Antioxidant, anti-inflammatory and beneficial metabolic effects of botryosphaeran [(1→3)(1→6)-β-d-glucan] are responsible for its anti-tumour activity in experimental non-obese and obese rats bearing Walker-256 tumours.

Botryosphaeran, a (1→3)(1→6)-β-d-glucan, presents several beneficial activities, such as antiproliferative, hypoglycemic and antitumoural activities. This study evaluated the effects of botryosphaeran on oxidative stress, inflammation and metabolic activities in Walker-256 tumour-bearing non-obese and obese rats. Wistars rats were divided into four groups: control tumour (CT); control tumour + botryosphaeran (CTB); obese tumour (OT), and obese tumour + botryosphaeran (OTB). In ninth week, obese and non-obese rats were inoculated with 1 × 10 7 Walker-256 tumour cells and treated with botryosphaeran (30 mg/kg/d for 15 days). In 11th week, the following parameters were evaluated glycogen, glucose and lactate levels, pro-oxidant (TBARS) and antioxidant markers (superoxide dismutase [SOD]; catalase [CAT]; glutathione-S-transferase [GST]; reduced glutathione [GSH]; vitamin C) and cytokines. Obesity presented oxidative stress and inflammation, as demonstrated by high levels of TBARS, SOD and TNF-α, and lower levels of CAT, GSH and interleukin-10 (IL-10). Botryosphaeran significantly decreased TBARS and TNF-α and increased GST, GSH, vitamin C and IL-10 in the liver; increased SOD and vitamin C in tumour tissue; decreased TBARS in adipose tissue, and notably decreased the levels of glycogen and lactate in the tumour of CTB rats. Botryosphaeran promoted significant antioxidant, anti-inflammatory, and beneficial metabolic effects in Walker-256 tumour-bearing non-obese and obese rats, which contributed to its antitumour activity.