Antitumor and anti-cachectic effects of shark liver oil and fish oil: comparison between independent or associative chronic supplementation in Walker 256 tumor-bearing rats.

BACKGROUND: Shark liver oil (SLOil) and fish oil (FOil), which are respectively rich in alkylglycerols (AKGs) and n-3 polyunsaturated fatty acids (PUFAs), are able to reduce the growth of some tumors and the burden of cachexia. It is known that FOil is able to reduce proliferation rate and increase apoptotic cells and lipid peroxidation of tumor cells efficiently. However, there are few reports revealing the influence of SLOil on these parameters. In the current study, effects of FOil chronic supplementation on tumor growth and cachexia were taken as reference to compare the results obtained with SLOil supplementation. Also, we evaluated if the association of SLOil and FOil was able to promote additive effects. METHODS: Weanling male Wistar rats were divided into 4 groups: fed regular chow (C), supplemented (1 g/kg body weight) with SLOil (CSLO), FOil (CFO) and both (CSLO + FO). After 8 weeks half of each group was inoculated with Walker 256 cells originating new groups (W, WSLO, WFO and WSLO + FO). Biochemical parameters of cachexia, tumor weight, hydroperoxide content, proliferation rate and percentage of apoptotic tumor cells were analysed. Fatty acids and AKG composition of tumor and oils were obtained by high performance liquid chromatography and gas chromatography - mass spectrometry, respectively. Statistical analysis was performed by unpaired t-test and one-way ANOVA followed by a post hoc Tukey test. RESULTS: Fourteen days after inoculation, SLOil was able to restore cachexia parameters to control levels, similarly to FOil. WSLO rats presented significantly lower tumor weight (40%), greater tumor cell apoptosis (~3-fold), decreased tumor cell proliferation (35%), and higher tumor content of lipid hydroperoxides (40%) than observed in W rats, but FOil showed more potent effects. Supplementation with SLOil + FOil did not promote additive effects. Additionally, chromatographic results suggested a potential incorporation competition between the n-3 fatty acids and the AKGs in the tumor cells' membranes. CONCLUSIONS: SLOil is another marine source of lipids with similar FOil anti-cachectic capacity. Furthermore, despite being less potent than FOil, SLOil presented significant in vivo antitumor effects. These results suggest that the chronic supplementation with SLOil may be adjuvant of the anti-cancer therapy.

Anaerobic exercise reduces tumor growth, cancer cachexia and increases macrophage and lymphocyte response in Walker 256 tumor-bearing rats.

Here, we investigated the effect of jump exercise on tumor growth, cancer cachexia, lymphocyte proliferation and macrophage function in Walker 256 tumor-bearing rats. Male Wistar rats (60 days) were divided into sedentary (C) and exercised (E) groups. Jump training consisted of six sets of 10 jumps in water with overload of 50% of body mass with 1 min of resting, four times per week for 8 weeks. After 6 weeks of training, half of each group was inoculated with 2 x 10(7) cells of Walker 256 tumor. Sedentary tumor-bearing and exercised tumor-bearing are referred to as T and TE, respectively. Tumor weight in the T group was 25 g. These animals display loss of weight, hypertriacylglycerolemia, hyperlacticidemia, depletion of glycogen stores and increase in PIF expression. Jump exercise (TE) induced a significant lower tumor weight, preserves liver glycogen stores, partly prevented the hypertriacylglycerolemia, hyperlacticidemia and, prevented the fall in body weight and reduced PIF expression. Lymphocyte was increased by tumor burden (T) and was higher by including exercise (TE). The same was observed regarding phagocytosis and lysosomal volume. Anaerobic exercise decreases tumor growth, cancer cachexia and increases innate and adaptative immune function.

Neutrophil response of anaerobic jump trained diabetic rats.

This paper investigated the effect of jump training on blood biochemical parameters and neutrophil responses of diabetic rats. Male Wistar rats were divided into control, trained, diabetic and trained-diabetic groups. Diabetes was induced by i.v. injection of streptozotocin. Jump training consisted of six sets of ten jumps in water with overload of 50% of body mass with 1-min of resting, four times per week during 6 weeks. Plasma glucose, lactate, triacylglycerol and total cholesterol concentrations, differential leukocyte count, phagocytosis and anion superoxide production by neutrophils were evaluated. Diabetes caused hyperglycemia, hypertriacylglycerolemia, and body weight loss. Physical training reversed hypertriacylglycerolemia. Jump training increased phagocytosis and anion superoxide production by blood neutrophils from trained and trained-diabetic rats. Neutrophilia and lymphocytopenia occur in diabetic and trained-diabetic rats. Anaerobic jump training in diabetic rats reduced hypertriacylglycerolemia and increased neutrophil anion superoxide production. Phagocytosis was not altered in trained-diabetic rats.