'Saba' banana (Musa acuminata x balbisiana BBB Group) peel pectin supplementation improves biomarkers of obesity and associated blood lipid disorders in obese hypercholesterolemic mice.

'Saba' banana peel contains significant amounts of pectin but with very limited commercial use. To increase its value, the present study investigated the effect of 'saba' peel pectin (SPP) on biomarkers of obesity and associated blood lipid disorders in vivo and identified its potential mechanism via in vitro lipid lowering assays. ICR male mice were induced with obesity and hypercholesterolemia using 45% high fat diet (HFD) for three weeks. The mice were then randomly allocated to four groups fed various diets ad libitum for nine weeks as follows: (1) normal diet (ND), (2) high-fat diet (HFD), (3) HFD with 10% w/w commercial citrus pectin (HFD-CCP), and (4) HFD with 10% w/w SPP (HFD-SPP). For the in vitro study, lipid lowering assays were carried out using published protocols with some modifications. Results showed that the mean endline body weight of HFD-CCP and HFD-SPP were significantly lower than HFD group despite having comparable feed intake. The pectin-supplemented groups also had lower blood total cholesterol than HFD group. Necropsy results showed no significant treatment-related difference in the relative organ weights, except for the liver of HFD group being pale, enlarged, and heavier than the other mice groups. This is consistent with the microscopic observations of liver sections from HFD-CCP and HFD-SPP which had occasional fat deposits only whereas HFD group showed mild necrosis and fat infiltration. In terms of body fat, the adiposity index was significantly lower among HFD-SPP and HFD-CCP than the HFD group, with both pectin-supplemented groups showing lesser extent of increase in adipocyte diameter. Meanwhile, HFD-CCP and HFD-SPP groups were significantly comparable in terms of body weight, blood lipids, organ and adipose tissue weights, adiposity index, and liver morphology. In vitro assays revealed that SPP had significantly higher cholesterol and bile acid binding capacities at 60 µg/mL and 20 µg/mL, respectively than CCP and bile acid-binding drug, cholestyramine. These showed that SPP supplementation improves biomarkers of obesity and associated blood lipid disorders at par with commercially-available citrus pectin possibly via cholesterol and bile acid binding pathways, suggesting that SPP may be a potential functional ingredient with anti-obesity and anti-hypercholesterolemic properties.

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

Red raspberry fruit intake was investigated on obese diabetic (db/db) mice for 8weeks. 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.