Search

Abstract Fibrosis is associated with compromised muscle functionality in Duchenne muscular dystrophy (DMD). We report observations with tissues from dystrophic patients and mice supporting a model to explain fibrosis in DMD, which relies on the crosstalk between the complement and the WNT signaling pathways and the functional interactions of two cellular types. Fibro‐adipogenic progenitors and macrophages, which populate the inflamed dystrophic muscles, act as a combinatorial source of WNT activity by secreting distinct subunits of the C1 complement complex. The resulting aberrant activation of the WNT signaling in responsive cells, such as fibro‐adipogenic progenitors, contributes to fibrosis. Indeed, pharmacological inhibition of the C1r/s subunits in a murine model of DMD mitigated the activation of the WNT signaling pathway, reduced the fibrogenic characteristics of the fibro‐adipogenic progenitors, and ameliorated the dystrophic phenotype. These studies shed new light on the molecular and cellular mechanisms responsible for fibrosis in muscular dystrophy and open to new therapeutic strategies.

Milk thistle seed oil is still not a well-known edible oil. Silybum marianum (milk thistle), is present in several countries and is the only known representative of the genus Silybum. However, Silybum eburneum, which is an endemic plant in Spain, Kenya, Morocco, Algeria, and Tunisia, is considered a marginalized species. The present work is the first report that gives information on the lipid and phenolic profiles of Tunisian S. eburneum seed oil compared to those of Tunisian S. marianum seed oil. In addition, the antioxidant properties of these oils were determined with DPPH, FRAP, and KRL assays, and their ability to prevent oxidative stress was determined on human monocytic THP-1 cells. These oils are characterized by high amounts of unsaturated fatty acids; linoleic acid and oleic acid are the most abundant. Campesterol, sitosterol, stigmasterol, and β-amyrin were the major phytosterols identified. α-tocopherol was the predominant tocopherol found. These oils also contain significant amounts of phenolic compounds. The diversity and richness of Silybum marianum and Silybum eburneum seed oils in unsaturated fatty acids, phenolic compounds, and tocopherols are associated with high antioxidant activities revealed by the DPPH, FRAP, and KRL assays. In addition, on THP-1 cells, these oils powerfully reduced the oxidative stress induced by 7-ketocholesterol and 7β-hydroxycholesterol, two strongly pro-oxidant oxysterols often present at increased levels in patients with age-related diseases. Silybum marianum and Silybum eburneum seed oils are therefore important sources of bioactive molecules with nutritional interest that prevent age-related diseases, the frequency of which is increasing in all countries due to the length of life expectancy.

7-ketocholesterol is a cytotoxic oxysterol which is frequently increased in many chronic inflammatory and age-related diseases. Thus, the inhibition of the toxicity of 7-ketocholesterol is a major challenge to treat these diseases. 158N oligodendrocytes were used to evaluate the cytoprotective effects of lipids: ω-3 and ω-9 fatty acids (α-linolenic acid (C18:3n-3), eicosapentaenoic acid (C20:5n-3), docosahexaenoic acid (C22:6n-3), erucic acid (C22:1n-9) and oleic acid (C18:1n-9)), Lorenzo's oil (a mixture of oleic and erucic acid, 4:1) and sulfo-N-succinimidyl oleate (SSO, a synthetic derivative of oleic acid). On 158N cells, the ability of these molecules to inhibit 7KC-induced oxiapoptophagy (plasma membrane alteration, loss of ΔΨm, peroxisomal dysfunction, reactive oxygen species overproduction, induction of apoptosis and autophagy) were determined. ARPE-19 epithelial retinal cells were also used to evaluate the cytoprotective effect of SSO on 7KC-induced cell death. Unlike ω-3 and ω-9 fatty acids and Lorenzo's oil, sulfo-N-succinimidyl oleate had no cytotoxic effects over a wide range of concentrations. Noteworthy, unlike fatty acids and Lorenzo's oil, the cytoprotective effects of sulfo-N-succinimidyl oleate on 7KC-induced oxiapoptophagy, a caspase-dependent mode of cell death on 158N cells, were not associated with an accumulation of lipid droplets. In addition, on ARPE-19 cells, sulfo-N-succinimidyl oleate prevented 7KC-induced oxidative stress and cell death. These different characteristics of SSO make it possible to envisage its use for therapeutic purposes in diseases where 7-ketocholesterol levels are increased without eventual secondary side effects due to lipid droplets formation.

On murine N2a cells, 7-ketocholesterol induced an oxiapotophagic mode of cell death characterized by oxidative stress (reactive oxygen species overproduction on whole cells and at the mitochondrial level; lipid peroxidation), apoptosis induction (caspase-9, −3 and −7 cleavage, PARP degradation) and autophagy (increased ratio LC3-II / LC3-I). Oxidative stress was strongly attenuated by diphenyleneiodonium chloride which inhibits NAD(P)H oxidase. Mitochondrial and peroxisomal morphological and functional changes were also observed. Down regulation of PDK1 / Akt signaling pathways as well as of GSK3 / Mcl-1 and Nrf2 pathways were simultaneously observed in 7-ketocholesterol-induced oxiapoptophagy. These events were prevented by α-linolenic acid, eicosapentaenoic acid, docosahexaenoic acid, oleic acid and α-tocopherol. The inhibition of the cytoprotection by LY-294002, a PI3-K inhibitor, demonstrated an essential role of PI3-K in cell rescue. The rupture of oxidative stress in 7-ketocholesterol-induced oxiapoptophagy was also associated with important modifications of glutathione peroxidase, superoxide dismutase and catalase activities as well as of glutathione peroxidase-1, superoxide dismutase-1 and catalase level and expression. These events were also counteracted by α-linolenic acid, eicosapentaenoic acid, docosahexaenoic acid, oleic acid and α-tocopherol. The inhibition of the cytoprotection by mercaptosuccinic acid, a glutathione peroxidase inhibitor, showed an essential role of this enzyme in cell rescue. Altogether, our data support that the reactivation of PI3-K and glutathione peroxidase activities by α-linolenic acid, eicosapentaenoic acid, docosahexaenoic acid, oleic acid and α-tocopherol are essential to prevent 7KC-induced oxiapoptophagy.

Silybum marianum and Silybum eburneum are wild edible Mediterranean plants used in the human diet. This study presents the initial findings on the phytochemical characterization of Tunisian S. marianum and S. eburneum organs. It examined their mineral, sugar, organic acid, polyphenolic, and seed storage protein contents, as well as their antioxidant potential. In S. marianum, stems had high sodium and potassium contents, while the immature and mature seeds were rich in calcium and magnesium. However, S. eburneum had high potassium levels in stems and high sodium and calcium levels in the flowers. S. marianum showed substantial fructose variation among its organs. Conversely, S. eburneum exhibited significant heterogeneity in glucose, sucrose, and maltose levels across its organs, with maltose exclusively detected in the immature seeds. A notable organ-dependent distribution of organic acids was observed among the two species. Higher levels of phenolic contents were detected in both mature and immature seeds in both species compared to the other plant parts. The seeds possessed higher antioxidant activities than other plant organs. In both S. marianum and S. eburneum seeds, albumins and globulins were the predominant protein fractions. This study brings evidence supporting the important potential of Silybum organs as sources of nutrients with antioxidant properties for producing functional food.

Thymus atlanticus (Lamiaceae) is a plant endemic to the Mediterranean basin that is found in significant quantities in the arid regions of Morocco. Thymus atlanticus is used in traditional medicine to treat infectious and non-infectious diseases. It is also used for the isolation of essential oils and for the seasoning of many dishes in the Mediterranean diet. The major constituents of Thymus atlanticus are saponins, flavonoids, tannins, alkaloids, various simple and hydroxycinnamic phenolic compounds, and terpene compounds. Several of these compounds act on signaling pathways of oxidative stress, inflammation, and blood sugar, which are parameters often dysregulated during aging. Due to its physiochemical characteristics and biological activities, Thymus atlanticus could be used for the prevention and/or treatment of age-related diseases. These different aspects are treated in the present review, and we focused on phytochemistry and major age-related diseases: dyslipidemia, cardiovascular diseases, and type 2 diabetes.

Trans-resveratrol (RSV) is a non-flavonoid polyphenol (stilbene) with numerous biological activities, such as anti-tumor activities. However, RSV is rapidly metabolized, which limits its therapeutic use. The availability of RSV analogues with similar activities for use in vivo is therefore a major challenge. For this purpose, several isomeric analogues of RSV, aza-stilbenes (AZA-ST 1a–g), were synthesized, and their toxicities were characterized and compared to those of RSV on murine N2a neuronal cells using especially flow cytometric methods. All AZA-ST 1a–g have an inhibitory concentration 50 (IC50) between 11.3 and 25 µM when determined by the crystal violet assay, while that of RSV is 14.5 µM. This led to the characterization of AZA-ST 1a–g—induced cell death, compared to RSV, using three concentrations encompassing the IC50s (6.25, 12.5 and 25 µM). For AZA-ST 1a–g and RSV, an increase in plasma membrane permeability to propidium iodide was observed, and the proportion of cells with depolarized mitochondria measured with DiOC6(3) was increased. An overproduction of reactive oxygen species (ROS) was also observed on whole cells and at the mitochondrial level using dihydroethidium and MitoSox Red, respectively. However, only RSV induced a mode of cell death by apoptosis associated with a marked increase in the proportion of cells with condensed and/or fragmented nuclei (12.5 µM: 22 ± 9%; 25 µM: 80 ± 10%) identified after staining with Hoechst 33342 and which are characteristic of apoptotic cells. With AZA-ST, a slight but significant increase in the percentage of apoptotic cells was only detected with AZA-ST 1b (25 µM: 17 ± 1%) and AZA-ST 1d (25 µM: 26 ± 4%). Furthermore, only RSV induced significant cell cycle modifications associated with an increase in the percentage of cells in the S phase. Thus, AZA-ST 1a–g—induced cell death is characterized by an alteration of the plasma membrane, an induction of mitochondrial depolarization (loss of ΔΨm), and an overproduction of ROS, which may or may not result in a weak induction of apoptosis without modification of the distribution of the cells in the different phases of the cell cycle.

Due to the increase in life span and life expectancy, which can, however, be more or less pronounced depending on the economic, social and cultural context [...]

Trans-resveratrol is a natural polyphenol showing numerous biological properties, especially anti-tumoral and antioxidant activity. Among numerous resveratrol derivatives, aza-stilbenes, which bear an imine bound, show interesting biological activities. In the present study, we synthesized a series of imine analogs of trans-resveratrol (seven aza-stilbenes) following an easy and low-cost procedure of green chemistry. The toxicity of synthesized aza-stilbenes, which is currently unknown, was evaluated on murine neuronal N2a cells, comparatively to trans-resveratrol, by considering: cell density evaluated by staining with sulforhodamine 101; esterase activity, which is a criteria of cell viability, by staining with fluorescein diacetate; and transmembrane mitochondrial potential, which is known to decrease during cell death, by staining with DiOC6(3) using flow cytometry. In addition, the antioxidant activity was quantified with the KRL (Kit Radicaux Libres) assay, the DPPH (2,2′-diphenyl-1-picrylhydrazyl radical) assay and the FRAP (ferric reducing antioxidant power) assay. The PAOT (Pouvoir Antioxidant Total) score was also used. The aza-stilbenes provide different cytotoxic and antioxidant activities, which are either higher or lower than those of trans-resveratrol. Based on their cytotoxic and antioxidant characteristics, all synthesized aza-stilbenes are distinguished from trans-resveratrol.

Coronavirus illness (COVID-19) is an infectious pathology generated by intense severe respiratory syndrome coronavirus 2 (SARS-CoV-2). This infectious disease has emerged in 2019. The COVID-19-associated pandemic has considerably affected the way of life and the economy in the world. It is consequently crucial to find solutions allowing remedying or alleviating the effects of this infectious disease. Natural products have been in perpetual application from immemorial time given that they are attested to be efficient towards several illnesses without major side effects. Various studies have shown that plant extracts or purified molecules have a promising inhibiting impact towards coronavirus. In addition, it is substantial to understand the characteristics, susceptibility and impact of diet on patients infected with COVID-19. In this review, we recapitulate the influence of extracts or pure molecules from medicinal plants on COVID-19. We approach the possibilities of plant treatment/co-treatment and feeding applied to COVID-19. We also show coronavirus susceptibility and complications associated with nutrient deficiencies and then discuss the major food groups efficient on COVID-19 pathogenesis. Then, we covered emerging technologies using plant-based SARS-CoV-2 vaccine. We conclude by giving nutrient and plants curative therapy recommendations which are of potential interest in the COVID-19 infection and could pave the way for pharmacological treatments or co-treatments of COVID-19.

Plants are an important source of pharmacologically active compounds. In the present work, we characterize the impact of black cumin (Nigella sativa L.) aqueous extracts on a yeast model of p53-dependent apoptosis. To this end, the Saccharomyces cerevisiae recombinant strain over-expressing p53 was used. The over-expression of p53 triggers the expression of apoptotic markers: the externalization of phosphatidylserine, mitochondrial defect associated with cytochrome-c release and the induction of DNA strand breaks. These different effects were attenuated by Nigella sativa L. aqueous extracts, whereas these extracts have no effect on the level of p53 expression. Thus, we focus on the anti-apoptotic molecules present in the aqueous extract of Nigella sativa L. These extracts were purified and characterized by complementary chromatographic methods. Specific fluorescent probes were used to determine the effect of the extracts on yeast apoptosis. Yeast cells over-expressing p53 decrease in relative size and have lower mitochondrial content. The decrease in cell size was proportional to the decrease in mitochondrial content and of mitochondrial membrane potential (ΔΨm). These effects were prevented by the purified aqueous fraction obtained by fractionation with different columns, named C4 fraction. Yeast cell death was also characterized by reactive oxygen species (ROS) overproduction. In the presence of the C4 fraction, ROS overproduction was strongly reduced. We also noted that the C4 fraction promotes the cell growth of control yeast cells, which do not express p53, supporting the fact that this purified extract acts on cellular mediators activating cell proliferation independently of p53. Altogether, our data obtained on yeast cells over-expressing p53 demonstrate that anti-apoptotic molecules targeting p53-induced apoptosis associated with mitochondrial dysfunction and ROS overproduction are present in the aqueous extracts of Nigella seeds and in the purified aqueous C4 fraction.

The present study was undertaken to evaluate serum levels of pro-inflammatory cytokines in Tunisian older adults and to examine the relationships between inflammatory marker levels, geriatric, and biochemical parameters. A cross-sectional study was conducted in a population of Tunisian older adults (N = 141, aged 65 and over). Patients were recruited from the Department of Internal Medicine, Fattouma Bourguiba University Hospital (Monastir, Tunisia) and from a nursing home (Sousse, Tunisia). Comprehensive geriatric assessment, history taking and examination including functional and nutritional assessment were done for each participant. Enzyme-linked immunosorbent assay (ELISA) test was used to measure serum cytokine (TNF-α, IL-8, IL-6) levels. The modified Short Emergency Geriatric Assessment score (SEGAm) were used to classify patients as 51 very-frail, 40 frail, and 50 non-frail. The age of the participants (80 men, 61 women) ranged from 65 to 97 years. Serum levels of TNF-α, IL-8 and C-reactive protein (CRP) were significantly higher in very-frail participants compared to frail and non-frail ones. However, no significant differences in IL-6 levels were detected among frailty groups. After adjustment for age, CRP and IL-8 levels remained significantly associated with frailty. Analysis of the receiver operating characteristic (ROC) curve corresponding to IL-8 showed an area under the curve of 0.7 (p = 0.003; 95% CI [0.58-0.81]) and a predictive threshold of 5.27 pg/ml. Positive correlations were found between frailty score, IL-6, and IL-8 levels. In addition, a significant positive correlation was observed between IL-8 levels and Timed Up and Go test results. However, a negative correlation was observed between Mini Nutritional Assessment Short-Form score, IL-6 and CRP levels, as well as between Activities of Daily Living score and serum levels of TNF-α, IL-6, and CRP. In conclusion, the key findings of this study collectively support a role of pro-inflammatory cytokines, TNF-α, CRP, and especially IL-8 in the development of frailty in older adults.

Mitochondria are multifunctional organelles that participate in a wide range of metabolic processes, including energy production and biomolecule synthesis. The morphology and distribution of intracellular mitochondria change dynamically, reflecting a cell’s metabolic activity. Oxidative stress is defined as a mismatch between the body’s ability to neutralise and eliminate reactive oxygen and nitrogen species (ROS and RNS). A determination of mitochondria failure in increasing oxidative stress, as well as its implications in neurodegenerative illnesses and apoptosis, is a significant developmental process of focus in this review. The neuroprotective effects of bioactive compounds linked to neuronal regulation, as well as related neuronal development abnormalities, will be investigated. In conclusion, the study of secondary components and the use of mitochondrial features in the analysis of various neurodevelopmental diseases has enabled the development of a new class of mitochondrial-targeted pharmaceuticals capable of alleviating neurodegenerative disease states and enabling longevity and healthy ageing for the vast majority of people.

Saffron (Crocus sativus L.) is a medicinal plant, originally cultivated in the East and Middle East, and later in some Mediterranean countries. Saffron is obtained from the stigmas of the plant. Currently, the use of saffron is undergoing a revival. The medicinal virtues of saffron, its culinary use and its high added value have led to the clarification of its phytochemical profile and its biological and therapeutic characteristics. Saffron is rich in carotenoids and terpenes. The major products of saffron are crocins and crocetin (carotenoids) deriving from zeaxanthin, pirocrocin and safranal, which give it its taste and aroma, respectively. Saffron and its major compounds have powerful antioxidant and anti-inflammatory properties in vitro and in vivo. Anti-tumor properties have also been described. The goal of this review is to present the beneficial effects of saffron and its main constituent molecules on neuropsychiatric diseases (depression, anxiety and schizophrenia) as well as on the most frequent age-related diseases (cardiovascular, ocular and neurodegenerative diseases, as well as sarcopenia). Overall, the phytochemical profile of saffron confers many beneficial virtues on human health and, in particular, on the prevention of age-related diseases, which is a major asset reinforcing the interest for this medicinal plant.

Aging is characterized by a progressive increase in oxidative stress, which favors lipid peroxidation and the formation of cholesterol oxide derivatives, including 7β-hydroxycholesterol (7β-OHC). This oxysterol, which is known to trigger oxidative stress, inflammation, and cell death, could contribute to the aging process and age-related diseases, such as sarcopenia. Identifying molecules or mixtures of molecules preventing the toxicity of 7β-OHC is therefore an important issue. This study consists of determining the chemical composition of Tunisian Pistacia lentiscus L. seed oil (PLSO) used in the Tunisian diet and evaluating its ability to counteract the cytotoxic effects induced by 7β-OHC in murine C2C12 myoblasts. The effects of 7β-OHC (50 µM; 24 h), associated or not with PLSO, were studied on cell viability, oxidative stress, and on mitochondrial and peroxisomal damages induction. α-Tocopherol (400 µM) was used as the positive control for cytoprotection. Our data show that PLSO is rich in bioactive compounds; it contains polyunsaturated fatty acids, and several nutrients with antioxidant properties: phytosterols, α-tocopherol, carotenoids, flavonoids, and phenolic compounds. When associated with PLSO (100 µg/mL), the 7β-OHC-induced cytotoxic effects were strongly attenuated. The cytoprotection was in the range of those observed with α-tocopherol. This cytoprotective effect was characterized by prevention of cell death and organelle dysfunction (restoration of cell adhesion, cell viability, and plasma membrane integrity; prevention of mitochondrial and peroxisomal damage) and attenuation of oxidative stress (reduction in reactive oxygen species overproduction in whole cells and at the mitochondrial level; decrease in lipid and protein oxidation products formation; and normalization of antioxidant enzyme activities: glutathione peroxidase (GPx) and superoxide dismutase (SOD)). These results provide evidence that PLSO has similar antioxidant properties than α-tocopherol used at high concentration and contains a mixture of molecules capable to attenuate 7β-OHC-induced cytotoxic effects in C2C12 myoblasts. These data reinforce the interest in edible oils associated with the Mediterranean diet, such as PLSO, in the prevention of age-related diseases, such as sarcopenia.

Neurodegenerative diseases represent a major public health issue and require better therapeutic management. The treatments developed mainly target neuronal activity. However, an inflammatory component must be considered, and microglia may constitute an important therapeutic target. Given the difficulty in developing molecules that can cross the blood–brain barrier, the use of food-derived molecules may be an interesting therapeutic avenue. Docosahexaenoic acid (DHA), an omega-3 polyunsaturated fatty acid (22:6 omega-3), has an inhibitory action on cell death and oxidative stress induced in the microglia. It also acts on the inflammatory activity of microglia. These data obtained in vitro or on animal models are corroborated by clinical trials showing a protective effect of DHA. Whereas DHA crosses the blood–brain barrier, nutritional intake lacks specificity at both the tissue and cellular level. Nanomedicine offers new tools which favor the delivery of DHA at the cerebral level, especially in microglial cells. Because of the biological activities of DHA and the associated nanotargeting techniques, DHA represents a therapeutic molecule of interest for the treatment of neurodegenerative diseases.

Oxysterols are assumed to be the driving force behind numerous neurodegenerative diseases. In this work, we aimed to study the ability of 7β-hydroxycholesterol (7β-OHC) to trigger oxidative stress and cell death in human neuroblastoma cells (SH-SY5Y) then the capacity of Nigella sativa and Milk thistle seed oils (NSO and MTSO, respectively) to oppose 7β-OHC-induced side effects. The impact of 7β-OHC, associated or not with NSO or MTSO, was studied on different criteria: cell viability; redox status, and apoptosis. Oxidative stress was assessed through the intracellular reactive oxygen species (ROS) production, levels of enzymatic and non-enzymatic antioxidants, lipid, and protein oxidation products. Our results indicate that 7β-OHC (40 µg/mL) exhibit pr-oxidative and pro-apoptotic activities shown by a decrease of the antioxidant enzymatic activities and an increase of ROS production, lipid, and protein oxidation end products as well as nitrotyrosine formation and caspase 3 activation. However, under the pre-treatment with NSO, and especially with MTSO (100 µg/mL), a marked attenuation of oxidative damages was observed. Our study suggests harmful effects of 7β-OHC consisting of pro-oxidative, anti-proliferative, and pro-apoptotic activities that may contribute to neurodegeneration. NSO and especially MTSO showed potential cytoprotection against the cytotoxicity of 7β-OHC.