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AIMS: To investigate the antioxidant activities and effects of free phenols (FPPB) and bound phenols (BPPB) of Parkia biglobosa leaves on some enzymes of neuro-cardiovascular relevance. METHODS AND RESULTS: HPLC-DAD fingerprinting of FPPB and BPPB, and the antihemolytic, radical (1,1-diphenyl-2 picrylhydrazyl, DPPH; 2,2-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid), ABTS) scavenging and ferric reducing antioxidant properties of extracts, were assessed. In addition, the effects of the phenolics on angiotensin-1-converting enzyme (ACE), cerebral acetylcholinesterase/butyrylcholinesterase (AChE/BuChE), and Na+/K+ATPase were determined in vitro. FPPB was more potent than BPPB in terms of ABTS (EC50:4.06 ± 0.3 vs 24.07 ± 2.1 µg/mL) and DPPH (EC50:3.82 ± 0.2 vs 10.22 ± 0.1 µg/mL) radicals scavenged, respectively. The free phenolic extract was a better DPPH. scavenger than ascorbic acid (EC50 = 12.58 ± 0.4 µg/mL; DPPH reference) and compared well with Trolox (EC50:4.44 ± 0.08 µg/mL; ABTS reference). The anti-hemolytic effect of FPPB (36%) and BPPB (53%) was highest at 15 µg/mL but lower than that recorded for ascorbic acid (67% at 10 µg/mL). Even though FPPB (IC50 = 15.35 ± 4.0 µg/mL) and BPPB (IC50 = 46.85 ± 3.3 µg/mL) showed considerably lower ACE-inhibitory effect than ramipril (IC50:0.173 ± 0.04 µg/mL), both extracts demonstrated dose-dependent, significant (p < 0.01/p < 0.05) inhibition of the enzyme. FPPB increased cerebral Na+/K+ATPase activity but neither phenolic extract affects cerebral AChE/BuChE activities. HPLC-DAD revealed catechin, caffeic acid, and quercetin, respectively, as the major phenolics (mg/g) in FPPB (29.85, 30.29, and 17.10) and BPPB (32.70, 30.51, and 19.25). CONCLUSION: The effects of P biglobosa on ACE and cerebral ATPase are related to its constituent phenolics. ACE inhibition could be an important mechanism underlying the documented hypotensive effect of the plant.

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OBJECTIVE: Methanolic leaf extracts of Parkia biglobosa, PBE, and one of its major polyphenolic constituents, catechin, were investigated for their protective effects against neurotoxicity induced by different agents on rat brain hippocampal slices and isolated mitochondria. METHODS: Hippocampal slices were preincubated with PBE (25, 50, 100, or 200 µg/mL) or catechin (1, 5, or 10 µg/mL) for 30 min followed by further incubation with 300 µM H2O2, 300 µM SNP, or 200 µM PbCl2 for 1 h. Effects of PBE and catechin on SNP- or CaCl2-induced brain mitochondrial ROS formation and mitochondrial membrane potential (ΔΨm) were also determined. RESULTS: PBE and catechin decreased basal ROS generation in slices and blunted the prooxidant effects of neurotoxicants on membrane lipid peroxidation and nonprotein thiol contents. PBE rescued hippocampal cellular viability from SNP damage and caused a significant boost in hippocampus Na(+), K(+)-ATPase activity but with no effect on the acetylcholinesterase activity. Both PBE and catechin also mitigated SNP- or CaCl2-dependent mitochondrial ROS generation. Measurement by safranine fluorescence however showed that the mild depolarization of the ΔΨm by PBE was independent of catechin. CONCLUSION: The results suggest that the neuroprotective effect of PBE is dependent on its constituent antioxidants and mild mitochondrial depolarization propensity.

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Leachate from a municipal battery recycling site is a potent source of mixed-metal released into the environment. The present study investigated the degree at which mixed-metal exposure to the municipal auto-battery leachate (MABL) and to the Elewi Odo municipal auto-battery recycling site leachate (EOMABRL) affected the lipid membrane of the testes in in vitro experiment. The results showed elevated level of mixed-metals over the permissible levels in drinking water, as recommended by regulatory authorities. In the leachate samples, the levels of malondialdehyde (MDA), a biomarker of lipid damage, was significantly (p<0.05) increased in rat testes in a dose-dependent manner. MDA induced by the municipal auto-battery leachate (MABL) was significantly (p<0.05) higher than the leachate from Elewi Odo municipal auto-battery recycling site (EOMABRL). The testicular lipid membrane capacity was compromised following treatment with leachate from the municipal battery recycling site, implicating mixed-metal exposure as the causative agent of testicular damage and male infertility.

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hnRNP proteins are involved in many cell functions, primarily in pre-mRNA processing. We report here a comparative analysis of the genes of the 2xRBD members of the hnRNP family and of their expression products. Starting from the seven well characterized hnRNP members of human and murine origin (A0, A1, A2/B1, A3, AB, D and DL) and the three MuSashI-like proteins with related RBD tandems (MSI1, MSI2 and DAZAP1), we identified through BLAST search 12 homologous genes in the genome of Danio rerio and 10 in the genome of Takifugu rubripes, which can be divided into three subgroups, each with its highly conserved exon/intron structure, matching perfectly the exon/intron structures found in human and mouse genes. An exception is the gene of hnRNP A0, which is intronless consistently in all the four species. The analysis has been supported also at the level of cDNA and EST databases and extended in this respect to other vertebrate species, namely chicken, Xenopus laevis and Silurana tropicalis. PHYLIP 3.62 package (SEQBOOT, PROTDIST/DNADIST, NEIGHBOR, CONSENSE) was used for all the proteins and their CDSs and human RBDs I and II to infer relevant aspects of the phylogenesis of these proteins. Some clues to the evolution of introns in these genes have come from the analysis of their distribution in homologous genes of other eukaryotes, namely Ciona, Drosophila, Caenorhabditis, Saccharomyces and Arabidopsis.

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