ผลของน้ำมะพร้าวอ่อนต่อการป้องกันภาวะกระดูกพรุนในหนูขาวเพศผู้ที่ถูกตัดอัณฑะ

Abstract

From our previous study, the 100 ml/kgBW/day of young coconut juice (YCJ) is able to prevent bone loss by increasing the mandibular cancellous bone in orchidectomized (orx) rats. However, the large dose of YCJ at 100 ml/kgBW/day had side effects e.g. the great deposition of glycogen in liver. The purpose of this study was to determine the effects of YCJ on preventing osteoporosis in orchidectomized rats including the appropriate dose of YCJ for possible application. Male 8-month-old Wistar rats were randomly divided into 7 groups (n=70): Baseline, sham, orchidectomized (orx) rat, orx receiving estradiol benzoate 2.5 μg/kgBW/day, and orx receiving YCJ at dose of 10, 20 and 40 ml/kgBW/day. Eleven weeks after surgery, the rats were sacrificed, and their serum estradiol and testosterone levels were measured by chemiluminescence immunoassay (CIA) technique. The femur and the 5th lumbar vertebrae (L5) were collected for their micro-architectural studies using Micro-Computed tomography scan (Micro-CT scan). The histological sections of bones were prepared for % bone volume measurement. The immunohistochemistry for determining level of expression of estrogen receptors (ERC and ERB) on osteoblast and osteocyte was also performed. The micro-CT scans of the femur revealed that the Conn.D of the orx group was significantly less than the baseline group, while the orx groups receiving YCJ were not significantly different from either the sham or baseline group, the BV/TV of the orx groups receiving YCJ were significantly less than the sham group but were not different from the orx group. The bone parameters e.g. Tb.N, Tb.Th were not significantly different from the orx and sham group. In the L5, all bone parameters were not significantly different from the control groups. The % bone volume of YCJ treatment were also not significantly different among the groups. Immunohistochemistry of estrogen receptors also showed that the femur of the orx groups receiving YCJ significantly has more numbers of osteoblast expressing ERC than the orx group, while that of the numbers of osteoblast expressing ERB and osteocyte expressing both ERO and ERB were not significantly different from the orx and sham groups. In the L5, the numbers of osteoblast expressing ERⱭ of the orx groups receiving YCJ were not significantly different from the orx group but was significantly less than the sham group, while the numbers of osteoblast that express ERB and osteocyte that express ERO and ERB were not significantly different among the groups. In conclusion, the present study demonstrated that the YCJ at dose 10 ml/kgBW/day was the best dose to help preventing osteoporosis. It was possible that this effect was due to the phytoestrogen components of the YCJ which probably worked through the ERⱭ of osteoblast of femur to maintain bone mass. Furthermore, the parameters for evaluating liver, kidney, prostate gland, adrenal gland and seminal vesicle of the orx rats receiving YCJ were not different from the orx and sham groups, indicating that the doses of YCJ in this study were not harmful for liver and renal function.