Sesame oil supplementation: a potential breakthrough in postmenopausal osteoporosis prevention?

By Pooja Toshniwal PahariaJan 7 2024Reviewed by Sophia Coveney

In a recent study published in Scientific Reports, researchers evaluated the effects of daily sesame oil supplementation on postmenopausal osteoporosis in rats.

Background

Estrogen shortages cause postmenopausal osteoporosis in older women, a bone condition characterized by reduced bone mineral density (BMD) that has a negative influence on their life quality.

Millions of individuals suffer from the condition, which increases fragility fracture risk. Hormone replacement treatment (HRT) is a popular osteoporosis treatment; however, it can cause irregular vaginal bleeding and breast malignancy.

Thus, more effective and safer treatments are required. Sesame oil includes antioxidants, lignans, and fatty acids and has demonstrated sex hormone-altering effects in previous studies. Although prior research found osteoprotective benefits in ovariectomy (OVX) mice, the precise mechanisms underlying the impact of the oil on osteoporosis among postmenopausal women remain unknown.

About the study

The researchers of the present study investigated the potential processes behind daily sesame oil supplementation in the ovariectomized postmenopausal osteoporosis rat model.

The study involved 12-week-old female Sprague-Dawley rats who underwent bilateral OVX surgery. The team divided the animals into the following groups: Sham, OVX, SOL, and SOH. The sham group received a sham operation, the OVX group received OVX, the SOL group received 0.3 mL/kg per day orally, and the SOH group received 0.50 mL/kg per day of the oil orally for four months.

The researchers euthanized the rats using carbon dioxide (CO₂) inhalation following the experiments. They obtained rat blood samples for serological analysis. They assessed BMD and levels of osteocalcin, collagen cross-linked N-telopeptide (NTx), procollagen-I C-terminal propeptide (PICP), estradiol, and aromatase in the sera using enzyme-linked immunosorbent assays (ELISA).

The researchers performed histological examinations of the trabecular areas to confirm sesame oil osteoprotection in ovariectomized rats. In addition, they evaluated sesame oil’s impact based on serum alkaline phosphatase (ALP), osteocalcin levels, BMD, bone formation and resorption, PICP, and NTx levels.

Furthermore, the researchers investigated the impact of sexual hormones in osteoporosis prevention with sesame oil based on estradiol levels in the ovariectomized rat sera. Lastly, they explored the potential mechanisms underlying the effects of the oil on estradiol levels in serum.

Results

The researchers found that daily sesame oil supplementation significantly increased BMD, serum osteocalcin, and trabecular areas in ovariectomized rats. Sesame oil also elevated serum PICP levels and decreased NTx levels in these rats. Moreover, it effectively maintained serum estradiol and aromatase levels in OVX-induced osteoporotic rats.

The histological examination showed a significant reduction in trabecular areas in ovariectomized rats in comparison to sham rats. However, trabeculae increased in the high- and low-dose sesame oil groups. Total BMD was significantly lower in ovariectomized rats. The oil significantly elevated total BMD levels in the high- and low-dose sesame oil group rats in comparison to OVX rats.

In OVX group rats, serum ALP and osteocalcin levels were higher than in the sham rats. However, the SOH and SOL group rats showed significant reductions in these levels in comparison to OVX rats. In OVX rats, serological levels of estradiol were lower than in the sham rats, and the oil significantly increased serological estradiol in the SOH and SOL groups.

Sesame oil, rich in phytoestrogenic compounds like isoflavones, has been found to elevate serological estradiol in ovariectomized rats, offering an alternate treatment to estrogen replacement due to its reduced side effects.

Genistein aglycone can decrease the receptor activator of nuclear factor kappa beta (RANKL)/osteoprotegerin (OPG) ratio among ovariectomized rats and positively affect bone mineral density among osteopenic postmenopausal women.

Sesame seeds possess anti-inflammatory, osteoprotective, and oxidative stress-lowering effects while maintaining serum estradiol in osteoporotic rats. The phosphoinositide 3-kinase/protein kinase A (PI3K/PKA) and mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK2) signaling pathways mediate the protective effects of sesame oil in non-pregnant female rats.

Conclusions

The study findings showed that regular sesame oil supplementation can prevent osteoporosis in ovariectomized rats. The oil boosted bone formation, reduced bone resorption indicators, and elevated serum aromatase and estradiol levels, indicating that higher aromatase levels may be a method for maintaining serum estrogen in rats administered sesame oil.

Sesame oil lowered serum alkaline phosphatase levels while raising osteocalcin and total bone mineral density in OVX rats.

Sesame oil also boosted blood PICP levels while decreasing NTx levels, indicating that it may aid in maintaining bone turnover. These findings suggest a strong treatment potential for postmenopausal osteoporosis prevention. However, further study is needed to determine the impact of the oil in elevating BMD through the RANKL/RANK/OPG signaling pathway.