The soybean concentrated extract proliferates the vagina of adult rats.
OBJECTIVE
The aim of this study was to evaluate changes induced on the vagina of ovariectomized rats after treatment with soybean concentrated extract or conjugated equine estrogens and the association of both drugs.


METHODS
We conducted an experimental study with 50 ovariectomized rats that were randomly divided into five equal groups of 10 animals: GI received vehicle, GII received soybean concentrated extract 46 mg/kg per day, GIII received soybean concentrated extract 120 mg/kg per day, GIV received conjugated equine estrogens 50 μg/kg per day, and GV received conjugated equine estrogens 50 μg/kg and soybean concentrated extract 46 mg/kg per day. The substances were administered by gavage during 21 consecutive days. After that, the animals were killed under anesthesia and the vagina was removed for histological and immunohistochemical analysis. Data were initially submitted to analysis of variance. Whenever a significant difference was detected, the study was complemented with the Tukey-Kramer test for multiple comparisons.


RESULTS
GII did not show any differences on the vaginal epithelium or collagen compared with GI. GIII presented an increase in vaginal epithelium and collagen amount. GIV had the highest amount of collagen and the signals of vaginal proliferation. GV did not show any additional effect compared with GIV.


CONCLUSIONS
Our data suggest that a high dose of isoflavone-rich soy extract may have positive effects on the vaginal structures of ovariectomized rats, but this action is less than that of estrogen treatment on vaginal thickness. In addition, soy extract may not block the estrogen effect on vaginal tissue.
Carbonel
Adriana Aparecida Ferraz
AA
Department of Morphology and Genetics, Federal University of São Paulo, Brazil.
Baracat
Maria Cândida Pinheiro
MC
Simões
Ricardo Santos
RS
Simões
Manuel Jesus
MJ
Baracat
Edmund Chada
EC
Soares
José Maria
JM
D000704:Analysis of Variance; D000818:Animals; D005260:Female; D007529:Isoflavones / Q000494:pharmacology*; D019394:Ki-67 Antigen / Q000378:metabolism; D010052:Ovariectomy; D010936:Plant Extracts / Q000494:pharmacology*; D018809:Proliferating Cell Nuclear Antigen / Q000378:metabolism; D011446:Prospective Studies; D011897:Random Allocation; D051381:Rats; D016037:Single-Blind Method; D013025:Glycine max; D014621:Vagina / Q000033:anatomy & histology* / Q000187:drug effects* / Q000378:metabolism; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism
D007529:Isoflavones; D019394:Ki-67 Antigen; D010936:Plant Extracts; D018809:Proliferating Cell Nuclear Antigen; D042461:Vascular Endothelial Growth Factor A