Effects of Diet Selection by Goats Grazing on the Vegetation of a Protected Pine Forest in Doñana Natural Park (SW Spain)

We investigated the relationship between feeding selection by goats and changes in plant species abundance in the shrubland of a pine forest in Doñana Natural Park along three years. The abundance of the shrub species was measured using the point-intercept method. Goat preferences for shrub species were determined through direct observation. Goats showed selective feeding, since their browsing behavior was not related to species abundance. Myrtus communis was the overall preferred species (almost half of the bites belonged to this species, despite its low abundance) throughout the monitored years and seasons. Half of the species were selected some years while discarded others; two species were never grazed (Daphne gnidium and Thymus mastichina) and nine others were always ingested below their abundance. Within a year, species were consumed in certain seasons but not in others. The detected changes in species abundance were not related to the feeding preferences of the goats. The influence that grazing selectivity exerts on vegetation composition and abundance has long been recognized, but our study suggests that the mechanical effect of grazing herbivores on vegetation (pawing, scratching, and lying) may portrait a more important role than attributed to date.

Antimicrobial, Antioxidant and Antihemolytic Activities of Two Daphne gnidium Leaves Extracts

In this study, Daphne gnidium leaves extracts were screened for their Phenolic content, antimicrobial, antioxidant and antihemolitic activities. Decoction and maceration were used to obtain the aqueous (Aq E) and the ethanolic extract (Et E), respectively. Total phenolic content was determined using Folin–Ciocalteu reagent. Moreover, a disc diffusion assay and inhibition of mycelial growth test were applied to evaluate the antibacterial and antifungal activity. The extracts were also tested for their antioxidant effects in terms of DPPH, OH, H2O2, β-carotene, and ferrous ion chelating assays. To investigate antihemolytic activity, the 2,2,-azobis (2-amidinopropane) dihydrochloride (AAPH) was used to induce erythrocyte oxidative hemolysis. Results indicated that ethanolic extract (Et E) contains the highest polyphenol content (775.25 μg GAE/mg extract). The Et E inhibited the growth of bacterial strains with inhibition zone diameters from 7 to 15 mm. In contrast, no activities have been found against all fungal strains. In antihemolytic test, aqueous and ethanolic extracts showed almost the same effect with an HT50 value of 106 min. Ethanolic extract was found to be more active in DPPH and β-carotene assays (IC50: 5.76 μg/ml and 70% inhibition respectively). However, the aqueous extract showed a greater effect than the ethanolic one in metal chelating activity assay (IC50: 170 μg/ml), OH scavenging effect assay (IC50: 9.67 μg/ml) and H2O2 scavenging assay (IC50: 133.2 μg/ml).

Hepatoprotective and Curative Activities of Daphne gnidium L. Aqueous Extract Against CCl4-Induced Liver Injury in Rats

Background:: Liver is one of the largest organs of the human body and the main site for intense metabolism and excretion. Liver injury or dysfunction is recognized as a serious worldwide health problem. Daphne gnidium L., medicinal plant widely distributed in Algeria and used by populations in traditional medicine in the treatment of hepatitis and other diseases. Objective:: Protective and curative effects of aqueous extract of Daphne gnidium L. leaves were investigated against carbon tetrachloride (CCl4) induced hepatic damage in rats (Wistar Albino). Method:: This study was conducted on 32 Albino rats, which were divided into four groups; the first served as control. Group II animals were treated intraperitoneally with CCl4 solution (3ml/kg). Group III animals were treated intraperitoneally with CCl4 solutions (3ml/kg) in the first day, and given aqueous Daphne extract orally at a dose level of (300 mg/kg) daily for 7 days (curative activity test). Animals of group IV were orally administered aqueous Daphne extract at a dose level of (300 mg/kg) daily, and on the seventh day treated intraperitoneally with CCl4 solution (3ml/kg) 3 hours after the latest extract administration (preventive activity test). Results:: Our results show that CCl4 significantly increases the relative liver weight, serum values of ALT, AST, ALP, GGT, and Total bilirubin, as well as the hepatic rate of oxidative stress parameters; MDA, CAT activities, and significantly decreases hepatic GSH levels compared to the control group. These results were confirmed by liver lesions observed in histological analyses. Pre-treatment and curative treatment of dose 300 mg / kg of aqueous Daphne gnidium L. extract significantly reduced relative weight, serum levels of ALT, AST, ALP, GGT and Total bilirubin liver rate, CAT activity and increases GSH level. In addition, normal liver architecture has been restored. Conclusion:: The present study demonstrates the hepatoprotective and curative effects of aqueous extract Daphne gnidium leaves against CCl4-induced liver injury in rats by improving the antioxidant status in tissues (liver) and ameliorating the harmful effects induced by CCl4.

EAG Responses of Adult Lobesia botrana Males and Females Collected from Vitis vinifera and Daphne Gnidium to Larval Host-Plant Volatiles and Sex Pheromone

We analysed electroantennogram (EAG) responses of male and female adults of the European grapevine moth Lobesiabotrana (Denis et Schiffermüller) (Lepidoptera: Tortricidae) collected as larvae from grapevine (Vitis vinifera L.) and flax-leaved daphne (Daphne gnidium L.). The host-plant odorants tested were either V. vinifera-specific [1-octen-3-ol, (E)-β-farnesene, (E)-4,8-dimethyl-1,3,7-nonatriene], D. gnidium-specific (2-ethyl-hexan-1-ol, benzothiazole, linalool-oxide, ethyl benzanoate), or were shared by both host-plants (linalool, methyl salicylate). Sex pheromone compounds were also tested. The male response to the major pheromone component (E7,Z9-12:Ac) was higher than to any other stimuli, whereas the response to the minor pheromone components (E7,Z9-12:OH and Z9-12:Ac) was not different from the response to the plant odorants. The female response to pheromone was lower or not different from that to plant odorants. Methyl salicylate elicited a higher response in females and (E)-β-farnesene elicited a higher response than several other plant odorants in both sexes. Non-significant interactions between host-plant odorant and sex indicated an absence of sex specialization for host-plant volatile detection. The lack of a significant interaction between plant volatiles and larval host-plants suggested that there was no specialization for plant-volatile detection between V. vinifera and D. gnidium individuals.

Factores ambientales en la distribución de la seca en la encina (Quercus ilex subsp. ballota) = Environmental Variables in the Distribution of La Seca Disease in the Holm Oak (Quercus Ilex Subsp. Ballota)

La combinación de factores bióticos y abióticos (clima, orografía, litología, competencia interespecífica, etc.) y la patogenicidad de agentes como el hongo Phytophthora cinnamomi Rands han generado la enfermedad fitosanitaria denominada en España como la seca de encinas y alcornoques de la Península Ibérica. El objetivo del presente estudio es el análisis que desempeñan las variables ambientales en el desarrollo de dicha enfermedad y determinar cuáles tienen una mayor influencia en su propagación. Se toma como área de estudio el Monte de Valdelatas, Alcobendas, Madrid (hoja 534 del Mapa Topográfico Nacional a escala 1:50.000. Coordenadas UTM X: X: 442592.51, Y: 4487266.63 zona 30T). Se obtivieron muestras en campo de 100 árboles de Quercus ilex subsp. ballota (50 con apariencia saludable y 50 con síntomas aparentes de enfermedad) azarosamente ubicados en 7 transectos. En relación al modelo estadístico se empleó un modelo binomial cuya variable respuesta se definió como sano/enfermo, según la apariencia del árbol. Así mismo, se manejó el Criterio de Información de Akaike (AIC) con el fin de establecer el mejor modelo. En su caso, presentando un 44% de la varianza (D2 = 0.437) y un valor de 89.68 en AIC. Las principales variables ambientales que interfieren en la enfermedad fueron: proximidad a cursos fluviales, índice de humedad topográfico, cobertura de Daphne gnidium y Quercus ilex subsp. ballota y la edad de los individuos muestreados. Dada la pérdida en la masa forestal de Quercus debido a la enfermedad de la seca, es necesario comprender el comportamiento de dicha enfermedad, así como conocer los factores ambientales que contribuyen a su expansión, pudiendo llegar de tal modo a identificar algún factor inhibidor. The combination of biotic and abiotic factors (climate, orography, lithology, interspecific competition, etc.) and the pathogenicity of agents such as the fungus Phytophthora cinnamomi Rands has generated the phytosanitary disease known as the oak decline (la seca) in holm oak and cork oak stand of the Iberian Peninsula. The aim of this study is to analyse the role played by environmental variables in the development of this disease, and to determine which have a stronger influence in the spread of the disease. Data has been obtained from Monte de Valdelatas, Alcobendas, Madrid (sheet 534 national topographic map, scale 1:50.000, UTM coordinates X: 442592.51, Y: 4487266.63 zone 30T). Field samples were taken from 100 randomly selected Quercus ilex subsp. ballota individuals (50 with a healthy appearance and 50 that showed disease symptoms), located within 7 transects. In relation to the statistical model, in this work a binomial model was used. On it, the response variable was defined as healthy/unhealthy, depending on the appearance of each tree. Akaike Information Criteria (AIC) was used to define the quality of the model. We selected model obtained a score of 89.68 and accounts for approximately 44% of data variability (D2 = 0,437). The main environmental variables that impact disease were: proximity to river course, topographic wetness index, cover of Daphne gnidium and Quercus ilex subsp. ballota, and the age of the individuals. Given the loss of Quercus forest mass caused by the spread of the oak decline disease, detected in several countries, including Spain, it becomes necessary to adequately understand the different factors that contribute and, in some cases, is the cause of the expansion of the disease, as well as to identify any inhibiting factors.

Effect of a Natural Brightener, Daphne gnidium L. on the Quality of Nickel Electroplating from Watts Bath

Daphne gnidium L. (DGL), a plant known to be rich source of polyphenols, a naturally occurring class of antioxidants, was tested for its ability to play the role of primary and secondary brighteners for electrodeposition of nickel, as a replacement for synthetic brighteners such as glycerol and formaldehyde. A simple and convenient approach was adapted consisting in adding an accurate amount of powdered leaves of Daphne gnidium L. (DGLP) or Daphne gnidium L. leaves extract (DGLE), to the Watts bath, to play the role of brightening agents. Cyclic voltammetry studies revealed that DGLP could inhibit the reaction of nickel reduction and improve the quality of the deposits as efficiently as glycerol and formaldehyde. SEM analyses showed that the micro-cracks decreased and sometimes disappeared from nickel deposits prepared in the presence of DGLP as a brightener. The results of this study show that DGL can be used satisfactorily, with minimum operations as a brightening agent for nickel electrodeposition. The key idea of direct immersion of DGLP in the Watts bath, aimed to the replacement of synthetic brighteners and the reduction of the overall cost of nickel electrodeposition.