The effect of Apium Nodiflorum in experimental osteoporosis.

Treatment of osteoporosis remains a therapeutic challenge. The effect of Apium Nodiflorum extract on development of experimental osteoporosis, pain thresholds and carrageenan-induced inflammation has been studied in ovariectomized osteoporotic Wistar rats. After osteoporosis verification rats were randomized and received vehicle only, HPLC-standardized Apium extract (equal to 2.4 mg/kg Quercetin) or Genistein (2.5 mg/kg) for 8 weeks. To verify the effect of Apium on the development of osteoporosis, bone mineral density (BMD) and bone mineral content (BMC), bone histology and plasma levels of IL-6 and RANKL were measured 6 months after ovariectomy and 8 weeks after treatment with Apium extract or Genistein as comparator. Inflammatory hyperalgesia was induced by intraplantar injection of 1% Carrageenan. Apium extract and Genistein impeded the development of osteoporosis (significant differences were shown for BMC and BMD levels in drug vs. vehicle treated rats) and improved bone histology and histological score. Apium and Genistein decreased IL-6 level. Both treatments alleviated mechanical hyperalgesia, decreased exudative reaction and lowered inflammatory pain threshold. The results suggested that Apium extract could be an alternative therapy for post-menopausal osteoporosis.

Viscoelastic characteristics of in vitro vital and devitalized rat aorta and human arterial prostheses.

The arterial wall viscoelasticity plays an essential role in the vascular responsiveness to vasoactive drugs or pathologies. The aim of this investigation was to derive and compare resonance curve (RC), natural frequency (f(0)), dynamic modulus of elasticity (E'), and coefficient of viscosity (beta) of (i) vital and devitalized preparations of rat thoracic and abdominal aorta, (ii) human arterial prostheses, and to study the histomorphology of vital and devitalized rat aorta. The method of low frequency forced oscillations was employed. RC of vital preparations showed a hardening type of elasticity whereas in devitalized preparations it was of softening type. E' increased nonlinearly, f(0) decreased and beta increased linearly with equivalent intraluminal pressure (p(eqi)). Distensibility of abdominal aorta was lower than thoracic aorta. Distensibility decreased with increasing p(eqi). E', f(0), and beta increased significantly after devitalization. It was suggested that postmortem viscoelastic characteristics should not be used directly to specify the vital arteries viscoelasticity. RC of human prostheses showed a softening type of elasticity. Arterial prostheses have low circumferential distensibility with E'-values higher than reported in the literature for human arteries. The method of forced oscillations could be employed for studying the arterial wall biomechanics and viscoelasticity of arterial prostheses.