الفهرس 
Bone Health and OsteoporosisOnly 14 pages are availabe for public view
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Abstract
Osteoporosis is a skeletal disorder characterized by reduction of bone mineral density and bone strength leading to increased risk of fractures. It is silent disease characterized by deterioration of bone tissue, with a consequent increase in bone fragility and susceptibility to fracture. Glucocorticoid (GC) induced osteoporosis is the most common cause of secondary osteoporosis.
This study was aimed to investigate the effect of avocado and flaxseed oils and their synergistic effect on osteoporosis induced by GC in female rats. This study included chemical analysis of Avocado and Flaxseed oils for its total phenols, total flavonoids and antioxidants capacity, the results illustrated that each 100ml of avocado and flaxseed oils contain 5.97±0.35mg and 28.99±0.60mg respectively as gallic acid equivalent (GAE) for total phenols and 0.20±0.03mg and 0.93±0.01 respectively as quercetin equivalent (QE) for total flavonoids as well as 50.58±2.39 µl and 95.74±4.73µl for total antioxidant capacity as Torolx equivalent (TE).
After chemical analysis of oils, its used for the biological trial: throughout this study sixty healthy female adult albino rats Wister strain weighing 150±10g were subjected to experimentation. The experiment divided to 2 sections; healthy and osteoporotic groups as follows; The first main group consists of ten rats served as normal healthy control. The second main group consists of fifty rats served as osteoporotic control. Rats were treated with 6mg prednisolone (As GC)/kg body weight daily by stomach tube for the first three weeks to induce osteoporosis; After that four rats were sacrificed and a dual x-ray absorptiometry (DEXA) had been done on right femur bone to insure osteoporosis induction. After osteoporosis induction, rats were subdivided into five subgroups, Subgroup (1) served as osteoporotic rats fed on balanced diet and subgroup (2) served as osteoporotic rats fed on normal diet and supplemented with calcium as Ca carbonate. Subgroup (3) served as osteoporotic rats fed on normal diet containing 4% avocado oil and supplemented with Ca carbonate. Subgroup (4) served as osteoporotic rats fed on normal diet containing 4% flaxseed oil and supplemented with Ca carbonate. Subgroup (5) served as osteoporotic rats fed on normal diet containing 4% mixture of avocado and flaxseed oils and supplemented with Ca carbonate. Diet freely was offered to all groups and water ad libitum for 6 weeks. The results illustrated that:
1- The biological measurements indicated that the GC induced osteoporotic rats caused significant reduction in final body weight and food intake (661.00 and 140.50g) by 24.11% and 13.24% compared to healthy rats. While osteoporotic groups fed on Ca supplement with avocado oil, Ca supplement with flaxseed oil or Ca supplement with oils mix daily had a significant increment in final body weight compared to osteoporotic control (171.88, 164.50, 170.88g) and food intake (732.88, 756.50, 761.88g) respectively. Moreover, Treatment of osteoporotic rats with Ca supplement with avocado oil had the highest FER by 134.78%, and osteoporotic rats fed on Ca supplement only had the lowest FER by 73.91% compared to osteoporotic group. Also osteoporotic rats fed on Ca supplement with flaxseed oil or Ca supplement with oils mix recorded increase in FER by 86.96% compared to osteoporotic rats.
2- The results from lipid profile analysis revealed that induction of osteoporosis caused a significant elevation in total cholesterol, triacylglycerol and low density lipoprotein cholesterol (LDL-C) levels (151.63 vs. 110.50mg/dl), (115.50 vs. 78.98mg/dl) and (44.80 vs. 66.17mg/dl), respectively compared to healthy control. While after feeding Ca supplement with avocado and/or flaxseed oils recorded a significant (p>0.05) decrement in their levels (110.25, 109.63, 106.22mg/dl) for total cholesterol, (62.03, 65.66, 64.07mg/dl) for triacylglycerol and (31.07, 29.89, 27.11mg/dl) for LDL-C, respectively, but feeding Ca supplement only has the least effect on decreasing their levels (131.25, 105.32, 47.81mg/dl) respectively compared to osteoporotic group. While feeding Ca supplement, Ca with either avocado or flaxseed oil, Ca supplement with oils mix caused a significant increment in high density lipoprotein cholesterol (HDL-C) level (64.81, 66.73, 66.59, 67.25mg/dl) respectively. But LDL-C/HDL-C ratio illustrated the more effective role of avocado and flaxseed oils other than feeding Ca supplement only even its high level of HDL-C, and this revealed the role of the synergistic effect of oils on Ca bioavailability.
3- The results of the current study showed that there was a significant decrement in blood reduced glutathione (GSH) level in osteoporotic group (10.80 vs. 23.05mg/dl) by 53.15% compared to normal control (p> 0.05). When osteoporotic rats fed on Ca supplement with avocado and/or flaxseed oils resulted in increment in its level by 36.89%, 66.39%, 80.93 %, respectively, while feeding Ca supplement only resulted the least improvement in antioxidant status by 31.39% compared to osteoporotic rats. Moreover, GC-induced osteoporosis caused a significant increment in serum malondialdehyde (MDA) and serum C-reactive protein (CRP) (12.13 vs. 3.40µmol/ml, 6.96 vs. 3.47mg/L), respectively compared to healthy group. While feeding Ca supplement with avocado and/or flaxseed oils caused decrement in their levels (3.93, 3.66, 3.83 µmol/ml) for MDA, (3.18, 3.47, 3.14mg/L) for CRP compared to osteoporotic control.
4- GC induced osteoporosis group showed a significant (p>0.05) reduction in serum Ca and P levels (9.84, 4.25mg/dl), compared to healthy group. But after feeding osteoporotic rats Ca supplement only, there was increment in the Ca and P levels (10.25, 7.37mg/dl) respectively compared to osteoporotic control. While, feeding osteoporotic rats Ca supplement with either avocado or flaxseed oil or Ca supplement with both oils showed significant increment in Ca level and their values were (10.53, 10.56, 10.55mg/dl), respectively and also significant increment in P level and their values were (7.28, 7.33, 8.04) compared to osteoporotic group (P<0.05). While comparing urine Ca and P levels of osteoporotic control with normal control, it was clear that the Ca and P levels of osteoporotic group increased by 40.34% and 42.90% respectively. But when feeding osteoporotic rats Ca supplement alone or Ca supplement with either avocado oil or flaxseed oils, or Ca supplement with oils mix, a marked decrease in Ca and P levels compared to osteoporotic control consuming balanced diet plus water only were recorded (52.62, 50.29, 33.34, 35.86mg/dl) for Ca and (59.26, 50.01, 50.59, 42.00mg/dl) for P respectively. While regard to results of bone Ca and P levels of osteoporotic rats which were (10.34 and 8.79 g%). It was observed that the treatment of osteoporotic rats by avocado and/or flaxseed oils led to a significant increment in Ca and P levels that were (19.53, 19.71, 19.90 g%) for Ca and (12.08, 12.05, 12.16 g%) for P, respectively compared to osteoporotic rats (P<0.05).
5- There was a significant increment in OC level and ALP activities in the osteoporotic rats (18.75 vs. 17.60 ng/ml and 87.77 vs. 54.02 IU/L) by 6.53% and 62.48% compared to the healthy control group (p>0.05). It was clear that after feeding osteoporotic groups avocado and/or flaxseed oils with Ca supplemented diet daily showed a significant decrement in OC level and ALP activity in osteoporotic rats. This decrement was (17.82ng/ml, 71.27 IU/L) for osteoporotic rats fed on avocado oil with Ca and was (17.69 ng/ml, 64.93 IU/L) for osteoporotic rats fed on flaxseed oil with Ca. While in cases of osteoporotic rats fed on Ca supplement with both oils, OC level and ALP activity showed the highest significant decrement in their values (17.19 ng/ml, 57.46 IU/L), but feeding Ca supplement only had less significant decrement (18.28ng/ml, 75.89IU/L) compared to osteoporotic control (p>0.05). Moreover, induction of osteoporosis caused a statistically (p> 0.05) significant decrement in estradiol E2 level which was (48.81 vs. 107.54 pg/ml) by 54.61% compared to healthy group. While feeding osteoporotic rats avocado and/or flaxseed oil with Ca supplemented diet recorded a significant increment by 88.51%, 108.38% and 69.90% respectively while, feeding osteoporotic rats Ca supplement only recorded the least significant (p>0.05) increment by 28.01% compared to osteoporotic control compared to osteoporotic control.
6- Results also are demonstrated that feeding diet containing Ca supplement with either avocado or flaxseed oil, Ca supplement with oils mix caused a statistically significant improvement in ACP activity and PTH level with significant (p>0.05) decrease (29.49, 28.99, 24.06 vs. 93.12 U/L) for ACP, (51.17, 52.33, 56.35 vs. 127.42 pg/ml) for PTH, respectively compared to osteoporotic control. While feeding Ca supplement only recorded the least significant decrement in ACP activity and PTH level (38.32 U/L and 60.94 pg/ml) respectively compared to osteoporotic group.
7- GC induced osteoporotic caused a significant decrement in weight, diameter and length of femur bone by (19.64%, 17.37% and 5.52%) compared to the healthy control which consuming only balanced diet plus water ad libitum (p<0.05). When osteoporotic rats fed on Ca supplement with avocado oil, Ca supplement with flaxseed oil or Ca supplement with oils mix recorded increment in weight of femur bone by (26.67%, 24.44% and 24.44%) and diameter of femur bone by (15.89%, 14.95% and 14.49%), and length of femur bone by (3.28%, 4.01% and 2.55%), respectively compared to osteoporotic control. While feeding Ca supplement only has less effect than oils by (15.56%, 8.88% and 0.73%) respectively compared to osteoporotic group.
8- The results of bone mineral density (BMD) and bone mineral content (BMC) illustrated long term used GC caused a significant decrement in BMD (0.096 vs. 0.132g/cm2) by 27.27%, and in BMC (0.13 vs. 0.29g) by 55.17% compared to healthy rats. But when the osteoporotic rats fed diet containing Ca supplement only, Ca supplement with avocado and/or flaxseed oil, a marked rise in the values of BMD and BMC were recorded, the values were (0.113, 0.137, 0.148, 0.151g/cm2) for BMD and (0.21, 0.33, 0.50, 0.56g) for BMC compared to osteoporotic group fed on balanced diet plus water only respectively (p> 0.05).
from the current result it could be concluded that both Avocado and Flaxseed oils have a good effect in improving bone turnover markers, oxidative and inflammatory status, and lipid profile that could modulate the severity of osteoporosis induced by GC. The best improvement was figured with using a mix of both oils.