8-prenylnaringenin and Osteoporosis--Postmenopausal

Hop (

Topics: Antineoplastic Agents, Phytogenic; Female; Flavanones; Humans; Humulus; Menopause; Molecular Structure; Osteoporosis, Postmenopausal; Phytoestrogens

Hop extract is a long used medicinal product and, regarding hormonal activities, in 1999 a number of prenylflavanones have been identified as its major constituents with 8-prenylnaringenin (8-PN) being the main active estrogenic compound. There have been several in vivo studies performed that demonstrate the potential of hop extract and the single compound 8-PN to alleviate climacteric symptoms like osteoporosis, vasomotoric complaints, and sexual motivation. On the other hand, only a few clinical studies have been performed so far, and these mainly focused on menopausal discomforts, especially hot flushes, yielding rather inconclusive results. Despite preferentially activating estrogen receptor α, 8-PN is only slightly uterotrophic, but it also elucidates estrogenic effects on the mammary gland. In conclusion, although hop extract and especially 8-PN are promising candidates as a relief for climacteric symptoms, data on the safety and efficacy is still scarce.

Topics: Estrogen Receptor alpha; Female; Flavanones; Hot Flashes; Humans; Humulus; Mammary Glands, Human; Menopause; Osteoporosis, Postmenopausal; Phytoestrogens; Phytotherapy; Plant Extracts; Sexual Dysfunctions, Psychological; Uterus

Estrogen deficiency increases the risk of osteoporosis and fracture. The aim of this study was to investigate whether a hop extract standardized in 8-prenylnaringenin (8-PN), a potent phytoestrogen, could improve bone status of osteopenic women and to explore the gut microbiome roles in this effect. In this double-blind, placebo-controlled, randomized trial, 100 postmenopausal, osteopenic women were supplemented with calcium and vitamin D3 (CaD) tablets and either a hop extract (HE) standardized in 8-PN (

Topics: Bone Density; Bone Diseases, Metabolic; Double-Blind Method; Female; Gastrointestinal Microbiome; Humans; Osteoporosis, Postmenopausal; Postmenopause; Quality of Life

Plant secondary metabolites with estrogenic activity (phyto-estrogens) have been studied in the past as a potential alternative to classical hormone-replacement therapy (HRT) in menopausal women. No final verdict on the efficacy of soy or red clover based pharmaceutical preparations has been reached despite numerous clinical studies. We have studied the novel and most potent phyto-estrogen 8-prenylnaringenin (8-PN) in adult ovariectomized rats, an established animal model to mimic hormone dependent osteoporosis in menopausal women. Our results demonstrate that 8-PN can completely protect from ovariectomy induced bone-loss while exhibiting minimal, (dose independent) trophic effects on uterus and endometrium. It is estimated that at equivalent bone protective doses of 17beta-estradiol and 8-PN, the phyto-estrogen has a 10-fold lower stimulatory effect on uterus and endometrium. The bone tissue specific effect of 8-PN was confirmed in a transgenic reporter mouse model (ERE-Luc mice). Here we also found pronounced estrogenic activity in prostate. Present results add important aspects to the pharmacological profile of 8-PN and position this compound as an interesting alternative new candidate for treatment of peri- and postmenopausal symptoms.

Topics: Animals; Body Weight; Bone Density; Epithelium; Estradiol; Female; Flavanones; Humans; Male; Mice; Mice, Transgenic; Osteoporosis, Postmenopausal; Ovariectomy; Phytoestrogens; Prostate; Rats; Rats, Sprague-Dawley; Uterus