Chemical structures of curcumin (1), demethoxycurcumin (2), and bis-demethoxycurcumin (3).

Effect of two months of curcuminoid-containing turmeric extracts on bone mineral density (BMD) and bone volume fraction (BV/TV) was assessed by dual-energy x-ray absorptiometry (DXA), and micro-computerized tomography (μCT), respectively. Three-month old female Sprague Dawley rats (n = 9–11 animals/group) were ovariectomized (OVX) and treated ip for two months with vehicle, a complex turmeric fraction (41% curcuminoids by weight), or a curcuminoid-enriched extract of turmeric (94% curcuminoids by weight). Both extract doses were normalized to curcuminoid content (60 mg/kg, three times per week). Statistical significance was determined by ANOVA with Student-Newman-Keuls post hoc test. Values that do not share the same superscript are significantly different at p < 0.05 for the respective timepoint. (A) After two months of treatment (d 56), BMD was significantly decreased in OVX-vehicle treated animals relative to sham-vehicle. Complex turmeric treatment had no effect on BMD relative to OVX-vehicle treated animals, however, treatment with curcuminoid-enriched turmeric extract significantly protected BMD, preventing 50% loss. (B) Effects of treatment on BMD were confirmed by μCT, a more sensitive measure of three-dimensional content and architecture of trabecular bone. Treatment effects on BV/TV mirrored BMD results on d 56, confirming a lack of effect of treatment with complex turmeric, and approximately 50% protection of BV/TV conferred by treatment with curcuminoid-enriched turmeric.

Parameters of trabecular morphology, (A) connectivity-density (Conn-Dens.), (B) trabecular number (Tb.N), (C) trabecular thickness (Tb.Th), and (D) trabecular spacing (Tb.Sp.) were measured by micro-computerized tomography (μCT). Three-month old female Sprague Dawley rats were ovariectomized (OVX) and treated ip for two months with vehicle, a complex turmeric fraction (41 % curcuminoids by weight), or a curcuminoid-enriched extract of turmeric (94% curcuminoids by weight). Both extract doses were normalized to curcuminoid content (60 mg/kg, three times per week). Statistical significance was determined by ANOVA with Student-Newman-Keuls post hoc test. Values that do not share the same superscript are significantly different at p < 0.05.

Effect of curcuminoid-containing turmeric extracts on bone mineral density (BMD) was assessed every two weeks by dual-energy x-ray absorptiometry (DXA). Three-month old female Sprague Dawley rats (n = 9–11 animals/group) were ovariectomized (OVX) and treated ip for two months (56 days) with vehicle, a complex turmeric fraction (41 % curcuminoids by weight), or a curcuminoid-enriched extract of turmeric (94% curcuminoids by weight). Both extract doses were normalized to curcuminoid content (60 mg/kg, three times per week). Values are expressed as mean % of sham ± SEM and statistical significance was determined by ANOVA with Student-Newman-Keuls post hoc test. Values that do not share the same superscript are significantly different at p < 0.05 for each time point.

Representative microcomputed tomography images of the trabecular architecture of the distal femur in five-month female Sprague Dawley rats after two months (56 days) of treatment with complex turmeric, curcuminoid-enriched turmeric, or vehicle alone are presented.