Reversal of Osteopenia in Ovariectomized Rats by Pentoxifylline: Evidence of Osteogenic and Osteo-Angiogenic Roles of the Drug
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Pentoxifylline (PTX) is a non-selective phosphodiesterase inhibitor and is used for the management of intermittent claudication. We tested whether PTX has oral efficacy in stimulating new bone formation. Rat calvarial osteoblasts (RCO) were used to study the effect of PTX on osteoblast differentiation and angiogenesis. Pharmacokinetic and pharmacodynamic studies were carried out in rats to determine an oral dose of PTX. In ovariectomized (OVX) rats with osteopenia, the effect of PTX on various skeletal parameters was studied, and compared with teriparatide. Effect of PTX on angiogenic signaling was studied by immunoblotting and relevant pharmacologic inhibitors. Bone vascularity was measured by intravenous injection of polystyrene fluorospheres followed by in vivo imaging, and angiogenesis was studied in vitro by tubulogenesis of endothelial cells and in vivo by Matrigel plug assay. Effective concentration (EC50) of PTX in RCO was 8.2 nM and plasma PTX level was 7 nM/mL after single oral dosing of 25 mg/kg, which was 1/6th the clinically used dose. At this dose, PTX enhanced bone regeneration at femur osteotomy site and completely restored bone mass, microarchitecture, and strength in OVX rats. Furthermore, PTX increased surface referent bone formation parameters and serum bone formation marker (PINP) without affecting the resorption marker (CTX-1). PTX increased the expression of vascular endothelial growth factor and its receptor in bones and osteoblasts. PTX also increased skeletal vascularity, tubulogenesis of endothelial cells and in vivo angiogenesis. Taken together, our study suggested that PTX at 16% of adult human oral dose completely reversed osteopenia in OVX rats by osteogenic and osteo-angiogenic mechanisms.
KeywordsPharmacokinetics Bone turnover Bone formation Osteopenia Vascularity Angiogenesis
The authors are thankful for the technical assistance provided by Dr. Kavita Singh at the confocal facility of the Electron Microscopy Unit, Sophisticated Analytical Instrument Facility (SAIF), and Mr. Navodayam Kalleti, Division of Toxicology for assistance with In-Vivo Imaging System.
Council of Scientific and Industrial Research, Government of India to Naibedya Chattopadhyay.
Compliance with Ethical Standards
Conflict of interest
Subhashis Pal, Konica Porwal, Himalaya Singh, Mohd Yaseen Malik, Mamunur Rashid, Chirag Kulkarni, Yasir Khan, Kumaravelu Jagavelu, Muhammad Wahajuddin, and Naibedya Chattopadhyay declare that they have no conflict of Interest.
Human and Animal Rights and Informed Consent
All animal experimental procedures were prior approved (Institutional Animal Ethics Committee approval no. CDRI/IAEC/2015/131) and conducted as per the guidelines laid by the Committee for the Purpose of Control and Supervision of Experiments on Animals. This article does not contain any studies with human participants performed by any of the authors. Informed consent is not required.
- 1.Salhiyyah K, Forster R, Senanayake E, Abdel-Hadi M, Booth A, Michaels JA (2015) Pentoxifylline for intermittent claudication. Cochrane Database Syst Rev 9:CD005262Google Scholar
- 4.Dauber IM, Lesnefsky EJ, Ashmore RC, Martel DM, Sheridan FM, Weil JV, Horwitz LD (1992) Coronary vascular injury due to ischemia-reperfusion is reduced by pentoxifylline. J Pharmacol Exp Ther 260:1250–1256Google Scholar
- 6.Cakmak G, Sahin MS, OzdemIr BH, KaradenIz E (2015) Effect of pentoxifylline on healing of segmental bone defects and angiogenesis. Acta Orthop Traumatol Turc 49:676–682Google Scholar
- 7.Yao W, Tian XY, Chen J, Setterberg RB, Lundy MW, Chmielzwski P, Froman CA, Jee WS (2007) Rolipram, a phosphodiesterase 4 inhibitor, prevented cancellous and cortical bone loss by inhibiting endosteal bone resorption and maintaining the elevated periosteal bone formation in adult ovariectomized rats. J Musculoskelet Neuronal Interact 7:119–130Google Scholar
- 21.China SP, Pal S, Chattopadhyay S, Porwal K, Kushwaha S, Bhattacharyya S, Mittal M, Gurjar AA, Barbhuyan T, Singh AK, Trivedi AK, Gayen JR, Sanyal S, Chattopadhyay N (2017) Globular adiponectin reverses osteo-sarcopenia and altered body composition in ovariectomized rats. Bone 105:75–86CrossRefGoogle Scholar
- 22.Pal S, Khan K, China SP, Mittal M, Porwal K, Shrivastava R, Taneja I, Hossain Z, Mandalapu D, Gayen JR, Wahajuddin M, Sharma VL, Trivedi AK, Sanyal S, Bhadauria S, Godbole MM, Gupta SK, Chattopadhyay N (2016) Theophylline, a methylxanthine drug induces osteopenia and alters calciotropic hormones, and prophylactic vitamin D treatment protects against these changes in rats. Toxicol Appl Pharmacol 295:12–25CrossRefGoogle Scholar
- 25.Sharan K, Mishra JS, Swarnkar G, Siddiqui JA, Khan K, Kumari R, Rawat P, Maurya R, Sanyal S, Chattopadhyay N (2011) A novel quercetin analogue from a medicinal plant promotes peak bone mass achievement and bone healing after injury and exerts an anabolic effect on osteoporotic bone: the role of aryl hydrocarbon receptor as a mediator of osteogenic action. J Bone Miner Res 26:2096–2111CrossRefGoogle Scholar
- 27.Dempster DW, Compston JE, Drezner MK, Glorieux FH, Kanis JA, Malluche H, Meunier PJ, Ott SM, Recker RR, Parfitt AM (2013) Standardized nomenclature, symbols, and units for bone histomorphometry: a 2012 update of the report of the ASBMR Histomorphometry Nomenclature Committee. J Bone Miner Res 28:2–17CrossRefGoogle Scholar
- 32.Athanasopoulos AN, Schneider D, Keiper T, Alt V, Pendurthi UR, Liegibel UM, Sommer U, Nawroth PP, Kasperk C, Chavakis T (2007) Vascular endothelial growth factor (VEGF)-induced up-regulation of CCN1 in osteoblasts mediates proangiogenic activities in endothelial cells and promotes fracture healing. J Biol Chem 282:26746–26753CrossRefGoogle Scholar
- 37.Cosman F, Gilchrist N, McClung M, Foldes J, de Villiers T, Santora A, Leung A, Samanta S, Heyden N, McGinnis JP 2nd, Rosenberg E, Denker AE (2016) A phase 2 study of MK-5442, a calcium-sensing receptor antagonist, in postmenopausal women with osteoporosis after long-term use of oral bisphosphonates. Osteoporos Int 27:377–386CrossRefGoogle Scholar
- 38.Pal S, Porwal K, Khanna K, Gautam MK, Malik MY, Rashid M, Macleod RJ, Wahajuddin M, Parameswaran V, Bellare JR, Chattopadhyay N (2019) Oral dosing of pentoxifylline, a pan-phosphodiesterase inhibitor restores bone mass and quality in osteopenic rabbits by an osteogenic mechanism: a comparative study with human parathyroid hormone. Bone 123:28–38CrossRefGoogle Scholar
- 45.Burkhardt R, Kettner G, Bohm W, Schmidmeier M, Schlag R, Frisch B, Mallmann B, Eisenmenger W, Gilg T (1987) Changes in trabecular bone, hematopoiesis and bone marrow vessels in aplastic anemia, primary osteoporosis, and old age: a comparative histomorphometric study. Bone 8:157–164CrossRefGoogle Scholar
- 47.Okano K, Wu S, Huang X, Pirola CJ, Juppner H, Abou-Samra AB, Segre GV, Iwasaki K, Fagin JA, Clemens TL (1994) Parathyroid hormone (PTH)/PTH-related protein (PTHrP) receptor and its messenger ribonucleic acid in rat aortic vascular smooth muscle cells and UMR osteoblast-like cells: cell-specific regulation by angiotensin-II and PTHrP. Endocrinology 135:1093–1099CrossRefGoogle Scholar
- 49.Prisby R, Guignandon A, Vanden-Bossche A, Mac-Way F, Linossier MT, Thomas M, Laroche N, Malaval L, Langer M, Peter ZA, Peyrin F, Vico L, Lafage-Proust MH (2011) Intermittent PTH(1-84) is osteoanabolic but not osteoangiogenic and relocates bone marrow blood vessels closer to bone-forming sites. J Bone Miner Res 26:2583–2596CrossRefGoogle Scholar
- 50.Pufe T, Claassen H, Scholz-Ahrens KE, Varoga D, Drescher W, Franke AT, Wruck C, Petersen W, Cellarius C, Schrezenmeir J, Gluer CC (2007) Influence of estradiol on vascular endothelial growth factor expression in bone: a study in Gottingen miniature pigs and human osteoblasts. Calcif Tissue Int 80:184–191CrossRefGoogle Scholar
- 54.Hock JM (2001) Anabolic actions of PTH in the skeletons of animals. J Musculoskelet Neuronal Interact 2:33–47Google Scholar