of twohopsextractsontheuterus of ovariectomizedrats

ZANARDI MV; GUENTHER T; VOLLMER G; VARAYOUD J; DURANDO M; ZIERAU O

Congreso; Reunión Anual de Sociedades de Biociencias; 2020

A botanical dietary supplement from Humulus lupulus (hops) containsmainly xantohumol (XN) but also 8-prenylnaringenin (8-PN),among others. These hops extracts exhibit chemopreventive, cytotoxicand anti-inflammatory properties while 8-PN is a potent phytoestrogen.Although the 8-PN concentration in hops is very low, XN(the most abundant compound) can be metabolized to 8-PN. Herewe evaluated the potential estrogenic effects of hops and knockouthops (KO-hops) (reduced in XN and consequently in 8-PN) usingthe uterotrophic assay.Female Wistar rats (7 weeks old) were bilaterally ovariectomized(Ovx). Fourteen days after the surgery, rats were treated for threeconsecutive days with 17β-estradiol (E2: 4 μg/kg bw/day) or fed withthe vehicle (Ovx), hops or KO-hops at 8, 40 and 200 mg/kg bw/day. Animals were sacrificed 24 h after the last treatment. The uteruswas removed, weighed and processed for histology and mRNAextraction. We determine the relative uterine weight (rUW), luminalepithelial cell height (LECH) and the mRNA expression of the estrogenreceptor α (Esr1) and complement C3 (C3).The rUW and LECH were increased by E2 respect to Ovx (p<0.05).The rUW was similar between hops, KO-hops and Ovx groups. Anincrease in LECH was shown in hops 40 compared to Ovx (p<0.05).The mRNA expression of Esr1 and C3 was downregulated andupregulated, respectively by E2 treatment (p<0.05). Esr1 and C3mRNA were changed neither by hops nor by KO-hops respect tothe Ovx.In general, no estrogenic uterine effects were observed in responseto hops extracts, independently of their composition (hops and KOhops,not showed estrogenic response). In conclusion, the absenceof uterine estrogenic effects provides evidence for the safety ofboth extracts. Although this result encourage us to study the hopsextracts for its chemopreventive properties, more experiments areneeded to deeply characterize hops and their compounds.