Rosmarinic acid improves oxidative stress parameters and mitochondrial respiratory chain activity following 4-aminopyridine and picrotoxin-induced seizure in mice.

Studies have indicated that epilepsy, an important neurological disease, can generate oxidative stress and mitochondrial dysfunction, among other damages to the brain. In this context, the use of antioxidant compounds could provide neuroprotection and help to reduce the damage caused by epileptic seizures and thereby the use of anticonvulsant drugs. Rosmarinic acid (RA) is an ester of caffeic acid and 3,4-dihydroxyphenylactic acid that prevents cell damage caused by free radicals, acting as an antioxidant. It also presents anti-inflammatory, antimutagenic, and antiapoptotic properties. In this work, we used two models of acute seizure, 4-aminopyridine (4-AP) and picrotoxin (PTX)-induced seizures in mice, to investigate the anticonvulsant, antioxidant, and neuroprotective profile of RA. Diazepam and valproic acid, antiepileptic drugs already used in the treatment of epilepsy, were used as positive controls. Although RA could not prevent seizures in the models used in this study, neither enhance the latency time to first seizure at the tested doses, it exhibited an antioxidant and neuroprotective effect. RA (8 and 16 mg/kg) decreased reactive oxygen species production, superoxide dismutase activity, and DNA damage, measured in hippocampus, after seizures induced by PTX and 4-AP. Catalase activity was decreased by RA only after seizures induced by 4-AP. The activity of the mitochondrial complex II was increased by RA in hippocampus samples after both seizure models. The results obtained in this study suggest that RA is able to reduce cell damage generated by the 4-AP and PTX seizures and therefore could represent a potential candidate in reducing pathophysiological processes involved in epilepsy.

Stability of reference genes for normalization of reverse transcription quantitative real-time PCR (RT-qPCR) data in bovine blastocysts produced by IVF, ICSI and SCNT.

Reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR) is a sensitive and accurate tool for quantitative estimation of gene transcription levels in preimplantation embryos. To control for possible experimental variations, gene expression data must be normalized using internal control genes commonly known as reference genes. However, the stability of reference genes can vary depending on the state of development and/or experimental conditions; hence the assessment of their stability is essential before initiating a gene expression analysis. In the present study, we used RT-qPCR to measure the transcript levels of 10 commonly used reference genes and analyzed their expression stability in bovine blastocysts produced by in vitro fertilization (IVF), intracytoplasmic sperm injection (ICSI) and somatic cell nuclear transfer (SCNT). Using the geNorm program, we found the best combination of genes to normalize gene expression data in bovine embryos at the blastocyst stage produced by IVF (HMBS, SF3A1, and HPRT1), ICSI (H2A, HMBS, and GAPDH), SCNT (ACTB, SF3A1, and SDHA) and/or between blastocysts produced by these methods (GAPDH, HMBS and EEF1A2). We also demonstrated that not only the culture conditions may affect the expression patterns in bovine blastocysts but also the choice of embryo production method may have an important effect.

Mitochondrial complex II Is essential for gametophyte development in Arabidopsis.

Mitochondrial complex II (succinate dehydrogenase [SDH]) is part of the tricarboxylic acid cycle and the respiratory electron transport chain. Its flavoprotein subunit is encoded by two nuclear genes, SDH1-1 and SDH1-2, in Arabidopsis (Arabidopsis thaliana). The SDH1-2 gene is significantly expressed only in roots, albeit at very low level, and its disruption has no effect on growth and development of homozygous mutant plants. In contrast, SDH1-1 transcripts are ubiquitously expressed, with highest expression in flowers. Disruption of the SDH1-1 gene results in alterations in gametophyte development. Indeed, heterozygous SDH1-1/sdh1-1 mutant plants showed normal vegetative growth, yet a reduced seed set. In the progeny of selfed SDH1-1/sdh1-1 plants, distorted segregation ratios were observed, and no homozygous mutant plants were obtained. Reciprocal test crosses with the wild type demonstrated that the mutated sdh1-1 allele is not transmitted through the male gametophyte and is only partially transmitted through the female gametophyte. Consistently, microscopic analysis showed that mutant microspores develop normally until the vacuolated microspore stage, but fail to undergo mitosis I, and then cell structures are degraded and cell content disappears. On the other hand, half the mutant embryo sacs showed arrested development, either at the two-nucleate stage or before polar nuclei fusion. Down-regulation of SDH1-1 by RNA interference results in pollen abortion and a reduced seed set, as in the insertional mutant. Altogether, our results show that SDH1-1, and therefore complex II, are essential for gametophyte development.