Potential role of the antioxidant N-acetylcysteine in slowing bone resorption in early post-menopausal women: a pilot study

Bone is a highly dynamic tissue that is constantly adapting to micro-changes to facilitate movement. When the balance between bone building and resorption shifts more towards bone resorption, the result is reduced bone density and mineralization, as seen in osteoporosis or osteopenia. Current treatment strategies aimed to improve bone homeostasis and turnover are lacking in efficacy, resulting in the search for new preventative and nutraceutical treatment options. The myokine irisin, since its discovery in 2012, has been shown to play an important role in many tissues including muscle, adipose, and bone. Evidence indicate that irisin is associated with increased bone formation and decreased bone resorption, leading to reduced risk of osteoporosis in post-menopausal women. In addition, low serum irisin levels have been found in individuals with osteoporosis and osteopenia. Irisin targets key signaling proteins, promoting osteoblastogenesis and reducing osteoclastogenesis. The present review summarizes the existing evidence regarding the effects of irisin on bone homeostasis.

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Changes in serum somatomedin and growth hormone concentrations after 3 weeks oestrogen substitution in post-menopausal women; a pilot study

Acta Endocrinologica ◽

10.1530/acta.0.1060527 ◽

1984 ◽

Vol 106 (4) ◽

pp. 527-531 ◽

Cited By ~ 25

Author(s):

S. A. Duursma ◽

J. W. J. Bijlsma ◽

H. C. Van Paassen ◽

S. C. van Buul-Offers ◽

A. Skottner-Lundin

Keyword(s):

Growth Hormone ◽

Pilot Study ◽

Serum Levels ◽

Preventive Effect ◽

Positive Role ◽

Menopausal Women ◽

The Mean ◽

Post Menopausal ◽

Serum Gh

Abstract. Oestrogens have a preventive effect on bone loss in post-menopausal women; however, little is known about their mechanism of action. The aim of this study was to investigate the changes in somatomedins (SM) and growth hormone (GH) concentrations in serum in postmenopausal women after 3 weeks of substitution with 20 μg ethinyloestradiol. A significant decrease was observed in the mean serum levels of SM. measured by bioassay (0.66 ± 0.07 vs 0.38 ± 0.07. P < 0.01), radioimmunoassay (0.62 ± 0.08 vs 0.34 ± 0.03, P < 0.01) and radioreceptorassav (1.14 ± 0.11 vs 0.90 ± 0.09, P < 0.01). The mean serum GH concentration increased (9.4 ± 3.2 vs 16.5 ± 4.6, P < 0.01). A positive role of SM and GH in the changes of bone metabolism after oestrogen substitution in post-menopausal women is discussed.

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Steroid Formation in Osteoblast-Like Cells

Journal of International Medical Research ◽

10.1177/030006059802600101 ◽

1998 ◽

Vol 26 (1) ◽

pp. 1-12 ◽

Cited By ~ 29

Author(s):

H Saito ◽

T Yanaihara

Keyword(s):

Cell Lines ◽

Messenger Ribonucleic Acid ◽

Steroid Sulphatase ◽

Menopausal Women ◽

Hormonal Action ◽

Polymerase Chain ◽

Post Menopausal ◽

Receptor Mrnas

For preventing the reduction of bone mass in post-menopausal women, oestrogen replacement is known to be useful and the importance of sex steroids in bone metabolism in both sexes is well established. The presence of steroid-converting-enzyme activities in various osteoblast and osteoblast-like cells has been demonstrated using in vitro culture systems. In the present study, we assessed the expression of messenger ribonucleic acid (mRNA) for aromatase, steroid sulphatase, 5α-reductase, 17β-hydroxysteroid dehydrogenase (17β-HSD) and 3β-HSD by reverse transcription-polymerase chain reaction in the human osteoblast-like cell lines, MG 63 and HOS. Oestrogen, androgen and progesterone receptor mRNAs were also measured. Expression of mRNA for these enzymes and receptors was found in both cell lines without induction. From these and previous findings, we conclude that osteoblast-like cells have the capacity to form biologically potent oestrogens and androgens from peripheral circulating steroids. This may indicate an important role of bone in facilitating hormonal action.

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