The modulation of SIRT1 and SIRT3 by natural compounds as a therapeutic target in doxorubicin-induced cardiotoxicity: A review.

Doxorubicin (DOX) is a potent antitumor agent with a broad spectrum of activity; however, irreversible cardiotoxicity resulting from DOX treatment is a major issue that limits its therapeutic use. Sirtuins (SIRTs) play an essential role in several physiological and pathological processes including oxidative stress, apoptosis, and inflammation. It has been reported that SIRT1 and SIRT3 can act as a protective molecular against DOX-induced myocardial injury through targeting numerous signaling pathways. Several natural compounds (NCs), such as resveratrol, sesamin, and berberine, with antioxidative, anti-inflammation, and antiapoptotic effects were evaluated for their potential to suppress the cardiotoxicity induced by DOX via targeting SIRT1 and SIRT3. Numerous NCs exerted their therapeutic effects on DOX-mediated cardiac damage via targeting different signaling pathways, including SIRT1/LKB1/AMPK, SIRT1/PGC-1α, SIRT1/NLRP3, and SIRT3/FoxO. SIRT3 also ameliorates cardiotoxicity by enhancing mitochondrial fusion.

Cardioprotective Activities of Ethanolic Extract Root of Ageratum conyzoides on Alloxan-Induced Cardiotoxicity in Diabetic Rats.

Diabetes mellitus has developed into one of the debilitating diseases disturbing the health of many people living with cardiovascular diseases in modern times. The root of Ageratum conyzoides was investigated for its effects on alloxan-induced diabetic Wistar rats' cardiac tissues. Thirty-two (32) Wistar rats weighing between 180 and 190 g were randomly divided into four groups. The animals in groups B-D were induced with a single dose of 150 mg/kg body weight of alloxan (ALX) intraperitoneally. They were confirmed hyperglycemic after 72 hours of induction and then sustained in hyperglycemic condition for 2 weeks. Animals in groups C and D received AC intervention, as stated above, for four weeks. The body weight of the experimental animals and blood collection for glucose estimation were taken weekly for six weeks using appropriate instruments. Biochemical assays for lipid profile, antioxidant enzymatic, and nonenzymatic markers were carried out. Histopathological changes in the cardiac tissues were also studied. Administration of 150 mg/kg of ALX to experimental rats induced diabetes and significantly reduced the body weights, significantly (p < 0.05) increased the glucose level, triglyceride (TG), total cholesterol (TC), and low-density lipoprotein (LDL) levels, and decreased the levels of high-density lipoprotein (HDL) and antioxidant enzymatic markers such as catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx) while the antioxidant nonenzymatic marker such as malondialdehyde (MDA) level was significantly increased. By contrast, rats given the ethanolic extract root of A. conyzoides had significantly (p < 0.05) increased the body weight gain, whereas the glucose levels significantly (p < 0.05) improved in treated diabetic rats. This extract also improved the cardiovascular system of the diabetic rats by significantly decreasing TG and LDL levels, significantly (p < 0.05) increasing the HDL level, significantly reducing the cardiac contents of CAT, SOD, and GPx, and significantly (p < 0.05) decreasing MDA. Ethanolic extract root of A. conyzoides exhibited antihyperglycemic and antihyperlipidemic activities and mitigates damage to the heart from the ALX-induced myocardial toxicity associated with type-1 diabetes.

Folic acid reduces doxorubicin-induced cardiomyopathy by modulating endothelial nitric oxide synthase.

The use of doxorubicin (DOXO) as a chemotherapeutic drug has been hampered by cardiotoxicity leading to cardiomyopathy and heart failure. Folic acid (FA) is a modulator of endothelial nitric oxide (NO) synthase (eNOS), which in turn is an important player in diseases associated with NO insufficiency or NOS dysregulation, such as pressure overload and myocardial infarction. However, the role of FA in DOXO-induced cardiomyopathy is poorly understood. The aim of this study was to test the hypothesis that FA prevents DOXO-induced cardiomyopathy by modulating eNOS and mitochondrial structure and function. Male C57BL/6 mice were randomized to a single dose of DOXO (20 mg/kg intraperitoneal) or sham. FA supplementation (10 mg/day per oral) was started 7 days before DOXO injection and continued thereafter. DOXO resulted in 70% mortality after 10 days, with the surviving mice demonstrating a 30% reduction in stroke volume compared with sham groups. Pre-treatment with FA reduced mortality to 45% and improved stroke volume (both P < 0.05 versus DOXO). These effects of FA were underlain by blunting of DOXO-induced cardiomyocyte atrophy, apoptosis, interstitial fibrosis and impairment of mitochondrial function. Mechanistically, pre-treatment with FA prevented DOXO-induced increases in superoxide anion production by reducing the eNOS monomer:dimer ratio and eNOS S-glutathionylation, and attenuated DOXO-induced decreases in superoxide dismutase, eNOS phosphorylation and NO production. Enhancing eNOS function by restoring its coupling and subsequently reducing oxidative stress with FA may be a novel therapeutic approach to attenuate DOXO-induced cardiomyopathy.