Ellagic acid as a potential antioxidant, alleviates methotrexate-induced hepatotoxicity in male rats.

BACKGROUND: Hepatotoxicity is one of the most life-threatening side-effects of Methotrexate therapy. Former studies highlighted the significance of oxidative stress in promoting Methotrexate-induced hepatotoxicity (MIH). Hence, the current study investigated the protective effect of Ellagic acid (EA), a poly-phenolic antioxidant, against MIH. METHODS: Twenty-eight male Wistar rats were grouped into four sets: group 1 (control), group 2 (injected intraperitoneally with 20 mg/kg of Methotrexate on the 9th day), group 3 (treated orally with 10 mg/kg/day of EA for 10 days and injected with Methotrexate on the 9th day) and group 4 (treated with EA for 10 days). Subsequently, biochemical and histopathological parameters were evaluated in serum samples and liver tissues. RESULTS: Methotrexate significantly increased activities of aminotransferases and ALP enzymes as well as levels of oxidative stress parameters in liver tissue. Likewise, Methotrexate decreased hepatic reduced glutathione level and activities of antioxidant enzymes. EA pre-treatment markedly attenuated the activities of aminotransferases and ALP, levels of oxidative stress parameters and augmented activities of antioxidant enzymes. Similarly, the remarkable protective effect of EA on liver has been confirmed by histological examination. CONCLUSION: In sum, the current study supports the hypothesis that EA may be used as a promising pre-therapy to prevent the MIH.

Aberrant Methylation-Mediated Suppression of APAF1 in Myelodysplastic Syndrome.

Background: Myelodysplastic syndromes (MDSs) include a diverse group of clonal bone marrow disorders characterized by ineffective hematopoiesis and pancytopenia. It was found that down regulation of APAF1, a putative tumor suppressor gene (TSG), leads to resistance to chemotherapy and disease development in some cancers. In this study, we investigated the relation of APAF1 methylation status with its expression and clinicopathological factors in myelodysplastic syndrome (MDS) patients. Materials andMethods: Methylation Sensitive-High Resolution Melting Curve Analysis (MS-HRM) was employed in studying the methylation of CpG islands in the APAF1promoter region in MDS. Gene expression was analyzed by using real time RT-PCR. Results: 42.6% of patient samples were methylated in promoter region of APAF1analyzed, while methylation of the gene was not seen in controls (P<0.05). Methylation of APAF1was significantly associated with the suppression of its mRNA expression (P=0.00). The methylation status of APAF1in advanced-stage MDS patients (80%) was significantly higher than that of the early-stage MDS patients (28.2%) (P=0.001). The difference in frequency of hypermethylatedAPAF1 gene was significant between good (37.5%) and poor (85.71%) cytogenetic risk groups (P=0.043). In addition, a higher frequency of APAF1hypermethylation was observed in higher-risk MDS group (69.2%) compared to lower-risk MDS group (34.14%) (P=0.026). Conclusion: Our study indicated that APAF1hypermethylation in MDS was associated to high-risk disease classified according to the IPSS, WHO and cytogenetic risk.

Elevation of cyclic AMP causes an imbalance between NF-kappaB and p53 in NALM-6 cells treated by doxorubicin.

We previously showed that cAMP can inhibit DNA damage-induced wild type p53 accumulation in human pre-B NALM-6 cells, leading to a profound reduction of their apoptotic response. Here, we provide evidence for the potentiation of DNA damage-induced NF-kappaB activation by cAMP. We found that inhibition of NF-kappaB activation prevents the inhibitory effect of cAMP on doxorubicin-induced apoptosis. Moreover, cAMP exerts its inhibitory effect on doxorubicin-induced apoptosis in a PKA-independent manner. The present study also shows that elevation of cAMP prolongs the phosphorylation of IkappaB and subsequent activation of NF-kappaB in doxorubicin treated NALM-6 cells in a proteasome-dependent manner. Taken together, our results demonstrate that cAMP abrogates the balance between apoptotic and antiapoptotic transcription factors that are hallmarks of DNA damage signaling.