Methods: Pseudopregnancy (pc) was induced in cyclic Sprague-Dawley rats by sterile mating. Subcutaneous injection of nicotine tartrate (7.5 mg/kg/day) was scheduled from day 1 through day 5, day 5 through day 9 or day 1 through day 9 of pc. In another group of pseudopregnant rats, concomitant treatment of nicotine tartrate concurrently with progesterone (2 mg/day) was scheduled from day 1 through day 9 pc. Control groups received subcutaneous injections of vehicle only. Endometrial decidualization was induced on day 5 pc. On day 10 pc, animals were sacrificed.The degree of decidual growth and circulating levels of estrogen and progesterone were measured.
Results: The decidual growth in all the first three nicotine-treated groups of animals was significantly reduced, particularly in the animals treated with nicotine from day 1 through day 9 pc. Plasma estrogen levels were significantly elevated in animals treated with nicotine from day 1 through day 9 pc. Conversely, levels of plasma progesterone were found to be significantly attenuated in the same group of nicotine-treated animals compared to controls. Exogenous replacement of progesterone, however, caused a higher degree of endometrial decidualization compared to the nicotine-treated group but it was slightly less than when compared to control.
Conclusions: In conclusion, nicotine-induced progesterone deficiency with a corresponding elevation of estrogen may possibly attenuate the degree of endometrial decidualization in pseudopregnant rats.
AIMS OF STUDY: To demonstrate Marantodes pumilum leaves aqueous extract (MPE) has an effect on uterine contraction after delivery and to elucidate the molecular mechanisms involved.
METHODS: Day-1 post-delivery female rats were given MPE (100, 250 and 500 mg/kg/day) orally for seven consecutive days. A day after the last treatment (day-8), rats were sacrificed and uteri were harvested and subjected for ex-vivo contraction study using organ bath followed by protein expression and distribution study by Western blotting and immunohistochemistry techniques, respectively. The proteins of interest include calmodulin-CaM, myosin light chain kinase-MLCK, sarcoplasmic reticulum Ca2+-ATPase (SERCA), G-protein α and β (Gα and Gβ), inositol-triphosphate 3-kinase (IP3K), oxytocin receptor-OTR, prostaglandin (PGF)2α receptor-PGFR, muscarinic receptor-MAChR and estrogen receptor (ER) isoforms α and β. Levels of estradiol and progesterone in serum were determined by enzyme-linked immunoassay (ELISA).
RESULTS: Ex-vivo contraction study revealed the force of uterine contraction increased with increasing doses of MPE. In addition, expression of CaM, MLCK, SERCA, Gα, Gβ, IP3K, OTR, PGF2α, MAChR, Erα and ERβ in the uterus increased with increasing doses of MPE. Serum analysis indicate that estradiol levels decreased while progesterone levels remained low at day-8 post-partum in rats receiving 250 and 500 mg/kg/day MPE.
CONCLUSIONS: These findings support the claims that MPE help to firm the uterus and pave the way for its use as a uterotonic agent after delivery.
MAIN METHODS: Cell mineralization capacity of phytoestrogens was investigated by evaluating calcium, phosphate content and alkaline phosphatase activity. Bone related markers, osteocalcin and osteonectin, responsible in maintaining mineralization were also measured.
KEY FINDINGS: BPA is significantly interfering with bone mineralization in hFOB 1.19 cells. However, the enhanced mineralization efficacy of daidzein and genistein (particularly at a dose of 5 and 40 μg/mL, respectively) was evidenced by increasing calcium and phosphate content, higher ALP activity, compared to the untreated BPA group. The quantitative analyses were confirmed through morphological findings. Osteocalcin and osteonectin levels were increased in phytoestrogens-treated cells. These findings revealed the potential effect of phytoestrogens in reverting the demineralization process due to BPA exposure in hFOB 1.19 cells.
SIGNIFICANCE: We found that osteoblast differentiation and mineralization were maintained following treatment with phytoestrogens under BPA exposure.