Larvicidal potential of different solvent extracts and oleanolic acid derivative from Coccinia indica against vector mosquitoes

The mosquito larvicidal activities of different solvent extracts (chloroform, ethyl acetate, and methanol) from the leaves of Coccinia indica were studied. Among the extracts tested, the methanol extract showed the highest larvicidal activity against early fourth instar larvae of Culex quinquefasciatus (LC₅₀?=?142?mg?L^?1), Aedes aegypti (LC₅₀?=?158?mg?L^?1) and Anopheles stephensi (LC₅₀?=?161?mg?L^?1) after 24?h of exposure period. The lowest larval mortality was observed with the ethyl acetate extract with the LC₅₀ values of 927, 872, and 730?mg?L^?1 against Cx. quinquefasciatus, Ae. aegypti, and An. stephensi, respectively. The chloroform extract showed the moderate larvicidal activity against the mosquito species tested with the LC₅₀ values from 446 to 546?mg?L^?1. A new triterpene was isolated from the methanol extract using bio-assay guided separation and identified as an oleanolic acid derivative by NMR, IR and mass spectral studies. The compound showed prominent larvicidal activity against Cx. quinquefasciatus, Ae. aegypti and An. stephensi with the LC₅₀ values of 5.6, 5.0, and 4.8?mg?L^?1, respectively. The results of the present investigation offer an opportunity for developing alternatives to rather expensive and environmentally hazardous organic insecticides.     

Evaluation of the toxicity of tetrabromobisphenol A and some of its oxidation products using a micro-scale algal growth inhibition test

A micro-scale algal growth inhibition (μ-AGI) test using a common micro-plate based fluorometric detection was used to demonstrate the effects of humic substances (HSs) on the toxicity of tetrabromobisphenol A (TBBPA) and its oxidative decomposition products 2,5-dibromo-1,4-benzoquinone (2,5-DBBQ), 2,5-dibromohydroquinone (2,5-DBHQ), 2,6-dibromobenzoquinone (2,6-DBBQ), and 2,6-dibromophenol (2,6-DBP) to Pseudokirchneriella subcapitata. The EC₅₀ values were: EC_50(TBBPA) = 7 mg L^?1, EC_50(2,5-DBHQ) = 7 mg L^?1, EC_50(2,5-DBBQ) = 19 mg L^?1, EC_50(2,6-DBP) = 49 mg L^?1, and EC_50(2,6-DBBQ) = 13 mg L^?1. The toxicity of the chemicals was slightly lower in the presence of HA. The toxicity of TBBPA decomposed by a biomimetic catalytic system consisting of iron (III) 5,10,15,20-tetrakis (p-sulfonatophenyl) porphyrin (Fe(III)-TPPS) and KHSO₅ was also evaluated using P. subcapitata and Chlamydomonas reinhardtii.     

Effects of bisphenol A on Gammarus fossarum and Lumbriculus variegatus in artificial indoor streams

The impact of bisphenol A (BPA) on Gammarus fossarum and Lumbriculus variegatus was studied in four artificial indoor streams (0, 5, 50 and 500?µg?L^?1 BPA, nominal) over 103 days in a pulse–dose exposure scenario (weekly BPA application). For G. fossarum populations at day 103, the proportions of juveniles and of breeding females from the highest BPA treatment were in tendency reduced. For individually exposed gammarid pairs an EC₁₀ of 17?µg?L^?1 BPA (nominal) for the proportion of reproductive females in the fourth brood was determined. During the first three broods, the largest brood size occurred at the highest BPA concentration, whereas in the fourth brood it decreased concentration-dependently (fourth brood EC₁₀?=?5?µg?L^?1 BPA, nominal). Effects on L. variegatus were a reduced population growth (103?d-EC₁₀ of 2?µg?L^?1 BPA, nominal) and an increase in dry weight and the number of segments in large, complete worms.     

The role of root organic acids in the tolerance of Festuca rubra to zinc,lead and cadmium

Abstract

Festuca rubra L. plants are pseudometallophytes colonizing abandoned Pb/Zn mine areas, successfully employed in phytostabilization. To study the contribution of low-molecular weight organic acids to metal tolerance, F. rubra plants were grown for three months in hydroponics with Cd (1.8, 18 and 36 µmol?L^?1), Pb (50, 250 and 500?µmol?L^?1) and Zn (0.3, 3 and 6?mmol?L^?1), separately, and in ternary combination (18?µmol?L^?1 Cd + 250?µmol?L^?1 Pb + 0.3?mmol?L^?1 Zn). The roots retained most of the metals but their distribution from shoot to root was altered when the plants were treated with the ternary combination. The main organic acids in roots were citrate and malate. At the lowest concentrations, the metals caused small reductions in biomass, had no effects on photosynthetic pigments nor on malondialdehyde, but led to increases in root organic acids. At higher concentrations, phytotoxic responses were observed, associated with a decline of citrate and malate in the roots.     

镉胁迫对脊尾白虾的毒性效应研究

为揭示重金属镉对脊尾白虾的毒性效应,采用急性毒性实验方法,研究了不同浓度镉(Cd~(2+))对脊尾白虾(Exopalaemon carinicauda)血清氧化应激相关生理指标的活性以及肌肉组织中腺苷酸转移酶基因(ANT)和热激蛋白70基因(HSC70)表达水平的影响。共设置4个Cd2+浓度胁迫(0、0.0002、0.001、0.005 mmol·L~(-1)),分别在0、3、6、9、12、24、36、48、72和96 h共10个时间点对相关指标进行测定。结果显示:不同浓度镉胁迫下,脊尾白虾血清中H_2O_2含量、MDA含量和GSH含量均表现为先升高后降低的趋势,H2O2含量在胁迫3 h时即出现明显的升高,而MDA和GSH则均在9 h时出现升高趋势,表现为一定的滞后性。H2O2含量在0.005 mmol·L~(-1)胁迫3 h时出现峰值,MDA含量在0.005 mmol·L~(-1)胁迫9 h时出现峰值,GSH含量在0.001mmol·L~(-1)胁迫48 h时出现峰值,且均与对照组存在显著性差异(P0.05)。HSC70基因的表达量在不同浓度胁迫下均表现为先升高后降低的趋势,且均在24 h时达到峰值,具体表达量水平的顺序为:0.0002 mmol·L~(-1)0.001 mmol·L~(-1)0.005 mmol·L~(-1)。ANT基因的表达量在不同浓度下则均表现为明显的下调趋势。由此可见,急性Cd~(2+)胁迫不仅影响脊尾白虾的氧化应激相关生理指标,还影响机体内组成型HSC70及与能量传递有关的ANT基因的表达水平。     

Iron-doped copper 1,4-benzenedicarboxylate as photo-Fenton catalyst for degradation of methylene blue

Abstract

A metal-organic framework of iron-doped copper 1,4-benzenedicarboxylate was synthesized and, for the first time, utilized as a heterogeneous photo-Fenton catalyst for degradation of methylene blue dye in aqueous solution under visible light irradiation. The synthesized materials were characterized by scanning electron microscopy, Fourier-transform infrared spectroscopy, X-ray diffraction and energy-dispersive X-ray spectroscopy. The influence factors, kinetics, and stability of the synthesized catalysts were investigated in detail. Iron-doped copper 1,4-benzenedicarboxylate showed higher degradation efficiency than pure copper 1,4-benzenedicarboxylate. An almost complete degradation was achieved within 70?min under visible light irradiation at a solution pH of 6, a catalyst loading of 1?g?L^?1, a H₂O₂ dosage of 0.05?mol L^?1 and methylene blue concentration of 50?mg?L^?1. Recycling studies demonstrated that the iron-doped copper 1,4-benzenedicarboxylate is a promising heterogeneous photo-Fenton catalyst for long-term removal of methylene blue dye from industrial wastewater.     

Acute and chronic toxic effect of lead (Pb) and zinc (Zn) on biomarker response in post larvae of Penaeus monodon (Fabricus, 1798)

Metal pollution produces damage to marine organisms at the cellular level possibly leading to ecological imbalance. The present investigation focused on the acute and chronic toxicity of lead (Pb) and zinc (Zn) by examining the effects of biomarker enzymes in post-larvae of Penaeus monodon (Tiger prawn). Antioxidant biomarker responses such as lipid peroxidation (LPO) and catalase (CAT) activity for Pb and Zn were determined following chronic exposure. Acute Lethal Concentration ₅₀ (LC₅₀) values observed in the study at 96?h for Pb and Zn at 5.77?±?0.32?mg?L^?1 and 3.02?±?0.82?mg?L^?1, respectively. The estimated No Observed Effect Concentration and Lowest Observed Effect Concentration values for Pb were 0.014 and 0.029?mg?L^?1 and that recorded for Zn was 0.011 and 0.022?mg?L^?1, respectively. Among the two metals studied, toxicity of Zn was found to be greater to P. monodon than Pb. The activities of antioxidant defense enzymes and total protein content differed significantly from control following exposure to both metals. Overall, the biomarker studies demonstrated that alterations in antioxidant enzymes and induction of LPO reflect the consequences of heavy metal exposure in P. monodon.     

Differential effects of UV-B radiation fluence rates on growth,photosynthesis, and phosphate metabolism in two cyanobacteria under copper toxicity

This work was undertaken to ascertain the impact of different fluence rates of ultraviolet-B (UV-B) radiation on two cyanobacterial biofertilizers, Phormidium foveolarum and Nostoc muscorum, growing under copper toxicity. Copper (2 and 5?µmol?L^?1) and high UV-B fluence rate (UV-B_H; 1.0?µmol?m^?2?s^?1) decreased the growth, pigment content, photosynthetic oxygen yield, phosphate uptake, and acid phosphatase activity in both the strains analyzed after 24 and 72?h of experiments, and combined exposure further enhanced the toxic effects. Respiration and alkaline phosphatase activities were stimulated appreciably. The damaging effect was shown on the order on pigments: phycocyanin?>?chlorophyll a?>?carotenoids, and on photosystems: whole chain photosynthetic reaction?>?photosystem II?>?photosystem I. Partial recovery in the photosystem II activity in the presence of artificial electron donors; diphenyl carbazide (DPC), hydroxylamine (NH₂OH), and manganese chloride (MnCl₂) pointed out the interruption of electron flow on the oxidation side of photosystem II. Unlike UV-B_H, low UV-B fluence rate (UV-B_L; 0.1?µmol?m^?2?s^?1), rather than causing damaging effect partially, alleviated the toxic effects of Cu. This study suggests that the cyanobacterium P. foveolarum is less sensitive against UV-B_H and excess Cu (2 and 5?µmol?L^?1), thus P. foveolarum may be used as a biofertilizer for sustainable agriculture.     

Application of microcosm and species sensitivity distribution approaches in the ecological hazard assessment of 4-tert-butylphenol

In order to evaluate the ecological hazard of 4-tert-butylphenol (4-TBP), species abundances and physicochemical properties were monitored for 63 days in a microcosm system containing planktonic algae, rotifers, shrimps and Daphnia. The 63 days-NOEC (no observed effect concentration) of 4-TBP for this system was calculated. At the same time, species sensitivity distribution curves were constructed based on the toxicity data of EC₁₀, EC₅₀ and NOEC derived from laboratory single-species toxicity tests, which further gives no obvious hazard concentrations for 95% species in the ecosystem (HC₅). In both the microcosm and the single-species tests, the shrimp (Neocaridina sp.) was the most sensitive species to 4-TBP exposure, while most algae species were relatively insensitive compared to the zooplankton. For the microcosm exposed to 4-TBP, significant changes occurred to the community structure instead of the community function, resulting in a NOEC_microcosm of 265.38?μg?L^–1 which approached the EC₁₀-based HC₅ (0.376?mg?L^–1). Nevertheless, EC₅₀-based HC₅ was higher than the NOEC_microcosm, and the NOEC-based HC₅ was lower. The data showed that the EC₁₀-based HC₅ was protective at the similar level with the result of microcosm for 4-TBP, providing supportive data for chemical risk assessment.     

Effects of three different nanoparticles on bioaccumulation,oxidative stress,osmoregulatory, and immune responses of Carcinus aestuarii

Abstract

In this study, the toxicity of CuO (40?nm), α-Al₂O₃ (40?nm), and α-Fe₂O₃ (20–40?nm) nanoparticles was comparatively investigated on Carcinus aestuarii. Crabs were semi-statically exposed to 1?mg/L of each for 14?days and their accumulation and distribution in tissue and hemolymph, potential oxidative stress mechanism, total hemocyte counts and types, and the osmoregulatory and ionoregulatory responses were determined. The tissue distribution of CuO nanoparticles was hepatopancreas?>?hemolymph?≥?gill?> muscle, for α-Fe₂O₃ gill?>?hepatopancreas?>?muscle?> hemolymph, and for α-Al₂O₃ gill?>?muscle?≥?hemolymph?> hepatopancreas. While α-Al₂O₃ and α-Fe₂O₃ NPs, induced lipid peroxidation and changes in antioxidant enzyme activity in the hepatopancreas tissue, the oxidative damage caused by the CuO nanoparticles was minimal. All three nanoparticles, copper in particular, elicit osmoregulatory and ionoregulatory toxicity at this concentration, due to the inhibition of Na⁺, K⁺-ATPase activity in the gill and depletion of hemolymph and carcass ion concentrations.     

Synthesis and antibacterial activity of a Fe3O4–AgCl nanocomposite against Escherichia coli

In this investigation, Fe₃O₄ magnetic nanoparticles (MNPs) were prepared by the alkalinization of an aqueous medium containing ferrous sulfate and ferric chloride. In the next step, a Fe₃O₄–AgCl magnetic nanocomposite was fabricated by the drop-by-drop addition of silver nitrate solution into a NaCl solution containing Fe₃O₄ MNPs. All prepared nanoparticles were characterized by transition electron microscopy (TEM), X-ray diffraction (XRD), and energy-dispersive X-ray spectroscopy (EDS). Both particle types varied in size from 2.5 to 20?nm, with an average size of 7.5?nm for Fe₃O₄ MNPs and 12.5?nm for Fe₃O₄–AgCl nanocomposites. The antibacterial effect of the Fe₃O₄ MNPs and fabricated Fe₃O₄–AgCl nanocomposites against Escherichia coli (ATCC 35218) were investigated by conventional serial agar dilution method using the Müller–Hinton Agar medium. The minimum inhibitory concentration was 4?mg?mL^?1 for Fe₃O₄ MNPs and 2?mg?mL^?1 for the Fe₃O₄–AgCl magnetic nanocomposites. Time-kill course assays showed that the Fe₃O₄–AgCl magnetic nanocomposites successfully killed all inoculated bacterial cells during an exposure time of 60?min. The antibacterial activity of recycled Fe₃O₄–AgCl magnetic nanocomposites over four 60?min cycles of antibacterial treatment was further tested against E. coli by the colony-forming unit (CFU) method. The antibacterial efficiency of the nanocomposites was constant over two cycles of antibacterial testing.     

Acute toxicity of benzophenone-type UV filters and paraben preservatives to freshwater planarian,Dugesia japonica

Fourteen benzophenone-type UV filters and four paraben preservatives were selected to examine their acute toxicities on Dugesia japonica. The 48-h LC₅₀ values for planarians exposed to benzophenone-type UV filters can be ranked as oxybenzone?>?mexenone?>?5-chloro-2-hydroxybenzophenone?> 2,4-dihydroxybenzophenone?>?2-hydroxybenzophenone?>?dioxybenzone?>?benzophenone?>?2,2′,4,4′-tetrahydroxybenzophenone?>?4-hydroxybenzophenone?> 3-hydroxybenzophenone?>?4,4′-dihydroxybenzophenone?>?2,2′-dihydroxy-4,4′-dimethoxybenzophenone?>?2,3,4-trihydroxybenzophenone?>?sulisobenzone with a range from 0.9 to 145?mg?L^?1 with a similar sequence for the 96?h LC₅₀ values, ranging from 0.5 to 77?mg?L^?1. The 48 and 96?LC₅₀ values for planarians exposed to paraben preservatives can be ranked as butylparaben?>?propylparaben?>?ethylparaben?>?methylparaben. Among all the tested chemicals, oxybenzone was the most toxic and sulisobenzone the least toxic chemical to planarian at each exposure period. Most benzophenone-type UV filters are toxic to aquatic animals with 48?h LC₅₀ values less than 10 mg?L^?1, except for 2,2′-dihydroxy-4,4′-dimethoxybenzophenone, 2,3,4-trihydroxybenzophenone, and sulisobenzone. Because of their common occurrence in aquatic environment, more studies on aquatic toxicities of benzophenone-type UV filters and paraben preservativs are needed to provide important information to adequately assess their ecological risk.     

Uptake and toxicity of some pesticides on three freshwater fishes (Oreochromis niloticus,Clarias gariepinus and Chrysicthys nigrodigitatus)

Studies were carried out to determine the toxicity of some selected pesticides on fresh water fish in a tropical environment. The uptake of the pesticides lindane, pentachlorophenol (PCP), and propoxur, which are frequently used by farmers and industrialists were studied in concrete ponds at the University of Cape Coast, in Ghana. The fishes used for the study were Oreochromis niloticus, Clarias gariepinus, and Chrysicthys nigrodigitatus, and were obtained from cultured ponds in the Cape Coast District and Mankessim in the Central Region and Weija Dam, in the Greater Accra region of Ghana. Single high lethal concentration (SD) or acute treatment and cumulative/chronic (or multiple minor) lethal concentration (CD) treatment were employed in administering the pesticides to the fishes via water. Gas chromatograph (GC) Electron Capture Detector (ECD) analysis was done on the dead fishes to see the extent of ingestion. The LC₅₀ values obtained for lindane on the three fish samples were as follows: Chrysicthys?–?0.38?mg?L^?1; Oreochromis?–?0.42?mg?L^?1, and Clarias?–?1.2?mg?L^?1. Mortalities occurred in fish within 3–5 days of application. For the PCP on Chrysicthys, Oreochromis, and Clarias species the LC₅₀ values were 0.42, 0.32 and 0.64?mg?L^?1, respectively for over a 2–3 day period. For a three-time influx period of propoxur the LC₅₀ for Chrysicthys, Oreochromis, and Clarias, were 22.0, 30.40, and 45.04 (all in mg?L^?1), respectively. The results obtained indicated that the pesticides had adverse effects on the general growth and reproduction of fishes. Gonadosomatic indices also showed that the pesticides affected the development of the body, the gonads, and their reproduction.     

Rice seedlings under cadmium stress: effect of silicon on growth,cadmium uptake,oxidative stress,antioxidant capacity and root and leaf structures

In this study, the effect of silicon (Si) addition on cadmium (Cd) toxicity in rice seedlings was investigated. After a series of screening experiments, 50 μmol·L^?1 of Cd and 10 μ mol·L^?1 of Si were selected. Treatment of rice seedlings with Cd (50 μ mol·L^?1) resulted in significant accumulation of this metal in roots and shoots. The data revealed that accumulation of Cd resulted in oxidative stress in rice seedlings as evidenced by increased accumulation of hydrogen peroxide (H₂O₂) and malondialdehyde (MDA; a peroxidation product of lipids). However, addition of Si (10 μ mol·L^?1) together with Cd prevented accumulation of Cd, H₂O₂ and MDA. Antioxidant capacity was decreased by Cd but enhanced by Si addition. Cd decreased the length and frequency of root hairs, stomatal frequency, and distorted leaf mesophyll cells and vascular bundles. However, addition of Si together with Cd reduced these abnormalities. The results showed that addition of exogenous Si protected rice seedlings against Cd toxicity by preventing Cd accumulation and oxidative stress (H₂O₂ and MDA accumulation) by increasing Si accumulation and antioxidant capacity, which maintained the structure and integrity of leaf and root.     

Immunotoxic effect of arsenic trioxide on Caenorhabditis elegans

A Pseudomonas aeruginosa–Caenorhabditis elegans pathogenesis model was utilized to assess immunotoxic effects of arsenic trioxide (As₂O₃). After 2 h of As₂O₃ exposure, 500 µmol L^?1 and 1 mmol L^?1 As₂O₃ treatment significantly decreased median survivals of C. elegans (10 h after L4/adult molt). However, 2 h of As₂O₃ exposure caused no significant changes in the survivals rates of C. elegans (2 h after L4/adult molt). Notably, a significant dose-related immunoenhancement was observed in C. elegans (2 h after L4/adult molt) after 12 h of arsenite exposure.     

In vitro kinetic characterization of inhibition of acetylcholinesterase by organophosphate and carbamate compounds in food animals

Organophosphate, dichlorvos (2,2-dichlorovinyldimethylphosphate, DDVP), and diazinon (DZN) as well as carbamates are currently found in contaminated water, dust, soil, agricultural waste, and elsewhere in the environment, and can be harmful after accidental or deliberate exposure. Intoxication by these compounds causes a generalized cholinergic crisis due to the inhibition of acetylcholinesterase (AChE), whose major physiological role in mammalian tissues is in nervous transmission. The half-maximal inhibitory concentration (IC₅₀) was found to be higher for carbaryl than DDVP and DZN, about 3–4 times in liver and about 4–6 times in muscles. The half time (t _1/2) of inhibition (8?µmol?L^?1 DDVP or DZN; 40?µmol?L^?1 carbaryl) ranged between 4 and 16?min and decreased as follows: pig?>?cattle?>?sheep for liver tissue, and cattle?>?sheep?>?pig for muscle. Rate constants of inhibition (k _i) ranged between 43?×?10^?3 and 168?×?10^?3?min^?1 for liver and from 46?×?10^?3 to 115?×?10^?3?min^?1 for muscles. Very little residual AChE activity (<6.1%) was seen in liver, but more was seen in muscle (<17%).     

Quantal response of Paleomonetes africanus in locally formulated drilling mud lubricants

The toxic potency of three locally formulated drilling mud lubricants against Paleomonetes africanus, a brackish water crustacean commonly found in the oil producing Niger Delta (Nigeria), was evaluated. A 96?h exposure to quantal (lethal) doses of the mud lubricants gave LC₅₀ (median lethal concentration) of 350, 620 and 210?mg?L^?1, respectively. The mud lubricant with the highest molecular weight of 40,000?g?mol^?1 (lubricant 2) had the least toxicity on the organisms, attributable to the reduced rate of diffusion into the vital cells of the test organism. The higher toxicity of lubricant 3 over lubricant 1, despite its higher molecular weight, might be as a result of its higher acid value of 21.60?mg?KOH?g^?1. The results show that the test lubricants would be environmentally friendly within the baseline concentrations and lethal times (LT₅₀) measured.     

Endosulfan reduces fertilization success and causes abnormal embryo development to zebrafish

Abstract

Reproductive and teratogenic effects of endosulfan were investigated by exposure of mature breeding zebrafish (Danio rerio) to environmentally relevant concentrations of 0.01–1.2?μg L^?1 and monitoring their spawning, fertilization success, and gonad histology. Fertilization success was negatively correlated to duration of exposure at endosulfan concentration of 1.2?μg L^?1. No apparent effect was observed on fish gonads after histological examination. Teratogenic effects were assayed by exposing newly spawned embryos to endosulfan at 1.0–200?μg L^?1 and determining coagulation, tail development, eye formation, and spontaneous movements 24?h after fertilization; pigmentation, heart rate, edema, and mortality after 48?h and hatch time, mortality, and spinal deformations after 144?h. At 50–100?μg L^?1, endosulfan caused impaired tail development and differentiation, and at 10–200?μg L^?1 spinal deformation and increased mortality, depending upon the timing of exposure.     

Effects of Matricaria chamomilla L. on lipid peroxidation,antioxidant enzyme systems,and key liver enzymes in CCl4-treated rats

In this study, we investigated the effects of Matricaria chamomilla L. extract (MCE) on lipid peroxidation, antioxidant enzyme systems, and several liver enzymes in carbon tetrachloride (CCl₄)-treated rats. Rats were divided into five groups. The first group (control group) was fed on standard feed. The rats in the other groups (CCl₄, MCE50, MCE100, and MCE200) were injected intraperitoneally with 0.8?mL?kg^?1 CCl₄. Moreover, rats in the MCE50, MCE100, and MCE200 groups were gavaged with 50?mg?kg^?1, 100?mg?kg^?1, and 200?mg?kg^?1 MCE, respectively. Serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels, whole blood malondialdehyde (MDA) and glutathione (GSH) levels, and erythrocyte superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase (CAT) activity levels were measured after 14 days of exposure. ALT and AST in the CCl₄ group increased significantly in comparison to the control group (p?4, MCE50, MCE100, and MCE200 groups at different significance levels. In conclusion, the findings suggest that, depending on the dose administered, MCE decreases CCl₄-induced damage and consequent oxidative stress in rats; it affects the antioxidant system positively.     

Ecotoxicity in Aliivibrio fischeri of Ibuprofen,Omeprazole and their Mixtures

The acute ecotoxic effects of ibuprofen and omeprazole and their mixture have been measured using Aliivibrio fischeri as a biomodel. The toxic effects were also tested after 5 days, and an effect-driven approach was used to analyse the results. The toxic effects of the mixtures were compared with the predictions obtained using concentration addition and independent action mathematical methods.

According to the Passino and Smith classification, the results indicate that ibuprofen can be considered slightly toxic (10<EC₅₀ <100?mg?L^-1), while omeprazole can be denoted as moderately toxic (1<EC₅₀ <10?mg?L^-1) to Aliivibrio fischeri. An overestimation of the actual ecotoxic effect of the mixture was found when the concentration addition and independent action methods were applied. Finally, the effect-driven approach indicated that the transformation products of the studied drugs should be prioritized for risk assessment purposes.