Supplementing Diet with Blackberry Extract Causes a Catabolic Response with Increments in Insulin Sensitivity in Rats

Abstract

Blackberry (Rubus sp.) fruit has a high content of anthocyanins, but its health benefits have not been sufficiently explored in healthy individuals. Thus, the aim of the study was to determine the effects of blackberry extract on lipid and glucose variables in female and male rats. Sprague Dawley rats were given a standard pellet (SD) or cafeteria (CD) diet supplemented (SD+R and CD+R) or not with Rubus extract for 80 days. Female rats given SD+R had lower body and liver weights than SD females; both sexes given SD+R showed lower plasma glucose and insulin, higher plasma NEFA, glycerol and 3-hydroxybutyrate, and higher liver concentration of triacylglycerols than SD rats. The homeostasis model of insulin resistance (HOMA) was lower in SD+R rats than in SD rats, but higher in CD rats. No effects of Rubus extract were observed in CD rats. In conclusion, Rubus extract, in rats given SD, decreased glycemia and increased insulin sensitivity. It also increased lipid breakdown in adipose tissue. The effects were greater in females than in males. No effect was seen in rats given CD, probably as a result of their high insulin resistance.

A Selective Role of Dietary Anthocyanins and Flavan-3-ols in Reducing the Risk of Type 2 Diabetes Mellitus: A Review of Recent Evidence

“…Xing et al [71] also observed increased insulin sensitivity consistent with increased AMPK phosphorylation in white adipose tissue of obese mice supplemented with 5% freeze dried raspberry powder for 12 weeks. In another study, 80 days supplementation of blackberry extract in standard rat diet compared to standard diet alone increased insulin sensitivity, and decreased concentrations of glucose and insulin; however, the changes were greater in female than in male rats [72]. Tani et al performed an intraperitoneal glucose tolerance test in six-week-old male Sprague–Dawley rats after oral administration of blackcurrant extract vs. control diet (no blackcurrant) and reported increased glucagon like peptide-1 (GLP-1) and insulin secretion [73].…”

LC-Q-TOF-MS Characterization of Polyphenols from White Bayberry Fruit and Its Antidiabetic Effect in KK-Ay Mice

“… 11 , 12 As to blackberry, it showed a strong inhibitory effect on α-glucosidase that is linked to T2D and alleviated glycemia and IR in rats, demonstrating its potential benefit on the control or management of T2D. 13 , 14 All of these berries are rich in anthocyanins, which were known as the major functional ingredients due to their great antidiabetic potential.…”

Evaluating Traditional Chinese Medicine and Herbal Products for the Treatment of Gestational Diabetes Mellitus

“…Other members of the same genus (listed in Table 2) also have documented hypoglycemic effect. For example, in rats fed a standard diet, Rubus fruticosus extract increased lipolysis of adipose tissue and enhanced insulin sensitivity, which was more pronounced in females [38]. In diabetic rats induced by either alloxan or streptozotocin, oral administration of Rubus fruticosus aqueous extract elicited hypoglycemic effects [39, 40].…”