Oil glands in the Neotropical genus Dahlstedtia Malme (Leguminosae, Papilionoideae, Millettieae)

Dahlstedtia pentaphylla (Taub.) Burkart and D. pinnata (Benth.) Malme belong to the Millettieae tribe and are tropical leguminous trees that produce a strong and unpleasant odour. In the present work, we investigated the distribution, development and histochemistry of foliar and floral secretory cavities that could potentially be related to this odour. The ultrastructure of foliar secretory cavities were also studied and compared with histochemical data. These data were compared with observations recorded for other species of Millettieae in order to gain a phylogenetic and taxonomic perspective. Foliar secretory cavities were only recorded for D. pentaphylla. Floral secretory cavities were present in the calyx, wings and keels in both species; in D. pinnata they also were found in bracteoles and vexillum. Such structures were found to originate through a schizogenous process. Epithelial cells revealed a large amount of flattened smooth endoplasmic reticula, well-developed dictyosomes and vacuoles containing myelin-like structures. Cavity lumen secretion stains strongly for lipids. Features of the secretory cavities studied through ultrastructural and histochemical procedures identify these structures as oil glands. Thus, if the odour produced by such plants has any connection with the accumulation of rotenone, as other species belonging to the "timbó" complex, the lipophilic contents of the secretory cavities of Dahlstedtia species take no part in such odour production. The presence, distribution patterns and frequencies of secretory structures in Dahlstedtia are taxonomically significant and may be utilized as a diagnostic character which justifies the separation of this genus into two species.

Chemical derivatization of galactoglucomannan for functional materials

In the framework of the biorefinery concept researchers aspire to optimize the utilization of plant materials, such as agricultural wastes and wood. For most of the known processes, the first steps in the valorisation of biomass are the extraction and purification of the individual components. The obtained raw products by means of a controlled separation can consecutively be modified to result in biofuels or biogas for energy production, but also in value-added products such as additives and important building blocks for the chemical and material industries. Considerable efforts are undertaken in order to substitute the use of oil-based starting materials or at least minimize their processing for the production of everyday goods. Wood is one of the raw materials, which have gained large attention in the last decades and its composition has been studied in detail. Nowadays, the extraction of water-soluble hemicelluloses from wood is well known and so for example xylan can be obtained from hardwoods and O-acetyl galactoglucomannans (GGMs) from softwoods. The aim of this work was to develop water-soluble amphiphilic materials of GGM and to assess their potential use as additives. Furthermore, GGM was also applied as a crosslinker in the synthesis of functional hydrogels for the removal of toxic metals and metalloid ions from aqueous solutions. The distinguished products were obtained by several chemical approaches and analysed by nuclear magnetic resonance spectroscopy (NMR), Fourier transform infrared spectroscopy (FTIR), size exclusion chromatography (SEC), thermal gravimetric analysis (TGA), scanning electron microscope SEM, among others. Bio-based surfactants were produced by applying GGM and different fatty acids as starting materials. On one hand, GGM-grafted-fatty acids were prepared by esterification and on the other hand, well-defined GGM-block-fatty acid derivatives were obtained by linking amino-functional fatty acids to the reducing end of GGM. The reaction conditions for the syntheses were optimized and the resultant amphiphilic GGM derivatives were evaluated concerning their ability to reduce the surface tension of water as surfactants. Furthermore, the block-structured derivatives were tested in respect to their applicability as additives for the surface modification of cellulosic materials. Besides the GGM surfactants with a bio-based hydrophilic and a bio-based hydrophobic part, also GGM block-structured derivatives with a synthetic hydrophobic tail, consisting of a polydimethylsiloxane chain, were prepared and assessed for the hydrophobization of surface of nanofibrillated cellulose films. In order to generate GGM block-structured derivatives containing a synthetic tail with distinguished physical and chemical properties, as well as a tailored chain length, a controlled polymerization method was used. Therefore, firstly an initiator group was introduced at the reducing end of the GGM and consecutively single electron transfer-living radical polymerization (SET-LRP) was performed by applying three different monomers in individual reactions. For the accomplishment of the synthesis and the analysis of the products, challenges related to the solubility of the reactants had to be overcome. Overall, a synthesis route for the production of GGM block-copolymers bearing different synthetic polymer chains was developed and several derivatives were obtained. Moreover, GGM with different molar masses were, after modification, used as a crosslinker in the synthesis of functional hydrogels. Hereby, a cationic monomer was used during the free radical polymerization and the resultant hydrogels were successfully tested for the removal of chromium and arsenic ions from aqueous solutions. The hydrogel synthesis was tailored and materials with distinguished physical properties, such as the swelling rate, were obtained after purification. The results generated in this work underline the potential of bio-based products and the urge to continue carrying out research in order to be able to use more green chemicals for the manufacturing of biorenewable and biodegradable daily products.

Susteinable steelmaking by process integration

Environmental issues, including global warming, have been serious challenges realized worldwide, and they have become particularly important for the iron and steel manufacturers during the last decades. Many sites has been shut down in developed countries due to environmental regulation and pollution prevention while a large number of production plants have been established in developing countries which has changed the economy of this business. Sustainable development is a concept, which today affects economic growth, environmental protection, and social progress in setting up the basis for future ecosystem. A sustainable headway may attempt to preserve natural resources, recycle and reuse materials, prevent pollution, enhance yield and increase profitability. To achieve these objectives numerous alternatives should be examined in the sustainable process design. Conventional engineering work cannot address all of these substitutes effectively and efficiently to find an optimal route of processing. A systematic framework is needed as a tool to guide designers to make decisions based on overall concepts of the system, identifying the key bottlenecks and opportunities, which lead to an optimal design and operation of the systems. Since the 1980s, researchers have made big efforts to develop tools for what today is referred to as Process Integration. Advanced mathematics has been used in simulation models to evaluate various available alternatives considering physical, economic and environmental constraints. Improvements on feed material and operation, competitive energy market, environmental restrictions and the role of Nordic steelworks as energy supplier (electricity and district heat) make a great motivation behind integration among industries toward more sustainable operation, which could increase the overall energy efficiency and decrease environmental impacts. In this study, through different steps a model is developed for primary steelmaking, with the Finnish steel sector as a reference, to evaluate future operation concepts of a steelmaking site regarding sustainability. The research started by potential study on increasing energy efficiency and carbon dioxide reduction due to integration of steelworks with chemical plants for possible utilization of available off-gases in the system as chemical products. These off-gases from blast furnace, basic oxygen furnace and coke oven furnace are mainly contained of carbon monoxide, carbon dioxide, hydrogen, nitrogen and partially methane (in coke oven gas) and have proportionally low heating value but are currently used as fuel within these industries. Nonlinear optimization technique is used to assess integration with methanol plant under novel blast furnace technologies and (partially) substitution of coal with other reducing agents and fuels such as heavy oil, natural gas and biomass in the system. Technical aspect of integration and its effect on blast furnace operation regardless of capital expenditure of new operational units are studied to evaluate feasibility of the idea behind the research. Later on the concept of polygeneration system added and a superstructure generated with alternative routes for off-gases pretreatment and further utilization on a polygeneration system producing electricity, district heat and methanol. (Vacuum) pressure swing adsorption, membrane technology and chemical absorption for gas separation; partial oxidation, carbon dioxide and steam methane reforming for methane gasification; gas and liquid phase methanol synthesis are the main alternative process units considered in the superstructure. Due to high degree of integration in process synthesis, and optimization techniques, equation oriented modeling is chosen as an alternative and effective strategy to previous sequential modelling for process analysis to investigate suggested superstructure. A mixed integer nonlinear programming is developed to study behavior of the integrated system under different economic and environmental scenarios. Net present value and specific carbon dioxide emission is taken to compare economic and environmental aspects of integrated system respectively for different fuel systems, alternative blast furnace reductants, implementation of new blast furnace technologies, and carbon dioxide emission penalties. Sensitivity analysis, carbon distribution and the effect of external seasonal energy demand is investigated with different optimization techniques. This tool can provide useful information concerning techno-environmental and economic aspects for decision-making and estimate optimal operational condition of current and future primary steelmaking under alternative scenarios. The results of the work have demonstrated that it is possible in the future to develop steelmaking towards more sustainable operation.

Antinociceptive effects of the essential oil of Croton zehntneri in mice

Croton zehntneri is an aromatic plant native to Northeastern Brazil, where it is often used in folk medicine. In the present study the antinociceptive effects of the essential oil of Croton zehntneri (EOCz) were evaluated in mice. EOCz administered orally at doses of 100 and 300 mg/kg reduced paw licking time in the second phase of the formalin test from the control value of 41.61 ± 8.62 to 12.01 ± 7.97 and 6.57 ± 3.42 s, respectively. During the first phase of the formalin test only 300 mg/kg induced a significant alteration (from 58.2 ± 7.02, control, to 28.7 ± 4.73 s). The number of contortions in response to intraperitoneal injections of acetic acid did not differ significantly between controls (80.6 ± 9.01) and experimental (300 mg/kg body weight) animals (89.1 ± 9.53% of the control numbers; P > or = 0.05, Student t-test). In the hot-plate test, EOCz at doses > or = 100 mg/kg significantly increased the latency time with respect to controls (11.2 ± 0.80). At 100 and 300 mg/kg this increase persisted for 180 and 240 min, respectively. The data show that EOCz is effective as an antinociceptive agent.

Antinociceptive effects of the essential oil of Croton nepetaefolius on mice

Croton nepetaefolius Baill., is an aromatic plant native to the northeast of Brazil where it is extensively used in folk medicine as a sedative, orexigen and antispasmodic agent. In the present study the antinociceptive effects of the essential oil of C. nepetaefolius (EOCn), administered orally, were evaluated in male Swiss mice (20-25 g). In the acetic acid-induced writhing test, EOCn (100 and 300 mg/kg; N = 14 and N = 12, respectively) was effective at the highest dose. In the hot-plate test, EOCn at 30 and 300 mg/kg, but not at 3 mg/kg, significantly increased the latency at all observation times up to the 180th min (N = 12 for each dose). In the formalin test, EOCn significantly reduced paw licking in the second phase of the test at 100 mg/kg (N = 12), but decreased it in both phases at 300 mg/kg (N = 12). At 30 mg/kg, the effect of EOCn did not differ from control values in either phase of the formalin test (N = 6). Pretreatment with naloxone (5 mg/kg, ip) significantly reversed the analgesic effect of morphine (5 mg/kg, sc) on both phases, but not that of EOCn at 300 mg/kg (N = 6) on both phases of the formalin test. The data show that orally administered EOCn promotes a dose-dependent antinociceptive effect whose mechanisms remain to be elucidated.

Antinociceptive properties of the essential oil of Ocimum gratissimum L. (Labiatae) in mice

We have investigated the antinociceptive effects of the essential oil of Ocimum gratissimum L. (Labiatae) (EOOG) in two classical models of pain in male Swiss mice (25-35 g), the writhing test and the formalin test. At doses of 30, 100 and 300 mg/kg (po), EOOG produced a dose-dependent inhibition (from 58.3 ± 4.4 to 40.7 ± 6.3, 36.4 ± 3.6 and 24.6 ± 3.6, respectively; N = 8-10, P<0.05) of acetic acid-induced writhing, causing up to a ~60% inhibition at the highest dose used, comparable to that obtained with indomethacin (10 mg/kg, po). At the same doses, EOOG predominantly inhibited the late (inflammatory) phase of the formalin-induced pain response (from 59.3 ± 8.3 to 40.4 ± 4.8, 23.2 ± 2.8 and 25.3 ± 5.5, respectively; N = 6, P<0.05), with a maximal reduction of ~60% of the control, although a significant reduction of the initial (neurogenic) phase was also observed at 300 mg/kg (from 62.5 ± 6.07 to 37 ± 5.9; P<0.05). On the basis of these data, we conclude that EOOG possesses interesting antinociceptive properties in the writhing and formalin tests. Due to the relatively low toxicity of EOOG, further detailed examination is strongly indicated for a better characterization of its pharmacological properties and its potential therapeutic value.

Silicon-containing species in used lube oil re-refining

Nowadays, the re-refining of the used lube oils has gained worldwide a lot of attention due to the necessity for added environmental protection and increasingly stringent environmental legislation. One of the parameters determining the quality of the produced base oils is the composition of feedstock. Estimation of the chemical composition of the used oil collected from several European locations showed that the hydrocarbon structure of the motor oil is changed insignificantly during its operation and the major part of the changes is accounted for with depleted oil additives. In the lube oil re-refining industry silicon, coming mainly from antifoaming agents, is recognized to be a contaminant generating undesired solid deposits in various locations in the re-refining units. In this thesis, a particular attention was paid to the mechanism of solid product formation during the alkali treatment process of silicon-containing used lube oils. The transformations of a model siloxane, tetramethyldisiloxane (TMDS), were studied in a batch reactor at industrially relevant alkali treatment conditions (low temperature, short reaction time) using different alkali agents. The reaction mechanism involving solid alkali metal silanolates was proposed. The experimental data obtained demonstrated that the solids were dominant products at low temperature and short reaction time. The liquid products in the low temperature reactions were represented mainly by linear siloxanes. The prolongation of reaction time resulted in reduction of solids, whereas both temperature and time increase led to dominance of cyclic products in the reaction mixture. Experiments with the varied reaction time demonstrated that the concentration of cyclic trimer being the dominant in the beginning of the reaction diminished with time, whereas the cyclic tetramer tended to increase. Experiments with lower sodium hydroxide concentration showed the same effect. In addition, a decrease of alkali agent concentration in the initial reaction mixture accelerated TMDS transformation reactions resulting in solely liquid cyclic siloxanes yields. Comparison of sodium and potassium hydroxides applied as an alkali agent demonstrated that potassium hydroxide was more efficient, since the activation energy in KOH presence was almost 2-fold lower than that for sodium hydroxide containing reaction mixture. Application of potassium hydroxide for TMDS transformation at 100° C with 3 hours reaction time resulted in 20 % decrease of solid yields compared to NaOH-containing mixture. Moreover, TMDS transformations in the presence of sodium silanolate applied as an alkali agent led to formation of only liquid products without formation of the undesired solids. On the basis of experimental data and the proposed reaction mechanism, a kinetic model was developed, which provided a satisfactory description of the experimental results. Suitability of the selected siloxane as a relevant model of industrial silicon-containing compounds was verified by investigation of the commercially available antifoam agent in base-catalyzed conditions.

Regime-Switching in the Impact of Oil Price Shocks on Stock Market Volatility: Evidence from Oil-Importing and Oil-Exporting Countries

Research has highlighted the adequacy of Markov regime-switching model to address dynamic behavior in long term stock market movements. Employing a purposed Extended regime-switching GARCH(1,1) model, this thesis further investigates the regime dependent nonlinear relationship between changes in oil price and stock market volatility in Saudi Arabia, Norway and Singapore for the period of 2001-2014. Market selection is prioritized to national dependency on oil export or import, which also rationalizes the fitness of implied bivariate volatility model. Among two regimes identified by the mean model, high stock market return-low volatility regime reflects the stable economic growth periods. The other regime characterized by low stock market return-high volatility coincides with episodes of recession and downturn. Moreover, results of volatility model provide the evidence that shocks in stock markets are less persistent during the high volatility regime. While accelerated oil price rises the stock market volatility during recessions, it reduces the stock market risk during normal growth periods in Singapore. In contrast, oil price showed no significant notable impact on stock market volatility of target oil-exporting countries in either of the volatility regime. In light to these results, international investors and policy makers could benefit the risk management in relation to oil price fluctuation.

Effect of chronic fish oil supplementation on renal function of normal and cachectic rats

In the present study we determined the effect of chronic diet supplementation with n-3 PUFA on renal function of healthy and cachectic subjects by providing fish oil (1 g/kg body weight) to female rats throughout pregnancy and lactation and then to their offspring post-weaning and examined its effect on renal function parameters during their adulthood. The animals were divided into four groups of 5-10 rats in each group: control, control supplemented with fish oil (P), cachectic Walker 256 tumor-bearing (W), and W supplemented with fish oil (WP). Food intake was significantly lower in the W group compared to control (12.66 ± 4.24 vs 25.30 ± 1.07 g/day). Treatment with fish oil significantly reversed this reduction (22.70 ± 2.94 g/day). Tumor growth rate was markedly reduced in the P group (16.41 ± 2.09 for WP vs 24.06 ± 2.64 g for W). WP group showed a significant increase in mean glomerular filtration rate compared to P and control (1.520 ± 0.214 ml min-1 kg body weight-1; P < 0.05). Tumor-bearing groups had low urine osmolality compared to control rats. The fractional sodium excretion decreased in the W group compared to control (0.43 ± 0.16 vs 2.99 ± 0.87%; P < 0.05), and partially recovered in the WP group (0.90 ± 0.20%). In summary, the chronic supplementation with fish oil used in this study increased the amount of fat in the diet by only 0.1%, but caused remarkable changes in tumor growth rate and cachexia, also showing a renoprotective function.

Effect of bullfrog (Rana catesbeiana) oil administered by gavage on the fatty acid composition and oxidative stress of mouse liver

The aim of the present study was to investigate the effects of daily intragastric administration of bullfrog oil (oleic, linoleic and palmitoleic acid-rich oil), corresponding to 0.4% of body weight for four weeks, on fatty acid composition and oxidative stress (lipid peroxidation and catalase activity) in mouse liver. The activities of aspartate aminotransferase (AST), alkaline phosphatase (ALP), alanine aminotransferase (ALT), and gamma-glutamyltransferase (GGT), biomarkers of tissue injury, were determined in liver homogenates and serum. The proportions of 18:2n-6, 20:4n-6, 20:5n-3, and 22:6n-3 (polyunsaturated fatty acids, from 37 to 60%) in the total fatty acid content were increased in the liver of the bullfrog oil-treated group (P < 0.05) compared to control. At the same time, a significant decrease in the relative abundance of 14:0, 16:0, and 18:0 (saturated fatty acids, from 49 to 25%) was observed. The hepatic content of thiobarbituric acid reactive substances (TBARS) was increased from 2.3 ± 0.2 to 12.3 ± 0.3 nmol TBA-MDA/mg protein and catalase activity was increased from 840 ± 32 to 1110 ± 45 µmol reduced H2O2 min-1 mg protein-1 in the treated group. Bullfrog oil administration increased AST and ALP activities in the liver (from 234.10 ± 0.12 to 342.84 ± 0.13 and 9.38 ± 0.60 to 20.06 ± 0.27 U/g, respectively) and in serum (from 95.41 ± 6.13 to 120.32 ± 3.15 and 234.75 ± 11.5 to 254.41 ± 2.73 U/l, respectively), suggesting that this treatment induced tissue damage. ALT activity was increased from 287.28 ± 0.29 to 315.98 ± 0.34 U/g in the liver but remained unchanged in serum, whereas the GGT activity was not affected by bullfrog oil treatment. Therefore, despite the interesting modulation of fatty acids by bullfrog oil, a possible therapeutic use requires care since some adverse effects were observed in liver.

Eucalyptol, an essential oil, reduces contractile activity in rat cardiac muscle

Eucalyptol is an essential oil that relaxes bronchial and vascular smooth muscle although its direct actions on isolated myocardium have not been reported. We investigated a putative negative inotropic effect of the oil on left ventricular papillary muscles from male Wistar rats weighing 250 to 300 g, as well as its effects on isometric force, rate of force development, time parameters, post-rest potentiation, positive inotropic interventions produced by Ca2+ and isoproterenol, and on tetanic tension. The effects of 0.3 mM eucalyptol on myosin ATPase activity were also investigated. Eucalyptol (0.003 to 0.3 mM) reduced isometric tension, the rate of force development and time parameters. The oil reduced the force developed by steady-state contractions (50% at 0.3 mM) but did not alter sarcoplasmic reticulum function or post-rest contractions and produced a progressive increase in relative potentiation. Increased extracellular Ca2+ concentration (0.62 to 5 mM) and isoproterenol (20 nM) administration counteracted the negative inotropic effects of the oil. The activity of the contractile machinery evaluated by tetanic force development was reduced by 30 to 50% but myosin ATPase activity was not affected by eucalyptol (0.3 mM), supporting the idea of a reduction of sarcolemmal Ca2+ influx. The present results suggest that eucalyptol depresses force development, probably acting as a calcium channel blocker.

Antimicrobial activity of the essential oil from Lippia sidoides, carvacrol and thymol against oral pathogens

Dental caries and periodontal disease are associated with oral pathogens. Several plant derivatives have been evaluated with respect to their antimicrobial effects against such pathogenic microorganisms. Lippia sidoides Cham (Verbenaceae), popularly known as "Alecrim-pimenta" is a typical shrub commonly found in the Northeast of Brazil. Many plant species belonging to the genus Lippia yield very fragrant essential oils of potential economic value which are used by the industry for the commercial production of perfumes, creams, lotions, and deodorants. Since the leaves of L. sidoides are also extensively used in popular medicine for the treatment of skin wounds and cuts, the objective of the present study was to evaluate the composition and antimicrobial activity of L. sidoides essential oil. The essential oil was obtained by hydro-distillation and analyzed by GC-MS. Twelve compounds were characterized, having as major constituents thymol (56.7%) and carvacrol (16.7%). The antimicrobial activity of the oil and the major components was tested against cariogenic bacterial species of the genus Streptococcus as well as Candida albicans using the broth dilution and disk diffusion assays. The essential oil and its major components thymol and carvacrol exhibited potent antimicrobial activity against the organisms tested with minimum inhibitory concentrations ranging from 0.625 to 10.0 mg/mL. The most sensitive microorganisms were C. albicans and Streptococcus mutans. The essential oil of L. sidoides and its major components exert promising antimicrobial effects against oral pathogens and suggest its likely usefulness to combat oral microbial growth.

Cytotoxic effect of essential oil of thyme (Thymus broussonettii) on the IGR-OV1 tumor cells resistant to chemotherapy

The anti-tumor effect of the Moroccan endemic thyme (Thymus broussonettii) essential oil (EOT) was investigated in vitro using the human ovarian adenocarcinoma IGR-OV1 parental cell line OV1/P and its chemoresistant counterparts OV1/adriamycin (OV1/ADR), OV1/vincristine (OV1/VCR), and OV1/cisplatin (OV1/CDDP). All of these cell lines elicited various degrees of sensitivity to the cytotoxic effect of EOT. The IC50 values (mean ± SEM, v/v) were 0.40 ± 0.02, 0.39 ± 0.02, 0.94 ± 0.05, and 0.65 ± 0.03% for OV1/P, OV1/ADR, OV1/VCR, and OV1/CDDP, respectively. Using the DBA-2/P815 (H2d) mouse model, tumors were developed by subcutaneous grafting of tumor fragments of similar size obtained from P815 (murin mastocytoma cell line) injected in donor mouse. Interestingly, intra-tumoral injection of EOT significantly reduced solid tumor development. Indeed, by the 30th day of repeated EOT treatment, the tumor volumes of the animals were 2.00 ± 0.27, 1.35 ± 0.20, and 0.85 ± 0.18 cm³ after injection with 10, 30, or 50 µL per 72 h (six times), respectively, as opposed to 3.88 ± 0.50 cm³ for the control animals. This tumoricidal effect was associated with a marked decrease of mouse mortality. In fact, in these groups of mice, the recorded mortality by the 30th day of treatment was 30 ± 4, 18 ± 4, and 8 ± 3%, respectively, while the control animals showed 75 ± 10% of mortality. These data indicate that the EOT which contains carvacrol as the major component has an important in vitro cytotoxic activity against tumor cells resistant to chemotherapy as well as a significant antitumor effect in mice. However, our data do not distinguish between carvacrol and the other components of EOT as the active factor.

Antinociceptive effects of the essential oil of Mentha x villosa leaf and its major constituent piperitenone oxide in mice

Mentha x villosa Huds (Labiatae) is an aromatic herb widely used in folk medicine. Since the essential oil of the herb has many pharmacological activities, including antispasmodic effects, we determined whether the oil and its major constituent, piperitenone oxide (PO), have antinociceptive activity. The essential oil of M. x villosa (EOMV) and PO administered orally at 200 mg/kg (vehicle: 0.1% Tween 80 in water) significantly reduced the writhings induced by acetic acid from control values of 59.5 ± 3.1 s (N = 10) to 31.9 ± 2.8 s (N = 10) and 23.8 ± 3.4 s (N = 10), respectively. When administered at 100 and 200 mg/kg, EOMV reduced the paw licking time for the second phase of the formalin test from the control value of 20.6 ± 2.1 s (N = 13) to 5.3 ± 2.2 s (N = 12) and 2.7 ± 1.2 s (N = 18), respectively. At 100 and 200 mg/kg, PO reduced this second phase to 8.3 ± 2.7 s (N = 12) and 3.0 ± 1.2 s (N = 10), respectively. This effect of EOMV and PO was not reversed by naloxone. EOMV and PO had no significant effect on the first phase of the formalin test. As evaluated by the hot-plate and tail immersion test, EOMV and PO, at doses up to 200 mg/kg, showed no analgesic activity. These results show that EOMV and PO have antinociceptive activity and suggest that this effect is probably an indirect anti-inflammatory effect, which does not involve the central nervous system.

Fish oil ingestion reduces the number of aberrant crypt foci and adenoma in 1,2-dimethylhydrazine-induced colon cancer in rats

We determined the effect of fish oil (FO) ingestion on colonic carcinogenesis in rats. Male Wistar rats received 4 subcutaneous injections (40 mg/kg body weight each) of 1,2-dimethylhydrazine (DMH) at 3-day intervals and were fed a diet containing 18% by weight FO (N = 10) or soybean oil (SO, N = 10) for 36 weeks. At sacrifice, the colon was removed, aberrant crypt foci were counted and the fatty acid profile was determined. Intestinal tumors were removed and classified as adenoma or carcinoma. Liver and feces were collected and analyzed for fatty acid profile. FO reduced the mean (± SEM) number of aberrant crypt foci compared to SO (113.55 ± 6.97 vs 214.60 ± 18.61; P < 0.05) and the incidence of adenoma (FO: 20% vs SO: 100%), but carcinoma occurred equally in FO and SO rats (2 animals per group). The polyunsaturated fatty acid (PUFA) profile of the colon was affected by diet (P < 0.05): total ω-3 (FO: 8.18 ± 0.97 vs SO: 1.71 ± 0.54%) and total ω-6 (FO: 3.83 ± 0.59 vs SO: 10.43 ± 1.28%). The same occurred in the liver (P < 0.05): total ω-3 (FO: 34.41 ± 2.6 vs SO: 6.46 ± 0.59%) and total ω-6 (FO: 8.73 ± 1.37 vs SO: 42.12 ± 2.33%). The PUFA profile of the feces and liver polyamine levels did not differ between groups (P > 0.05). In conclusion, our findings indicate that chronic FO ingestion protected against the DMH-induced preneoplastic colon lesions and adenoma development, but not against carcinoma in rats.