Effects Of Sublethal Concentrations Research Articles

Larvicidal activity of extracts from Ammi visnaga Linn. (Apiaceae) seeds against Culex quinquefasciatus Say. (Diptera: Culicidae)

Efficacies of the Ammi visnaga seeds extract and a majority of substances on larval Culex quinquefasciatus mortality in various development stages including pupae were studied. The effect of exposure time on larval mortality was also studied. The effect of sublethal concentrations or short exposure times on further larval development and subsequent fecundity in adults were studied as well.Lethal doses of the extract were estimated for the 2nd, 3rd and 4th instar of C. quinquefasciatus (LC50 for 18, 23 and 180 mg L−1, respectively). The majority of furanochromenes, khellin and visnagin, were identified by analysing the extract. Khellin was significantly more effective compared to visnagin, whose LC50 was estimated at 8, 10 and 41 mg L−1 for the 2nd, 3rd and 4th instar larvae. Khellin showed very fast efficacy on mortality for the 3rd instar larvae in a concentration of 100 mg L−1. Fifty percent mortality was determined 30 min after application, a time which was considerably shorter compared to the extract (113 min) or visnagin (169 min). The effect of the application of lethal concentrations on C. quinquefasciatus larval mortality was studied. The least number of adults were hatched after application of the extract and khellin (41.8% and 37.9%, respectively), less than after visnagin application (46.7%) or in the control (94.2%). LC50 application caused lower fecundity in the hatched adults, lower hatchability of the eggs, and also very low natality, more than 77% lower for khellin compared to the control.A short exposure, corresponding to our estimated LT30, caused no significant acute toxicity in the larvae (until 24 h) for the extract or visnagin (4.3% and 11.5%, respectively); however, 18 min of action from khellin caused a 54.3% mortality rate of the larvae within 24 h.

Sublethal effects of Biomite® on the population growth and life table parameters of Tetranychus turkestani Ugarov and Nikolskii on three cucumber cultivars

Abstract The strawberry spider mite Tetranychus turkestani Ugarov & Nikolskii (Prostigmata: Tetranychidae) is an important pest on greenhouse cucumber. Therefore, understanding the effect of sublethal concentration of acaricides using demographic toxicological analysis is important for successful management of this pest. Laboratory studies were conducted to assess sublethal (LC25) effects of Biomite®, a natural based miticide, on the population growth and life-table parameters of T. turkestani. Three commonly greenhouse cucumber cultivars including Milad, Khasib and Puia were used in the study. Developmental times of T. turkestani immature stages were decreased on treated cultivars, while total life spans were significantly increased on treated cultivars when compared with the control groups. For Milad cultivar, adult pre-oviposition period (APOP) was significantly decreased when females were treated with LC25 of Biomite®. However, the total pre-oviposition period (TPOP) increased in the treated females. ...

In Chaotropy Lies Opportunity.

In Chaotropy Lies Opportunity.

Effects of Sublethal Concentrations of Water-Soluble Fraction of Petroleum on the Innate Immune System of Marine Fish Rachycentron Canadum (Linnaeus, 1766)

Effects of Sublethal Concentrations of Water-Soluble Fraction of Petroleum on the Innate Immune System of Marine Fish Rachycentron Canadum (Linnaeus, 1766) Petroleum is a natural product derived from the decomposition of organic matter. With increasing exploration, production and transportation of petroleum, the spill accident occurrence in the marine environment has become routine. After the shedding occur various physical, chemical and biological processes that result in the water-soluble fraction formation of petroleum, rich in hydrocarbon, molecules that are toxic to fish. Thus, the objective of this study was to evaluate the effects of sublethal concentration of 0.3 ppm of the petroleum WSF in the innate immune system parameters of Rachycentron canadum, after the periods of 7 and 14 days. It was used after the normality test, statistical analysis ANOVA followed by Tukey HSD (significant difference: p<0.05). The differential leukocyte count showed an increased number of total leukocytes after 7 days and decreased after 14 days of exposure. Consequently, there is a decrease in the number of erythrocytes in 7 days and an increase after 14 days. The activity of the lysozyme enzyme in animals of group exposed for 14 days was higher compared to the animals of control group. There were, also, changes in gill and kidney tissues after morphometric and histological analysis in animals exposed to WSF of petroleum for 7 and 14 days. It was concluded that the sublethal concentration of 0.3 ppm of the WSF of petroleum alters parameters of the innate immune system of Rachycentron canadum that may cause immunosuppression. This study allows more efficient environmental monitoring on the Brazilian coast.

Variations in Hepatosomatic Index (HSI) and Gonadosomatic Index (GSI) in Fish Heteropneustes fossilis Exposed to Higher Sub-Lethal Concentration to Arsenic and Copper

The effect of sub lethal concentration 1.31 ppm and 1.84 ppm for Arsenic and Copper on the Hepatosomatic and Gonadosomatic indices of the fish Heteropneustes fossilis was studied. In mature female catfish Heteropneustes fossilis on exposure to both test metals at both higher sub lethal concentration registered marked toxicological alterations and reduction in Hepatosomatic index (HSI) and Gonadosomatic index (GSI) throughout the year in exposed fish group. However in the control group fish the values of HSI and GSI in the increasing order in relation to seasonal variation to their maximum range during pre-spawning phase. The reduced values of above parameter found directly proportional to the metal concentration and duration of the exposure. The results of the present study will be useful for selective breeding programme, conservation and sustainable fishery management of H. fossilis in its natural habitat.

Effect of sub lethal concentration of imidacloprid on proximate body composition of Labeo rohita

Randomly selected 320 fingerling of Labeo rohita were collected from Faheem fish farm, Mattital Road, Multan. Groups of 40 fish each were exposed to subleathal concentration of imidacloprid (120 mg L-1) under short (2, 4 and 8 days) and long term (16, 32 and 64 days) conditions to access the effect of this most extensively used pesticide on the body composition parameters of economically most important fresh water fish, L. rohita, in Pakistan. Separate control groups were used for each imidacloprid treatment. It was found that most of the studied body composition parameters remained unaffected during short and long term experimental treatments as compared to their respective control groups with the exception of the 64 days treatment where several parameters including body weight (p = 0.02), dry body weight (p = 0.005), % dry weight (p = 0.001), total water contents (p = 0.04), total fat (p = 0.03), % fat wet weight (p = 0.001), % fat dry weight (p = 0.003), total organic contents (p = 0.04), % organic content wet weight (p = 0.001), total proteins (P p = 0.005) and % protein wet body weight (p = 0.001) had significantly lower values in imidacloprid treated fish as compared to control group. Our results indicated that chronic exposure of imidacloprid can adversely affect the nutritional quality of L. rohita.

Immunotoxicity in ascidians: Antifouling compounds alternative to organotins—IV. The case of zinc pyrithione

New biocides such as the organometallic compound zinc pyrithione (ZnP) have been massively introduced by many countries in formulations of antifouling paints following the ban on tributyltin (TBT). The effects of sublethal concentrations (LC50=82.5μM, i.e., 26.2mg/l) on cultured haemocytes of the ascidian Botryllus schlosseri have been investigated and compared with TBT. The percentage of haemocytes with amoeboid morphology and containing phagocytised yeast cells were significantly (p<0.05) reduced after exposure to 0.1 (31.7μg/l) and 0.5μM (158μg/l), respectively. An antagonistic interaction in inducing cytoskeletal alterations was observed when ZnP and TBT were co-present in the exposure medium. ZnP affected only the actin component. As caused by TBT, ZnP induced apoptosis and inhibited both oxidative phosphorylation and lysosomal activities. In contrast to the case of TBT, a decrement in Ca2+-ATPase activity and a decrease in cytosolic Ca2+ were detected after incubation at the highest concentration (1μM, i.e., 317.7μg/l) used. In comparison with other antifouling compounds, ZnP shows as much toxicity as TBT to cultured haemocytes at extremely low concentrations interfering with fundamental cell activities.

Cytotoxicity of benalaxyl, metalaxyl, and triadimefon on Chinese hamster ovary cells

The cytotoxicity of the fungicides benalaxyl, metalaxyl, and triadimefon was evaluated in vitro using the Chinese hamster ovary (CHO-K1) cell line. The midpoint cytotoxicity values of neutral red (NR) incorporation (NRI50), total cellular protein content (TCP50), and the methyl tetrazolium assay (MTT50) were estimated. Benalaxyl was the most cytotoxic fungicide, followed by metalaxyl and triadimefon. Fetal calf serum (10%) caused a reduction in benalaxyl, metalaxyl, and triadimefon cytotoxicity by factors of 1.8, 1.3, and 1.3. The effects of sublethal concentrations (NRI25) of the three fungicides on the glutathione redox cycle components glutathione S-transferase, glutathione reductase, glutathione peroxidase, and total glutathione content were studied. The ameliorative effects of extracellular glutathione (1 mmol L−1), vitamin C (70 µmol L−1), and vitamin E (30 µmol L−1) were also investigated. The three antioxidants led to significant effects on the glutathione redox cycle components.

Research note: The Effect of &lt;i&gt;Moringa oleifera&lt;/i&gt; Leaf Dust on Selected Biochemical Parameters of Hybrid Catfish

The study was conducted to ascertain the effect of sub-lethal concentrations (0.00, 0.04, 0.08, 0.12 and 0.16mg/L) of Moringa oleifera leaf dust after the 21-day experimental period on selected biochemical parameters of hybrid catfish (Clarias gariepinus X Heterobranchus bidorsalis) with mean length (28.39 ± 0.33cm) and weight (99.34 ± 2.48g). The experiment was conducted using static renewable bioassay system with triplicate experimental set-up. At the end of the experimental period, the blood, liver and kidney were obtained from the sacrificed fish. These tissue/organs were prepared for the selected biochemical parameters (uric acid, inorganic phosphorus, calcium, creatinine, urea, bilirubin, potassium and chloride) using standard procedures. These parameters were assayed using the standardized procedures of available commercial reagent kits. There were no significantly (p&gt;0.05) difference in the tissue/organs mean inorganic phosphorus, urea, bilirubin and potassium. However, calcium level were significantly different (p&lt;0.05) in fish exposed to the highest concentration of Moringa oleifera leaf dust. The kidney uric acid was showed significant difference fish exposed to 0.12 and 0.16mg/L Moringa oleifera leaf dust. in kidney uric acid compared to the control fish. The result suggested that the effect of Moringa oleifera leaf dust was mild at the exposed concentrations where concentrations of 0.12 and 0.16mg/L revealed highest changes observed.Keywords: Health status, Fish, Medicinal plant

Biochemical Parameters of Common Carp ( Cyprinus carpio ) Exposed to Crude Leaf Extract of Cannabis Sativa

The effect of sub-lethal concentrations (1.88, 3.75, 7.50, 15.00 and 30.00 mg/L) of crude leaf extract of Cannabis sativa was determined in the plasma, liver and gill biochemical parameters of Common carp, Cyprinus carpio (mean weight of 15.05±0.05g) after 56-day exposure period in static renewable bioassay system. During the experiment, some physicochemical parameters were monitored while at the end of the experiment, the selected biochemical parameters were determined in the plasma, liver and gill of the test fish. The biochemical parameters determined were alkaline phosphatase (ALP), Lactate dehydrogenase (LDH), total protein (TP), aspartate aminotransferase (AST), alanine aminotransferase (ALT), bilirubin, total bilirubin (TB), albumin (ALB), urea acid (UA) and cholesterol (CHOL). The monitored pH showed significant difference (p 0.05) in C. sativa test set-ups compared to the control during the experimental period. There were significant difference (p<0.05) in some of the determined biochemical parameters of the test fish exposed to C. sativa compared to the control. Therefore, it can be deduce from the study that prolonged exposure of C. carpio fingerlings to crude leaf extract of C. sativa affected some determined biochemical parameters in the tissue/organs of the test fish.

Effect of deltamethrin on some aspects of lipid metabolism in fresh water fish Labeo rohita (hamilton).

Effect of sub lethal concentration of deltamethrin (0.01µg/lt) was studied on total lipids, lipase activity and free fatty acids of the fish Labeo rohita . The levels of total lipids declined on 1 st day exposure and gradually elevated on 7 th day and 15 th day. From 15 th day onwards their levels gradually declined and came nearer to control at 30 th day exposure period. In contrast to this the levels of lipase activity and free fatty acids followed an opposite tend.

Haematological Responses, Serum Biochemistry and Histology of Clarias gariepinus (Burchell, 1822) Exposed to Sublethal Concentrations of Cold Water Fresh root Bark Extracts of Plumbago zeylanica (Leadwort)

The effect of sub lethal concentrations of fresh root bark extracts of Plumbago zeylanica on blood compositions of Clarias gariepinus was investigated under static water renewal bioassay during a 21-day exposure period. Concentrations of Plumbago zeylanica extracts used were 0 (control), 26, 39 and 59 mgl-1. The exposure led to anaemic response in fish, this was observed to be time and dose dependent. There were significant decreases in haematological values of PCV (20.66 ± 2.84), Haemoglobin (6.73 ± 0.87), RBC (1.70 ± 0.02), MCV (32.67 ± 0.33), MCHC (38.67 ± 4.33), and MCH (119.67 ± 14.84) at 59 mgl-1. While slight increase was observed in WBC (16016.67 ± 1717. 63) at 39 mgl-1. The muscle/flesh of the exposed fish showed goblet cell hyperplasia, muscle necrosis and calcification at lower concentrations of exposure for both the short term and long term exposure, but disappears at higher concentrations after one week withdrawal without bioaccumulation in the Organs and Tissues. The changes observed indicates that haematological indices could be used as risk assessment tools in aquatic environmental monitoring to assess physiological status of fish exposed to sub lethal effect of toxicants.

Lethal and Sublethal Effects of Salinity on Three Common Texas Amphibians

Amphibian populations worldwide are experiencing declines and contaminants are hypothesized to be one of the leading contributors to these declines. In particular, the salinization of amphibian habitats is a global issue that has received relatively little attention. Of the recent studies that have emerged, the majority focus on single-species responses, and because these studies often vary in methodology, assessing tolerances across species can be challenging. Thus, one step toward a broader understanding of salt loading is to assess tolerances across multiple species using similar methodologies. Additionally, in nature, amphibians can face low, sublethal concentrations of increased salinity. Though not lethal, these low concentrations can have long-term impacts on amphibian traits such as mass or their responses to future stressors. To address these issues, we first compared relative salinity tolerances of three common frogs in central Texas (Incilius nebulifer, Gulf Coast Toad; Lithobates berlandieri, Rio Grande Leopard Frog; and Acris crepitans, Blanchard's Cricket Frogs). Next, we explored the effect of sublethal salinities on the mass of I. nebulifer. Finally, we investigated the potential for sublethal salinities to increase tolerance of I. nebulifer to a later exposure of lethal salinity concentrations (acclimation). We found that across the three amphibian species, A. crepitans tadpoles were the most tolerant, followed by L. berlandieri tadpoles, and then I. nebulifer tadpoles. Sublethal concentrations of salinity did not affect mass of I. nebulifer tadpoles. Finally, exposure to sublethal levels of salinity did not increase tolerance of I. nebulifer tadpoles to a later exposure of higher salinity concentrations. Instead, tadpoles exposed to sublethal concentrations of salinity died at a faster rate when exposed later to a higher salinity concentration. With the increasing potential for salt loading to amphibian habitats due to anthropogenic influences and global climate change, understanding the consequences of salinity across multiple species as well as the effects of sublethal concentrations has important implications for amphibian conservation.

Effect of Sub Lethal Concentration of Malathion on Metabolic Profiles and Histological Studies in Heart Tissue of Channa Punctatus

Pesticides have an innate capacity to cause damage to biological system. Considering above fact the present study deals with the effect of the insecticide malathion on histological and biochemical study on cardiac muscle tissue in Channa punctatus. In present study effect of sub lethal concentration (0.8 ppm) of malathion on protein, lipid and glycogen content and histopathological changes in heart tissue of fresh water fish Channa punctatus during 96 hours was studied. Structural variations like congestion, atrophy were observed in cardiac muscle of Channa puncctatus during 96 hours sub lethal treatment of malathion. Total protein, lipid and glycogen showed decrement in cardiac muscle of Channa punctatus Keywords: Malathion, sub lethal, cardiac muscle, Channa punctatus.

Effects of Lead and Zinc on The Proximate Composition of Post Juvenile Clarias Gariepinus

Effects of sub lethal concentrations of lead and zinc salts (Pb(NO3)2 and ZnCl2) on the proximate composition and energy content of the flesh of post juvenile Clarias gariepinus was investigated in this study. All proximate compo-nents (amino acids, protein, and lipid) and total energy content, except carbohydrate showed a consistent reduction in de-tected levels as compared to values recorded at day 0 in exposed fishes and their controls. Physiological response of organ-isms was also indicated to be affected by other environmental stressors during the experiment apart from the investigated metal salts.

TOXIC EFFECT OF AQUEOUS EXTRACT OF GARLIC ON PROTEIN CONTENT IN FISH CHANNA PUNCTATUS

In the present investigation, the effect of sub lethal concentration of the garlic aqueous extract on fish Channa punctatus were studied after 24 hrs, 48 hrs, 72 hrs and 96 hrs exposure respectively. Different concentrations of garlic (10 ppm/lit, 15 ppm/lit) used against Protein contentof fish and results showed the gradual decrease in the protein content, ranging (106.14 91.65 mg/gm) for 10 ppm/lit for (24 hrs 96 hrs) and (103.90 - 88.13 mg/gm) for 15 ppm/lit respectively.

Toxicological Effects of Lead and Zinc on the Antioxidant Enzyme Activities of Post Juvenile Clarias gariepinus

Toxicological effects of sub lethal concentrations of lead and zinc salts (Pb(NO3)2 and ZnCl2) on the antioxi- dant enzymes of post juvenile Clarias gariepinus in laboratory bioassays was investigated, using the liver. Oxidative stress enzymes and substrates (Glutathione-S-Transferase (GST), Glutathione (GSH), Superoxide dismutase (SOD), and Catalase (CAT) ) showed irregular activities during the first two weeks of the experiment, but a significant variation (p<0.05) from levels detected in controls after 28 days in fishes exposed to both metals. Increased levels of GST-GSH and reduced levels of SOD and CAT occurred in fishes exposed to ZnCl2 as compared to control while there were no variations in the levels of Malondialdehyde (MDA). In fishes exposed to Pb(NO3)2 however, GST-GSH, SOD, CAT and MDA all reduced when compared to control. There is need for more research on the oxidative defense response of Clarias gariepinus to persistent levels of high concentrations of heavy metals .There is also a need for comparison of existing field and laboratory studies so as to fully exploit the bio markers of oxidative stress as indicators of environmental pollution in tropical fresh water systems.

Sublethal concentrations of azoles induce tri transcript levels and trichothecene production in Fusarium graminearum

The effect of sublethal concentrations (below the recommended field doses) of propiconazole and tebuconazole on the amount of tri transcripts and accumulation of trichothecenes by three Fusarium graminearum isolates of 3ADON, 15ADON, and NIV chemotypes was examined on yeast extract sucrose agar (YES) medium. RT-qPCR analyses showed higher tri4, tri5, and tri11 transcript levels in cultures of all three F. graminearum isolates supplemented with sublethal concentrations of azoles as compared to those in nontreated control, although the fold changes in the amount of tri transcripts differed according to the type of azole used. Mycotoxin analysis revealed higher increase in trichothecene accumulation in most of the tebuconazole-treated samples of all chemotypes tested. A huge increase in all trichothecene compounds was revealed in samples of all F. graminearum isolates treated with 5mgL(-1) of tebuconazole. An inducing effect of azoles on trichothecene accumulation in the grain was confirmed in an in planta experiment; however, the results obtained were inconsistent. A higher amount of trichothecenes and fungal DNA was quantitated in two grain samples treated with sublethal propiconazole concentrations. In contrast, no significant increase in trichothecene levels was revealed in grain samples treated with sublethal concentrations of tebuconazole.

Acute toxicity and effects of sub-lethal malathion exposure on biochemical and haematological parameters of Oreochromis niloticus

The specimens of Oreochromis niloticus were exposed to Malathion to determine the lethal concentration (LC50) value and effects of sub-lethal concentrations on haematological and biochemical parameters. The LC50 value was registered as 1.06 mg/l. Fishes exposed to sub-lethal concentrations (0.12, 0.23 and 0.46 mg/l) for 6 weeks revealed that the pesticide causes alterations in various blood parameters. Red blood cell (RBC) and white blood cell (WBC) counts, haemoglobin concentration and haematocrit values were decreased. Plasma glucose and cholesterol level was elevated whereas plasma protein was decreased in exposed fish. Alanine amino-trasferase (ALT) activity was increased in the fish exposed to Malathion. Key word: Malathion, bioassay, biochemical and haematological changes,Oreochromis niloticus.

Sublethal Effects of Chromium on Enzymatic Activities of the African Catfish: Clarias Gariepinus (Burchell, 1822)

The effect of sublethal concentration (0.00, 2.00, 4.00 and 8.00 mg/l) of chromium was determined on the activities of some enzymes (creatine-kinase, lactate dehydrogenase, cholinesterase, gamma glutamyltransferase) in the plasma, liver and kidney of the exposed juvenile African Catfish Clarias gariepinus (length 23.00±0.86 cm and weight 96.97±5.31 g respectively) after the 7 days exposure period. The activity of lactate dehydrogenase was significantly (p 0.05) in plasma and liver and a significant decrease (p 0.05) in plasma, liver and kidney except liver creatine kinase that was significantly decreased. Generally, the activities of the determined enzymes were most significant in the liver than in plasma and kidney. Therefore, sublethal concentrations of chromium have some deleterious effect on the basic activities of enzymes of the plasma, liver and kidney of Clarias gariepinus as revealed in this investigation.