The effect of the Ginkgo biloba extract in the expression of Bax, Bcl-2 and bone mineral content of Wistar rats with glucocorticoid-induced osteoporosis.
OBJECTIVE
Evaluate the effects of the extract of Ginkgo biloba (EGb) in the glucocorticoid-induced-osteoporosis through the Bax and Bcl-2 expressions by osteoblast cells, the x-ray and bone density of the tibia.


METHODS
Rats were divided into five groups: osteoporosis; EGb1 (28 mg/kg); EGb2 (56 mg/kg); alendronate (0.2 mg/animal) and control. The treatments were conducted for 20 (n = 30) and 30 days (n = 30). The Bax and Bcl-2 expressions were evaluated in osteoblasts of the mandibular alveolar bone. The tibias were radiographed to evaluate the X-ray and bone density. The control group was compared with the osteoporosis' (Student's t-test/Mann-Whitney). The other groups were analyzed by analysis of variance test followed by Dunnett/Dunnett T3 (p < 0.05).


RESULTS
When compared the osteoporosis to the control group (p <0.05): Bax and x-ray density increased; Bcl-2 and the bone density reduced. When compared with the osteoporosis group (p < 0.05), alendronate (30 days), EGb1 and EGb2 (20/30 days) increased the Bcl-2 expression; EGb2 and alendronate (20 days) EGb1 and EGb2 (30 days) reduced the Bax expression; and EGb1 and EGb2 (20/30 days) reduced the X-ray density.


CONCLUSIONS
The EGb improved the Bcl-2 and reduced the Bax expression by osteoblasts in the mandibular alveolar bone and recovered the mineral content in the tibia of rats with glucocorticoid-induced-osteoporosis.
Centro de Biologia da Reprodução-Federal University of Juiz de Fora, Juiz de Fora, MG, Brazil. ledamarilia@yahoo.com.br
Leda Marília Fonseca
LM
Lucinda
Beatriz Julião Vieira
BJ
Aarestrup
Vera Maria
VM
Peters
João Evangelista de Paula
JE
Reis
Roberto Sotto Maior Fortes de
RS
Oliveira
Martha de Oliveira
Mde O
Guerra
D000818:Animals; D015519:Bone Density / Q000187:drug effects*; D005260:Female; D020441:Ginkgo biloba / Q000737:chemistry*; D005938:Glucocorticoids / Q000009:adverse effects; D008334:Mandible / Q000187:drug effects; D010006:Osteoblasts / Q000187:drug effects; D010024:Osteoporosis / Q000139:chemically induced / Q000188:drug therapy*; D010936:Plant Extracts / Q000494:pharmacology*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism*; D011859:Radiography; D051381:Rats; D017208:Rats, Wistar; D013977:Tibia / Q000000981:diagnostic imaging / Q000187:drug effects; D051028:bcl-2-Associated X Protein / Q000378:metabolism*
C494828:Bax protein, rat; D005938:Glucocorticoids; D010936:Plant Extracts; D019253:Proto-Oncogene Proteins c-bcl-2; D051028:bcl-2-Associated X Protein