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Circulating isoflavone levels in CD‐1 mice: effect of oral versus subcutaneous delivery and frequency of administration
Author(s) -
Kaludjerovic Jovana,
Franke Adrian A.,
Ward Wendy E.
Publication year - 2011
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.25.1_supplement.234.5
Subject(s) - equol , genistein , daidzein , dosing , oral administration , corn oil , medicine , subcutaneous injection , isoflavones , soy isoflavones , pharmacology , endocrinology , chemistry
The CD‐1 mouse is often used to study biological effects of early life exposure to soy isoflavones (ISO) in infants. Most studies using CD‐1 mice have administered ISO by daily subcutaneous (s.c.) injection while infants receive oral feeds every few hours. The study objectives were to compare the serum levels of genistein (GEN), daidzein (DAI), equol and O‐DMA after s.c. injection and oral dosing; and to determine if frequency of oral administration results in different circulating levels of ISO and their metabolites. From postnatal day (PND) 1 to 5, pups (n=8–12) randomly received corn oil or ISO (total daily dose = 0.005 mg DAI + 0.010 mg GEN) by s.c. injection once a day, orally once a day or orally every 4 hours. On PND 5, an hour post‐treatment, mice were sacrificed. Serum was analyzed for GEN, DAI, equol and O‐DMA by LCMS. ISO groups had higher (p<0.05) serum GEN (1895–3391 ng/ml) and DAI (850–1580 ng/ml) concentrations vs. controls, regardless of route or frequency of administration and were similar among the dosing strategies. Serum concentrations of GEN and DAI were higher (p<0.05) among females (GEN: 2714 ± 393 ng/mL and DAI: 1205 ± 164 ng/ml) than males (GEN: 521 ± 439 ng/mL and DAI: 288 ± 184 ng/ml) across treatment groups. Serum equol and O‐DMA concentrations were negligible across groups. In conclusion, different routes of delivery and frequency of administration resulted in similar serum levels of GEN, DAI, equol or O‐DMA. Grant Funding Source : Canadian Institutes of Health Research to W.E.W. (funding reference number 89941) and a Frederick Banting and Charles Best Canada Graduate Scholarship Doctoral Award to J.K.