Orientador: Maria Cristina Cintra Gomes Marcondes / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-19T11:32:15Z (GMT). No. of bitstreams: 1 Pertile_Tatiane_M.pdf: 1613871 bytes, checksum: 2d715c00e32e2a411050801a7a1ac95f (MD5) Previous issue date: 2011 / Resumo: O câncer pode promover a morte do hospedeiro, pois durante sua evolução há modificações da homeostasia dos processos metabólicos, promovendo profundas alterações caracterizadas como caquexia, que por sua vez relaciona-se à diminuição da qualidade e do tempo de vida do hospedeiro. Assim, no presente estudo, analisamos os efeitos da evolução do crescimento de neoplasia - carcinossarcoma de Walker 256 - em ratos jovens e adultos e os efeitos modulatórios do tratamento desses animais com EPA (ácido eicosapentaenóico) sobre o processo de caquexia e a concentração de citocinas anti e proinflamatórias no músculo gastrocnêmio, pois o tecido muscular é o tecido mais afetado no processo de caquexia. Foram utilizados 108 ratos Wistar machos, com idade de 30 dias (jovens) e 100 dias (adultos), os quais foram distribuídos de acordo com o local de implante tumoral, intraperitônio e subcutâneo, e tratamento ou não com ácido eicosapentaenóico, 100?g/Kg de peso corpóreo. Os animais receberam gavagem diária do EPA (animais tratados) ou de óleo mineral (grupos sem tratamento) até a fase pré-agônica. A partir dos órgãos coletados, foram calculados o ganho de peso corpóreo, os pesos relativos de cada órgão, do tumor e da carcaça. Com o objetivo de identificarmos a via de degradação protéica predominante nos grupos experimentais, foram avaliados, no tecido muscular, o teor de proteína muscular total e as atividades das seguintes enzimas: chymotrypsin-like, catepsinas B e H, calpaína e fosfatase alcalina,. A partir do sangue desses animais foram feitas análises fluorimétricas do fator de crescimento semelhante à insulina (IGF) e das citocinas - interleucinas 4 (IL-4), 6 (IL-6) e 10 (IL-10), interferon gama (INF-?) e leptina, utilizando-se kits específicos para citômetro de fluxo de fluorescência (Luminex). Também foi analisada a expressão gênica, no tecido muscular, por reação em cadeia da polimerase em tempo real (PCR-RT), para a via proteossômica e também para os fatores eucarióticos de inicialização. Os dados indicam efeitos modulatórios do EPA sobre o tecido muscular (manutenção da proteína e do peso), principalmente para os grupos jovens, e também no processo inflamatório crônico (aumento de citocinas pró e antiinflamatórias). Entretanto, efeitos mais expressivos do EPA não foram verificados na prevenção da espoliação de gordura (gordura perirrenal e leptina), no processo de síntese protéica (manutenção da expressão gênica de fatores eucarióticos de inicialização) ou também sobre a via proteossômica / Abstract: Cancer can promotes the host death, because during its evolution there are modifications in metabolic processes of homeostasis, promoting deep changes characterized as cachexia, which in turn relates with reduction in quality and lifetime of the host. Thus, in this study, we analyze the effects of development in Walker 256 carcinoma evolution - in young and adults rats and the modulatory effect of treatment with EPA (eicosapentaenoic acid) in gastrocnemius muscle as this tissue is the most affected in the cachexia process. Wistar males rats were used (n=108 animals), 30 days-old (young) and 100 days-old (adults), which were distributed according to the tumour implant, intraperitoneally and subcutaneously and treatment or not with eicosapentaenoic acid, 100 ?g/Kg of body weight. The animals receive daily EPA by gavage (treated animals) or nujol (sham groups) and were cared up to pre-agonic state. The bodies weight were measured and the body weight gain was calculated, as well the relative weights of tissues, tumour, and carcass. In order to identify the predominant pathway of protein degradation the total muscle protein content and proteolytic enzymes activities (chymotrypsin-like, cathepsin B and H, calpain and alkaline phosphatase) were measured in gastrocnemius muscle. The blood samples were assessed to measure the insulin-like growth factor 1 (IGF-1), leptin and the cytokines - interleukins (IL-4), 6 (IL-6) and 10 (IL-10), gamma interferon (INF-?), using specific kits for cytometer fluorescence (Luminex). It was also examined gene expression, in the muscle tissue, by real-time polymerase chain reaction (RT-PCR), assessing keys of ubiquitin-proteasome pathway and also on the eukaryotic initiation factors. The data indicated some modulatory effects of EPA on the muscle tissue (maintenance of protein and weight), mainly for the young rats, and also the chronic inflammatory process. However, more expressive effects of EPA have not been verified as preventing fat wasting (perirenal fat and leptin), nor in the process of protein synthesis (maintenance of eukaryotic initiating factors gene expression) or also in the ubiquitin-proteasome via / Mestrado / Fisiologia / Mestre em Biologia Funcional e Molecular

O glioblastoma multiforme (GBM) é a forma mais maligna de tumor cerebral, originado de células astrocíticas e caracterizado pela intensa proliferação, angiogênese e invasão celular pelo parênquima cerebral normal. O ácido gama-linolênico (GLA) mostrou ter ações anti-tumorais, nos processos de proliferação, migração e angiogênese. Utilizou-se o modelo ortotópico de GBM de rato (C6) e o modelo ex vivo tratados com GLA para análise de migração e proliferação celular. Foi observada uma redução da imunomarcação do fator de crescimento para endotélio vascular (VEGF), seu receptor Flt-1 e da metaloproteinase-2 de matriz, com consequente diminuição de vasos após o tratamento com GLA. No modelo ex vivo observou que o GLA reduziu a distância de migração e a mitose das células tumorais e também causou aumento das células tumorais em processo de apoptose. Os resultados revelaram que o GLA foi capaz de modular a expressão de algumas proteínas envolvidas nos processos angiogênico, migratório e proliferativo do GBM, o que sugere a sua utilização no tratamento desta patologia. / Glioblastoma multiforme (GBM) is the most malignant form of brain tumour originating from astrocytes and is characterized by intense proliferation, angiogenesis and cell invasion through the normal brain parenchyma. Gamma-linolenic acid (GLA) has anti-tumour activities in the processes of proliferation, migration and angiogenesis. This study used the orthotopic GBM rat model (C6) and ex vivo model treated with GLA to analyze cell migration and proliferation. Decreased immunostaining was observed for vascular endothelial growth factor (VEGF), its receptor Flt-1 and matrix metalloproteinase-2, with consequent reduction of blood vessels after treatment with GLA. In the ex vivo model GLA reduced the migration distance and mitosis of tumor cells and increased tumour cell apoptosis. The results revealed that GLA was able to modulate the expression of several proteins involved in angiogenesis, migration and proliferation in GBM, supporting the use of GLA in the treatment of this disease.

La dysplasie broncho-pulmonaire (DBP), complication fréquente de la prématurité, atteint 30% des nouveau-nés de faible poids de naissance. L’hypertension artérielle pulmonaire persistante du nouveau-né (HTAPP), associé ou non à la DBP, résulte d’une mauvaise adaptation à la vie extra-utérine et survient dans diverses situations pathologiques (prématurité, sepsis, inhalation de méconium, hernie diaphragmatique congénitale…). Ces 2 pathologies sont grevées d’une morbidité et d’une mortalité importante en période périnatale. En effet, certaines situations d’HTAPP ou de DBP sévères restent réfractaires aux thérapeutiques actuelles.Les acides gras polyinsaturés oméga 3 (AGPI ω-3) sont des nutriments aux propriétés bénéfiques sur le système circulatoire et pulmonaire, mais également sur le développement fœtal, démontrés par de nombreuses études expérimentales et cliniques. La déhydroépiandrostérone (DHEA) est une hormone stéroïdienne dont le taux de sécrétion chez l’homme diminue avec l’âge. Des études récentes ont démontré un effet cardio-protecteur mais également un effet vasodilatateur pulmonaire et préventif de lésions de DBP dans des modèles expérimentaux.Les buts de notre travail étaient 1) d’étudier l’effet d’une supplémentation en AGPI ω-3 dans un modèle expérimental de DBP induite par hyperoxie chez le raton, 2) d’étudier l’effet circulatoire d’injection d’AGPI ω-3 (in vivo) dans un modèle d’étude de la circulation pulmonaire chez le fœtus de brebis chroniquement instrumenté, et d’étudier les mécanismes d’action AGPI ω-3 (anneaux vasculaires isolés) , enfin 3) d’étudier l’effet circulatoire de la DHEA (in vivo) dans le modèle de fœtus de brebis et d’étudier les mécanismes d’actions de la DHEA sur la circulation pulmonaire fœtale (in vivo)._x000D_Nous avons démontré que la supplémentation par voie orale en AGPI ω-3 de rates gestantes à la fin de la gestation et après la naissance permettait de prévenir, chez les ratons nouveau-nés, les lésions de DBP induites par une exposition chronique à l’hyperoxie. Ces lésions étaient retrouvées dans les groupes contrôles (eau et AGPI ω-6). Cette étude n’avait pas retrouvée d’effet bénéfique des AGPI ω-3 sur le remodelage vasculaire induit.L’injection d’acide eicosapentaènoique (EPA) chez le fœtus de brebis a révélé un effet vasodilatateur pulmonaire puissant avec une baisse significative et prolongée des résistances vasculaires pulmonaires (RVP), en comparaison à l’injection d’acide docosahéxaènoique (DHA) ou de l’excipient (faible dose d’éthanol). L’effet vasorelaxant de l’EPA sur des anneaux isolés pré-contractés était plus important que celui du DHA à dose équivalente, et il était dose- et endothélium-dépendent. Enfin, cet effet impliquait la voie de production du NO puisqu’il était diminué lors du traitement des anneaux par le L-Nitro-Arginine (LNA), inhibant la NO synthase.L’étude de perfusion en bolus de DHEA dans le lit pulmonaire vasculaire chez le fœtus de brebis instrumenté mettait en évidence un effet vasodilatateur bref. Cet effet était dose-dépendant avec une baisse plus prononcée des RVP et une durée plus importante pour des doses de DHEA plus importantes. Enfin l’étude des mécanismes d’action retrouvait une inhibition de l’effet de la DHEA par le LNA, démontrant une action vasodilatatrice par activation de production du NO.L’ensemble de ces travaux permet de suggérer que les AGPI ω-3 représentent des nutriments intéressants en période périnatale (grossesse, allaitement et per os), notamment en traitement préventif dans les situations à risque de DBP, ou curatif en cas d’HTAPP. La DHEA reste une piste dans le traitement de l’HTAP, mais semble pour l’instant plus difficile à instaurer en clinique humaine. / Bronchopulmonary dysplasia (BPD), a common complication of prematurity, reached in 30% of newborns with very low birth weight. Persistent pulmonary hypertension of the newborn (PPHN), with or without BPD, results in poor adaptation to extrauterine life and occurs in various pathological conditions such as prematurity, sepsis, inhaled meconium, or diaphragmatic hernia Congenital. The mortality and morbidities of these two diseases are high in the perinatal period. Severe PPHN or BPD are refractory to current treatment.Polyunsaturated fatty acids omega-3 (ω-3 PUFA) are nutrients with beneficial properties on the circulatory and pulmonary system, but also on fetal development, demonstrated by many experimental and clinical studies. Dehydroepiandrosterone (DHEA) is a steroid hormone whose secretion levels in humans decreases with age. Recent studies have demonstrated a cardio-protective effect of diet DHEA supplementation but also a pulmonary vasodilator and preventive effect of DBP injury in experimental models.The aims of our study were : 1) to study the effect of PUFA ω-3 supplementation in an experimental model of hyperoxia-induced DBP in pups; 2) to study effect on pulmonary circulation of infusion of ω-3 PUFAs (in vivo) in model of chronically instrumented fetal sheep, and to analyze the mechanisms of action of ω-3 PUFA (isolated vascular rings); and finally 3) to study the in vivo effect of DHEA in fetal pulmonary circulation in the same model of fetal sheep and to understand the mechanisms of action of DHEA._x000D_We have demonstrated that supplementation with diet PUFA ω-3 on pregnant rats at the end of gestation and after birth prevent BPD injuries induced by chronic exposure to hyperoxia in pups. These lesions were found in the control groups (water and ω-6 PUFA). ω-3 PUFA supplementation did not prevent vascular remodeling.Infusion of eicosapentaenoic acid (EPA) in sheep fetus showed a potent pulmonary vasodilator effect as compared to docosahexaenoic acid (DHA) or excipient (low dose of ethanol). Vasorelaxant effect of EPA on pre-contracted isolated rings was more important than DHA at equivalent dose, and was dose- and endothelium-dependent. This effect involves NO production.Bolus DHEA perfusion in the pulmonary vascular bed study on instrumented fetal sheep highlighted an acute vasodilator effect. This effect was dose-dependent with a more pronounced and sustained decrease in PVR at highest doses of DHEA. Finally, mechanisms of action study found an inhibition of the effect of DHEA by the LNA, indicating that DHEA-induced vasodilation is NO dependant.Taken together, our results suggest that supplementation with ω-3 PUFAs and DHEA within the perinatal period may prevent BPD and PPHN in high risk conditions including preterm birth, premature rupture of the membrane or intrauterine growth restriction.

Ageing is accompanied by a progressive decline in skeletal muscle mass and strength which may lead to impaired ability to perform activities of daily living in older adults. Although the exact cause of the gradual decline in muscle mass is unknown, identifying efficient strategies aiming to prevent age-related loss of muscle mass and strength is important in order to promote healthy ageing. The overall aim of this thesis was to explore the effects of resistance training alone or combined with a healthy diet on skeletal muscle mass and function of healthy recreationally active older women and to determine mechanisms by which elevated systemic inflammation may contribute to the age-related decline of muscle mass in older adults. The combination of resistance training and a healthy diet induced gains in leg lean mass as well as greater gains in dynamic explosive force than resistance training alone in healthy recreationally active older women. The observed gains in leg lean mass were accompanied by increases in the size of type IIA muscle fibres together with down-regulation in gene expression of a pro-inflammatory factor (IL-1β) and upregulation in gene expression of a regulator of cellular growth (mTOR) in skeletal muscle of older women. Additionally, reduced muscle protein synthesis and size of muscle cells may mediate the detrimental effects of elevated circulating markers of inflammation on muscle mass in older adults. In conclusion, the present thesis depicts mechanistic links between elevated systemic marker of inflammation and muscle mass and provides new information on the effects of combined resistance training and healthy diet on muscle mass and strength in a group of healthy recreationally active older women. This knowledge is instrumental for development of strategies aiming to prevent age-related loss of muscle mass and function.

Omega 3 poly unsaturated fatty acids (n-3 PUFA) have been shown to protect against sudden cardiac death following myocardial infarction and reduce the risk of ventricular arrhythmias in patients with heart failure. At the inception of this study, there was one clinical study that reported n-3 PUFA supplementation reduced the risk of atrial fibrillation (AF) following CABG. As AF is a very common arrhythmia and as there are no safe and effective means of preventing AF, we designed this study to further validate the findings of the previous study in a more robust study design. In addition, this study also aimed to evaluate the cellular changes that underpin the beneficial anti-arrhythmic effect of n-3 PUFA.The outcome of this study shows that n-3 PUFA does not reduce the risk of AF following CABG. However, short term supplementation with n-3 PUFA reliably increases the membrane incorporation in phospholipids and results in alteration in the expression levels of cardiac calcium handling proteins phospholamban and ryanodine receptors. In addition, such incorporation in animal (rat) ventricular myocytes leads to changes in the rate of decay of the systolic calcium transient and an increase in the amplitude of the caffeine induced calcium transient thereby indicating a greater activity of SERCA. These findings needs further evaluation but is clearly interesting as the clinical situations where n-3 PUFA have been shown to be anti-arrhythmic are situations where cellular calcium overload is the main mechanism of arrhythmogenesis.

Endocannabinoids are endogenous lipid mediators involved in various biological processes, and have immunomodulatory and anti-inflammatory activities. Anandamide (arachidonoyl ethanolamine, AEA) and 2-arachidonoyl glycerol (2-AG) are the main representatives of this group. The endocannabinoid receptors CB1 and CB2 with AEA have been found in human HaCaT keratinocytes and fibroblasts, but the metabolic pathway leading to endocannabinoid production in the skin has not been fully elucidated. This study aimed to investigate the profile of endocannabinoids and their main metabolizing enzymes in human skin cells and assess whether omega-3 polyunsaturated fatty acids (n-3 PUFA) altered these profiles. In addition, an investigation was carried out to check whether UV radiation could stimulate the production of endocannabinoids and N-acylethanolamines (NAE) in human skin cells. For this purpose HaCaT keratinocytes and 46RB.1N fibroblast cells were treated with 10 and 50µM of eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) or oleic acid (OA) in the presence or absence of UVR (15mJ/cm2). Data suggest that n-3 PUFA may both directly (by up-regulating NAPE-PLD levels) and indirectly (by decreasing FAAH levels) increased endocannabinoid and NAE levels in HaCaT keratinocytes and 46BR.IN fibroblasts. DHA treatment significantly decreased COX-2 expression in the absence of UVR and inhibited UVR-induced COX-2 overexpression in 46BR.IN fibroblasts. In contrast, DHA appeared to induce COX-2 up-regulation in the absence of UVR and did not prevent UVR induced COX-2 up-regulation in HaCaT keratinocytes. EPA appeared to induce COX-2 down-regulation in the absence of UVR and did not prevent UVR induced COX-2 up-regulation in both HaCaT keratinocytes and 46BR.IN fibroblasts. UVR did not have any significant effect on endocannabinoid and NAE biosynthesis. However, UVR induced endocannabinoid production in some experiments of this study. A clinical study was carried on 16 volunteers from two different ethnic groups and two different skin types. The purpose was to assess the effect of UVR on the serum endocannabinoids and NAE, therefore, the volunteers were subjected to multiple doses (1.3, SED/ 6 min) of UVR for 6 weeks. Data showed that UVR did not have major effect on human serum NAE in both skin phototypes II and V but increased 2-AG in human serum in both skin types but the more pronounced effect was evident in skin phototypes V rather than in skin phototypes II. Human serum docosahxaenoylethanolamide levels were found to be higher in White Caucasians group (skin phototypes II). Based on these it can be concluded that n-3 PUFA and UVR alter the endocannabinoids and NAE profile in HaCaT keratinocytes and 46BR.IN fibroblasts. In addition, results of the clinical study indicated that UVR has no major effects on serum endocannabinoids or NAE therefore, further studies are required to address this question in vivo.

Memoria para optar al Título Profesional de Médico Veterinario / El objetivo del estudio fue evaluar el efecto de suplementar con Ácidos Grasos Poliinsaturados omega 3 (AGPI -3) la dieta de cerdas reproductoras sobre su rendimiento reproductivo, reflejado en su futura camada. Por 30 días a partir de 3 días previos al parto, 90 cerdas, 45 del Grupo Control (GC) fueron alimentadas con una dieta de lactancia y otras 45, Grupo Tratamiento (GT), con la dieta control más 5 g/kg de AGPI -3 (Crandon S.A., Chile). Registrándose consumo de alimento diario y el rendimiento reproductivo de las cerdas en el parto siguiente. El consumo de alimento fue menor en GT durante la primera semana (P = 0,002). En cerdas jóvenes (< 4 partos), GT presentó mayor número de lechones nacidos totales (P = 0,002) y nacidos vivos (P = 0,001) que GC. No hubo diferencias (P > 0,05) en el número de fetos momificados ni de ballicos entre grupos. En cerdas viejas (> 5 partos), se obtuvo un menor número de ballicos en GT en comparación a GC (P = 0,021). Sin embargo, el número de nacidos muertos fue mayor en GT que en GC (P = 0,026). Posteriormente, GT presentó una elevada mortalidad nacimiento-destete, no existiendo diferencias en el número de kilos destetados entre grupos, sin obtenerse un beneficio económico para GT. Los resultados demuestran que la suplementación con AGPI -3 tuvo efecto sobre los parámetros productivos de las cerdas jóvenes; siendo necesario esclarecer dicho aspecto en futuros estudios en el tema.

Orientador: Maria Cristina Cintra Gomes Marcondes / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-27T06:12:33Z (GMT). No. of bitstreams: 1 Miyaguti_NataliaAngelodaSilva_M.pdf: 7149513 bytes, checksum: e738b40c2027a8507e7b5ae2e65321e8 (MD5) Previous issue date: 2015 / Resumo: O Resumo poderá ser visualizado no texto completo da tese digital / Abstract: The Abstract is available with the full electronic digital document / Mestrado / Fisiologia / Mestra em Biologia Funcional e Molecular

The master's thesis is elaborated on the basis of the project of the Sport and Health Center Olomouc. The project consists of two main buildings – the object of NH Hotel and the Sports Center Omega. The hotel also includes a conference center with three conference halls and covered parking. The object of Omega Sports Center is composed of sports halls for squash, badminton and tennis, along with changing rooms, wellness area and operational background of the object itself. The sports center also incorporates outdoor tennis courts and an underground tunnel connecting the Omega center and the NH Hotel. This thesis deals with the civil technological project of the building site and involves mainly the technical report of civil technological project, the study of realization of the main technological stages of the building object, the project of organization of construction, time schedule of aforementioned two main buildings, the technological standard with test and execution plans for the execution of underground construction by the impermeable concrete technology and for execution of variant solution of tennis hall roofing. Further, a comparison of the alternative roofing technology with current used roofing technology is performed, including the drawing documentation of new roofing alternative.

Syfte: Syftet med studien var att genom en litteraturstudie undersöka om tillskott av omega-3 har någon positiv påverkan på torra ögon och ögats främre delar. Kan denna fleromättade fettsyra lindra symtomen samt de kliniska tecknen av torra ögon? Metod: Artiklarna i litteraturstudien baserades på tidigare kliniska studier och vetenskapliga publikationer. De sökmotorer som användes var PubMed och Web of Science, sökningarna utfördes mellan 2020-03-30 och 2020-04-15. För att göra urvalsprocessen sattes inklusionskriterier och exklusionskriterier upp. Begränsningarna var att artiklarna skulle finnas tillgängliga i fulltext och vara publicerade från år 2015-2020. Sökorden som användes var “dry eye + omega” och “dry eye and omega”. Litteraturstudier/reviews exkluderades samt studier med färre än 50 deltagare. Utifrån resultatet av sökningarna valdes de fem mest relevanta artiklarna ut för att ingå i studien. Resultat: Studierna involverade totalt 2569 deltagare. Tillskotten som användes i studierna var omega-3 i olika sammansättningar. De subjektiva mätningarna gjordes med Ocular Surface Disease Index (OSDI) och Dry Eye Questionnaire and Scoring System (DESS) och visade statistiskt signifikant förbättring på symtompoäng i tre av fem studier. De objektiva mätningarna visade statistiskt signifikant förbättring på bland annat TBUT i fyra av fem studier och Schirmertest i två av fem studier. Slutsats: Det finns en positiv effekt på torra ögon, torra ögonsymtom och främre ytan av ögat med ett dagligt tillskott av omega-3-fettsyror, men en viss placeboeffekt kan inte uteslutas. Fler studier med fler deltagare under en längre period krävs för att fastställa den optimala dosen, behandlingsperioden samt sammansättningen av tillskottet av omega-3. / The aim of this study was through a literature review, investigate whether a dietary supplement of omega-3 has a positive effect on dry eye symptoms and the anterior surface of the eye. Can this polyunsaturated fatty acid relieve the symptoms and the clinical signs of dry eyes? The articles included in the literature study were based on previous clinical studies and scientific publications. The search engines used were PubMed and Web of Science. The searches were conducted between 2020-03-30 and 2020-04-15. Inclusion criteria and exclusion criteria were determined in advance. The restrictions were that the articles should be available in full text and be published from 2015-2020. The keywords used were “dry eye + omega” and “dry eye and omega”. Other literature reviews were excluded as well as studies with fewer than 50 participants in the randomized clinical trials (RCTs). Based on the results on the searches, 30 articles were selected that related to the topic dry eyes and omega-3. Subsequently, the articles abstracts were reviewed, and the least relevant articles were excluded. The remaining 13 articles were read in more detail and of these, the 5 most relevant articles were selected to be included in the study. The five selected studies involved a total of 2569 participants. The supplements used in the studies contained omega-3 in various compositions. The subjective measurements were made using the Ocular Surface Disease Index (OSDI) and the Dry Eye Questionnaire and Scoring System (DESS) and showed statistically significant improvement in symptom scores in three out of five studies. The objective clinical tests showed statistically significant improvement on for example TBUT in four out of five studies and Schirmer’s test in two out of five studies. The conclusion is that there is a positive effect on dry eyes, dry eye symptoms and the ocular surface of the eye with a daily supplement of omega-3 fatty acids, however a placebo effect cannot be ruled out. More studies with more participants over a longer period of time are required to determine the optimal dose, treatment period and composition of the supplement of omega-3.