Molluscicidal and antimicrobial activity of Solanum aculeastrum

The methanolic extract of the fresh root bark and berries of Solanum aculeastrum showed significant activity against host snails of schistosomiasis. The berries extract was more potent with 100% snail kill at 50 ppm. Fractionation increased activity with 100% mortality at 20 ppm. The aqueous and methanolic extracts of the berries showed moderate antimicrobial activity, increasing by fractionation.     

Effect of Acibenzolar-S-methyl (ASM) pre-treatment in inducing resistance against Pythium aphanidermatum infection in Curcuma longa

In vitro experiments were carried out to test the efficacy of plant activator Acibenzolar-S-methyl (ASM, a benzothiadiazole derivative; trade name Bion 50WG) against rhizome rot disease of turmeric (Curcuma longa L.) caused by Pythium aphanidermatum. The plant activator was applied as a liquid rhizome pre-treatment followed by inoculation with P. aphanidermatum. Cell death, activities of pathogenesis related (PR) proteins such as cysteine protease (EC 3.4.22), peroxidases (EC 1.11.1.7) both soluble and ionically bound (IB), trypsin inhibitor (EC 3.4.21.1) and chymotrypsin inhibitor (EC 3.4.21.4) were monitored. Rhizome pre-treatment was effective in controlling P. aphanidermatum infection. Anatomical observation of turmeric rhizomes indicated the presence of calcium oxalate deposits in infected tissue and an accumulation of starch grains in response to infection by P. aphanidermatum. Pathogen infection also induced new basic polypeptides corresponding to 18.0 and 41.0 kDa. Induction of protease, protease inhibitors, soluble and ionically bound peroxidase activity was observed after ASM pre-treatment and P. aphanidermatum infection. ASM treatment also enhanced activities of proteases and peroxidase in rhizomes already infected with P. aphanidermatum. Increases in enzyme activities and protease inhibitors occurred much more rapidly and were enhanced in P. aphanidermatum infected rhizomes that were previously treated with ASM suggesting that increased activities of peroxidases and protease inhibitors may play a key role in restricting the development of disease symptoms on the rhizomes infected with P. aphanidermatum as evidenced by a reduction in cell death. Hence, pretreatment with ASM suppress the P. aphanidermatum induced oxidative damage through higher accumulation of peroxidases and induced defense through activities of protease inhibitors thereby, protected turmeric rhizomes from rhizome rot disease.     

An explicit stem profile model for forked and un-forked teak (Tectona grandis) trees in West Africa

Studies on stem profile of teak (Tectona grandis) hardly exist. This can be possibly attributed to the occurrence of forks that is prevalent on teak trees. Stem profile model was therefore developed for teak in West Africa, which took into account the occurrence of forks. Trees were destructively sampled from Moist Evergreen Forest (MEF), Moist Semi-deciduous Forest (MSDF), Dry Semi-deciduous Forest (DSDF) and Savannah ecological zones in both Ghana and Côte d’Ivoire for the study. A single set of parameters could be used explicitly to predict stem profile of any teak tree, irrespective of country, eco-climatic zone, edaphic variables, site index, tree age, stand density and tree competition. The model efficiency and root mean square error (in relative diameter) were calculated to be 0.97 and 0.053, respectively. The relative position of the forks along the stem bole, with respect to total tree height, was highly variable and did not follow any particular trend, except higher value for the first fork in the Moist Evergreen Forest zone. However, average tree height to the first fork decreased along the ecological gradient from MEF, MSDF and DSDF to Savannah. The extent of diameter reduction due to the forks could be predicted. Relative tree form for zero-forked, one-forked and two-forked trees was calculated to be 0.39, 0.36 and 0.33, respectively. Relative loss of stem volume due to one fork and two forks was estimated to be 6.5 and 13.9%, respectively. The measured stem volume when related to the corresponding predicted value yielded coefficient and intercept not significantly different from unity and zero, respectively, with an r² value of 0.97.     

Comparison of extraction methods for the quantification of selected phytochemicals in peanuts (Arachis hypogaea)

Peanuts have been reported to contain bioactive phytochemicals, particularly isoflavones (genistein, daidzein, and biochanin A) and trans-resveratrol. Currently, limited data are available regarding the levels of these bioactive compounds in peanuts with variations in reported levels. The purpose of this study was to compare four methods of extraction [stirring, sonication, Soxtec, and microwave-assisted sonication (MAS)] for runner peanuts. Quantification of the selected compounds was conducted by reverse-phase high-performance liquid chromatography (RP-HPLC). The results showed that the MAS and Soxtec methods extracted significantly higher amounts of the phytochemicals. Also, the defatted peanuts gave significantly higher amounts of the phytochemicals compared to the nondefatted peanuts. The high levels of the isoflavones may be attributed to heat-induced conversion of conjugate glycosides to aglycons. The MAS and Soxtec methods may be used for total isoflavone content quantitation, while sonication or stirring may be the method of choice for quantitation of isoflavone composition (aglycons and glycoside conjugates) in peanuts.     

Salmon oil supplementation in dogs affects the blood flow of testicular arteries

The administration of fish oils is known to cause changes in several reproductive parameters of domestic animals. The ingestion of polyunsaturated fatty acids (PUFAs) of the omega-3 family, such as docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), has been described and correlated with changes in the semen quality, testosterone levels and male fertility. Nevertheless, few studies monitored and registered effects after ceasing supplementation. In the present study, we monitored the Doppler velocimetric and ultrasonographic parameters of nine dogs' testis for 90 days (D90) checking the effect of salmon oil supplementation, and monitoring continued for 60 days more, after ceasing supplementation (D150). Ultrasonographic evaluations comprised determining the Doppler velocimetric parameters, testicular and epididymal volume, and testicular echotexture. Peak systolic velocity (PSV) as well as final diastolic velocity (EDV) in the supratesticular arteries (STA), and marginal artery (MA) increased during the period of treatment and kept that level up to D150. There was no difference between the fish-oil supplementation period and the unsupplemented one regarding the testicular and epididymal volume and echogenicity and heterogeneity characteristics. A negative correlation was found between heterogeneity of testis and sperm production (r = −.41, p = .008). Doppler velocimetry indices were affected by the supplementation, leading to an increase in testicular blood flow.     

Degradation of the neolignan, burchellin in the hemolymph of the bloodsucking insect Rhodnius prolixus

The neolignan, burchellin, a natural compound that reduces urine excretion in larvae of the bloodsucking bug, Rhodnius prolixus, a vector of Chagas' disease, is rapidly degraded in the hemolymph of the insect. The main product that accumulates in this tissue has been shown to be piperonyl alcohol. Other catabolites have been identified by GC-MS analysis.     

Tackling black leaf streak disease and soil fertility constraints to enable the expansion of plantain production to grassland in the humid tropics

In Central Africa, plantain is traditionally grown after a forest fallow. Given increasing urban demand and a lack of forest fallows near urban centres, as well as poor roads and environmental concerns to reduce pressure on forests, research is needed to identify suitable shade, fertility management and cultivars to shift production of plantain to grasslands and to reduce losses to diseases such as black leaf streak disease (BLSD). Effects of light level (full, 67%, 33% light), and nitrogen (N)-amendment on BLSD-tolerant (FHIA-21) and BLSD-susceptible (Batard) cultivars planted on soil from paired grassland and forest sites were determined. BLSD and growth were monitored until 5 months after planting. Three months after planting, leaf area attacked on cultivar FHIA-21 was less than half that on Batard. Plants grown under 33% and 67% light had less leaf area attacked (2.9% and 4.6%, respectively) than those grown in full light (7.3%). Leaf area and dry matter (DM) were higher under shade and when grown on forest soils. Compared to growing BLSD-susceptible plantain on forested land under shade, a shift onto grasslands and a reduction in shade use is predicted to reduce yields. Using cultivar FHIA-21 may limit, but not eliminate, yield loss.     

Production,Characterization and Biocompatibility of Marine Collagen Matrices from an Alternative and Sustainable Source: The Sea Urchin Paracentrotus lividus

Collagen has become a key-molecule in cell culture studies and in the tissue engineering field. Industrially, the principal sources of collagen are calf skin and bones which, however, could be associated to risks of serious disease transmission. In fact, collagen derived from alternative and riskless sources is required, and marine organisms are among the safest and recently exploited ones. Sea urchins possess a circular area of soft tissue surrounding the mouth, the peristomial membrane (PM), mainly composed by mammalian-like collagen. The PM of the edible sea urchin Paracentrotus lividus therefore represents a potential unexploited collagen source, easily obtainable as a food industry waste product. Our results demonstrate that it is possible to extract native collagen fibrils from the PM and produce suitable substrates for in vitro system. The obtained matrices appear as a homogeneous fibrillar network (mean fibril diameter 30–400 nm and mesh < 2 μm) and display remarkable mechanical properties in term of stiffness (146 ± 48 MPa) and viscosity (60.98 ± 52.07 GPa·s). In vitro tests with horse pbMSC show a good biocompatibility in terms of overall cell growth. The obtained results indicate that the sea urchin P. lividus can be a valuable low-cost collagen source for mechanically resistant biomedical devices.