The aim of this study was to determine the effects of palm oil-derived vitamin E on glucocorticoid-induced osteoporosis. Three-month old male Wistar rats were adrenalectomised to remove circulating glucocorticoids. The animals were then administered with Dexamethasone 120 µg/kg body weight/day. Treatment with palm vitamin E 60 mg/kg body weight/day was given simultaneously. The results showed that palm vitamin E prevented the loss in regional and whole body bone mineral density seen in the Dexamethasone treated animals. Palm vitamin E improved femoral length and calcium content in the Dexamethasone treated animals. The results confirmed that palm oil-derived vitamin E was effective in preventing glucocorticoid-induced osteoporosis.
1. Free radicals generated by ferric nitrilotriacetate (FeNTA) can activate osteoclastic activity and this is associated with elevation of the bone resorbing cytokines interleukin (IL)-1 and IL-6. In the present study, we investigated the effects of 2 mg/kg FeNTA (2 mg iron/kg) on the levels of serum IL-1 and IL-6 with or without supplementation with a palm oil tocotrienol mixture or alpha-tocopherol acetate in Wistar rats. 2. The FeNTA was found to elevate levels of IL-1 and IL-6. Only the palm oil tocotrienol mixture at doses of 60 and 100 mg/kg was able to prevent FeNTA-induced increases in IL-1 (P < 0.01). Both the palm oil tocotrienol mixture and alpha-tocopherol acetate, at doses of 30, 60 and 100 mg/kg, were able to reduce FeNTA-induced increases in IL-6 (P < 0.05). Therefore, the palm oil tocotrienol mixture was better than pure alpha-tocopherol acetate in protecting bone against FeNTA (free radical)-induced elevation of bone-resorbing cytokines. 3. Supplementation with the palm oil tocotrienol mixture or alpha-tocopherol acetate at 100 mg/kg restored the reduction in serum osteocalcin levels due to ageing, as seen in the saline (control) group (P < 0.05). All doses of the palm oil tocotrienol mixture decreased urine deoxypyridinoline cross-link (DPD) significantly compared with the control group, whereas a trend for decreased urine DPD was only seen for doses of 60 mg/kg onwards of alpha-tocopherol acetate (P < 0.05). 4. Bone histomorphometric analyses have shown that FeNTA injections significantly lowered mean osteoblast number (P < 0.001) and the bone formation rate (P < 0.001), but raised osteoclast number (P < 0.05) and the ratio of eroded surface/bone surface (P < 0.001) compared with the saline (control) group. Supplementation with 100 mg/kg palm oil tocotrienol mixture was able to prevent all these FeNTA-induced changes, but a similar dose of alpha-tocopherol acetate was found to be effective only for mean osteoclast number. Injections of FeNTA were also shown to reduce trabecular bone volume (P < 0.001) and trabecular thickness (P < 0.05), whereas only supplementation with 100 mg/kg palm oil tocotrienol mixture was able to prevent these FeNTA-induced changes.
Nicotine has been shown to exert negative effects on bone. This study determined whether vitamin E supplementation is able to repair the nicotine-induced adverse effects in bone.
The effects of nicotine administration on bone-resorbing cytokines, cotinine, and bone histomorphometric parameters were studied in 21 Sprague-Dawley male rats. Rats aged 3 months and weighing 250-300 g were divided into three groups. Group 1 was the baseline control (BC), which was killed without treatment. The other two groups were the control group (C) and the nicotine-treated group (N). The N group was treated with nicotine 7 mg/kg body weight and the C group was treated with normal saline only. Treatment was given by intraperitoneal injection for 6 days/week for 4 months. The rats were injected intraperitoneally with calcein 20 mg/kg body weight at day 9 and day 2 before they were killed. ELISA test kits were used to measure the serum interleukin-1 (IL-1), interleukin-6 (IL-6), and cotinine (a metabolite of nicotine) levels at the beginning of the study and upon completion of the study. Histomorphometric analysis was done on the metaphyseal region of the trabecular bone of the left femur by using an image analyzer. Biochemical analysis revealed that nicotine treatment for 4 months significantly increased the serum IL-1, IL-6, and cotinine levels as compared to pretreatment levels. In addition, the serum cotinine level was significantly higher in the N group than in the C group after 4 months treatment. Histomorphometric analysis showed that nicotine significantly decreased the trabecular bone volume (BV/TV), trabecular thickness (Tb.Th), double-labeled surface (dLS/BS), mineralizing surface (MS/BS), mineral appositional rate (MAR), and bone formation rate (BFR/BS), while causing an increase in the single-labeled surface (sLS/BS), osteoclast surface (Oc.S/BS), and eroded surface (ES/BS) as compared to the BC and C groups. In conclusion, treatment with nicotine 7 mg/kg for 4 months was detrimental to bone by causing an increase in the bone resorbing cytokines and cotinine levels. Nicotine also exerted negative effects on the dynamic trabecular histomorphometric parameters.
Palm oil is shown to have antioxidant, anticancer and cholesterol lowering effects. It is resistant to oxidation when heated compared to other frying oils such as soy oil. When a frying oil is heated repeatedly, it forms toxic degradation products, such as aldehydes which when consumed, may be absorbed into the systemic circulation. We have studied the effects of taking soy or palm oil that were mixed with rat chow on the bone histomorphometric parameters of ovariectomised rats. Female Sprague-Dawley rats were divided into eight groups: (1) normal control group; (2) ovariectomised-control group; (3) ovariectomised and fresh soy oil; (4) ovariectomised and soy oil heated once; (5) ovariectomised and soy oil heated five times; (6) ovariectomised and fresh palm oil; (7) ovariectomised and palm oil heated once; (8) ovariectomised and palm oil heated five times. These oils were mixed with rat chow at weight ratio of 15:100 and were given to the rats daily for six months. Ovariectomy had caused negative effects on the bone histomorphometric parameters. Ingestion of both fresh and once-heated oils, were able to offer protections against the negative effects of ovariectomy, but these protections were lost when the oils were heated five times. Soy oil that was heated five times actually worsens the histomorphometric parameters of ovariectomised rats. Therefore, it may be better for postmenopausal who are at risk of osteoporosis to use palm oil as frying oil especially if they practice recycling of frying oils.
The aim of this study was to investigate the effects of vitamin E on the levels of lipid peroxidation and antioxidant enzymes in rat bones. Fifty-six normal male Sprague-Dawley rats, aged 3 months, were randomly divided into seven groups with eight rats in each group. The age-matched control group was given the vehicle olive oil, by oral gavage daily. Six of the treatment groups received either palm tocotrienol or pure alpha-tocopherol at the dose of 30, 60 or 100 mg/kg body weight, by oral gavage daily, 6 days a week for 4 months. Thiobarbituric acid-reactive substance (TBARS) that is an index to measure the level of lipid peroxidation and the antioxidant enzymes, glutathione peroxidase and superoxide dismutase levels were measured in the femur at the end of the study. Palm tocotrienol at the dose of 100 mg/kg body weight significantly reduced the TBARS level in the femur with a significant increase in glutathione peroxidase activity compared to the age-matched control group. These were not observed in the alpha-tocopherol groups. Palm tocotrienol was more effective than pure alpha-tocopherol acetate in suppressing lipid peroxidation in bone. Palm tocotrienol showed better protective effect against free radical damage in the femur compared to alpha-tocopherol. This study suggests that palm tocotrienol plays an important role in preventing imbalance in bone metabolism due to free radicals.
This study was conducted to determine the effectiveness of three forms of vitamin E supplements following nicotine treatment on bone histomorphometric parameters in an adult male rat model. Rats were divided into seven groups: baseline (B, killed without treatment), control (C, normal saline for 4 months), nicotine (N, nicotine for 2 months), nicotine cessation (NC), tocotrienol-enhanced fraction (TEF), gamma-tocotrienol (GTT), and alpha-tocopherol (ATF). Treatments for the NC, TEF, GTT, and ATF groups were performed in two phases. For the first 2 months they were given nicotine (7 mg/kg), and for the following 2 months nicotine administration was stopped and treatments with respective vitamin E preparations (60 mg/kg) were commenced except for the NC group, which was allowed to recover without treatment. Rats in the N and NC groups had lower trabecular bone volume, mineral appositional rate (MAR), and bone formation rate (BFR/BS) and higher single labeled surface and osteoclast surface compared to the C group. Vitamin E treatment reversed these nicotine effects. Both the TEF and GTT groups, but not the ATF group, had a significantly higher trabecular thickness but lower eroded surface (ES/BS) than the C group. The tocotrienol-treated groups had lower ES/BS than the ATF group. The GTT group showed a significantly higher MAR and BFR/BS than the TEF and ATF groups. In conclusion, nicotine induced significant bone loss, while vitamin E supplements not only reversed the effects but also stimulated bone formation significantly above baseline values. Tocotrienol was shown to be slightly superior compared to tocopherol. Thus, vitamin E, especially GTT, may have therapeutic potential to repair bone damage caused by chronic smoking.
Vitamin E is found to reverse the effects of nicotine on bone and this study aimed to determine its mechanism. Male Sprague Dawley rats were divided into four groups and treated for 3 months: Group 1 was the control group (RC). Groups 2 (N), 3 (N+TT) and 4 (N+ATF) received nicotine 7 mg/kg throughout the treatment period. In addition, groups 3 and 4 received tocotrienol 60 mg/kg and alpha-tocopherol 60 mg/kg respectively during months 2 and 3. Parameters measured were serum osteoprotegerin (OPG), serum receptor activator of nuclear factor kappa B ligand (RANKL), femoral and lumbar bone calcium content and body weight. Nicotine did not affect OPG or RANKL levels but reduced bone calcium content suggesting the calcium loss is not due to increase osteoclastogenesis. OPG was increased in N+ATF while RANKL was slightly increased in N+TT. Both vitamin E supplements restored bone calcium loss induced by nicotine. Nicotine impaired weight gain in all treatment groups starting week 4 however, N+TT group was comparable to RC from week 6 onwards. Bone protective effects of ATF, but not TT, may be partly due to inhibition of osteoclastogenesis.
Recently, vitamin E has been found to promote the bone structure of nicotine-treated rats well above their baseline values, thus suggesting that vitamin E may have some anabolic action. A bone anabolic agent acts by improving the bone structure leading to stronger bone. To assess the possible anabolic action vitamin E on bone, we supplemented alpha-tocopherol (ATF) or gamma-tocotrienol (GTT) at 60 mg/kg or vehicle [normal control (NC) group] for 4 months to normal male rats and measured their bone structure and biomechanical properties. Histomorphometric analysis revealed that vitamin E-supplemented rats have better trabecular volume, thickness, number, and separation than rats receiving vehicle only. For the first time we reported that GTT improves all the parameters of bone biomechanical strength, while ATF only improved some of the parameters compared to the NC group. Vitamin E supplementation, especially with the gamma isomer, improves bone structure, which contributed to stronger bone. Therefore, vitamin E has the potential to be used as an anabolic agent to treat osteoporosis or as bone supplements for young adults to prevent osteoporosis in later years.
Nicotine is a major alkaloid of tobacco, which can increase free radical formation, leading to osteoporosis. The effects of nicotine administration and cessation on bone histomorphometry and biomarkers were studied in 28 Sprague-Dawley male rats. Rats aged 3 months and weighing 250-300 g were divided into four groups: control (C, normal saline for 4 months), nicotine for 2 months (N2), nicotine for 4 months (N4), and nicotine cessation (NC). The NC group was given nicotine for the first 2 months and then allowed to recover for the following 2 months without nicotine. Histomorphometric analysis was done using an image analyzer. ELISA kits were used to measure serum osteocalcin (bone formation marker) and pyridinoline (PYD, bone resorption marker) levels at month 0, month 2, and month 4. All test groups showed a significant decrease in BV/TV, Ob.S/BS, dLS/BS, MAR, BFR/BS, and osteocalcin levels and an increase in sLS/BS and PYD levels compared to group C. No significant differences were observed in all parameters measured among the test groups, except for MAR and BFR/BS. In conclusion, nicotine administration at a dose of 7 mg/kg for 2 and 4 months has detrimental effects on bone metabolism. Nicotine administration at 7 mg/kg for 2 months is sufficient to produce significant effects on bone histomorphometric parameters and biomarkers. In addition, prolonging the treatment for another 2 months did not show any significant differences. Cessation of nicotine for 2 months did not reverse the effects.
AIM OF THE STUDY: Postmenopausal osteoporosis is mainly treated with estrogen replacement therapy (ERT). However, ERT causes side effects, mainly breast cancer, uterine cancer and thromboembolic problems. Labisia pumila var. arata (LPva), a herb with phytoestrogenic effects has the potential to be used as an alternative agent to ERT. This study was conducted to determine the effects of LPva on bone biochemical markers and bone calcium content in ovariectomised rats.
MATERIALS AND METHODS: Thirty two Wistar rats were divided into 4 groups, with 8 rats in each group. The first group was sham operated (Sham), the second group was ovariectomised (OVX), the third (LPva) and fourth group (ERT) were also ovariectomised and given LPva 17.5 mg/kg and Premarin(®) 64.5 μg/kg, respectively. Blood samples were taken before and after treatment to measure osteocalcin and C-terminal telopeptide of type 1 collagen levels using ELISA while the fifth lumbar bone samples were taken to measure bone calcium content using the Atomic Absorption Spectrophotometer (AAS).
RESULTS: The osteocalcin levels were significantly higher in both the LPva and ERT groups compared to the OVX group. The CTX levels were significantly lower in both the LPva and ERT groups compared to the OVX group. However, only the ERT group had significantly higher bone calcium level compared to the OVX group.
CONCLUSION: The supplementation of 17.5 mg/kg of LPva to ovariectomised rats for 8 weeks was able to prevent the changes in bone biochemical markers but failed to prevent the bone calcium loss induced by ovariectomy.
AIM: To determine if baseline vitamin D levels would influence the gain in bone mineral density (BMD) in female systemic lupus erythematosus (SLE) patients on corticosteroids (CS) taking bone-active medication.
METHOD: Premenopausal SLE patients participating in a trial assessing the efficacy of calcium alone, calcitriol and calcium, and alendronate and calcium, on BMD in patients on CS, were studied. Patients were randomly allocated to the treatment groups at the start of the study and followed up for 2 years. Serum 25-hydroxy vitamin D [25(OH)D] was measured at baseline.
RESULTS: Thirty-eight patients were studied. One (2%) patient had osteoporosis, nine (24%) had osteopenia and all others had normal BMD. The mean baseline 25(OH)D levels were 21.6 ± 4.6 ng/mL (± 1 SD). Twelve (32%) patients had vitamin D deficiency [25(OH)D < 20 ng/mL]. There was a significant negative correlation between SLEDAI scores and 25(OH)D levels, that is, patients with high SLEDAI scores had significantly lower 25(OH)D levels (P = 0.033). Left femoral neck BMD was significantly lower in the deficient compared to insufficient group (P = 0.042). There was a trend toward better BMD gain at 2 years in the vitamin D insufficient compared to the deficient group, which did not reach statistical significance.
CONCLUSION: This study showed that in female SLE patients, low vitamin D levels are associated with higher disease activity and suggests that patients who have higher vitamin D levels have a better BMD response during treatment with bone-active agents.
Rapid onset of bone loss is a frequent complication of systemic glucocorticoid therapy which may lead to fragility fractures. Glucocorticoid action in bone depends upon the activity of 11β-hydroxysteroid dehydrogenase type 1 enzyme (11β-HSD1). Regulations of 11β-HSD1 activity may protect the bone against bone loss due to excess glucocorticoids. Glycyrrhizic acid (GCA) is a potent inhibitor of 11β-HSD. Treatment with GCA led to significant reduction in bone resorption markers. In this study we determined the effect of GCA on 11β-HSD1 activity in bones of glucocorticoid-induced osteoporotic rats. Thirty-six male Sprague-Dawley rats (aged 3 months and weighing 250-300 g) were divided randomly into groups of ten. (1) G1, sham operated group; (2) G2, adrenalectomized rats administered with intramuscular dexamethasone 120 μg/kg/day and oral vehicle normal saline vehicle; and (3) G3, adrenalectomized rats administered with intramuscular dexamethasone 120 μg/kg/day and oral GCA 120 mg/kg/day The results showed that GCA reduced plasma corticosterone concentration. GCA also reduced serum concentration of the bone resorption marker, pyridinoline and induced 11β-HSD1 dehydrogenase activity in the bone. GCA improved bone structure, which contributed to stronger bone. Therefore, GCA has the potential to be used as an agent to protect the bone against glucocorticoid induced osteoporosis.
Cosmos caudatus (ulam raja) contains high mineral content and possesses high antioxidant activity which may be beneficial in bone disorder such as postmenopausal osteoporosis. The effects of C. caudatus on bone metabolism biomarkers in ovariectomized rats were studied. 48 Sprague-Dawley rats aged three months were divided into 6 groups. One group of rats was sham-operated while the remaining rats were ovariectomized. The ovariectomized rats were further divided into 5 groups: the control, three groups force-fed with C. caudatus at the doses of 100mg/kg, 200mg/kg or 300mg/kg and another group supplemented with calcium 1% ad libitum. Treatments were given 6 days per week for a period of eight weeks. Blood samples were collected twice; before and after treatment. Parameters measured were bone resorbing cytokine; interleukin-1 and the bone biomarkers; osteocalcin and pyridinoline. Serum IL-1 and pyridinoline levels were significantly increased in ovariectomized rats. Supplementation of C. caudatus was able to prevent the increase of IL-1 and pyridinoline in ovariectomized rats. Besides that, C. caudatus showed the same effect as calcium 1% on biochemical parameters of bone metabolism in ovariectomized rats. In conclusion, Cosmos caudatus was as effective as calcium in preventing the increase in bone resorption in ovariectomized rats.
Fracture healing is a process of recovering injured bone tissue forms and functions. Osteoporosis can delay the healing process, which contributes to personal suffering and loss of activities. Osteoporosis patients tend to lose bone mass at the metaphyseal region which require treatment to increase bone mass. Postmenopausal osteoporosis is the most common osteoporosis that occurs in women which subsequently resulted in fractures even under slight trauma. Estrogen Replacement Therapy (ERT), the recommended therapy for postmenopausal osteoporosis, is associated with higher risk of breast cancer, ovarian cancer and cardiovascular diseases. As osteoporotic fractures are becoming a public health issue, alternative treatment is now being thoroughly explored. The potential agent is statins, the HMG-CoA reductase inhibitor which is widely used for hypercholesterolemia treatment. Statins have been found to increase bone mass by stimulation of Bone morphogenetic protein-2 (BMP-2) expression and Vascular Endothelial Growth Factor (VEGF) production. However, these bone forming effects were achieved at very high systemic doses. Therefore, studies on locally applied statins are required to further explore the ability of statins to stimulate bone formation at acceptable doses for better fracture healing. This review highlights the animal and clinical studies on fracture healing promotions by statins and the mechanisms involved.
Osteoporosis is a common complication observed in rheumatoid arthritis (RA). Accelerated bone loss is always a matter of concern. The pathogenesis of RA may be important for better understanding of the bone loss. The mechanism involved in the bone loss in RA is not well understood although cytokines such as interleukin 1 and tumour necrosis factor α (TNF α) have been strongly implicated. TNF α antagonists have revolutionised the treatment of RA in the recent years. Beyond the control of disease activity in RA, accumulating evidence suggests that this form of therapy may provide beneficial effects to the bone metabolism and remodeling. An extensive search of the literature was performed in the Medline, Scopus and EBSCO databases to evaluate the documented research on the effects of TNF α antagonists in RA on bone mineral density and bone turnover markers. The available data based on our systematic review, depict a significant association between TNF α antagonists treatment and suppression of bone resorption.
Biodegradable metals such as magnesium, iron and their alloys have been known as potential materials for temporary medical implants. However, most of the studies on biodegradable metals have been focusing on optimizing their mechanical properties and degradation behavior with no emphasis on improving their bioactivity behavior. We therefore investigated the possibility of improving iron biodegradation rate and bioactivity by incorporating various bioactive bioceramics. The iron-based bioceramic (hydroxyapatite, tricalcium phosphate and biphasic calcium phosphate) composites were prepared by mechanical mixing and sintering process. Degradation studies indicated that the addition of bioceramics lowered the corrosion potential of the composites and slightly increased their corrosion rate compared to that of pure iron. In vitro cytotoxicity results showed an increase of cellular activity when rat smooth muscle cells interacted with the degrading composites compared to pure iron. X-ray radiogram analysis showed a consistent degradation progress with that found in vivo and positive tissue response up to 70 days implantation in sheep animal model. Therefore, the iron-based bioceramic composites have the potential to be used for biodegradable bone implant applications.
Recent studies have found conflicting evidence on the role of α-tocopherol (αTF) on bone health. This nonsystematic review aimed to summarize the current evidence on the effects of αTF on bone health from cell culture, animal, and human studies in order to clarify the role of αTF on bone health. Our review found that αTF exerted beneficial, harmful or null effects on bone formation cells. Animal studies generally showed positive effects of αTF supplementation on bone in various models of osteoporosis. However, high-dose αTF was possibly detrimental to bone in normal animals. Human studies mostly demonstrated a positive relationship between αTF, as assessed using high performance liquid chromatography and/or dietary questionnaire, and bone health, as assessed using bone mineral density and/or fracture incidence. Three possible reasons high dosage of αTF can be detrimental to bone include its interference with Vitamin K function on bone, the blocking of the entry of other Vitamin E isomers beneficial to bone, and the role of αTF as a prooxidant. However, these adverse effects have not been shown in human studies. In conclusion, αTF may have a dual role in bone health, whereby in the appropriate doses it is beneficial but in high doses it may be harmful to bone.
Postmenopausal osteoporosis can be associated with oxidative stress and deterioration of antioxidant enzymes. It is mainly treated with estrogen replacement therapy (ERT). Although effective, ERT may cause adverse effects such as breast cancer and pulmonary embolism. Labisia pumila var. alata (LP), a herb used traditionally for women's health was found to protect against estrogen-deficient osteoporosis. An extensive study was conducted in a postmenopausal osteoporosis rat model using several LP doses and duration of treatments to determine if anti-oxidative mechanisms were involved in its bone protective effects. Ninety-six female Sprague-Dawley rats were randomly divided into six groups; baseline group (BL), sham-operated (Sham), ovariectomised control (OVXC), ovariectomised (OVX) and given 64.5 μg/kg of Premarin (ERT), ovariectomised and given 20 mg/kg of LP (LP20) and ovariectomised and given 100 mg/kg of LP (LP100). The groups were further subdivided to receive their respective treatments via daily oral gavages for three, six or nine weeks of treatment periods. Following euthanization, the femora were dissected out for bone oxidative measurements which include superoxide dismutase (SOD), glutathione peroxidase (GPx) and malondialdehyde (MDA) levels.
Morphological surface modifications have been reported to enhance the performance of biomedical implants. However, current methods of introducing graded porosity involves postprocessing techniques that lead to formation of microcracks, delamination, loss of fatigue strength, and, overall, poor mechanical properties. To address these issues, we developed a microwave sintering procedure whereby pure titanium powder can be readily densified into implants with graded porosity in a single step. Using this approach, surface topography of implants can be closely controlled to have a distinctive combination of surface area, pore size, and surface roughness. In this study, the effect of various surface topographies on in vitro response of neonatal rat calvarial osteoblast in terms of attachment and proliferation is studied. Certain graded surfaces nearly double the chance of cell viability in early stages (∼one month) and are therefore expected to improve the rate of healing. On the other hand, while the osteoblast morphology significantly differs in each sample at different periods, there is no straightforward correlation between early proliferation and quantitative surface parameters such as average roughness or surface area. This indicates that the nature of cell-surface interactions likely depends on other factors, including spatial parameters.