CalciumNEW2026-09

Sigma Anti-bonding Calcium Attenuates Ovariectomy-Induced Bone Loss by Preserving Trabecular Microarchitecture and Suppressing Osteoclastogenesis.

Oh Yena, Yoo Byong Chul, Moon Sohee, Rhee Sun Moo et al. — Calcified tissue international

Summary

This study investigated a special type of calcium, called sigma anti-bonding calcium (SAC), and its effects on bone health. Researchers found that SAC helped reduce bone loss in mice that had their ovaries removed, a common model for post-menopausal bone weakening. It did this by protecting the internal structure of bones and slowing down the cells that break down bone, suggesting SAC might be a promising area for future research in preventing bone loss.

AI-generated summary — read the original

Key points

Sigma anti-bonding calcium (SAC) is a special form of calcium investigated for bone health.
In a mouse study, SAC helped reduce bone loss caused by estrogen deficiency.
It worked by protecting bone structure and slowing down bone-resorbing cells.
More research is needed, especially comparing SAC to standard calcium supplements.

What the study looked at

This study aimed to investigate whether a specific type of calcium, called sigma anti-bonding calcium (SAC), could help prevent bone loss, particularly that linked to estrogen deficiency, which is common in post-menopausal osteoporosis. Researchers used female mice whose ovaries were removed to mimic the estrogen deficiency seen in menopause. These mice were given SAC orally for 13 weeks. The study also included lab experiments using cells to understand how SAC affects bone-breaking cells (osteoclasts). The study found that SAC helped preserve the internal structure of bones and maintained bone density in the mice. It also reduced the activity of cells that break down bone. In lab tests, SAC directly suppressed the formation of these bone-breaking cells. These findings suggest SAC may help protect against bone loss by both maintaining bone structure and reducing bone breakdown. However, the study notes that comparisons with conventional calcium are still needed.

Dietary takeaway

While this study suggests a specific form of calcium might help bone health, it's important to remember it was conducted in mice and lab cells, not humans. For now, focusing on a balanced diet rich in calcium from foods like dairy products, leafy greens, and fortified foods remains the best strategy for bone health. Always consult a healthcare professional before considering new supplements, as one study alone isn't enough to make definitive recommendations.

Abstract

Estrogen deficiency-induced osteoporosis is characterized by increased bone resorption and progressive deterioration of trabecular microarchitecture, leading to skeletal fragility. This study investigated the effects of sigma anti-bonding calcium (SAC), a formulation designed to enhance ion release, in an ovariectomized (OVX) mouse model and in RANKL-induced osteoclastogenesis in vitro. Female mice underwent OVX and received oral SAC (100 or 200 mg/kg/day) for 13 weeks following surgery. Body and major organ weights were monitored during the experimental period. SAC administration did not significantly affect body or major organ weights under the conditions examined. Micro-computed tomography demonstrated that SAC attenuated OVX-induced trabecular deterioration, as evidenced by preservation of bone mineral density (BMD), partial restoration of trabecular number, and reduction of structural model index, whereas trabecular thickness and separation were minimally affected. Histological analysis further confirmed preservation of trabecular bone area in SAC-treated mice, whereas marrow adiposity assessed by Oil Red O staining was not markedly altered. Serum analysis revealed that SAC significantly reduced OVX-induced elevation of C-terminal telopeptide of type I collagen (CTX), while formation-associated markers did not show consistent recovery. In vitro, SAC suppressed RANKL-induced osteoclast differentiation in RAW264.7 cells without significantly affecting cell viability at the concentrations examined. SAC dose-dependently reduced the mRNA expression of osteoclast-related genes, including TRAP, NFATc1, Ctsk, and Atp6v0d2, and attenuated NFATc1 protein induction. SAC treatment was associated with reduced RANKL-stimulated p38 phosphorylation without changes in total p38 expression and with decreased MITF protein expression. Collectively, these findings indicate that SAC attenuates estrogen deficiency-associated trabecular bone deterioration and suppresses osteoclast differentiation, accompanied by changes in p38 phosphorylation and NFATc1 and MITF expression. These findings support further investigation of SAC as a potential adjunctive approach for attenuating estrogen deficiency-associated bone loss; however, comparative studies with conventional calcium formulations are required to determine whether the observed effects are specific to SAC.

View on PubMed →DOI: 10.1007/s00223-026-01605-8