Antiradical activity of gallic acid included in lipid interphases

Antibacterial and Antihemolytic Activity of New Biomaterial Based on Glycyrrhizic Acid and Quercetin (GAQ) against Staphylococcus aureus

The goal of this study is to obtain and characterize the complex of quercetin with glycyrrhizic acid, which is known to serve as a drug delivery system. Quercetin is a flavonoid with a wide range of biological activities, including an antimicrobial effect. However, quercetin instability and low bioavailability that limits its use in medical practice makes it necessary to look for new nanoformulations of it. The formation of the GAQ complex (2:1) was confirmed by using UV and FT-IR spectroscopies. It was found that the GAQ exhibited antimicrobial and antihemolytical activities against S. aureus bacteria and its main virulent factor-α-hemolysin. The IC₅₀ value for the antihemolytical effect of GAQ was 1.923 ± 0.255 µg/mL. Using a fluorescence method, we also showed that the GAQ bound tightly to the toxin that appears to underlie its antihemolytic activity. In addition, another mechanism of the antihemolytic activity of the GAQ against α-hemolysin was shown, namely, its ability to increase the rigidity of the outer layer of the erythrocyte membrane and thus inhibit the incorporation of α-hemolysin into the target cells, increasing their resistance to the toxin. Both of these effects of GAQ were observed at concentrations below the MIC value for S. aureus growth, indicating the potential of the complex as an antivirulence agent.

In vitro bioactivities and preparation of nanoemulsion from coconut oil loaded Curcuma aromatica extracts for cosmeceutical delivery systems

Curcuma aromatica (CA) is a herbaceous plant in the Zingiberaceae family. It has antioxidative activity and anti-inflammatory properties. The purpose of this study was to investigate the effect of solvents and extraction methods on CA rhizomes. The crude extracts were tested for phenolic and flavonoid contents, antioxidative activity by DPPH and lipid peroxidation assay, and protein denaturation inhibition. The crude extracts with 95% ethanol by maceration technique showed good results. It had phenolic content at 99.28 ± 1.09 mg GAE/g extract, flavonoid content at 397.00 ± 27.54 mg QE/g extract, antioxidative activity by DPPH assay and lipid peroxidation assay at IC₅₀ value of 0.55 ± 0.02 mg/ml and 0.60 ± 0.10 mg/ml, respectively. The percentage of protein denaturation inhibition was 65.97 ± 4.68%. The crude extract with 95% ethanol by maceration technique was selected to formulate nanoemulsion. Nanoemulsion formulation consisted of DI water, Tween 80, CA extract, coconut oil and Span 80 at 72.50, 12.93, 7.07, 5.00 and 2.5%w/w, respectively. Its appearance was an opaque yellow liquid with no precipitation and no phase separation at room temperature. The particle size, pH, and viscosity were 70.20 ± 0.38 nm, 5.87 ± 0.01 and 3.56 ± 0.24 cP, respectively. Nanoemulsion loaded CA extract had bioactivities and highly stable characteristics after heating–cooling test for 6 cycles. This study has demonstrated the potential of nanoemulsion from coconut oil loaded CA extract for further development to novel cosmetic products.

Phenolic Compounds Impact on Rheumatoid Arthritis, Inflammatory Bowel Disease and Microbiota Modulation

Non-communicable chronic diseases (NCDs) are nowadays the principal cause of death, especially in most industrialized nations. These illnesses have increased exponentially with the consumption of diets very high in fat and sugar, not to mention stress and physical inactivity among other factors. The potential impact of suboptimal diets on NCDs’ morbidity and mortality rates brings to the forefront the necessity for a new way of improving dietary habits. The literature provides extensive scientific work that presents evidence that phenolic compounds from diets have antioxidant, anti-inflammatory and antiproliferative activities that impact human health. Gut microbiota modulation by some phenolic compounds leads to favorable changes in abundance, diversity, and in the immune system. However, polyphenol’s limited bioavailability needs to be overcome, highlighting their application in new delivery systems and providing their health benefits in well-established ways such as health maintenance, treatment or adjuvant to conventional pharmacological treatments. In this context, novel dietary approaches, including new food supplements, have emerged to prevent diseases and preserve health.

Interaction of chlorogenic acid with model lipid membranes and its influence on antiradical activity

Chlorogenic acid (CGA) is a strong phenolic antioxidant with antibacterial properties composed by a caffeoyl ester of quinic acid. Although a number of benefits has been reported and related to interactions with the red blood cell membranes, details on its membrane action and how composition and membrane state may affect it, is not yet well defined. In this work, the interaction of CGA with lipid monolayers and bilayers composed by 1,2-dimiristoyl-sn-glycero-3-phosphocholine (DMPC); 1,2-di-O-tetradecyl-sn-glycero-3-phosphocholine (14:0 diether PC); 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) and 1,2-di-O-hexadecyl-sn-glycero-3-phosphocholine (16:0 diether PC) were studied at different surface pressures (π). The kinetics of interaction was found to be more rapid in DMPC than in the absence of carbonyl groups. Measurements by FTIR-ATR at different water activities confirm specific interactions of CGA with carbonyl and phosphate groups affecting water level along hydrocarbon region. The antioxidant activity of CGA in the presence of DMPC unilamellar vesicles, evidenced by the absorbance reduction of the radical cation ABTS^•+, is significantly different with respect to aqueous solution. The influence of CGA on antiradical activity (ARA) with lipid membranes depending on the hydration state of the lipid interface is discussed.

Interactions of dietary polyphenols with epithelial lipids: advances from membrane and cell models in the study of polyphenol absorption, transport and delivery to the epithelium

Currently, diet-related diseases such as diabetes, obesity, hypertension, and cardiovascular diseases account for 70% of all global deaths. To counteract the rising prevalence of non-communicable diseases governments are investing in persuasive educational campaigns toward the ingestion of fresh fruits and vegetables. The intake of dietary polyphenols abundant in Mediterranean and Nordic-type diets holds great potential as nutritional strategies in the management of diet-related diseases. However, the successful implementation of healthy nutritional strategies relies on a pleasant sensory perception in the mouth able to persuade consumers to adopt polyphenol-rich diets and on a deeper understanding on the chemical modifications, that affect not only their chemical properties but also their physical interaction with epithelial lipids and in turn their permeability, location within the lipid bilayer, toxicity and biological activity, and fate during absorption at the gastro-intestinal epithelium, transport in circulation and delivery to the endothelium. In this paper, we review the current knowledge on the interactions between polyphenols and their metabolites with membrane lipids in artificial membranes and epithelial cell models (oral, stomach, gut and endothelium) and the findings from polyphenol-lipid interactions to physiological processes such as oral taste perception, gastrointestinal absorption and endothelial health. Finally, we discuss the limitations and challenges associated with the current experimental approaches in membrane and cell model studies and the potential of polyphenol-rich diets in the quest for personalized nutritional strategies ("personalized nutrition") to assist in the prevention, treatment, and management of non-communicable diseases in an increasingly aged population.

Phytosomes with Persimmon (Diospyros kaki L.) Extract: Preparation and Preliminary Demonstration of In Vivo Tolerability

Persimmon (Diospyros kaki L.), a fruit rich in phenolic compounds (PCs), has been considered effective in mitigating oxidative damage induced by an excess of reactive oxygen species. Due to large molecular weight and intrinsic instability in some physiological fluids, PCs’ passage through biological membranes is very limited. Carriers like phytosomes are promising systems to optimize oral absorption of encapsulated extracts. This work prepared and fully characterized phytosomes containing bioactive phenolic extracts from persimmon in terms of size, surface charge, encapsulation efficiency and stability over six months. These phytosomes were orally dosed to Wistar rats during a 15-day period. Afterwards, haematological and biochemical analyses were performed. Monodisperse phytosomes were successfully prepared, with size less than 300nm (PI < 0.3) and high encapsulation efficiency (97.4%) of PCs. In contrast to free extract, extract-loaded phytosomes had higher antioxidant activity after 6 months storage. Oral administration of extract-loaded phytosomes and free extract did not lead to lipidic profile changes and were within referenced normal ranges, as well as glycaemia levels and urine parameters. The results highlighted the potential of persimmon PCs as food supplements or pharmacological tools, suggesting a promising and safe phytosomal formulation containing bioactive agents of persimmon that could lead to health benefits.

Thermal Stress in Melon Plants: Phytoprostanes and Phytofurans as Oxidative Stress Biomarkers and the Effect of Antioxidant Supplementation

The extreme temperatures generated in the melon crop, early harvest, induce an increase in reactive oxygen species (ROS) plant levels leading to oxidative stress. Phytoprostanes (PhytoPs) and phytofurans (PhytoFs) are plant metabolites derived from α-linolenic acid oxidation induced by ROS. The aims of this work were to evaluate PhytoPs and PhytoFs as oxidative stress biomarkers in leaves of melon plants thermally stressed. In addition, to fortify melon plant antioxidant defenses, foliar spraying was assayed using salicylic and gallic acid solutions and Ilex paraguariensis extract. PhytoP and PhytoF concentration ranges were 109-1146 and 130-4400 ng/g, respectively. Their levels in stressed plants were significantly higher than in nonstressed samples. In stressed samples treated with I. paraguariensis, PhytoP and PhytoF levels were significantly lower than in stressed samples without antioxidants. PhytoPs and PhytoFs represent relevant oxidative stress biomarkers in melon leaves. The use of natural antioxidants could reduce plant oxidative stress.

Gallic acid induces mitotic catastrophe and inhibits centrosomal clustering in HeLa cells

Cancer cells divide rapidly, providing medical targets for anticancer agents. The polyphenolic gallic acid (GA) is known to be toxic for certain cancer cells. However, the cellular mode of action has not been elucidated. Therefore, the current study addressed a potential effect of GA on the mitosis of cancer cells. GA inhibited viability of HeLa cells in a dose-dependent and time-dependent manner. We could show, using fluorescence-activated cell sorting (FACS), that this inhibition was accompanied by elevated frequency of cells arrested at the G2/M transition. This cell-cycle arrest was accompanied by mitotic catastrophe, and formation of cells with multiple nuclei. These aberrations were preceded by impaired centrosomal clustering. We arrive at a model of action, where GA inhibits the progression of the cell cycle at the G2/M phase by impairing centrosomal clustering which will stimulate mitotic catastrophe. Thus, GA has potential as compound against cervical cancer.

Aiweixin, a traditional Uyghur medicinal formula, protects against chromium toxicity in Caenorhabditis elegans

Background

Aiweixin (AWX) is a traditional Uyghur medicine prescription, and has been mainly used to treat heart and brain diseases for a long time. Previous studies indicated that AWX had therapeutic effects in a rat model of myocardial ischemia reperfusion injury. In this study, we investigate whether AWX has protective effects against chromium toxicity in Caenorhabditis elegans (C. elegans).

Methods

The AWX decoction was the conventional product for clinical use. It was added into M9 buffer in a certain volume for the treatment to the wild-type C. elegans and mutational worms, daf-16, glp-1(notch), daf-2, rsks-1 and eat-2. Assays for hexavalent chromium {Cr(VI)} stress and reactive oxygen species (ROS) production were used.

Results

We found that AWX at moderate contents (0.083, 0.1, 0.125 volume of AWX/total volume) increased resistance of C. elegans to Cr(VI) exposure, although higher contents of AWX are toxic for C. elegans. The protective effect of AWX was DAF-16-dependent, but independent on the DAF-2, GLP-1, RSKS-1 and EAT-2. AWX (0.1 volume of AWX/total volume) significantly reduced ROS production of C. elegans induced by Cr(VI) exposure.

Conclusion

These results indicated the AWX protected against the toxicity of Cr(VI) in C. elegans, and the oxidative stress protective mechanism in worms should be involved.