Production of bioactive phenolic acids and furanocoumarins in in vitro cultures of Ruta graveolens L. and Ruta graveolens ssp. divaricata (Tenore) Gams. under different light conditions

Extracts from the biomass of Ruta graveolens and Ruta graveolens ssp. divaricata cultured in vitro under different light conditions (far-red, red and blue light, UV-A irradiation, in darkness and white light) were tested for the amounts of free phenolic acids and cinnamic acid (twelve compounds) as well as furanocoumarins and umbelliferone (seven compounds) using HPLC methods. Total amounts of the investigated groups of compounds in the cultures of both plants increased from 2.6 to 6.7 times, depending on light quality, and the maximum values reached were 106.50 and 1,276.74?mg?100?g^?1 DW (in R. graveolens), and 106.97 and 262.54?mg?100?g^?1 DW (in the subspecies), respectively. Both white light and blue light were equally beneficial for the total production of phenolic acids in cultures of both plants, whereas the total production of furanocoumarins was clearly better stimulated by blue light in R. graveolens and by darkness in the subspecies (i.e. the amounts were respectively 1.44 and 1.7 times higher than in the biomass cultivated under white light). The amounts of individual compounds in both plant cultures increased from about 2.2 to 26.3 times depending on light quality. The following bioactive compounds were obtained in quantities which are of interest from a practical perspective: in R. graveolens culture??protocatechuic acid (45?mg?100?g^?1 DW), isopimpinellin (about 500?mg?100?g^?1 DW) and bergapten (about 270?mg?100?g^?1 DW), and in the subspecies culture: p-coumaric acid (70?mg?100?g^?1 DW) and isopimpinellin (about 210?mg?100?g^?1 DW).     

Calpains mediate integrin attachment complex maintenance of adult muscle in Caenorhabditis elegans

Two components of integrin containing attachment complexes, UNC-97/PINCH and UNC-112/MIG-2/Kindlin-2, were recently identified as negative regulators of muscle protein degradation and as having decreased mRNA levels in response to spaceflight. Integrin complexes transmit force between the inside and outside of muscle cells and signal changes in muscle size in response to force and, perhaps, disuse. We therefore investigated the effects of acute decreases in expression of the genes encoding these multi-protein complexes. We find that in fully developed adult Caenorhabditis elegans muscle, RNAi against genes encoding core, and peripheral, members of these complexes induces protein degradation, myofibrillar and mitochondrial dystrophies, and a movement defect. Genetic disruption of Z-line- or M-line-specific complex members is sufficient to induce these defects. We confirmed that defects occur in temperature-sensitive mutants for two of the genes: unc-52, which encodes the extra-cellular ligand Perlecan, and unc-112, which encodes the intracellular component Kindlin-2. These results demonstrate that integrin containing attachment complexes, as a whole, are required for proper maintenance of adult muscle. These defects, and collapse of arrayed attachment complexes into ball like structures, are blocked when DIM-1 levels are reduced. Degradation is also blocked by RNAi or drugs targeting calpains, implying that disruption of integrin containing complexes results in calpain activation. In wild-type animals, either during development or in adults, RNAi against calpain genes results in integrin muscle attachment disruptions and consequent sub-cellular defects. These results demonstrate that calpains are required for proper assembly and maintenance of integrin attachment complexes. Taken together our data provide in vivo evidence that a calpain-based molecular repair mechanism exists for dealing with attachment complex disruption in adult muscle. Since C. elegans lacks satellite cells, this mechanism is intrinsic to the muscles and raises the question if such a mechanism also exists in higher metazoans.     

Neuromelanin can protect against iron-mediated oxidative damage in system modeling iron overload of brain aging and Parkinson's disease

In Parkinson's disease (PD), dopamine neurons containing neuromelanin selectively degenerate. Neuromelanin binds iron and accumulates in aging. Iron accumulates in reactive form during aging, PD, and is involved in neurodegeneration. It is not clear how the interaction of neuromelanin and iron can be protective or toxic by modulating redox processes. Here, we investigated the interaction of neuromelanin from human substantia nigra with iron in the presence of ascorbic acid, dopamine, and hydrogen peroxide. We observed that neuromelanin blocks hydroxyl radical production by Fenton's reaction, in a dose-dependent manner. Neuromelanin also inhibited the iron-mediated oxidation of ascorbic acid, thus sparing this major antioxidant molecule in brain. The protective effect of neuromelanin on ascorbate oxidation occurs even in conditions of iron overload into neuromelanin. The blockade of iron into a stable iron–neuromelanin complex prevents dopamine oxidation, inhibiting the formation of neurotoxic dopamine quinones. The above processes occur intraneuronally in aging and PD, thus showing that neuromelanin is neuroprotective. The iron–neuromelanin complex is completely decomposed by hydrogen peroxide and its degradation rate increases with the amount of iron bound to neuromelanin. This occurs in PD when extraneuronal iron–neuromelanin is phagocytosed by microglia and iron–neuromelanin degradation releases reactive/toxic iron.