In vivo Antiosteoporotic Activity of a Fraction of Dioscorea spongiosa and its Constituent, 22-O-Methylprotodioscin

Abstract

The antiosteoporotic activity of the 90 % EtOH fraction of the water extract of rhizomes of Dioscorea spongiosa and methylprotodioscin, its major constituent, were examined in the model of postmenopausal bone loss using ovariectomized (OVX) rats or mice. After 6 weeks treatment, the proximal tibia of rats or mice and the distal femora of mice were scanned by peripheral quantitative computed tomography (pQCT). Both the 90 % EtOH fraction (100 mg/kg/d) and methylprotodioscin (50 mg/kg/d) significantly inhibited bone loss in bone mineral content (BMC) and bone mineral density (BMD) in total, cancellous and cortical bones, and the decrease in bone strength indexes induced by OVX, without side effect on the uterus.

Abbreviations

OVX:ovariectomized

PQCT:peripheral quantitative computed tomography

EPT:estrogen replacement therapy

PTH:parathyroid hormone

E₂:17β-estradiol

BMC:bone mineral content

BMD:bone mineral density

Peoi. C:periosteal circumstance

Endo. C.:endosteal circumstance

XSSI:X-axis strength index

YSSI:Y-axis strength index

PSSI:polar-axis strength index

PTM:proximal tibiae metaphyses

DFM:distal femoral metaphyses

NEH:high dose of 90 % EtOH fraction

NEL:low dose of 90 % EtOH fraction

MPH:high dose of methyl protodioscin

MPL:low dose of methyl protodioscin

Key words

Dioscorea spongiosa - Dioscoreaceae - methylprotodioscin - osteoporosis - pQCT

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