Cancer cachexia is a multifactorial syndrome that develops during malignant tumor growth. Changes in plasma levels of several hormones and inflammatory factors result in an intense catabolic state, decreased activity of anabolic pathways, anorexia, and marked weight loss, leading to cachexia development and/or accentuation. Inflammatory mediators appear to be related to the control of a highly regulated process of muscle protein degradation that accelerates the process of cachexia. Several mediators have been postulated to participate in this process, including TNF-α, myostatin, and activated protein degradation pathways. Some interventional therapies have been proposed, including nutritional (dietary, omega-3 fatty acid supplementation), hormonal (insulin), pharmacological (clenbuterol), and nonpharmacological (physical exercise) therapies. Omega-3 (n-3) polyunsaturated fatty acids (PUFAs), especially eicosapentaenoic acid (EPA) and docosahexaenoic acid, are recognized for their anti-inflammatory properties and have been used in therapeutic approaches to treat or attenuate cancer cachexia. In this review, we discuss recent findings on cellular and molecular mechanisms involved in inflammation in the cancer cachexia syndrome and the effectiveness of n-3 PUFAs to attenuate or prevent cancer cachexia.
We investigated the effects of oral L-glutamine (Gln) supplementation, associated or not with physical exercises, in control of glycemia, oxidative stress, and strength/power of knee muscles in elderly women. Physically active (n = 21) and sedentary (n = 23) elderly women aged 60 to 80 years were enrolled in the study. Plasma levels of D-fructosamine, insulin, reduced (GSH) and oxidized (GSSG) glutathione, iron, uric acid, and thiobarbituric acid-reactive substances (TBARs) (lipoperoxidation product), as well as knee extensor/flexor muscle torque peak and average power (isokinetic test), were assessed pre- and post-supplementation with Gln or placebo (30 days). Higher plasma D-fructosamine, insulin, and iron levels, and lower strength/power of knee muscles were found pre-supplementation in the NPE group than in the PE group. Post-supplementation, Gln subgroups showed higher levels of GSH, GSSG, and torque peak, besides lower D-fructosamine than pre-supplementation values. Higher muscle average power and plasma uric acid levels were reported in the PE + Gln group, whereas lower insulin levels were found in the NPE + Gln than pre-supplementation values. TBARs levels were diminished post-supplementation in all groups. Gln supplementation, mainly when associated with physical exercises, improves strength and power of knee muscles and glycemia control, besides boosting plasma antioxidant capacity of elderly women.
Background: Obesity can lead to a chronic systemic inflammatory state that increases the risk of cancer development. Therefore, this study aimed to evaluate the alterations in tumor non-infiltrated lymphocytes function and melanoma growth in animals maintained on a high-fat diet and/or moderate physical exercise program in a murine model of melanoma.Methods: Female mice were randomly divided into eight groups: 1) normolipidic control (N), 2) normolipidic + melanoma (NM), 3) high-fat control (H), 4) high-fat + melanoma (HM), 5) normolipidic control + physical exercise (NE), 6) normolipidic melanoma + physical exercise (NEM), 7) high-fat control + physical exercise (HE), and 8) high-fat melanoma + physical exercise (HEM). After 8 weeks of diet treatment and/or moderate physical exercise protocol, melanoma was initiated by explanting B16F10 cells into one-half of the animals.Results: Animals fed a high-fat diet presented high-energy consumption (30%) and body weight gain (H and HE vs N and NE, 37%; HM and HEM vs NM and NEM, 73%, respectively), whether or not they carried melanoma explants. Although the tumor growth rate was higher in animals from the HM group than in animals from any other sedentary group, it was reduced by the addition of a physical exercise regimen. We also observed an increase in stimulated peripheral lymphocyte proliferation and a decrease in the T-helper 1 response in the HEM group.Conclusions: The results of the present study support the hypothesis that altering function of tumor non-infiltrated lymphocytes via exercise-related mechanisms can slow melanoma progression, indicating that the incorporation of a regular practice of moderate-intensity exercises can be a potential strategy for current therapeutic regimens in treating advanced melanoma.
Lymphocytes act as regulatory and effector cells in inflammation and infection situations. A metabolic switch towards glycolytic metabolism predominance occurs during T lymphocyte differentiation to inflammatory phenotypes (Th1 and Th17 cells). Maturation of T regulatory cells, however, may require activation of oxidative pathways. Metabolic transitions also occur in different maturation stages and activation of B lymphocytes. Under activation, B lymphocytes undergo cell growth and proliferation, associated with increased macromolecule synthesis. The B lymphocyte response to an antigen challenge requires an increased adenosine triphosphate (ATP) supply derived mainly through glycolytic metabolism. After stimulation, B lymphocytes increase glucose uptake, but they do not accumulate glycolytic intermediates, probably due to an increase in various metabolic pathway ‘end product’ formation. Activated B lymphocytes are associated with increased utilization of pyrimidines and purines for RNA synthesis and fatty acid oxidation. The generation of plasmablasts and plasma cells from B lymphocytes is crucial for antibody production. Antibody production and secretion require increased glucose consumption since 90% of consumed glucose is needed for antibody glycosylation. This review describes critical aspects of lymphocyte metabolism and functional interplay during activation. We discuss the primary fuels for the metabolism of lymphocytes and the particularities of T and B cell metabolism, including the differentiation of lymphocytes, stages of development of B cells, and the production of antibodies.
Background/Objectives: Goto-Kakizaki (GK) rats exhibit insulin resistance and type 2 diabetes mellitus (T2DM) without obesity. This study explored the effects of ω-3 fatty acid supplementation on T lymphocyte polarization in Wistar (WT) and GK rats. Methods: They were administered ω-3 fatty acid-rich fish oil (FO) containing eicosapentaenoic (540 mg/g) and docosahexaenoic acids (100 mg/g) by oral gavage at 2 g/kg, thrice a week for 8 weeks. The control groups (WT CT and GK CT) received the same volume of water. The following groups were investigated: GK CT, n = 14; GK ω-3, n = 15; Wistar CT, n = 15; and Wistar ω-3, n = 11. Glucose and insulin tolerance tests (GTT and ITT) were performed. Fasting plasma insulinemia and glycemia were measured. After euthanasia, the lymphocytes were extracted from the mesenteric lymph nodes. Results: The results showed that GK rats supplemented with FO had significantly improved glucose tolerance and insulin sensitivity (kITT). It also promoted greater polarization of lymphocytes toward T regulatory (Treg) features and a reduction in Th1 and Th17 profiles. Additionally, the GK ω-3 group exhibited lower cell proliferation, decreased pro-inflammatory cytokines, and increased IL-10 levels compared to the GK control. Conclusions: In conclusion, FO supplementation benefited GK rats by improving glucose intolerance, suppressing insulin resistance, and modulating lymphocytes toward Treg polarization.