Ultrasensitive determination of DNA oxidation products by gas chromatography–tandem mass spectrometry and the role of antioxidants in the prevention of oxidative damage

Development and optimization of Clitoria teratea synthesized silver nanoparticles and its application to nanogel systems for wound healing

OBJECTIVE

The present research deals with sequential optimization strategy based on Central Composite Design to optimize the process variables for efficient production of Clitoria teratea (CLT) synthesized silver nanoparticles (AgNPs) using biological synthesis.

METHODS

Two substantial factors influencing the dependent variables viz UV-visible absorbance, particle size, zeta potential and polydispersity index (PDI) were identified as NaOH concentration, RH concentration, temperature as independent variables. In-vitro and ex-vivo studies of prepared CLT-AgNPs gel and marketed gel were carried out using dialysis membrane and egg membrane, respectively. In addition, antimicrobial study was also performed on the bacterial strains.

RESULTS

The particles size (114 nm), PDI (0.45), and zeta potential (-29.5 mV) of optimized formulation were found, respectively. In-vitro profile of AgNPs from prepared CLT-AgNPs gel was noted (95.6%) in 8 h. It was found that the prepared CLT-AgNPs gel stimulates fibroblast and agranulocytosis development resulting better and timely wound healing.

CONCLUSIONS

The prepared CLT-AgNPs gel can be as a potential substitute in the management and treatment of acute and chronic wounds.

Biomarkers of Oxidative Stress and Antioxidant Defense

A number of reactive oxygen and nitrogen species are produced during normal metabolism in human body. These species can be both radical and non-radical and have varying degrees of reactivity. Although they have some important functions in the human body, such as contributing to signal transmission and the immune system, their presence must be balanced by the antioxidant defense system. The human body has an excellent intrinsic enzymatic antioxidant system in addition to different non-enzymatic antioxidants having small molecular masses. An extrinsic source of antioxidants are foodstuffs such as fruits, vegetables, herbs and spices, mostly rich in polyphenols. When the delicate biochemical balance between oxidants and antioxidants is disturbed in favor of oxidants, "oxidative stress" conditions emerge, under which reactive species can cause oxidative damage to biomacromolecules such as proteins, carbohydrates, lipids and DNA. This oxidative damage is often associated with cancer, aging, and neurodegenerative disorders. Because reactive species are extremely short-lived, it is almost impossible to measure their concentrations directly. Although there are certain methods such as ESR / EPR that serve this purpose, they have some disadvantages and are quite costly systems. Therefore, products generated from oxidative damage of proteins, lipids and DNA are often used to quantify the extent of oxidative damage rather than direct measurement of reactive species. These oxidative damage products are usually known as biomarkers. Determination of the concentrations of these biomarkers and changes in the concentration of protective antioxidants can provide useful information for avoiding certain diseases and keep healthy conditions.

Phytochemical Profile and Biological Activities of Tendrils and Leaves Extracts from a Variety of Vitis vinifera L

Winery industry by-products have a great reuse potential in the pharmaceutical and cosmetic fields due to their bioactive compounds. This study investigates the phytochemical profile and the bioactivity of Vitis vinifera variety Fetească neagră tendrils extract (TE) and leaves extract (LE), intended to be used in oral hygiene products recommended in periodontal disease. The evaluation of the phenolic content was performed by colorimetric analysis. Liquid chromatography coupled with mass spectrometry was used to determine the chemical profile of the two extracts obtained from V. vinifera. Moreover, the antioxidant activity of the extracts was determined by spectrophotometric methods, as well as on human gingival fibroblasts (HGF) cell line. The cytocompatibility and cytoprotective effect against nicotine-induced cytotoxicity were tested, as well as the anti-inflammatory and antimicrobial effects. The TE showed higher total polyphenolic content, rich in rutin, compared to the leaves extract that displayed important amounts of isoquercitrin. The antioxidant effect was confirmed by both non-cellular and cellular tests. The cytocompatibility of the extracts was confirmed at a wide range of concentrations. The cytoprotective effect was demonstrated in HGF exposed to cytotoxic doses of nicotine; 300 µg/mL of both tested extracts decreased nicotine toxicity by approximately 20%. When challenged with E. coli polysaccharides, in HGF cells co-exposed to TE and LE, a reduction in the release of proinflammatory cytokines (IL-8, IL-6 and IL-1β) was observed. The extracts were both able to reduce the levels of reactive oxygen species and inflammatory cytokines, and had notable antimicrobial effects on pathogenic bacteria associated with periodontitis.

The antioxidant properties of the chestnut bee pollen extract and its preventive action against oxidatively induced damage in DNA bases

Chestnut bee pollen has potential nutritional and medicinal effects and is an important natural bee product. This study focused on the investigation of the antioxidant capacity and DNA damage inhibition ability of chestnut bee pollen (CBP) from Bursa (Turkey). The phenolic compounds (rosmarinic acid, vitexin, hyperoside, pinocembrin, trans-chalcone, apigenin, protocatechuic, and galangin) and carotenoids in CBPE were determined by HPLC-DAD (high-performance liquid chromatography-diode array detection). Additionally, the protective ability of CBPE against DNA damage by oxidation was investigated. In this study, it was determined that CBPE has a high total phenolic compound content, and the antioxidant capacity of CBPE inhibits DNA oxidation (34% reduction of DNA damage in Fenton reaction media). This study could reveal new information regarding the use of CBPE as a protective agent for DNA in the future. PRACTICAL APPLICATIONS: Phenolic compounds and carotenoids prevent some diseases because of their important biological activities. One of the potential food sources chestnut bee pollen contains sugar, carbohydrates, amino acids, proteins, lipids, vitamins, hormones, enzymes, and flavonoids. Chestnut bee pollen, which has protective activity against DNA oxidation, could be an excellent potential source of a protective agent against some degenerative diseases through future applications.

Quantification of DNA damage products by gas chromatography tandem mass spectrometry in lung cell lines and prevention effect of thyme antioxidants on oxidative induced DNA damage

Lung cancer has a high treatment cost and poor prognosis in comparison to other types of cancers. This work was involved in studying oxidative DNA base damage inhibition. Accordingly, standard carvacrol, thymol, thymoquinone with water and water-methanol extract of thyme (Origanum vulgare L. subsp. hirtum (link.) Ietswaart), thyme oil and thyme water were prepared and investigated for their efficacy to inhibit DNA oxidative damage formed by H₂O₂ in malignant lung cells (A549). The antioxidant capacity by ABTS assay was 271.73 ± 11.45 mg trolox equivalent/mL for thyme oil. HPLC analysis was carried out to determine the contents of different thyme extracts, results showing the presence of carvacrol, thymol, protocatechuic acid, caffeic acid, epicatechin and rosmarinic acid in water and water-methanol extracts while only carvacrol and thymol were found in thyme oil and thyme water. After DNA isolation from the cultured cells, the formed oxidative induced DNA damage products were analysed using GC-MS/MS. It was proven that the antioxidants in the cell culture media have succeeded to inhibit oxidative DNA base damage. Thymoquinone was shown to be the best protectant antioxidant among other antioxidants against the formation of oxidative DNA damage, whereas water-methanol extract of thyme was the best among the plant-sourced samples. Thymoquinone and thyme water-methanol extract were investigated for their efficacy on cultured healthy lung cells (BEAS-2B), and it was proven that they are efficient in protection against the oxidation of DNA of healthy lung cells too.

Investigation of antioxidant ability of grape seeds extract to prevent oxidatively induced DNA damage by gas chromatography-tandem mass spectrometry

Phenolic compounds have been studied elaborately for their efficacy to improve health and to protect against a wide variety of diseases. Herein this study, different analysis methods were implemented to evaluate the antioxidant properties of catechin and cyanidin using their standard substances and as they found in the grape seeds extracts. Total phenol contents were 107.39±8.94mg GAE/g dw of grape seeds for grape seed extract (GSE) and 218.32±10.66mg GAE/g dw of grape seeds for acid-hydrolyzed grape seed extract (AcGSE). The extracts were analyzed by HPLC-DAD system and the results showed the presence of catechin, gallic acid, chlorogenic acid and ellagic acid in the processed methanolic extract and cyanidin, gallic acid and ellagic acid in the processed acidified methanolic extract. The protective abilities of catechin and cyanidin were tested against the oxidation of DNA. The results showed that cyanidin has better protection of DNA against oxidation than catechin. GSE and AcGSE were revealed to inhibit the oxidatively induced DNA damage. GSE decreased about 57% of damage caused by the Fenton control sample. This study could show new aspects of the antioxidant profiles of cyanidin and catechin.