ORX Group Research Articles

The Effect of Apple Juice on Antioxidant Enzymes and Lipid Profiles in Orchidectomized Rats

Background:: The age-dependent worsening of lipid profiles increased the risk of cardiovascular disease in males. Eating fruits and vegetables is known to be beneficial on lipid profile. Objectives:: The objective of this research was to delineate whether drinking daily squeezed apple juice (AJ) modulates lipid profile and antioxidant enzymes in the animal model that gonadectomized. Materials and Methods:: In this experimental study, 28 male rats were equally divided among the following 4 groups: group I (control), orchidectomized (ORX), ORX +AJ 10%, and ORX+ AJ 25%. After 60 days of drinking AJ, superoxide dismutase (SOD), alkaline phosphatase (ALP), cholesterol, LDL, HDL and triglycerides in serum were evaluated. Data analyzed by SPSS-16 and computed using one way ANOVA followed by Tukey multiple comparison test. P < 0.05 was statistically significant. Results:: In the ORX group compared with the sham group serum SOD and ALP activities decreased (P < 0.05), while serum cholesterol, triglycerides, LDL increased but HDL decreased in ORX groups (P < 0.05). In contrast to the ORX group, drinking AJ decreased (P < 0.05) concentration of LDL, TG and cholesterol in the serum. AJ also increased (P < 0.05) serum HDL, SOD and ALP activities compared with the ORX group. Conclusions:: Drinking AJ prevented oxidative stress by elevating serum antioxidant enzymes.

The Effect of Apple Juice on Antioxidant Enzymes and Lipid Profiles in Orchidectomized Rats

Materials and Methods: In this experimental study, 28 male rats were equally divided among the following 4 groups: group I (control), orchidectomized (ORX), ORX +AJ 10%, and ORX+ AJ 25%. After 60 days of drinking AJ, superoxide dismutase (SOD), alkaline phosphatase (ALP), cholesterol, LDL, HDL and triglycerides in serum were evaluated. Data analyzed by SPSS-16 and computed using one way ANOVA followed by Tukey multiple comparison test. P < 0.05 was statistically significant. Results: In the ORX group compared with the sham group serum SOD and ALP activities decreased (P < 0.05), while serum cholesterol, triglycerides, LDL increased but HDL decreased in ORX groups (P < 0.05). In contrast to the ORX group, drinking AJ decreased (P < 0.05) concentration of LDL, TG and cholesterol in the serum. AJ also increased (P < 0.05) serum HDL, SOD and ALP activities compared with the ORX group. Conclusions: Drinking AJ prevented oxidative stress by elevating serum antioxidant enzymes.

Orchidectomy-induced alterations in volumetric bone density, cortical porosity and strength of femur are attenuated by dietary conjugated linoleic acid in aged guinea pigs

Age-related osteoporosis and sarcopenia are ascribed in part to reductions in anabolic hormones. Dietary conjugated linoleic acid (CLA) improves lean and bone mass, but its impact during androgen deficiency is not known. This study tested if CLA would attenuate the effects of orchidectomy (ORX)-induced losses of bone and lean tissue. Male guinea pigs (n=40; 70–72 weeks), were randomized into four groups: 1) SHAM+Control diet, 2) SHAM+CLA diet, 3) ORX+Control diet, 4) ORX+CLA diet. Baseline blood sampling and dual-energy X-ray absorptiometry (DXA) scans were conducted, followed by surgery 4days later with the test diets started 7days after baseline sampling. Serial blood sampling and DXA scans were repeated 2, 4, 8 and 16weeks on the test diets. Body composition and areal BMD (aBMD) of whole body, lumbar spine, femur and tibia were measured using DXA. At week 16, muscle protein fractional synthesis rate (FSR), volumetric BMD (vBMD), microarchitecture and bone strength were assessed. Body weight declined after SHAM and ORX surgery, with slower recovery in the ORX group. Dietary CLA did not affect weight or lean mass, but attenuated gains in fat mass. Lean mass was stable in SHAM and reduced in ORX by 2weeks with whole body and femur bone mineral content (BMC) reduced by 4weeks; CLA did not alter BMC. By week 16 ORX groups had lower free testosterone and myofibrillar FSR, yet higher cortisol, osteocalcin and ionized calcium with no alterations due to CLA. ORX+Control had higher prostaglandin E2 (PGE2) and total alkaline phosphatase compared to SHAM+Control whereas ORX+CLA were not different from SHAM groups. Femur metaphyseal vBMD was reduced in ORX+CTRL with the reduction attenuated by CLA. Femur cortical thickness (Ct.Th.) and biomechanical strength were reduced and cortical porosity (Ct.Po.) elevated by ORX and attenuated by CLA. This androgen deficient model with a sarcopenic-osteoporotic phenotype similar to aging men responded to dietary CLA with significant benefits to femur density and strength.

Annatto tocotrienol improves indices of bone static histomorphometry in osteoporosis due to testosterone deficiency in rats.

This study aimed to evaluate the effects of annatto tocotrienol on indices of bone static histomorphometry in orchidectomized rats. Forty male rats were randomized into baseline (BL), sham (SH), orchidectomized (ORX), annatto tocotrienol-treated (AnTT) and testosterone enanthate-treated (TE) groups. The BL group was sacrificed upon receipt. All rats except the SH group underwent bilateral orchidectomy. Annatto tocotrienol at 60 mg/kg body weight was administered orally daily to the AnTT group for eight weeks. Testosterone enanthate at 7 mg/kg body weight was administered intramuscularly once weekly for eight weeks to the TE group. The rat femurs were collected for static histomorphometric analysis upon necropsy. The results indicated that the ORX group had significantly higher osteoclast surface and eroded surface, and significantly lower osteoblast surface, osteoid surface and osteoid volume compared to the SH group (p < 0.05). Annatto tocotrienol and testosterone enanthate intervention prevented all these changes (p < 0.05). The efficacy of annatto tocotrienol was on par with testosterone enanthate. In conclusion, annatto tocotrienol at 60 mg/kg can prevent the imbalance in bone remodeling caused by increased osteoclast and bone resorption, and decreased osteoblast and bone formation. This serves as a basis for the application of annatto tocotrienol in hypogonadal men as an antiosteoporotic agent.

The effects of orchidectomy and supraphysiological testosterone administration on trabecular bone structure and gene expression in rats

Objective: This study aimed to determine the effects of orchidectomy and supraphysiological testosterone replacement on trabecular structure and gene expression in the bone.Methods: Twenty-four 3-month old male rats were randomized into sham (SH), orchidectomized (ORX) and testosterone-treated (TE) groups. Orchidectomy was performed on the ORX and TE group. Weekly testosterone enanthate intramuscular injection at 7 mg/kg body weight was administered to the TE group for 8 weeks while the other groups received peanut oil as vehicle. Blood was collected before and after treatment for serum testosterone analysis. The femora and tibiae were harvested after the treatment period for trabecular structure and gene expression analysis.Results: The trabecular bone volume decreased significantly and the porosity increased significantly in the ORX group compared to the SH group (p < 0.05). Testosterone treatment prevented all these changes (p < 0.05). The expression of osteogenic genes decreased significantly in the ORX group compared to the SH group (p < 0.05). Testosterone treatment decreased the expressions of RANKL and OPG genes significantly (p < 0.05).Conclusion: Orchidectomy-induced degeneration in trabecular structure is caused by a decrease in the expressions of osteogenic genes. Supraphysiological testosterone replacement is able to prevent these degenerative changes in the bone despite the modest changes in gene expression.

Effects of genistein on stereological and hormonal characteristics of the pituitary somatotrophs in rats.

The hypothalamic-pituitary somatotropic system plays a pivotal role in the regulation of physiological processes and metabolism, which is modulated by gonadal steroids. Considering that genistein belongs to the phytoestrogen family and acts via similar mechanisms to estrogens, the present study was designed to demonstrate whether genistein modulates the morphofunctional characteristic of somatotrophs [growth hormone (GH) cells] in adult rats in comparison with the effects of estradiol. In the study, the orchidectomized adult rats were used as an appropriate model system for testing the effects of this hormone-like substance. Changes in the pituitary somatotrophs were evaluated histologically and stereologically, while GH level was determined biochemically. Using immunolabelling and stereological methods, we showed that orchidectomy (Orx) provoked the decrease of GH cell volume density. After estradiol treatment of Orx rats, the most prominent change concerned the pituitary relative intensity of GH fluorescence and circulating GH level, which were elevated 77 % and 4.7-fold, respectively. Clearly, in contrast to orchidectomy, estradiol treatment enhanced the GH cells activity. Genistein treatment increased pituitary weight and volume, GH cell volume density, the total number of GH cells, and GH blood concentration (1.3-fold) in comparison to the Orx group. Although identical tendencies followed estradiol and genistein administration, the changes observed after genistein treatment were milder compared to estradiol treatment.

Intratesticular injection of hypertonic saline : non-invasive alternative method for animal castration model.

Previous studies, including our own, have demonstrated that the intratesticular injection of hypertonic saline (20%) decreased serum testosterone level which was similar to the surgical castration in the rat, showing the state of chemical castration. In the present study, we further verify the efficacy of this less invasive method as an alternative of surgical orchidectomy in the andevrepological field. Sterilized 20% saline was directly injected into the adult male rats (750 μl per testis). The tested rats were divided into 3 groups including intact group (intact), orchidectomy group (ORX) and saline injection group (SAL) after bilateral orchidectomy was performed at the same day of injection. All rats were sacrificed at 4 weeks after injection. The reproductive organs (testes, epididymis, seminal vesicles and prostates) were collected and used for DNA and protein pattern analyses. Also, patho-histological studies on the testes were performed. In contrast to the intact group, similar DNA damages of testis and seminal vesicle were appeared in ORX group and SAL group. The DNA degradations seemed to be the results of necrosis rather than apoptosis. In the protein pattern analysis, all the testing tissues exerted similar patterns in the ORX group and the SAL group compared to the those of intact group. Patho-histological studies revealed that severe degenerative changes in testicular seminiferous tubules and massive infiltration of immune cells in SAL group. The present study confirmed that direct injection of hypertonic saline into the testis caused the equivalent biochemical changes in the accessory sex organs as shown in the orchidectomized animals. These results suggest that hypertonic saline injection model could be a useful castration model which can substitute for surgical castration when its safety is secured through further study in the future.

Effects of Calcium Administration on Parathyroid Gland, NaPi 2a Cotransporter and PTH1R in an Animal Model of the Andropause / EFEKTI TRETMANA KALCIJUMOM NA PARATIREOIDNU ŽLEZDU, NAPI 2A KOTRANSPORTER I PTH1R U ANIMALNOM MODELU ANDROPAUZE

Summary Background: Increased risk of osteoporotic bone fractures represents the adverse event in andropausal men. Due to diminished calcium absorption in elderly, its supplementa- tion is used for prevention and treatment of advanced-age osteoporosis. Methods: Sixteen-month-old Wistar rats were divided into sham-operated (SO), orchidectomized (Orx) and Ca2+- treated orchidectomized (Orx+Ca) groups. Ca2+ (28.55 mg/kg b.w.) was administered intramuscularly for 3 weeks, while the SO and Orx received vehicle alone. Parathyroid glands (PTG) were analyzed histomorphometrically, while the expression of NaPi 2a mRNA from kidneys was deter- mined by real time PCR. NaPi 2a and PTH1R abundance was detected immunofluorescently. Serum and urine parameters were determined biochemically. Results: The PTG volume was 15% (p&lt;0.05) greater in Orx rats than in the SO group. In Orx+Ca2+ animals, PTG vol- ume was decreased by 17% (p&lt;0.05), when compared to the Orx rats. Orchidectomy led to an increment of serum PTH of 13% (p&lt;0.05) compared to the SO group, while Orx+Ca decreased it by 10% (p&lt;0.05) when compared to Orx animals. The intensity of the NaPi 2a signal was reduced in Orx rats, in comparison with the SO group. Orx+Ca2+ treatment increased the abundance of NaPi 2a, compared to the Orx group. In Orx rats, the staining for PTH1R was stronger when compared to the SO group, while the Orx+Ca2+ treatment induced reduction of the PTH1R immunofluorescence, compared to Orx animals. Orchidectomy increased Pi urinary concentrations by 8% (p&lt;0.05), in comparison with the SO control, while in the Orx+Ca2+ group urinary Pi concentration was 5% lower (p&lt;0.05) than for the Orx rats. Conclusions: Our results indicate that Ca2+ administration reduces the PTH serum level and the presence of PTH1R, while increased abundance of NaPi 2a cotransporter posi- tively regulates Pi urine reabsorption in an animal model of the andropause.

Effects of PTH (1–84) on bone quality in a validated model of osteoporosis due to androgenic deprivation

Aim: The purpose of this study was to evaluate the effect of parathyroid hormone (PTH) (1–84) in a model of male osteoporosis induced by orchidectomy in rats.Methods: Six-month-old Wistar rats were used as follows: SHAM (simulated orchidectomy), orchidectomized (ORX), ORX + PTH1 (ORX and treated with 10 µg/Kg/d of PTH 1–84) and ORX + PTH2 (ORX and treated with 50 µg/Kg/d of PTH 1–84) over 3 months, with treatment beginning three months after orchidectomy.Results: Orchidectomy resulted in a decreased of femoral and lumbar bone mineral density (BMD), a worsening of trabecular and cortical microarchitecture and a decrease in biomechanical properties. Both doses of PTH (1–84) partially (low dose) or totally (high dose) restored the ORX-induced changes. Serum C-telopeptide of type I collagen/5b isoenzyme of tartrate-resistant acid phosphatase (CTX/TRAP) resorption index increased after orchidectomy. Osteocalcin (bone Gla protein; BGP) levels were not affected by orchidectomy. PTH (1–84) treatment did not produce any changes in the levels of CTX/TRAP with respect to the ORX group. BGP levels increased with PTH treatment.Conclusion: PTH (1–84) is able to restore the adverse effects of orchidectomy on bone as measured by BMD, microstructural and biomechanical properties and bone remodeling markers.

Hesperidin Prevents Androgen Deficiency‐induced Bone Loss in Male Mice

The purpose of this study was to examine whether hesperidin inhibits bone loss in androgen-deficient male mice. Male ddY mice aged 7 weeks underwent either a sham operation or orchidectomy (ORX) and were divided into five groups: a sham-operated group fed a control diet (Sham) based on AIN-93G formulation with corn oil instead of soy bean oil, an ORX group fed the control diet (ORX), a group fed the control diet containing 0.5% hesperidin (ORX + H), a group fed the control diet containing 0.7% α-glucosylhesperidin (ORX + αG), and a group fed the control diet containing 0.013% simvastatin (ORX + St). Four weeks after intervention, ORX mice showed a striking decrease in seminal vesicle weight, which was not affected by the administration of hesperidin, α-glucosylhesperidin, or simvastatin. Femoral BMD was significantly reduced by ORX, and bone loss was inhibited by the administration of hesperidin, α-glucosylhesperidin or simvastatin. Histomorphometric analysis showed that the bone volume and trabecular thickness were significantly lower, and the osteoclast number was higher in the distal femoral cancellous bone in the ORX group than in the Sham group, and these were normalized in the ORX + H, ORX + αG and ORX + St groups. These results indicate that hesperidin inhibited bone resorption and hyperlipidemia, in ORX mice, and the preventive effect was stronger than that observed in ovariectomized mice in our previous study.

Eurycoma longifolia upregulates osteoprotegerin gene expression in androgen- deficient osteoporosis rat model

BackgroundEurycoma longifolia (EL) has been shown recently to protect against bone calcium loss in orchidectomised rats, the model for androgen-deficient osteoporosis. The mechanism behind this is unclear but it may be related to its ability to elevate testosterone levels or it may directly affect bone remodeling. The aim of this study is to determine the mechanism involved by investigating the effects of EL extract on serum testosterone levels, bone biomarkers, biomechanical strength and gene expression of Receptor Activator of Nuclear Factor kappa-B ligand (RANKL), Osteoprotegerin (OPG) and Macrophage-Colony Stimulating Factor (MCSF) in orchidectomised rats.MethodsThirty-two male Sprague–Dawley rats were divided into: Sham-operated group (SHAM); orchidectomised-control group (ORX); orchidectomised and given 15 mg/kg EL extract (ORX + EL) and orchidectomised and given 8 mg/kg testosterone (ORX + T). The rats were treated for 6 weeks. The serum levels of testosterone, osteocalcin and C-terminal telopeptide of type I collagen (CTX) were measured using the ELISA technique. The femoral bones were subjected to biomechanical testing. The tibial bone gene expressions of RANKL, OPG and MCSF were measured using the branch DNA technique.ResultsThe post-treatment level of testosterone was found to be significantly reduced by orchiectomy (p < 0.05). Both ORX + EL and ORX + T groups have significantly higher post-treatment testosterone levels compared to their pre-treatment levels (p < 0.05). The bone resorption marker (CTx) was elevated after orchiectomy but was suppressed after treatment in the ORX + EL and ORX + T groups (p < 0.05). There was no significant finding for the femoral biomechanical parameters. The tibial OPG gene expression in the ORX group was significantly lower compared to the SHAM and ORX + EL groups (p < 0.05).ConclusionSupplementation with EL extract elevated the testosterone levels, reduced the bone resorption marker and upregulated OPG gene expression of the orchidectomised rats. These actions may be responsible for the protective effects of EL extract against bone resorption due to androgen deficiency.

Combined Effects ofEurycoma longifoliaand Testosterone on Androgen-Deficient Osteoporosis in a Male Rat Model

Androgen-deficient osteoporosis in men is treated with testosterone therapy, which is associated with side effects. Eurycoma longifolia (EL) is known to possess androgenic properties and has been reported to protect bone from androgen-deficient osteoporosis in experimental animal models. The present study aimed to determine the effectiveness of combination therapy of EL and testosterone (T) in treating androgen-deficient osteoporosis. Forty male Sprague-Dawley rats were divided into: sham-operated (SHAM), orchidectomized-control (ORX), orchidectomized with testosterone (ORX + T), orchidectomized with EL (ORX + EL), and orchidectomized with combined T and EL therapy (ORX + T + EL). EL was administered via oral gavages daily at the dose of 15 mg/kg. T was injected intramuscularly at 8 mg/kg and 4 mg/kg for the ORX + T and ORX + T + EL groups, respectively. Following 6 weeks of treatment, the osteocalcin levels of ORX + T and ORX + T + EL groups were significantly lower than the SHAM group (P < 0.05). The posttreatment CTX levels of ORX + T and ORX + T + EL groups were significantly lower than their pretreatment levels (P < 0.05). Biomechanically, the strain parameter of the ORX + T + EL group was significantly higher than the ORX group (P < 0.05). Thus, the combination therapy of EL and low-dose T has potential for treatment of androgen-deficient osteoporosis. The lower T dose is beneficial in reducing the sideeffects of testosterone therapy.

Daidzein effects on ACTH cells: immunohistomorphometric and hormonal study in an animal model of the andropause.

Daidzein is a potential natural alternative to estradiol during therapy of some malignancies in men. Besides weak inhibition of tyrosine kinase activity, daidzein has a sizeable inhibitory effect on calcium channels. The aim of this study was to examine the effects of daidzein on the immunohistomorphometric features of pituitary adrenocorticotropes (ACTH cells) and circulating levels of ACTH and corticosterone, in comparison with estradiol, in an animal model of the andropause. Sixteen-month-old Wistar rats were divided into sham operated (SO), orchidectomized (Orx), estradiol treated orchidectomized (Orx+E) and daidzein treated orchidectomized (Orx+D) groups. Estradiol (0.625 mg/kg/day) and daidzein (30 mg/kg/day) were administered subcutaneously for three weeks, while the SO and Orx groups received the vehicle alone. ACTH cells were identified by the peroxidase-antiperoxidase (PAP) immunohistochemical procedure. Peripheral circulating concentrations of ACTH and corticosterone were measured by immunoassay. Orchidectomy reduced (p<0.05) the cell volume and volume density of adrenocorticotropes by 11% and 16%, respectively, in comparison to SO rats. In Orx+E rats, the volume density of ACTH cells decreased (p<0.05) by 25%, but the circulating level of ACTH increased (p<0.05) by 29%, compared to Orx rats. Daidzein treatment significantly decreased (p<0.05): volume density of ACTH cells, circulating ACTH and corticosterone by 24%, 48% and 33%, respectively, compared to the Orx group. In conclusion, this study revealed that daidzein negatively modulated the immunohistomorphometric features of ACTH cells and, unlike estradiol, decreased ACTH and corticosterone secretion, in an animal model of the andropause.

Vitamin E dose-dependently reduces aortic fatty lesion formation in orchidectomized aged rats

Although the cardioprotective effects of supplemental doses of vitamin E have been investigated in several conditions, its role in gonadectomy- induced fatty lesion formation is unclear. The present study was designed to examine the efficacy of vitamin E in a dose-dependent manner on indices of oxidative stress and in preventing the formation of aortic fatty lesions in orchidectomized (Orx) aged rats. Forty 12-month old male Sprague-Dawley rats were either sham-operated (Sham) or Orx and fed a semi-purified control diet for 120 days. Thereafter, rats were assigned to four treatment groups (n=10): Sham and one Orx group received 75 IU vitamin E and served as controls, and the other two Orx groups received either 250 or 500 IU vitamin E per kg diet for 90 days. Vitamin E at the highest dose (500 IU) was able to lower serum total cholesterol by 16% and significantly increase superoxide dismutase by 9% compared to Orx controls. Similarly, this dose was able to significantly reduce the development of atherosclerotic lesion formation and aortic fatty streak area by 93% compared to Orx controls. The findings of this study suggest that dietary vitamin E supplementation in Orx aged rats provide anti-atherogenic effects, in part, due to vitamin E's antioxidative properties. Clinical studies are needed to confirm whether supplemental doses of vitamin E can prevent the development of atherosclerosis in older men particularly with low testosterone level.

Daidzein administration positively affects thyroid C cells and bone structure in orchidectomized middle-aged rats

Thyroid C cells hormone, calcitonine, inhibits bone resorption. We have demonstrated that daidzein treatment of orchidectomized rats (model for osteoporosis) stimulated C cells and increased trabecular bone mass. These results suggest that, besides direct action, daidzein may also affect bone structure indirectly through enhancement of thyroid C cell activity. Thyroid C cells produce calcitonin (CT) which acts as an inhibitor of bone resorption. In this study, the influence of daidzein treatment on thyroid C cells, bone structure, and bone function in orchidectomized (Orx) middle-aged rats was investigated. Sixteen-month-old Wistar rats were divided into Orx and sham-operated (SO) groups. Half the Orx rats were given subcutaneous injections of daidzein (30 mg/kg b.w./day) for 3 weeks. CT-immunopositive thyroid C cells were morphometrically analyzed. The metaphyseal region of the proximal tibia was measured histomorphometrically, and cancellous bone area (B.Ar), trabecular thickness (Tb.Th), trabecular number (Tb.N), and trabecular separation (Tb.Sp) were calculated. Serum samples were analyzed for CT and osteocalcin (OC), calcium (Ca) and phosphorus concentrations, and urine samples for Ca levels. Treatment of Orx animals with daidzein significantly increased volume of C cells compared to the Orx rats. Daidzein also enhanced B.Ar, Tb.Th, and Tb.N and reduced Tb.Sp. The serum OC and urinary Ca concentrations decreased significantly in comparison with the Orx group. These findings indicate that daidzein treatment stimulates thyroid C cells, increase trabecular bone mass, and decrease bone turnover in Orx middle-aged rats, which is the model of male osteoporosis.

Genistein-Induced Histomorphometric and Hormone Secreting Changes in the Adrenal Cortex in Middle-Aged Rats

The soybean phytoestrogen, genistein, is increasingly consumed as an alternative therapeutic for age-related diseases, namely cardiovascular conditions, cancer and osteoporosis. Besides estrogenic/antiestrogenic action, this isoflavone exerts a prominent inhibitory effect on tyrosine kinase and the steroidogenic enzyme families, thus affecting hormonal homeostasis. The aim of this study was to examine the effects of genistein on: histomorphometric features of the adrenal cortex, blood concentrations of aldosterone, corticosterone and dehydroepiandrosterone (DHEA) and adrenal tissue corticosterone content in orchidectomized middle-aged male rats. Sixteen-month-old Wistar rats were divided into sham-operated (SO), orchidectomized (Orx) and genistein-treated orchidectomized (Orx+G) groups. Genistein (30 mg/kg/day) was administered subcutaneously for three weeks, while the control groups received the vehicle alone. The adrenal cortex was analysed histologically and morphometrically. Circulating concentrations of aldosterone, corticosterone and DHEA, as well as adrenal tissue corticosterone levels, were determined by immunoassay. When compared to the SO group, orchidectomy decreased the ZG and ZR cell volume by 43% and 29%, respectively (P<0.05). Serum concentrations of aldosterone and DHEA were markedly lower [13% and 41%, respectively (P<0.05)], while serum and adrenal tissue levels of corticosterone did not change after orchidectomy. Orchidectomy followed by genistein treatment increased the ZG, ZF and ZR cell volume by 54%, 34% and 77%, respectively (P<0.05), compared to the untreated orchidectomized group. Histological analysis revealed noticeable vacuolization of the ZG and ZF cells in the Orx+G group. Serum aldosterone and corticosterone concentrations together with adrenal tissue corticosterone were 47%, 31% and 44% lower, respectively (P<0.05), whereas serum DHEA concentration was 342% higher (P<0.05) in this group in comparison with the Orx group. This study shows that in orchidectomized middle-aged rats, genistein can cause the shunting of metabolic pathways in the adrenals, supporting DHEA secretion and inhibiting corticosterone and aldosterone secretion.

Grapefruit pulp increases antioxidant status and improves bone quality in orchidectomized rats

Objective Orchidectomy causes oxidative stress and increases the incidence of osteoporosis. The objective of this research was to evaluate whether eating grapefruit pulp (GP) modifies antioxidant status and reduces osteoporosis in orchidectomized rats. Methods Fifty-six 90-d-old male Sprague-Dawley rats were randomized into two groups: sham-control group ( n = 14) and orchidectomized (ORX) group ( n = 42). The orchidectomized group was equally divided among the following three treatments: orchidectomy, orchidectomy + 5.0% GP, and orchidectomy + 10% GP. At the termination of the study (day 60), all rats were euthanized and the plasma was collected for antioxidant status and indices of bone turnover. Bone quality and mineral contents in the bone, urine, and feces were evaluated. Results Orchidectomy lowered ( P < 0.05) antioxidant status, bone quality, bone mineral contents and elevated ( P < 0.05) indices of bone turnover, urinary deoxypyridinoline, and fecal calcium excretion. In contrast to the ORX group, independent of dosage, antioxidant status, bone density, and delayed time-induced femoral fracture were higher ( P < 0.05) in the GP groups, whereas fecal calcium excretion and urinary deoxypyridinoline excretion were lowered ( P < 0.05). GP dose-dependently slowed down bone turnover ( P < 0.05), elevated bone calcium and magnesium contents ( P < 0.05), tended to lower urinary excretion of magnesium, and numerically improved bone strength. Conclusion The beneficial effects of eating red grapefruit on bone quality of ORX rats is due to bone mineral deposition and slowed-down bone turnover.

Grapefruit Juice Modulates Bone Quality in Rats

Hypogonadism and oxidative stress increase the risk for developing osteoporosis. The objective of this research was to evaluate the efficacy of drinking grapefruit juice on bone quality in orchidectomized (ORX) and non-ORX rats. Fifty-six 90-day-old male Sprague-Dawley rats were equally divided into four groups--non-ORX rats (sham), sham + grapefruit juice, ORX, and ORX + grapefruit juice--and treated for 60 days. Thereafter, all rats were sacrificed to determine the plasma antioxidant status, insulin-like growth factor I (IGF-I), and indices of bone turnover, bone quality, and calcium and magnesium concentrations in the bone, urine, and feces. Orchidectomy decreased (P < .05) antioxidant status, bone quality, and bone mineral contents and increased (P < .05) indices of bone turnover, urinary deoxypridinoline, calcium, and magnesium, and fecal calcium excretions. In contrast to the ORX group, ORX rats that drank grapefruit juice had an increase (P < .05) in antioxidant status, bone density, and bone mineral contents, delayed femoral fracture, and slowed down (P < .05) bone turnover rate and tended to have a decrease (P = .08) in urinary deoxypridinoline. In sham-treated animals, drinking grapefruit juice increased (P < .05) bone density and tended to increase the femoral strength. The concentration of IGF-I in the plasma was not affected across treatments. In conclusion, drinking grapefruit juice positively affected bone quality by enhancing bone mineral deposition in ORX rats and by improving bone density in non-ORX rats via an undefined mechanism.

A BRIEF COMMUNICATION

Nutritional supplements containing soybean phytoestrogens, the isoflavones genistein (G) and daidzein (D), are increasingly used as alternative therapy for osteoporosis, cancer, and cardiovascular and other diseases with a frequency that increases with advancing age. In this study we examined the effects of subcutaneous administration of either G or D on serum lipid levels in orchidectomized (Orx) and intact (IA) middle-aged male rats, which are experimental models of andropause. Sixteen-month-old Wistar rats were treated with 10 mg/kg and 30mg/kg of either G or D. The control groups received testosterone, estradiol, or vehicle for 3 weeks, after which the total serum cholesterol (TC), low-density lipoprotein (LDL-C), high-density lipoprotein (HDL-C), and total triglycerides (TT) were measured. Compared with the matching vehicle-treated controls, the higher doses of G and D and testosterone treatment significantly ( P &lt; 0.05) lowered the TC and lipoprotein cholesterol levels. The greatest effect was observed regarding LDL-C in both Orx and IA males after G and D treatments, in which LDL-C decreased by more than 30%. The lower isoflavone doses induced a significant cholesterol-lowering effect ( P &lt; 0.05) only in the Orx group. Like the estradiol treatment, the higher doses of G and D increased the TT levels in both rat models by more than 50% ( P &lt; 0.05). The lower doses of isoflavones increased TT only in the Orx group. In male middle-aged rats, injections of higher doses of G and D decreased the serum cholesterol levels, as did testosterone injection, and brought about an increase in serum triglycerides similar to that observed after estradiol treatment.

Vitamin E Does Not Modulate Plasma Lipid Profile or C-Reactive Protein Despite Suppressing Oxidative Stress in Orchiectomized Rats

Vitamin E is known to improve antioxidant status and to prevent lipoprotein oxidation. However, the effect of vitamin E on other cardiovascular risk factors, including C-reactive protein (CRP) and lipid profile status, in orchiectomized rats is unknown. In the present study, 32 1-year-old male rats were randomized into two groups: a sham-control group (n = 8) and an orchiectomized group (n = 24). The orchiectomized group was divided into three groups of eight and assigned to one of the following treatments: orchiectomy (ORX), ORX + vitamin E mixture (65.6 mg/kg) diet, or ORX + vitamin E mixture (656 mg/kg) diet. For 120 days all four groups consumed a basal AIN-93M diet, while the vitamin E groups ate diets containing an additional vitamin E mixture. Four months after the study began, all the rats were killed, the blood was collected, and the plasma was assayed for antioxidant status, CRP, lipid profile, and indices of peroxidation. ORX decreased (P < .05) the plasma antioxidant status, superoxide dismutase (SOD) activity, and CRP level and increased (P < .05) the plasma malondialdeyde, nitrite, and lipid profile compared with that of the sham-control group. In contrast to the ORX group, supplementation with vitamin E mixture increased (P < .05) plasma antioxidant status and dose-dependently increased (P < .05) SOD activity, while the vitamin E decreased (P < .05) plasma malondialdeyde and nitrite. The vitamin E mixture had no effect on CRP or on lipid profiles when compared to the orchiectomized rats. In conclusion, vitamin E appears to reduce oxidative stress without modulating lipid profile or inflammatory response.