Efeitos antioxidante, anti-inflamatório e metabólico da botriosferana em animais obesos e não obesos com o tumor de Walker-256

• Autor(a) principal: Silva, Thais Pereira da
• Data de Publicação: 2021
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UFMT
• Texto Completo: http://ri.ufmt.br/handle/1/4856
• topic: Obesidade; Câncer; β-glucanas; Botriosferana; Estresse oxidativo; CNPQ::CIENCIAS DA SAUDE; Obesity; Cancer; β-glucans; Botryosphaeran; Oxidative stress

Botryosphaeran, a (1-3)(1-6)-β-D-glucan, has been described for presenting several activities, such as antimutagenic, antiproliferative, hypoglycemic, and hypocholesterolemic activity, besides demonstrating an important antitumoral effect in obese and non-obese animals with Walker-256 tumor.Thus, this study aimed to evaluate the effects of botryosphaeran on morphological changes in the tumor, liver, spleen, and small intestine in obese and non-obese animals with Walker-256 tumor, as well as to evaluate the presence of metastasis, metabolic and inflammatory parameters and the oxidative stress in these animals. Wistar rats, approximately 30 days old, were used. The animals were divided into 4 groups: Control Tumor (CT); Control Tumor Botryosphaeran (CTB); Obese Tumor (OT), and Obese Tumor Botryosphaeran (OTB). Control animals received standard diet and obese animals received hyperlipidic diet and water with sucrose. On 9th week, 1x107 Walker-256 tumor cells were inoculated in all rats of all groups, and the CTB and OTB groups received treatment with botryosphaeran (30 mg/kg b.w./day, for 15 days, from the 9th to the 11th week of experiment) and controls (CT and OT) received saline. At the end of the 11th week of the experiment, all groups were evaluated. Oxidative stress markers (TBARS; carbonylated proteins; superoxide dismutase (SOD); catalase (CAT); glutathione S transferase (GST); reduced glutathione (GSH); and vitamin C), metabolic parameters (glucose, glycogen, lactate, total protein and amino acids), cytokines (IL-1β; IL-6; IL-10 and TNF-α) and histological evaluation of tissues (spleen, liver, small intestine and tumor) were evaluated. Obesity contributed to increased TBARS levels in the OT group compared to the CT group, and increased SOD activity and TNF-α levels in liver tissue. Obesity reduced CAT, GSH, glucose, and IL-10 levels in the OT group relative to the CT group. Botryosphaeran decreased liver TBARS, lactate and TNF-α levels and TBARS and lactate levels in adipose tissue of obese rats, increased hepatic glucose, IL-10 levels, and GSH levels and GST activity in liver, as increased hepatic vitamin C levels. In tumor tissue, botryosphaeran increased SOD activity in CTB animals and vitamin C levels in OTB animals. It was also observed that all groups presented areas of coagulative tumor necrosis, and botryosphaeran was effective in reducing the area of necrosis in the CTB and OTB groups. In the liver, inflammation and hepatic steatosis were observed in all groups (CT, CTB, OT, and OTB), with hepatic steatosis being more frequent and more intense in the obese group (OT). Botryosphaeran reduced the number of animals with hepatic steatosis in the OTB group. Finally, botryosphaeran reduced the area of necrosis in the tumor tissue of CTB and OTB animals. Botryosphaeran showed a protective effect against vascular invasion in tumor tissue in CTB and OTB groups. Thus, it can be concluded that obesity contributed to oxidative stress, metabolic alterations, and inflammatory mediators, and botryosphaeran was effective in protecting the animals against tissue injury triggered by oxidative stress, due to its significant antioxidant, anti-inflammatory and beneficial metabolic effects in obese and non-obese animals with Walker-256 tumor.