Incorporation of β-sitosterol into mitochondrial membrane enhances mitochondrial function by promoting inner mitochondrial membrane fluidity

Estrogen receptors in mitochondrial metabolism: age-related changes and implications for pregnancy complications

Estrogen hormones are primarily associated with their role as female sex hormones responsible for primary and secondary sexual development. Estrogen receptors are known to undergo age-dependent decreases due to age-related changes in hormone production. In the mitochondria, estrogen functions by reducing the production of reactive oxygen species in the electron transport chain, inhibiting apoptosis, and regulating mitochondrial DNA content. Moreover, estrogen receptors may be the key components in maintaining mitochondrial membrane potential and structure. Although estrogen plays a crucial role in the development of pregnancy, our understanding of how estrogen receptors change with aging during pregnancy remains limited. During pregnancy, estrogen levels are significantly elevated, with a corresponding upregulation of estrogen receptors, which play various roles in pregnancy. However, the exact role of estrogen receptors in pregnancy complications remains to be further investigated. The paper reviews the role of estrogen receptors in the regulation of mitochondrial metabolism and in pregnancy complications, with a special focus on the effect of age-related changes on estrogen levels and estrogen receptors function. We also address how estrogen maintains mitochondrial function, including reducing the production of reactive oxygen species in the electron transport chain, inhibiting apoptosis, regulating mitochondrial DNA content, and maintaining mitochondrial membrane potential and structure. However, the effects of estrogen on mitochondria-endoplasmic reticulum contacts have not been well studied. Based on these emergent roles in mitochondria, the differential roles of estrogen receptors in pregnancy complications are of great relevance. The paper emphasizes the association between maternal health and estrogen receptors and indicates the need for future research to elucidate the interdependence of estrogen receptor-regulated maternal health with mitochondrial function and their relationship with the gut microbiome. Overall, we summarize the important role of estrogen receptors during pregnancy and highlight the need for further research to better understand the role of estrogen receptors in aging and pregnancy complications. This not only helps to reveal the mechanism underlying the role of estrogen in maternal health but also has potential clinical implications for the development of new therapies targeting age-related diseases and pregnancy complications.

Elucidation of the inhibitory effects of Jiedu Yizhi formula on neuronal apoptosis in the treatment of Alzheimer's disease based on network pharmacology and in vivo experiments

OBJECTIVE

This study aimed to investigate the mechanism of action of Jiedu Yizhi formula (JDYZF) in the treatment of Alzheimer's disease (AD) through network pharmacology, molecular docking technology, and in vivo experiments.

METHOD

 The main active ingredients of seven herbs in the Chinese Medicine compound JDYZF were identified by searching the TCMSP database, PubChem database, CNKI, and other sources. Disease targets of AD were obtained from databases such as OMIM, TDD, DisGeNET, and DrugBank. A protein‒protein interaction (PPI) network was constructed using the STRING platform, and core targets were identified through topological analysis using Cytoscape software. Gene Ontology (GO) functional analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis of the relevant targets were performed using the Metascape database. The main active ingredients of JDYZF and potential core targets were identified based on degree values. Molecular docking technology was used to verify the interactions between the main active ingredients and potential core targets. Furthermore, water maze tests and hematoxylin-eosin (HE) staining of brain and liver tissues were performed to evaluate the effects of JDYZF on cognitive dysfunction in AD mice and neuronal damage in hippocampal brain tissue and to assess drug toxicity. PCR was performed to determine the expression levels of the apoptosis-related genes Bcl-2, Bax, and caspase-3 and to investigate the effect of JDYZF on hippocampal apoptosis in AD mice. Results. One hundred twelve core PPI target proteins, including CASP3, TP53, and VEGFA, were found between JDYZF and AD. The KEGG pathway enrichment analysis showed significant enrichment of the MAPK signaling pathway, PI3K/AKT signaling pathway and so on. Water maze tests revealed that the high-dose JDYZF treatment significantly improved the escape latency of AD model mice. The HE staining results showed that JDYZF exerted a protective effect on neuronal damage in the hippocampus of AD mice. JDYZF could upregulate the expression of the anti-apoptotic factor Bcl-2 while downregulating the expression of the proapoptotic factors Bax and caspase-3. Conclusion. JDYZF can improve the cognitive function of AD mice by suppressing cell apoptosis.

Effects of β-sitosterol on anxiety in migraine-induced rats: The role of oxidative/nitrosative stress and mitochondrial function

AIMS

Anxiety often coexists with migraine, and both conditions share a commonality in oxidative/nitrosative stress and mitochondrial dysfunction contributing to their pathogenesis. β-Sitosterol, a plant sterol, has shown promise in mitigating oxidative/nitrosative stress, enhancing mitochondrial function, and exerting neuroprotective effects. In this study, we investigated the impact of β-sitosterol on migraine-associated anxiety and whether this effect was associated with alleviation of oxidative/nitrosative stress and improvement in mitochondrial function.

METHODS

Nitroglycerin was used to induce migraine in adult male Wistar rats. β-Sitosterol treatment consisted of daily intraperitoneal injections (10 mg/kg) for 10 days following migraine induction. Anxiety levels were evaluated using open-field test (OFT) and hole-board test (HBT). Frontal cortex samples were analyzed for malondialdehyde (MDA), glutathione (GSH), reactive oxygen/nitrogen species, nitric oxide (NO) (markers of oxidative/nitrosative stress), and ATP (indicator of mitochondrial function).

RESULTS

Migraine induction led to impaired performance in both the OFT and the HBT. Concurrently, it elevated MDA, reactive oxygen/nitrogen species, and NO levels while diminishing GSH levels in the frontal cortex, signifying heightened oxidative/nitrosative stress. Moreover, ATP levels decreased, indicating mitochondrial dysfunction. Treatment with β-sitosterol significantly restored performance in both behavioral assays and normalized the levels of MDA, GSH, reactive oxygen/nitrogen species, NO, and ATP.

CONCLUSION

β-Sitosterol exerted anxiolytic effects in migraine, which can be attributed to its ability to ameliorate oxidative/nitrosative stress and enhance mitochondrial function.

Bioactive Compounds in Citrus reticulata Peel Are Potential Candidates for Alleviating Physical Fatigue through a Triad Approach of Network Pharmacology, Molecular Docking, and Molecular Dynamics Modeling

Physical fatigue (peripheral fatigue), which affects a considerable portion of the world population, is a decline in the ability of muscle fibers to contract effectively due to alterations in the regulatory processes of muscle action potentials. However, it lacks an efficacious therapeutic intervention. The present study explored bioactive compounds and the mechanism of action of Citrus reticulata peel (CR-P) in treating physical fatigue by utilizing network pharmacology (NP), molecular docking, and simulation-based molecular dynamics (MD). The bioactive ingredients of CR-P and prospective targets of CR-P and physical fatigue were obtained from various databases. A PPI network was generated by the STRING database, while the key overlapping targets were analyzed for enrichment by adopting KEGG and GO. The binding affinities of bioactive ingredients to the hub targets were determined by molecular docking. The results were further validated by MD simulation. Five bioactive compounds were screened, and 56 key overlapping targets were identified for CR-P and physical fatigue, whereas the hub targets with a greater degree in the PPI network were AKT1, TP53, STAT3, MTOR, KRAS, HRAS, JAK2, IL6, EGFR, and ESR1. The findings of the enrichment analysis indicated significant enrichment of the targets in three key signaling pathways, namely PI3K-AKT, MAPK, and JAK-STAT. The molecular docking and MD simulation results revealed that the bioactive compounds of CR-P exhibit a stronger affinity for interacting with the hub targets. The present work suggests that bioactive compounds of CR-P, specifically Hesperetin and Sitosterol, may ameliorate physical fatigue via the PI3K-AKT signaling pathway by targeting AKT1, KRAS, and MTOR proteins.

Neuroprotective Effect of Zishen Huoxue Decoction treatment on Vascular Dementia by activating PINK1/Parkin mediated Mitophagy in the Hippocampal CA1 Region

ETHNOPHARMACOLOGICAL RELEVANCE

Zishen Huoxue Decoction (ZSHXD) is a Traditional Chinese Medicine (TCM) prescription for the treatment of vascular dementia (VD). Although the clinical effects of ZSHXD have been demonstrated, the molecular mechanisms underlying the neuroprotective effects of ZSHXD remain unclear.

AIM OF THE STUDY

To explore whether the neuroprotective effect of Zishen Huoxue Decoction (ZSHXD) treatment is associated with the PINK1/Parkin pathway-mediated mitophagy in hippocampal CA1 region of 2-VO model rats.

MATERIALS AND METHODS

Seventy-two male SD rats were randomly divided into the sham group, model group, Donepezil (0.45 mg/kg) group, ZSHXD low dose group (8.9 g/kg), ZSHXD medium dose group (17.8 g/kg), and ZSHXD high dose group (35.6 g/kg). Two-vessel occlusion (2-VO) rat model is established to evaluate the therapeutic effect of ZSHXD pretreatment. Hematoxylin-eosin (HE) staining is conducted to detect the morphological changes of neurons and the number of normal neurons in the hippocampal CA1 region. Then, the mitochondrial function and structure were reflected by the mitochondrial membrane potential (MMP) levels and transmission electron microscopy (TEM). Meanwhile, the expression of mitophagy related proteins mediated by PINK1/Parkin was detected by western blot (WB). After that, malondialdehyde (MDA) and superoxide dismutase (SOD) levels were measured by Elisa. At last, the apoptosis-related proteins Caspase-3、Bax、Bcl-2 were measured by WB.

RESULTS

The results depict that ZSHXD has dose-dependently improved the cognitive function in 2-VO model rats. It has also been showed that ZSHXD can alleviate neuron damage, rescue the mitochondrial structural injury and dysfunction in hippocampal CA1 region. Besides, ZSHXD has increased the activity of SOD and decreased the activity of MDA. In addition, ZSHXD can inhibit apoptosis with Caspase-3, Bax decreasing and Bcl-2 increasing. Specially, the protection of ZSHXD showed in 2-VO model rats is along with the upregulation of PINK1, Parkin and LC3-Ⅱ/Ⅰ, and downregulation of p62 in the hippocampal CA1 region.

CONCLUSIONS

This study reveals that ZSHXD protects the 2-VO model rats from ischemic injury by activating the PINK1/Parkin-mediated mitophagy in the hippocampal CA1 region.

Qi Fu Yin ameliorates neuroinflammation through inhibiting RAGE and TLR4/NF-κB pathway in AD model rats

The purpose of this study is to investigate the therapeutic effect of Qi Fu Yin (QFY) on Alzheimer's disease (AD) both computationally and experimentally. Network pharmacology analysis and molecular docking were conducted to identify potential targets and signaling pathways involved in QFY treating AD. Streptozotocin-induced AD rat model was used to verify important targets and predicted pathways. The components of QFY were identified using liquid chromatography-tandem mass spectrometry. The results indicate that the potential targets of QFY are highly enriched for anti-inflammatory pathways. Molecular docking analysis revealed stable structures formed between QFY's active compounds, including stigmasterol, β-sitosterol, and isorhamnetin, and the identified targets. In vivo, QFY improved cognitive memory in AD rats and reduced the mRNA expression levels of toll-like receptor 4 (TLR4), the receptor for advanced glycation end products (AGER), and the inflammatory factors interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) in the brains of AD rats. Furthermore, QFY effectively reduced nuclear translocation of nuclear factor-kappa B (NF-κB) and inhibited NF-κB and microglia activation. In conclusion, QFY can ameliorate neuroinflammation in AD model rats, partly via the inhibition of TLR4 and RAGE/NF-κB pathway and microglia activation, thereby enhancing learning and memory in AD model rats.

Mairá-Potato (Casimirella sp.): Botanical, Food, Pharmacological, and Phytochemical Aspects

Millions of people in the world live in food insecurity, so identifying a tuber with characteristics capable of meeting the demand for food and also identifying active compounds that can be used to minimize harm to human health is of great value. The aim was to carry out a review based on systematic review tools and the main objective was to seek information on botanical, food, pharmacological, and phytochemical aspects of Casimirella sp. and propose possible applications. This review showed papers that addressed botanical, food, pharmacological, and phytochemical aspects of the Mairá-potato and presented suggestions for using this tuber allied to the information described in the works found in the Google Academic, Scielo, Science Direct, Scopus, PubMed, and Web of Science databases. This review synthesized knowledge about the Mairá-potato that can contribute to the direction of further research on the suggested technological applications, both on the use of this tuber as a polymeric material and its use as biomaterial, encapsulation, bioactive use, and 3D printing, because this work collected information about this non-conventional food plant (PANC) that shows great potential for use in various areas of study.

De novo phytosterol synthesis in animals

Sterols are vital for nearly all eukaryotes. Their distribution differs in plants and animals, with phytosterols commonly found in plants whereas most animals are dominated by cholesterol. We show that sitosterol, a common sterol of plants, is the most abundant sterol in gutless marine annelids. Using multiomics, metabolite imaging, heterologous gene expression, and enzyme assays, we show that these animals synthesize sitosterol de novo using a noncanonical C-24 sterol methyltransferase (C24-SMT). This enzyme is essential for sitosterol synthesis in plants, but not known from most bilaterian animals. Our phylogenetic analyses revealed that C24-SMTs are present in representatives of at least five animal phyla, indicating that the synthesis of sterols common to plants is more widespread in animals than currently known.

β-Sitosterol & quercetin enhances brain development in iodine deficient rat models

BACKGROUND

Recently thyroid hormone studies on brain growth, development and activity are regaining popularity. Thyroid hormones have long been believed to play critical role in mammalian brain growth and maturation regulating facets of neuronal cell growth, proliferation and differentiation and further signaling and glial cell differentiation. Deficiency of these hormones in mother leads to mental retardation in the subsequent offspring's.

METHODS

In this presented study, brain development of iodine deficient rat models created through deficiency in feeding, mating and further selection. Young adult female wistar rats were induced with iodine deficiency and then mated with healthy male rats. These pregnant hypothyroid induced females were treated with β-sitosterol (150 mg/kg/day) and quercetin (150 mg/kg/day) alone and in combination for whole gestation period. Analysis were dealt with the genetic and histological studies of the pups brain. PCR based RNA analysis was also carried out. Histology was done using eosin and hematoxylin.

RESULTS

Positive impacts of the β-sitosterol and quercetin on the iodine deficient brain were observed upon histological and PCR analysis. Altogether, the analysis proves that combined doses of β-sitosterol and quercetin for normal brain development in iodine deficient infants hence can be potentially applied as therapeutics in iodine deficiency circumstances.

Robustness of the Krebs Cycle under Physiological Conditions and in Cancer: New Clues for Evaluating Metabolism-Modifying Drug Therapies

The Krebs cycle in cells that contain mitochondria is necessary for both energy production and anabolic processes. In given cell/condition, the Krebs cycle is dynamic but remains at a steady state. In this article, we first aimed at comparing the properties of a closed cycle versus the same metabolism in a linear array. The main finding is that, unlike a linear metabolism, the closed cycle can reach a steady state (SS) regardless of the nature and magnitude of the disturbance. When the cycle is modeled with input and output reactions, the “open” cycle is robust and reaches a steady state but with exceptions that lead to sustained accumulation of intermediate metabolites, i.e., conditions at which no SS can be achieved. The modeling of the cycle in cancer, trying to obtain marked reductions in flux, shows that these reductions are limited and therefore the Warburg effect is moderate at most. In general, our results of modeling the cycle in different conditions and looking for the achievement, or not, of SS, suggest that the cycle may have a regulation, not yet discovered, to go from an open cycle to a closed one. Said regulation could allow for reaching the steady state, thus avoiding the unwanted effects derived from the aberrant accumulation of metabolites in the mitochondria. The information in this paper might be useful to evaluate metabolism-modifying medicines.

Phytosterols: Potential Metabolic Modulators in Neurodegenerative Diseases

Phytosterols constitute a class of natural products that are an important component of diet and have vast applications in foods, cosmetics, and herbal medicines. With many and diverse isolated structures in nature, they exhibit a broad range of biological and pharmacological activities. Among over 200 types of phytosterols, stigmasterol and β-sitosterol were ubiquitous in many plant species, exhibiting important aspects of activities related to neurodegenerative diseases. Hence, this mini-review presented an overview of the reported studies on selected phytosterols related to neurodegenerative diseases. It covered the major phytosterols based on biosynthetic considerations, including other phytosterols with significant in vitro and in vivo biological activities.

The dopaminergic neuroprotective effects of different phytosterols identified in rice bran and rice bran oil

Phytosterols are important bioactive compounds in rice bran and rice bran oil, and the compositions of different phytosterols in rice bran and rice bran oil were investigated in our previous research. In this study, the dopaminergic neuroprotective effects and the underlying mechanisms of sitosterol, cycloartenyl ferulate, 24-methylenecycloartanyl ferulate and campesteryl ferulate identified in rice bran and rice bran oil were investigated in a rotenone-treated C. elegans model. The results indicated that the increased oxidative stress resistance induced by the activation of the DAF-16/FOXO pathway and the inhibition of the apoptotic protein CED-3 overexpression might play an important role in protecting the dopaminergic neurons. The results of this research reveal a new bioactivity of different phytosterols and are helpful for the further nutritional evaluation of rice bran and rice bran oil.

The Use of Chinese Yang/Qi-Invigorating Tonic Botanical Drugs/Herbal Formulations in Ameliorating Chronic Kidney Disease by Enhancing Mitochondrial Function

Background: Chronic kidney disease (CKD) is a leading cause of morbidity and mortality. Mitochondrial dysfunction has been implicated as a key factor in the development of CKD. According to traditional Chinese medicine (TCM) theory, many Chinese Yang/Qi-invigorating botanical drugs/herbal formulations have been shown to produce promising outcomes in the clinical management of CKD. Experimental studies have indicated that the health-promoting action of Yang/Qi invigoration in TCM is related to the up-regulation of mitochondrial energy generation and antioxidant status. Objective: In this review, we aim to test whether Chinese Yang/Qi-invigorating tonic botanical drugs/herbal formulations can provide medical benefits in CKD and its complications. And we also explore the possible involvement of mitochondrial-associated signaling pathway underlying the beneficial effects of Yang/Qi invigoration in TCM. Methods: A systematic search of "PubMed", "China National Knowledge Infrastructure (CNKI)" and "Google Scholar" was carried out to collect all the available articles in English or Chinese related to Chinese Yang/Qi-invigorating tonic botanical drugs/herbal formulations and their effects on mitochondrial function and chronic kidney disease. Result and Discussion: The relationship between the progression of CKD and mitochondrial function is discussed. The effects of Chinese Yang/Qi-invigorating tonic botanical drugs/herbal formulations and their active ingredients, including phytosterols/triterpenes, flavonoids, and dibenzocyclooctadiene lignans, on CKD and related alterations in mitochondrial signaling pathways are also presented in this review. In the future, exploration of the possible beneficial effects and clinical studies of more Yang- and Qi-invigorating botanical drugs/herbal formulations in the prevention and/or/treatment of CKD and the molecular mechanisms relating to the enhancement of mitochondrial functions warrants further investigation. Conclusion: Given the critical role of mitochondrial function in safeguarding renal functional integrity, the enhancement of mitochondrial energy metabolism and antioxidant status in kidney tissue is likely involved in renal protection. Future studies on the biochemical and chemical basis underlying the effects of Chinese Yang/Qi-invigorating tonic botanical drugs/herbal formulations from a mitochondrial perspective will hopefully provide novel insights into the rational development of new drugs for the prevention and/or treatment of CKD.

New insights into molecular mechanisms of "Cold or Hot" nature of food: When East meets West

Traditional Chinese medicines are largely adopted in China and have a key importance in the world medical system. Cold-hot nature is the important characteristics of food and Chinese Materia Medica in the traditional Chinese medicine, relating to food functions in the organism. As compared to the studies on the cold and hot nature in Chinese medicine, the research studies carried out to establish the association between cold-hot nature and food are insufficient. Intending to investigate the criteria to discriminate the cold-hot nature of food and Chinese medicine scientifically, this review collected the cold-hot nature-related literature in recent 20 years in several popular databases such as PubMed, Google Scholar, and Science Direct. This review explored that the cold and hot natures are not only linked to the chemical components such as water, carbohydrates, lipids, and amino acids, but also correlated to the biological effects, comprising of energy metabolism, inflammation response, oxidation reaction, immune response, and cell growth and proliferation. Besides, this review further put forward the possibility that cold-hot nature of food and Chinese medicine exert different biological effects on the inflammatory response via regulating the signaling pathways viz. NF-κB and MAPK. More extensive studies are needed to consider the overall connections between both the biological effects and chemical components and how food processing affects the cold-hot nature of the food.

Linking phytosterols and oxyphytosterols from food to brain health: origins, effects, and underlying mechanisms

Phytosterols and their oxidation products, namely oxyphytosterols, are natural compounds present in plant foods. With increased intake of phytosterol-enriched functional food products, the exposure of both phytosterols and oxyphytosterols is rising. Over the past ten years, researches have been focused on their absorption and metabolism in human body, as well as their biological effects. More importantly, recent studies showed that phytosterols and oxyphytosterols can traverse the blood-brain barrier and accumulate in the brain. As brain health problems resulting from ageing being more serious, attenuating central nervous system (CNS) disorders with active compounds in food are becoming a hot topic. Phytosterols and oxyphytosterols have been shown to implicated in cognition altering and the pathologies of several CNS disorders, including Alzheimer's disease and multiple sclerosis. We will overview these findings with a focus on the contents of phytosterols and oxyphytosterols in food and their dietary intake, as well as their origins in the brain, and illustrate molecular pathways through which they affect brain health, in terms of inflammation, cholesterol homeostasis, oxidative stress, and mitochondria function. The existing scientific gaps of phytosterols and oxyphytosterols to brain health in knowledge are also discussed, highlighting research directions in the future.

ShenmaYizhi Decoction Improves the Mitochondrial Structure in the Brain and Ameliorates Cognitive Impairment in VCI Rats via the AMPK/UCP2 Signaling Pathway

BACKGROUND

ShenmaYizhi decoction (SMYZD) is an effective prescription of traditional Chinese medicine used to treat vascular dementia (VD). Modern research methods have identified its active ingredients clearly as gastrodin, ferulic acid, ginsenosides, and β-sitosterol. Chronic cerebral hypoperfusion is a driving factor or risk factor for VD, which leads to the disturbance of mitochondrial structure and function.

PURPOSE

To observe whether SMYZD improves cognitive impairment by improving mitochondrial structure and function.

METHODS

Forty adult rats with vascular cognitive impairment (VCI) caused by the bilateral ligation of common carotid arteries were divided into four groups randomly, including the model group, donepezil group, and low-dose and high-dose SMYZD groups, with 10 rats in each group. Additionally, a sham group was established with 10 rats as the control group. The treatment groups were administered donepezil and two different dosages of SMYZD. The donepezil group was administered 0.45 mg/kg/d donepezil, and the SMYZ-L group was administered 2.97 g/kg/d SMYZ, which were equivalent to the clinical dosage. The SMYZ-H group was administered 11.88 g/kg/d SMYZ, which is 4 times higher than the clinically equivalent dosage. A sham-operated group was used as the control group and administered an equal volume of distilled water. The rats were treated by gavage for 8 consecutive weeks. Morris water maze (MWM) test was performed to evaluate the learning and memory ability. The mitochondria of brain tissue were extracted from brain for further test. Mitochondrial morphology and the signal path of AMPK/PPARα/PGC-1α/UCP2 in mitochondria were detected.

RESULTS

With the SMYZD intervention, behavioral performance of rats and pathological changes of mitochondria of brain tissue were significantly improved. In the serum, SOD, GSH-Px, and GSH activities were increased, and the MDA content was decreased. Moreover, the AMPK, PPARα, PGC-1α, UCP2, and ATP5A mRNA and protein expression levels were also reversed by SMYZD.

CONCLUSION

SMYZD may provide a potential therapeutic strategy via activating the AMPK/PPARα/PGC-1α/UCP2 signal pathway to improve mitochondrial structure and energy metabolism thereby alleviate vascular cognitive impairment.

Plant sterol ester of α-linolenic acid ameliorates high-fat diet-induced nonalcoholic fatty liver disease in mice: association with regulating mitochondrial dysfunction and oxidative stress via activating AMPK signaling

Plant sterol ester of α-linolenic acid prevents nonalcoholic fatty liver disease by improving mitochondrial function, modifying lipid metabolism, and inhibiting oxidative stress via AMPK signaling.

The Underlying Mechanism of Paeonia lactiflora Pall. in Parkinson's Disease Based on a Network Pharmacology Approach

Background: Parkinson's disease (PD) is the second most common neurodegenerative disease worldwide, yet as of currently, there is no disease-modifying therapy that could delay its progression. Paeonia lactiflora Pall. is the most frequently used herb in formulas for PD in Traditional Chinese Medicine and also a potential neuroprotective agent for neurodegenerative diseases, while its mechanisms remain poorly understood. In this study, we aim to explore the underlying mechanism of P. lactiflora in treating PD utilizing a network pharmacology approach. Methods: The protein targets of P. lactiflora ingredients and PD were first obtained from several databases. To clarify the key targets, a Protein-Protein-Interaction (PPI) network was constructed and analyzed on the String database, and then enrichment analysis was performed by the Metascape platform to determine the main Gene Ontology biological processes and Kyoto Encyclopedia of Genes and Genomes pathways. Finally, the Ingredient-Target-Pathway (I-T-P) network was constructed and analyzed by Cytoscape software. Results: Six active ingredients of P. lactiflora (kaempferol, ß-sitosterol, betulinic acid, palbinone, paeoniflorin and (+)-catechin) as well as six core targets strongly related to PD treatment [AKT1, interleukin-6, CAT, Tumor necrosis factor (TNF), CASP3, and PTGS2] were identified. The main pathways were shown to involve neuroactive ligand-receptor interaction, Calcium signaling pathway, PI3-Akt signaling pathway, TNF signaling pathway, and apoptosis signaling pathway. The main biological process included the regulation of neurotransmitter levels. Conclusion: P. lactiflora may retard neurodegeneration by reducing neuroinflammation, inhibiting intrinsic and extrinsic apoptosis, and may improve motor and non-motor symptoms by regulating the levels of neurotransmitters. Our study has revealed the mechanism of P. lactiflora in the treatment of PD and may contribute to novel drug development for PD.

Identification of bioactive constituents in Coldenia procumbens L. and its antidiabetic activity against streptozotocin induced Wistar albino rats

Background Type II diabetes, a multifactorial progressive disorder is the prime concern of the twenty-first century. Modern medicine is proven effective in delaying the effects of diabetes. However, the side effects are amplified over time. In order to find relief from side effects, people are rigorously searching for alternative treatment. Objective In this study, we aim to identify the bioactive components in the Coldenia procumbens L. and assess its anti-diabetic effect. Materials and Methods Initially, the plant was extracted using chloroform and methanol. Both the extracts were analysed using IR Spectrum and NMR. The methanol extract of Coldenia procumbens L. was assessed for its anti-hyperglycaemic activity against streptozotocin induced animals. Results The IR spectrum of the extracts was compared with standard compounds and four compounds, α-amyrin, β-sitosterol, β-stigmasterol and wedelolactone was identified. Methanol extract of Coldenia procumbens L. decreased glucose levels in serum and enzymes levels. Histopathology of pancreas showed excellent recovery from the damage induced by streptozotocin. Conclusion The compounds identified in Coldenia procumbens L. have significant anti-diabetic, insulin mimetic and insulin secretory activities with their complete mechanisms already studied in detail. Also, Coldenia procumbens L. methanol extract showed significant anti-hyperglycaemic activity. The plant should be further studied to be developed as an alternative medicine.

β-Sitosterol Protects against Myocardial Ischemia/Reperfusion Injury via Targeting PPARγ/NF-κB Signalling

Myocardial ischemia/reperfusion (I/R) injury is a clinically severe complication, which can cause high rates of disability and mortality particularly in patients with myocardial infarction, yet the molecular mechanisms underlying this process remain unclear. This study aimed to explore the protective effects of β-sitosterol against myocardial I/R injury and to elucidate the underlying molecular mechanisms. Our results showed that hypoxia/reoxygenation (H/R) treatment suppressed cell viability, induced cell apoptosis and reactive oxygen species production, increased caspase-3 and -9 activities, upregulated caspase-3 and -9 protein expressions, downregulated the Bcl-2 protein expression, and reduced the mitochondrial membrane potential. β-Sitosterol treatment attenuated H/R-induced cardiomyocyte injury. Moreover, β-sitosterol treatment counteracted the inhibitory effects of H/R treatment on the peroxisome proliferator-activated receptor gamma (PPARγ) expression and enhanced effects of H/R treatment on the NF-κB expression in cardiomyocytes. Furthermore, inhibition of PPARγ impaired the protective actions of β-sitosterol against H/R-induced cardiomyocyte injury. In the I/R rats, β-sitosterol treatment reduced the myocardial infarcted size and apoptosis, which was attenuated by the inhibition of PPARγ. In conclusion, our results demonstrate that β-sitosterol protected against in vitro H/R-induced cardiomyocyte injury and in vivo myocardial I/R injury. The β-sitosterol-mediated cardioprotective effects may involve the modulation of PPARγ/NF-κB signalling during myocardial I/R injury. Further studies are required to further explore the clinical application of β-sitosterol in the myocardial I/R injury.

In vitro effects of sitosterol and sitostanol on mitochondrial respiration in human brown adipocytes, myotubes and hepatocytes

Purpose

Lowering of LDL cholesterol levels by plant sterols and stanols is associated with decreased risk of cardiovascular disease in humans. Plant sterols and stanols also lower triacylglycerol (TG). However, it is not fully understood how reduction in TG is achieved and what the full potential of plant sterols and stanols is on whole-body metabolism. We here hypothesize that high levels of plant sterols and stanols stimulate whole-body energy expenditure, which can be attributed to changes in mitochondrial function of brown adipose tissue (BAT), skeletal muscle and liver.

Methods

Phytosterolemic mice were fed chow diets for 32 weeks to examine whole-body weight gain. In vitro, 24-h incubation were performed in adipocytes derived from human BAT, human myotubes or HepG2 human hepatocytes using sitosterol or sitostanol. Following mitochondrial function was assessed using seahorse bioanalyzer.

Results

Chow feeding in phytosterolemic mice resulted in diminished increase in body weight compared to control mice. In vitro, sitosterol or sitostanol did not change mitochondrial function in adipocytes derived from human BAT or in cultured human myotubes. Interestingly, maximal mitochondrial function in HepG2 human hepatocytes was decreased following sitosterol or sitostanol incubation, however, only when mitochondrial function was assessed in low glucose-containing medium.

Conclusions

Beneficial in vivo effects of plant sterols and stanols on lipid and lipoprotein metabolism are well recognized. Our results indicate that alterations in human mitochondrial function are apparently not involved to explain these beneficial effects.

Inhibition of mitochondrial respiration prevents BRAF-mutant melanoma brain metastasis

Melanoma patients carry a high risk of developing brain metastases, and improvements in survival are still measured in weeks or months. Durable disease control within the brain is impeded by poor drug penetration across the blood-brain barrier, as well as intrinsic and acquired drug resistance. Augmented mitochondrial respiration is a key resistance mechanism in BRAF-mutant melanomas but, as we show in this study, this dependence on mitochondrial respiration may also be exploited therapeutically. We first used high-throughput pharmacogenomic profiling to identify potentially repurposable compounds against BRAF-mutant melanoma brain metastases. One of the compounds identified was β-sitosterol, a well-tolerated and brain-penetrable phytosterol. Here we show that β-sitosterol attenuates melanoma cell growth in vitro and also inhibits brain metastasis formation in vivo. Functional analyses indicated that the therapeutic potential of β-sitosterol was linked to mitochondrial interference. Mechanistically, β-sitosterol effectively reduced mitochondrial respiratory capacity, mediated by an inhibition of mitochondrial complex I. The net result of this action was increased oxidative stress that led to apoptosis. This effect was only seen in tumor cells, and not in normal cells. Large-scale analyses of human melanoma brain metastases indicated a significant role of mitochondrial complex I compared to brain metastases from other cancers. Finally, we observed completely abrogated BRAF inhibitor resistance when vemurafenib was combined with either β-sitosterol or a functional knockdown of mitochondrial complex I. In conclusion, based on its favorable tolerability, excellent brain bioavailability, and capacity to inhibit mitochondrial respiration, β-sitosterol represents a promising adjuvant to BRAF inhibitor therapy in patients with, or at risk for, melanoma brain metastases.

Dietary β-Sitosterol Improves Growth Performance, Meat Quality, Antioxidant Status, and Mitochondrial Biogenesis of Breast Muscle in Broilers

Simple Summary

Fast growth of modern broilers induces their muscle abnormality and myopathy, and therefore could compromise meat quality attributes. Antibiotic growth promoters have been banned by European Union and restricted by other countries in livestock production due to the public concern about food safety and antibiotic resistance. The search for efficacious, environmentally friendly, safe, and consumer favorable feed additives have become a necessity to poultry meat production. β-sitosterol—the most abundant phytosterol similar to cholesterol in chemical structure—is found in several plant products. It was incorporated at four levels into broiler diets (40, 60, 80, and 100 mg/kg). Dietary β-sitosterol supplementation improved growth performance and breast muscle meat quality of broilers, and the improved meat quality may be related with the simultaneously enhanced oxidative status and mitochondrial biogenesis in the breast muscle. The β-sitosterol dietary supplementation at the level of 80 mg/kg is recommended in broilers

Abstract

The present study evaluated effects of β-sitosterol on growth performance, meat quality, oxidative status, and mitochondrial biogenesis of breast muscle in broilers. One-day-old chicks were allocated to five treatments of six replicates. Broilers were fed a basal diet supplemented either with 0 (control), 40, 60, 80, or 100 mg/kg β-sitosterol for 42 days. β-sitosterol linearly and quadratically reduced feed/gain ratio, lightness_24h and cooking loss_24h in breast muscle, whereas 2, 2-diphenyl-1-picrylhydrazyl scavenging activity of breast muscle followed an opposite trend. β-sitosterol linearly decreased drip loss_24h and malondialdehyde content, whereas linearly increased pH_24h, superoxide dismutase activity, and mRNA abundances of peroxisome proliferator-activated receptor γ coactivator 1α (PCG-1α) and mitochondrial transcription factor A (TFAM) in breast muscle. Compared with control, levels of β-sitosterol higher than 40 mg/kg reduced feed/gain ratio, muscular lightness_24h, cooking loss_24h, and malondialdehyde level, whereas increased muscular 2, 2-diphenyl-1-picrylhydrazyl scavenging activity, and mRNA abundances (except 60 mg/kg) of PCG-1α and TFAM. Eighty milligram/kilogram β-sitosterol increased muscular pH_24h and superoxide dismutase activity, but decreased its drip loss_24h. Therefore, β-sitosterol could improve growth performance and meat quality, oxidative status, and mitochondrial biogenesis of breast muscle in broilers. Furthermore, supplementation level of 80 mg/kg β-sitosterol is recommended for broiler diets.

Lipid-protein interactions in mitochondrial membranes from bivalve mollusks: molecular strategies in different species

The mitochondrial F1FO-ATPase, the key enzyme in cell bioenergetics, apparently works in the same way in mollusks and in mammals. We previously pointed out a raft-like arrangement in mussel gill mitochondrial membranes, which apparently distinguishes bivalve mollusks from mammals. To explore the relationship between the microenvironmental features and the enzyme activity, the physico-chemical features of mitochondrial membranes and the F1FO-ATPase activity temperature-dependence are here explored in the Manila clam (Ruditapes philippinarum). Similarly to the mussel, clam gill mitochondrial membrane lipids exhibit a high sterol content (42 mg/g protein), mainly due to phytosterols (cholesterol only attains 42% of total sterols), and abundant polyunsaturated fatty acids (PUFA) (70% of total fatty acids), especially of the n-3 family. However, the F1FO-ATPase activation energies above and below the break in the Arrhenius plot (22.1 °C) are lower than in mussel and mammalian mitochondria. Laurdan fluorescence spectroscopy analyses carried out at 10 °C, 20 °C and 30 °C on mitochondrial membranes and on lipid vesicles obtained from total lipid extracts of mitochondria, indicate a physical state without coexisting domains. This mitochondrial membrane constitution, allowed by lipid-lipid and lipidprotein interactions and involving PUFA-rich phospholipids, phytosterols (much more diversified in clams than in mussels) and proteins, enables the maintenance of a homogeneous physical state in the range 10-30 °C. Consistently, this molecular interaction network would somehow extend the temperature range of the F1FO-ATPase activity and may contribute to clam resilience to temperature changes.

Major compounds of red ginseng oil attenuate Aβ25-35-induced neuronal apoptosis and inflammation by modulating MAPK/NF-κB pathway

β-Amyloid (Aβ)-induced neuronal toxicity in Alzheimer's disease (AD) is associated with complex mechanisms. Thus, a multi-target approach might be suitable for AD treatment. Following our previous study on the neuroprotective effects of red ginseng oil extract, its major compounds, including linoleic acid (LA), β-sitosterol (BS), and stigmasterol (SS), were examined to elucidate the mechanism of anti-apoptosis and anti-inflammation in Aβ25-35-stimulated PC12 cells. The results showed that the three compounds mitigated Aβ25-35 toxicity by regulating oxidative stress, apoptotic responses, and pro-inflammatory mediators. LA and SS strongly regulated intrinsic apoptosis markers, such as mitochondrial membrane potential, intracellular Ca2+, Bax/Bcl-2 ratio, and caspases-9, -3, and -8. However, BS blocked only the intrinsic apoptotic pathway, particularly by suppressing Ca2+ accumulation. Furthermore, all three compounds downregulated iNOS and phospho-nuclear factor-κB, but only LA and SS inhibited the expression of cyclooxygenase-2 and phospho-IκB. In assays to evaluate MAPK expression for confirming upstream signal pathways, BS decreased the phosphorylation of p38 and ERK, but not JNK, while SS markedly decreased the phosphorylation of all three MAPKs, and LA clearly decreased the phosphorylation of ERK and JNK, but not p38. These results indicate that LA, BS, and SS act as neuroprotectives against Aβ25-35-induced injury by distinct molecular mechanisms, indicating their preventive and/or therapeutic potential to treat AD.

Glucocerebrosidase Mutations and Synucleinopathies. Potential Role of Sterylglucosides and Relevance of Studying Both GBA1 and GBA2 Genes

Gaucher's disease (GD) is the most prevalent lysosomal storage disorder. GD is caused by homozygous mutations of the GBA1 gene, which codes for beta-glucocerebrosidase (GCase). Although GD primarily affects peripheral tissues, the presence of neurological symptoms has been reported in several GD subtypes. GBA1 mutations have recently deserved increased attention upon the demonstration that both homo- and heterozygous GBA1 mutations represent the most important genetic risk factor for the appearance of synucleinopathies like Parkinson's disease (PD) and dementia with Lewy bodies (LBD). Although reduced GCase activity leads to alpha-synuclein aggregation, the mechanisms sustaining a role for GCase in alpha-synuclein homeostasis still remain largely unknown. Furthermore, the role to be played by impairment in the physiological function of endoplasmic reticulum, mitochondria and other subcellular membranous components is currently under investigation. Here we focus on the impact of GCase loss-of-function that impact on the levels of sterylglucosides, molecules that are known to trigger a PD-related synucleinopathy upon administration in rats. Moreover, the concurrence of another gene also coding for an enzyme with GCase activity (GBA2 gene) should also be taken into consideration, bearing in mind that in addition to a hydrolytic function, both GCases also share transglycosylation as a second catalytic activity. Accordingly, sterylglycoside levels should also be considered to further assess their impact on the neurodegenerative process. In this regard-and besides GBA1 genotyping-we suggest that screening for GBA2 mutations should be considered, together with analytical measurements of cholesterol glycosides in body fluids, as biomarkers for both PD risk and disease progression.

Pre-Treatment with Either L-Carnitine or Piracetam Increases Ultrasound-Mediated Gene Transfection by Reducing Sonoporation-Associated Apoptosis

Sonoporation, the use of ultrasound to alter the permeability of cell membranes, is a non-viral technique used to facilitate gene delivery, possibly by opening transient pores in the cell membrane. However, sonoporation may have negative bio-effects on cells, such as causing apoptosis, which limits its efficacy in gene delivery. In this study, we investigated whether pre-treatment with either L-carnitine or piracetam could protect cells from undergoing apoptosis after sonoporation and the possible mechanisms. We found that either L-carnitine or piracetam can promote gene transfection without reducing cell viability, possibly by reducing cavitation-induced reactive oxygen species generation, reversing alterations of mitochondrial membrane potential, preventing caspase-3/7 activity and facilitating mitochondrial ATP production. In conclusion, pre-treatment with either L-carnitine or piracetam could protect cells from sonoporation-associated apoptosis by preserving mitochondrial function.

17β-Estradiol Directly Lowers Mitochondrial Membrane Microviscosity and Improves Bioenergetic Function in Skeletal Muscle

Menopause results in a progressive decline in 17β-estradiol (E2) levels, increased adiposity, decreased insulin sensitivity, and a higher risk for type 2 diabetes. Estrogen therapies can help reverse these effects, but the mechanism(s) by which E2 modulates susceptibility to metabolic disease is not well understood. In young C57BL/6N mice, short-term ovariectomy decreased-whereas E2 therapy restored-mitochondrial respiratory function, cellular redox state (GSH/GSSG), and insulin sensitivity in skeletal muscle. E2 was detected by liquid chromatography-mass spectrometry in mitochondrial membranes and varied according to whole-body E2 status independently of ERα. Loss of E2 increased mitochondrial membrane microviscosity and H₂O₂ emitting potential, whereas E2 administration in vivo and in vitro restored membrane E2 content, microviscosity, complex I and I + III activities, H₂O₂ emitting potential, and submaximal OXPHOS responsiveness. These findings demonstrate that E2 directly modulates membrane biophysical properties and bioenergetic function in mitochondria, offering a direct mechanism by which E2 status broadly influences energy homeostasis.

Critical Analysis on Characterization, Systemic Effect, and Therapeutic Potential of Beta-Sitosterol: A Plant-Derived Orphan Phytosterol

Beta-sitosterol (BS) is a phytosterol, widely distributed throughout the plant kingdom and known to be involved in the stabilization of cell membranes. To compile the sources, physical and chemical properties, spectral and chromatographic analytical methods, synthesis, systemic effects, pharmacokinetics, therapeutic potentials, toxicity, drug delivery and finally, to suggest future research with BS, classical as well as on-line literature were studied. Classical literature includes classical books on ethnomedicine and phytochemistry, and the electronic search included Pubmed, SciFinder, Scopus, the Web of Science, Google Scholar, and others. BS could be obtained from different plants, but the total biosynthetic pathway, as well as its exact physiological and structural function in plants, have not been fully understood. Different pharmacological effects have been studied, but most of the mechanisms of action have not been studied in detail. Clinical trials with BS have shown beneficial effects in different diseases, but long-term study results are not available. These have contributed to its current status as an "orphan phytosterol". Therefore, extensive research regarding its effect at cellular and molecular level in humans as well as addressing the claims made by commercial manufacturers such as the cholesterol lowering ability, immunological activity etc. are highly recommended.

Hypobaric Treatment Effects on Chilling Injury, Mitochondrial Dysfunction, and the Ascorbate-Glutathione (AsA-GSH) Cycle in Postharvest Peach Fruit

In this study, hypobaric treatment effects were investigated on chilling injury, mitochondrial dysfunction, and the ascorbate-glutathione (AsA-GSH) cycle in peach fruit stored at 0 °C. Internal browning of peaches was dramatically reduced by applying 10-20 kPa pressure. Hypobaric treatment markedly inhibited membrane fluidity increase, whereas it kept mitochondrial permeability transition pore (MPTP) concentration and cytochrome C oxidase (CCO) and succinic dehydrogenase (SDH) activity relatively high in mitochondria. Similarly, 10-20 kPa pressure treatment reduced the level of decrease observed in AsA and GSH concentrations, while it enhanced ascorbate peroxidase (APX), glutathione reductase (GR), and monodehydroascorbate reductase (MDHAR) activities related to the AsA-GSH cycle. Furthermore, comparative transcriptomic analysis showed that differentially expressed genes (DEGs) associated with the metabolism of glutathione, ascorbate, and aldarate were up-regulated in peaches treated with 10-20 kPa for 30 days at 0 °C. Genes encoding GR, MDHAR, and APX were identified and exhibited higher expression in fruits treated with low pressure than in fruits treated with normal atmospheric pressure. Our findings indicate that the alleviation of chilling injury by hypobaric treatment was associated with preventing mitochondrial dysfunction and triggering the AsA-GSH cycle by the transcriptional up-regulation of related enzymes.

A Cistanches Herba Fraction/ β -Sitosterol Causes a Redox-Sensitive Induction of Mitochondrial Uncoupling and Activation of Adenosine Monophosphate-Dependent Protein Kinase/Peroxisome Proliferator-Activated Receptor γ Coactivator-1 in C2C12 Myotubes: A Possible Mechanism Underlying the Weight Reduction Effect

Previous studies have demonstrated that HCF1, a semipurified fraction of Cistanches Herba, causes weight reduction in normal diet- and high fat diet-fed mice. The weight reduction was associated with the induction of mitochondrial uncoupling and changes in metabolic enzyme activities in mouse skeletal muscle. To further investigate the biochemical mechanism underlying the HCF1-induced weight reduction, the effect of HCF1 and its active component, β-sitosterol (BSS), on C2C12 myotubes was examined. Incubation with HCF1/BSS caused a transient increase in mitochondrial membrane potential (MMP), possibly by fluidizing the mitochondrial inner membrane. The increase in MMP was paralleled to an increase in mitochondrial reactive oxygen species (ROS) production. Mitochondrial ROS, in turn, triggered a redox-sensitive induction of mitochondrial uncoupling by uncoupling protein 3 (UCP3). Biochemical analysis indicated that HCF1 was capable of activating an adenosine monophosphate-dependent protein kinase/peroxisome proliferator-activated receptor γ coactivator-1 pathway and thereby increased the expression of cytochrome c oxidase and UCP3. Animal studies using mitochondrial recoupler also confirmed the role of mitochondrial uncoupling in the HCF1-induced weight reduction. In conclusion, a HCF1/BSS causes the redox-sensitive induction of mitochondrial uncoupling and activation of AMPK/PGC-1 in C2C12 myotubes, with resultant reductions in body weight and adiposity by increased energy consumption.

Mitochondrial reactive oxygen species production mediates ursolic acid-induced mitochondrial uncoupling and glutathione redox cycling, with protection against oxidant injury in H9c2 cells

Ursolic acid (UA), a natural pentacyclic triterpenoid carboxylic acid, is a ubiquitous compound widely distributed in many plants, fruits and medicinal herbs worldwide. A previous study in our laboratory has shown that UA can increase the mitochondrial ATP generation capacity (ATP-GC) and a glutathione-dependent antioxidant response, thereby protecting against oxidant injury in H9c2 cells in vitro and rat hearts ex vivo. However, the mechanism underlying the cellular protective effects induced by UA remains largely unknown. The present study has shown that pre-incubation with UA produces a transient increase in the mitochondrial membrane potential in H9c2 cells, which was accompanied by increases in mitochondrial reactive oxygen species (ROS) production. Studies using an antioxidant (dimethylthiourea) indicated that the suppression of mitochondrial ROS completely abrogated the UA-induced enhancement of mitochondrial uncoupling and glutathione reductase (GR)-mediated glutathione redox cycling, as well as protection against menadione cytotoxicity in H9c2 cells. Co-incubation with specific inhibitors of uncoupling proteins and GR almost completely prevented the cytoprotection afforded by UA against menadione-induced cytotoxicity in H9c2 cells. The results obtained so far suggest that UA-induced mitochondrial ROS production can elicit mitochondrial uncoupling and glutathione-dependent antioxidant responses, which offer cytoprotection against oxidant injury in H9c2 cells.

New insights into the chemical and biochemical basis of the "yang-invigorating" action of chinese yang-tonic herbs

In the practice of traditional Chinese medicine, many Yang-tonic herbs have been used for retarding the decline in bodily function and delaying the onset of age-related diseases. Our earlier studies have demonstrated that Yang-invigorating herbs/formulations protect against oxidative injury in various organs and also extend the median lifespan in mice. This lifespan extension was associated with an upregulation of cellular antioxidant status including that of mitochondria whose functional capacity is also increased by “Yang-invigorating” herbs/formulations. In this paper, we propose that triterpenes and phytosterols, which are ubiquitously found in Yang-tonic herbs, may be the chemical entities responsible for enhancing mitochondrial functional and antioxidant capacity and thus the “Yang-invigorating” action. The biochemical mechanism underlying this “Yang-invigorating” action may involve a sustained production of low levels of mitochondrial reactive oxygen species (ROS) secondary to an increased activity of the electron transport chain, with the possible involvement of mitochondrial uncoupling. The increase in mitochondrial functional capacity can retard the decline in bodily function during aging, whereas the mitochondrial ROS production is instrumental in eliciting a glutathione antioxidant response via redox-sensitive signaling pathways, which can delay the onset of age-related diseases.

Biological activities of Schottenol and Spinasterol, two natural phytosterols present in argan oil and in cactus pear seed oil, on murine miroglial BV2 cells

The objective of this study was to evaluate the biological activities of the major phytosterols present in argan oil (AO) and in cactus seed oil (CSO) in BV2 microglial cells. Accordingly, we first determined the sterol composition of AO and CSO, showing the presence of Schottenol and Spinasterol as major sterols in AO. While in CSO, in addition to these two sterols, we found mainly another sterol, the Sitosterol. The chemical synthesis of Schottenol and Spinasterol was performed. Our results showed that these two phytosterols, as well as sterol extracts from AO or CSO, are not toxic to microglial BV2 cells. However, treatments by these phytosterols impact the mitochondrial membrane potential. Furthermore, both Schottenol and Spinasterol can modulate the gene expression of two nuclear receptors, liver X receptor (LXR)-α and LXRβ, their target genes ABCA1 and ABCG1. Nonetheless, only Schottenol exhibited a differential activation vis-à-vis the nuclear receptor LXRβ. Thus Schottenol and Spinasterol can be considered as new LXR agonists, which may play protective roles by the modulation of cholesterol metabolism.

Membrane composition and dynamics: a target of bioactive virgin olive oil constituents

The endogenous synthesis of lipids, which requires suitable dietary raw materials, is critical for the formation of membrane bilayers. In eukaryotic cells, phospholipids are the predominant membrane lipids and consist of hydrophobic acyl chains attached to a hydrophilic head group. The relative balance between saturated, monounsaturated, and polyunsaturated acyl chains is required for the organization and normal function of membranes. Virgin olive oil is the richest natural dietary source of the monounsaturated lipid oleic acid and is one of the key components of the healthy Mediterranean diet. Virgin olive oil also contains a unique constellation of many other lipophilic and amphipathic constituents whose health benefits are still being discovered. The focus of this review is the latest evidence regarding the impact of oleic acid and the minor constituents of virgin olive oil on the arrangement and behavior of lipid bilayers. We highlight the relevance of these interactions to the potential use of virgin olive oil in preserving the functional properties of membranes to maintain health and in modulating membrane functions that can be altered in several pathologies. This article is part of a Special Issue entitled: Membrane Structure and Function: Relevance in the Cell's Physiology, Pathology and Therapy.