Nisaudah Radenahmad, Piyakorn Boonyoung, Krongkarn Kamkaew, Kanyaphak Chanchula, and Pornpimol Kirirat

pp. 599 - 606

Abstract

Apart from calcium itself, there are many factors including vitamin D and estrogen, that play important roles in bone
formation. Hormones, especially estrogen, used for replacement therapy is highly effective at reducing the rate of bone loss
and can also replace lost bone in postmenopausal women. Estrogen replacement therapy has been proposed to prevent
bone loss in males as well as in females. Estrogen, however, has been considered to be one of the hormonal risk factors of
benign prostatic hyperplasia and prostate cancer and also other side effects. With this background, in the present study,
young coconut juice (YCJ), that is known to contain the phytoestrogen, β-sitosterol, was investigated for its possible
beneficial effects on delaying osteoporosis using a male orchidectomized rat model, and as a replacement for estrogen
replacement therapy. In the present study we used the Grimelius stain which is a broad endocrine cell marker, especially in
the gastrointestinal (GI) tract to quantify the argyrophil endocrine cells and if possible to relate this to reflex GI functions,
e.g. calcium absorption, GI motility etc. that might have an influence on osteoporosis. There were five groups of rats (6 per
group) included in this study. The first group consisted of sham-operated rats, the second group consisted of orchidectomized (orx) rats, and the third group consisted of orx rats injected intraperitoneally with exogenous estrogen (2.5 μg/kgBW
of estradiol benzoate, EB) five days a week for two weeks. The fourth group consisted of orx rats that received YCJ (100 mL/
kgBW/day) and the fifth group was sham-operated rats receiving YCJ (100 mL/kgBW/day) for two weeks. After sacrifice,
the GI tract including stomach, small and large intestines were removed, fixed and paraffin embedded for routine H&E and
Grimelius silver staining. Most of the argyrophil cells were dispersed in the mucosa, particularly in the basal mucosa and
were generally round or spindle shaped and occasionally spherical. There was a regional distribution of the argyrophil
endocrine cells in all regions of the GI tract: stomach, duodenum, jejunum, ileum and colon, and that of the orx group had the
lowest numbers. Estradiol benzoate (EB) injection and YCJ feeding in the orx group reversed this phenomenon in all regions
of GI tract except for the colon. The sham+YCJ group had the highest number of argyrophil cells. Regression correlation
analysis between the argyrophil cell numbers and serum estrogen and testosterone levels were R2 0.0054 and 0.0355, respectively. The changes in the density of the GI argyrophil cells in the orchidectomized rats in the present study may contribute
to the GI function abnormality e.g. GI motility, GI calcium absorption, GI hormone production and secretion etc. frequently
encountered in patients with andropausal or elderly osteoporosis. Such impairment of calcium and probably other minerals in
the orx rats could be reversed by exogenous estrogen e.g estradiol benzoate (EB) supplement or by phytoestrogen e.g. YCJ
feeding as preliminarily detected by the numbers of argyrophil endocrine cells in this study.