Antioxidant and Anti-inflammatory Properties of Algerian Thymelaea microphylla Coss. and Dur. Extracts

In Vitro Protective Effects of a Standardized Extract From Cynara Cardunculus L. Leaves Against TNF-α-Induced Intestinal Inflammation

Inflammatory bowel disease (IBD) represents a group of progressive disorders characterized by recurrent chronic inflammation of the gut. New unconventional therapies based on plant derived compounds capable of preventing and/or reducing acute or chronic inflammation could represent a valid alternative for the treatment or prevention of IBDs. Cynara cardunculus L. leaves, considered a food-waste suitable as a rich source of bioactive polyphenols including luteolin and chlorogenic acid, has been reported for its positive effects in digestive tract. The aim of the present work was to evaluate the in vitro molecular mechanisms of beneficial effects of a standardized polyphenol-rich extract obtained from the leaves of Cynara cardunculus L (CCLE) against acute intestinal inflammation induced by TNF-α on intestinal epithelial Caco-2 cells. CCLE prevented TNF-α-induced NF-κB inflammatory pathway and the overexpression of IL-8 and COX-2. In addition, CCLE was able to improve basal intracellular antioxidant power in both TNF-α-unexposed or -exposed Caco-2 cells and this effect was associated to the activation of Nrf2 pathway, a master regulator of redox homeostasis affecting antioxidant and phase II detoxifying genes, stimulating an adaptive cellular response. In conclusion, our data clearly evidenced that, although considered a waste, Cynara cardunculus leaves may be used to obtain extracts rich in bioactive polyphenols potentially useful for prevention and treatment of inflammatory intestinal diseases.

Antioxidant and antiaging effect of traditional Thai rejuvenation medicines in Caenorhabditis elegans

OBJECTIVE

This study explored the rejuvenation mechanisms of Thai polyherbal medicines using different approaches, including in vitro methods, as well as a well-defined nematode model, Caenorhabditis elegans.

METHODS

THP-R-SR012 decoction was selected from 23 polyherbal medicines, based on metal-chelating and chain-breaking antioxidant capacities. The influences of this extract on the survival and some stress biomarkers of C. elegans under paraquat-induced oxidative stress were evaluated. Furthermore, lifespan analysis and levels of lipofuscin accumulation were examined in senescent nematodes. The phytochemical profile of THP-R-SR012 was analyzed.

RESULTS

Supplementation with THP-R-SR012 decoction significantly increased the mean lifespan and reduced the oxidative damage to C. elegans under oxidative stress conditions. Further, THP-R-SR012 supplementation slightly influenced the lifespan and the level of lipofuscin accumulation during adulthood. Antioxidant-related phytochemical constituents of THP-R-SR012 decoction were rutin, naringenin, 3,4-dihydroxybenzoic acid, gallic acid, glycyrrhizic acid, demethoxycurcumin and 18α-glycyrrhetinic acid.

CONCLUSION

The antioxidant potential of THP-R-SR012 was due to its scavenging properties, its enhancement of antioxidant-related enzyme activities, and the presence of the antioxidant-related compound. These results support the traditional use of THP-R-SR012 decoction as a tonic for nourishing and strengthening the whole body.

Nutraceuticals for prevention of atherosclerosis: Targeting monocyte infiltration to the vascular endothelium

Cardiovascular disease (CVD) is the leading cause of death, globally, and is a serious problem in developing countries. Preventing atherosclerosis is key to reducing the risk of developing CVD. Similar to carcinogenesis, atherogenesis can be divided into four stages: initiation, promotion, progression, and acute events. The current study focuses on the promotion stage, which is characterized by circular monocyte penetration into vascular endothelial cells, monocyte differentiation into macrophages, and the formation of foam cells. This early stage of atherogenesis is a major target for nutraceuticals. We discuss nutraceuticals that can potentially inhibit monocyte adhesion to the vascular endothelium, thereby preventing the promotional stage of atherosclerosis. The mechanisms through which these nutraceuticals prevent monocyte adhesion are classified according to the following targets: NF-κB, ROS, MAPKs, and AP-1. Additionally, we discuss promising targets for nutraceuticals that can regulate monocyte adhesion to the endothelium. PRACTICAL APPLICATIONS: Introduction of atherogenesis with initiation, promotion, progression, and acute events provide specific information and factors for each step in the development of atherosclerosis. Functional food or pharmaceutical researchers can set target stages and use them to develop materials that control atherosclerosis. In particular, because it focuses on vascular inflammation via interaction between monocytes and vascular endothelial cells, it provides specific information to researchers developing functional foods that regulate this process. Therefore, this manuscript, unlike previous papers, will provide material information and potential mechanisms of action to researchers who want to develop functional foods that control vascular inflammation rather than vascular lipids.

Yields, chemical composition, and antimicrobial activity of two Algerian essential oils against 40 avian multidrug-resistant Escherichia coli strains

AIM

The aim of this study is to investigate, in vitro, a possible antibacterial activity of Algerian essential oils (EOs) of Thyme (Thymus vulgaris L.) and that of Coriander (Coriandrum sativum L.) against multidrug-resistant avian Escherichia coli strains and this in a perspective of their future use as a substitute for antibiotics (ATBs).

MATERIALS AND METHODS

In addition to the reference strain of E. coli ATCC 25922, 40 strains of avian E. coli have been isolated (24 strains of broilers and 16 of turkeys), their antimicrobial resistance profile was determined by antibiogram tests against 21 ATBs whereupon they were subjected to the action of two Algerian EOs; the EO of Thyme (T. vulgaris L.) and that of Coriander (C. sativum L.), which oils were extracted by hydrodistillation and analyzed by Gas Chromatography coupled to Mass Spectrometry (GC-MS) and this for the determination of their chemical composition. The antibacterial activity, resulting in zones of inhibition, was evaluated by carrying out, in triplicate, aromatograms for both pure EO and that which has been diluted to 15% in Dimethyl Sulfoxide (DMSO), while the minimum inhibitory concentrations (MIC) of the two EOs were highlighted by the method of liquid macrodilution.

RESULTS

Antibiogram performance demonstrated an alarming state of antimicrobial resistance, the multidrug resistance rate was estimated at 100% for the broilers chicken strains and at 81.25% for strains isolated from turkeys, hydrodistillation allowed to obtained EOs with yields estimated at 1.22±0.26% for Thyme EO and 0.23±0.15% for the essence of Coriander, the GC-MS analysis identified 19 main compounds and showed that the majority chemical components were Carvacrol (73.03%) for Thyme volatile oil and Linalool (60.91%) for Coriander EO, aromatograms and the determination of MIC concluded that the EO of Thyme showed a greater antibacterial activity with an average of the zones of inhibition estimated at 26.75±0.426 mm and MIC ranging from 0.07 to 0.93 mg/ml against an average of the inhibition zones evaluated at 17.05±0.383 mm and MICs evaluated between 0.6 and 10 mg/ml for the EO of Coriander.

CONCLUSION

In aviculture, these results seem to be very promising in the case where we think about the replacement of ATBs by EOs, in vivo studies would be very interesting to confirm or invalidate this hypothesis.

Phytochemical profiles, phototoxic and antioxidant properties of eleven Hypericum species - A comparative study

Hypericum is one out of the nine genera belonging to the botanical family Clusiaceae Lindl (syn. Hypericaceae Juss.; APG III, 2009). The genus contains 484 species spread worldwide, one of which, Hypericum perforatum, is largely used in folk medicine. The aim of this study was to evaluate the chemical composition, along with the antioxidant and phototoxic activity, of 11 Hypericum species grown in Sicily (H. perforatum L., H. aegypticum L., H. androsaemum L., H. calycinum L., H. hircinum L., H. hirsutum L., H. montanum L., H. patulum Thunb., H. perfoliatum L., H. pubescens Boiss., H. tetrapterum Fr.). Samples of flowering tops collected from these Hypericum species were extracted and analysed by high performance liquid chromatography with diode-array detection and mass spectrometry (HPLC-DAD-MS) to determine their content of main polyphenols, acylphloroglucinols, and naphthodianthrones. The extracts were also subjected to a photocytotoxic assay using murine fibroblast (NIH/3T3), and their antioxidant activity evaluated by means of Folin-Ciocalteau, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, and oxygen radical antioxidant capacity assays. Phytochemical analysis allowed us to identify and quantify 20 metabolites, each of them possessing a well-known biological activity. Furthermore, all examined species showed a good cytotoxic and antioxidant/radical scavenging activity. These results indicate that in addition to the well-known H. perforatum, at least other three species (H. tetrapterum, H. pubescens, and H. montanum) represent potential sources of biologically active compounds, and at least other two species (H. perfoliatum and H. tetrapterum), due to their phototoxicity are candidates for application in photodynamic therapy.

Bioactivity and Toxicity of Senna cana and Senna pendula Extracts

This work investigated the content of total polyphenolic compounds and flavonoids as well as their toxicity and larvicidal and acetylcholinesterase inhibitory activities. The antioxidant activities of two medicinal Senna species extracts (Senna cana and Senna pendula) were also investigated. The ethanol extract of the leaves of S. cana and the ethanol extract of the branches of S. pendula presented the best performance in the DPPH/FRAP and ABTS/ORAC assays, respectively. For the inhibition of acetylcholinesterase, the hexane extract of the flowers of S. pendula presented the lowest IC₅₀ value among the ethanol extracts of the leaves of S. cana and showed the best performance in some assays. The hexane extract of the leaves of S. pendula and the hexane extract of the branches of S. cana were moderate to Artemia salina Leach. In the quantification of phenols and flavonoids, the ethanol extract of the leaves of S. cana presented the best results. The ethanol extracts of the leaves of S. cana were found to be rich in antioxidants, phenolic compounds, and flavonoids. These results indicate the antioxidant potential of the extracts of Senna species and can be responsible for some of the therapeutic uses of these plants.

Flavonoid profile, antioxidant and antiglycation properties of Retama sphaerocarpa fruits extracts

Retama sphaerocarpa occurs in the Mediterranean area of North-east Africa and in the Iberian Peninsula, and grows on a variety of soil types and climatic conditions. Used in Algerian folk medicine, it is a valuable species for revegetation and soil restoration. The aim of this study is to evaluate flavonoid composition and antioxidant and antiglycation properties of methanolic and aqueous extracts from R. sphaerocarpa fruits. HPLC-PDA/ESI-MS was used to identify/quantify flavonoid content. Antioxidant activity was evaluated by Folin-Ciocalteu, ORAC, FRAP, TEAC, and DPPH assays, and antiglycation capability by glucose/fructose-BSA assay. Results showed that fruits contain isoflavones (daidzein and genistein derivatives) and flavonols (apigenin, isorhamnetin, kaempferol and quercetin derivatives), and extracts (especially the methanolic one, richer in flavonoids) possess good in vitro antioxidant and antiglycation properties. These findings evidence that R. sphaerocarpa fruits are a source of valuable phytochemicals, with potential applications in the field of phytopharmaceuticals and in food industry.

Cyanidin-3-O-Glucoside Modulates the In Vitro Inflammatory Crosstalk between Intestinal Epithelial and Endothelial Cells

Intestinal epithelium represents a protective physical barrier and actively contributes to the mucosal immune system. Polarized basolateral intestinal secretion of inflammatory mediators, followed by activation of NF-κB signaling and inflammatory pathways in endothelial cells, efficiently triggers extravasation of neutrophils from the vasculature, therefore contributing to the development and maintenance of intestinal inflammation. Proper regulation of NF-κB activation at the epithelial interface is crucial for the maintenance of physiological tissue homeostasis. Many papers reported that anthocyanins, a group of compounds belonging to flavonoids, possess anti-inflammatory effects and modulate NF-κB activity. In this study, by using a coculture in vitro system, we aimed to evaluate the effects of TNF-α-stimulated intestinal cells on endothelial cells activation, as well as the protective effects of cyanidin-3-glucoside (C3G). In this model, TNF-α induced nuclear translocation of NF-κB and TNF-α and IL-8 gene expression in Caco-2 cells, whereas C3G pretreatment dose-dependently reduced these effects. Furthermore, TNF-α-stimulated Caco-2 cells induced endothelial cells activation with increased E-selectin and VCAM-1 mRNA, leukocyte adhesion, and NF-κB levels in HUVECs, which were inhibited by C3G. We demonstrated that selective inhibition of the NF-κB pathway in epithelial cells represents the main mechanism by which C3G exerts these protective effects. Thus, anthocyanins could contribute to the management of chronic gut inflammatory diseases.

Cyanidin-3-O-glucoside inhibits NF-kB signalling in intestinal epithelial cells exposed to TNF-α and exerts protective effects via Nrf2 pathway activation

Chronic intestinal inflammatory disorders, such as Inflammatory Bowel Diseases (IBDs), are characterized by excessive release of proinflammatory mediators, intestinal barrier dysfunction and excessive activation of NF-kB cascade. Previous studies shown that TNF-α plays a central role in intestinal inflammation of IBDs and supported beneficial effects of flavonoids against chronic inflammatory diseases. In this study, we employed an in vitro model of acute intestinal inflammation using intestinal Caco-2 cells exposed to TNF-α. The protective effects of cyanidin-3-glucoside (C3G), an anthocyanin widely distributed in mediterranean diet, were then evaluated. Caco-2 cells exposure to TNF-α activated NF-kB proinflammatory pathway and induced IL6 and COX-2 expression. Cells pretreatment for 24h with C3G (20-40μM) prevented TNF-α-induced changes, and improved intracellular redox status. Our results demonstrated that C3G, also without any kind of stimulus, increased the translocation of the transcription factor Nrf2 into the nucleus so activating antioxidant and detoxifying genes. In conclusion, C3G exhibited protective effects through the inhibition of NF-kB signalling in Caco-2 cells and these beneficial effects appear to be due to its ability to activate cellular protective responses modulated by Nrf2. These data suggest that anthocyanins could contribute, as complementary or preventive approaches, to the management of chronic inflammatory diseases.