► Rosemary extract shows strong antilisterial activity. ► Olive oil and cocoa phenolic extracts show lower antilisterial activity. ► Antilisterial effect of extracts is superior to the effect of ...their main phenolics. ► The antioxidant capacities are as follows: rosemary
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cocoa
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olive oil. ► Additive/synergistic effect could exist between polyphenols present in extracts.
Antibacterial and antioxidant activity of polyphenols from olive oil, cocoa, and rosemary extract was tested. Antimicrobial activity against
Listeria strains was assessed using broth dilution and time-kill curve methods. The 2,2-diphenyl-2-picrylhydracyl hydrate (DPPH) radical scavenging method, Folin–Ciocalteu method, and high performance liquid chromatography (HPLC) were used for phenolics identification and determination of antioxidants level. Antibacterial and antioxidant activity of main pure phenolic compounds, such as hydroxytyrosol in olive oil, epicatechin in cocoa and carnosic acid in rosemary was each compared with their extracts.
Rosemary extract showed strong, while olive oil and particularly cocoa phenolic extract showed lower antilisterial activity. The overall relative antioxidant capacities of the samples were as follows in decreasing order: rosemary
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cocoa
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olive oil. These results indicate that rosemary, olive oil, and cocoa polyphenols could be potentially used as alternative food additives for the prevention of food spoilage, and contamination with
Listeria monocytogenes.
Market interest in aromatic plants from the Mediterranean is continuously growing mainly due to their medicinal and bioactive compounds (BACs) with other valuable constituents from essential oils ...(EOs). From ancient times, these plants have been important condiments for traditional Mediterranean cuisine and remedies in folk medicine. Nowadays, they are considered as important factors for food quality and safety, due to prevention of various deteriorative factors like oxidations and microbial spoilage. EOs have different therapeutic benefits (e.g. antioxidant, anti-inflammatory, antimicrobial, and antifungal), while BACs mostly affect nutritive, chemical, microbiological, and sensory quality of foods. Currently, many plant extracts are used for functional (healthy) foods, which additionally fuels consumer and industrial interest in sustainable and non-toxic routes for their production. EO yields from dried plants are below 5%. Their extraction is strongly dependent on the hydrophobic or lipophilic character of target molecules, hence the common use of organic solvents. Similarly, BACs encompass a wide range of substances with varying structures as reflected by their different physical/chemical qualities. Thus, there is a need to identify optimal non-toxic extraction method(s) for isolation/separation of EO/BCs from plants. Various innovative non-thermal extractions (e.g. ultrasound-, high-pressure-, pulsed electric fields assisted extraction, etc.) have been proposed to overcome the above mentioned limitations. These techniques are “green” in concept, as they are shorter, avoid toxic chemicals, and are able to improve extract yields and quality with reduced consumption of energy and solvents. This research provides an overview of such extractions of both BAC and EOs from Mediterranean herbs, sustained by innovative and non-conventional energy sources.
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•Green extraction of bioactive compounds and essential oils from Mediterranean herbs.•Innovative non-thermal vs. conventional extraction techniques.•E3 principle of innovative non-thermal techniques.•The potential of Mediterranean herbs in food industry application.
Osteoporosis is a skeletal disease of bone mass loss and deterioration of the bone structure leading to increased susceptibility to fracture, generally associated with risk factors that include ...hormonal imbalance, increased oxidative stress and chronic inflammation.
Nutritional factors and certain lifestyle reduce the risks of occurrence of osteoporosis and are part of a number of national and international prevention recommendations. Recent reports based on molecular mechanisms of dietary polyphenols have highlighted the benefits in their prevention and treatment of osteoporosis. Polyphenols can protect bone health through reduction of oxidative stress because they act as antioxidants, reduction of inflammation by proinflammatory signaling, modulation of osteoblastogenesis, osteoclastogenesis, and osteoimmunological action.
This review reports about some important bioactive polyphenol sources and describes their action against osteoporosis based on in vitro and in vivo studies.
•Dietary polyphenols (DPs) reduce bone loss through antioxidative and anti-inflammatory actions.•DPs reduce oxidative stress, enhancing osteoblastogenesis and suppressing osteoclastogenesis.•DPs improve bone structure by regulation of different molecular signaling.•Fruit and vegetables rich in polyphenols may be used as an effective remedy in the prevention and treatment of osteoporosis.
The ultrasound-assisted extraction (UAE) of oleuropein (OLE), verbascoside (VER), and luteolin-4'-
-glucoside (L4OG), as the major phenolics from olive leaves, was optimized using response surface ...methodology (RSM). A Box⁻Behnken design (BBD) was used to monitor the effect of different modes of ultrasound operation (pulsed and continuous), liquid⁻solid (L⁻S) ratio, and sonication time on each phenolic yield. The yield of UAE and conventional solid extraction (CSE) was determined after performing ultrahigh-performance liquid chromatography with a diode-array detector (UHPLC-DAD) analysis on the extracts. The results suggested that, under optimal conditions, the concentrations of OLE, VER, and L4OG were 13.386, 0.363, and 0.527 mg/g of dry powdered olive leaves (DPOL), respectively. Verification of experiments was carried out under the modified optimal conditions and the relative errors between the predicted and experimental values were dependent on the examined phenolic compound (OLE 8.63%, VER 11.3%, and L4OG 22.48%). In comparison with CSE, UAE improved the yields of OLE, VER, and L4OG (32.6%, 41.8%, and 47.5%, respectively, after 1 min) at a temperature of 60 °C, an L⁻S ratio of 15 (
), and in the continuous mode of UAE. We demonstrated that the UAE technique is an efficient method for enhancing yields of OLE, VER, and L4OG in olive-leaf extracts, while the chosen model was adequate to optimize the extraction of major phenolic compounds from olive leaves.
Skeletal muscles are high-insulin tissues responsible for disposing of glucose via the highly regulated process of facilitated glucose transporter 4 (GLUT4). Impaired insulin action in diabetes, as ...well as disorders of GLUT4 vesicle trafficking in the muscle, are involved in defects in insulin-stimulated GLUT4 translocation. Since the Rab GTPases are the main regulators of vesicular membrane transport in exo- and endo-cytosis, in the present work, we studied the effect of olive leaf polyphenols (OLPs) on Rab8A, Rab13, and Rab14 proteins of the rat soleus muscle in a model of streptozotocin (SZT)-induced diabetes (DM) in a dose-dependent manner. Glucose, cholesterol, and triglyceride levels were determined in the blood, morphological changes of the muscle tissue were captured by hematoxylin and eosin histological staining, and expression of GLUT4, Rab8A, Rab13, and Rab14 proteins were analyzed in the rat soleus muscle by the immunofluorescence staining and immunoblotting. OLPs significantly reduced blood glucose level in all treated groups. Furthermore, significantly reduced blood triglycerides were found in the groups with the lowest and highest OLPs treatment. The dynamics of activation of Rab8A, Rab13, and Rab14 was OLPs dose-dependent and more effective at higher OLP doses. Thus, these results indicate a beneficial role of phenolic compounds from the olive leaf in the regulation of glucose homeostasis in the skeletal muscle.
•Cocoa polyphenols (CPs) suppressed hepatotoxicity and inflammation in CCl4-intoxicated mice.•Cocoa extract (CE) and epicatechin (EC) improved glucose metabolism after imbalance induced by CCl4 ...intoxication.•CPs are involved in the early stage of antifibrotic and anticarcinogenic effects in the liver.•CPs affected beneficial regulation of subcellular redox state caused by CCl4 intoxication.
The therapeutic effects of cocoa polyphenols on acute carbon tetrachloride (CCl4)-intoxicated mice were investigated. After determining polyphenols profile in the cocoa extract (CE), CE at a dose of 34.5 mg/kg and epicatechin (EC) at a dose of 2.24 mg/kg were intraperitoneally (i.p.) administered to BALB/cN mice following CCl4 treatment. CE and EC post-treatments suppressed hepatotoxicity and inflammation, ameliorated serum markers of liver injury, returned blood lactate and glucose levels to normal, stimulated synthesis and storage of liver glycogen, and modulated glucose metabolism imbalance induced by CCl4. Cocoa polyphenols also exhibited early stage antifibrotic and anticarcinogenic effects. They affected beneficially the mitochondrial functionality acting on dysfunction in mitochondrial respiration caused by CCl4 and antioxidants regulation at subcellular levels.
The aim of this study was the monitoring of the chemical composition of olive oil at different ripening stages to determine the appropriate harvesting time during any given crop season in the ...northern Adriatic region. For this purpose, from September to November, two Croatian olive cultivars (Drobnica and Buza) were taken from two different olive orchards and for the respective olive oils, prepared on a laboratory scale, the major saponifiable, unsaponifiable and phenolic compounds were determined. Based on the chemical analyses performed, the optimal harvesting time has been set in October for both cultivars. Buza had a higher oleic acid, but lower total sterols, squalene and total alkanols. Compared to the local cultivars, the studied cultivars had a high total phenolic content and antioxidant activity. The antioxidant activity and concentrations of total phenols correlated with α-tocopherol in oil samples taken during the ripening progress. Finally, trace minerals detected in Buza and Drobnica oil differed, which can be an indicator of oxidative stability and authenticity of oils.
Olive leaves are the richest source of phenolic compounds, particularly oleuropein, which has many beneficial effects on human health. This study compares the effect of three extraction techniques: ...ultrasonic-solvent extraction, microwave-assisted extraction, and supercritical CO2 extraction of freeze-dried wild olive leaves (Olea europea subps. oleaster, Hoffmanns. & Link) on oleuropein concentration in obtained extracts. The extract with the highest concentration of oleuropein was obtained after low-frequency ultrasound solvent extraction (WOLE-S) (71.97 µg/mL). Oleuropein from that extract showed low stability after simulated gastric digestion with human gastric juices (35.66%) and high stability after 60 min of intestinal phase (65.97%). The highest antiproliferative activity of WOLE-S and pure oleuropein was detected against T24 cancer cells. The antiproliferative activity of WOLE-S against MD-MBA-123, A549, and A1235 cells was moderate, while the activity of oleuropein was high. WOLE-S significantly down-regulated the expression of IL-6 in A549 cells, indicating a possible anti-inflammatory effect in lung cancer cells. The expression of IL-8 was slightly reduced by treating the cells with WOLE-S, while the expression of IL-10 was not altered by the treatment with WOLE-S or oleuropein.
•The antioxidant potential of Terminalia bellerica aerial parts extracts was determined.•T. bellerica ethyl acetate (TBE) extract had the highest phenolic/flavonoid content.•TBE ameliorated hepatic ...oxidative stress by reducing 4-HNE and 3-NT expression.•TBE reduced liver inflammation by ameliorating NF-κB, COX-2 and TNF-α expression.•Hepatic fibrogenesis evaluated by TGF-β1 and α-SMA expression was suppressed by TBE.
The hepatoprotective activity of Terminalia bellerica aerial parts was evaluated in chemically induced murine toxicity model. The antioxidant potential of methanol, ethyl acetate, diethyl ether, petroleum ether and chloroform extract was determined in vitro. The most potent, T. bellerica ethyl acetate extract (TBE), was administered to BALB/cN mice in doses of 100 and 300 mg/kg by oral gavage, once daily for 2 consecutive days following carbon tetrachloride (CCl4)-intoxication. TBE significantly ameliorated hepatic necrosis, which coincided with decreased expression of oxidative stress biomarkers, 4-hydroxynonenal (4-HNE) and 3-nitrotyrosine (3-NT), and restored P450 2E1 (CYP2E1) expression. TBE also reduced nuclear factor-kappaB (NF-κB), cyclooxygenase-2 (COX-2) and tumour necrosis factor-alpha (TNF-α) overexpression in injured livers, indicating amelioration of inflammatory response. Additionally, hepatic fibrosis, evidenced by transforming growth factor-beta1 (TGF-β1) and alpha-smooth muscle actin (α-SMA) expression, was significantly suppressed. The results of the current study suggest a significant hepatoprotective activity of TBE, which was comparable with silymarin.
The natural phytochemicals present in foods, including anthocyanins, might play a role in attenuating obesity by producing a decrease in weight and adipose tissue. This review focused on current ...knowledge about anthocyanins’ role in obesity and its related comorbidities reported in animal models and humans. We summarized their target identification and mechanism of action through several pathways and their final effects on health and well-being. Into consideration of ongoing researches, we highlighted the following key points: a healthy relationship between anthocyanin supplementation and antiobesity effects suffers of the same pros and cons evidenced when the beneficial responses to other phytochemical treatments towards different degenerative diseases have been considered; the different dosage applied in animal versus clinical studies; the complex metabolism and biotransformation to which anthocyanins and phytochemicals are subjected in the intestine and tissues; the possibility that different components present in the supplemented mixtures can interact generating antagonistic, synergistic, or additive effects difficult to predict, and the difference between prevention and therapy. The evolution of the field must seriously consider the need to establish new and adequate cellular and animal models which may, in turn, allow the design of more efficient and prevention-targeted clinical studies.
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