Effect of oral intake of choline-stabilized orthosilicic acid on hair tensile strength and morphology in women with fine hair.

The appearance of hair plays an important role in people's overall physical appearance and self-perception. Silicon (Si) has been suggested to have a role in the formation of connective tissue and is present at 1-10 ppm in hair. Choline-stabilized orthosilicic acid ("ch-OSA") is a bioavailable form of silicon which was found to improve skin microrelief and skin mechanical properties in women with photoaged skin. The effect of ch-OSA on hair was investigated in a randomized, double blind, placebo-controlled study. Forty-eight women with fine hair were given 10 mg Si/day in the form of ch-OSA beadlets (n = 24) or a placebo (n = 24), orally for 9 months. Hair morphology and tensile properties were evaluated before and after treatment. Urinary silicon concentration increased significantly in the ch-OSA supplemented group but not in the placebo group. The elastic gradient decreased in both groups but the change was significantly smaller in the ch-OSA group (-4.52%) compared to placebo group (-11.9%). Break load changed significantly in the placebo group (-10.8%) but not in the ch-OSA supplemented group (-2.20%). Break stress and elastic modulus decreased in both groups but the change was smaller in the ch-OSA group. The cross sectional area increased significantly after 9 months compared to baseline in ch-OSA supplemented subjects but not in the placebo group. The change in urinary silicon excretion was significantly correlated with the change in cross sectional area. Oral intake of ch-OSA had a positive effect on tensile strength including elasticity and break load and resulted in thicker hair.

Partial prevention of long-term femoral bone loss in aged ovariectomized rats supplemented with choline-stabilized orthosilicic acid.

Silicon (Si) deficiency in animals results in bone defects. Choline-stabilized orthosilicic acid (ch-OSA) was found to have a high bioavailability compared to other Si supplements. The effect of ch-OSA supplementation was investigated on bone loss in aged ovariectomized (OVX) rats. Female Wistar rats (n = 58, age 9 months) were randomized in three groups. One group was sham-operated (sham, n = 21), and bilateral OVX was performed in the other two groups. OVX rats were supplemented orally with ch-OSA over 30 weeks (OVX1, n = 20; 1 mg Si/kg body weight daily) or used as controls (OVX0, n = 17). The serum Si concentration and the 24-hour urinary Si excretion of supplemented OVX rats was significantly higher compared to sham and OVX controls. Supplementation with ch-OSA significantly but partially reversed the decrease in Ca excretion, which was observed after OVX. The increase in bone turnover in OVX rats tended to be reduced by ch-OSA supplementation. ch-OSA supplementation increased significantly the femoral bone mineral content (BMC) in the distal region and total femoral BMC in OVX rats, whereas lumbar BMC was marginally increased. Femoral BMD was significantly increased at two sites in the distal region in OVX rats supplemented with ch-OSA compared to OVX controls. Total lumbar bone mineral density was marginally increased by ch-OSA supplementation. In conclusion, ch-OSA supplementation partially prevents femoral bone loss in the aged OVX rat model.

Effect of oral intake of choline-stabilized orthosilicic acid on skin, nails and hair in women with photodamaged skin.

Chronic exposure of the skin to sunlight causes damage to the underlying connective tissue with a loss of elasticity and firmness. Silicon (Si) was suggested to have an important function in the formation and maintenance of connective tissue. Choline-stabilized orthosilicic acid ("ch-OSA") is a bioavailable form of silicon which was found to increase the hydroxyproline concentration in the dermis of animals. The effect of ch-OSA on skin, nails and hair was investigated in a randomized, double blind, placebo-controlled study. Fifty women with photodamaged facial skin were administered orally during 20 weeks, 10 mg Si/day in the form of ch-OSA pellets (n=25) or a placebo (n=25). Noninvasive methods were used to evaluate skin microrelief (forearm), hydration (forearm) and mechanical anisotropy (forehead). Volunteers evaluated on a virtual analog scale (VAS, "none=0, severe=3") brittleness of hair and nails. The serum Si concentration was significantly higher after a 20-week supplementation in subjects with ch-OSA compared to the placebo group. Skin roughness parameters increased in the placebo group (Rt:+8%; Rm: +11%; Rz: +6%) but decreased in the ch-OSA group (Rt: -16%; Rm: -19%; Rz: -8%). The change in roughness from baseline was significantly different between ch-OSA and placebo groups for Rt and Rm. The difference in longitudinal and lateral shear propagation time increased after 20 weeks in the placebo group but decreased in the ch-OSA group suggesting improvement in isotropy of the skin. VAS scores for nail and hair brittleness were significantly lower after 20 weeks in the ch-OSA group compared to baseline scores. Oral intake of ch-OSA during the 20 weeks results in a significant positive effect on skin surface and skin mechanical properties, and on brittleness of hair and nails.

Comparison of the aggregation properties, secondary structure and apoptotic effects of wild-type, Flemish and Dutch N-terminally truncated amyloid beta peptides.

The Dutch (E22Q) and Flemish (A21G) mutations in the betaAPP region of the amyloid precursor protein (APP) are associated with familial forms of Alzheimer dementia. However, patients with these mutations express substantially different clinical phenotypes. Therefore, secondary structure and cytotoxic effects of the three Abeta(12-42) variants [wild-type (WT), Dutch and Flemish] were tested. At a concentration of 5 microM the aggregation of these peptides followed the order: Abeta(1-42) WT > Abeta(12-42) WT > Abeta(12-42) Flemish > Abeta(12-42) Dutch. The stability of the secondary structure of these peptides upon decreasing the trifluoroethanol (TFE) concentration in the buffer was followed by circular dichroism measurements. WT peptides progressively lost their alpha-helical structure; this change occurred faster for both the Flemish and Dutch peptides, and at higher percentages of TFE in the buffer, and was accompanied by an increase in beta-sheet and random coil content. Apoptosis was induced in neuronal cells by the Abeta(12-42) WT and Flemish peptides at concentrations as low as 1-5 microM, as evidenced by propidium iodide (PI) staining, DNA laddering and caspase-3 activity measurements. Even when longer incubation times and higher peptide concentrations were applied the N-truncated Dutch peptide did not induce apoptosis. Apoptosis induced by the full length Abeta(1-42) peptide was weaker than that induced by its N-truncated variant. These data suggest that N-truncation enhanced the cytotoxic effects of Abeta WT and Flemish peptides, which may play a role in the accelerated progression of dementia.

Characterization and functional studies of lipoproteins, lipid transfer proteins, and lecithin:cholesterol acyltransferase in CSF of normal individuals and patients with Alzheimer's disease.

We investigated the lipoprotein distribution and composition in cerebrospinal fluid (CSF) in a group of patients with Alzheimer's disease (AD) or affected by other types of dementia in comparison to non-demented controls. We found slightly decreased apolipoprotein (apo)E and cholesterol concentrations in CSF of AD patients and moderately increased apoA-I concentrations, while in patients suffering from other types of dementia the apoA-I CSF concentration was increased. ApoA-IV concentrations varied widely in human CSF, but were not associated with any clinical condition. HDL(2)-like apoE-containing lipoproteins represent the major lipoprotein fraction. In CSF of normal controls, only a minor HDL(3)-like apoA-I-containing lipoprotein fraction was observed; this fraction was more prevalent in AD patients. ApoA-II was recovered mostly in the HDL(3) density range, while apoA-IV was not associated with lipoproteins but appeared in a lipid-free form, co-localizing with LCAT immunoreactivity. Bi-dimensional analysis demonstrated pre-beta and alpha apoA-I-containing particles; apoE and apoA-II were detected only in alpha-migrating particles. ApoA-IV distributed both to pre-beta and gamma-migrating particles; the LCAT signal was co-localized in this gamma-migrating fraction. Enzymatically active LCAT was present in human CSF as well as PLTP activity and mass; no CETP mass was detected. In CSF from AD patients, LCAT activity was 50% lower than in CSF from normal controls. CSF lipoproteins induced a significant cholesterol efflux from cultured rat astrocytes, suggesting that they play an active role in maintaining the cholesterol homeostasis in brain cells.

Apoptosis induced in neuronal cells by C-terminal amyloid beta-fragments is correlated with their aggregation properties in phospholipid membranes.

A number of findings suggest that lipophilic monomeric Abeta peptides can interact with the cellular lipid membranes. These interactions can affect the membrane integrity and result in the initiation of apoptotic cell death. The secondary structure of C-terminal Abeta peptides (29-40) and the longer (29-42) variant have been investigated in solution by circular dichroism measurements. The secondary structure of lipid bound Abeta (29-40) and (29-42) peptides prepared at different lipid/peptide ratio's, was investigated by ATR-FTIR spectroscopy. Finally, the changes in secondary structure (i.e. the transition of alpha-helix to beta-sheet) of the lipid bound peptides were correlated with the induction of neurotoxic and apoptotic effects in neuronal cells. The data suggest that the C-terminal fragments of the Abeta peptide induce a significant apoptotic cell death, as demonstrated by caspase-3 measurements and DNA laddering, with consistently a stronger effect of the longer Abeta (29-42) variant. Moreover, the induction of apoptotic death induced by these peptides can be correlated with the secondary structure of the lipid bound amyloid beta peptides. Based on these observations, it is proposed that membrane bound aggregated Abeta peptides (produced locally as the result of gamma-secretase cleavage) can accumulate and aggregate in the membrane. These membrane bound beta-sheet aggregated amyloid peptides induce neuronal apoptotic cell death.