Development of cost-effective strategies for environmental monitoring of irrigated areas in Mediterranean regions: Traditional and new approaches in a changing world

Methodology for measuring malonaldehyde as a product of lipid peroxidation in muscle tissues: A review

ab experiments and field survey have been carried out to investigate the impact and the relationship between the exotic crayfish; Procambarus clarkii and Schistosoma and Fasciola vector snails in Egypt. In the Lab, several species of freshwater snails, fish and aquatic plants were reported to serve as food for the freshwater crayfish. In the field, a survey for the crayfish and freshwater snails has been conducted at several irrigation channels in Qalyobiya, Ismailia and Behera governorates, which had been previously surveyed during 1990s. The results of the experimental Lab indicated that the vector snails; Biomphalaria alexandrina, Bulinus truncatus and limnaea natalensis were the preys of first choice for the crayfish. The field surveys showed high reduction and sometimes complete disappearance of vector snails in irrigation channels, which have been invaded by Procambarus clarkii, while in water courses which do not harbor the crayfish, such as El Manayef drain and Fayed canal (West of Suez Canal), high densities of these vector snails were recorded. The present study is providing encouraging indication of the possible overcoming schistosomiasis and fascioliasis in Egypt by the freshwater crayfish Procombarus clarkii.

In studies of physiological roles of lipid peroxide in cutaneous tissue, we examined serum lipid peroxide levels in 199 patients with various dermatoses such as psoriasis, eczema/prurigo, alopecia, bullous disorders, acne/seborrheic dermatitis, atopic dermatitis, SLE, urticaria, progressive systemic sclerosis, generalized morphea, and herpes zoster, by using the TBA (thiobarbituric acid) method and a new assay technique, called the MCDP (methyl carbamoyl‐dimethylamino phenothiazine)‐Hb method. The following results were obtained. By the TBA method, statistically significantly high serum lipid peroxide levels were noted in patients with psoriasis, eczema/prurigo, alopecia, SLE and generalized morphea. By the MCDP‐Hb method, similarly high levels were found in patients with alopecia and atopic dermatitis, compared with those of the control group. The discrepancy between the results from the TBA and the MCDP‐Hb methods is thought to be due to the fact that TBA method measures a secondary product of lipid peroxide, malondialdehyde, whereas the MCDP‐Hb method measures lipid hydroperoxide itself.These results suggest some involvement of lipid peroxidation in the pathogenesis or, at least, in the enhancement and modification of the symptoms in these dermatoses.

Modeling mosquitofish ( Gambusia holbrooki) responses to Genapol OXD-080, a non-ionic surfactant, in rice fields

Application of the biodegradable non-ionic surfactant Genapol OXD-080, a fatty alcohol polyglycol ester, in rice paddies has been considered as a method to mitigate damage caused by the Louisiana red swamp crayfish, Procambarus clarkii, to rice crops. The damages are a consequence of crayfish digging activities. The acute and sublethal effects of Genapol on a non-target key species were examined to assess the potential risk of contaminating the irrigation channels following its application in the rice paddies. Mosquitofish, Gambusia holbrooki, due to its abundance in irrigation channels, and because it is a predator with an intermediate position in the food chain, was selected as the key non-target species. The LC50 value for Genapol to mosquitofish was 2.9 mg l-1, a value 17.2 times lower than the Genapol concentration needed to decrease crayfish digging activity (50 mg l-1). For sublethal tests, three biological parameters were considered in laboratory experiments with mosquitofish: respiratory metabolism, food (energetic) consumption, and clutch survival. A significant decrease in the resting metabolism of mosquitofish was observed, even when Genapol exposure concentrations were very low (e.g., 0.75 mg l-1). Thus, oxygen consumption rates of mosquitofish are strongly affected by to the presence of this surfactant in water. In contrast, mosquitofish food consumption and clutch survival seemed not to be affected by sub-lethal concentrations of Genapol. Yet, sub-lethal effect concentrations for mosquitofish are so much lower than the concentration necessary to decrease significantly crayfish activity, we conclude that there is a reasonable potential risk of damaging local mosquitofish populations if contamination of the irrigation channels with Genapol occurs.

Asbestos-induced lipid peroxidation in different systems is well documented in the literature. Many reports note the detection of malondialdehyde as a measure of peroxidation of unsaturated fatty acids by the thiobarbituric acid (TBA) method. Although the TBA method is quite simple and easy to use, it has many limitations and therefore has to be cross-checked by reference to one or more other methods.

The concentration of serum lipid hydroperoxides of male rats of the Wistar strain that had received thermal injury on their backs was measured by the hemoglobin-methylene blue (Hb-MB) method. The concentration increased significantly 0.5 h after the injury, was higher than that of the normal level until 5 h, and decreased to the normal concentration by 7 h after the injury. The lipid peroxide level measured by the thiobarbituric acid (TBA) method increased up to 5 h after the injury, and then maintained at a higher level than normal for 48 h. Thus, the measurement of the total concentration of serum lipid hydroperoxides by the Hb-MB method is useful to detect lipid peroxidation in the early period after the injury, and serum lipid peroxide level measured by the TBA method may reflect the progress of systemic dysfunction.

The aim of our study was to evaluate in vitro antioxidant potential of methanolic extracts (ME) of 14 medicinal plants, 8 of which are endemic species of Anatolia. Scavenging activity was tested by 1,1-diphenyl-2-picrylhydrazyl (DPPH) method and the inhibitory effect on lipid peroxidation was examined by the ferric thiocyanate (FTC) and thiobarbituric acid (TBA) methods. The obtained results showed significant differences in the antioxidant potential amongst the tested methanolic plant extracts. Among the plant samples, Crataegus microphylla C. Koch, Salvia hypargeia Fisch. & Mey., Cotinus coggygria Scop., Origanum sipyleum L. and Rosa damascena Miller exhibited the highest DPPH scavenging activity. Five extracts (Centaurea nerimaniae Ş. Kültür, C. coggygria, Scorzonera tomentosa L., R. damascena and Colchicum sanguicolle K.M. Perss) showed strong antioxidant activity in the FTC and TBA tests, with per cent inhibition ranges of 72%–84% and 84%–92%, respectively. The ME of C. coggygria and R. damascena exhibited potent antioxidant activity by the DPPH, FTC and TBA methods.

The comparative activities of aqueous, ethanol, and methanol extracts from Aralia elata shoot (AES) and leaf (AEL) were tested by in vitro experimental models of linoleic acid peroxidation by thiocyanate and thiobarbituric acid (TBA) methods and scavenging activities of free radicals by DPPH (α,α'-diphenyl-β-picrylhydrazyl). In addition, bio-active materials (phenolic compounds and minerals) were also measured. The extract yield of each solvent extracted from AES and AEL was 3.08% and 3.13% in aqueous, 0.58% and 0.66% in ethanol, and 0.81% and 1.73% in methanol, respectively. The highest extract yield was found in the aqueous extract from AEL. Major mineral contents (㎎%) of AES and AEL were 575.7 and 759.3 in Ca, 353.5 and 330.0 in K, and 31.3 and 31.0 in Mg, respectively. The highest free radical scavenging activity was found in the aqueous extract by 28.69% at 0.1% additional level from AES and in the methanol extract by 92.36% at 0.1% additional level from AEL. Free radical scavenging activity was stronger in AEL than in AES. In antioxidative activities determined by thiocyanate and TBA methods against lipid peroxidation using linoleic acid, ethanol extracts from AEL showed the highest antioxidative activity at all treatment concentrations. These results may provide the basic data to understand the biological activities of bio-active materials derived from AES and AEL.

Oxygen free radical-mediated lipid peroxidation has been proposed to be one of the major mechanisms of secondary damage in traumatic brain injury. The first purpose of this study was to establish the time-level relationship for lipid peroxidation in injured brain tissue. The second purpose was to examine the protective effect of alpha-tocopherol against lipid peroxidation. For this study, 65 guinea pigs in five groups were studied. Five of the animals were identified as a control group, and the remaining 60 animals were divided equally into four groups (Groups A, B, C, and D). Mild injury (200 g x cm) (Groups A and C) and severe injury (1000 g x cm) (Groups B and D) were produced by the method of Feeney et al. Alpha-tocopherol (100 mg/kg) was administered intraperitoneally before brain injury in Groups C and D. Five animals from each group were killed immediately after trauma, five after 1 hour, and the remaining five animals after 36 hours. Lipid peroxidation in traumatized brain tissues was assessed using the thiobarbituric acid method. In all groups with traumatic brain injuries, levels of malondialdehyde, a lipid peroxidation product, were higher than in the control group. The amount of lipid peroxidation was increased by the severity of the trauma. Alpha-tocopherol significantly suppressed the rise in lipid peroxide levels in traumatized brain tissues. This study demonstrates that lipid peroxidation is increased by the severity of trauma and that alpha-tocopherol has a protective effect against oxygen free radical-mediated lipid peroxidation in mild and severe brain injury.

This study examines the susceptibility to lipid peroxidation of rat heart and testis microsomes, in relation to dietary vitamin A and/or E status. Four groups of rats were fed different levels of the vitamins. After a period of 8 weeks, lipid peroxide levels estimated by thiobarbituric acid method, fatty acid composition and vitamins A and E were measured in serum or in microsomes. In heart, lipid peroxide levels were enhanced in dietary vitamin E deficiency; linoleic acid 18:2 (n-6), arachidonic acid 20:4 (n-6), and docosahexaenoic acid 22:6 (n-3) were significantly decreased. In testis, dietary vitamin A deficiency significantly increased lipid peroxide production and decreased docosapentaenoic acid 22:5 (n-6) and 20:4 (n-6). Supplementation of the diet with both vitamins A and E significantly decreased lipid peroxide production but did not change the fatty acid composition. Induced lipid peroxidation increased in the heart of vitamin E-deficient rats and in the testis of vitamin A-deficient ones. Both in heart and testis, we found a good correlation between spontaneous and induced lipid peroxides and also between lipid peroxides and polyunsaturated to saturated fatty acid ratio. Besides, lipid peroxide production was well correlated with polyunsaturated fatty acids/vitamin A in testis and with polyunsaturated fatty acids/vitamin E molar ratios in heart. Membrane susceptibility to lipid peroxidation varied greatly according to dietary status and organ. Vitamin E seemed to be a more effective antioxidant for heart, and vitamin A, for testis. Supplementation enhanced the beneficial role of each vitamin.

We studied the synergistic effect of visible light and ferritin on the lipid peroxidation on a fraction of porcine photoreceptor outer segment (POS). Reaction mixtures containing the POS fraction and horse spleen ferritin were irradiated under white fluorescent light mainly at 17,000 lx or incubated under dark conditions at 37°C. The lipid peroxidation was evaluated by both the thiobarbituric acid method and the ferrous oxidation/xylenol orange method. The irradiation-induced lipid peroxidation was affected by some experimental factors such as the irradiation dose and acidity of the material. When the irradiation was stopped, the lipid peroxidation was also stopped; thereafter, the re-irradiation induced lipid peroxidation. Moreover, this lipid peroxidation was inhibited by desferrioxamine, an iron chelator, or by dimethylthiourea, a hydroxyl radical scavenger, suggesting that the lipid peroxidation involves hydroxyl radicals generated via the Fenton reaction by iron ion released from ferritin. The lipid peroxidation did not take place under dark conditions or in the absence of ferritin. This study suggested the possibility that the visible light-induced lipid peroxidation of the POS fraction in the presence of ferritin may participate in the etiology of human retinal degenerative diseases as the human retina is exposed to light for life.

Effects of glyphosate on neurotoxicity, oxidative stress and immune suppression in red swamp crayfish, Procambarus Clarkii

Intracellular lipid peroxidation was initiated by the addition of ADP-complexed ferric iron to isolated rat hepatocytes and the reaction monitored by the thiobarbituric acid method or by measurement of the formation of conjugated dienes. Both the production of malondialdehyde (thiobarbituric-acid-reacting substances) and of conjugated dienes was dependent, on the ADP-Fe-3+ concentration in a dose-related fashion. Malondialdehyde formation stopped spontaneously within 20 min after the initiation of the reaction and the plateau reached was also related to the ADP-Fe-3+ concentration. Control experiments revealed that more than 90% of the malondialdehyde accumulating during the incubation period could be ascribed to intracellular production. The cellular NADPH/NADP+ ratio was always high and only slightly decreased upon ADP-Fe-3+-induced lipid peroxidation which, however, was associated with a marked decrease in the cellular glutathione concentration. The rate of accumulation of malondialdehyde as well as the final level reached during ADP-Fe-3+-initiated lipid peroxidation was increased by the addition of chloral hydrate. This apparent stimulatory effect could, however, be ascribed to the inhibition of the mitochondrial oxidation of the malondialdehyde formed during cellular lipid peroxidation, thus allowing more malondialdehyde to accumulate during the process. ADP-Fe-3+-induced cellular lipid peroxidation was associated with a decrease in the concentration of glutathione. Also, lowering of the intracellular glutathione level by the addition of diethyl maleate or by simply preincubating the hepatocytes (up to 50 min) promoted the ADP-Fe-3+ malondialdehyde production and formation of conjugated dienes. Furthermore, when cellular glutathione concentration had been lowered by preincubation of the hepatocytes, significant malondialdehyde production could be observed even at ADP-Fe-3+ concentrations which were too low to induce measurable lipid peroxidation in fresh hepatocytes. It is thus concluded that glutathione has an important role in the cell defence against lipid peroxidation and suggested that the isolated hepatocytes provide a suitable experimental model system for the characterization of this and other possible cellular defence mechanisms and how they are affected by the nutritional status of the donor animal.

Use of seasonally flooded rice fields by fish and crayfish in a Mediterranean wetland