Effect of sesamol on the pathophysiological changes induced by surgical menopause in rodents

Sesamol improves bone mass in ovary intact growing and adult rats but accelerates bone deterioration in the ovariectomized rats

Sesamol, an active component in sesame seeds, is known for its health benefits. However, its effect on bone metabolism remains unexplored. The present study aims to investigate the effect of sesamol on growing, adult and osteoporotic skeleton and its mechanism of action. Sesamol at various doses were administered orally to growing, ovariectomized, and ovary-intact rats. Alterations in bone parameters were examined using micro-CT and histological studies. Western blot and mRNA expression from long bones were performed. We further evaluated the effect of sesamol on osteoblast and osteoclast function and its mode of action in the cell culture system. These data showed that sesamol was able to promote peak bone mass in growing rats. However, sesamol had the opposite effect in ovariectomized rats, evident from gross deterioration of trabecular and cortical microarchitecture. Concurrently, it improved the bone mass in adult rats. In vitro results revealed that sesamol enhances the bone formation by stimulating osteoblast differentiation through MAPK, AKT, and BMP-2 signaling. In contrast, it enhances osteoclast differentiation and expression of osteoclast-specific genes in osteoclast differentiation medium. Interestingly, in presence of estrogen, the effect reversed and sesamol decreased osteoclast differentiation, in vitro. Sesamol improves bone microarchitecture in growing and ovary-intact rats, whereas it enhances the bone deterioration in ovariectomized rats. While sesamol promotes bone formation, its opposing effect on the skeleton can be attributed to its dual effect on osteoclastogenesis in presence and absence of estrogen. These findings in the preclinical context suggests a special attention towards the detrimental effect of sesamol in postmenopausal women.

Dietary supplementation for female infertility: Recent advances in the nutritional therapy for premature ovarian insufficiency

Premature ovarian insufficiency (POI) ranks top in the reproductive disorders that may impair multiple functioning systems, reduce the quality of life and ultimately deprive patients of their fertility among women. Symptoms can be partially alleviated by present hormone replacement therapy that cannot improve conception or decrease occurrence rates of systemic complication. Nutritional dietary supplements are attracting more and more attention because of their safety, bioavailability, and efficacy for well-being. Nutrients in the daily food are composed of carbohydrates, fat and lipoprotein, protein and polypeptide, vitamins, and vegetable or fruits containing phytoestrogens. These are functional nutrients due to the proliferative, anti-inflammatory, anti-oxidant, and mitochondria-protective potential during the course of menopause. Apart from dietary nutrients, microbe-related nutritional substances, including probiotics, prebiotics and the combination-synbiotics, display high potential as well in supporting estrous cycle, ovarian viability and modulating other vital reproductive functions. The present review will discuss dietary and microbial nutrients and their roles and applications in the living body based upon animal or human research, evaluate possible effect mechanisms from molecular, cellular and tissue levels, and provide insights into nutritional therapy for prolonging reproductive lifespan in female patients.

Sesamol protects the function and structure of rat ovaries against side effects of cyclophosphamide by decreasing oxidative stress and apoptosis

AIM

Chemotherapy with cyclophosphamide can damage ovaries and cause infertility in girls and women. Sesamol is a phenolic antioxidant that can protect various organs from damage. The purpose of this study was to evaluate the effects of sesamol on protecting the function and structure of rat ovaries against the side effects of a chemotherapy model with cyclophosphamide.

METHODS

Twenty-four adult female Wistar rats were randomly divided into three groups: (1) normal group, without any treatment, (2) control group, immediately after receiving cyclophosphamide, 0.5% dimethyl sulfoxide (DMSO) as the solvent of sesamol was intraperitoneally injected for 14 consecutive days, (3) sesamol group, immediately after receiving cyclophosphamide, 50 mg/kg sesamol was intraperitoneally injected for 14 consecutive days. Four weeks after the last injection, superoxide dismutase (SOD) activity and malondialdehyde (MDA) levels in the ovary, anti-Mullerian hormone (AMH) levels in the serum, number of ovarian follicles in different stages, and expression of proteins growth differentiation factor-9 (GDF-9), Bcl-2, and Bax in the ovary were evaluated.

RESULTS

The results of SOD activity and MDA levels in the ovary, AMH levels in the serum, number of ovarian follicles in different stages, and expression of proteins GDF9, Bcl-2, and Bax in the ovary were significantly more favorable in the sesamol group than the control group.

CONCLUSIONS

The results suggest that sesamol may protect function and structure in the rat ovaries against side effects of the chemotherapy model with cyclophosphamide by decreasing oxidative stress and apoptosis in the ovary.

Selective ER-β agonists alleviate neuronal deficits in insulin-resistant estrogen-deficient rats

OBJECTIVE

The present study aimed to determine the effect of estrogen receptor (ER) agonists on depression and memory impairment in insulin-resistant ovariectomized (OVX) rats.

METHODS

Rats underwent bilateral ovariectomy, and low-dose streptozotocin (STZ) and a high-fat diet (58% fat, 25% protein, and 17% carbohydrates as a percentage of kilocalories) were administered to induce an estrogen-deficient insulin-resistant state. After 1 week of STZ administration, rats were treated with 17β-estradiol (17βE2) and selective ER-α (propylpyrazoletriol) and ER-β (diarylpropionitrile) agonists (10 μg/kg subcutaneously). Memory was evaluated using the Morris water maze and depression using the forced swim test.

RESULTS

Treatment with selective ER-β agonist and 17βE2 but not with selective ER-α agonist significantly modulated the neurobehavioral deficits in insulin-resistant OVX rats. These neurobehavioral parameters were further correlated with brain-derived neurotrophic factor (BDNF) levels and acetylcholinesterase (AChE) activity. Selective ER-β agonist and 17βE2 significantly modulated BDNF levels and AChE activity in insulin-resistant OVX rats. Significant increases in estradiol and uterine weight were observed in 17βE2-treated rats, but selective ER agonists did not show any effect.

CONCLUSION

ER-β agonist can be an effective strategy for the mitigation of memory loss and depression in an estrogen-deficient insulin-resistant state without all of the deleterious feminizing effects that occur with the use of 17βE2.

Lignans of Sesame (Sesamum indicum L.): A Comprehensive Review

Major lignans of sesame sesamin and sesamolin are benzodioxol--substituted furofurans. Sesamol, sesaminol, its epimers, and episesamin are transformation products found in processed products. Synthetic routes to all lignans are known but only sesamol is synthesized industrially. Biosynthesis of furofuran lignans begins with the dimerization of coniferyl alcohol, followed by the formation of dioxoles, oxidation, and glycosylation. Most genes of the lignan pathway in sesame have been identified but the inheritance of lignan content is poorly understood. Health-promoting properties make lignans attractive components of functional food. Lignans enhance the efficiency of insecticides and possess antifeedant activity, but their biological function in plants remains hypothetical. In this work, extensive literature including historical texts is reviewed, controversial issues are critically examined, and errors perpetuated in literature are corrected. The following aspects are covered: chemical properties and transformations of lignans; analysis, purification, and total synthesis; occurrence in Seseamum indicum and related plants; biosynthesis and genetics; biological activities; health-promoting properties; and biological functions. Finally, the improvement of lignan content in sesame seeds by breeding and biotechnology and the potential of hairy roots for manufacturing lignans in vitro are outlined.

Total Polysaccharides of Lily Bulb Ameliorate Menopause-Like Behavior in Ovariectomized Mice: Multiple Mechanisms Distinct from Estrogen Therapy

Our previous study has demonstrated the effects of aqueous extract of lily bulb in alleviating menopause-related psychiatric symptoms in ovariectomized (OVX) mice. This study sought to further investigate the psychotropic effects of total polysaccharides of lily bulb (TPLB) against anxiety, depression, and cognitive deterioration and the underlying mechanisms in OVX mice using behavioral, neurochemical, molecular, and proteomic approaches in comparison with estrogen therapy. While TPLB and estradiol showed similar effects in reducing OVX-induced anxiety, depression, and cognitive impairment, the psychotropic effects of TPLB were more closely associated with the predominant activation of estrogen receptors (ERs) and regulation of brain regional neurotransmitters and neurotrophins with minor effects on the uterus. Estradiol had similar potencies in binding affinity at ERα and ERβ, which caused widespread genetic and epigenetic effects. In contrast, TPLB displayed a higher affinity at ERβ than ERα, triggering the specific Ras/Akt/ERK/CREB signaling pathway without affecting any epigenetic activity. TPLB additionally modulated multiple proteins associated with mitochondrial oxidative stress, but estradiol did not. These results indicate that TPLB has comparable efficacy in reducing menopause-associated neuropsychological symptoms with a better safety profile compared to estrogen therapy. We suggest that TPLB could serve as a novel agent for menopause syndrome.

Combined Effects of Rosuvastatin and Exercise on Gene Expression of Key Molecules Involved in Cholesterol Metabolism in Ovariectomized Rats

The purpose of this study was to investigate the effects of three weeks of rosuvastatin (Ros) treatment alone and in combination with voluntary training (Tr) on expression of genes involved in cholesterol metabolism (LDLR, PCSK9, LRP-1, SREBP-2, IDOL, ACAT-2 and HMGCR) in the liver of eight week-old ovariectomized (Ovx) rats. Sprague Dawley rats were Ovx or sham-operated (Sham) and kept sedentary for 8 weeks under a standard diet. Thereafter, rats were transferred for three weeks in running wheel cages for Tr or kept sedentary (Sed) with or without Ros treatment (5mg/kg/day). Six groups were formed: Sham-Sed treated with saline (Sal) or Ros (Sham-Sed-Sal; Sham-Sed-Ros), Ovx-Sed treated with Sal or Ros (Ovx-Sed-Sal; Ovx-Sed-Ros), Ovx trained treated with Sal or Ros (Ovx-Tr-Sal; Ovx-Tr-Ros). Ovx-Sed-Sal rats depicted higher (P < 0.05) body weight, plasma total cholesterol (TC) and LDL-C, and liver TC content compared to Sham-Sed-Sal rats. In contrast, mRNA levels of liver PCSK9, LDLR, LRP-1 as well as plasma PCSK9 concentrations and protein levels of LRP-1 were reduced (P < 0.01) in Ovx-Sed-Sal compared to Sham-Sed-Sal rats. However, protein levels of LDLR increased (P < 0.05) in Ovx-Sed-Sal compared to Sham-Sed-Sal rats. Treatment of Ovx rats with Ros increased (P < 0.05) mRNA and protein levels of LRP-1 and PCSK9 but not mRNA levels of LDLR, while its protein abundance was reduced at the level of Sham rats. As a result, plasma LDL-C was not reduced. Exercise alone did not affect the expression of any of these markers in Ovx rats. Overall, Ros treatment corrected Ovx-induced decrease in gene expression of markers of cholesterol metabolism in liver of Ovx rats, but without reducing plasma LDL-C concentrations. Increased plasma PCSK9 levels could be responsible for the reduction of liver LDLR protein abundance and the absence of reduction of plasma LDL-C after Ros treatment.

Hepatoprotective effects of sesamol loaded solid lipid nanoparticles in carbon tetrachloride induced sub-chronic hepatotoxicity in rats

Sesamol is a phenolic component of sesame seed oil, which has been established as an antioxidant and also possesses potential for hepatoprotection. However, its protective role in carbon tetrachloride (CCl4 ) induced sub-chronic hepatotoxicity has not been studied. Limited oral bioavailability (BA) and rapid elimination (as conjugates) in rats is reported for sesamol. Considering its significant antioxidant potential and compromised BA, we packaged sesamol into solid lipid nanoparticles (S-SLNs) to enhance its hepatoprotective bioactivity. S-SLNs prepared by microemulsification method were nearly spherical in shape with an average particle size of 120.30 nm and their oral administration at 8 mg/kg body weight (BW) showed significantly (p < 0.001) better hepatoprotection than free sesamol (FS) and a well established hepatoprotective antioxidant silymarin [SILY (25 mg/kg BW); p < 0.05) in CCl4 induced sub-chronic liver injury in rats. Evaluations were done in terms of histological changes in the liver tissue, liver injury markers (serum alanine aminotransferase, serum aspartate aminotransferase, and serum lactate dehydrogenase); oxidative stress markers (lipid peroxidation, superoxide dismutase, and reduced glutathione) and proinflammatory response marker (tumor necrosis factor-alpha).

High dietary cholesterol and ovariectomy in rats repress gene expression of key markers of VLDL and bile acid metabolism in liver

BACKGROUND

The purpose of the study was to evaluate the effects of high dietary cholesterol in ovariectomized (Ovx) rats on several key markers of hepatic cholesterol and bile acid metabolism.

METHOD

Ovx and sham operated (Sham) rats were given either a standard diet (SD), a SD diet supplemented with 0.25% cholesterol (SD + Chol), or a high fat diet supplemented with 0.25% cholesterol (HF + Chol) for 5 weeks.

RESULTS

Ovx was associated with higher (P < 0.05) liver total cholesterol (TC) under the SD and the SD + Chol diet, while liver triglyceride (TG) content was higher in Ovx than in Sham rats in all 3 diet conditions. Surprisingly, the SD + Chol diet was associated with lower (P < 0.001) plasma TC and TG levels in Ovx than in Sham rats, suggesting a decrease in VLDL secretion. Accordingly, several transcripts of key markers of VLDL synthesis including microsomal TG transfer protein (Mttp) and Apob-100 were decreased (P < 0.05) in Ovx compared to Sham rats under the three dietary conditions and even more so for Mttp and Apob-100 when rats were fed the SD + Chol diet. Transcripts of bile acid transporters including bile salt export pump (Bsep) and Na + -taurocholate cotransporting polypeptide (Ntcp) were decreased by the addition of cholesterol to the SD diet in both Ovx and Sham rats.

CONCLUSION

These results indicate that a high cholesterol feeding and ovariectomy combine to reduce the gene expression of key markers of VLDL synthesis suggesting a reduction in excretion of cholesterol from the liver.

17α-Estradiol: a candidate neuroserm and non-feminizing estrogen for postmenopausal neuronal complications

Extensive evidence suggests that decline in ovarian function with menopause is associated with neuronal dysfunction. Major cause of this is rise in oxidative stress and inflammatory cytokines because of estrogen deficiency. 17β-Estradiol (E2, hormone with potent antioxidant and anti-inflammatory activity) has profound protective actions on multiple organ systems, but feminizing side effects of β-estradiol limits its clinical efficacy. 17α-Estradiol (E2α), a non feminizing congener, gives a ray of hope to the scientific community as an alternative strategy to treat menopause associated neuronal pathologies. We assessed the protective actions of 17α-estradiol (5, 10μg/kg) against cognitive deficits, depression and motor coordination after 4weeks of ovariectomy in rats and compared its efficacy with E2 at same doses. After the behavioral assay animals were sacrificed and their brains were harvested for biochemical studies. Uterine weights were also assessed. E2 and E2α (5, 10μg/kg) were equally protective against attenuating cognitive deficits, depressive symptoms and motor incoordination in OVX rats. Both demonstrated significant antioxidant activity and E2, but not E2α, increased serum estradiol levels and proliferated uterine weights, markers of feminizing action. It can thus be concluded that E2α offers safe alternative to E2 in protecting against menopausal neuropathologies.