Red raspberry (Rubus idaeus L.) intake decreases oxidative stress in obese diabetic (db/db) mice

- Raspberry intake and oxidative stress in hyperglycemia.
- Raspberry intake increases antioxidant defenses depleted in obesity and hyperglycemia.
- Polyphenolics-fibre in raspberry protect against obesity related oxidative stress.

Red raspberry fruit intake was investigated on obese diabetic (db/db) mice for 8 weeks. Animals fed isocaloric diets (5.3% freeze-dried raspberry, or control) were assessed for obesity-diabetes-disease risk biomarkers. Results showed that raspberry intake improved antioxidant status and lessened plasma interleukin (IL)-6 (0.3-fold of control, p < 0.1); most likely through enhancing glutathione peroxidase (GPx) activity in liver (4.3-fold of control), and in blood (2.1-fold of control). Other disease-risk biomarkers were similar between groups (p > 0.05). Plasma levels of total cholesterol (T-CHL), low density lipoprotein-cholesterol (LDL-CHL), and resistin were higher in the raspberry group. Overall, the enhanced detoxifying cell defenses exerted by raspberry intake might be due to its polyphenolics and fibre. This study demonstrates in vivo that raspberry intake, at a dose that can be achieved by human consumption, might protect against diabetes-induced oxidative stress.