Onion decreases the ovariectomy-induced osteopenia in young adult rats.
It has been suggested that fruit and vegetable consumption are associated with good bone health. Onion, in particular, has been verified in its efficacy in bone resorption activity. In this study, we further investigated the effects of an onion-containing diet on ovariectomy-induced bone loss using methods of serum marker assay, histomorphometric analysis and biomechanical tests. Sixty-four female Wistar rats (14-week-old) with sham operations or ovariectomy were assigned to 6 groups: CON, sham-operated control group; OVX, ovariectomized group; ALN, ovariectomized rats treated with alendronate (1 mg/kg/day, p.o.); and 3% ON, 7% ON and 14% ON, ovariectomized rats fed with diets containing 3%, 7% and 14% (wt/wt) onion powder, respectively. Animals were sacrificed after a six-week treatment course. In the serum marker assay, alendronate and all three onion-enriched diets significantly decreased serum calcium level (p<0.05). Both 14% ON group and the ALN group even showed similarly lower level of serum osteocalcin (p<0.05), suggesting a down-regulation of bone turnover. The histomorphometric analysis showed that ovariectomy markedly decrease bone trabeculae. The ALN and 14% ON rats were 80% and 46% higher, respectively, in BV/TV than the OVX rats (p<0.05), and the rats fed with onion-enriched food showed a lesser ovariectomy-induced bone loss in a dose-dependent manner. Additionally, both ALN and 14% ON groups had significantly more trabecular number, less separated trabeculae, and fewer osteoclasts (p<0.05), but the protective efficacy from the 14% onion-enriched diet was slightly inferior to that of alendronate. Ovariectomy also significantly decreased tissue weight and biomechanical strength in the OVX group (p<0.05). The ALN and 14% ON groups equivalently showed a lesser decrease in tissue weight, though the difference was not significant. On the other hand, both the ALN and 14% ON groups represented similar biomaterial properties of femurs, and both reduced the ovariectomy-induced decrease in bending load and bending energy (p<0.05). The present study further verified that an onion-enriched diet could counteract ovariectomy-induced bone loss and deterioration of biomechanical properties.
Huang
Tsang-Hai
TH
Institute of Physical Education, Health and Leisure Studies, National Cheng-kung University, No. 1, University Road, Tainan City 701, Taiwan.
Mühlbauer
Roman C
RC
Tang
Chih-Hsin
CH
Chen
Hsiun-Ing
HI
Chang
Guan-Liang
GL
Huang
Yi-Wei
YW
Lai
Yu-Ting
YT
Lin
Hsin-Shi
HS
Yang
Wei-Ting
WT
Yang
Rong-Sen
RS
D019386:Alendronate / Q000494:pharmacology; D000818:Animals; D015415:Biomarkers / Q000097:blood; D050071:Bone Density Conservation Agents / Q000494:pharmacology*; D001851:Bone Diseases, Metabolic; D001842:Bone and Bones / Q000033:anatomy & histology / Q000187:drug effects* / Q000502:physiology; D004032:Diet; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D008297:Male; D019697:Onions / Q000737:chemistry*; D010052:Ovariectomy; D010936:Plant Extracts / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar
D015415:Biomarkers; D050071:Bone Density Conservation Agents; D010936:Plant Extracts; D019386:Alendronate