Search

Hesperetin (HSP) is a natural flavonoid that offers useful curative effects for cardiovascular diseases, but its effect on myocardial ischemia and its precise mechanism remains unclear. The aim of this study is to explore the potential cardioprotective mechanism of HSP on myocardial ischemia caused by isoproterenol (ISO). Adult male Kunming mice were randomly divided into five groups: control, ISO, low-dose HSP (L-HSP, 25 mg/kg/d), high-dose HSP (H-HSP, 50 mg/kg/d), and verapamil (VER) group. Treatment groups of mice received HSP or VER for seven days, and the groups other than the control group were injected with ISO (100 mg/kg/d) subcutaneously for two consecutive days to establish a model of myocardial ischemia. Electrocardiogram and heart-histology changes were used to assess changes in myocardial architecture. The activities and the content of oxidative stress markers and inflammatory cytokines were determined and assayed using kits respectively. The expressions of proteins associated with apoptosis and the Sirt1/Nrf2 pathway were evaluated by Western blotting. The results demonstrate that VER, L-HSP and H-HSP significantly reduced the J-point displacement, heart rate, cardiac pathomorphological changes, and the levels of creatine kinase, lactated dehydrogenase, malonaldehyde, interleukin-6, and tumor necrosis factor-α in serum while promoting the activation of superoxide dismutase, catalase, glutathione in serum in the ISO-treated animals. Furthermore, L-HSP and H-HSP also reversed the ISO-induced apoptosis and the changes in the Sirt1/Nrf2 signaling pathway, as evident from the levels of proteins Bax, Bcl-2, caspase-3, Sirt1, Nrf2, NQO-1, and HO-1. In conclusion, HSP plays a protective role in ISO-induced myocardial ischemia by modulating oxidative stress, inflammation, and apoptosis via Sirt1/Nrf2 pathway activation. [Display omitted] • Hesperetin attenuates oxidative stress, inflammation, and apoptosis in mouse heart. • Hesperetin activates the expression of the Sirt1/Nrf2 pathway. • Hesperetin has a protective action on isoproterenol-induced myocardial ischemia. [ABSTRACT FROM AUTHOR]

• Crocetin attenuates oxidative stress, inflammation and apoptosis in the kidney. • Crocetin activates the expression of the PI3K/AKT pathway related genes. • Crocetin has a protective action on arsenic trioxide-induced nephrotoxicity. Arsenic trioxide (ATO)-induced renal toxicity through oxidative stress and apoptosis restricts the therapeutic action of acute myelogenous leukemia. Crocetin (Crt) possesses antioxidant and antiapoptosis properties, and has certain renal protective effects, but it has not been reported that it has protective effect on renal injury caused by ATO. The current study explored the effects and mechanisms of Crt on kidney damage induced by ATO. Fifty Sprague-Dawley rats were randomly divided into five groups. Adult rats were given Crt concurrently with ATO for 1 week. On the 8th day, rats were killed and blood and kidney tissues were collected. Histopathological changes were measured, and kidney tissues and serum were used to determine renal function and antioxidant enzyme activity. In addition, the protein expression levels of P-PI3K, PI3K, P-AKT, AKT, CytC, Bax, Bcl-2 and Caspase-3 were determined via western blot analysis. Results revealed ATO induced renal morphological alterations and activated serum BUN and CRE. Compared with the control group, ROS, MDA, IL-1β, TNF-α, protein carbonyls (PC), lipid hydroperoxides (LOOH) and arsenic concentration levels were found to be significantly increased and SOD, CAT, GSH-Px, GSH and total sulphydryl groups (TSH) levels were attenuated in the ATO group. Crt markedly reduced oxidative stress in ATO-induced nephrotoxicity. Further, ATO induced apoptosis by significantly enhancing CytC, Bax and Caspase-3 and inhibiting Bcl-2. Administration with Crt markedly improved the expression of apoptosis factor. Moreover, Crt treatment stimulated the expressions of P-PI3K, PI3K, P-AKT, AKT induced by ATO. This study indicates Crt could prevent renal injury caused by ATO through inhibiting oxidative stress, inflammation and apoptosis, and its mechanism may be related to activation of PI3K/Akt signaling pathway. [ABSTRACT FROM AUTHOR]

Acute myeloid leukemia (AML) is a hematological malignancy with rapid disease progression and often becomes lethal without treatment. Development of effective new therapies is essential to improve the clinical outcome of AML patients. Enhancer of zeste homolog 2 (EZH2) and lysine specific demethylase 1 (LSD1) play important roles in epigenetic regulation and their altered expressions have been observed in cancer. Although EZH2 and LSD1 have opposite histone methylation functions, we found that both enzymes were paradoxically up-regulated in AML cells. Importantly, a combined inhibition of EZH2 and LSD1 resulted in a synergistic activity against AML in vitro and in vivo. Such synergy was mechanistically correlated with up-regulation of H3K4me1/2 and H3K9Ac and down-regulation of H3K27me3, leading to a decrease of anti-apoptotic protein Bcl-2. These epigenetic alterations also compromised the mitochondrial respiration capacity and glycolytic activity and resulted in ATP depletion, a key event contributing to the potent cytotoxic effect of the drug combination. Taken together, our work identified a novel therapeutic approach against AML by combining two small molecules that inhibit different histone methylation-modulating proteins with apparently opposite enzyme activities. Such a new drug combination strategy likely has significant clinical implications since epigenetic modulators are currently in clinical trials. [ABSTRACT FROM AUTHOR]