Osteoporosis, characterized
by a gradual decrease in the number
of osteoblasts and a gradual increase in bone resorption of osteoclasts
in bone tissue, is a global chronic disease, which severely impairs
the quality of life of the elderly. Therefore, it is extremely urgent
to study the prevention and treatment of osteoporosis. It has been
reported that anthocyanins can regulate bone metabolism and prevent
osteoporosis. Cyanidin-3-O-glucoside (C3G), the most common type of anthocyanin in
nature, widely exists in a variety of vegetables and fruits. Although
it has been shown that C3G has multiple effects on osteoclasts, its
impact(s) and underlying mechanism(s) on osteoblasts are still not
clear. Here, we evaluated the effect of C3G on cell proliferation
and differentiation of osteoblasts (extracted from the hip joint of
patients with osteoporosis) and MC3T3-E1 (a kind of osteoblast cell
line from mice). We also test the ability of osteoblasts to mineralize
after C3G treatment. To find the underlying mechanism of the above
effects, we further evaluated the role of the ERK signaling pathway
in C3G regulation of osteoblasts. The results showed that C3G treatment
enhanced osteoblast proliferation rate, osteoblast mineralization
points, the mRNA levels and protein expression levels of OC (osteocalcin),
and the level of ERK phosphorylation, which could be blocked by pretreatment
with ERK signaling pathway inhibitor. The above results not only indicate
that the ERK pathway was involved in C3G regulation of osteoblast
differentiation but also provide strong suggestive evidence that osteoblasts
may be promising targets in preventive and therapeutic strategies
for osteoporosis.