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Aim: To elucidate the mechanism responsible for the antiproliferative effects of a novel homospermidine conjugate, anthracenylmethyl homospermidine (ANTMHspd), in the human hepatoma BEL-7402 cell line. Methods: The viability of the cells was assessed by MTT assay and the trypan blue dye exclusion method. Morphological changes were observed by fluorescence microscopy with Hoechst 33258 staining. Cell cycle distribution, apoptosis, and mitochondrial membrane potential were measured by flow cytometry. Protein expression was detected by Western blot analysis. Results: ANTMHspd strongly decreased BEL-7402 cell proliferation in a dose- and time-dependent manner. Hoechst 33258 staining and the flow cytometry assay showed that ANTMHspd induced cell apoptosis and cell cycle perturbation. Furthermore, ANTMHspd could induce mitochondrial membrane potential loss and cytochrome c release and enhance cleaved caspase-3, cleaved caspase-9, and Bax protein expression without caspase-8 activation. ANTMHspd could also decrease the expression of Bcl-2 and cytochrome c in mitochondria. In addition, the specific inhibitors of caspase-9 and caspase-3 almost abolished the ANTMHspd-induced caspase-9 and caspase-3 activation, respectively. Conclusion: ANTMHspd could induce BEL-7402 cell apoptosis via the mitochondrial/caspase-dependent pathway and the Bcl-2 family was involved in the control of apoptosis. [ABSTRACT FROM AUTHOR]

Aim: To investigate the effect of clonidine, moxonidine, folic acid, and mecobalamin on arterial baroreflex (ABR) function in stroke-prone spontaneously hypertensive rats (SHR-SP) and the possible mechanisms involved. Methods: Eighty-one SHR-SP were divided into 7 groups. Four groups were designated for the intragastric (ig) administration of clonidine (1.0 and 10.0 μg/kg), moxonidine (0.1 and 1.0 mg/kg), folic acid (1.0 mg/kg), and mecobalamin (1.0 mg/kg). Three groups were for the intracerebroventricular (icv) injection of clonidine (4 μg/4 μL), moxonidine (5 μg/4 μL), and mecobalamin (20 μg/4 μL). Blood pressure (BP) was recorded in the conscious state for 30 min and baroreflex sensitivity (BRS) was determined respectively before and after drug administration. Results: Clonidine and moxonidine significantly decreased BP, prolonged the heart period (HP), and increased BRS when administered as either ig or icv injections. Both BP and HP were unchanged by ig folic acid or mecobalamin injection. However, BRS was significantly increased by both. Conclusion: Clonidine, moxonidine, folic acid, and mecobalamin improved impaired ABR function in SHR-SP. The central mechanism was involved in this effect of either clonidine or moxonidine. Mecobalamin improved ABR function through the peripheral mechanism. [ABSTRACT FROM AUTHOR]

Aim: To study the mechanisms by which N-demethyl-clarithromycin (NDC) induces human cervical cancer HeLa cell apoptosis in vitro. Methods: The viability of N-demethyl-clarithromycin-induced HeLa cells was measured by MTT assay. Apoptotic cells with condensed nuclei were visualized by phase contrast microscopy. Nucleosomal DNA fragmentation was assayed by agarose gel electrophoresis. Measurement of mitochondrial transmembrane potential was analyzed by a FACScan flowcytometer. Caspase-3, poly-(ADP-ribose) polymerase (PARP), caspase-activated DNase (ICAD), Bcl-2, Bax, p53, and SIRT1 protein expression and the release of cytochrome c were detected by Western blot analysis. Results: N-demethyl-clarithromycin, an anti-inflammatory substance, inhibited HeLa cell growth in a dose- and time-dependent manner. N-demethyl-clarithromycin induced HeLa cell death through the apoptotic pathways. The pancaspase inhibitor (z-VAD-fmk), caspase-3 inhibitor (z-DEVD-fmk) andthecaspase-9 inhibitor (z-LEHD-fmk) partially enhanced cell viability induced by N-demethyl-clarithromycin, but the caspase-8 inhibitor (z-IETD-fmk) had almost no effect. Caspase-3 was activated then followed by the degradation of caspase-3 substrates, the inhibitor of ICAD and PARP. Simultaneously, mitochondrial transmembrane potential was markedly reduced and the release of cytochrome c in the cytosol was increased. N-demethyl-clarithromycin upregulated the expression ratio of mitochondrial Bax/Bcl-2, and significantly increased the expression of the p53 protein. It also downregulated anti-apoptotic protein SIRT1 expression. Conclusion: N-demethyl-clarithromycin induced apoptosis in HeLa cells via the mitochondrial pathway. [ABSTRACT FROM AUTHOR]