ORIGINAL PAPER Anti-osteoporotic effects of Pueraria candollei var. mirifica on bone mineral density and histomorphometry in estrogen-deficient rats Sarocha Suthon 1 • Sukanya Jaroenporn 1 • Narattaphol Charoenphandhu 2,3 • Panan Suntornsaratoon 2,3 • Suchinda Malaivijitnond 1 Received: 30 October 2015 / Accepted: 5 January 2016 Ó The Japanese Society of Pharmacognosy and Springer Japan 2016 Abstract Although it has been clearly shown that Pueraria mirifica and its phytoestrogens can mimic estrogen in pre- venting bone loss, as osteoporosis is an asymptomatic dis- ease, the therapeutic effects of P. mirifica should be acknowledged. In this study, 6-month-old female rats were ovariectomized, kept for 4 weeks to induce bone loss, divi- ded into five groups, and treated with P. mirifica at doses of 0, 5, 25, and 50 mg/kg BW/day (PM0, PM5, PM25, and PM50 groups, respectively) or 7 mg/kg BW/day of puerarin (PU group) for 12 weeks. Only the trabecular bone mineral densities (BMDs) of tibia metaphysis (at the 12th, 14th, and 16th week) and total and trabecular BMDs of L4 (at the 16th week) of the PM50 group were significantly higher than those of the PM0 group. However, the BMDs of tibia metaphysis and L4 at the 16th week of the study period were kept significantly lower than those of the 0 week, and the BMD was also significantly lower than that of the 4th week for tibia metaphysis. The trabecular bone area (BV/TV), trabecular number (Tb.N), and osteoblast surface (Ob.S/BS) were significantly higher, and trabecular space (Tb.Sp) was significantly lower in the PM50 group, as compared with those of the PM0 group. This study indicates that P. mirifica could be used as an anti-osteoporotic agent for post- menopausal women. Since P. mirifica could mainly retain bone mass at the levels before bone loss is initiated, the use of other anabolic agents in combination with P. mirifica is recommended for osteoporotic patients. Keywords Bone loss  Phytoestrogens  Osteoblast  Osteoclast Introduction Osteoporosis is a common disorder of aging, which is characterized by low bone mass and micro-architectural deterioration of bone tissue [1]. The cause of the disease is multifactorial with the dominant factor often sex hormone deficiency, particularly estrogen deficiency in post- menopausal women [1, 2]. Several studies have demon- strated the beneficial effect of estrogen replacement therapy in preventing and curing bone loss following menopause [3–6]. However, use of estrogens has several downsides that may lead to serious side effects such as breast or endometrial cancer [7]. Thus, other antiresorptive and anabolic agents have been widely prescribed. Oral bisphosphonates are currently the most potent antiresorptive agents for prevention or treat- ment of osteoporosis. They can reduce vertebral and hip fractures by 50–60 % in postmenopausal women. How- ever, bisphosphonates have adverse side effects on the gastrointestinal tract such as induction of esophageal ulceration, acid reflux, vomiting, and heart burn, which is why physicians hesitate to use these in some women [8]. Another weak point for antiresorptive agents is that they are unable to build a new bone or lead to bone formation; thus, it might not be justified to use them with osteoporotic S. Jaroenporn and S. Malaivijitnond contributed equally. & Suchinda Malaivijitnond suchinda.m@chula.ac.th 1 Department of Biology, Faculty of Science, Chulalongkorn University, 254 Phayathai Road, Bangkok 10330, Thailand 2 Center of Calcium and Bone Research (COCAB), Faculty of Science, Mahidol University, Bangkok 10400, Thailand 3 Department of Physiology, Faculty of Science, Mahidol University, Bangkok 10400, Thailand 123 J Nat Med DOI 10.1007/s11418-016-0965-5