Poliuretanos obtenidos a partir de aceite de higuerilla modificado y poli-isocianatos de lisina: síntesis, propiedades mecánicas y térmicas y degradación in vitro

Biodegradable polyurethanes (PUR) were prepared from polyols derived from castor oil by transesterification of pentaerythritol-modified castor oil and lysine polyisocyanates (LDI and LTI). The polyurethanes obtained were characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis (TGA), and dynamic mechanical thermal analysis (DMTA). The mechanical behavior of the polyurethanes was measured by Shore A hardness and tensile testing (stress-strain curves). The biodegradable nature of the material was determined by contact angle, water absorption tests, and in vitro degradation in PBS solution. This study aims to examine the effect of the structure and functionality of diisocyanate on the mechanical properties and in vitro degradation of the material. The results were compared with homologous materials obtained from isophorone diisocyanate (IPDI) used in previous works. The objective was to evaluate candidate materials that can be potentially used in tissue engineering.

Spontaneous poisoning by Ricinus communis (Euphorbiaceae) in cattle

The aim of this study is to report cases of spontaneous poisoning of cattle by Ricinus communis (castor beans) in Paraíba, a semiarid region of northeastern Brazil. The cases were observed in 2 herds on neighboring properties in 2013. Clinical signs developed within 6-24 h and consisted of weakness, tachycardia, dyspnea, profuse watery diarrhea, dehydration, depression, instability, cramps, permanent lateral recumbency and death within 48-72 h. Of the 60 cattle at risk, 19 were affected and 14 died. Five fully recovered after the course of 12 days. Three animals were necropsied. The main gross lesions were hemopericardium, hemothorax, pulmonary edema, petechial hemorrhages in the epicardium and endocardium, ecchymoses at the papillary muscles and suffusions on the intercostal muscles. Hemorrhages were also observed in the abdominal cavity, spleen and mucosa of the abomasum and small intestine. The rumen content was liquid with a large amount of castor bean seeds. There were circular, whitish and focally diffuse areas in the liver parenchyma. The main microscopic lesions consisted of multifocal coagulative myocardial necrosis with the presence of mononuclear cell infiltration and varying degrees of bleeding between cardiac muscle fibers. The abomasum and small intestine mucosae and submucosa had mild edema and mononuclear and polymorphonuclear inflammatory cell infiltration. The diagnosis of R. communis was based on the history of plant consumption, clinical signs, pathology of the disease and the presence of large amounts of castor bean seeds in the forestomachs.

Antinociceptive effects of Cremophor EL orally administered to mice

Surfactants are frequently used to improve solubilization of lipophilic drugs. Cremophor EL (CrEL) is a polyoxyethylated castor oil surfactant used to solubilize water-insoluble drugs such as anesthetic, antineoplastic, immunosuppressive and analgesic drugs, vitamins and new synthetic compounds, including potential analgesics. The antinociceptive effect of CrEL (3.2, 6.4 and 10.6 g/kg, in 10 ml/kg body weight, by gavage) on the abdominal writhing response induced by intraperitoneal administration of acetic acid (0.8%, 10 ml/kg body weight) and on the tail immersion test was investigated in mice. Control animals received castor oil (10 ml/kg body weight) or saline (0.9% NaCl, 10 ml/kg body weight). CrEL reduced nociception in a dose-dependent manner in both tests. At 10.6 g/kg, CrEL caused antinociception similar to that induced by dipyrone (300 mg/kg, by gavage) in the abdominal writhing test, and antinociception similar to that induced by morphine (20 mg/kg, by gavage) in the tail immersion test. The effect of castor oil was similar to that of saline in both assays. These data indicate that the appropriate controls should be used when evaluating the effects of potential antinociceptive agents dissolved in CrEL.

Effect of (-)-∆9-tetrahydrocannabinoid on the hepatic redox state of mice

(-)-∆9-Tetrahydrocannabinol (∆9-THC), a psychoactive component of marijuana, has been reported to induce oxidative damage in vivo and in vitro. In this study, we administered ∆9-THC to healthy C57BL/6J mice aged 15 weeks in order to determine its effect on hepatic redox state. Mice were divided into 3 groups: ∆9-THC (N = 10), treated with 10 mg/kg body weight ∆9-THC daily; VCtrl (N = 10), treated with vehicle [1:1:18, cremophor EL® (polyoxyl 35 castor oil)/ethanol/saline]; Ctrl (N = 10), treated with saline. Animals were injected ip twice a day with 5 mg/kg body weight for 10 days. Lipid peroxidation, protein carbonylation and DNA oxidation were used as biomarkers of oxidative stress. The endogenous antioxidant defenses analyzed were glutathione (GSH) levels as well as enzyme activities of superoxide dismutase, catalase, glutathione S-transferase, glutathione reductase, and glutathione peroxidase (GPx) in liver homogenates. The levels of mRNA of the cannabinoid receptors CB1 and CB2 were also monitored. Treatment with ∆9-THC did not produce significant changes in oxidative stress markers or in mRNA levels of CB1 and CB2 receptors in the liver of mice, but attenuated the increase in the selenium-dependent GPx activity (Δ9-THC: 8%; VCtrl: 23% increase) and the GSH/oxidized GSH ratio (Δ9-THC: 61%; VCtrl: 96% increase), caused by treatment with the vehicle. Δ9-THC administration did not show any harmful effects on lipid peroxidation, protein carboxylation or DNA oxidation in the healthy liver of mice but attenuated unexpected effects produced by the vehicle containing ethanol/cremophor EL®.

Head Space Solid Phase Micro-Extraction (HS - SPME) of volatile organic compounds produced by Sporidiobolus salmonicolor (CBS 2636)

The aim of the present study was the assessment of volatile organic compounds produced by Sporidiobolus salmonicolor (CBS 2636) using methyl and ethyl ricinoleate, ricinoleic acid and castor oil as precursors. The analysis of the volatile organic compounds was carried out using Head Space Solid Phase Micro-Extraction (HS - SPME). Factorial experimental design was used for investigating extraction conditions, verifying stirring rate (0-400 rpm), temperature (25-60 ºC), extraction time (10-30 minutes), and sample volume (2-3 mL). The identification of volatile organic compounds was carried out by Gas Chromatography with Mass Spectrum Detector (GC/MSD). The conditions that resulted in maximum extraction were: 60 ºC, 10 minutes extraction, no stirring, sample volume of 2.0 mL, and addition of saturated KCl (1:10 v/v). In the bio-production of volatile organic compounds the effect of stirring rate (120-200 rpm), temperature (23-33 ºC), pH (4.0-8.0), precursor concentration (0.02-0.1%), mannitol (0-6%), and asparagine concentration (0-0.2%) was investigated. The bio-production at 28 ºC, 160 rpm, pH 6,0 and with the addition of 0.02% ricinoleic acid to the medium yielded the highest production of VOCs, identified as 1,4-butanediol, 1,2,2-trimethylciclopropilamine, beta-ionone; 2,3-butanodione, pentanal, tetradecane, 2-isononenal, 4-octen-3-one, propanoic acid, and octadecane.

Larvicidal activity of oil-resin fractions from the Brazilian medicinal plant Copaifera reticulata Ducke (Leguminosae-Caesalpinoideae) against Aedes aegypti (Diptera, Culicidae)

Oil-resin fractions from Copaifera reticulata Ducke (Leguminosae-Caesalpinoideae) were evaluated for larvicidal activity on third larval instars of Aedes aegypti, in searching for alternative control methods for this mosquito. The bioactive fractions were chemically monitored by thin-layer chromatography, ¹H and 13C nuclear magnetic resonance and mass spectrometry. Bioassays were performed using five repetitions, at a temperature of 28 ± 1°C, relative humidity of 80 ± 5% and light and dark cycles of 12h. Mortality was indicated by darkening of the cephalic capsule after 24h of exposure of the larvae to the solutions. The most active fractions were CRM1-4 (sesquiterpenes) and CRM5-7 (labdane diterpenes), which showed LC50 values of 0.2 and 0.8ppm, respectively.

Potential of biologically active plant oils to control mosquito larvae (Culex pipiens, Diptera: Culicidae) from an egyptian locality

The insecticidal effect of six commercially available plant oils was tested against 4th larval instars of Culex pipiens. Larvae were originally collected from Meit El-Attar, Qalyubia Governorate, Egypt, and then reared in the laboratory until F1 generation. The LC50 values were 32.42, 47.17, 71.37, 83.36, 86.06, and 152.94 ppm for fenugreek (Trigonella foenum-grecum), earth almond (Cyperus esculentus), mustard (Brassica compestris), olibanum (Boswellia serrata), rocket (Eruca sativa), and parsley (Carum ptroselinum), respectively. The tested oils altered some biological aspects of C. pipiens, for instance, developmental periods, pupation rates, and adult emergences. The lowest concentrations of olibanum and fenugreek oils caused remarkable prolongation of larval and pupal durations. Data also showed that the increase of concentrations was directly proportional to reduction in pupation rates and adult emergences. Remarkable decrease in pupation rate was achieved by mustard oil at 1000 ppm. Adult emergence was suppressed by earth almond and fenugreek oils at 25 ppm. In addition, the tested plant oils exhibited various morphological abnormalities on larvae, pupae, and adult stages. Consequently, fenugreek was the most potent oil and the major cause of malformation of both larval and pupal stages. Potency of the applied plant oils provided an excellent potential for controlling C. pipiens.

Bioactivity of plant extracts on the larval and pupal stages of Aedes aegypti (Diptera, Culicidea)

Introduction Aedes aegypti is responsible for the transmission of the dengue and yellow fever viruses. This study evaluated the effects of extracts from Cnidosculos phyllacanthus, Ricinus communis, and Coutarea hexandra on the developmental periods of A.aegypti larvae and pupae. Crude extracts of C. phyllacanthus and C. hexandra and oil from R. communis and C. phyllacanthus were used. Methods Bioassays of the larvicidal and pupicidal effects of these products at different concentrations and times of exposure were evaluated. The lethal and sublethal effects were determined using different concentrations in larvicidal tests. Mortality data were evaluated by Probit analysis to determine the LC50 and LC90 values. Results The vegetable oils from C. phyllacanthus and R. communis demonstrated greater efficiency for larval control with an LC50=0.28µl/mL and an LC90=1.48µl/mL and LC50=0.029µl/mL and a LC90=0.26µl/mL, respectively. In pupal tests toxic effects for all insects were verified after exposure to the products at significant LC50 and LC90 values for 24 and 48h. The effects of sublethal concentrations of C. phyllacanthus (oil) were more effective on the insects. Conclusions The vegetables oils from C. phyllacanthus and R. communis demonstrated greater potential from the control of different developmental periods in the life cycle of this insect.

Cytotoxic evaluation of essential oil from Zanthoxylum rhoifolium Lam. leaves

Zanthoxylum rhoifolium Lam is a plant popularly used as antimicrobial, for malaria and inflammatory treatment. The essential oil of Z. rhoifolium was extracted and its cytotoxic effects against HeLa (human cervical carcinoma), A-549 (human lung carcinoma), HT-29 (human colon adenocarcinoma), Vero (monkey kidney) cell lines and mice macrophages were evaluated. Some of the terpenes of its essential oil (ß-caryophyllene, alpha-humulene, alpha -pinene, myrcene and linalool) were also tested to verify their possible influence in the oil cytotoxic activity. The results obtained permitted to confirm that the essential oil is cytotoxic against tumoral cells (CD50 = 82.3, 90.7 and 113.6 µg/ml for A-549, HeLa e HT-29 cell lines, respectively), while it did not show cytotoxicity against non-tumoral cells (Vero and mice macrophages). Thus, the essential oil from Z. rhoifolium leaves seems to present a possible therapeuthic role due to its selective cytotoxic activity against tumoral cell lines.

Biomass production and essential oil yield from leaves, fine stems and resprouts using pruning the crown of Aniba canelilla (H.B.K.) (Lauraceae) in the Central Amazon

Aniba canelilla (H.B.K.) Mez. is a tree species from Amazon that produces essential oil. The oil extraction from its leaves and stems can be an alternative way to avoid the tree cutting for production of essential oil. The aim of this study was to analyse factors that may influence the essential oil production and the biomass of resprouts after pruning the leaves and stems of A. canelilla trees. The tree crowns were pruned in the wet season and after nine months the leaves and stems of the remaining crown and the resprouts were collected, in the dry season. The results showed that the essential oil yield and chemical composition differed among the stems, leaves and resprouts. The stems' essential oil production differed between the seasons and had a higher production in the resprouting stems than the old stems of the remaining crown. The production of essential oil and leaf biomass of resprouts were differently related to the canopy openness, indicating that light increases the production of the essential oil and decreases the biomass of resprouting leaves. This study revealed that plant organs differ in their essential oil production and that the canopy openness must be taken into account when pruning the A. canelilla tree crown in order to achieve higher oil productivity.

Tocopherol profile of Brazil nut oil from different geographic areas of the Amazon region

The tocopherol content of Brazil nut oil from different Amazon regions (Manicoré-AM, Rio Preto da Eva-AM, São João da Baliza-RR, Caroebe-RR, Belém-PA, and Xapurí-AC) was investigated by normal-phase high-performance liquid chromatography. For all authentic oils, two isomers: α- and γ-tocopherols were observed (37.92-74.48 µg g-1, 106.88-171.80 µg g-1, respectively), and their levels were relatively constant among the oils having these geographic origins, which would enable to distinguish Brazil nut oil from other plant oils for authentication purposes. Commercial Brazil nut oils were also evaluated, and some of these oils demonstrated a tocopherol content that was very different from that of the authentic oils. Therefore, we suggest that the tocopherol profile of Brazil nut oil can be useful chemical marker for quality control and authentication.

The effect of sub-lethal doses of Azadirachta indica (Meliaceae) oil on the midgut of Spodoptera frugiperda (Lepidoptera, Noctuidae)

The fall armyworm, Spodoptera frugiperda, is one of the major field pests for maize production. It is mainly controlled by means of synthetic, and more recently by resistant cultivar of maize expressing Bt toxins. The neem tree, Azadirachta indica, is a plant that can potentially control insects with the advantage of being food and environmental safe. The aim of this study was to assess the effect of neem oil on the development and survival of S. frugiperda caterpillars by assessing histological alterations caused on their midgut. Newly hatched caterpillars were submitted to three neem oil concentrations: 0.006; 0.05; 0.4%, which were added to their artificial diet. Ten 3rd instar caterpillars, taken from each treatment, were submitted to histological analysis. The alimentary canals from the specimens were fixed in Baker for 12 hours, desiccated and diaphanized in alcohol/xylol (1:1) and xylol. After placing the samples in paraffin, they were sliced in 8 µm sections and stained with hematoxylin-eosin stain. The neem oil added to the diet of S. frugiperda caused total mortality at dose of 0.4% whilst still in the first instars, prolonged the larval and pupal stages, and reduced the pupal weight. Histo-physiological alterations such as degeneration of the epithelial lining of the midgut and in the peritrophic matrix were found at all concentrations of neem oil.

Toxic effects of essential plant oils in adult Sitophilus oryzae (Linnaeus) (Coleoptera, Curculionidae)

Toxic effects of essential plant oils in adult Sitophilus oryzae (Linnaeus) (Coleoptera, Curculionidae). Stored grains are subject to losses in quality nutritional value and in sanitation from the time they are stored to the time they are consumed. Botanical insecticides may offer an alternative solution for pest control. The objective was to test the insecticidal properties of the essential oils of Cymbopogon citratus (leaf), Zingiber officinale (root) and Mentha sp. (leaf). The efficacy of these oils was tested to control the rice weevil, S. oryzae, using hydrodistillation. Chemical analysis of the essential oils was carried out by gas chromatography. Major components of C. citratus were geranial (48%) and neral (31%), of Z. officinale were α-zingibereno (13%), geranial (16%), neral (10%) and α-farneseno (5%) and of Mentha sp. was menthol (92%). Bioassays were carried out by fumigation and topical application. In topical application assays, the essential oil of C. citratus had greater toxicity (LC50 0.027 µL mL-1) and shorter exposure time than the oils of the other two plants. After 24 h and 48 h, 70% and 100% mortality of S. oryzae occurred, respectively. In fumigation assays, essential oil of Z. officinale had a lower LC50 (1.18 µL cm-2) and 70% mortality after 24 h exposure. Therefore, we recommend the use of essential oils of C. citratus and Z. officinale to control the rice weevil S. oryzae.

Nutrient extraction and exportation by castor bean hybrid lyra

Information about nutrient extraction and exportation by crops, as well as the periods of highest nutrient demand is important for an adequate fertilization management. However, there are no studies on the nutrient uptake of short-stature hybrid castor bean. Therefore, the purpose of this study was to evaluate nutrient extraction and exportation by short-stature castor bean hybrid Lyra, in the spring-summer and fall-winter growing seasons. The experiments were conducted in the 2005/2006 spring-summer and 2006 fall-winter growing seasons on an Oxisol, in Botucatu, SP, in a randomized block design, with four replications. The plots consisted of plant samplings, which occurred 17, 31, 45, 59, 73, 97 and 120 days after emergence (DAE) in the spring-summer and 17, 31, 45, 59, 80, 100 and 120 DAE in fall-winter growing season. The growth of hybrid Lyra was slow and nutrient uptake lowest between emergence and the beginning of flowering. The period of highest dry matter (DM) accumulation rates and highest nutrient demand were observed 40 to 80 DAE, in both growing seasons. The order of nutrient extraction by the plants in the spring-summer growing season was: N>K>Ca>Mg>S>P>Fe>Mn>Zn>B>Cu>Mo. In fall-winter, S was more absorbed than Mg. Seed yield was higher in the spring-summer (2.995 kg ha-1), but nutrient extraction and exportation per ton of seed were similar in both growing seasons. Around 58 % of N and 84 % of P, and approximately half of the S and B absorbed throughout the cycle were exported with the seeds. However, most of the other nutrients accumulated in the plants returned to the soil in plant residues.

Deficiency symptoms and uptake of micronutrients by castor bean grown in nutrient solution

Castor bean is a nutrient-demanding species, but there is still little information on its micronutrient requirements. The objectives of this study were to evaluate the effects of levels of B (2.5, 12.5 and 25.0 µmol L-1), Cu (0.05, 0.25 and 0.50 µmol L-1), Mn (0.2, 1.0 and 2.0 µmol L-1) and Zn (0.2, 1.0 and 2.0 µmol L-1) in a nutrient solution on plant B, Cu, Mn and Zn concentrations and uptake, vegetative growth and fruit yield of castor bean "Iris", grown in greenhouse. The experiment was arranged in a completely randomized block design with three replicates. The first deficiency symptoms were observed for B, followed by Zn, Cu and Mn. The main changes in the cell ultrastructure due to lack of B were thickening of the cell walls and middle lamellae, distorted chloroplasts and tightly stacked thylakoids, besides the absence of starch grains. The Mn, Zn and Cu deficiencies led to disruption of chloroplasts, disintegration of thylakoids and absence of amyloplasts. The concentration and uptake of B, Cu, Mn, and Zn in castor bean plants increased with micronutrient supply in the solution. Fruit yield was drastically reduced by B and Mn deficiencies. On the other hand, the dry matter yield of the shoot and root of castor bean plants was not. In the treatment with full nutrient solution, the leaves accumulated 56 and 48 % of the total B and Mn taken up by the plants, respectively, and the seeds and roots 85 and 61 % of the total Cu and Zn taken up, respectively. This shows the high demand of castor bean Iris for B and Mn for fruit yield.