Miriam Rindner

The combined influence of temperature and modified atmospheres on Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae)

Abstract In laboratory experiments, egg, larval, pupal, and adult stages of the red flour beetle Tribolium castaneum (Herbst) were exposed to three low oxygen concentrations realistically obtainable under hermetic storage conditions, at three temperatures of 26, 30, and 35 °C. The gas concentrations were: 1% O2, 85% N2, 14% CO2; 2% O2, 84.7% N2, 13.3% CO2; 3% O2, 85% N2, 12% CO2 (all at 75% relative humidity). When exposed to the 3% O2 level at 26 °C, adults were most tolerant with a mortality of 70.5% when exposed for 10 d. To obtain 99% mortality at 35 °C with the atmosphere containing 1% O2, a maximum of only 44 h was required for the most tolerant stage, namely the pupa. Comparison of exposure times required to produce 50% kill (LT50) showed that the effect of temperature on mortality rates was pronounced at all three levels of O2; for all the insect stages, values of LT50 at 35 °C ranged between 0.16 and 0.5 times those at 26 °C. The insects were also submitted to a gas mixture containing 1% O2 in 99% N2 representing a mixture obtainable by N2 flushing techniques. At the higher temperatures, differences in mortality from those obtained on exposure to 1% O2:85% N2:14% CO2 were not significant. However, at 26 °C, mortality levels of insects exposed to this mixture were lower, particularly for adults and eggs.

Protective Effects of the Essential Oil of Salvia fruticosa and Its Constituents on Astrocytic Susceptibility to Hydrogen Peroxide-Induced Cell Death

Oxidative stress has been implicated in pathologic processes associated with neurodegenerative diseases. Astrocytes, the most abundant glial cell type in the brain, protect neurons from reactive oxygen species (ROS), and any damage to them will affect neuronal survival. This study compares the ability of essential oils prepared from different herbs and spices to protect cultured primary brain astrocytes from H2O2-induced death. The results show that the essential oil of Salvia fruticosa (Sf) among the tested essential oils demonstrated remarkable protective activity. The protective effect of Sf could be attributed to alpha-humulene and alpha-pinene. Following incubation, alpha-humulene and trans-beta-caryophyllene could be found in the cytosol of astrocytes. It is proposed that Sf, by attenuating H2O2-induced cell death, might be used as a functional food or may be offered as a means of therapy in the treatment of neurodegenerative diseases.

Low Temperature as an Alternative to Fumigation for Disinfecting Dried Fruit from Three Insect Species

Abstract The effect of exposure to 0, −5, −10 and −18 °C was investigated on all developmental stages of the stored product insects Tribolium castaneum (Herbst), Oryzaephilus surinamenisis (L.), and Ephestia cautella (Walker). For all three species the estimated time to produce 99% kill of the least sensitive stage of the least sensitive species ranged from 625 h for pupae of E. cautella at 0 °C, 55 h for pupae of E. cautella at −5 °C, 6.1 h for eggs of E. cautella at −10 °C, to 2.6 h for eggs of E. cautella at −18 °C. Interspecific comparisons of mortalities were made at the LT50 level, due to the wide confidence limits at high mortalities especially at the lower temperatures. For T. castaneum the adult was least sensitive at 0 and −5 °C and the pupa at −10 and −18 °C. For E. cautella the least sensitive stage at 0 and −5 °C was the pupa, and at −10 and −18 °C the egg. For O. surinamensis the least sensitive stage at 0 °C was the larva, at −5 and −18 °C the adult, and at −10 °C the pupa.

The influence of different treatments causing emigration of nitidulid beetles

Experiments were carried out to investigate the influence of different modified atmospheres, low pressures alone, methyl bromide (MB) alone, and MB in combination with CO2 or low pressure, in causing nitidulid beetles to emigrate from infested dried fruit for which dates served as a model. All the treatments at 4 h and 16 h exposure and at 26°C, had a marked influence in causing insects to abandon the infested fruit. The most effective treatments at the two exposures were pressures of 50 mm Hg, and 1.4% O2 in air, both of which caused over 87% of the initial insect populations to emigrate from the fruit. At 4 h exposure, 2.8% O2 was less effective than 100 mm Hg or MB. At 16 h exposure, MB+CO2 was third in effectiveness and 100 mm Hg was one of the least effective treatments.

Use of Heat for Disinfestation and Control of Insects in Dates: Laboratory and Field Trials

Heat treatment of dates at the time of harvest, was examined as an alternative to fumigation with methyl bromide, which has been phased out in Israel under the Montreal Protocol. In laboratory studies, the influence of 40°, 45°, 50° and 55°C on the levels of disinfestation and mortality ofCarpophilus hemipterus larvae was examined over a 2-h exposure period. The ratio of the number of insects found outside the feeding sites to the total number of insects, was greatest at 50°C (92.3%), significantly greater than at 40° and 55°C. At 50° and 55°C, 100% mortality was obtained. Since drying temperatures for most date varieties is between 45° and 50°C, and because percent disinfestation and control was most effective at 50°C, these findings were examined under field conditions. Field trials were carried out at a commercial drying station where the crated dates are placed on the ground inside a plastic-clad hothouse. The stacks were covered with plastic liners to form ‘drying ducts’ through which heated air was sucked using fans positioned at the opposite end of the ducts. It was shown that from 1 to 2 h were required for the dates to reach the set temperature of 50°C. During the following 2-h aeration, the dates were exposed to 50°C heated air, after which an examination of infested dates inserted into the drying ducts, and natural infestations showed that successful control and emigration were obtained. This method produced results comparable to those obtained with methyl bromide fumigation, and was suitable as a replacement technology for infestation control.

Protective and Antioxidant Effects of a Chalconoid from Pulicaria incisa on Brain Astrocytes

Oxidative stress is involved in the pathogenesis of neurodegenerative diseases such as Parkinsons and Alzheimers diseases. Astrocytes, the most abundant glial cells in the brain, protect neurons from reactive oxygen species (ROS) and provide them with trophic support, such as glial-derived neurotrophic factor (GDNF). Thus, any damage to astrocytes will affect neuronal survival. In the present study, by activity-guided fractionation, we have purified from the desert plant Pulicaria incisa two protective compounds and determined their structures by spectroscopic methods. The compounds were found to be new chalcones—pulichalconoid B and pulichalconoid C. This is the first study to characterize the antioxidant and protective effects of these compounds in any biological system. Using primary cultures of astrocytes, we have found that pulichalconoid B attenuated the accumulation of ROS following treatment of these cells with hydrogen peroxide by 89% and prevented 89% of the H2O2-induced death of astrocytes. Pulichalconoid B exhibited an antioxidant effect both in vitro and in the cellular antioxidant assay in astrocytes and microglial cells. Pulichalconoid B also caused a fourfold increase in GDNF transcription in these cells. Thus, this chalcone deserves further studies in order to evaluate if beneficial therapeutic effect exists.

Propylene oxide: A potential quarantine and pre-shipment fumigant for disinfestation of nuts

Propylene oxide (PPO) was evaluated at a low pressure of 100 mm Hg for toxicity to different life stages of the Indianmeal mothPlodia interpunctella (Hübner) in the presence and absence of three species of nuts. Eggs and larvae were generally the most tolerant life stages in empty chambers and on the nut crops. Complete mortality of all life stages was achieved at a concentration x time (CT) product of 61.2 mg hl−1 for empty space fumigation. Dosages of 13.9, 60.3, 72.1 and 93.1 mgl−1 were required to kill 99% of the larvae when fumigation of 4-h duration took place in an empty chamber and in the presence of peanuts, almonds and walnuts, respectively. After an initial dose of 68.7 mgl−1 and a 5-h exposure time, sorption of PPO by peanuts, almonds and walnuts was relatively high, ranging from 87% of the initial concentration for peanuts to 91% for walnuts. PPO residues measured in peanuts, almonds and walnuts were 111, 46 and 80 ppm, respectively, 1 day after termination of fumigation. All of these values were below the 300 ppm maximum tolerance set by the FDA of the United States. These data show that the combination of PPO and low pressure has the potential to replace methyl bromide fumigation for quarantine and pre-shipment purposes.

The influence of low temperatures on two species of Carpophilus (Col., Nitidulidae)1

The effect of exposure to 0 °C., −5 °C., −10 °C and −18 °C was investigated on all developmental stages of Carpophilus hemipterus L. and C. mutilatus Er.

Downregulation of Microglial Activation by Achillolide A

Chronic inflammation has been implicated in the pathogenesis of various neurodegenerative diseases. During the neuroinflammatory process, microglial cells release neurotoxic and proinflammatory mediators. In the present study, using activity-guided fractionation, we have purified an anti-inflammatory compound determined by spectroscopic methods to be a sesquiterpene lactone named achillolide A from Achillea fragrantissima (Forsk.) Sch. Bip. In primary cultures of lipopolysaccharide-activated microglial cells, achillolide A inhibited the lipopolysaccharide-induced levels of proinflammatory and toxic mediators including glutamate, nitric oxide, matrix metalloproteinase-9, cyclooxygenase-2, induced nitric oxide synthase, interleukin-1β, and tumor necrosis factor-α. Achillolide A also exhibited an antioxidant capacity, as was shown in a cell free system as well as by its ability to reduce intracellular reactive oxygen species levels in microglial cells. Thus, achillolide A might have therapeutic potential for treatment of neurodegenerative diseases and deserves further studies.

Extract of Achillea fragrantissima Downregulates ROS Production and Protects Astrocytes from Oxidative-Stress-Induced Cell Death

Anat Elmann1, Alona Telerman1, Sharon Mordechay1, Hilla Erlank1, Miriam Rindner1, Rivka Ofir2 and Elie Beit-Yannai3 1Department of Food Science, Volcani Center, Agricultural Research Organization, Bet Dagan, 2Dead Sea & Arava Science Center and Department of Microbiology & Immunology Ben-Gurion University of the Negev, Beer-Sheva, 3Department of Clinical Pharmacology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel