Planta Med 2010; 76(3): 235-240
DOI: 10.1055/s-0029-1186136
Pharmacology
Original Papers
© Georg Thieme Verlag KG Stuttgart · New York

Changes in the Histomorphometric and Biomechanical Properties of the Proximal Femur of Ovariectomized Rat after Treatment with the Phytoestrogens Genistein and Equol

Mohammad Tezval1 , Stephan Sehmisch1 , Dana Seidlová-Wuttke2 , Thomas Rack1 , Leila Kolios1 , Wolfgang Wuttke2 , Klaus Michael Stuermer1 , Ewa Klara Stuermer1
  • 1Department of Trauma Surgery, Plastic and Reconstructive Surgery, Georg-August-University of Goettingen, Goettingen, Germany
  • 2Department of Clinical and Experimental Endocrinology, Georg-August-University of Goettingen, Goettingen, Germany
Further Information

Publication History

received June 9, 2009 revised July 27, 2009

accepted August 15, 2009

Publication Date:
17 September 2009 (online)

Abstract

The isoflavonoids found in soy have attracted great interest as dietary phytoestrogens that might be effective for postmenopausal hormone replacement therapy. Special attention has been devoted to the hormonal effects of various isoflavonoids, like genistein (GEN) and daidzein's (DAID) potent metabolite, equol (EQ). Here we aimed to investigate the short-term effects of genistein and equol on the proximal femur of ovariectomized (OVX) rats. Forty-eight, 3-month-old female Sprague-Dawley rats were ovarectomized; after eight weeks the bilateral osteotomy and osteosynthesis (OS) of their tibiae was performed and the rats were randomly divided into the following four groups: OVX control group (C), treated with estradiol-17beta (E2) ‐benzoate (E; daily intake 0.086 mg/d per animal), genistein (GEN; daily intake 12.7 mg/d per animal) and equol (EQ; daily intake 4.65 mg/d per animal). At 5 weeks postoperatively (OS), the breaking test was performed on the trochanteric region of femur. Additionally, histomorphometric assessment, and trabecular and cortical bone microstructure analyses were performed. The relative gain of body weight (BW) in the EQ (24 %) group was significantly (p < 0.05) lower than in the C (33 %) and GEN (30 %) groups. After treatment for 5 weeks, the maximal load (Fmax) and yield load (yL) were higher (p < 0.05 for the weight-adapted results) in the E (188.4 N resp. 113.1 N) and EQ (177.3 N resp. 112 N) groups as compared to C (162.8 N resp. 109.1 N) and GEN (165.7 N resp. 108.8 N). In the histomorphometric tests the E- (trabecular area (Tb.Ar) = 74.93 %, trabecular nodes/mm2 (N.Nd/mm2) = 48.65) and EQ-treated (Tb.Ar = 63.13 %, N.Nd/mm2 = 43.72) animals showed significant improvement with regard to Tb.Ar and trabecular connectivity (N.Nd./mm2) in comparison to C (Tb.Ar = 46.84, N.Nd/mm2 = 31.86) and GEN (Tb.Ar = 48.22 %, N.Nd/mm2 = 34.15). There were no differences in relative cortical width (Ct.Wi) among the four groups. The treatment with EQ resulted in improved biomechanical and histomorphometric properties as compared to the treatment with GEN. Thus, of the studied substances, EQ seems to be a possible alternative to hormone replacement therapy, but further studies are needed.

References

  • 1 Lin J H, Chen I W, Duggan D E. Effects of dose, sex, and age on the disposition of alendronate, a potent antiosteolytic bisphosphonate, in rats.  Drug Metab Dispos. 1992;  20 473-478
  • 2 Burger H. Hormone replacement therapy in the post-Women's Health Initiative era. Report a meeting held in Funchal, Madeira, February 24–25, 2003.  Climacteric. 2003;  6 (Suppl. 1) 11-36
  • 3 Wuttke W, Jarry H, Westphalen S, Christoffel V, Seidlova-Wuttke D. Phytoestrogens for hormone replacement therapy?.  J Steroid Biochem Mol Biol. 2002;  83 133-147
  • 4 Kessel B. Alternatives to estrogen for menopausal women.  Proc Soc Exp Biol Med. 1998;  217 38-44
  • 5 Picherit C, Coxam V, Bennetau-Pelissero C, Kati-Coulibaly S, Davicco M J, Lebecque P, Barlet J P. Daidzein is more efficient than genistein in preventing ovariectomy-induced bone loss in rats.  J Nutr. 2000;  130 1675-1681
  • 6 Kelly G E, Joannou G E, Reeder A Y, Nelson C, Waring M A. The variable metabolic response to dietary isoflavones in humans.  Proc Soc Exp Biol Med. 1995;  208 40-43
  • 7 Cos P, De Bruyne T, Apers S, Vanden Berghe D, Pieters L, Vlietinick A J. Phytoestrogens: recent developments.  Planta Med. 2003;  69 589-599
  • 8 Morito K, Hirose T, Kinjo J, Hirakawa T, Okawa M, Nohara T, Ogawa S, Inoue S, Muramatsu M, Masamune Y. Interaction of phytoestrogens with estrogen receptors alpha and beta.  Biol Pharm Bull. 2001;  24 351-356
  • 9 Ishihara A, Sasaki T, Debari K, Furuya R, Kawawa T, Ramamurthy N S, Golub M L. Effects of ovariectomy on bone morphology in maxillae of mature rats.  J Electron Microscop (Tokyo). 1999;  48 465-469
  • 10 Leitner M M, Tami A E, Montavon P M, Ito K. Longitudinal as well as age-matched assessments of bone changes in the mature ovariectomized rat model.  Lab Anim. 2009;  43 266-271
  • 11 Mathey J, Mardon J, Fokialakis N, Puel C, Kati-Coulibaly S, Mitakou S, Bennetau-Pelissero C, Lamothe V, Davicco M, Lebecque P, Horcajada M N, Coxam V. Modulation of soy isoflavones bioavailability and subsequent effects on bone health in ovariectomized rats: the case for equol.  Osteoporos Int. 2007;  18 671-679
  • 12 Thompson D D, Simmons H A, Pirie C M, Ke H Z. FDA Guidelines and animal models for osteoporosis.  Bone. 1995;  17 125S-133S
  • 13 Wronski T J, Lowry P L, Walsh C C, Ignaszewski L A. Skeletal alterations in ovariectomized rats.  Calcif Tissue Int. 1985;  37 324-328
  • 14 Kolios L, Sehmisch S, Daub F, Rack T, Tezval M, Stuermer K M, Stuermer E K. Equol but not genistein improves early metaphyseal fracture healing in osteoporotic rats.  Planta Med. 2009;  75 459-465
  • 15 Stuermer E K, Seidlova-Wuttke D, Sehmisch S, Rack T, Wille J, Frosch K H, Wuttke W, Stuermer K M. Standardized bending and breaking test for the normal and osteoporotic metaphyseal tibias of the rat: effect of estradiol, testosterone, and raloxifene.  J Bone Miner Res. 2006;  21 89-96
  • 16 Wuttke W, Jarry H, Seidlova-Wuttke D. Isoflavones – safe food additives or dangerous drugs?.  Ageing Res Rev. 2007;  6 150-188
  • 17 Raimondi S, Roncaglia L, De Lucia M, Amaretti A, Leonardi A, Pagnoni U M, Rossi M. Bioconversion of soy isoflavones daidzin and daidzein by Bifidobacterium strains.  Appl Microbiol Biotechnol. 2009;  81 943-950
  • 18 Wang J, Shang F, Mei Q, Wang J, Zhang R, Wang S. NO-donating genistein prodrug alleviates bone loss in ovariectomised rats.  Swiss Med Wkly. 2008;  138 608-613
  • 19 Dai R, Ma Y, Sheng Z, Jin Y, Zhang Y, Fang L, Fan H, Liao E. Effects of genistein on vertebral trabecular bone microstructure, bone mineral density, microcracks, osteocyte density, and bone strength in ovariectomized rats.  J Bone Miner Metab. 2008;  26 342-349
  • 20 Sehmisch S, Hammer F, Christoffel J, Seidlova-Wuttke D, Tezval M, Wuttke W, Stuermer K M, Stuermer E K. Comparison of the phytohormones genistein, resveratrol and 8-prenylnaringenin as agents for preventing osteoporosis.  Planta Med. 2008;  74 794-801
  • 21 Kim H K, Nelson-Dooley C, Della-Fera M A, Yang J Y, Zhang W, Duan J, Hartzell D L, Hamrick M W, Baile C A. Genistein decreases food intake, body weight, and fat pad weight and causes adipose tissue apoptosis in ovariectomized female mice.  J Nutr. 2006;  136 409-414
  • 22 Rimoldi G, Christoffel J, Seidlova-Wuttke D, Jarry H, Wuttke W. Effects of chronic genistein treatment in mammary gland, uterus, and vagina.  Environ Health Perspect. 2007;  115 (Suppl. 1) 62-68
  • 23 Rachon D, Vortherms T, Seidlova-Wuttke D, Wuttke W. Effects of dietary equol on body weight gain, intra-abdominal fat accumulation, plasma lipids, and glucose tolerance in ovariectomized Sprague-Dawley rats.  Menopause. 2007;  14 925-932

Dr. Mohammad Tezval

Department of Trauma Surgery, Plastic and Reconstructive Surgery
Georg-August-University Hospital

Robert Koch Str. 40

37075 Goettingen

Germany

Phone: + 49 5 51 39 61 14

Fax: + 49 5 51 39 89 81

Email: mtezval@med.uni-goettingen.de