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Objective(s): In this study, the effects of chronic administration of crocin, an active constituent of saffron, on blood pressures of normotensive and desoxycorticosterone acetate (DOCA) - salt induced hypertensive rats, were investigated. Materials and Methods: Five week administration of three doses of crocin (50, 100 and 200 mg/kg/day) and spironolactone (50 mg/kg/day) in different groups of normotensive and hypertensive rats (at the end of 4 weeks treatment by DOCA-salt) was carried out and their effects on mean systolic blood pressure (MSBP) and heart rate (HR) were evaluated using tail cuff method. The duration of effect of crocin on SBP, was also evaluated. Results: Our results indicated that chronic administration of crocin could reduce the MSBP in DOCA salt treated rats in a dose dependent manner. Crocin did not decrease the MSBP in normotensive rats. The data also showed that antihypertensive effects of crocin did not persist. Conclusion: It is concluded that crocin possesses antihypertensive and normalizing effect on BP in chronic administration.

© 2016, Springer-Verlag Berlin Heidelberg.We compared modifications of soil zymography, a new in situ technique to visualize enzyme activities, based on contact of fluorgenic substrate-saturated membranes with soil either through the gel layer (gel zymography) or without gel application (direct zymography). We coupled zymography with quantitative measurements of enzyme kinetics to characterize catalytic mechanisms of β-glucosidase activity at the plant-soil interface including root surface (rhizoplane), rhizosphere, and bulk soil. Direct zymography refined and focused image resolution. The area of hotspots (i.e., spots with most intensive enzyme activity) as well as color intensity ratios estimated using direct zymography exceeded by a factor of 2 the corresponding values obtained with gel zymography. As determined by direct zymography, the percentage of hotspots associated to root surfaces was 58–68 % of total hotspot area. Hotspot area comprised only 6.8 ± 0.1 % of the total area of an image and 9.0 ± 3 % of the root surface area. The intensity of β-glucosidase activity, however, was up to 20 times higher in the hotspots versus bulk soil. The contribution of rhizosphere to β-glucosidase activity of the whole image (77–82 %) was four times higher than the contribution of the root surface. Enzyme kinetic parameters indicated different enzyme systems in bulk and rhizosphere soil. Higher substrate affinity and catalytic efficiency in bulk than in rhizosphere soil suggested relative domination of microorganisms with more efficient enzyme systems in the former. Coupling direct zymography and kinetic assays enabled mapping the two-dimensional (2D) distribution of enzyme activity at the root-soil interface and estimating the catalytic properties of root-associated and soil-associated enzymes.

© 2016 Elsevier B.V.Microbial parameters have been used to monitor changes in soil quality. Soils from four land use systems common in East Africa and present in the Mt. Kilimanjaro region: (1) montane forest, (2) savannah (3) maize fields and (4) Chagga homegardens were used in laboratory incubations to assess the effects of landuse changes on soil quality. Soil organic matter mineralization and the following microbial parameters: microbial biomass C, mineralization quotient, metabolic quotient and activities of four enzymes: β-glucosidase, cellobiohydrolase, phosphatase and chitinase were determined. Microbial biomass C content, β-glucosidase, cellobiohydrolase and chitinase activities were higher in natural systems compared to agricultural soils. High phosphatase activity observed in all land use types reflected strong phosphorus limitation in andic soils of the Mt. Kilimanjaro region. Chitinase activity in montane forest soils was 3 times higher than in Chagga homegardens. Mineralization quotient and cellobiohydrolase activity best exhibited the effect of land-use changes on soil quality in the Mt. Kilimanjaro region. Cellobiohydrolase activity was up to 3 times higher under natural ecosystems compared to agroecosystems. A high percentage of microbial biomass C content in total organic C and low metabolic quotient were observed in Chagga homegarden soils. Soil enzymes (especially cellobiohydrolase) best distinguished between natural and agricultural ecosystems, and are therefore useful for monitoring changes in soil quality. In conclusion, the measured microbial parameters clearly show that the microbial organisms in traditional Chagga homegardens system have high substrate use efficiency. This demonstrates that traditional agroforestry systems promotes soil fertility and are more suitable for agricultural production in the tropics compared to monocropping systems like maize plantations.

© 2015 Elsevier Masson SAS. Microbial and enzyme activities can be used to identify and assess the impacts of changes in land use management on soil quality. However, only few studies have investigated the effects of land use and nutrient additions on enzyme activities and microbial processes in tropical African soils. Glucose and nutrients (N and P) were added to soils (0-20cm) from natural and agricultural ecosystems: (1) savannah, (2) maize fields, (3) lower montane forest, (4) coffee plantation, (5) grasslands (6) Chagga homegardens common at Mt. Kilimanjaro region and East Africa. Microbial biomass and activities of β-glucosidase, cellobiohydrolase, chitinase and phosphatase were monitored over 60 days incubation period. Microbial biomass content and enzyme activities were generally higher in soils under natural vegetation compared to corresponding agricultural soils. Decline in microbial biomass C content over time was higher in natural ecosystems compared to agricultural soils. However, the microbial biomass C content in Chagga homegarden soils was relatively stable. Land use was negatively correlated to β-glucosidase, cellobiohydrolase and chitinase activity, but positively correlated to phosphatase activity. β-glucosidase and cellobiohydrolase, involved in the C-cycle, were the most sensitive to landuse change. Chitinase activity was 2-6 times higher in soils under natural vegetation compared to corresponding arable soils. Phosphatase displayed very high activities in all land use types. This is attributed to the high P retention capacity common for andic soils similar to those occurring at Mt. Kilimanjaro region. Increased P availability stimulated enzyme activities in lower montane forest and Chagga homegarden soils. Overall, microbial biomass and enzyme activities showed a strong decrease with increased land use intensity and should therefore be taken into consideration in monitoring and assessing the impact of land use change at Mt. Kilimanjaro region.

lran's commercial catch on this fish commenced in 1971 and in spite of recent years endeavour to boost the development of kilka fishery, the catch did not exceed 15 thousand tones by year 1991. In this regard a one year survey program conducted in 1991 data collected and stock status identified in Iranian coastline at areas with a seabed depth of 40 to 80 m, in 56 fishing stations spaced at 10 mile intervals along the coast. The survey showed that Clupeonella engruliformis is dominant (91.8 %) followed by Clupeonella grimmi (6.84%) and Clupeonella cultriventris which shared only 1.35% of the total catch. Furthermore 69.95% of Anchovy type kilka, 81.06% of Big eye kilka and 80.88% of common kilka belonged to 2+ and 3+ year class. This major fishing study which carried out in Bandar Anzali using "Catch per Unit Effort" Method, reflects practical variability in fishing and shows that there are more suitable areas with higher densities than Bandar Anzati stations which are yet unexploited. 17 fishing stations from among 56 demonstrate catch rate ranging from 800-1200 kg kilka per unit effort per hour which can h ranked in the first class of kilka yielding grounds, Traditional fishing grounds in Anzali show the catch rate of 400-800 kg per unit effort per hour which is the second class in kilka fishing grounds category. The Iranian coastline bottom topography features sharp slopes which is a favorable habitat for wintering of kilka. The present study shows that possible yearly catch can be promoted up to a ceiling of 100, 1000 metric tons.