Effects of n-3 polyunsaturated fatty acids and vitamin E on colonic mucosal leukotriene generation, lipid peroxidation, and microcirculation in rats with experimental colitis

Protective Effect of Diet-Supplemented and Endogenously Produced Omega-3 Fatty Acids against HFD-Induced Colon Inflammation in Mice

Perilla (Perilla frutescens) oil reduces high-fat-diet-induced colon inflammation by suppressing the NF-κB pathway. In the current study, we compared the effect of endogenously produced and externally supplemented omega-3 fatty acids on high-fat-diet-induced colon inflammation. The fat-1 transgenic mice that endogenously synthesize omega-3 fatty acids were backcrossed with C57BL/6J wild-type mice to obtain transgenic (TR) and wild-type (WT) littermates. Five-week-old male littermates were divided into five groups: two groups fed 10% normal diet (WTLD, TRLD) and three groups fed with a 60% fat high-fat diet (WTHD, TRHD, and WTPO). In the WTPO group, 8% (w/w) of perilla oil was added. Perilla oil supplemented WT mice and fat-1 transgenic mice suppressed high-fat-diet-induced body weight and improved serum lipid levels. Furthermore, the WTPO and TRHD groups exhibited increased colon length, lower macroscopic scores, and reduced levels of pro-inflammatory markers and improved epithelial integrity barrier markers. The expression of GPR120 was increased in the WTPO group. Altogether, our results indicated that perilla oil could improve the symptoms of colon inflammation as an alternate omega-3 fatty acid supplement.

Perilla Fruit Oil-Fortified Soybean Milk Intake Alters Levels of Serum Triglycerides and Antioxidant Status, and Influences Phagocytotic Activity among Healthy Subjects: A Randomized Placebo-Controlled Trial

This study aimed to develop perilla fruit oil (PFO)-fortified soybean milk (PFO-SM), identify its sensory acceptability, and evaluate its health outcomes. Our PFO-SM product was pasteurized, analyzed for its nutritional value, and had its acceptability assessed by an experienced and trained descriptive panel (n = 100) based on a relevant set of sensory attributes. A randomized clinical trial was conducted involving healthy subjects who were assigned to consume deionized water (DI), SM, PFO-SM, or black sesame-soybean milk (BS-SM) (n = 48 each, 180 mL/serving) daily for 30 d. Accordingly, health indices and analyzed blood biomarkers were recorded. Consequently, 1% PFO-SM (1.26 mg ALA rich) was generally associated with very high scores for overall acceptance, color, flavor, odor, taste, texture, and sweetness. We observed that PFO-SM lowered levels of serum triglycerides and erythrocyte reactive oxygen species, but increased phagocytosis and serum antioxidant activity (p < 0.05) when compared to SM and BS-SM. These findings indicate that PFO supplementation in soybean milk could enhance radical-scavenging and phagocytotic abilities in the blood of healthy persons. In this regard, it was determined to be more efficient than black sesame supplementation. We are now better positioned to recommend the consumption of PFO-SM drink for the reduction of many chronic diseases. Randomized clinical trial registration (Reference number 41389) by IRSCTN Registry.

Hair Growth Promotion with Black Soybean Extracts: case series

Black soybean (BS) is widely thought to prevent or alleviate hair loss, which has been demonstrated by in vitro experiments. However, few clinical studies have directly assessed the effect of BS on hair growth. To assess the safety and efficacy of BS, we administered BS extract to 10 adult patients for 3 months without any other hair products and treatments. The number and diameter of hair lost from washing were examined every 4 weeks. In addition, the participants’ satisfaction with their hair condition was also measured using the VAS (1 to 10) before and after treatment. The mean number of lost hair was 140.7 (SD 59.4) at baseline and 38.8 (SD 54.4) after 12 weeks, and the diameter of lost hair was 72.4 µm (SD 11.9) at baseline and 80.4 µm (SD 8.8) after 12 weeks, which indicated a statistically significant improvement (p = 0.002, p = 0.022, paired t-test). The satisfaction score was significantly increased from 6.10 (SD 1.2) to 8.2 (SD 1.1) after 12 weeks. These results suggest that BS extract may promote hair growth and prevent hair loss.

Pistacia Atlantica Desf., a Source of Healthy Vegetable Oil

Pistacia atlantica, which belongs to the Anacardiaceae family, is an important species for rural people in arid and semi-arid areas. The fruit, rich in oil, is used in traditional medicine for the treatment of various diseases. The oil extracted from this species growing in a northern area of Algeria and its fatty acid composition were previously studied. However, the largest areas where this species is present (traditional cultivation) is located in southern Algeria. Moreover, studies on oil fatty acid composition and essential oil were always conducted separately. This study was performed in order to assess the fatty acid and volatile organic compound composition of P. atlantica vegetable oil. The seeds were collected randomly from Djelfa (300 km South of Algiers, Algeria). Oil content and fatty acid composition were determined by Soxhlet extraction. The seeds contained high concentrations of oil (32–67%). The major fatty acids were oleic (39–49%), linoleic (23.6–31%), and palmitic (21.3–26.6%) acids. The ratio of polyunsaturated fatty acids (PUFA) to saturated fatty acids (SFA) indicated that the content of unsaturated fatty acids was approximately three times higher than that of SFA. This ratio is widely used in epidemiological studies and research on cardiovascular diseases, diabetes, and metabolic syndrome. The ratios of -acids, i.e., -9/-6 and -6/-3, were 1.3–2 and 18.5–38.3, respectively. Crushed seeds were analyzed by headspace solid-phase microextraction (SPME) coupled with gas chromatography–mass spectrometry. More than 40 compounds were identified, mainly monoterpenes (C10H16), such as α-terpinene and terpinolene, but also sesquiterpenes (C15H24) at lower levels. The value of this species as a source of healthy oil rich in -3 acid and its effects on cardiovascular disease risk are discussed.

Comparative effects of plant oils and trans-fat on blood lipid profiles and ischemic stroke in rats

Since plant oils are believed to be better than animal fats for cerebrovascular and cardiovascular diseases, the effects of various plant oils and trans-fat on blood lipid profiles and ischemic stroke were investigated. Sprague-Dawley rats were fed a diet containing the oils or trans-fat, and then body weights, blood lipids, and effects on brain infarction and physical dysfunction induced by middle cerebral artery occlusion (MCAO) were analyzed. All the oils and trans-fat, except perilla oil, significantly increased body fats and body weight gain. Sesame oil and trans-fat specifically increased blood cholesterols and triglycerides, respectively, while perilla oil decreased both cholesterols and triglycerides. Perilla oil not only attenuated cerebral infarction, but also restored locomotor activity and rota-rod performances of MCAO rats. It is suggested that perilla oil among oils and fats could be the first choice to reduce the risk of metabolic syndrome and ischemic stroke.

Anti-atherosclerotic effects of perilla oil in rabbits fed a high-cholesterol diet

Anti-atherosclerosis effects of perilla oil were investigated, in comparison with lovastatin, in rabbits fed a high-cholesterol diet (HCD). Hypercholesterolemia was induced in rabbits by feeding the HCD containing 0.5% cholesterol and 1% corn oil, and perilla oil (0.1 or 0.3%) was added to the diet containing 0.5% cholesterol for 10 weeks. HCD greatly increased blood total cholesterol and low-density lipoproteins, and caused thick atheromatous plaques, covering 74% of the aortic wall. Hyper-cholesterolemia also induced lipid accumulation in the liver and kidneys, leading to lipid peroxidation. Perilla oil not only attenuated hypercholesterolemia and atheroma formation, but also reduced fat accumulation and lipid peroxidation in hepatic and renal tissues. The results indicate that perilla oil prevents atherosclerosis and fatty liver by controlling lipid metabolism, and that it could be the first choice oil to improve diet-induced metabolic syndrome.

Treatment with Mesna and n-3 polyunsaturated fatty acids ameliorates experimental ulcerative colitis in rats

Oxidative damage is a central feature of ulcerative colitis. Here, we tested whether the antioxidant Mesna, when administered alone or in combination with n-3 polyunsaturated fatty acids (n-3 PUFAs), affects the outcome of dextran sodium sulphate (DSS)-induced ulcerative colitis in rats. After the induction of colitis, DSS-treated rats were further treated orally (p.o), intraperitoneally (i.p) or intrarectally (i.r) for either 7 or 14 days with Mesna, n-3 PUFAs or both. Rats were euthanized at the end of each treatment period. Clinical disease activity index was recorded throughout the experiment. At necropsy colorectal gross lesions were scored. Colitis was scored histologically, and the expression of myeloperoxidase (MPO), caspase-3, inducible nitric oxide synthase (iNOS) and nuclear factor κB (NF-κΒ) in colonic tissue was assessed by immunohistochemistry. Mesna alone was sufficient to significantly reduce colorectal tissue damage when administered orally or intraperitoneally. Orally coadministered n-3 PUFAs enhanced this effect, resulting in the significant suppression of DSS colitis after 7 days, and a remarkable recovery of colorectal mucosa was evident after 14 days of treatment. The amelioration of colon pathology co-existed with a significant decrease in MPO expression, overexpression of iNOS and reduction of nuclear NF-κB p65 in inflammatory cells, and the suppression of apoptosis in colonic epithelial cells. The simultaneous administration of Mesna and n-3 PUFAs is particularly effective in ameliorating DSS colitis in rats, by reducing oxidative stress, inflammation and apoptosis, probably through a mechanism that involves the inhibition of NF-κB and overexpression of iNOS.

α-Linolenic acid (ALA) is an anti-inflammatory agent in inflammatory bowel disease

Studies suggest that consumption of omega-3 (n-3) polyunsaturated fatty acids (PUFA) plays a protective role in inflammatory bowel disease; however, the use of plant-derived oils rich in α-linolenic acid (ALA) has not been widely investigated. The aims of this study were to test the effects of two different sources of (n-3) PUFA, fish and plant-derived oils, in two animal models of experimental colitis and to determine whether the (n-3) PUFA-enriched diets could ameliorate the inflammatory status. Rats were fed diets rich in corn, fish or sage oil with or without vitamin A supplementation for 3weeks then colitis was induced by adding dextran sodium sulfate to the drinking water or by injecting 2,4,6-trinitrobenzene sulfonic acid. We show that colitic rats fed the sage oil diets had a lower inflammatory response, improved histological repair and had less necrotic damage in the mucosa when compared to the corn and fish oil groups. Colonic damage and myeloperoxidase activity were significantly lower. Colonic mRNA levels of pro-inflammatory genes including interleukin IL-6, cyclooxygenase 2 and tumor necrosis factor α were markedly down-regulated in rats fed fish and sage oils compared to control. These results were supported by experiments in the human colonic epithelial cell line Caco-2, where ALA supplementation was shown to be effective in inhibiting inflammation induced by IL-1β by down-regulating mRNA levels of pro-inflammatory genes including IL-8, COX2 and inducible nitric oxide synthase. Taken together, these results suggest that plant-derived oil rich in ALA could ameliorate the inflammatory damage in colitis.

Perilla oil improves blood flow through inhibition of platelet aggregation and thrombus formation

The inhibitory effects of perilla oil on the platelet aggregation in vitro and thrombosis in vivo were investigated in comparison with aspirin, a well-known blood flow enhancer. Rabbit platelet-rich plasma was incubated with perilla oil and aggregation inducers collagen or thrombin, and the platelet aggregation rate was analyzed. Perilla oil significantly inhibited both the collagen- and thrombin-induced platelet aggregations, in which the thromboxane B₂ formation from collagen-activated platelets were reduced in a concentration-dependent manner. Rats were administered once daily by gavage with perilla oil for 1 week, carotid arterial thrombosis was induced by applying 35% FeCl₃-soaked filter paper for 10 min, and the blood flow was monitored with a laser Doppler probe. Perilla oil delayed the FeCl₃-induced arterial occlusion in a dose-dependent manner, doubling the occlusion time at 0.5 mL/kg. In addition, a high dose (2 mL/kg) of perilla oil greatly prevented the occlusion, comparable to the effect of aspirin (30 mg/kg). The results indicate that perilla oil inhibit platelet aggregation by blocking thromboxane formation, and thereby delay thrombosis following oxidative arterial wall injury. Therefore, it is proposed that perilla oil could be a good candidate without adverse effects for the improvement of blood flow.

Higher fecal bile acid hydrophobicity is associated with exacerbation of dextran sodium sulfate colitis in mice

Increased luminal bile acid hydrophobicity is associated with cytotoxicity and has been suggested to contribute to gut barrier dysfunction. The aim of this study was to compare 2 high-fat diets and a low-fat diet as to whether they modify fecal bile acid profile and hydrophobicity and/or susceptibility to dextran sodium sulfate (DSS) colitis in C57Bl/6J mice. Control and DSS-Control groups received a low-fat control diet [5.5% of total energy (E%) soy oil, 4.5 E% lard], and the DSS-Lard (5.5 E% soy oil, 54.5 E% lard) and DSS-Fish oil (5.5 E% soy oil, 27.2 E% lard and 27.2% menhaden oil) groups received high-fat diets. Feces for bile acid analysis were collected after 3-wk feeding, followed by induction of dextran DSS colitis (2 d 5% DSS in drinking water + 2 d tap water). Fecal bile acid hydrophobicity was elevated 76% in the lard group (P = 0.051) and 122% in the fish oil group (P = 0.001) compared with control, indicating potentially increased cytotoxicity. DSS caused severe colitis symptoms, evaluated as rectal bleeding, whereas all the controls were symptom free. The median symptom scores were: DSS-Control, 2.3 (IQR = 0.6, 3.0); DSS-Lard, 0.3 (IQR = 0, 2.3); and DSS-Fish oil, 2.4 (IQR = 1.9, 2.8). The only differences were DSS-Control vs. control (P < 0.001) and DSS-Fish oil vs. control (P < 0.001). Severity of symptoms in all colitic mice was positively correlated with fecal bile acid hydrophobicity (Spearman's ρ = 0.43; P = 0.028) and fecal deoxycholic acid concentration (Spearman's ρ = 0.39; P = 0.048). These results suggest that luminal bile acid modification, induced by altered dietary fat composition, may alter susceptibility to DSS colitis.

Expression of catalase in Lactobacillus fermentum and evaluation of its anti-oxidative properties in a dextran sodium sulfate induced mouse colitis model

Lactic acid bacteria are generally sensitive to hydrogen peroxide (H₂O₂). Lactobacillus plantarum ATCC14431 is one of the few lactic acid bacteria able to degrade H₂O₂ through the action of a manganese-dependent catalase (containing the katA gene). However, it is not a natural inhabitant of the intestinal tract and its bio-efficacy and survival in the gastrointestinal tract have never been tested. In this study, we successfully expressed the katA gene from L. plantarum ATCC14431 in L. fermentum I5007 and the recombinant L. fermentum exhibited almost 20-fold higher catalase activity than the empty vector control. The anti-oxidative properties of this catalase-producing L. fermentum were evaluated using a dextran sodium sulphate (DSS) induced colitis mice model. Compared with the control, mice receiving DSS alone had increased diarrhea and mucosa histological scores (P < 0.05), as well as lipid peroxidation (P < 0.05), myeloperoxidase (P < 0.05), and active NF-κB in colonic tissue (P < 0.05). Similar to vitamin E, treatment with recombinant L. fermentum mitigate these effects accompanied by a improvement in mucosa histological scores in the proximal colon (P < 0.05) and decreased lipid peroxidation (P < 0.05), myeloperoxidase (P < 0.05) and active NF-κB in colonic tissue (P < 0.05). In conclusion, the expression of catalase in L. fermentum increased its ability to survive when exposed to aerated environment in vitro and conferred the anti-oxidative and anti-inflammatory effects in the DSS induced colitis model.

SOCS3 transactivation by PPARγ prevents IL-17-driven cancer growth

Activation of the transcription factor PPARγ by the n-3 fatty acid docosahexaenoic acid (DHA) is implicated in controlling proinflammatory cytokine secretion, but the intracellular signaling pathways engaged by PPARγ are incompletely characterized. Here, we identify the adapter-encoding gene SOCS3 as a critical transcriptional target of PPARγ. SOCS3 promoter binding and gene transactivation by PPARγ was associated with a repression in differentiation of proinflammatory T-helper (TH)17 cells. Accordingly, TH17 cells induced in vitro displayed increased SOCS3 expression and diminished capacity to produce interleukin (IL)-17 following activation of PPARγ by DHA. Furthermore, naïve CD4 T cells derived from mice fed a DHA-enriched diet displayed less capability to differentiate into TH17 cells. In two different mouse models of cancer, DHA prevented tumor outgrowth and angiogenesis in an IL-17-dependent manner. Altogether, our results uncover a novel molecular pathway by which PPARγ-induced SOCS3 expression prevents IL-17-mediated cancer growth.

Effects of a high fat or a balanced omega 3/omega 6 diet on cytokines levels and DNA damage in experimental colitis

OBJECTIVE

High-fat diets have been shown to be a risk factor for ulcerative colitis (UC). Omega-6 polyunsaturated fatty acids are considered to increase lipid peroxidation, while the omega-3 polyunsaturated fatty acid exerts a chemopreventative effect. We evaluated the effect of high-fat diets (20%) enriched with fish or soybean oil on colonic inflammation and DNA damage in dextran sulfate sodium-induced colitis.

METHODS

Male Wistar rats (28-30 days) were fed an American Institute of Nutrition (AIN)-93 diet for 47 days and divided into five groups: control normal fat non-colitic (C) or control colitis (CC), high soybean fat group (HS) colitis, high fish fat group colitis, or high-fat soybean plus fish oil colitis. UC was induced from day 35 until day 41 by 3% dextran sulfate sodium. On day 47, the rats were anesthetized; blood samples collected for corticosterone determination, and the distal colon was excised to quantify interleukin-4 (IL-4), IL-10, and interferon-gamma levels, myeloperoxidase activity, histological analyses, and DNA damage. The disease activity index was recorded daily.

RESULTS

The disease activity index, histological analysis, myeloperoxidase activity, IL-4, interferon-gamma, and corticosterone levels did not differ among the colitic groups. IL-10 was significantly increased by the high fish fat group diet in relation to HS, but only the high soybean-fish fat diet increased the IL-10/IL-4 ratio (anti-inflammatory/pro-inflammatory) to levels closer to the C group and reduced DNA damage compared to the HS group (P<0.05).

CONCLUSION

The data show that high-fat diets did not exacerbate UC and suggest that the soybean and fish oil mixture, more than the fish oil alone, could be a complementary therapy to achieve a cytokine balance in UC.

Effects of pharmaconutrients on cellular dysfunction and the microcirculation in critical illness

PURPOSE OF REVIEW

A growing body of data has revealed that specific nutrient deficiencies contribute to microvascular and cellular dysfunction following critical illness. Further, targeted administration of these 'pharmaconutrients' may reverse or improve this dysfunction and improve clinical outcome.

RECENT FINDINGS

Specific nutrient therapy with glutamine protects cellular metabolism and vascular function via induction of heat shock proteins, which are key proteins found to be deficient following acute illness. Arginine becomes rapidly deficient following trauma and surgery. This leads to significant immunosuppression, which when treated by arginine administration significantly reduces postoperative infection. Omega-3 fatty acids attenuate the inflammatory response and provide for resolution of ongoing inflammatory injury via production of resolvins/protectins. Antioxidants (vitamin C and selenium) and trace elements (zinc) become rapidly depleted in critical illness and replacement appears vital to ensure optimal cellular and microvascular function. Data on targeted metabolic (mitochondrial) therapies (i.e. co-enzyme Q10) show promise to improve myocardial function following cardiac surgery.

SUMMARY

These specific nutrients have newly discovered vital mechanistic roles in the optimization of cellular and microcirculatory function in critical illness and injury. A growing body of literature is demonstrating that correction of key nutrient deficiencies via therapeutic administration of these pharmaconutrients can improve clinical outcome in critically ill patients.

Effects of alpha-linolenic acid on colonic secretion in rats with experimental colitis

BACKGROUND

Few studies have specifically examined the effects of n-3 polyunsaturated fatty acids (PUFAs) on intestinal water and ion secretion in ulcerative colitis (UC). The aim of this study was to examine the contribution of prostaglandins (PGs) and leukotrienes (LTs) to mucosal secretion in intestines with UC and to evaluate the effect of dietary n-3 PUFAs on diarrhea in UC.

METHODS

We measured the short-circuit current (Isc), using the Ussing chamber method, and fatty acid composition in the colonic mucosa of rats with dextran sulfate sodium (DSS)-induced experimental colitis. The DSS-treated rats were fed either a perilla oil-enriched diet (perilla group) or a soybean oil-enriched diet (soybean group); a control group did not undergo DSS administration.

RESULTS

The bradykinin-stimulated DeltaIsc in the soybean and perilla groups was significantly higher than that in the control group. The mucosal level of arachidonic acid in the perilla group was significantly lower than that in the soybean group. The mucosal levels of alpha-linolenic acid and EPA in the perilla group were significantly higher than those in the soybean group. The bradykinin-stimulated DeltaIsc was significantly suppressed after pretreatment with indomethacin in both the soybean and perilla groups, and was also significantly reduced in both groups after pretreatment with AA861. The suppression of bradykinin-stimulated DeltaIsc by the addition of AA861 was significantly higher in the perilla group than in the soybean group.

CONCLUSIONS

Our results suggest that supplementation with alpha-linolenic acid, in combination with a lipoxygenase inhibitor, could suppress the increase in Cl- secretion in patients with UC.

Interactive effects of dietary resistant starch and fish oil on short-chain fatty acid production and agonist-induced contractility in ileum of young rats

We have shown independently that dietary fiber and n-3 fatty acids can affect gut function. This study investigated the interactive effects of resistant starch (RS) (as high amylose maize starch [HAMS]) and tuna fish oil on ileal contractility. Four-week-old male Sprague Dawley rats were fed 4 diets that contained 100 g/kg fat as sunflower oil or tuna fish oil, with 10% fiber supplied as alpha -cellulose or HAMS for 6 weeks. Fish oil feeding led to higher ileal n-3 fatty acid levels (mainly as DHA) and higher agonist-induced maximal contractility with an RS effect noted for carbachol. HAMS-containing diets resulted in lower colonic pH and higher total short-chain fatty acids (SCFA), but not for butyrate with fish oil. Low prostanoid responses in young rats were enhanced by fish oil independent of RS. The order of muscarinic receptor subtype responses were different compared to older rats; fish oil feeding altered the sensitivity of the M(1) receptor subtype. Although little interactive effects were demonstrated, these data suggest developmental changes in ileal receptor systems with independent effects of RS and fish oil on some bowel properties in juvenile rats.

Fish oil decreases oxidative DNA damage by enhancing apoptosis in rat colon

To determine if dietary fish oil protects against colon cancer by decreasing oxidative DNA damage at the initiation stage of colon tumorigenesis, oxidative DNA damage, proliferation, and apoptosis were assessed by colonic crypt cell position using quantitative immunohistochemical analysis of 8-hydroxydeoxyguanosine (8-OHdG), Ki-67, and TUNEL assay, respectively. Sixty rats were provided one of two diets (corn oil or fish oil) and dextran sodium sulfate (DSS, an inducer of oxidative DNA damage) treatments (no DSS, 3% DSS, or DSS withdrawal). Fish oil feeding resulted in lower 8-OHdG levels (P = 0.038), higher levels of apoptosis (P = 0.035), and a lower cell proliferative index (P = 0.05) compared with corn oil feeding. In the top third of the crypt, fish oil caused an incremental stimulation of apoptosis with increased DNA damage (P = 0.043), whereas there was no such relationship with corn oil. Because polyps and tumors develop from DNA damage that leads to loss of growth and death control, the significant difference in fish oil vs. corn oil on these variables may account, in part, for the observed protective effect of fish oil against oxidatively induced colon cancer.

Dietary olive oil supplemented with fish oil, rich in EPA and DHA (n-3) polyunsaturated fatty acids, attenuates colonic inflammation in rats with DSS-induced colitis

Previous studies proposed a protective role of the dietary intake of (n-3) PUFA in human inflammatory bowel disease (IBD), but almost no studies have been performed using olive oil. The aims of the present study were to test the beneficial effects of an olive oil-based diet with or without fish oil, rich in (n-3) PUFA, in the dextran sodium sulfate (DSS) model of rat colitis and to elucidate the mechanisms involved in their potential beneficial effects, with special attention to the production of some of the mediators involved in the intestinal inflammatory response, such as leukotriene B(4) (LTB(4)), tumor necrosis factor alpha (TNFalpha) and nitric oxide (NO). Rats were fed the different diets for 2 wk before colitis induction and thereafter until colonic evaluation 15 d later. Colitic rats fed the olive oil-based diet had a lower colonic inflammatory response than those fed the soybean oil diet, and this beneficial effect was increased by the dietary incorporation of (n-3) PUFA. A restoration of colonic glutathione levels and lower colonic NO synthase expression occurred in all colitic rats fed an olive oil diet compared with the control colitic group that consumed the soybean oil diet. However, (n-3) PUFA incorporation into an olive oil diet significantly decreased colonic TNFalpha and LTB(4) levels compared with colitic rats that were not supplemented with fish oil. These results affirm the benefits of an olive oil diet in the management of IBD, which are further enhanced by the addition of (n-3) PUFA.

Trophic and cytoprotective nutrition for intestinal adaptation, mucosal repair, and barrier function

Intestinal epithelial cell turnover (proliferation, migration, differentiation, and apoptosis) and gut barrier functions are dynamic processes that are markedly affected by nutritional status, the route of feeding, and the adequacy of specific nutrients in the diet. Emerging studies are defining potential therapeutic roles for specific nutrients and diet-derived compounds (including arginine, glutamate, glutamine, glutathione, glycine, vitamin A, zinc, and specific lipids) in gut mucosal turnover, repair, adaptation after massive bowel resection, and barrier function. The role and regulation of endogenous bowel flora in generating short-chain fatty acids from diet-derived fiber and other diet-derived compounds and the effects of these agents on gut function are increasingly being elucidated. Results of these investigations should define new nutritional methods for trophic and cytoprotective effects on the intestine in conditions such as inflammatory bowel disease, malnutrition, and short bowel syndrome.

The relationship between the concentration of dextran sodium sulfate and the degree of induced experimental colitis in weanling rats

BACKGROUND

Although a dextran sodium sulfate (DSS)-induced colitis is commonly used as an ulcerative colitis (UC) model in adult rodents, there are no studies using this model in young animals. We examined differences in the severity of DSS-induced colitis as a function of the concentration of DSS administered and sought to establish a DSS-induced colitis model in young rats.

METHODS

We administrated different concentrations of DSS solution (2%, 3%, and 4%) to 4-week-old weanling rats and compared their clinical findings, colonic histologic findings, mucosal leukotriene B4 (LTB4) production, and mucosal blood flow with control weanling rats and 8-week-old adult rats given 4% DSS for induced colitis.

RESULTS

Clinical symptoms, such as diarrhea and rectal bleeding, histologic findings, and disturbance of mucosal microcirculation in weanling rats given 4% DSS were significantly more severe than those in adult rats given the same treatment. Three of 10 rats given 2% DSS had no bloody stool and 2 of 10 rats given 4% DSS died during the experimental periods. Clinical symptoms, hemoglobin levels, histologic damage scores, mucosal LTB4 production, and mucosal blood flow became more severely deranged as the concentration of DSS increased from 2% to 4%.

CONCLUSION

These findings suggest that we can adjust disease severity in UC model for young children by giving different concentrations of DSS to weanling rats.

Effects of n-3 polyunsaturated fatty acids on indomethacin-induced changes in eicosanoid production and blood flow in the gastric mucosa of rats

We investigated the effects of n-3 polyunsaturated fatty acids (PUFAs) on non-steroidal anti-inflammatory drug (NSAID)-induced changes in microcirculation and eicosanoid production in the gastrointestinal mucosa. We measured gastric mucosal blood flow using laser Doppler flowmetry, assessed the fatty acid composition in the mucosal phospholipids, and quantified the production of prostaglandin E2 (PGE2), leukotriene B4, and leukotriene C4 (LTB4 and C4) from the mucosa with the stimulation of calcium ionophore 20 min after an injection of indomethacin or vehicle in rats fed a diet containing different compositions of alpha-linolenic acid. Four weeks after the initiation of the test diet the arachidonic acid level in gastric mucosal phospholipids was significantly lower in the perilla group than in the other three groups. Conversely, alpha-linolenic acid and eicosapentaenoic acid (EPA) were significantly higher in the perilla group than in the other three groups. The percent of gastric mucosal blood flow in the three groups administered indomethacin were significantly lower than that in the control group injected with vehicle alone. The percent of gastric mucosal blood flow in the perilla group was significantly higher than that in the corn group. LTB4 and LTC4 production from the gastric mucosa in the soybean and corn groups were significantly higher than those in the control group, and the LTC4 production in the perilla group was significantly lower than that in the corn group. There were no significant differences in PGE2 production among the four groups. Our results suggest that alpha-linolenic acid affectively suppressed the indomethacin-induced decreases in gastric mucosal blood flow by increasing EPA and decreasing the levels of arachidonic acid and LTC4 in the gastric mucosa.

Dietary fish oil increases acetylcholine- and eicosanoid-induced contractility of isolated rat ileum

The long-chain (n-3) polyunsaturated fatty acids (PUFA) have been reported to exhibit health benefits and healing properties for the gastrointestinal tract. The aim of this study was to investigate the effects of dietary fish oil supplementation on the in vitro contractility of gut tissue. Rats (9 wk old) were fed synthetic diets supplemented with 170 g/kg Sunola oil (SO; 850 g/kg as oleic acid [18:1(n-9)]) or with 100 g/kg of the SO replaced by saturated animal fat (SF) or fish oil (FO) for 4 wk. In the colon, there was no difference in the sensitivity (50% effective concentration) or the maximal contraction among the three dietary groups induced by acetylcholine or 8-iso-prostaglandin (PG)E(2) with the rat colon being relatively insensitive to the thromboxane mimetic U-46619. However, in the ileum, the FO group had greater maximal contractions induced by acetylcholine and 8-iso-PGE(2) compared with the SO and SF groups (P < 0.05), and greater maximal contractions induced by PGE(2), PGF(2alpha) and U-46619 compared with the SF group (P < 0.05). FO feeding increased the incorporation of (n-3) PUFA (eicosapentaenoic [20:5(n-3)], docosapentaenoic [22:5(n-3)] and docosahexaenoic acids [22:6(n-3) primarily at the expense of (n-6) PUFA (linoleic [18:2(n-6)] and arachidonic acids [20:4(n-6)]) in the ileum and colon phospholipid fatty acids (P < 0.05). The FO group had a lower cecal digesta pH (P < 0.001) and a greater butyrate concentration than the SF group (P < 0.05). These results suggest that dietary (n-3) PUFA may modulate the contractility of the small intestine.

Rose hip (Rosa canina L.) oil obtained from waste hip seeds by different extraction methods

From the rose hip seed, which is generally a waste material, valuable oil can be obtained for medicinal use. Various extraction methods have been compared: traditional solvent extraction with ultrasound-, microwave-, sub- and supercritical fluid extraction (SFE). Unsaturated fatty acid (UFA: oleic-, linoleic- and linolenic acid; 16.25-22.11%, 35.94-54.75%, 20.29-26.48%) and polyunsaturated fatty acid (PUFA:linoleic- and linolenic acid) content were over 90% and 60% in the recovered oils. The oils contained different amounts of metals. The concentration of some metals, particularly iron in microwave oil (27.11 microg g(-1)) is undesirable from the aspect of stability. By traditional solvent extraction, oil was obtained in 4.85 wt/wt%. Subcritical FE appeared to be the best method for the recovery of rose hip oil with highest oil yield (6.68 wt/wt%), carotene- (145.3 microg g(-1)) and linoleic acid content (54.75%). Supercritical FE without organic solvent is suitable for mild recovery of oil. The oil was rich in UFA and PUFA (92.7% and 76.25%) and contained the lowest amount of carotene and pheophytin (36.3 and 45.8 microg g(-1)). Oil yield in most new extraction methods (microwave extraction, super- and subcritical FE) was higher than in the case of traditional Soxhlet extraction. The main benefit of supercritical FE with CO2 is the solvent free oil while in the case of other extractions evaporation of the solvent is needed. Although the content of bioactive compounds in oils was different, all oils may be appropriate for medicinal use.

Effects of n-3 polyunsaturated fatty acids on dermatitis in NC/Nga mice

The administration of n-3 polyunsaturated fatty acids (PUFAs) is known to be effective against allergic diseases by suppressing the production of eicosanoids derived from arachidonic acid. To investigate the mechanisms and efficacy of n-3 PUFA treatment in patients with atopic dermatitis (AD), we administered four different formulas of alpha-linolenic acid for 6 weeks in an AD model using NC/Nga mice. According to the doses of alpha-linolenic acid given, the levels of alpha-linolenic acid, eicosapentaenoic acid, and docosahexaenoic acid in the red blood cell membranes increased while the levels of linoleic acid and arachidonic acid decreased. However, there was no significant difference among the four dose groups in clinical skin severity score, histopathological findings of skin lesions, or levels of total plasma IgE. Moreover, there was no significant difference in the production of leukotriene B(4) and Leukotriene C(4) from skin lesions after stimulation with A23187 among the groups, although the production of prostaglandin E(2) (PGE(2)) was significantly reduced and skin blood flow in the ear was significantly higher in the group given the highest dose of alpha-linolenic acid. Our results suggest that the administration of alpha-linolenic acid can change the fatty acid composition, PGE(2) production, and skin blood flow but may not prevent the development of dermatitis in NC/Nga mice.