Effects of mycorrhizal symbiosis and Ulva lactuca seaweed extract on growth, carbon/nitrogen metabolism, and antioxidant response in cadmium-stressed sorghum plant.

In our study on the effect of cadmium (Cd) toxicity (200 µM) on the growth of Sorghum bicolor (L.) Moench plants, cultivated with arbuscular mycorrhizal fungi (AMF) (Glomus intraradices) and/or under seaweed treatment (3% Ulva lactuca extract) (U. lactuca), we found that AMF increased the tolerance of sorghum to cadmium stress, either alone or in combination with the seaweed treatment. Morphological parameters were higher in these two culture conditions, with increased chlorophyll content. AMF reduced Cd accumulation in roots and inhibited its translocation to the aerial part, while seaweed treatment alone significantly increased Cd accumulation in leaves and roots without affecting plant growth compared to stressed witnesses. Treatment with AMF and/or U. lactuca attenuated oxidative stress, measured by activation of superoxide dismutase, and resulted in a significant decrease in malondialdehyde and superoxide ions (O2-) in treated plants. Furthermore, it induced significant alterations in carbon and nitrogen metabolic pathways, with a significant increase in the activity of enzymes such as glutamine synthetase, glutamate synthase (GOGAT), glutamate dehydrogenase, phosphoenolpyruvate carboxylase, aspartate aminotransferase and isocitrate dehydrogenase in the leaves of each treated plant. These results confirm that AMF, U. lactuca algae extract and their combination can improve the biochemical parameters of sorghum under Cd stress, through modification of the antioxidant response on one hand, and improved nitrogen absorption and assimilation efficiency on the other.

Physiological stress responses of European sea bass Dicentrarchus labrax related to changing operations of floating net cages in intensive farming conditions at the Moroccan M'diq Bay.

The present study aimed to quantify and compare in situ the primary and secondary physiological stress responses, related to the changing operations of floating net cages, in both subadult (523 days post hatching [dph]) and adult (916 dph) European sea bass Dicentrarchus labrax under intensive farming conditions in the Moroccan M'diq Bay. The blood levels of cortisol, glucose, total cholesterol, total protein, and lactate, as well as the percentage of haematocrit, were measured before and after this operation. The results showed significantly elevated levels of cortisol and blood glucose in both age groups, whereas total cholesterol and protein levels were unaffected. In fact, blood lactate significantly decreased in subadults, whereas in adults this parameter was not affected by the operation. However, the haematocrit percentages measured after the operation were significantly higher than those found before the operation in both groups of fish, which is attributed to the increased rate of oxygen renewal in the new net cages and the lower water temperature inside the cages. With regard to the age-specific response during this essential operation plasma cortisol, blood glucose, and lactate concentrations, as well as plasma total protein levels, were significantly higher in subadults than in adults, in both pre- and post- stress measurement, with the presence of individual-specific response. It is concluded that aquaculture practices such as changing the aquaculture net cage could have repercussions in terms of the classic physiological responses to stress in D. labrax.

Primary and Secondary Physiological Stress Responses of European Sea Bass (Dicentrarchus labrax) Due to Rearing Practices under Aquaculture Farming Conditions in M'diq Bay, Moroccan Mediterranean: The Case of Sampling Operation for Size and Weight Measurement.

Globally, aquaculture contributes to sustainable food and nutritional stability. However, stress conditions constitute a major threat affecting farmed-fish welfare and fish farms' performances. In this regard, the present study was aimed at measuring and comparing in-situ (offshore) the physiological stress responses caused by recurrent sampling operations for length−weight measurement. Studied fish were European sea bass Dicentrarchus labrax sub-adults and adults reared in intensive farming conditions in M'diq Bay, on the Moroccan Mediterranean coast. The physiological stress response was evaluated by measuring blood biomarkers, including cortisol, glucose, lactate, total cholesterol and total proteins levels, and hematocrit percentage. The hypercortisolemia, hyperglycemia, hyperlactatemia and hypoproteinemia detected in the post-sampling state in both age groups of D. labrax indicated stress tendencies and a high sensitivity to aquaculture practice-related stress factors, with major and minor responses detected in the same age and same stress conditions. It is also interesting to note that the fish age and the time-course of the sampling operation had a statistically significant effect in terms of the physiological response (with p < 0.01 and p < 0.001, respectively). In conclusion, the present study showed that sea bass subjected to various stressful situations in intensive farming conditions displayed a physiological stress response specific to its age, to the individual status, as well as to the duration of stressor.

Mercury, Lead, and Cadmium in the Muscles of Five Fish Species from the Mechraâ-Hammadi Dam in Morocco and Health Risks for Their Consumers.

This study aims to assess the degree of metal contamination (mercury (Hg), cadmium (Cd), and lead (Pb)) in the muscles of five species of fish Esox lucius, Sander lucioperca, Micropterus salmoides, Lepomis macrochirus, and Scardinius erythrophthalmus, from the Mechraâ-Hammadi Dam between July 2017 and May 2018, and to conduct a risk assessment for human consumers. Trace metals were determined by Graphite Furnace Atomic Absorption Spectrometry for the Pb and the Cd and by Cold Vapor Atomic Absorption Spectrometry for the Hg. The results gotten from the study of the muscles of the different fish species show that the higher mean amounts of Cd and Hg were determined in E. lucius, and the maximum mean levels of Pb were detected in S. erythrophthalmus. Results suggested that demersal fishes inhabiting near the sediments and piscivorous fishes with higher trophic level were likely to accumulate higher trace metal concentrations. The general order of bioaccumulation of the trace metals measured in the muscles of the fish species is as follows: Hg > Pb > Cd. Therefore, the bioaccumulation of Hg in fish studied is more important than that of Cd and Pb. Furthermore, these concentrations are higher in summer than in winter for all trace metals. All the values of the trace metals in the muscle tissues are below the maximum limits recommended by the European Community (EC) N° 1881/2006. However, estimation of noncarcinogenic health risks by the target hazard quotient indicated no obvious noncarcinogenic risks to humans that consume those fishes (THQ < 1). Results of THQ and maximum safe consumption indicated that Hg may cause more harm to human by fish consumption especially for E. lucius and S. lucioperca. Therefore, reduced intake of carnivorous fishes should be promoted as part of a healthier diet.

Glucose-mediated protein glycation: Contribution of methanolic extract of Ceratonia siliqua L. in protection and in vitro potential inhibition of acetylcholinesterase.

Chronic hyperglycemia presents the major etiology of diabetes mellitus and related complications mainly Alzheimer's disease, via the protein glycation and toxic products generated. In the current study, we investigated the eventual protective effect of the methanolic extract of Ceratonia siliqua L. (CsME) against glucose-mediated glycation in serum bovine albumin. The multi-stage glycation markers, namely fructosamines and advanced glycation end products (AGEs) levels were monitored along with measurement of thiol groups; moreover, the in vitro acetylcholinesterase (AChE) inhibition potential was carried out. HPLC was also assessed. Rutin was the main phenolic compound found in CsME. CsME showed a good capacity to inhibit AGEs, fructosamines and protected thiol groups against glycation. CsME exhibited a great AChE inhibition activity. In the present study, CsME prevented glucose-induced protein glycation, it also exhibited a good inhibition of AChE, suggesting its DM complications such as memory troubles related to AD. PRACTICAL APPLICATIONS: Neurodegenerative disorders ranging from memory troubles to Alzheimer's disease present the most diabetes mellitus complications and mainly attributed to protein glycation process. Currently, there is a strong trend to search for efficient natural sources of glycation and acetylcholinesterase inhibitors to replace the synthetic ones, whose secondary effects were shown. The present article tries to justify scientifically the wide use of Ceratonia siliqua L. in Moroccan folk medicine, demonstrating that the methanolic extract of leaves from this species presents a promising source of new natural compounds inhibiting acetylcholinesterase and acting in vitro against glycation generated compounds. Furthermore, for the first time, Rutin was the main phenolic compound found in this extract, these encouraging results should be coupled with further studies to integrate it in pharmaceutical formulations. As such, this paper should be of interest to a broad readership, including those interested in Biochemistry, Phytochemistry, pharmacology, and neurosciences.

Prevalence, serotype distribution, and antimicrobial resistance of Salmonella isolated from food products in Morocco.

INTRODUCTION: Salmonellosis is one of the most common foodborne diseases worldwide. The irrational use of antibiotics in medicine and in animal feed has greatly promoted the emergence and spread of resistant strains of non-typhoidal Salmonella. METHODOLOGY: A total of 464 food products were collected in Tetouan from January 2010 to December 2012. The isolation and identification of Salmonella were performed according to Moroccan standard 08.0.116. All isolates were serotyped and were then tested for antibiotic resistance using the disk diffusion method. RESULTS: The microbiological analysis showed that 10.3% of food samples were contaminated with Salmonella. Eleven serotypes were identified: Kentucky 22.9% (11/48), Agona 16.7% (8/48), Reading 12.5% (6/48), Corvallis 8.3% (4/48), Saintpaul 8.3% (4/48), Typhimurium 6.2% (3/48), Montevideo 6.2% (3/48), Enteritidis 4.2% (2/48), and 2% (1/48) for each of Israel, Hadar, and Branderup. Drug susceptibility testing showed that 39.6% of Salmonella were resistant to at least one antibiotic and 60.4% were susceptible to all tested antibiotics. The highest percentage of resistance was found to the following antimicrobial agents: nalidixic acid (27.1%), sulfonamides (25%), amoxicillin (12.5%), amoxicillin/clavulanic acid 12.5%, trimethoprim (10.4%), cephalothin (4.2%), and chloramphenicol (2.1%). CONCLUSIONS: This study revealed a relatively high prevalence of Salmonella in food products in Tetouan and a large percentage of drug-resistant strains. Hygienic measures should be rigorously implemented, and monitoring resistance of Salmonella is required to reduce the risks related to the emergence of multi-resistant bacteria.