Acta Biologica Hungarica最新文献

This study was aimed to examine the effects of seaweed extract (SW) and humic acid on the fruit yield, dry weight (DW%), protein, proline, lipid peroxidation (LPO) and antioxidative enzyme activity of pepper plants (Capsicum annuum L.) grown under saline conditions (100 mM). The obtained results indicated that salinity stress affected deleteriously plant growth and all other parameters. Besides, the treatment of seaweed (SW) and humic acid (HA) improved vegetative growth in the plant at all concentration levels applied under salinity conditions. Leaf fresh and dry weight was increased by all SW and HA applications in salinity stressed plant compared to those of control. Furthermore, there was a significant improvement in antioxidant enzyme activity, such as superoxide dismutase (SOD), peroxidase (POD), catalase (CAT) activities in the plant under salt stress and treated with SW and HA compounds. It suggests that seaweed and humic acid can enhance salt stress tolerance and leads to conservation of pepper plant against oxidative stress.

A pot experiment was performed as factorial based on randomized complete block design with three replications, to assess the effects of 1 mM spermidine (SPD) and 1 mM putrescine (PUT) on Indian mustard (Brassica Juncea L.) under different levels of watering (100, 75, 50 and 25% of field capacity). Chlorophyll a and b contents decreased, but the ratio of Chl a/b and carotenoid content increased with decreasing water supply. Foliar sprays of polyamines improved chlorophylls a and b and carotenoid contents, while the ratio of Chl a/b was reduced by these growth regulators. Relative water content, glycine betaine, proteins and soluble sugars contents were increased, but proline content was decreased by exogenous polyamines under limited water supply. Antioxidant enzyme (POX, CAT, SOD and APX) activities were enhanced by drought stress and polyamine treatments. This resulted in lower electrolyte leakage and lipid peroxidation (less MDA) under stressful conditions. The present results indicate that exogenous polyamines such as putrescine and spermidine can alleviate some of the deleterious impacts of water limitation on Indian mustard.

The objectives of this study were to isolate, purify and determine host range of lytic bacteriophages infecting foodborne the pathogen Salmonella Typhimurium and S. Enteritidis. River/stream water, sewage, raw foods, wastewater from food processing plants, slaughterhouse and fish farms and water from troughs were used for the screening of bacteriophages. The richest sources in terms of phages infecting S. Typhimurium and Enteritidis were found to be sewage, wastewaters of slaughterhouse, food processing and fisheries and streams. A total of 33 S. Typhimurium and 56 S. Enteritidis phages were isolated and purified from the samples. It was demostrated that host ranges of the isolated phages were quite wide. The numbers of bacteria types inhibited by S. Typhimurium or Enteritidis phages were changed among 1-15 and 1-19, respectively. It was found that 75.8% (25 out of 33) and 83.93% (47 out of 56) of isolated S. Typhimurium or Enteritidis phages formed clear plaques and were capable of lysing at least six or two Salmonella serovars. Beside Salmonella serovars, some S. Typhimurium (15 out of 33, 45.5%) and S. Enteritidis phages (5 out of 56, 8.93%) were also infective against E. coli strains. The host ranges of S. Typhimurium phages were wider than those of S. Enteritidis.

Hatching is an important phase of the development of pulmonate gastropods followed by the adult-like extracapsular foraging life. Right before hatching the juveniles start to display a rhythmic radula movement, executed by the buccal complex, consisting of the buccal musculature (mass) and a pair of the buccal ganglia. In order to have a detailed insight into this process, we investigated the serotonergic regulation of the buccal (feeding) rhythm in 100% stage embryos of the pond snail, Lymnaea stagnalis, applying quantitative immunohistochemistry combined with the pharmacological manipulation of the serotonin (5-HT) synthesis, by either stimulating (by the 5-HT precursor 5-hydroxytryptophan, 5-HTP) or inhibiting (by the 5-HT synthesis blocker para-chlorophenylalanine, pCPA) it. Corresponding to the direction of the drug effect, significant changes of the fluorescence intensity could be detected both in the cerebral ganglia and the buccal complex. HPLC-MS assay demonstrated that 5-HTP increased meanwhile pCPA decreased the 5-HT content both of the central ganglia and the buccal complex. As to the feeding activity, 5-HTP induced only a slight (20%) increase, whereas the pCPA resulted in a 20% decrease of the radula protrusion frequency. Inhibition of 5-HT re-uptake by clomipramine reduced the frequency by 75%. The results prove the role of both central and peripheral 5-HTergic processes in the regulation of feeding activity. Application of specific receptor agonists and antagonists revealed that activation of a 5-HT1-like receptor depressed the feeding activity, meanwhile activation of a 5-HT6,7-like receptor enhanced it. Saturation binding plot of [3H]-5-HT to receptor and binding experiments performed on membrane pellets prepared from the buccal mass indicated the presence of a 5-HT6-like receptor positively coupled to cAMP. The results suggest that 5-HT influences the buccal (feeding) rhythmic activity in two ways: an inhibitory action is probably exerted via 5-HT1-like receptors, while an excitatory action is realized through 5-HT_6,7-like receptors.

There is an evident relationship between the fertilizing capacity of sperm and the normal morphology, quality chromatin, and motility of sperm. It is well known that thyroid hormones are the important regulators of testicular function. A correlation was found between the hypothyroidism and sperm damages. The present study was conducted to investigate the effects of hypothyroidism on sperm morphology, chromatin quality, and motility. For this purpose, 20 male mice were divided into the control and the hypothyroid groups that received 0.05% 6-n-propyl-2-thiouracil (PTU) for 35 days. Sperm morphology with Papanicolaou staining and sperm chromatin quality with both Aniline Blue (AB) and Toluidine blue (TB) staining were assessed. Besides, immunohistochemistry and real-time PCR were performed to evaluate the changes of cation sperm channel (CatSper) genes. A significant increase in the sperm chromatin condensation was found in the hypothyroid mice compared to the control mice (p < 0.05). Furthermore, a significant decrease was observed in the morphology of normal sperm in hypothyroid mice compared to the controls (p < 0.05). The results showed that Hypothyroidism could downregulate the expression of CatSper genes. Immunohistochemical data confirmed the real time-PCR results. Furthermore, the results showed that hypothyroidism could adversely affect sperm morphology, sperm chromatin condensation, and CatSper gene expression in mice and these abnormalities may be related to the excessive production of reactive oxygen species (ROS) in a hypothyroid state.

Seeds of snail medic (Medicago scutellata L.) were assessed for their response to salt at the germination and seedling stages. NaCl at concentrations 86 and 170 mM decreased the final germination percentage. Embryonic axis length, water content and dry weight of embryonic axis and cotyledons were also reduced by salt treatment. Furthermore, 28-d-old plants were grown hydroponically with different NaCl concentrations (0, 86 and 170 mM). After 7 days of treatment, growth, water content and development of the different organs of M. scutellata plant were affected especially at the highest NaCl concentration (170 mM). However, NaCl did not affect root length and the number of stem shoots but reduced stem length and total leaf area. Salt treatment increased markedly the concentration of Na⁺ in leaf and root tissues while reduced that of K⁺ only in root and stem tissues. Lipid peroxidation revealed the damage of the membranes of roots and leaves. Moreover, showed a more intense suberization and lignification at the cambial zone of roots of M. scutellata, were observed under the effect of NaCl.

In this study, we analyzed extracts of Ribes (black currant, red currant and gooseberry) fruits obtained with methanol, methanol 50% and water. For each extract total polyphenol content, total flavonoid content and total anthocyanin content was assessed. The antioxidant activity of extracts was evaluated by 1,1-Diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical scavenging capacity and by the photo-chemiluminescence (PCL) method. Identification and quantification of individual phenolic compounds was performed by means of high performance liquid chromatograph coupled with diode array detector (HPLC-DAD) analyses. From each fruit, best extraction of polyphenols was obtained with methanol 50%. In case of red currants and gooseberry there was no significant difference in flavonoids and anthocyanins extraction rate by the different extraction solvents. For black currants the methanol and methanol 50% extract presented the highest antioxidant activity. For red currants extracts with methanol 50% showed stronger antioxidant activity (IC₅₀ = 5.71 mg/ml for DPPH, IC₅₀ = 1.17 mg/ml for ABTS) than those with methanol or water. In case of gooseberry by the DPPH test the water extract proved to be the most active (IC₅₀ = 5.9 mg/ml). In the PCL test black currants methanol 50% extract was over 6 times more powerful as the ones from red currants. In case of gooseberries, water extract presented the highest antioxidant activity (41.84 μmol AAE/g). In black currant cyanidin-3-glucoside was the major compound. Quercetin 3-O-glucoside was identified in each sample. From cinnamic acid derivatives neochlorogenic acid was present in black currants in the highest amount (356.33 μg/g).

The protective role of arbuscular mycorrhizal fungi (AMF) against the phytopathogen Clavibacter michiganensis subsp. michiganensis (Cmm) was examined in tomato plants. Seven different AMF isolates were used to determine which ones were able to induce effectively resistance against Cmm. Stems of seven-week tomato plants were infected with Cmm, then a disease severity index (DSI) was determined during the next three weeks. In addition to different responses to mycorrhizal inoculation, three levels of responses to the bacterial disease were recognized in treatments. Plants inoculated with Rhizophagus irregularis (Ri) showed both the highest colonization and the highest induced resistance to Cmm while the effect of Funneliformis mosseae, Gigaspora margarita and Claroideoglomus claroideum on mycorrhizal colonization and on the induced resistance were intermediate and high, respectively. Subsequently, Ri was chosen to inoculate ethylene-insensitive tomato mutant line Never ripe (Nr) and its background (Pearson) to investigate the possible role of ethylene (ET) in the mycorrhiza-induced resistance (MIR). The results showed that Ri could induce systemic resistance against Cmm in the Pearson background, whereas ET-insensitivity in Nr plants impaired MIR. These results suggest that ET is required for Ri-induced resistance against Cmm. To our knowledge, this is the first study to examine the effect of different AMF isolates on the response of tomato plants to Cmm and involvement of ET in MIR against Cmm.

Aqueous extract of the spines of the brown bullhead catfish (Ameiurus nebulosus Lesueur, 1819) caused contraction of the guinea-pig small intestine in vitro, a widely-used preparation in pharmacology. The action is dependent on extracellular Ca²⁺, and probably takes place on the smooth muscle cells. Mouse gastrointestinal preparations were also contracted by the extract. Stings by the spines of this fish species causes a painful sensation in man. We tested the effect of an extract of spines in isolated organ experiments on innervated smooth muscle preparations. In the guinea-pig ileum, the response to the extract was abolished by the Ca²⁺-channel blocker nifedipine, but only slightly reduced by atropine (a muscarine receptor antagonist) or tetrodotoxin (TTX; a blocker axonal conduction) or antagonists for P_2X purinoceptors. Blocking of serotonin or histamine H₁ receptors, tachykinin NK₁ receptors, functional impairment of capsaicin-sensitive sensory nerve endings or inhibition of cyclo-oxygenases failed to influence the contractile effect of the extract. No inhibitory action of the extract was detected on the ileum subject to electrical motor nerve stimulation.

The objective of this study was to identify the bioactive compounds of essential oil and evaluate the antibacterial activity of the essential oil extracted from Chenopodium album subsp. striatum against multidrug-resistant bacterial strains (MDR) which were isolated from clinical specimens by conventional methods. Furthermore, eight different Gram-negative and Gram-positive multidrug-resistant bacterial strains were used to investigate the antibacterial potential of the essential oil. The antibacterial activity was tested using MIC and MBC microdilution method, well and disc diffusion in different concentration. The hydro-distillation of aerial parts powder yield was 0.466% (v/w). Essential oil showed bactericidal activity against both MDR Gram-negative and Gram-positive bacterial strains. MIC and MBC results were ranged from 0.31 to 2.5 and 0.62 to 5.0 mg/mL. The inhibition zones in well-diffusion method were ranged from 7 ± 0.6 mm to 15 ± 1.0 mm. Disc diffusion method was ranged from 7 ± 0.0 mm to 16 ± 0.6 mm depending on the type of bacteria strain and essential oil concentration. Essential oil of Ch. album had the greatest potential to be considered as an antibacterial agent against MDR bacteria strain. This potential was due to different biological and bioactive compounds like phytol, linalool, α-terpineol and linolenic acid in the plant.