Antioxidant activity and enzyme inhibitory potential of Euphorbia resinifera and E. officinarum honeys from Morocco and plant aqueous extracts

Natural products may be applied in a wide range of domains, from agriculture to food and pharmaceutical industries. In this study, the antioxidant properties and the capacity to inhibit some enzymatic activities of Euphorbia resinifera and Euphorbia officinarum aqueous extracts and honeys were assessed. The physicochemical characteristics were also evaluated. Higher amounts of iron, copper and aluminium were detected in E. officinarum honey, which may indicate environmental pollution around the beehives or inadequate storage of honey samples. This honey sample showed higher amounts of total phenols and better capacity for scavenging superoxide anion free radicals and DPPH free radicals as compared with E. resinifera honey, but poorer capacity for inhibiting lipoxygenase, acetylcholinesterase, tyrosinase and xanthine oxidase. The ratio plant mass:solvent volume (1:100) and extraction time (1 - 2 h) were associated with higher total phenols and better antioxidant activities and lipoxygenase, acetylcholinesterase and tyrosinase inhibitory activities, regardless of the plant species. The aqueous extracts had systematically higher in vitro activities than the respective honey samples.

     

Mercury biomethylation assessment in the estuary of Bilbao (North of Spain)

The relationship between the microbial methylation of mercury and the microbial activities in sediments and water collected from the estuary of Bilbao (North of Spain) was studied in three different sampling points and in two different seasons. Three different cultures were prepared with a sediment slurry to distinguish between biotic and abiotic methylation pathways and the variations of the methylmercury concentration and the variations of the population of total number of bacteria (TDC), anaerobic heterotrophic bacteria (AHB), sulphate-reducing bacteria (SRB) and Desulfovibrio were measured. From this work, it can be concluded that the variation of MeHg concentrations is a result of the methylation/demethylation processes in the sediments, and that the abiotic processes have a negligible contribution to those processes. According to the statistical analysis of the results (partial least squares analysis) a significant statistical correlation was established between methylmercury and the SRB counts.     

EEG bioeffects on cochlear deaf from cellular phones

Objectives This paper aims to provide evidence of an inductive electromagnetic bioeffect on the human brain, which is independent from sound waves and produced by mobile phones, in proximal field, through correlating the EEG data obtained from electrodes placed on both normal and cochlear deaf individuals. Methods Two groups of subjects are placed under controlled electromagnetic conditions inside a Faraday chamber, 12 healthy and another 12 suffering from cochlear deafness). Each is sitting on a chair, fitted with additional support, and holding a cellular phone 2 cm away form the right auricular, in order to avoid a thermal effect as much as possible. All of them, relaxed and with their eyes closed, are EEG recorded in a basal state with their mobile phones off. Then, each of them is again recorded under the same conditions but with the mobile on and listening to the same conversation. In order to assess the observed EEG changes, a statistical analysis by means of the FFT (Fast Fourier Transform) was carried out. Results For both, healthy and cochlear deaf, assimilation or integration of the mobile phone signal by some electrodes is to be found. This is due to the increase of amplitudes for alpha and theta waves, whereas the signal is not integrated in other electrodes. By correlating the spectra of frequencies of corresponding EEG records for the same brain areas, we have not observed significative differences for both groups. Conclusions A possible electromagnetic direct inductive, non-thermal, bioeffect on the human brain is observed. This effect is produced by the use of mobile phones and it bears no relation to the sound waves.     

Metallothionein-like metalloproteins in the Baltic clam Macoma balthica : seasonal variations and induction upon metal exposure

Metallothionein-like proteins (MTLs) have been measured by differential pulse polarography every two months during a period of two and half years in the marine bivalve Macoma balthica from two locations of the Western Scheldt Estuary. The MTL concentrations (0.85 to 7.81 mg g⁻¹ dry wt) are comparable to most values found for other marine invertebrates. These concentrations vary significantly with the seasons (higher in winter, lower in summer), which is mainly due to body weight fluctuations. Strong correlations exist between MTL and metal levels. Upon short-term exposure to a mixture of Cd, Cu and Zn, there are on average significant MTL increases, but important seasonal variations have been observed: in winter, the clams are more sensitive to metals, uptake more Cd and Cu and induce more MTL than during the warmer months. Received: 16 May 1997 / Accepted: 6 June 1997     

Effect of the organic loading rate on the performance of anaerobic acidogenic fermentation of two-phase olive mill solid residue

A study of the effect of the organic loading rate (OLR) on the anaerobic acidogenic fermentation of two-phase olive mill solid residue (OMSR) derived from fruits with a low ripening index was carried out in a laboratory-scale completely stirred tank reactor at mesophilic temperature (35 degrees C). Eight experimental runs were carried out at OLRs of 3.2, 5.6, 7.4, 9.6, 11.0, 12.9, 14.0 and 15.1g T-COD/ld, which were equivalent to hydraulic retention times of 50.0, 28.8, 21.8, 16.9, 14.7, 12.4, 11.5 and 10.7d, respectively. The experimental results obtained demonstrated that the optimum value of OLR for the acidogenic fermentation process was 12.9 g T-COD/ld, for which a maximum production of acetic acid was achieved. It was found that inhibition of the process occurred at OLRs higher than 12.9 g T-COD/ld. This was characterized by a significant decrease in the acetic acid concentration in the effluent and an increase in the concentration of other volatile acids that may affect the methanogenic step. The process inhibition was also characterized by the plateau in the curves of the effluent substrate concentration versus the OLR applied. It was found that a first-order kinetics satisfactorily described the influence of non-acetic acid soluble organic matter concentration (S-COD( *)) on the rate of soluble organic matter conversion to acetic acid (R(S-COD)( *)), and the influence of acetic acid concentration (AcH) on the rate of acetic acid production (R(AcH)), while a potential equation type adequately described the influence of acetic acid concentration on the volumetric hydrogen production (R(ACH) ). The kinetic constant for soluble organic matter removal was 0.145 d(-1), while the constant for acetic acid formation was found to be 0.075 d(-1).     

Contamination of the environment by the current disposal methods of mercury-containing lamps in the state of Minas Gerais, Brazil.

This survey describes the degree of environmental contamination resulting from the current disposal methods of mercury-containing lamps. The territory studied for this purpose is the federal state of Minas Gerais, one of the most populated areas in the Brazilian federation of states. The results of this survey derive in part from answers received to a questionnaire mailed out to industrial firms, commercial business enterprises, hospitals and departments of public work. The sampling technique used was a nonprobabilistic (purposive sampling). Three types of disposal were found to prevail: (1) as an addition to corporate waste disposal (garbage), (2) recycling and (3) disposal by other methods. Overall, our study shows that the majority of mercury lamps are being disposed in the metropolitan area of Belo Horizonte, primarily by the public sector, followed by industrial, commercial and hospital sectors. Although recycling constitutes a relatively high fraction of the disposal methods, we find Federal regulations in Brazil regarding the disposal of hazardous, mercury-containing lamps to be far behind the state of technological achievement. This gap has permitted the adoption of disposal measures that are obsolete, incorrect, and a primary cause for the extensive contamination of the ecosystems with harmful effects to human health.     

Piggery waste treatment by using down-flow anaerobic fixed bed reactors

A study of the role of the depth in the performance of laboratory-scale down-flow anaerobic fixed-bed reactors (DFAFBR) was carried out at different nominal hydraulic retention times (HRT _N ) using piggery waste as substrate at different influent concentrations (2, 4, 6 and 8 g COD/L). The profiles of soluble chemical oxygen demand (COD) (SCOD), organic nitrogen (O.N.), ammonia nitrogen (A.N.), pH and electrical conductivity (E.C.) through the reactor depths showed an initial highly active zone, which was located around the first half of the reactor depth, and a second zone with a lower biological activity. It was found that the depth of the active zone decreased as the HRT _N increased and that the slopes of the profiles obtained increased with the rise in the influent concentration. A hydraulic test showed an increase in the dispersion number when the HRT _N increased. The reactors showed a hydraulic pattern between plug-flow and back-mix. The real values of HRT (Θ) also defined as real contact times were determined to be 0.7, 2.1, 3.4, 4.7, 6.4 and 8 days for values of HRT _N of 1, 2, 3, 4, 5 and 6 days, respectively. It was found that the concentration of SCOD within the reactor decreased exponentially with the increase in the value of θ. Additionally, the influent concentration had a strong influence on the SCOD variation concentration, mainly at values of θ under 1.5 days, which corresponded to the first part of the reactors.     

Distribution and bioaccumulation of PAHs in the UNESCO protected natural reserve of Urdaibai, Bay of Biscay

Along 10 campaigns, from June 2002 to September 2004, the concentrations of 16 polycyclic aromatic hydrocarbons (PAHs) were measured in sediments and oysters (Crassostrea sp.) taken from four sites in the Unesco protected natural reserve of Urdaibai (Basque Country, Bay of Biscay). Total PAH concentration ranged from 0.7 to 140 microg kg(-1) (dw) in the case of sediments, and from 300 to 1400 microg kg(-1) (dw) in the case of oysters. During this study, the coast of the Bay of Biscay was severely affected by the Prestige oil spill (November 2002). Presumably, as a consequence of this accident, both spatial and temporal variations of the PAHs, as well as the sources of the PAHs were affected by the oil spill, and this effect was observed in the total concentrations and, especially, in several diagnostic ratios and in multivariate data analysis. Finally, both BAF (bioaccumulation factor) and BSAF (biota-sediment accumulation factor) parameters were calculated to conclude that particulate matter seems to be the most favourable uptake pathway of PAHs in oysters from this estuary.