g, 10-12 weeks old) rats. Isoproterenol (5 mg·(kg body weight)(-1)) was injected subcutaneously once daily for 14 days to induced cardiac hypertrophy. Genistein (0.1 and 0.2 mg·kg(-1), subcutaneous injection once daily) was administered along with isoproterenol. Heart tissue was studied for myocyte size and fibrosis. Myocardial thiobarbituric acid reactive substances (TBARS), glutathione (GSH), superoxide dismutase (SOD), catalase levels, and 1-OH proline (collagen content) were also estimated. Genistein significantly prevented any isoproterenol-induced increase in heart weight to body weight ratio, left ventricular mass (echocardiographic), myocardial 1-OH proline, fibrosis, myocyte size and myocardial oxidative stress. These beneficial effects of genistein were blocked by a nonselective NOS inhibitor (L-NAME), but not by a selective iNOS inhibitor (aminoguanidine). Thus, the present study suggests that the salutary effects of genistein on isoproterenol-induced cardiac hypertrophy may be mediated through inhibition of iNOS and potentiation of eNOS activities.

Oxidative stress and cardiac hypertrophy: a review.

Cardiac hypertrophy (CH) is an adaptive response of the heart to pressure overload. It is a common pathological feature in the natural course of some major cardiovascular diseases, like, hypertension and myocardial infarction. Cardiac hypertrophy is strongly associated with an increased risk of heart failure and sudden cardiac death. The complex and dynamic pathophysiological mechanisms of CH has been the focus of intense scientific investigation, in an effort to design preventive and curative strategies. Oxidative stress has been identified as one of the key contributing factors in the development of cardiac hypertrophy. In this review, evidences supporting the oxidative stress as a cause of cardiac hypertrophy with emphasis on mitochondrial oxidative stress and possible options for pharmacological interventions have been discussed. Reactive oxygen species (ROS) also activate a broad variety of hypertrophy signaling kinases and transcription factors, like, MAP kinase, NF K-B, etc. In addition to profound alteration of cellular function, ROS modulate the extracellular matrix function, evidenced by increased interstitial and perivascular fibrosis. Translocator protein (TSPO) present in the outer mitochondrial membrane is known to be involved in oxidative stress and cardiovascular pathology. Recently, its role in cardiac hypertrophy has been reported by us. All these evidences strongly provide support to beneficial role of drugs which selectively interfere with the generation of free radicals or augment endogenous antioxidants in cardiac hypertrophy.

PLGA nanoparticles for peptide receptor radionuclide therapy of neuroendocrine tumors: a novel approach towards reduction of renal radiation dose.

BACKGROUND: Peptide receptor radionuclide therapy (PRRT), employed for treatment of neuroendocrine tumors (NETs) is based on over-expression of Somatostatin Receptors (SSTRs) on NETs. It is, however, limited by high uptake and retention of radiolabeled peptide in kidneys resulting in unnecessary radiation exposure thus causing nephrotoxicity. Employing a nanocarrier to deliver PRRT drugs specifically to the tumor can reduce the associated nephrotoxicity. Based on this, (177)Lu-DOTATATE loaded PLGA nanoparticles (NPs) were formulated in the present study, as a potential therapeutic model for NETs. METHODOLOGY AND FINDINGS: DOTATATE was labeled with Lutetium-177 ((177)Lu) (labeling efficiency 98%; R(f)∼0.8). Polyethylene Glycol (PEG) coated (177)Lu-DOTATATE-PLGA NPs (50:50 and 75:25) formulated, were spherical with mean size of 304.5±80.8 and 733.4±101.3 nm (uncoated) and 303.8±67.2 and 494.3±71.8 nm (coated) for PLGA(50:50) and PLGA(75:25) respectively. Encapsulation efficiency (EE) and In-vitro release kinetics for uncoated and coated NPs of PLGA (50:50 & 75:25) were assessed and compared. Mean EE was 77.375±4.98% & 67.885±5.12% (uncoated) and 65.385±5.67% & 58.495±5.35% (coated). NPs showed initial burst release between 16.64-21.65% with total 42.83-44.79% over 21 days. The release increased with coating to 20.4-23.95% initially and 60.97-69.12% over 21 days. In-vivo studies were done in rats injected with (177)Lu-DOTATATE and (177)Lu-DOTATATE-NP (uncoated and PEG-coated) by imaging and organ counting after sacrificing rats at different time points over 24 hr post-injection. With (177)Lu-DOTATATE, renal uptake of 37.89±10.2%ID/g was observed, which reduced to 4.6±1.97% and 5.27±1.66%ID/g with uncoated and coated (177)Lu-DOTATATE-NP. The high liver uptake with uncoated (177)Lu-DOTATATE-NP (13.68±3.08% ID/g), reduced to 7.20±2.04%ID/g (p = 0.02) with PEG coating. CONCLUSION: PLGA NPs were easily formulated and modified for desired release properties. PLGA 50:50 NPs were a more suitable delivery vehicle for (177)Lu-DOTATATE than PLGA 75:25 because of higher EE and slower release rate. Reduced renal retention of (177)Lu-DOTATATE and reduced opsonisation strongly advocate the potential of (177)Lu-DOTATATE-PLGA-PEG NPs to reduce radiation dose in PRRT.

Effect of U50,488H, a κ-opioid receptor agonist on myocardial α-and ß-myosin heavy chain expression and oxidative stress associated with isoproterenol-induced cardiac hypertrophy in rat.

Both oxidative stress and ß-MHC expression are associated with pathological cardiac hypertrophy. ß-adrenergic receptor stimulation plays an important role in cardiac hypertrophy. Recent studies have reported a negative interplay between opioid receptors and adrenoceptors in heart. This study investigated the effect of U50,488H (a selective κ-opioid receptor agonist) on myocardial oxidative stress and α- and ß-MHC expression in isoproterenol-induced cardiac hypertrophy. Male Wistar rats were administered normal saline (control), isoproterenol (ISO) (5 mg/kg BW s.c. OD), and isoproterenol with U50,488H (0.4 and 0.6 mg/kg BW, i.p. OD) for 14 days. In a separate group, nor-binaltorphimine (nor-BNI) (0.5 mg/kg, BW, i.p.) (κ-receptor antagonist) was administered along with ISO and U50,488H. ISO administration caused significant increase in left ventricular (LV) wall thicknesses, LV mass in echocardiography, heart weight to body weight ratio, and myocyte size as compared to control. Both the doses of U50,488H offered significant protection against these changes. The higher dose of U50,488H significantly prevented ISO-induced increase in myocardial lipid peroxidation and depletion of myocardial antioxidants (glutathione, superoxide dismutase, and catalase), while a similar trend (although not significant) was observed with the lower dose also. ISO-induced myocardial fibrosis was also significantly attenuated by both the doses of U50,488H. Isoproterenol-induced ß-MHC expression in the hypertrophied heart was not altered by either doses of U50,488H, however, the latter prevented the loss of myocardial α-MHC expression. All these effects of U50,488H were blocked by nor-BNI. This study provides the evidence that U50,488H reduced oxidative stress and preserved expression of α-MHC in isoproterenol-induced cardiac hypertrophy.

Peripheral benzodiazepine receptor ligand Ro5-4864 inhibits isoprenaline-induced cardiac hypertrophy in rats.

Oxidative stress plays a significant role in the pathogenesis of cardiac hypertrophy. Peripheral benzodiazepine receptors are ubiquitously expressed in various tissues, including the heart. Peripheral benzodiazepine receptors have been reported to be involved in the protection of cells against oxygen radical damage. The present study was designed to determine whether Ro5-4864 (a peripheral benzodiazepine receptor ligand) can inhibit isoprenaline-induced cardiac hypertrophy. Male Wistar rats (body weight 150-200g) were administered, isoprenaline (5mg/kg, body weight, subcutaneously) alone or along with Ro5-4864 (0.1 and 0.5mg/kg, body weight, intraperitoneally) once daily for 14days. Control rats received normal saline subcutaneously (1.0ml/kg). Isoprenaline-induced changes in heart weight to body weight ratio, left ventricular wall thickness (M-mode echocardiography and gross morphometry) and myocyte size were significantly prevented by both the doses of Ro5-4864. Ro5-4864 also attenuated isoprenaline-induced increase in interstitial fibrosis, lipid peroxidation and changes in endogenous antioxidants (glutathione, superoxide dismutase and catalase). Isoprenaline-induced cardiac hypertrophy was associated with increased expression of beta myosin heavy chain, which was also prevented by Ro5-4864. This is the first study to demonstrate a salutary effect of Ro5-4864 in experimental cardiac hypertrophy.

Catecholamine-induced myocardial fibrosis and oxidative stress is attenuated by Terminalia arjuna (Roxb.).

OBJECTIVES: Myocardial fibrosis and oxidative stress accompany a number of cardiac disorders such as hypertrophic cardiomyopathy, hypertensive heart disease and cardiac failure. Stem bark of Terminalia arjuna has been advocated for cardiac ailments. The present study evaluated the effects of T. arjuna bark extract on myocardial fibrosis and oxidative stress induced by chronic beta-adrenoceptor stimulation. METHODS: Aqueous extract of T. arjuna bark was evaluated at 63, 125 and 250 mg/kg given orally for antifibrotic and antioxidant effects in rats given the selective beta-adrenoceptor agonist isoprenaline (5 mg/kg s.c.) for 28 days. Captopril (50 mg/kg per day, given orally), an inhibitor of angiotensin-converting enzyme used as a standard cardioprotective drug, was used as a positive control. KEY FINDINGS: Isoprenaline caused fibrosis, increased oxidative stress and cardiac hypertrophy (increased heart weight : body weight ratio and cardiomyocyte diameter). The T. arjuna bark extract and captopril significantly prevented the isoprenaline-induced increase in oxidative stress and decline in endogenous antioxidant level. Both also prevented fibrosis but not the increase in heart weight : body weight ratio. CONCLUSIONS: T. arjuna protects against myocardial changes induced by chronic beta-adrenoceptor stimulation.

A randomized controlled trial of antioxidant supplementation for pain relief in patients with chronic pancreatitis.

BACKGROUND & AIMS: Oxidative stress has been implicated in the pathophysiology of chronic pancreatitis (CP). We evaluated the effects of antioxidant supplementation on pain relief, oxidative stress, and antioxidant status in patients with CP. METHODS: In a placebo-controlled double blind trial, consecutive patients with CP were randomized to groups that were given placebo or antioxidants for 6 months. The primary outcome measure was pain relief, and secondary outcome measures were analgesic requirements, hospitalization, and markers of oxidative stress (thiobarbituric acid-reactive substances [TBARS]) and antioxidant status (ferric-reducing ability of plasma [FRAP]). RESULTS: Patients (age 30.5+/-10.5 years, 86 male, 35 alcoholic, and 92 with idiopathic CP) were assigned to the placebo (n=56) or antioxidant groups (n=71). After 6 months, the reduction in the number of painful days per month was significantly higher in the antioxidant group compared with the placebo group (7.4+/-6.8 vs 3.2+/-4, respectively; P< .001; 95% CI, 2.07, 6.23). The reduction in the number of analgesic tablets per month was also higher in the antioxidant group (10.5+/-11.8 vs 4.4+/-5.8 respectively; P= .001; 95% CI, 2.65, 9.65). Furthermore, 32% and 13% of patients became pain free in the antioxidant and placebo groups, respectively (P= .009). The reduction in the level of TBARS and increase in FRAP were significantly higher in the antioxidant group compared with the placebo group (TBARS: placebo 1.2+/-2.7 vs antioxidant 3.5+/-3.4 nmol/mL; P= .001; 95% CI 0.96, 3.55; FRAP: placebo -5.6+/-154.9 vs antioxidant 97.8+/-134.9 microMFe(+2) liberated, P= .001, 95% CI 44.98, 161.7). CONCLUSIONS: Antioxidant supplementation was effective in relieving pain and reducing levels of oxidative stress in patients with CP.