Category Archives: Blueberry

Blueberry May Prevent Collagen and Bone Loss in Rat Cells


Blueberry consumption prevents loss of collagen in bone matrix and inhibits senescence pathways in osteoblastic cells.

Ovariectomy (OVX)-induced bone loss has been linked to increased bone turnover and higher bone matrix collagen degradation as the result of osteoclast activation. However, the role of degraded collagen matrix in the fate of resident bone-forming cells is unclear. In this report, we show that OVX-induced bone loss is associated with profound decreases in collagen 1 and Sirt1. This was accompanied by increases in expression and activity of the senescence marker collagenase and expression of p16/p21 in bone. Feeding a diet supplemented with blueberries (BB) to pre-pubertal rats throughout development or only prior to puberty [postnatal day 21 (PND21) to PND34] prevents OVX-induced effects on expression of these molecules at PND68. In order to provide more evidence and gain a better understanding on the association between bone collagen matrix and resident bone cell fate, in vitro studies on the cellular senescence pathway using primary calvarial cells and three cell lines (ST2 cells, OB6, and MLO-Y4) were conducted. We found that senescence was inhibited by collagen in a dose-response manner. Treatment of cells with serum from OVX rats accelerated osteoblastic cell senescence pathways, but serum from BB-fed OVX rats had no effect. In the presence of low collagen or treatment with OVX rat serum, ST2 cells exhibited higher potential to differentiate into adipocytes. Finally, we demonstrated that bone cell senescence is associated with decreased Sirt1 expression and activated p53, p16, and p21. These results suggest that (1) a significant prevention of OVX-induced bone cell senescence from adult rats can occur after only 14 days consumption of a BB-containing diet immediately prior to puberty, and (2) the molecular mechanisms underlying this effect involves, at least in part, prevention of collagen degradation.

Zhang J, Lazarenko OP, Blackburn ML, Badger TM…
Age (Dordr) Jun 2013
PMID: 22555620

Blueberry Prevents Bone Loss in Ovariectomized Rats


Blueberry prevents bone loss in ovariectomized rat model of postmenopausal osteoporosis.

The objective of the present study was to explore the bone protective role of blueberry in an ovariectomized rat model. Thirty 6-month-old female Sprague-Dawley rats were either sham-operated (Sham) or ovariectomized (Ovx) and divided into three groups: Sham, Ovx (control), Ovx+blueberry (5% blueberry w/w). After 100 days of treatment, rats were euthanized, and blood and tissues were collected. Bone mineral density (BMD) and content of whole body, right tibia, right femur and fourth lumbar vertebra were assessed via dual-energy X-ray absorptiometry. As expected, Ovx resulted in loss of whole-body, tibial, femoral, and 4th lumbar BMD by approximately 6%. Blueberry treatment was able to prevent the loss of whole-body BMD and had an intermediary effect on prevention of tibial and femoral BMD when compared to either Sham or Ovx controls. The bone-protective effects of blueberry may be due to suppression of Ovx-induced increase in bone turnover, as evident by lowered femoral mRNA levels of alkaline phosphatase, collagen type I and tartrate-resistant acid phosphatase to the Sham levels. Similarly, serum osteocalcein levels were also lower in the blueberry group when compared to the Ovx control group, albeit not significantly. In summary, our findings indicate that blueberry can prevent bone loss as seen by the increases in BMD and favorable changes in biomarkers of bone metabolism.

Devareddy L, Hooshmand S, Collins JK, Lucas EA…
J. Nutr. Biochem. Oct 2008
PMID: 18328688