Caspase Inhibitors and Myocardial Apoptosis

Geraniol Ameliorates Doxorubicin-Mediated Kidney Injury through Alteration of Antioxidant Status, Inflammation, and Apoptosis: Potential Roles of NF-κB and Nrf2/Ho-1

Doxorubicin-mediated kidney impairment is a serious problem in cancer treatment. Accordingly, this work investigated the ability of geraniol to modulate doxorubicin-induced kidney damage using a rat model. Rats were randomly assigned to four groups: control, doxorubicin (20 mg/kg, intraperitoneal, i.p.), doxorubicin plus 100 mg/kg of geraniol, and doxorubicin plus 200 mg/kg of geraniol. A single doxorubicin injection triggered kidney impairment, as evidenced by the altered serum creatinine, blood urea nitrogen, and albumin values; it also caused histological changes in the kidney architecture. Additionally, doxorubicin enhanced lipid peroxidation while lowering reduced glutathione, catalase activity, and the expression of glutathione peroxidase and superoxide dismutase. Interestingly, pre-treatment with geraniol rescued doxorubicin-induced alterations in kidney antioxidant parameters, enzymatic activity, and the expression of inflammatory and apoptosis-mediating gene and proteins. Moreover, prophylactic treatment with geraniol preserved most kidney histological characteristics in a dose-dependent manner. These findings support that geraniol could protect against doxorubicin-mediated kidney dysfunction. However, further research is needed to clarify the mechanisms of geraniol’s protective effects against doxorubicin-mediated kidney dysfunction.

Protective effect of diosmin against doxorubicin-induced nephrotoxicity

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Dox induces kidney damage.

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Dox leads to a decrease in antioxidant defense mechanism.

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Diosmin administration restores antioxidant properties.

Doxorubicin (Dox) is an anthracycline antibiotic that is primarily used for treating various solid tumors including that of pulmonary, ovary, breast, uterine, cervix, and several blood cancers. However, nephrotoxicity associated with Dox treatment limits its clinical use. Administration of Dox in combination with compounds exhibiting antioxidant properties are being used to minimize the side effects of Dox. Diosmin is a flavonoid glycoside with numerous beneficial properties that is found in the pericarp of many citrus fruits. Diosmin has demonstrated antioxidant, anti-inflammatory, and anti-apoptotic effects in response to various insults, although the exact mechanism remains unknown. Therefore, this study was designed to evaluate the effect of diosmin in preventing kidney damage in response to Dox treatment. Male Wistar rats were randomly divided into four groups: control group, Dox group (20 mg/kg, i.p.), Dox plus low-dose diosmin group (100 mg/kg orally), and Dox plus high-dose diosmin group (200 mg/kg orally). A single intraperitoneal injection of Dox resulted in kidney damage as evidenced by significant alterations in kidney markers, histological abnormalities, and the attenuation of antioxidant defense mechanisms (GSH, SOD, and CAT). Moreover, Dox treatment significantly altered the expression of oxidative stress, inflammatory, and anti-apoptotic protein markers. Diosmin pretreatment alleviated Dox-induced nephrotoxicity by ameliorating the antioxidant mechanism, decreasing inflammation and apoptosis, and restoring kidney architecture. In conclusion, our results indicate that diosmin is a promising therapeutic agent for the prevention of nephrotoxicity associated with DOX.

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.

A computational and functional study elicits the ameliorating effect of the Chinese herbal formula Huo Luo Xiao Ling Dan on experimental ischemia-induced myocardial injury in rats via inhibition of apoptosis

Ischemic heart disease (IHD) is the leading cause of death worldwide and remains a major life-threatening factor in humans. Apoptosis has been implicated in the pathogenesis of IHD. The Chinese herbal formula Huo Luo Xiao Ling Dan (HLXLD), one of the commonly used Chinese herbal formulas, consists of Salviae miltiorrhizae, Angelica sinensis, Gummi olibanum, and Commiphora myrrha, with a wide spectrum of pharmacological activity. However, the mechanism of action and molecular targets of HLXLD in the treatment of IHD are unclear. This study aimed to computationally predict the molecular interactions between the major active components of HLXLD and key regulators of apoptosis and then examine the effect of HLXLD on coronary artery ligation-induced acute myocardial ischemia in rats. The molecular interactions between the major active components of HLXLD, including ferulic acid, ligustilide, succinic acid, vanillic acid, tanshinone IIA, tanshinone IIB, danshensu, salvianolic acid A, salvianolic acid C, protocatechuic aldehyde, and β-boswellic acid and human protein molecules including B cell lymphoma-extra large (Bcl-xl), B cell lymphoma 2 antagonist/killer 1 (Bak1), B cell lymphoma 2 (Bcl-2), procaspase 3, and caspase 9 with regard to hydrogen bond formation, charge interaction, and π-π stacking using Discovery Studio(®) program 3.1. The 12 HLXLD components were predicted by ADMET (absorption, distribution, metabolism, excretion and toxicity) Predictor to have favorable pharmacokinetic and low hepatotoxicity profiles. The acute myocardial ischemia was established by surgical ligation of the left anterior descending coronary artery. The rats were divided into a sham operative group, a model group, a positive control group treated with 0.2 mg/kg isosorbide mononitrate, and groups treated with 2.7, 5.4, or 10.8 g/kg HLXLD. The results showed that administration of HLXLD increased mean arterial pressure, left ventricular systolic pressure, heart rate, and maximal rate of rise/descent of left ventricular pressure levels. Administration of HLXLD significantly ameliorated coronary artery ligation-induced tissue damage in the left ventricle, with restored arrangement of myocardial fibers and recovered myoplasm in rats. Furthermore, HLXLD markedly increased the expression level of Bcl-2 but decreased the level of cleaved caspase 3. Taken together, administration of HLXLD attenuated acute myocardial ischemia-induced damage in cardiomyocytes and inhibited apoptotic death of cardiomyocytes, thereby exerting a cardioprotective effect in rats with IHD. These findings suggest that HLXLD may represent a promising herbal formula for the treatment of cardiovascular disease by counteracting apoptotic cell death via multiple active compounds. More studies are warranted to fully elucidate the mechanisms of action, identify the therapeutic targets, and validate the efficacy and safety of HLXLD in the treatment of IHD.

Low-intensity ultrasound and microbubbles enhance the antitumor effect of cisplatin

Cell permeabilization using microbubbles (MB) and low-intensity ultrasound (US) have the potential for delivering molecules into the cytoplasm. The collapsing MB and cavitation bubbles created by this collapse generate impulsive pressures that cause transient membrane permeability, allowing exogenous molecules to enter the cells. To evaluate this methodology in vitro and in vivo, we investigated the effects of low-intensity 1-MHz pulsed US and MB combined with cis-diamminedichloroplatinum (II) (CDDP) on two cell lines (Colon 26 murine colon carcinoma and EMT6 murine mammary carcinoma) in vitro and in vivo on severe combined immunodeficient mice inoculated with HT29-luc human colon carcinoma. To investigate in vitro the efficiency of molecular delivery by the US and MB method, calcein molecules with a molecular weight in the same range as that of CDDP were used as fluorescent markers. Fluorescence measurement revealed that approximately 10(6)-10(7) calcein molecules per cell were internalized. US-MB-mediated delivery of CDDP in Colon 26 and EMT6 cells increased cytotoxicity in a dose-dependent manner and induced apoptosis (nuclear condensation and fragmentation, and increase in caspase-3 activity). In vivo experiments with xenografts (HT29-luc) revealed a very significant reduction in tumor volume in mice treated with CDDP + US + MB compared with those in the US + CDDP groups for two different concentrations of CDDP. This finding suggests that the US-MB method combined with chemotherapy has clinical potential in cancer therapy.

Apoptosis in hypertensive heart disease: a clinical approach

PURPOSE OF REVIEW

It is widely accepted that there are two principal forms of cell death, namely, necrosis and apoptosis. According to the classical view, necrosis is the major mechanism of cardiomyocyte death in cardiac diseases.

RECENT DEVELOPMENTS

In the past few years observations have been made showing that cardiomyocyte apoptosis occurs in diverse conditions including hypertensive heart disease, and that apoptosis may be a contributing cause of loss and functional abnormalities of cardiomyocytes in this condition.

SUMMARY

This review will summarize recent evidence demonstrating the potential contribution of cardiomyocyte apoptosis to heart failure in hypertensive patients. In addition, some strategies aimed to detect and prevent apoptosis of cardiomyocytes will be considered.

Cardiovascular effects of the thiazolidinediones

Thiazolidinediones, used for the treatment of diabetes mellitus type 2, modulate gene expression by binding to nuclear transcription factor, peroxisome proliferator-activated receptor-gamma. Peroxisome proliferator-activated receptor-gamma is expressed in several tissues, therefore, thiazolidinediones have biological effects on multiple organ systems. Here, we describe evidence that thiazolidinediones have beneficial effects on the cardiovascular system independent of their antidiabetic effect. Studies in animals have clearly shown that thiazolidinediones decrease blood pressure, left ventricular hypertrophy, development of atherosclerotic lesions, and protect myocardium from ischemia/reperfusion injury. Although relatively few studies in humans have been reported, the preponderance of available evidence suggests a beneficial effect of thiazolidinediones. Thus, by modulating gene expression, thiazolidinediones may provide a novel method for the prevention and treatment of cardiovascular diseases.