Kaempferol protects against doxorubicin-induced cardiotoxicity in vivo and in vitro

Despite Blocking Doxorubicin-Induced Vascular Damage, Quercetin Ameliorates Its Antibreast Cancer Activity

Quercetin is a naturally occurring flavonol present in many foods. Doxorubicin is an effective anticancer agent despite its dose-limiting cardiovascular toxicity. Herein, we investigated the potential protective effects of quercetin against doxorubicin-induced vascular toxicity and its effect on the therapeutic cytotoxic profile of doxorubicin in breast cancer cell lines. The incubation of isolated aortic rings with doxorubicin produced concentration-dependent exaggeration of vasoconstriction responses to phenylephrine but impaired vasodilation responses to acetylcholine. Coincubation with quercetin completely blocked the exaggerated vasoconstriction responses and the impaired vasodilation. In addition, doxorubicin incubation increased reactive oxygen species generation from the isolated aorta, while coincubation with quercetin inhibited ROS generation back to normal values. On the other hand, quercetin in combination with doxorubicin, doubled the IC₅₀ of doxorubicin alone in MCF-7 cells from 0.4 ± 0.03 to 0.8 ± 0.06 μM. To a lesser extent, the IC₅₀ of doxorubicin did not change after combination with quercetin in MDA-MB-231 cells. These findings indicate a significant antagonistic interaction between quercetin and doxorubicin in the aforementioned cell lines. Only in T47D cells, quercetin combination with doxorubicin was an additive interaction (CI − value = 1.17). Yet, quercetin significantly impaired the immediate phase of intracellular ROS generation by doxorubicin within breast cancer cells from 125.2 ± 3.6% to 102.5 ± 3.9% of control cells. Using annexin-V/FITC staining technique, the quercetin/doxorubicin combination showed a significantly lower percent of apoptotic cells compared to doxorubicin alone treated cells. Cell cycle distribution in breast cancer cells was performed using DNA content flowcytometry after propidium iodide staining. Quercetin induced significant accumulation of cells in the S phase as well as in the G₂/M phase within both MCF-7 and MDA-MB-231 cell lines and interfered with doxorubicin-induced cell cycle effects. Interestingly, quercetin was found to inhibit the P-glycoprotein ATPase subunit with a consequent enhanced intracellular concentration of doxorubicin in MDA-MB-231 and T47D cells. In conclusion, quercetin, despite its potent vascular protective activity against doxorubicin, was found to influence doxorubicin-induced antibreast cancer effects via pharmacodynamic as well as cellular pharmacokinetic aspects.

Neonatal administration of kaempferol does not alter satiety but increases somatic growth and reduces adiposity in offspring of high-fat diet dams

AIM

The aim of this study was to evaluate the effects of maternal exposure to a high-fat diet associated with neonatal administration of kaempferol on somatic growth, biochemical profile and feeding behavior in offspring.

MATERIALS AND METHODS

Wistar rats were distributed according to diet during pregnancy and lactation into Control (C; 3.4 kcal/g; 12% kcal/lipids) or High-fat (HFD; 4.6 kcal/g; 51% kcal/lipids) groups. In the offspring, vehicle (V) or kaempferol (K, 1 mg/kg) were administered from the 8th until the 21st postnatal day (PND). Maternal body weight (BW), caloric intake and adiposity were measured. In the offspring, somatic growth parameters were evaluated on the 7th, 14th, 21st, 25th and 30th PND, except for BW, which was measured from the 8th to the 21st and from the 25th to the 30th PND. Feeding behavior was assessed by food intake and behavioral satiety sequence (BSS) on the 30th PND. The biochemical profile and relative weight of adipose tissue of offspring were also measured.

KEY FINDINGS

Dams exposed to HFD showed no difference in body weight and caloric intake but exhibited increased adiposity. Neonatal administration of kaempferol increased body weight after weaning and somatic growth in the offspring of HFD dams. Neonatal kaempferol also reduced adiposity and serum creatinine levels in offspring. Neither maternal diet nor kaempferol altered offspring feeding behavior.

SIGNIFICANCE

Neonatal administration of kaempferol promotes increased somatic growth post-weaning, reduces adiposity, and does not alter feeding behavior in offspring from high-fat dams.

Flavonoids and Mitochondria: Activation of Cytoprotective Pathways?

A large number of diverse mechanisms that lead to cytoprotection have been described to date. Perhaps, not surprisingly, the role of mitochondria in these phenomena is notable. In addition to being metabolic centers, due to their role in cell catabolism, ATP synthesis, and biosynthesis these organelles are triggers and/or end-effectors of a large number of signaling pathways. Their role in the regulation of the intrinsic apoptotic pathway, calcium homeostasis, and reactive oxygen species signaling is well documented. In this review, we aim to characterize the prospects of influencing cytoprotective mitochondrial signaling routes by natural substances of plant origin, namely, flavonoids (e.g., flavanones, flavones, flavonols, flavan-3-ols, anthocyanidins, and isoflavones). Flavonoids are a family of widely distributed plant secondary metabolites known for their beneficial effects on human health and are widely applied in traditional medicine. Their pharmacological characteristics include antioxidative, anticarcinogenic, anti-inflammatory, antibacterial, and antidiabetic properties. Here, we focus on presenting mitochondria-mediated cytoprotection against various insults. Thus, the role of flavonoids as antioxidants and modulators of antioxidant cellular response, apoptosis, mitochondrial biogenesis, autophagy, and fission and fusion is reported. Finally, an emerging field of flavonoid-mediated changes in the activity of mitochondrial ion channels and their role in cytoprotection is outlined.

Network Pharmacology-Based Exploration of Synergistic Mechanism of Guanxin II Formula (II) for Coronary Heart Disease

OBJECTIVE

To study the pharmacological mechanism of Guanxin II formula (II) for treatment of coronary heart disease (CHD).

METHODS

A network pharmacology-based method was utilized. First candidate compounds, targets of GX II were collected using PharmMapper, BATMAN-TCM, DrugBank and SwissTargetPrediction, and targets on CHD were mined from GeneCards, DisGenet, DrugBank and GEO. Afterwards, the big hub compounds and targets were chosen in the candidate compounds-direct therapeutic targets on the CHD (C-T) network and the direct therapeutic targets on the CHD (T-D) network. Furthermore, the Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analysis were performed to identify the enriched terms. Finally, a molecular docking simulation strategy was adopted to verify the binding capacity between the big hub compounds and big hub targets on CHD.

RESULTS

First, 114 candidate compounds were selected with the following criteria: OB⩾30%, DL⩾0.18, and HL ⩾4 h. Then, 1,035 targets of GX II were gathered, while 928 targets on CHD were collected. Afterwards, 196 common targets of compound targets and therapeutic targets on CHD were defined as direct therapeutic targets acting on CHD. In addition, the contribution index (CI) in the C-T network was calculated, and 4 centrality properties, including degree, betweenness, closeness and coreness, in the T-D network, 4 big hub compounds, and 6 big hub targets were eventually chosen. Furthermore, the GO and KEGG analysis indicated that GX II acted on CHD by regulating the reactive oxygen species metabolism, steroid metabolism, lipid metabolism, inflammatory response, proliferation, differentiation and apoptosis. The docking results manifested excellent binding capacity between the 4 big hub compounds and 6 big hub targets on CHD.

CONCLUSION

This network pharmacology-based exploration revealed that GX II might prevent and inhibit the primary pathological processes of CHD.

Protection from doxorubicin-induced nephrotoxicity by clindamycin: novel antioxidant, anti-inflammatory and anti-apoptotic roles

This study was performed to examine whether clindamycin could protect against doxorubicin (DOX)-induced acute nephrotoxicity, and if so, what molecular mechanisms responsible for this protective effect. Male albino rats were pretreated with clindamycin once per day for 5 consecutive days at a dose of 300 mg/kg, i.p, then received a single dose of DOX (15 mg/kg; i.p) on the 5th day. DOX-induced marked renal injury as indicated by the presence of inflammatory cell infiltration, congestion, and edema accompanied by elevation in serum levels of creatinine and urea. These effects were alleviated by clindamycin pretreatment. DOX caused glutathione depletion and reduction in level of the antioxidant enzyme, catalase. Pretreatment with clindamycin markedly prohibited DOX-induced oxidative damage in renal tissue. Moreover, DOX provoked inflammatory responses in renal tissues as confirmed by increased expressions of NF-κB and COX-2 which were significantly reduced by clindamycin pretreatment. Besides, DOX-triggered apoptotic cascades in renal tissues as evidenced by elevated expression of pro-apoptotic proteins; Bax and cytochrome c, enhancing activity of caspase-3 enzyme whereas reducing the expression of anti-apoptotic Bcl-2 protein. Clindamycin pretreatment counteracts these apoptotic effects of DOX. Summarily, our results provide an evidence for the first time that clindamycin has a potential protective action against DOX-induced acute nephrotoxicity through inhibiting oxidative stress, inflammatory cascades, and apoptotic tissue injury.

Tannic Acid: Specific Form of Tannins in Cancer Chemoprevention and Therapy-Old and New Applications

Purpose of Review

This short review is aimed at providing an updated and comprehensive report on tannic acid biological activities and molecular mechanisms of action most important for cancer prevention and adjuvant therapy.

Recent Findings

Tannic acid (TA), a mixture of digallic acid esters of glucose, is a common ingredient of many foods. The early studies of its anti-mutagenic and anti-tumorigenic activity were mostly demonstrated in the mouse skin model. This activity has been explained by its ability to inhibit carcinogens activation, as well as antioxidant and anti-inflammatory properties. Recently, the cell cycle arrest, apoptosis induction, reduced rate of proliferation, and cell migration and adhesion of several cancer cell lines as a result of TA treatment were described. The underlining mechanisms include modulation of signaling pathways such as EGFR/Jak2/STATs, or inhibition of PKM2 glycolytic enzyme. Moreover, epithelial-to-mesenchymal transition prevention and decrease of cancer stem cells formation by TA were also reported. Besides, TA was found to be potent chemosensitizer overcoming multidrug resistance. Eventually, its specific physicochemical features were found useful for generation of drug-loaded nanoparticles.

Summary

TA was shown to be a very versatile molecule with possible application not only in cancer prophylaxis, as was initially thought, but also in adjuvant cancer therapy. The latter may refer to chemosensitization and its application as a part of drug delivery systems. More studies are required to better explore this subject. In addition, the effect of TA on normal cells and its bioavailability have to better characterized.

Kaempferol protects mitochondria and alleviates damages against endotheliotoxicity induced by doxorubicin

Kaempferol (Kae), a flavonoid, has been found in fruits and other vegetables, possesses many biological activities. 14-3-3 protein exerts protection on various types of injured tissues and cells. Doxorubicin (Dox) causes excessive reactive oxygen species (ROS) generation, which induces endotheliotoxicity and cardiotoxicity. We hypothesized that Kae could protect vascular endothelium by regulating 14-3-3γ or related pathways against Dox toxicity. HUVECs were established Dox-toxic injury models. Kae's effects were assessed with many physiological, enzymatic, cellular, and molecular biological indexes. Our results showed that Dox-induced damage in HUVECs were reduced through Kae to promote the expression of total protein 14-3-3γ and mitochondrial Bcl-2, phosphorylate Bad, increase cell viability, NO content, DDAHⅡactivity, p-eNOS/eNOS ratio, and MMP levels, maintained NAD⁺/NADH and GSH/GSSG balance, and decrease LDH and caspase-3 activities, ADMA content, ROS generation, mPTP openness, and apoptosis. Kae's effects were abolished with pAD/14-3-3γ-shRNA downregulating 14-3-3γ expression, or ABT-737 inhibiting Bcl-2 activity. This study demonstrated that Kae protected the vascular endothelium against Dox-induced damage by regulating 14-3-3γ and ADMA/DDAHⅡ/eNOS/NO pathway, inhibiting oxidative stress, and improving mitochondrial function.

Effect of ghrelin on VEGF-B and connexin-43 in a rat model of doxorubicin-induced cardiomyopathy

Background Since their discovery in the early 1960s, doxorubicin (DOX) remains the most effective anticancer drug. However, this drug has confirmed to be a double-edged sword because it causes a cardiomyopathy that leads to congestive heart failure. Ghrelin, a multi-functional peptide, plays an important role in cardiovascular protection. Therefore, we investigated the effects of ghrelin on vascular endothelial growth factor-beta (VEGF-B) and connexin-43 (Cx43) expression in DOX-induced cardiomyopathy. Methods Forty adult male rats were divided randomly into four groups: normal, normal + ghrelin, DOX-induced cardiomyopathy, and DOX-induced cardiomyopathy + ghrelin. Biochemical and histopathological analysis, electrocardiograph (ECG), heart rate, systolic blood pressure (SBP), and immunohistochemical staining of VEGF-B and Cx43 were assessed for all rats in heart tissue specimens. The duration of the study was 2 weeks. Results DOX-induced cardiomyopathy in rats showed significant ECG changes such as prolongation of PR, QT, QTC intervals and ST segment, a decrease in amplitude and an increase in the duration of QRS complex, bradycardia, and a decrease in SBP. Also, rats in the DOX group showed myocardial histopathological damage in the form of severe fibrosis with decreased expression of Cx43 and a non-significant difference in expression of VEGF-B when compared to normal rats. Treatment with ghrelin resulted in a significant improvement in all the studied parameters and was associated with an increase in VEGF-B and Cx43 expression. Conclusions Ghrelin has a beneficial effect against DOX-induced cardiomyopathy which may be mediated through VEGF-B and Cx43 expression in the myocardium. Ghrelin is a promising cardioprotective drug in DOX-induced cardiomyopathy patients, but further studies are needed to evaluate its use.

Recent progress regarding kaempferol for the treatment of various diseases

Kaempferol, also known as kaempferol-3 or kaempferide, is a flavonoid compound that naturally occurs in tea, as well as numerous common vegetables and fruits, including beans, broccoli, cabbage, gooseberries, grapes, kale, strawberries, tomatoes, citrus fruits, brussel sprouts, apples and grapefruit. The present review mainly summarizes the application of kaempferol in treating diseases and the underlying mechanisms that are currently being studied. Due to its anti-inflammatory properties, it may be used to treat numerous acute and chronic inflammation-induced diseases, including intervertebral disc degeneration and colitis, as well as post-menopausal bone loss and acute lung injury. In addition, it has beneficial effects against cancer, liver injury, obesity and diabetes, inhibits vascular endothelial inflammation, protects the cranial nerve and heart function, and may be used for treating fibroproliferative disorders, including hypertrophic scar.

Antioxidant and nephroprotection activities of Combretum micranthum: A phytochemical, in-vitro and ex-vivo studies

Management of chronic renal failure is exceedingly expensive. Despite of encouraging experimental outcomes, there is a lack of potent nephroprotective drugable molecules in a clinics or market. To develop a nephroprotective phytomedicine, the present study was designed to do a literature survey on reported phytochemical and biological analysis of Combretum micranthum and to carry out chemoprofiling, in-vitro antioxidant and ex-vivo nephroprotective capacity of the title plant. The phytochemical and biological activity survey of C. micranthum has reveals the presence of many bioactive compounds such as flavonoids, terpenoids, steroids and alkaloids with many biological activities. Phytochemical investigation re-confirmed the presence of these compounds. Hydroalcoholic extract of C. micranthum (CM extract) showed a strong antioxidant activity by scavenging AAPH, DPPH, nitric oxide, hydrogen peroxide and chelating metal ions. CM extract exhibited significant (P < 0.001) dose dependent inhibition of ferric chloride-ascorbic acid induced lipid peroxidation. Diabetic nephropathy is a serious and common complication leading to end stage renal disease. Therefore, in the present study, glucose-induced toxicity was also studied in human embryonic kidney cells (HEK-293) as an in vitro model for diabetic nephropathy. The results showed that exposure of cells to high glucose (100 mM) for 72 h significantly reduced the cell viability resulting in morphological changes such as cell shrinkage, rounded cell shape and cytoplasmic vacuolation. Treatment with CM extract at 10 and 25 μg/mL resulted in significant improvement in cell viability from 10 to 23% compared to the high glucose control. This study demonstrated the potential antioxidant and nephroprotective properties of C. micranthum, justifying its traditional use in the treatment of various diseases.

Chromatographic Analysis and Anti-Oxidative Property of Naoxinqing Tablet, a Proprietary Preparation of Diospyros Kaki Leaves

The Naoxinqing (NXQ) tablet is a standardised proprietary herbal product containing an extract of persimmon leaves (Diospyros kaki) for the management of cardio- and cerebrovascular diseases. Although previous reports suggested that the efficacy of NXQ is at least partly mediated by its anti-oxidative property, the anti-oxidative effect of the major components of NXQ has not been studied systematically. For quality control purposes, only analytical methods limited to 3 marker analytes have been reported, the extent to which the other components affect efficacy has not been explored. In this study, we developed an ultra-performance liquid chromatography-tandem mass spectrometry (UPLC MS/MS) method for the identification of seven analytes (kaempferol-3-O-glucoside (astragalin), quercetin-3-O-galactoside (hypericin), quercetin-3-O-glucoside (isoquercitin), kaempferol, 3,4-dihydroxybenzoic acid (protocatechuic acid), and furan-2-carboxylic acid (pyromucic acid) and quercetin) in the NXQ. This is the first method reported and validated for the quantification of the seven major secondary metabolites in NXQ. The results for the quantified analytes were then compared in 15 different batches of NXQ. The variation observed in the seven components highlights the need to quantify key bioactive components to ensure product consistency. Radical scavenging activity and abundance was used to rank the analytes. The anti-oxidative effects of NXQ were examined using cultured human vascular endothelial cells (EA.hy926). Corrected 2,2-di(4-tert-octylphenyl)-1-picrylhydrazyl (DPPH) activity results revealed that quercetin and kaempferol have the strongest anti-oxidant capacity in the extract. Both quercetin and kaempferol significantly inhibited the hydrogen peroxide (H₂O₂)-induced EA.hy926 cell injury and intracellular reactive oxygen species (ROS) generation. In conclusion, we established and validated an UPLC-MS/MC method for the analysis of major bioactive components in the NXQ and demonstrated that its anti-oxidative property may play a critical role in cerebrovascular protection.

The protective effect of kaempferol on heart via the regulation of Nrf2, NF-κβ, and PI3K/Akt/GSK-3β signaling pathways in isoproterenol-induced heart failure in diabetic rats

This study was designed to delineate the effect of kaempferol (KF) on heart failure (HF) in diabetic rats. Streptozotocin-induced male diabetic rats received KF orally at 10 and 20 mg/kg for 42 consecutive days. In last 2 days of the experimental period, isoproterenol was subcutaneously injected at 85 mg/kg to induce HF. The hearts were processed for hemodynamic, biochemical, molecular, and histological investigations. Systolic blood pressure, diastolic blood pressure, and mean arterial blood pressure were elevated in KF-treated HF-induced diabetic rats. Moreover, KF treatment resulted in decreased fasting blood glucose and glycosylated hemoglobin levels with increased serum insulin levels. Besides, serum cardiac injury markers like troponin-I, creatine kinase-muscle/brain, lactate dehydrogenase, and brain natriuretic peptide levels were significantly reduced in KF treatment. KF treatment has shown decrease in cardiac heme oxygenase-1, nuclear factor erythroid 2-related factor 2 (Nrf-2), and γ-glutamylcysteine synthetase with increased Keap1 mRNA levels. The cardioprotection of KF was improved by inhibition of apoptosis via blocking phosphorylation of Akt/glycogen synthase kinase (GSK)-3β and p38 mitogen-activated protein-kinase/extracellular signal-regulated kinases signaling pathways in HF-induced diabetic rats. Moreover, reduced cardiac apoptosis in KF treatment was confirmed by decreased terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) positive cells, histopathological changes in HF-induced diabetic rats. Therefore, the cardioprotective effect of KF is attributed to the regulation of Nrf2, nuclear factor kappa-light-chain-enhancer of activated B cells, and Akt/GSK-3β signaling pathways in HF-induced diabetic rats.

Metabolic engineering of microbial cell factories for production of nutraceuticals

Metabolic engineering allows for the rewiring of basic metabolism to overproduce both native and non-native metabolites. Among these biomolecules, nutraceuticals have received considerable interest due to their health-promoting or disease-preventing properties. Likewise, microbial engineering efforts to produce these value-added nutraceuticals overcome traditional limitations of low yield from extractions and complex chemical syntheses. This review covers current strategies of metabolic engineering employed for the production of a few key nutraceuticals with selecting polyunsaturated fatty acids, polyphenolic compounds, carotenoids and non-proteinogenic amino acids as exemplary molecules. We focus on the use of both mono-culture and co-culture strategies to produce these molecules of interest. In each of these cases, metabolic engineering efforts are enabling rapid production of these molecules.

β-Caryophyllene, a natural bicyclic sesquiterpene attenuates doxorubicin-induced chronic cardiotoxicity via activation of myocardial cannabinoid type-2 (CB2) receptors in rats

The cannabinoid type 2 receptor (CB₂) has recently emerged as an important therapeutic target for cancer as well as cardiovascular diseases. The CB₂ receptor downregulation has been reported in solid tumors and cardiovascular diseases, therefore the CB₂ receptor activation has been considered as a viable strategy for chemotherapy as well as cardioprotection. Doxorubicin (DOX) is an important drug that continues to be the mainstay of chemotherapy in solid tumors, leukemia, and lymphoma. However, the use of DOX is often limited due to its lethal cardiotoxicity. Considering the role of CB₂ receptors in cardiovascular diseases and cancer, the activation of CB₂ receptors may protect against DOX-induced chronic cardiotoxicity in rats. In the present study, we investigated the cardioprotective effect of a selective CB₂ receptor agonist; β-Caryophyllene (BCP), a natural bicyclic sesquiterpene, against DOX-induced chronic cardiotoxicity in rats. AM630, a CB₂ receptor antagonist was administered as a pharmacological challenge prior to BCP treatment to demonstrate CB₂ receptor mediated cardioprotective mechanism of BCP. DOX (2.5 mg/kg) was injected intraperitoneally once a week for five weeks to induce chronic cardiotoxicity in rats. BCP was also injected into rats six days a week for a total duration of five weeks. DOX induced a significant decline in cardiac function and oxidative stress evidenced by the depletion of antioxidant enzymes, glutathione, and increased lipid peroxidation. DOX also triggered activation of nuclear factor kappa B (NF-κB) and increased the levels of pro-inflammatory cytokines (TNF-α, IL-6, and IL-1β) and expression of the inflammatory mediators (iNOS and COX-2) in the heart. Furthermore, DOX also upregulated the expression of pro-apoptotic markers such as Bax, p53, cleaved PARP, active caspase-3 and downregulated anti-apoptotic marker Bcl-2 in the myocardium. BCP treatment exerted significant cardioprotective effect by salvaging the heart tissues, improving cardiac function, mitigating oxidative stress, inflammation, and apoptosis. The histological and ultrastructural studies also appear in line with our findings of biochemical and molecular parameters. The CB₂ receptor-mediated cardioprotective mechanism was further confirmed by the abrogation of the beneficial effects of BCP with prior administration of the CB₂ receptor antagonist; AM630. Our study revealed the novel mechanism of BCP in cardioprotection against DOX-induced chronic cardiotoxicity by the activation of CB₂ receptors.

Effect of Kaempferol Pretreatment on Myocardial Injury in Rats

The present study was undertaken to evaluate the effect of kaempferol in isoprenaline (ISP)-induced myocardial injury in rats. ISP was administered subcutaneously for two subsequent days to induce myocardial injury. Assessment of myocardial injury was done by estimation of hemodynamic functions, myocardial infarcted area, cardiac injury markers, lipid profile, oxidative stress, pro-inflammatory cytokines and histopathology of heart and liver. Rats pretreated with kaempferol showed reduction in the myocardial infarcted area and heart rate. However, no improvement was observed in change in body weight, mean arterial, systolic and diastolic blood pressure. Kaempferol showed significant decrease in serum LDH, CK-MB, troponin-I and lipid profile. However, highest dose of kaempferol did not reduce the serum triglyceride level. Further, antioxidant enzymes, SOD and catalase, were also higher. However, reduced glutathione, serum SGOT and creatinine did not show any improvement. Kaempferol showed reduction in MDA level. Kaempferol at highest dose showed reduction in pro-MMP-2 expression and MMP-9 level. mRNA expression level of TNF-α was not different in kaempferol-pretreated myocardial injured rats with ISP-alone group. Pretreatment with kaempferol at highest dose showed mild mononuclear infiltration and degenerative changes in heart tissue section of myocardial injured rats. Rats pretreated with kaempferol at higher concentration showed normal cordlike arrangement of hepatocytes with moderate swelling of hepatocytes (vacuolar degeneration) around the central vein. Study suggests that kaempferol attenuated lipid profile, infarcted area and oxidative stress in ISP-induced myocardial injury in rats.

Pristimerin protects against doxorubicin-induced cardiotoxicity and fibrosis through modulation of Nrf2 and MAPK/NF-kB signaling pathways

Background/purpose

Pristimerin (Pris) is triterpenoid compound with many biological effects. Until now, nothing is known about its effect on doxorubicin (DOX)-induced cardiotoxicity. Hence, this study investigated the impact of Pris on DOX-induced cardiotoxic effects.

Materials and methods

Rats were treated with Pris 1 week before and 2 weeks contaminant with repeated DOX injection. Afterwards, electrocardiography (ECG), biochemical, histopathological, PCR, and Western blot assessments were performed.

Results

Pris effectively alleviated DOX-induced deleterious cardiac damage. It inhibited DOX-induced ECG abnormities as well as DOX-induced elevation of serum indices of cardiotoxicity. The histopathological cardiac lesions and fibrosis were remarkably improved in Pris-treated animals. Pris reduced hydroxyproline content and attenuated the mRNA and protein expression of the pro-fibrogenic genes. The antioxidant activity of Pris was prominent through the amelioration of oxidative stress parameters and enhancement of antioxidants. Furthermore, Pris enhanced the activation of nuclear factor-erythroid 2 related factor 2 (Nrf2) signaling pathway as it increased the mRNA and protein expression of Nrf2 and Nrf2-dependent antioxidant genes (GCL, NQO1, HO-1). Additionally, the anti-inflammatory effect of Pris was obvious through the inhibition of mitogen activated protein kinase (MAPK)/nuclear factor kappa-B (NF-kB) signaling and subsequent inhibition of inflammatory mediators.

Conclusion

This study provides evidence of the cardioprotective activity of Pris which is related to the modulation of Nrf2 and MAPK/NF-kB signaling pathways.

Yiqi Fumai lyophilized injection attenuates doxorubicin-induced cardiotoxicity, hepatotoxicity and nephrotoxicity in rats by inhibition of oxidative stress, inflammation and apoptosis

Doxorubicin (DOX) is one of the most effective antineoplastic drugs, however, its organ toxicity inhibits the clinical utility. This study was aimed at investigating the protective effects of Yiqi Fumai lyophilized injection (YQFM) against DOX-induced tissue injury and exploring the mechanisms which mediated reactive oxygen species (ROS), inflammation and apoptosis. The experiment was as follows: rats were subjected to an intraperitoneal injection (i.p.) of YQFM (0.481 g kg-1, i.p.) for 12 days; DOX (5 mg kg-1, i.p.) was administered on the 4th, 8th and 12th days to achieve a cumulative dose of 15 mg kg-1. Pretreatment of YQFM significantly ameliorated intracellular damage and dysfunction of the heart, liver and kidneys via decreasing activities of injury indexes. The levels of lipid peroxidation and glutathione depletion were clearly reduced following YQFM pretreatment, meanwhile the activities of glutathione peroxidase, superoxide dismutase, and catalase were elevated. Additionally administering YQFM could mitigate the cardiotoxicity, hepatotoxicity and nephrotoxicity via reducing levels of inflammatory factors and decreasing apoptosis. Accordingly, this study indicated that YQFM attenuated DOX-induced toxicity by ameliorating organ function, decreasing ROS production, and preventing excessive inflammation and apoptosis.

Apoptosis in angiotensin II-stimulated hypertrophic cardiac cells -modulation by phenolics rich extract of Boerhavia diffusa L

Herein, we investigated the effects of B. diffusa (BDE), a well-known cardiotonic edible medicinal plant against apoptosis in Angiotensin II (Ang II)-stimulated hypertrophic cardiac cells (H9c2). The cells were analyzed for viability, markers of hypertrophy, apoptosis, and the expression of various proteins related to apoptosis. Ang II (100 nM for 48 h)-exposed H9c2 cells treated with BDE (75 μg/ml) showed a significant reduction in apoptosis (58.60%↓) compared to Ang II-alone treated cells. BDE treatment significantly reduced the up-regulation of Bax and cytosolic cytochrome-C caused by Ang II as well as reduced the degree of Ang II- induced down-regulation of Bcl-2. A reduction in caspase-3 activity (33.77%↓) and down-regulation of TNF-α was also observed in BDE treated cells stimulated with Ang II. Furthermore, the up-regulation of phospho-p38 MAPK was attenuated by BDE treatment. Bioactive components in the extract were identified as boeravinone B, quercetin, kaempferol, and caffeic acid as evident from high-performance liquid chromatography (HPLC). Overall, our study shows that B. diffusa is effective in attenuating apoptosis in cardiac cells, which is a major contributor to sudden cardiac death in addition to its nutraceutical properties.

Effect of fermented Cordyceps sinensis on doxorubicin‑induced cardiotoxicity in rats

Cordyceps sinensis (CS) is a prominent medicinal herb in traditional Chinese medicine, and fermented CS is frequently used as a substitute for natural CS. Doxorubicin (DOX), an antitumor drug used in chemotherapy, is limited by its poor cardiotoxicity. The aim of the present study was to evaluate the protective effect of fermented CS against DOX-induced cardiotoxicity and the potential underlying mechanisms. Male Sprague-Dawley rats (180–200 g) were randomly assigned to seven different treatment groups: Normal control, DOX control, DOX+captopril (0.05 g/kg), 0.75, 1.5 and 3 g/kg DOX+CS, and the CS (1.5 g/kg) control. Histopathological changes, cardiac energy metabolism, cyclic adenosine monophosphate (cAMP) signaling and the associated mRNA expression of AMP-activated protein kinase (AMPK) were then evaluated. Fermented CS decreased the left ventricular weight index, heart weight index and mortality; however, it increased diastolic blood pressure and mean arterial pressure. In addition, it shortened the duration of the QRS complex and Sα-T segment, decreased serum creatine kinase (CK) and aspartate aminotransferase activity, inhibited histopathological changes and reduced brain natriuretic peptide content. Treatment with fermented CS also increased the activities of superoxide dismutase and glutathione peroxidase, reduced malondialdehyde content, increased the mitochondrial activities of Na⁺K⁺-adenosine 5′-triphosphate (ATP) ase, Ca²⁺Mg²⁺-ATPase and CK, and increased the creatine phosphate/ATP ratio and AMP/ATP ratio. Furthermore, it decreased the ATP/adenosine 5′-diphosphate (ADP) ratio, upregulated AMPKα2 expression, reduced the activity of serum phosphodiesterases (PDEs) and increased myocardial cAMP content. The results of the present study demonstrated that fermented CS attenuated DOX-induced cardiotoxicity by inhibiting myocardial hypertrophy and myocardial damage, ameliorating systolic function and the antioxidant enzyme system, improving cardiac energy metabolism, depressing the activities of PDEs, and by upregulating the cAMP and AMPK signaling pathways. Thus, fermented CS may be a candidate for the prevention of DOX-induced cardiotoxicity, cardiac energy impairment and against a number of cardiac diseases.

Mitochondria-Targeting Small Molecules Effectively Prevent Cardiotoxicity Induced by Doxorubicin

Doxorubicin (Dox) is a chemotherapeutic agent widely used for the treatment of numerous cancers. However, the clinical use of Dox is limited by its unwanted cardiotoxicity. Mitochondrial dysfunction has been associated with Dox-induced cardiotoxicity. To mitigate Dox-related cardiotoxicity, considerable successful examples of a variety of small molecules that target mitochondria to modulate Dox-induced cardiotoxicity have appeared in recent years. Here, we review the related literatures and discuss the evidence showing that mitochondria-targeting small molecules are promising cardioprotective agents against Dox-induced cardiac events.

Sardine oil loaded vanillic acid grafted chitosan microparticles, a new functional food ingredient: attenuates myocardial oxidative stress and apoptosis in cardiomyoblast cell lines (H9c2)

Fish oil has been widely recognized as an excellent dietary source of polyunsaturated n-3 fatty acids such as EPA and DHA. However, it can undergo oxidation easily resulting in the formation of toxic off flavor compounds such as hydroperoxides. These compounds adversely affect the nutritional quality and may induce several stress reactions in body. To solve this problem, a new antioxidant bio-material, vanillic acid-grafted chitosan (Va-g-Ch), was synthesized and used as a wall material for microencapsulation of fish oil. The sardine oil loaded Va-g-Ch microparticles could be a potential functional food ingredient considering the numerous health benefits of fish oil, chitosan, and vanillic acid. The current study aimed to investigate the possible protective effect of sardine oil-loaded Va-g-Ch microparticles against doxorubicin-induced cardiotoxicity and the underlying mechanisms. In vitro cytotoxicity evaluation was conducted using H9c2 cardiomyocytes. MTT assay revealed that effective cytoprotective effect was induced by a sample concentration of 12.5 μg/mL. Results of apoptosis by double fluorescent staining with acridine orange/ethidium bromide and caspase-3 evaluation by ELISA substantiated the above findings. Further, flow cytometric determination of membrane potential, relative expression of NF-κB by PCR, and ROS determination using DCFH-DA also confirmed the protective effect of encapsulated sardine oil against doxorubicin-induced cardiotoxicity. NF-κB expression was down-regulated nearly by 50% on cells treated with encapsulated sardine oil. Altogether, the results revealed that sardine oil-loaded Va-g-Ch microparticles demonstrated potential cell protection against doxorubicin-induced oxidative stress.

Recent progress in doxorubicin-induced cardiotoxicity and protective potential of natural products

BACKGROUND

As an anthracycline antibiotic, doxorubicin (DOX) is one of the most potent and widely used chemotherapeutic agents for various types of solid tumors. Unfortunately, clinical application of this drug results in severe side effects of cardiotoxicity.

PURPOSE

We aim to review the research focused on elimination or reduction of DOX cardiotoxicity without affecting its anticancer efficacy by natural products.

METHODS

This study is based on pertinent papers that were retrieved by a selective search using relevant keywords in PubMed and ScienceDirect. The literature mainly focusing on natural products and herb extracts with therapeutic efficacies against experimental models both in vitro and in vivo was identified.

RESULTS

Current evidence revealed that multiple molecules and signaling pathways, such as oxidative stress, iron metabolism, and inflammation, are associated with DOX-induced cardiotoxicity. Based on these knowledge, various strategies were proposed, and thousands of compounds were screened. A number of natural products and herb extracts demonstrated potency in limiting DOX cardiotoxicity toward cultured cells and experimental animal models.

CONCLUSIONS

Though a panel of natural products and herb extracts demonstrate protective effects on DOX-induced cardiotoxicity in cells and animal models, their therapeutic potentials for clinical needs further investigation.

Antioxidant and Protective Effects of Schinus terebinthifolius Raddi Against Doxorubicin-Induced Toxicity

Doxorubicin is an anticancer drug whose toxic effects on non-cancer cells are associated with increased oxidative stress. This study investigated the chemical composition, antioxidant activity of the methanolic extract of Schinus terebinthifolius Raddi leaves (MESL) as well as effects against doxorubicin-induced toxicity in human erythrocytes, K562 human erythroleukemia cells, and mouse hearts. The chemical composition indicated the presence of phenolic compounds, flavonoids, tannins, and ascorbic acid. MESL showed antioxidant activity by scavenging free radicals and inhibiting hemolysis and lipid peroxidation in human erythrocytes incubated with an oxidizing agent, and was able to increase the enzymatic activity of superoxide dismutase and glutathione peroxidase in human erythrocytes, without influencing the activity of enzyme catalase. The increase of oxidative hemolysis and malondialdehyde levels in erythrocytes incubated with doxorubicin was reduced by treatment with MESL. The cytotoxic activity of doxorubicin in erythroleukemia cells treated with MESL was unmodified. Additionally, the extract protected mice against the doxorubicin-induced cardiotoxicity. In conclusion, the MESL exhibits antioxidant activity, reducing doxorubicin-induced oxidative stress without changing the anticancer action of the drug, and protects against doxorubicin-induced cardiotoxicity. Hence, these findings suggest that these effects are via anti-oxidative by inhibiting free radicals, decreased oxidative stress, and increased antioxidant enzyme activity.

Mechanistic clues to the protective effect of chrysin against doxorubicin-induced cardiomyopathy: Plausible roles of p53, MAPK and AKT pathways

Doxorubicin (DOX) is the mainstay chemotherapeutic agent against a variety of human neoplasmas. However, its clinical utility is limited by its marked cardiotoxicity. Chrysin, is a natural flavone which possesses antioxidant, anti-inflammatory and anti-cancer properties. The current study aimed to investigate the potential protective effect of chrysin against DOX-induced chronic cardiotoxicity and the underlying molecular mechanisms. Male Sprague-Dawley rats were treated with either DOX (5 mg/kg, once a week) and/or chrysin (50 mg/kg, four times a week) for four weeks. Chrysin prevented DOX-induced cardiomyopathy which was evident by conduction abnormalities, elevated serum CKMB and LDH and histopathological changes. Chrysin also ameliorated DOX-induced oxidative stress by decreasing lipid peroxidation and upregulating the antioxidant enzymes. Moreover, chrysin attenuated DOX-induced apoptosis via decreasing expression of p53, Bax, Puma, Noxa, cytochrome c and caspase-3 while increasing expression of Bcl-2. DOX induced activation of MAPK; p38 and JNK and increased expression of NF-κB. Meanwhile, DOX suppressed AKT pathway via decreasing expression of its upstream activator VEGF and increasing expression of PTEN. Conversely, chrysin effectively neutralised all these effects. Collectively, these findings indicate that chrysin effectively protected against DOX-induced cardiomyopathy via suppressing oxidative stress, p53-dependent apoptotic pathway, MAPK and NF-κB pathways while augmenting the VEGF/AKT pathway.

Cardioprotective mechanisms of phytochemicals against doxorubicin-induced cardiotoxicity

Doxorubicin (DOX) is an anthracycline antibiotic, which is effectively used in the treatment of different malignancies, such as leukemias and lymphomas. Its most serious side effect is dose-dependent cardiotoxicity, which occurs through inducing oxidative stress apoptosis. Due to the myelosuppressive effect of dexrazoxane, a commonly-used drug to alleviate DOX-induced cardiotoxicity, researchers investigated the potential of phytochemicals for prophylaxis and treatment of this condition. Phytochemicals are plant chemicals that have protective or disease preventive properties. Preclinical trials have shown antioxidant properties for several plant extracts, such as those of Aerva lanata, Aronia melanocarpa, Astragalus polysaccharide, and Bombyx mori plants. Other plant extracts showed an ability to inhibit apoptosis, such as those of Astragalus polysaccharide, Azadirachta indica, Bombyx mori, and Allium stavium plants. Unlike synthetic agents, phytochemicals do not impair the clinical activity of DOX and they are particularly safe for long-term use. In this review, we summarized the results of preclinical trials that investigated the cardioprotective effects of phytochemicals against DOX-induced cardiotoxicity. Future human trials are required to translate these cardioprotective mechanisms into practical clinical implications.

Effects of Polyphenols on Oxidative Stress-Mediated Injury in Cardiomyocytes

Cardiovascular diseases are the main cause of mortality and morbidity in the world. Hypertension, ischemia/reperfusion, diabetes and anti-cancer drugs contribute to heart failure through oxidative and nitrosative stresses which cause cardiomyocytes nuclear and mitochondrial DNA damage, denaturation of intracellular proteins, lipid peroxidation and inflammation. Oxidative or nitrosative stress-mediated injury lead to cardiomyocytes apoptosis or necrosis. The reactive oxygen (ROS) and nitrogen species (RNS) concentration is dependent on their production and on the expression and activity of anti-oxidant enzymes. Polyphenols are a large group of natural compounds ubiquitously expressed in plants, and epidemiological studies have shown associations between a diet rich in polyphenols and the prevention of various ROS-mediated human diseases. Polyphenols reduce cardiomyocytes damage, necrosis, apoptosis, infarct size and improve cardiac function by decreasing oxidative stress-induced production of ROS or RNS. These effects are achieved by the ability of polyphenols to modulate the expression and activity of anti-oxidant enzymes and several signaling pathways involved in cells survival. This report reviews current knowledge on the potential anti-oxidative effects of polyphenols to control the cardiotoxicity induced by ROS and RNS stress.

Molecular Pathways Involved in the Amelioration of Myocardial Injury in Diabetic Rats by Kaempferol

There is growing evidence that chronic hyperglycemia leads to the formation of advanced glycation end products (AGEs) which exerts its effect via interaction with the receptor for advanced glycation end products (RAGE). AGE-RAGE activation results in oxidative stress and inflammation. It is well known that this mechanism is involved in the pathogenesis of cardiovascular disease in diabetes. Kaempferol, a dietary flavonoid, is known to possess antioxidant, anti-apoptotic, and anti-inflammatory activities. However, little is known about the effect of kaempferol on myocardial ischemia-reperfusion (IR) injury in diabetic rats. Diabetes was induced in male albino Wistar rats using streptozotocin (70 mg/kg; i.p.), and rats with glucose level >250 mg/dL were considered as diabetic. Diabetic rats were treated with vehicle (2 mL/kg; i.p.) and kaempferol (20 mg/kg; i.p.) daily for a period of 28 days and on the 28th day, ischemia was produced by one-stage ligation of the left anterior descending coronary artery for 45 min followed by reperfusion for 60 min. After completion of surgery, rats were sacrificed and the heart tissue was processed for biochemical, morphological, and molecular studies. Kaempferol pretreatment significantly reduced hyperglycemia, maintained hemodynamic function, suppressed AGE-RAGE axis activation, normalized oxidative stress, and preserved morphological alterations. In addition, there was decreased level of inflammatory markers (tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and NF-κB), inhibition of active c-Jun N-terminal kinase (JNK) and p38 proteins, and activation of Extracellular signal regulated kinase 1/2 (ERK1/2) a prosurvival kinase. Furthermore, it also attenuated apoptosis by reducing the expression of pro-apoptotic proteins (Bax and Caspase-3), Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) positive cells, and increasing the level of anti-apoptotic protein (Bcl-2). In conclusion, kaempferol attenuated myocardial ischemia-reperfusion injury in diabetic rats by reducing AGE-RAGE/ mitogen activated protein kinase (MAPK) induced oxidative stress and inflammation.

Salvianolic acid B attenuates doxorubicin-induced ER stress by inhibiting TRPC3 and TRPC6 mediated Ca2+ overload in rat cardiomyocytes

Doxorubicin (DOX)-induced cardiotoxicity is a clinically complex syndrome that leads to significant pain to cancer survivors. Endoplasmic reticulum (ER) stress has been suggested to be an important contributor to myocardium dysfunction during this phenomenon. Our previous study proved that Salvianolic acid B (Sal B) protected against doxorubicin induced cardiac dysfunction by inhibiting ER stress and cardiomyocyte apoptosis. However, the underlying molecular mechanism is not yet clearly. In this study, we investigated the protective effect and mechanisms of Sal B againest DOX-induced cardiac injury and ER stress in vivo and in vitro. After pretreatment with Sal B (0.25, 0.5, 1mg/kg i.v.) for 7 days, male SD rats were intraperitoneally injected with a single dose of DOX (3mg/kg) every 2 days for three injections. The cardioprotective effect of Sal B was observed 2 weeks after the first administration. Adult rat ventricular myocytes were isolated and treated with Sal B (20μg/ml) for 6h and then exposed in DOX (1μm) for 4h. The cardiomyocyte contractility and the level of intracellular Ca²⁺ were determined. Sal B ameliorated DOX-induced apoptosis damage in heart tissues. In vitro studies showed that DOX induced adult rat ventricular myocytes contractile dysfunction and intracellular Ca²⁺ handling derangement, disrupted mitochondrial membrane potential, raised the level of ER stress related proteins. However, Sal B pretreatment suppressed all of these adverse effects of DOX. The effects of Sal B were closely related to the inhibition of transient receptor potential canonical (TRPC) channels, as characterized by inhibiting the expression of TRPC 3 and TRPC6. These results indicate that Sal B protects against DOX-induced cardiac apoptosis and ER stress via TRPC3 and TRPC6 inhibition.

Dietary cyanidin 3-glucoside from purple corn ameliorates doxorubicin-induced cardiotoxicity in mice

BACKGROUND AND AIMS

Anthracyclines are effective anticancer drugs that have improved prognosis of hundred thousand cancer patients worldwide and are currently the most common chemotherapeutic agents used for the treatment of blood, breast, ovarian and lung cancers. However, their use is limited because of a cumulative dose-dependent and irreversible cardiotoxicity that can cause progressive cardiomyopathy and congestive heart failure. Aim of the present study was to determine the cardioprotective activity of a dietary source of cyanidin 3-glucoside (C3G), such as purple corn, against doxorubicin (DOX)-induced cardiotoxicity in mice.

METHODS AND RESULTS

In vitro studies on murine HL-1 cardiomyocytes showed that pretreatment with both pure C3G and purple corn extract improved survival upon DOX treatment. However, C3G and purple corn extract did not affect the cytotoxic effect of DOX on human cancer cell lines. We then validated in vivo the protective role of a C3G-enriched diet against DOX-induced cardiotoxicity by comparing the effect of dietary consumption of corn isogenic lines with high levels of anthocyanins (purple corn - Red diet - RD) or without anthocyanins (yellow corn - Yellow diet - YD) incorporated in standard rodent diets. Results showed that mice fed RD survived longer than mice fed YD upon injection of a toxic amount of DOX. In addition, ultrastructural analysis of hearts from mice fed RD showed reduced histopathological alterations.

CONCLUSION

Dietary intake of C3G from purple corn protects mice against DOX-induced cardiotoxicity.

Kampeferol protects against oxidative stress and apoptotic damage in experimental model of isoproterenol-induced cardiac toxicity in rats

BACKGROUND

Myocardial infarction (MI) continues to be associated with high morbidity and mortality worldwide despite the availability of current therapeutic modalities. Kaempferol (KMP), a dietary flavonoid, possesses good antioxidant, immunomodulatory and anti-apoptotic properties and has been evaluated in the present study for its role in mitigating myocardial injury following MI.

PURPOSE

In this study, the ability of KMP to protect heart against isoproterenol (ISO) induced oxidative stress and myocardial infarction was evaluated.

MATERIAL AND METHODS

Male Wistar rats (n=48) were administered KMP (5, 10 & 20mg/kg/day, i.p.) or vehicle for 15 days with ISO, 85mg/kg, subcutaneously, for 2 consecutive days was also administered at 24h interval on the 13th and 14th days. On the 15th day, rats were anaesthetized and right coronary artery was cannulated to record hemodynamic parameters. Later on blood sample was collected and heart was removed to estimate biochemical, histopathological, ultrastructural and immuohistochemical studies respectively.

RESULTS

ISO-treated rats showed a significant reduction in arterial pressure, maximum rate of development of left ventricular pressure and increase in left ventricular end-diastolic pressure. Also, there was a significant decrease in antioxidant enzyme levels such as superoxide dismutase, catalase and glutathione and increase in the level of malondialdehyde and serum TNF-α and IL-6 levels. In addition, the cardiac injury markers such as creatine kinase-MB and lactate dehydrogenase were increased in the serum. Furthermore, immunohistochemistry revealed an increased Bax/Bcl-2 ratio in the myocardium. KMP (5, 10 and 20mg/kg) dose dependently restored hemodynamic, left ventricular functions, decreased cardiac injury marker enzymes in serum, increased antioxidant levels, reduced lipid peroxidation and TNF-α level and apoptosis. Histopathological and ultrastructural studies support the protective effect of KMP in ISO-induced myocardial infarcted rats.

CONCLUSION

Thus, the present study revealed that KMP mitigates myocardial damage in ISO-induced cardiac injury by maintaining hemodynamic and biochemical parameters and reducing inflammation owing to its anti-apoptotic, anti-inflammatory and antioxidant activities. It may be concluded that a diet containing KMP may be beneficial in those who are at the risk of myocardial injury.

Myricitrin Protects against Doxorubicin-Induced Cardiotoxicity by Counteracting Oxidative Stress and Inhibiting Mitochondrial Apoptosis via ERK/P53 Pathway

Doxorubicin (Dox) is one of the most effective and widely used anthracycline antineoplastic antibiotics. Unfortunately, the use of Dox is limited by its cumulative and dose-dependent cardiac toxicity. Myricitrin, a natural flavonoid which is isolated from the ground bark of Myrica rubra, has recently been found to have a strong antioxidative effect. This study aimed to evaluate the possible protective effect of myricitrin against Dox-induced cardiotoxicity and the underlying mechanisms. An in vivo investigation in SD rats demonstrated that myricitrin significantly reduced the Dox-induced myocardial damage, as indicated by the decreases in the cardiac index, amelioration of heart pathological injuries, and decreases in the serum cardiac enzyme levels. In addition, in vitro studies showed that myricitrin effectively reduced the Dox-induced cell toxicity. Further study showed that myricitrin exerted its function by counteracting oxidative stress and increasing the activities of antioxidant enzymes. Moreover, myricitrin suppressed the myocardial apoptosis induced by Dox, as indicated by decreases in the activation of caspase-3 and the numbers of TUNEL-positive cells, maintenance of the mitochondrial membrane potential, and increase in the Bcl-2/Bax ratio. Further mechanism study revealed that myricitrin-induced suppression of myocardial apoptosis relied on the ERK/p53-mediated mitochondrial apoptosis pathway.

The Protective Role of Phenolic Compounds Against Doxorubicin-induced Cardiotoxicity: A Comprehensive Review

Although doxorubicin (DOX) is among the most widely used anticancer agents, its clinical application is hampered owing to its cardiotoxicity. Adjuvant therapy with an antioxidant has been suggested as a promising strategy to reduce DOX-induced adverse effects. In this context, many phenolic compounds have been reported to protect against DOX-induced cardiotoxicity. The cardioprotective effects of phenolic compounds are exerted via multiple mechanisms including inhibition of reactive oxygen species generation, apoptosis, NF-κB, p53, mitochondrial dysfunction, and DNA damage. In this review, we present a summary of the in vitro, in vivo, and clinical findings on the protective mechanisms of phenolic compounds against DOX-induced cardiotoxicity.

Cardioprotective Potentials of Plant-Derived Small Molecules against Doxorubicin Associated Cardiotoxicity

Doxorubicin (DOX) is a potent and widely used anthracycline antibiotic for the treatment of several malignancies. Unfortunately, the clinical utility of DOX is often restricted due to the elicitation of organ toxicity. Particularly, the increased risk for the development of dilated cardiomyopathy by DOX among the cancer survivors warrants major attention from the physicians as well as researchers to develop adjuvant agents to neutralize the noxious effects of DOX on the healthy myocardium. Despite these pitfalls, the use of traditional cytotoxic drugs continues to be the mainstay treatment for several types of cancer. Recently, phytochemicals have gained attention for their anticancer, chemopreventive, and cardioprotective activities. The ideal cardioprotective agents should not compromise the clinical efficacy of DOX and should be devoid of cumulative or irreversible toxicity on the naïve tissues. Furthermore, adjuvants possessing synergistic anticancer activity and quelling of chemoresistance would significantly enhance the clinical utility in combating DOX-induced cardiotoxicity. The present review renders an overview of cardioprotective effects of plant-derived small molecules and their purported mechanisms against DOX-induced cardiotoxicity. Phytochemicals serve as the reservoirs of pharmacophore which can be utilized as templates for developing safe and potential novel cardioprotective agents in combating DOX-induced cardiotoxicity.

Kinase analysis in alcoholic hepatitis identifies p90RSK as a potential mediator of liver fibrogenesis

OBJECTIVE

Alcoholic hepatitis (AH) is often associated with advanced fibrosis, which negatively impacts survival. We aimed at identifying kinases deregulated in livers from patients with AH and advanced fibrosis in order to discover novel molecular targets.

DESIGN

Extensive phosphoprotein analysis by reverse phase protein microarrays was performed in AH (n=12) and normal human livers (n=7). Ribosomal S6 kinase (p90RSK) hepatic expression was assessed by qPCR, Western blot and immunohistochemistry. Kaempferol was used as a selective pharmacological inhibitor of the p90RSK pathway to assess the regulation of experimentally-induced liver fibrosis and injury, using in vivo and in vitro approaches.

RESULTS

Proteomic analysis identified p90RSK as one of the most deregulated kinases in AH. Hepatic p90RSK gene and protein expression was also upregulated in livers with chronic liver disease. Immunohistochemistry studies showed increased p90RSK staining in areas of active fibrogenesis in cirrhotic livers. Therapeutic administration of kaempferol to carbon tetrachloride-treated mice resulted in decreased hepatic collagen deposition, and expression of profibrogenic and proinflammatory genes, compared to vehicle administration. In addition, kaempferol reduced the extent of hepatocellular injury and degree of apoptosis. In primary hepatic stellate cells, kaempferol and small interfering RNA decreased activation of p90RSK, which in turn regulated key profibrogenic actions. In primary hepatocytes, kaempferol attenuated proapoptotic signalling.

CONCLUSIONS

p90RSK is upregulated in patients with chronic liver disease and mediates liver fibrogenesis in vivo and in vitro. These results suggest that the p90RSK pathway could be a new therapeutic approach for liver diseases characterised by advanced fibrosis.

Protective Activity of Total Polyphenols from Genista quadriflora Munby and Teucrium polium geyrii Maire in Acetaminophen-Induced Hepatotoxicity in Rats

Oxidative stress is a major cause of drug-induced hepatic diseases and several studies have demonstrated that diet supplementation with plants rich in antioxidant compounds provides a variety of health benefits in these circumstances. Genista quadriflora Munby (Gq) and Teucrium polium geyrii Maire (Tp) are known to possess antioxidant and numerous biological properties and these endemic plants are often used for dietary or medicinal applications. Herein, we evaluated the beneficial effect of rich-polyphenol fractions of Gq and Tp to prevent Acetaminophen-induced liver injury and investigated the mechanisms involved in this protective action. Rats were orally administered polyphenolic extracts from Gq or Tp (300 mg/kg) or N-acetylcysteine (NAC: 200 mg/kg) once daily for ten days prior to the single oral administration of Acetaminophen (APAP: 1 g/kg). The results show that preventive administration of polyphenolic extracts from Gq or Tp exerts a hepatoprotective influence during APAP treatment by improving transaminases leakage and liver histology and stimulating antioxidant defenses. Besides, suppression of liver CYP2E1, GSTpi and TNF-α mRNA levels, with enhancement of mitochondrial bioenergetics may contribute to the observed hepatoprotection induced by Gq and Tp extracts. The effect of Tp extract is significantly higher (1.5–2 fold) than that of Gq extract and NAC regarding the enhancement of mitochondrial functionality. Overall, this study brings the first evidence that pretreatment with these natural extracts display in vivo protective activity against APAP hepatotoxicity through improving mitochondrial bioenergetics, oxidant status, phase I and II enzymes expression and inflammatory processes probably by virtue of their high total polyphenols content.

Kaempferol Attenuates Myocardial Ischemic Injury via Inhibition of MAPK Signaling Pathway in Experimental Model of Myocardial Ischemia-Reperfusion Injury

Kaempferol (KMP), a dietary flavonoid, has antioxidant, anti-inflammatory, and antiapoptotic effects. Hence, we investigated the effect of KMP in ischemia-reperfusion (IR) model of myocardial injury in rats. We studied male albino Wistar rats that were divided into sham, IR-control, KMP-20 + IR, and KMP 20 per se groups. KMP (20 mg/kg; i.p.) was administered daily to rats for the period of 15 days, and, on the 15th day, ischemia was produced by one-stage ligation of left anterior descending coronary artery for 45 min followed by reperfusion for 60 min. After completion of surgery, rats were sacrificed; heart was removed and processed for biochemical, morphological, and molecular studies. KMP pretreatment significantly ameliorated IR injury by maintaining cardiac function, normalizing oxidative stress, and preserving morphological alterations. Furthermore, there was a decrease in the level of inflammatory markers (TNF-α, IL-6, and NFκB), inhibition of active JNK and p38 proteins, and activation of ERK1/ERK2, a prosurvival kinase. Additionally, it also attenuated apoptosis by reducing the expression of proapoptotic proteins (Bax and Caspase-3), TUNEL positive cells, and increased level of antiapoptotic proteins (Bcl-2). In conclusion, KMP protected against IR injury by attenuating inflammation and apoptosis through the modulation of MAPK pathway.

Naringin protects against anoxia/reoxygenation-induced apoptosis in H9c2 cells via the Nrf2 signaling pathway

Naringin (Nar) is a major and active flavanone glycoside derivative of several citrus species. The antioxidant properties of Nar have an important function in its cardioprotective effects in various models. However, the effects of Nar on Nrf2 activation and the expression of its downstream genes in myocardial cells are yet to be elucidated. This study was designed to investigate the protective effects of Nar against anoxia/reoxygenation (A/R)-induced injury in H9c2 cells and determine its effects on the activity of Nrf2 and the expression of phase II antioxidant enzymes. H9c2 cells were pretreated with Nar for 6 h before exposure to A/R. A/R treatment severely injured the H9c2 cells, which was accompanied by apoptosis. Nar also suppressed the A/R-induced mitochondrial membrane depolarization and caspase-3 activation. Nar pretreatment significantly reduced the apoptotic rate by enhancing the endogenous anti-oxidative activity of superoxide dismutase, glutathione peroxidase, and catalase, thereby inhibiting intracellular reactive oxygen species generation. Moreover, the presence of Nar alone in H9c2 cells increased the nuclear translocation of Nrf2 in a dose- and time-dependent manner, as well as consistently increased the protein levels of heme oxygenase (HO-1) and glutamate cysteine ligase (GCLC). Nar increased the phosphorylation of ERK1/2, PKCδ, and AKT. However, the Nar-mediated Nrf2 activation and cardioprotection were abolished through the genetic silencing of Nrf2 by siRNA and partially inhibited by specific inhibitors of ERK1/2, PKCδ, and AKT. Therefore, Nar provided cardioprotection by inducing the phosphorylation of ERK1/2, PKCδ, and AKT, which subsequently activated Nrf2 and its downstream genes.

Assessment of Indian Rosewood (Dalbergia sissoo) Standardized Leaf Extract on Isoproterenol-Induced Myocardial Injury in Rats

The present study was undertaken to evaluate the effect of alcoholic extract of Dalbergia sissoo leaf extract (DSE) on isoproterenol (ISP)-induced myocardial injury in rats. Evaluation of three doses (30, 100 and 300 mg/kg of body weight) of DSE was done in ISP-treated rats. ISP was used at 85 mg/kg body weight by subcutaneous route for two subsequent days to induce myocardial injury in rats. Assessment of myocardial injury was done by estimation of different cardiac injury markers like LDH, CK-MB. Serum cholesterol, LDL, HDL, triglycerides in serum, myocardial infarcted area, oxidative stress and histopathology in heart tissue were also assessed in rats. Mean arterial pressure and heart rate were recorded in all the groups. Rats pretreated with DSE (30, 100 and 300 mg/kg of body weight) showed significant (p < 0.05-0.001) improvement in the heart weight/body weight ratio, myocardial infarcted areas, heart rate and mean arterial pressure in ISP-induced myocardial injury. DSE showed significant (p < 0.05-0.001) improvement in serum LDH, CK-MB, cholesterol, LDL and triglyceride levels at all the dose levels. However, DSE pretreatment had no significant effect on serum HDL level. Pretreatment with DSE (30, 100 and 300 mg/kg body weight) showed significant (p < 0.001) reduction in MDA level in comparison with myocardial injured rats. Further, antioxidant potential was also improved in terms of improved activities of reduced glutathione, superoxide dismutase and catalase with the DSE pretreatment. Histopathology also showed significant improvement in heart tissue. The study suggests that DSE showed beneficial effect in ISP-induced myocardial injury in rats.

Doxorubicin toxicity changes myocardial energy metabolism in rats

BACKGROUND

Doxorubicin (DOX) is an antitumor antibiotics used against malignancies. But its toxicity limits the therapy of DOX.

OBJECTIVE

The purpose of this study was to evaluate DOX toxicity and the alteration of energy metabolism after short term and long term treatment.

METHODS

Male Sprague-Dawley rats were randomly assigned to four groups: Short term control group, short term DOX treatment group, long term control group and long term DOX treatment group. In short term treated group, rats were injected with DOX i.p. at a dose of 2.5 mg/kg every 48 h for six equal injections. In long term, treated group, rats were tail-intravenously injected with DOX at a dose of 3 mg/kg once a week for four weeks. At the end of the experiment, histopathological changes, general blood biomarkers, endogenous antioxidant enzymes, cardiac energy metabolism and related mRNA expression of AMPK signal pathway were determined.

RESULTS

DOX induced prominent oxidative stress, a higher mortality rate, histological and ECG changes, obvious cardiac hypertrophy, acute cardiac damage and cardiac energy impairment in short term treatment rats. In long term treatment rats, DOX caused serious nephropathy and systolic dysfunction, terrible cardiac energy impairment, clear alteration of substrate utilization and AMPK signal pathway.

CONCLUSION

DOX treatment can induce different damages after short term and long term treatment. In short term treatment group, rats experienced a terrible mortality rate about 40%, the acute cardiac damage, cardiac energy impairment and an early heart failure which are potential connected with reduction of glucose utilization. In the long term treatment group, serious nephropathy and obvious changes of mRNA expressions of AMPK signal pathway were observed. Meanwhile, the serious cardiac energy impairment and substrate utilization alteration denote an obviously heart failure. This study could be helpful to develop therapy strategies of DOX complications for clinical application.