Accumulation of Microcystin from Oscillatoria limnetica Lemmermann and Microcystis aeruginosa (Kützing) in Two Leafy Green Vegetable Crop Plants Lactuca sativa L. and Eruca sativa.

The use of contaminated water to irrigate crop plants poses a risk to human health from the bioaccumulation potential of microcystins (MCs) in the edible tissues of vegetable plants. The main objective of this study is to determine the concentration of total microcystins (MC-LR and MC-RR) in leafy green plants (Lactuca sativa L. var. longifolia and Eruca sativa) that have previously been irrigated with polluted water. Integrated water samples were collected by cleaned plastic bottles at a depth of about 30 cm from one of the sources of water used to irrigate agricultural lands for crop plants. At the same time, samples from plants were also collected because this water from the lake farm is used for the irrigation of surrounding vegetable plants such as Lactuca sativa L. var. longifolia and Eruca sativa. The dominant species of cyanobacteria in water samples are Microcystis aeruginosa (Kützing) and Oscillatoria limnetica Lemmermann, which were detected with an average cell count 2,300,000 and 450,000 cells/mL, respectively. These two dominant species in water produced two MCs variants (MC-LR, -RR) that were quantified by high-performance liquid chromatography (HPLC). Dissolve and particulate MCs were detected in the irrigation waters by HPLC with concentrations of 45.04-600 µg/L. MCs in the water samples exceeded the WHO safety limit (1 µg/L) of MC in drinking water. In addition, the total concentration of Microcystin in Lactuca sativa L. var. longifolia and Eruca sativa were 1044 and 1089 ng/g tissues, respectively. The estimated daily intake (EDI) of microcystins by a person (60 kg) consuming 300 g of fresh plants exceeded the total daily intake guidelines (0.04 µg kg-1 body weight) for human food consumption. According to the findings of this study, irrigation water and plants used for human consumption should be tested for the presence of MCs regularly through critical and regularly monitored programs to prevent the accumulation and transfer of such toxins through the food web.

Effect of Pb-Contaminated Water on Ludwigia stolonifera (Guill. & Perr.) P.H. Raven Physiology and Phytoremediation Performance.

A laboratory experiment was led to examine the lead bioaccumulation capacity of Ludwigia stolonifera (Guill. & Perr.) exposed to various Pb concentrations (0, 10, 25, 50, and 100 mg/L) for 1, 3, 5, and 7 days. The lead accumulation increased as the metal concentrations in the solution increased and over time, to an extreme accretion of 6840 mg/kg DW(dry weight) at 100 mg/L of lead on the 10 days exposure. The proportion removal efficiency, translocation factor, and bioconcentration factor of the plant were assessed. The maximum bioconcentration factor values (1981.13) indicate that the plant was a Pb hyperaccumulator, and translocation factor values (1.85), which are >1, indicate fit of L. stolonifera for eliminating Pb in Pb-contaminated water. Photosynthetic pigments were decreased with increase of Pb concentration and time exposure. Total chlorophyll content and Chl a/b ratio lowered to between 46 and 62% at 100 mg/L Pb after 10 days exposure. Protein content and soluble carbohydrate indicated a similar trend, which showed the highest decrease (7.26 and 36.2 mg/g FW(fresh weight), respectively) at 100 mg/L of Pb after 10 days. The activity of the antioxidant enzymes superoxide dismutase, ascorbate, and peroxidase was increased significantly in comparison to the control. The results indicate that L. stolonifera is a newly recognized Pb hyperaccumulator (6840 mg/kg DW), but physiological status indicates that the plant is not tolerant to high Pb concentrations.

Interaction between Growth Regulators Controls In Vitro Shoot Multiplication in Paulownia and Selection of NaCl-Tolerant Variants.

The interaction between cytokinin, auxin and GA controlled in vitro shoot multiplication in paulownia was influenced by a medium water potential (Ψ) modulation, where it was modulated using different textures or strengths of MS medium, media of different types (MS, WPM, SH and B5) or NaCl incorporation. The interaction between 2 mg/L BAP and 0.1 mg/L NAA expressed the highest shoot number on each media type, but it was better with media of lower water potential (MS and WPM), and MS medium was the best. Ψ of full-strength semisolid MS medium expressed the highest shoot multiplication. The opposite was detected when Ψ of MS medium was changed using half- or double-strength MS. Ψ of full-strength MS medium in semisolid form resulted in a valuable interaction between 2 mg/L BAP, 0.1 mg/L NAA and 0.1 mg/L GA, leading to efficient shoot formation, and it was associated with an increase in internode length and decrease in stem diameter, which facilitated obtaining synseeds with a high ability to convert. High genetic variation was recorded under long-term culture (14 subcultures). Polymorphism using the ISSR technique was higher than that of RAPD. A further increase in polymorphism was detected when NaCl was used, where five salt-tolerant lines were selected. Some salt-tolerant-selected lines showed one or more amplification products of a specific molecular weight that did not appear in the control. For example, with OPA-07 and OPG-02 RAPD primers, all the salt-tolerant-selected lines showed the appearance of amplification fragments (610 bp and 300 bp, respectively) that were not detected in control.

The Effect of Endophytic Talaromyces pinophilus on Growth, Absorption and Accumulation of Heavy Metals of Triticum aestivum Grown on Sandy Soil Amended by Sewage Sludge.

Sewage sludge improves agricultural soil and plant growth, but there are risks associated with its use, including high heavy metal content. In this study, experiments were carried out to investigate the role of endophytic Talaromyces pinophilus MW695526 on the growth of Triticum aestivum cultivated in soil amended with sewage sludge and its phytoremediation ability. T. pinophilus could produce gibberellic acid (GA) and stimulate T. aestivum to accumulate GA. The results showed that inoculation with T. pinophilus boosted plant growth criteria, photosynthetic pigments, osmolytes (soluble proteins, soluble sugars and total amino acids), enzymatic antioxidants (catalase, superoxide dismutase and peroxidase), K, Ca and Mg. On the other hand, it reduced Na, Na/K ratio, Cd, Ni, Cu and Zn in the growth media as well as in the shoot and root of T. aestivum. The results suggest that endophytic T. pinophilus can work as a barrier to reduce the absorption of heavy metals in T. aestivum cultivated in soil amended with sewage sludge.

Modifications of water status, growth rate and antioxidant system in two wheat cultivars as affected by salinity stress and salicylic acid.

Salicylic acid (SA) has an important role in drought-tolerance in wheat (Triticum aestivum L.) but its relevance to the salinity-tolerance is not well understood. In the present study, possible roles of SA and salinity responses were examined using two wheat cultivars i.e., drought-tolerant Sakha-69 and drought-sensitive Gemaza-1, exposed to 150 mM NaCl. Parameters were determined for growth i.e. fresh or dry mass (FM, DM), osmotic concentration (OC) of organic/inorganic solute, leaf relative water content (LRWC), photosynthesis pigment content (PPC), and selective antioxidant system (AOS) enzyme/molecule that might be involved in the stress remediation. Sakha-69 exhibited salinity tolerance greater than Gemaza-1 and SA ameliorated their salinity stresses like drought stress, suggesting that a common tolerant mechanism might be involved in the stresses. Salinity decreased root growth by 44-52% more strongly than shoot (36-41%) in FM or those in DM (32-35%). SA ameliorated root growth (40-60%) more efficiently than shoot (6-24%) for DM/FM. These results suggested that salinity and SA might target sensitive roots and hence influencing shoot functions. In fact, salinity reduced PPC by 10-18%, LRWC by 16-28%, and more sensitively, OC of inorganic solutes (K+, Ca2+, Mg2+) in shoot (19-36%) and root (25-59%), except a conspicuous increase in Na+, and SA recovered all the reductions near to control levels. SA and salinity increased additively most parameters for OC of organic solutes (sugars and organic acids) and AOS (glutathione and related enzyme activities), like drought responses. However, SA decreased the Na+ and proline contents and catalase activity in a counteracting manner to salinity. It is concluded from this experiment that SA-mediated tolerance might involve two mechanisms, one specific for minerals in root and the other related to drought/dehydration tolerance governed in the whole module systems.

Hepatoprotective activity of Uncaria tomentosa extract against sub-chronic exposure to fipronil in male rats.

The effects of fipronil (FPN) on the liver of rats were studied. Rats (n = 6) were treated with 9.7 mg/kg (1/10 of FPN LD50), and other rats (n = 6) received 120 mg/kg of 10% Uncaria tomentosa extract, while a mixture of 9.7 mg/kg FPN and 120 mg/kg of 10% Uncaria tomentosa extract were administered orally to the rats (n = 6) daily for 6 weeks. Body, hepatic weights, liver enzymes, and lipid profile were determined. Hepatic activities of MDA, TNO, TAC, TNF-α, and IL-6 in liver homogenate were measured. Immunohistochemistry of NF-kB and liver histopathology were performed. Fipronil-treated rats had a significant (P = 0.02) lower weight gain. Moreover, relative liver weight was significantly (P = 0.003) increased in FPN-treated rats. Rats administrated with FPN exhibited a significantly (P = 0.02) higher liver enzymes and promoted levels of MDA, TNO, TNF-α, and IL-6 (P < 0.0001) than that in the other groups. Immunostaining of NF-κB was increased (P < 0.0001) in FPN-treated rats. Interestingly, Uncaria tomentosa alone or with FPN decreased the liver immunostaining of NF-κB. In conclusion, FPN produced liver injury through lipid peroxidation and stimulation of NF-κB. However, Uncaria tomentosa combated the oxidative stress and liver damage induced by FPN via inhibition of NF-κB.

Risk assessment of some organic contaminants: a case study based on food consumption in Tanta and Ismailia cities, Egypt.

The impact of some organic pollutants on some residents of Tanta and Ismailia cities of Egypt through their consumption of vegetables, fruits and fish (Nile tilapia and catfish) was examined. Residues of organochlorine (OCS) and organophosphorus (OPS) as some polychlorinated biphenyls (PCBS) were compared with pesticides as well maximum residue limits (MRLS). Probable health risk to consumers was also assessed. P, P'-DDT, P, P'-DDE, P, P'-DDD, endrin, α-BHC, (lindane), and hexachlorbenzene (HCB) were the most detected organochlorine compounds, but did not exceed MRLs.However, OPS residues were the most frequently detected contaminants. PCBs congeners 28, 70, 52, and 180 were detected in tilapia fish from Tanta, but congeners 28 and 180 were the only detected congeners in samples collected from Ismailia region. ∑PCBS values in all matrices did not exceed MRLS. Hazard index (HI) exhibited unity for all compounds at 50 the decreasing order: catfish > vegetables > fruits > Nile tilapia in Tanta, while in Ismailia the order was Nile tilapia > fruit > vegetables. Results also revealed that risk values for adults were greater than those of children categories.

Metals bioaccumulation in two edible bivalves and health risk assessment.

Our aim was to quantify the bioaccumulation of 13 metals in two edible bivalves (Ruditapes decussatus and Paphia undulata) in Lake Timsah, Egypt. A potential human health risk assessment was conducted to evaluate the hazards from bivalve consumption. Fe, Al, Zn, and Sr had the highest concentrations in the bivalve samples. The levels of Cd were much lower than the maximum permissible level, while Pb concentrations in the two bivalves were nearly two times the permissible level. The extent of bioaccumulation factor was site- and species-specific. For low and high bivalve-consuming groups, the estimated daily intake of Pb and Cd ranged from 0.01 to 0.76 µg/kg/day. For low and high bivalve-consuming groups, hazard quotients (HQs) for metals were found to be less than 1 for both bivalve species, except for Co in the high-consuming group. In conclusion, even though there was no apparent risk to bivalve consumers from being exposed to single metals, there is a risk from being exposed to the 13 studied metals together, especially for high bivalve-consuming groups such as fishermen.

Hazard index, a tool for a long term risk assessment of pesticide residues in some commodities, a pilot study.

Samples of some vegetables were analyzed for pesticides residues using the accredited (QuEChERS) method. The method allowed the determination of 215 compounds of different pesticide chemical groups. LC-MS/MS and GC-MS/MS were used for residues quantification. In a total number of 116 samples, no pesticides residues were detected in 34 samples (29.3%), while 82 samples (70.7%) had detectable pesticide residues, with some samples exceeding the MRLs levels established by the Codex Alimentarius Commission. The hazard index (HI %), representing the long--term risk assessment was in the range of 0.01%-15.04% of the ADI's. The highest exposure was observed for ethion, followed by chlorpyifos, both of them are organophosphates, at 15.04% and 2.45% of ADI respectively. The acute (short-term) exposure was also estimated. Results showed a potential risk for children posed by 3 pesticides, meanwhile, residues of one pesticides showed potential risk to adults (>100% of ARfD). The present work is an attempt to provide a model for the use of WHO template for calculating the short term intake. This model is especially useful for developing countries where information about consumption rate is rather meager.

Residues of organochlorine and synthetic pyrethroid pesticides in honey, an indicator of ambient environment, a pilot study.

Samples of honey were screened to monitor residues of organochlorine and pyrethroid pesticides. The study meant to examine the quality of honey, and to use honey as a bioindicator of environmental contamination. Residue levels were determined by gas chromatography (GC-µECD). Samples had a wide spectrum of organochlorine and synthetic pyrethroids pesticides, with hexachlorobenzene (HCB) as the most frequently detected organochlorine, followed by permethrin, heptachlor epoxide. Only one sample had a concentration of γ-HCH higher than maximum residue limit of honey (0.01 mg kg(-1)). Residues of organochlorines detected, indicate the presence of some fresh supplies, despite the ban imposed on their use. The study confirmed that honey bee and beehive matrices could be used as gauge for monitoring environment contamination. From public health point of view, the observed levels of pesticide residues in honey do not pose a serious health risk to the consumers, but raises questions of the source of organochlorines.

Changes in the water status and osmotic solute contents in response to drought and salicylic acid treatments in four different cultivars of wheat (Triticum aestivum).

Salicylic acid (SA) controls growth and stress responses in plants. It also induces drought tolerance in plants. In this paper, four wheat (Triticum aestivum L.) cultivars with different drought responses were treated with SA in three levels of drain (90, 60, 30% of maximum field capacity) to examine its interactive effects on drought responses and contents of osmotic solutes that may be involved in growth and osmotic adjustment. Under drought condition, the cultivars Geza 164 and Sakha 69 had the plant biomass and leaf relative water content (LRWC) greater than the cultivars Gemaza 1 and Gemaza 3. In all cultivars, drought stress decreased the biomass, LRWC, and the contents of inorganic solutes (Ca, K, Mg) and largely increased the contents of organic solutes (soluble sugars and proline). By contrast, SA increased the biomass, LRWC and the inorganic and organic solute contents, except proline. Correlation analysis revealed that the LRWC correlated positively with the inorganic solute contents but negatively with proline in all cultivars. SA caused maximum accumulations of soluble sugars in roots under drought. These results indicated that SA-enhanced tolerance might involve solute accumulations but independently of proline biosynthesis. Drought-sensitive cultivars had a trait lowering Ca and K levels especially in shoots. Possible functions of the ions and different traits of cultivars were discussed.

Residue levels of DDE and PCBs in the blood serum of women in the Port Said region of Egypt.

An investigation was conducted to detect residues of 1,1-dichloro-2,2-bis(p-chlorophenyl) ethylene (DDE) and polychlorinated biphenyls (PCBs) in blood serum samples collected from a cohort of fasting females attending the health insurance outpatient clinic at Port Said between July 1999 and July 2000. Females involved in the study included 43 females diagnosed with invasive adenocarcinoma of the breast, 21 female suffering benign breast disease, and 11 normal healthy females. Serum was separated and its contents of DDE and PCBs were extracted and determined, using gas chromatography, equipped with electron capture detector. Mean residues of DDE detected in the three examined groups of females were 41+/-5.2, 48+/-6.2 and 31+/-2.5ng/g for breast cancer cases, benign breast disease cases and controls, respectively, indicating some significantly less residues in blood serum of control females. While PCBs residues detected were 54+/-17, 59+/-23 and 61+/-21ng/g, for the three groups, respectively. Residues of DDE detected in all females alike in the present study are about 15 times higher than residues detected in Canada and The Netherlands.