Animal study: ginkgo strengthens bones

Ginkgo biloba extracts do more than just improve your cardiovascular system and delay ageing processes. According to an animal study done at the Brazilian Federal University of Juiz de Fora, published in Phytotherapy Research, gingko also makes bones stronger. A dose of ginkgo had a better effect than regular osteoporosis medicine in the Brazilian study.

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The Brazilians’ research was a follow-up to test tube studies in which researchers had exposed bone cells to ginkgo. In the test-tube studies the ginkgo made the bone-forming osteoblasts work harder. In addition, components of ginkgo extracts, the flavonoid quercetin and related kaempferol, inhibited osteoclasts, which break down bones. The researchers wanted to know whether ginkgo had the same effects on a complete organism, so they gave extracts to female mice. Older women are more susceptible to osteoporosis as their production of estradiol declines.

To stimulate osteoporosis the researchers gave some of the lab animals injections of the synthetic corticosteroid hormone dexamethasone for a month. This was the osteoporosis group. A control group was given biphosphonate fosamax in addition [the positive control group]. After thirty days the Brazilians measured the strength of the bones in the rats’ lower jaws. They looked at how firmly the rats’ teeth were still embedded in the lower jaw. They took measurements in the front of the jaw – the mesial periodontal bone support [MPBS] – and at the back of the jaw – the distal periodontal bone support [DPBS].

The results below show that the regular medicine worked. The MPBS and DPBS were higher in the positive control group. The cortical thickness of the jawbone also increased.

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The Brazilians gave other groups of rats ginkgo in addition to the osteoporosis inducing dexamethasone. The higher the dose of ginkgo, the more firmly their teeth were still planted in their jaw, front and back. See below. The effect was statistically significant at doses of 28 and 56 mg extract/kg/day. Human equivalent of the testes dose: appr. 350-700 mg/day.

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The researchers suspect that substances in ginkgo attach themselves to the beta receptor for estradiol in bone cells. Compounds that attach to the receptor have only positive effects. They make bones stronger, stimulate brain cells and inhibit the effects of estradiol that are related to the alpha receptor.

“Extracts of Ginkgo biloba may be effective in the treatment of osteoporosis”, the Brazilians conclude.

Radiographic evidence of mandibular osteoporosis improvement in Wistar rats treated with Ginkgo biloba

Abstract

Objective: Evaluate the effects of the extract of Ginkgo biloba (EGb) on the rat mandibular glucocorticoid-induced-osteoporosis. Method: 36 female rats were divided into six groups (n=6): control, osteoporosis, positive control and EGb1 (14mg/kg/day), EGb2 (28mg/kg/day), and EGb3 (56mg/kg/day) treatment. Treatments were conducted for 30 days after osteoporosis induction. The animals were euthanized and their left mandibles were removed and radiographed to evaluate the cortical and the periodontal bone support. The control group was compared with the osteoporosis group (Student’s t-test). The other groups were analyzed by ANOVA test followed by Tukey post-hoc test (p < 0.05). Results: There was a significant reduction in periodontal bone support in the osteoporosis group. The positive control group showed a significant increase in the mesial periodontal bone support, as well as the EGb group treated with 28 and 56 mg/Kg, which showed a significant increase in the mesial and distal periodontal bone support. The mandibular cortical was not affected by osteoporosis; however, the group treated with EGb using 56 mg/Kg showed a significant increase in the thickness of the mandibular cortical. Conclusions: The EGb recovered the periodontal bone support and increased the mandibular cortical thickness. The EGb may be effective in the treatment of osteoporosis. Copyright © 2009 John Wiley & Sons, Ltd. Source: http://onlinelibrary.wiley.com/doi/10.1002/ptr.2924/abstract


 

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