The effect of temperature on photosynthetic induction under fluctuating light in Chrysanthemum morifolium

The photosynthetic response was investigated on Chrysanthemum morifolium under dynamic light conditions in the 20–35 °C temperature range to evaluate the effect of climatic variables on photosynthetic induction. The plant material was grown under uniform, controlled conditions and its gas exchange was analyzed. The gas exchange measurements were used to investigate the rate of induction, momentary induction state, and the opening of stomata. At the varying temperature ranges and under dynamic light conditions, C. morifolium reached a quasi-steady-state induction equilibrium (IS_eq(PAR,T)) within 14–45 min. For the same level of photosynthetically active radiation (PAR), the equilibrated level of steady-state induction increased as the temperature increased. It was highest approximately at 30 °C. The induction state was equilibrated at a lower level as the temperature increased to 35 °C. The interaction effect of PAR and temperature on induction state was not significant. The rate of photosynthetic induction and the time required at which the induction reached its 90 % value (t ₉₀) was influenced by PAR significantly. The light history of a leaf had a significant effect on t ₉₀, indicating that the time to reach a steady-state induction is different depending on the light environment and the period at which the leaf was exposed to light. The velocity of the photosynthetic induction was not affected by the temperature. It was associated with stomatal conductance of the leaf prior to the onset of light (g _Sini).     

Chemical composition and in vitro antibacterial activity of Seseli libanotis

Summary The antibacterial efficacy of the methanol extract of the aerial parts of Seseli libanotis by using disc diffusion assay against 107 strains from 52 bacterial species and the chemical composition of the essential oil using GC/MS analysis were studied for the first time. The minimum inhibitory concentrations (MIC) of single compounds were determined by the microbroth dilution method. Gas chromatography–mass spectrophotometry analyses allowed 13 compounds to be determined; the main constituents of the essential oil of aerial parts of Seseli libanotis were trans-caryophyllene (20.39%), spathulenol (11.89%), (−)-caryophyllene oxide (11.47%), euasarone (10.66%) and delta-cadinene (9.16%). The methanol extract of Seseli libanotis had a broad-spectrum antibacterial activity (>14 mm inhibition zone in diameter) in particular against Bacillus cereus, Bacillus dipsauri, Bacillus lentimorbus, Bacillus sphaericus, Bacillus subtilis, Corynebacterium ammoniagenes, Kocuria rosea, Neisseria subflava and Micrococcus lylae. These inhibitory effects are interesting in relation to the prevention of microbial contamination in foods.     

Promising anticancer activity of a lichen,Parmelia sulcata Taylor,against breast cancer cell lines and genotoxic effect on human lymphocytes

Plants are still to be explored for new anti-cancer compounds because overall success in cancer treatment is still not satisfactory. As a new possible source for such compounds, the lichens are recently taking a great attention. We, therefore, explored both the genotoxic and anti-growth properties of lichen species Parmelia sulcata Taylor. The chemical composition of P. sulcata was analyzed with comprehensive gas chromatography–time of flight mass spectrometry. Anti-growth effect was tested in human breast cancer cell lines (MCF-7 and MDA-MB-231) by the MTT and ATP viability assays, while the genotoxic activity was studied by assays for micronucleus, chromosomal aberration and DNA fragmentation in human lymphocytes culture. Cell death modes (apoptosis/necrosis) were morphologically assessed. P. sulcata inhibited the growth in a dose-dependent manner up to a dose of 100 μg/ml and induced caspase-independent apoptosis. It also showed genotoxic activity at doses (>125 μg/ml) higher than that required for apoptosis. These results suggest that P. sulcata may induce caspase-independent apoptotic cell death at lower doses, while it may be genotoxic at relatively higher doses.     

p53 functions as a cell cycle control protein in osteosarcomas.

Mutations in the p53 gene have been associated with a wide range of human tumors, including osteosarcomas. Although it has been shown that wild-type p53 can block the ability of E1a and ras to cotransform primary rodent cells, it is poorly understood why inactivation of the p53 gene is important for tumor formation. We show that overexpression of the gene encoding wild-type p53 blocks the growth of osteosarcoma cells. The growth arrest was determined to be due to an inability of the transfected cells to progress into S phase. This suggests that the role of the p53 gene as an antioncogene may be in controlling the cell cycle in a fashion analogous to the check-point control genes in Saccharomyces cerevisiae.     

The effects of chronic smoking on lung tissue and the role of alpha lipoic acid

Abstract

We investigated the effects of alpha lipoic acid (ALA) on blood and lung tissue exposed chronically to cigarette smoke (CS). Female Sprague-Dawley rats were divided into three groups. Group 1 was the control group (CON): fresh air was supplied twice daily and 0.1 ml physiological saline was given orally for 8 weeks. Group 2 was exposed to CS: 12 cigarettes were smoked daily at two sessions for 1 h and 0.1 ml saline was given orally for 8 weeks. Group 3 (CS + ALA) was exposed to 12 cigarettes daily in two sessions for 1 h and 100 mg/kg/day ALA was given orally for 8 weeks. DNA damage was assessed using comet analysis; oxidative damage was assessed using ischemia-modified albumin (IMA) from blood; and total oxidant status (TOS), total antioxidant status (TAS) and oxidative stress index (OSI) were measured in blood and lung tissue. Histopathological and immunohistochemical evaluation of hypoxia-inducible factor (HIF)-1α, and ?2α, caspase-3, vascular endothelial growth factor (VEGF) and fibroblast growth factor (FGF₂) were conducted using lung tissue. The oxidative markers, TOS, OSI and IMA, and the comet analysis score were increased and the TAS level was decreased in the blood of the CS group compared to the CON group. IMA levels in blood, and TOS and OSI levels in the lung were decreased significantly in the CS + ALA group compared to the CS group. We observed increased septal wall thickness, marked and diffuse inflammatory reaction, emphysema, and necrotic cell debris in bronchial and bronchiolar lumens in the CS group. HIF-1α, HIF-2α, caspase-3 and FGF₂ expressions were increased, while VEGF expression decreased in the lung tissues of the CS group compared to the CON group. ALA slightly ameliorated the damage caused by chronic exposure to CS in the lungs, but further investigation is needed to determine its possible protective effects at different dosages.     

Changes in chemical compositions of substrates before and after <Emphasis Type="Italic">Ganoderma lucidum</Emphasis> cultivation

After the commercial cultivation of Ganoderma lucidum, that is becoming increasingly popular because of its valuable medicinal effects, a large amount of Ganoderma spent substrate (GSS) remains as a residual material. It is important to identify differences in the chemical compositions among GSS to indicate their suitability. This study was carried out to characterize and evaluate the substrates and GSS for the some chemical contents such as; pH, EC, organic carbon (C), total nitrogen (N), macro and micro elements and C:N ratios. The substrates were prepared by the mixtures of hornbeam and oak sawdust supplemented with wheat bran in a ratio of 20% (20WB) and tea manufacture waste in different ratios (10, 15, 20 and 25%). Organic C, C:N and pH values decreased in GSS, while N, P, K, Mg, Fe, Mn and Zn contents increased. EC and pH values of GSS varied between 1.13 and 2.33 dS m⁻¹, and 5.14 and 5.69, respectively. GSS was found rich in all investigated mineral nutrients. The highest increases in all nutrient contents were generally determined in hornbeam sawdust with 20TW spent substrate. Initial mineral composition of the wastes influenced the mineral composition of the substrates and spent substrates.     

Methionine metabolism and ultrastructural changes with D-galactosamine in isolated rat hepatocytes

The biochemical and morphological effects of 2, 10 and 100 mM of D-galactosamine (GalN) were studied in isolated rat hepatocytes during 2 h of incubation. Lactate dehydrogenase (LDH), alanine aminotransferase (ALAT) and cell viability did not change, whatever the concentration used. The variations observed, which were dose dependent, included a large drop in ATP levels and inhibition of RNA and protein synthesis. A very high concentration of GalN was necessary, however, to induce a significant decline in methionine adenosyltransferase activity compared to control cells.The use of L-[methyl-¹⁴C]methionine during cell incubation with GalN demonstrated a decrease of S-adenosyl-L-methionine (SAMe) and an accumulation of L-methionine content related to the GalN concentration. These results suggested that an hepatotoxic agent such as GalN was able to induce disturbances of methionine metabolism.Some of the ultrastructural changes observed were different from those previously found in vivo, in rats given GalN intraperitoneally, underlining the marked difference between in vivo and in vitro intoxication.     

Plasma Trace Elements, Vitamin B12, Folate, and Homocysteine Levels in Cirrhotic Patients Compared to Healthy Controls

Increased serum homocysteine (Hcy) can induce liver diseases and can play a remarkable role in hepatic disorders. The purpose of the present study therefore was to investigate the relationship between serum vitamin B(12), folate, zinc and copper, cysteine, and Hcy level differences between cirrhotic patients and healthy subjects. We studied 32 cirrhotic patients (12 females and 20 males) aged 45 +/- 11 years and 32 control subjects (12 females and 20 males) aged 39 +/- 9 years. There was an inverse correlation between Hcy and vitamin B(12) in controls (r = -0.442, p < 0.011) but not in cirrhotic patients (r = -0.147, not significant). Also, mean plasma folate was decreased in cirrhotic patients compared to controls (p < 0.001). Copper increased whereas zinc decreased significantly in cirrhotic patients. A positive correlation was seen between the Cu/Zn ratio and Cu in controls (r = 0.690, p < 0.01), but the correlation between the Cu/Zn ratio and Cu was not significant in the cirrhotic group. Negative correlations were seen between plasma concentration of zinc and the Cu/Zn ratio in controls and cirrhotic patients (r = -0.618, p < 0.01 and r = -0.670, p < 0.01, respectively). Cirrhotic patients displayed multiple abnormalities, including changes in cysteine metabolism and in zinc and copper levels. Although hyperhomocysteinemia is known as an atherogenic and thrombogenic risk factor for cardiovascular disease, it might also be a risk factor for cirrhotic patients. Plasma Hcy, vitamin B(12), and folic acid measurement may be useful in the evaluation of cirrhotic patients.