Inhibition of human in vitro osteoclastogenesis by Equisetum arvense.

OBJECTIVES: Equisetum arvense has long been used in traditional medicines to treat different disorders, including bone pathologies. In this study a hydromethanolic extract of E. arvense was assessed for its effects on human osteoclastogenesis. MATERIALS AND METHODS: Osteoclast precursors were maintained in non-stimulated and stimulated (presence of M-CSF and RANKL) conditions, or in co-cultures with osteoblasts. Cell cultures were treated with 0.00016-0.5 mg/ml of a hydromethanolic E. arvense extract. RESULTS: The extract did not affect spontaneous osteoclastogenesis. In osteoclast precursors committed to osteoclastogenesis (stimulated or co-cultured with osteoblasts), E. arvense caused dose-dependent inhibitory effect that became statistically significant at concentrations ≥0.004 mg/ml. This was observed using different osteoclast differentiation and activation markers. Cell response was associated with changes in relative contribution of MEK and NFkB signalling pathways, as well as PGE2 production. As there were differences in the response of osteoclast precursors maintained in the presence of inductive factors, or co-cultured with osteoblastic cells, it seems that E. arvense extract had the ability to modulate osteoclastogenesis, either by acting directly on osteoclast precursor cells, and/or via osteoblasts. CONCLUSIONS: Equisetum appeared to have a negative effect on human osteoclastogenesis, which is in line with its putative beneficial role in pathophysiological conditions associated with increased osteoclastic activity, and might suggest potential utility for treatment with bone regeneration strategies.

Measurement of body composition changes during hemodialysis by bioimpedance analysis.

Monitoring of fluid exchanges during hemodialysis is essential for the safety and efficacy of the procedure. Bioimpedance analysis has been used for the measurement of body compartments in many settings, but experience during hemodialysis is relatively scare. In a prospective study of 28 cases of chronic renal failure treated by long-term hemodialysis on an outpatient basis, body composition studies were done immediately before and after the dialysis session. Methods included body weight, serum albumin, hematocrit, hemoglobin, sodium and osmolality. These variables were compared with impedance (BIA) findings, namely lean body mass, body fat, total water, extra and intra-cellular water, third space, and exchangeable sodium/potassium ratio. Patients lost weight and improved hematocrit, hemoglobin, osmolality and serum sodium during the therapy, and BIA measurements were consistent with these changes. Lean body mass and body fat markedly changed along the dialysis session (respectively -24.5% and + 7.5%), and these results were out of proportion regarding known gains and losses in that period. It is concluded that BIA was useful for monitoring water fluxes during hemodialysis, but provided unreliable information about body fat and lean body mass.