Tag Archives: animal

Dried Plum Decreases Osteoclast Activity

Abstract

Dried plum polyphenols inhibit osteoclastogenesis by downregulating NFATc1 and inflammatory mediators.

Dried plums and their polyphenols have been shown to suppress bone resorption by downregulating receptor activator NF-kappaB ligand (RANKL). Due to the anti-inflammatory and antioxidant properties of these compounds, this study was designed to investigate whether dried plum polyphenols exert additional, more direct effects on osteoclasts and their precursors. RAW 264.7 macrophages were used as a model to study osteoclast precursors and osteoclast differentiation and activity. Under inflammatory conditions induced by lipopolysaccharide (LPS), polyphenols extracted from dried plum (10, 20, and 30 microg/mL) downregulated osteoclast precursor cyclooxygenase expression and nitric oxide (NO) by inhibiting inducible NO synthase. NO and tumor necrosis factor (TNF)-alpha were also suppressed in the presence of RANKL during osteoclastogenesis by the polyphenols. Increased TNF-alpha production in response to oxidative stress, but not LPS, was decreased over time. As expected, LPS and H2O2 significantly increased the number of tartrate-resistant acid phosphatase-positive cells by 127% and 30%, respectively. Dried plum polyphenols decreased osteoclast differentiation under normal as well as inflammatory and oxidative stress conditions, coincident with the suppression of the transcription factor, nuclear factor for activated T cells (NFATcl). These inhibitory effects on osteoclastogenesis were confirmed in primary bone marrow cultures. Resorption pit formation was decreased to a similar extent as osteoclast differentiation, suggesting that dried plum polyphenols primarily affect osteoclast differentiation as opposed to activity. Our data demonstrate that dried plum polyphenols directly inhibit osteoclastogenesis, leading to a decrease in osteoclast activity, by downregulating NFATc1 and inflammatory mediators.

Bu SY, Lerner M, Stoecker BJ, Boldrin E…
Calcif. Tissue Int. Jun 2008
PMID: 18509698

Tocotrienols More Effective Than Calcium?

Abstract

Palm tocotrienol supplementation enhanced bone formation in oestrogen-deficient rats

Postmenopausal osteoporosis is the commonest cause of osteoporosis. It is associated with increased free radical activity induced by the oestrogen-deficient state. Therefore, supplementation with palm-oil-derived tocotrienols, a potent antioxidant, should be able to prevent this bone loss. Our earlier studies have shown that tocotrienol was able to prevent and even reverse osteoporosis due to various factors, including oestrogen deficiency. In this study we compared the effects of supplementation with palm tocotrienol mixture or calcium on bone biomarkers and bone formation rate in ovariectomised (oestrogen-deficient) female rats. Our results showed that palm tocotrienols significantly increased bone formation in oestrogen-deficient rats, seen by increased double-labeled surface (dLS/Bs), reduced single-labeled surface (sLS/BS), increased mineralizing surface (MS/BS), increased mineral apposition rate (MAR), and an overall increase in bone formation rate (BFR/BS). These effects were not seen in the group supplemented with calcium. However, no significant changes were seen in the serum levels of the bone biomarkers, osteocalcin, and cross-linked C-telopeptide of type I collagen, CTX. In conclusion, palm tocotrienol is more effective than calcium in preventing oestrogen-deficient bone loss. Further studies are needed to determine the potential of tocotrienol as an antiosteoporotic agent.

Soelaiman IN, Ming W, Abu Bakar R, Hashnan NA…
Int J Endocrinol. 2012
PMID: 23150728

Even though this is an animal study, it is impressive that tocotrienols were more effective than calcium.