Type 2 diabetes-induced cardiovascular complications: comparative evaluation of spironolactone, atenolol, metoprolol, ramipril and perindopril

Syringic Acid Ameliorates Cardiac, Hepatic, Renal and Neuronal Damage Induced by Chronic Hyperglycaemia in Wistar Rats: A Behavioural, Biochemical and Histological Analysis

This study investigated the effects of syringic acid (SA) on renal, cardiac, hepatic, and neuronal diabetic complications in streptozotocin-induced neonatal (nSTZ) diabetic rats. STZ (110 mg/kg i.p) was injected into Wistar rat neonates as a split dose (second and third postnatal day). Diabetes mellitus was diagnosed in adults by measuring fasting blood glucose levels, urine volume, and food and water intake. The treatment of SA (25 mg/kg, 50 mg/kg p.o) was given from the 8th to 18th postnatal week. To assess the development of diabetic complications and the effect of therapy, biochemical indicators in serum and behavioural parameters were recorded at specific intervals during the study period. SA (25 mg/kg, 50 mg/kg p.o) treatment reduced hyperglycaemia, polydipsia, polyphagia, polyuria, relative organ weight, cardiac hypertrophic indices, inflammatory markers, cell injury markers, glycated haemoglobin, histopathological score, and oxidative stress, and increased Na/K ATPase activity. These findings suggest that SA might significantly alleviate diabetic complications and/or renal, neuronal, cardiac, and hepatic damage in nSTZ diabetic rats.

Evaluation of selected antidiabetics in cardiovascular complications associated with cancer cachexia

So far, the cardio-protective potential of antidiabetics is proved, but their effect on cardiovascular complications associated with cancer cachexia is not explored until now. Insulin resistance and glucose intolerance along with systemic inflammation are prominent in cachexia but the potential effect of antidiabetic agents especially those belonging to biguanide, DPP4 inhibitors and SGLT2 on the heart are not studied till now. In present study, the effect of metformin, vildagliptin, teneligliptin, dapagliflozin and empagliflozin on cardiovascular complications associated with cancer cachexia by using B16F1 induced metastatic cancer cachexia and urethane-induced cancer cachexia was studied. These antidiabetic agents proved to be beneficial against cachexia-induced atrophy of the heart, preserved ventricular weights, maintained cardiac hypertrophic index, preserved the wasting of cardiac muscles assessed by HE staining, Masson trichrome staining, periodic acid Schiff staining and picro-Sirius red staining. Altered cardiac gene expression was attenuated after treatment with selected antidiabetics, thus preventing cardiac atrophy. Also, antidiabetic agents treatment improved the serum creatinine kinase MB, Sodium potassium ATPase and collagen in the heart. Reduction in blood pressure and heart rate was observed after treatment with antidiabetic agents. Results of our study show that the selected antidiabetics prove to be beneficial in attenuating the cardiac atrophy and helps in regulation of hemodynamic stauts in cancer cachexia-induced cardiovascular complications. Our study provides some direction towards use of selected antidiabetic agents in the management of cardiovascular complications associated with cancer cachexia and the study outcomes can be useful in desiging clinical trials.

Systemic study of selected histone deacetylase inhibitors in cardiac complications associated with cancer cachexia

Cancer cachexia is mainly characterized by wasting of skeletal muscles and fat and body weight loss, along with severe complications of major organs like liver, heart, brain and bone. There can be diminishing performance of these major organs as cancer cachexia progresses, one such drastic effect on the cardiac system. In the present study, differential effect of histone deacetylase inhibitors (HDACi) on cardiac complications associated with cancer cachexia is studied. Two models were used to induce cancer cachexia: B16F1 induced metastatic cancer cachexia and Lewis lung carcinoma cell - induced cancer cachexia. Potential of Class I HDACi entinostat, Class II HDACi MC1568, and nonspecific HDACi sodium butyrate on cardiac complications were evaluated using the cardiac hypertrophy markers, hemodynamic markers, and cardiac markers along with histopathological evaluation of heart sections by Periodic acid-Schiff staining, Masson's trichrome staining, Picro-sirius red staining, and haematoxylin and eosin staining. Immunohistochemistry evaluation by vimentin and caspase 3 protein expression was evaluated. Entinostat showed promising results by attenuating the cardiac complications, and MC1568 treatment further exacerbated the cardiac complications, while non-conclusive effect were recorded after treatment with sodium butyrate. This study will be helpful in evaluating other HDACi for potential in cardiac complications associated with cancer cachexia.

Cardiac Complications: The Understudied Aspect of Cancer Cachexia

The global burden of cancer cachexia is increasing along with drastic increase in cancer patients. Cancer itself leads to cachexia, and cachexia development is associated with events like altered hemodynamics, and reduced functional capacity of the heart among others which lead to failure of the heart and are called cardiovascular complications associated with cancer cachexia. In some patients, the anti-cancer therapy also leads to this cardiovascular complications. So, in this review, an attempt is made to understand the mechanisms, pathophysiology of cardiovascular events in cachectic patients. Important processes which cause cardiovascular complications include alterations in the structure of the heart, loss of cardiac mass and functioning, cardiac fibrosis and cardiac remodeling, apoptosis, cardiac muscle atrophy, and mitochondrial alterations. Previously, the available treatment options were limited to nutraceuticals and physical exercise. Recently, studies with some prospective agents that can improve cardiac health have been reported, but whether their action is effective in cardiovascular complications associated with cancer cachexia is not known or are under trial.

NRF2 in Cardiovascular Diseases: a Ray of Hope!

Heart failure is a worldwide pandemic influencing 26 million individuals worldwide and is expanding. Imbalanced redox homeostasis in cardiac cells alters the structure and function of the cells, which leads to contractile dysfunction, myocardial hypertrophy, and fibrosis in chronic heart failure. Various targets and agents acting on these such as siRNA, miRNA, interleukin-1, opioids, vasodilators, and SGLT2 inhibitors are being evaluated for heart failure, and nuclear factor erythroid 2-related factor 2 (NRF2) is one of them. NRF2 is a master transcription factor which is expressed in most of the tissues and exhibits a major role in amplification of the antioxidant pathways associated with the enzymes present in myocardium. Increased ROS generation and PI3K-Akt signaling can activate the receptor NRF2. Various in vitro and in vivo and few clinical studies suggested NRF2 may possess a potential for targeting oxidative stress-induced cardiovascular diseases including heart failures. All these studies collectively propose that upregulation of NRF2 will attenuate the increase in hemodynamic stress and provide beneficial role in cardiovascular diseases. The current review shall familiarize readers about the regulations and functions of NRF2. We have also discussed the current evidences suggesting beneficial role of NRF2 activators in heart failure. Graphical abstract.

Repurposing of sodium valproate in colon cancer associated with diabetes mellitus: Role of HDAC inhibition

BACKGROUND AND PURPOSE

Diabetic patients are at greater risk for colon cancer. Histone deacetylases (HDACs) serve as common target for both. The key objective of the study was to evaluate the effect of sodium valproate in type 2 diabetes mellitus associated colon cancer.

EXPERIMENTAL APPROACH

High fat diet and streptozotocin were used to induce type 2 diabetes. Following this, after diabetes confirmation, colon cancer was induced using 1,2 dimethylhydrazine (25 mg/kg, s.c.) once weekly from 7th week to 20th weeks. Sodium valproate (200 mg/kg) treatment was given from 20th to 24th week. At the end of 24 weeks, several enzymatic and biochemical parameters, were estimated. MTT, clonogenic and scratch wound healing assay were carried out in HCT-15 cell line.

KEY RESULTS

Hyperglycemia, hyperinsulinemia, increase in cytokines (TNF-α and IL-1β) and carcinoembryonic antigen and presence of proliferating cells was seen in disease control animals which was prevented by sodium valproate treatment. Overexpression of relative HDAC2 mRNA levels was found in diseased control animals, which was reduced by sodium valproate treatment. IC₅₀ of sodium valproate was found to be 3.40 mM and 3.73 mM at 48 h and 72 h respectively on HCT-15 cell line. Sodium valproate also dose dependently prevented colony formation and cell migration.

CONCLUSION AND IMPLICATIONS

Sodium valproate can be considered for repurposing in colon cancer associated with diabetes mellitus.

Magnesium valproate ameliorates type 1 diabetes and cardiomyopathy in diabetic rats through estrogen receptors

Estrogen is known to exhibit cardioprotective and antihyperlipidemic action. Valproic acid has been shown to upregulate estrogen receptors (ERs) in breast and prostate cancer tissues. No pharmacological evaluations for magnesium valproate (MgV) so far have been done for diabetic cadio-lipidemic complications. Based on the above context, current study was undertaken to evaluate the therapeutic effectiveness of MgV in cardiac complications associated with type-1 diabetes mellitus in rats wherein diabetes was induced by single tail vein injection of streptozotocin (STZ, 45mg/kg, IV) in female Sprague Dawley rats and treatment of MgV (210mg/kg, PO) was given for eight weeks to diabetic animals, after which, various biochemical and cardiac biomarkers, hypertrophic, hemodynamic and histological parameters along with immunohistochemistry of ERs in the left ventricle (LV) were estimated. MgV treatment significantly controlled hyperglycemia and dyslipidemia, reduced elevated cardiac biomarkers and C-reactive protein(CRP), significantly improved hemodynamic functions and increased the rate of pressure development and decay. MgV also significantly reduced left ventricular hypertrophy index and cardiac hypertrophy index, LV wall thickness, LV collagen, cardiomyocyte diameter and prevented the oxidative stress with significant increase in Na⁺-K⁺-ATPase activity in LV. Moreover, MgV reversed STZ-induced histological alterations and decreased glycogen content in LV and increased the ER_β expressions in LV as evidenced by immunohistochemistry. The result indicated that MgV prevented disease progression in the early stage of diabetic cardiomyopathy which seems to be mediated by upregulation of estrogen receptors in LV tissue.

Selective inhibition of HDAC2 by magnesium valproate attenuates cardiac hypertrophy

The regulatory paradigm in cardiac hypertrophy involves alterations in gene expression that is mediated by chromatin remodeling. Various data suggest that class I and class II histone deacetylases (HDACs) play opposing roles in the regulation of hypertrophic pathways. To address this, we tested the effect of magnesium valproate (MgV), an HDAC inhibitor with 5 times more potency on class I HDACs. Cardiac hypertrophy was induced by partial abdominal aortic constriction in Wistar rats, and at the end of 6 weeks, we evaluated hypertrophic, hemodynamic, and oxidative stress parameters, and mitochondrial DNA concentration. Treatment with MgV prevented cardiac hypertrophy, improved hemodynamic functions, prevented oxidative stress, and increased mitochondrial DNA concentration. MgV treatment also increased the survival rate of the animals as depicted by the Kaplan-Meier curve. Improvement in hypertrophy due to HDAC inhibition was further confirmed by HDAC mRNA expression studies, which revealed that MgV decreases expression of pro-hypertrophic HDAC (i.e., HDAC2) without altering the expression of anti-hypertrophic HDAC5. Selective class I HDAC inhibition is required for controlling cardiac hypertrophy. Newer HDAC inhibitors that are class I inhibitors and class II promoters can be designed to obtain "pan" or "dual" natural HDAC "regulators".

Evaluation of role of telmisartan in combination with 5-fluorouracil in gastric cancer cachexia

BACKGROUND

The objective of the present study was to evaluate the effect of combination of telmisartan with 5-flourouracil (5-FU) in gastric cancer cachexia induced by administering N-methyl-N'-methyl-N-nitrosoguanidine (MNNG).

METHOD

MNND was administered once daily by oral gavage for two weeks, and saturated NaCl (1ml per rat) was then given once every 3days for 4weeks. 5-FU (75mg/kg, i.v.) was administered once three weeks from 7th to 22nd week. From 7th to 22nd week, telmisartan (5mg/kg, p.o.) was also administered along with 5-FU.

RESULT

MNNG produced significant decrease in food intake, body weight, caused hyperglycemia, dyslipidemia, hypertension worsened hemodyanamics, increased cachexia markers and increased tumor markers like lactate dehydrogenase and γ-glutamyltransferase. MNNG also produced oxidative stress in the stomach tissue. Treatment with combination of telmisartan with 5-FU produced significant increase in food intake and body weight, controlled hyperglycemia and dyslipidemia, preserved hemodynamic function, and decreased the cachexia markers while 5-FU alone did not produce any such effects. Further, the combination of telmisartan with 5-FU significantly reduced tumor marker levels, oxidative stress and also significantly decreased the cell proliferation, apoptosis, hyperkeratosis, keratohyaline granules and invasive carcinoma of forestomach and reduced muscle atrophy in tibilias anterior skeletal muscle.

CONCLUSION

Our data suggests that combination of telmisartan with 5-FU treatment is beneficial in controlling cancer cachexia. Telmisartan can be used as an add-on therapy with 5-FU or other traditional chemotherapeutic agents.

The effect of a preparation of minerals, vitamins and trace elements on the cardiac gene expression pattern in male diabetic rats

Background

Diabetic patients have an increased risk of developing cardiovascular diseases, which are the leading cause of death in developed countries. Although multivitamin products are widely used as dietary supplements, the effects of these products have not been investigated in the diabetic heart yet. Therefore, here we investigated if a preparation of different minerals, vitamins, and trace elements (MVT) affects the cardiac gene expression pattern in experimental diabetes.

Methods

Two-day old male Wistar rats were injected with streptozotocin (i.p. 100 mg/kg) or citrate buffer to induce diabetes. From weeks 4 to 12, rats were fed with a vehicle or a MVT preparation. Fasting blood glucose measurement and oral glucose tolerance test were performed at week 12, and then total RNA was isolated from the myocardium and assayed by rat oligonucleotide microarray for 41012 oligonucleotides.

Results

Significantly elevated fasting blood glucose concentration and impaired glucose tolerance were markedly improved by MVT-treatment in diabetic rats at week 12. Genes with significantly altered expression due to diabetes include functional clusters related to cardiac hypertrophy (e.g. caspase recruitment domain family, member 9; cytochrome P450, family 26, subfamily B, polypeptide; FXYD domain containing ion transport regulator 3), stress response (e.g. metallothionein 1a; metallothionein 2a; interleukin-6 receptor; heme oxygenase (decycling) 1; and glutathione S-transferase, theta 3), and hormones associated with insulin resistance (e.g. resistin; FK506 binding protein 5; galanin/GMAP prepropeptide). Moreover the expression of some other genes with no definite cardiac function was also changed such as e.g. similar to apolipoprotein L2; brain expressed X-linked 1; prostaglandin b2 synthase (brain). MVT-treatment in diabetic rats showed opposite gene expression changes in the cases of 19 genes associated with diabetic cardiomyopathy. In healthy hearts, MVT-treatment resulted in cardiac gene expression changes mostly related to immune response (e.g. complement factor B; complement component 4a; interferon regulatory factor 7; hepcidin).

Conclusions

MVT-treatment improved diagnostic markers of diabetes. This is the first demonstration that MVT-treatment significantly alters cardiac gene expression profile in both control and diabetic rats. Our results and further studies exploring the mechanistic role of individual genes may contribute to the prevention or diagnosis of cardiac complications in diabetes.

Electronic supplementary material

The online version of this article (doi:10.1186/s12933-015-0248-6) contains supplementary material, which is available to authorized users.

Beneficial role of tamoxifen in isoproterenol-induced myocardial infarction

ER-α and ER-β agonist 17β-estradiol is reported to attenuate cardiac hypertrophy. Tamoxifen is a selective estrogen receptor modulator. Hence, the objective of this study was to investigate the effects of tamoxifen in myocardial infarction. For this, tamoxifen was administered to Sprague–Dawley rats for 1–14 days, and isoproterenol (ISO) (100 mg·(kg body mass)−1·day−1) was administered subcutaneously on the 13th and 14th days of the study in order to induce myocardial infarction, after which, various biochemical, cardiac, and morphometric parameters were evaluated. ISO produced significant dyslipidemia, hypertension, bradycardia, oxidative stress, and an increase in serum cardiac markers. Treatment with tamoxifen significantly controlled dyslipidemia, hypertension, bradycardia, oxidative stress, and reduced serum cardiac markers. The ISO control rats exhibited significant increases in the infarct size of the left ventricle (LV), LV cavity area, cardiac and LV hypertrophic indices, LV-wall thickness, cardiomyocyte diameter, and area. Treatment with tamoxifen significantly reduced infarction as well as hypertrophic and morphometric parameters. ISO also produced significant increases in the LV collagen level, decreases in Na+K+ATPase activity, and a reduction in the rate of pressure development and decay, which were prevented by tamoxifen treatment. The protective effect of tamoxifen on myocardial infarct was further confirmed by histopathological examination. Our data thus suggest that tamoxifen exerts beneficial effects in ISO-induced myocardial infarction.

Combination of telmisartan with cisplatin controls oral cancer cachexia in rats

The objective of the present investigation was to study the effect of combination of telmisartan with cisplatin in oral cancer cachexia induced by applying 0.5% 4-nitroquinoline-1-oxide (4-NQO) in propylene glycol to tongue, thrice a week for 8 weeks. From 8th to 22nd week, cisplatin (0.23 mg/kg, i.v.) was administered once in three weeks and telmisartan (5 mg/kg/day, p.o.) was administered daily. 4-NQO produced significant decrease in food intake, body weight, hyperglycemia, dyslipidemia, hypertension, and bradycardia, worsened hemodyanamics, increased cachexia markers like insulin, C-reactive protein, and interleukin-6, and increased tumor markers like lactate dehydrogenase and γ-glutamyl transferase.Treatment with combination of telmisartan with cisplatin produced significant increase in food intake and body weight and controlled hyperglycaemia and dyslipidemia, preserved hemodynamic function, and decreased the cachexia markers while cisplatin alone did not produce any increase in food intake and body weight. Further, the combination of telmisartan with cisplatin significantly reduced tumor marker levels. Combination of telmisartan with cisplatin prevented 4-NQO induced oxidative stress, hyperplasia and hyperkeratosis, premalignant dysplasia, and invasive squamous cell carcinoma in the tongue. Our data suggests that combination of telmisartan with cisplatin treatment is beneficial in controlling cancer cachexia. Telmisartan can be used as an add-on therapy with cisplatin or other traditional chemotherapeutic agents.