Carotenoids and polyphenols improve bone health parameters in human osteoclasts, osteoblasts and in a 3D model of bone

In normal bone, there is constant construction and destruction of bone matrix called bone remodeling. Bone is reabsorbed by osteoclasts, after which new bone is deposited by osteoblasts. During osteoporosis there is excessive bone resorption and inadequate formation of new bone leading to thinning of the bone matrix. Several clinical and epidemiological studies show that some phytonutrients have beneficial effect in osteoporosis. The aim of the current study was to examine the effect of various phytonutrients on osteoblasts osteoclasts and determine whether combinations of dietary derived compounds improve parameters of bone health and to examine the effect of these compounds on a 3D model of mineralized bone. We used human primary osteoblasts and examined alkaline phosphatase (ALP) levels as a marker for osteoblasts activity. Treatment of osteoblasts during osteogenic differentiation with carnosic acid, curcumin, lutein or lycopene led to increased ALP levels, this compounds also increased runt-related transcription factor 2 (Runx2) protein levels in osteoblasts that examined by W.B. Osteoclast differentiation was studied in monocytes isolated from human blood and treated with M-CSF and RANKL by measuring Tartrate Resistant Acid Phosphatase (TRAP) and by Western blotting and Real Time PCR. Carnosic acid, curcumin lutein and lycopene and their Combinations inhibit human osteoclast differentiation. Similar effects were seen in a 3D model of mineralized bone containing osteoblasts and osteoclasts. Our findings suggest that carotenoids and polyphenols inhibit osteoclast differentiation and induce osteoblast differentiation. We posit that the outcome of our study will be useful for reducing the health burden of osteoporosis.