Impact of antiseptics on radical metabolism, antioxidant status and genotoxic stress in blood cells: povidone-iodine versus octenidine dihydrochloride

Counteraction of Oxidative Stress by Vitamin E Affects Epigenetic Regulation by Increasing Global Methylation and Gene Expression of MLH1 and DNMT1 Dose Dependently in Caco-2 Cells

Obesity- or diabetes-induced oxidative stress is discussed as a major risk factor for DNA damage. Vitamin E and many polyphenols exhibit antioxidative activities with consequences on epigenetic regulation of inflammation and DNA repair. The present study investigated the counteraction of oxidative stress by vitamin E in the colorectal cancer cell line Caco-2 under normal (1 g/l) and high (4.5 g/l) glucose cell culture condition. Malondialdehyde (MDA) as a surrogate marker of lipid peroxidation and reactive oxygen species (ROS) was analyzed. Gene expression and promoter methylation of the DNA repair gene MutL homolog 1 (MLH1) and the DNA methyltransferase 1 (DNMT1) as well as global methylation by LINE-1 were investigated. Results revealed a dose-dependent counteracting effect of vitamin E on H₂O₂-induced oxidative stress. Thereby, 10 μM vitamin E proved to be more efficient than did 50 μM in reducing MDA. Further, an induction of MLH1 and DNMT1 gene expression was noticed, accompanied by an increase in global methylation. Whether LINE-1 hypomethylation is a cause or effect of oxidative stress is still unclear. In conclusion, supplementation of exogenous antioxidants like vitamin E in vitro exhibits beneficial effects concerning oxidative stress as well as epigenetic regulation involved in DNA repair.

The protective roles of some lichen species on colloidal bismuth subcitrate genotoxicity

Medicinal plants are increasingly being projected as suitable alternative source for the treatment of various diseases. However, toxic effects resulting from therapeutic bismuth compounds are still documented in animals and humans. This study described the genetic effects of five common lichen species and compared their activities on the genotoxicity induced by the colloidal bismuth subcitrate. After the application of colloidal bismuth subcitrate and lichen extracts, separate and together, human whole blood cultures were assessed by sister-chromatid exchange (SCE) and micronucleus tests. According to our results, the frequencies of SCE and micronucleus rate in peripheral lymphocytes were significantly increased by colloidal bismuth subcitrate (at dose 5 μg/mL) compared with controls. However, lichen extracts had no genotoxic effect. The order of anti-genotoxicity efficacy against colloidal bismuth subcitrate was Pseudevernia furfuracea, Dermotocarpon intestiniforme, Ramalina capitata, Parmelia pulla, respectively. However, Rhizoplaca melanophthalma did not show any effect against colloidal bismuth subcitrate genotoxicity. Present findings showed that the protective roles of lichens studied were dose related. In conclusion, this is the first study report describing the therapeutic potential of lichens against drug genotoxicity in human blood.

Antiseptic use in the neonatal intensive care unit - a dilemma in clinical practice: An evidence based review

Infants in the neonatal intensive care unit are highly susceptible to healthcare associated infections (HAI), with a substantial impact on mortality, morbidity and healthcare costs. Effective skin disinfection with topical antiseptic agents is an important intervention in the prevention or reduction of HAI. A wide array of antiseptic preparations in varying concentrations and combinations has been used in neonatal units worldwide. In this article we have reviewed the current evidence of a preferred antiseptic of choice over other agents for topical skin disinfection in neonates. Chlorhexidine (CHG) appears to be a promising antiseptic agent; however there exists a significant concern regarding the safety of all agents used including CHG especially in preterm and very low birth weight infants. There is substantial evidence to support the use of CHG for umbilical cord cleansing and some evidence to support the use of topical emollients in reducing the mortality in infants born in developing countries. Well-designed large multicentre randomized clinical trials are urgently needed to guide us on the most appropriate and safe antiseptic to use in neonates undergoing intensive care, especially preterm infants.

Management of non-healable or maintenance wounds with topical povidone iodine

Although complete healing may appear to be the logical goal for most patients and clinicians, some wounds do not have the potential to heal due to a number of factors such as inadequate vasculature, coexisting medical conditions and medications that prohibit the healing process. Local management of wounds that are considered to have poor potential for healing remains elusive. The purpose of this article is to review the evidence that supports the use of topical antiseptic agents in non-healable wounds. Retrospective chart audit was conducted to evaluate the use of povidone iodine in the management of wounds that were deemed to have poor healing potential.

Well-trained, healthy triathletes experience no adverse health risks regarding oxidative stress and DNA damage by participating in an ultra-endurance event

Also physical exercise in general is accepted to be protective, acute and strenuous exercise has been shown to induce oxidative stress. Enhanced formation of free radicals leads to oxidation of macromolecules and to DNA damage. On the other hand ultra-endurance events which require strenuous exercise are very popular and the number of participants is continuously increasing worldwide. Since only few data exists on Ironman triathletes, who are prototypes of ultra-endurance athletes, this study was aimed at assessing the risk of oxidative stress and DNA damage after finishing a triathlon and to predict a possible health risk. Blood samples of 42 male athletes were taken 2 days before, within 20 min after the race, 1, 5 and 19 days post-race. Oxidative stress marker increased only moderately after the race and returned to baseline after 5 days. Marker of DNA damage measured by the SCGE assay with and without restriction enzymes as well as by the sister chromatid exchange assay did either show no change or deceased within the first day after the race. Due to intake during the race and the release by the cells plasma concentrations of vitamin C and α-tocopherol increased after the event and returned to baseline 1 day after. This study indicates that despite a temporary increase in some oxidative stress markers, there is no persistent oxidative stress and no DNA damage in response to an Ironman triathlon in trained athletes, mainly due to an appropriate antioxidant intake and general protective alterations in the antioxidant defence system.

Cytotoxic and apoptotic effects of single and mixed oxides of beta-sitosterol on HepG2-cells

While health implications caused by cholesterol oxidation products (COPs) seem to be generally accepted, research on phytosterol oxidation products (POPs) is still limited. Since POPs are commercially not available knowledge on their toxic activities is mainly derived from blends instead of pure compounds. Therefore the aim of the present study was to examine the cytotoxicity of three individual oxidation products of beta-sitosterol, 7-ketositosterol, 7beta-OH-sitosterol, 7alpha-OH-sitosterol, a mixture of 6beta-OH-3-keto-sitosterol/6alpha-OH-3-keto-sitosterol (ratio 4:3) and a mixture of polar oxides towards HepG2-cells. All tested compounds were found to reduce cell viability in a significant and concentration dependent way, particularly 7-keto- and 7alpha-OH-sitosterol showed to be highly active. Only for 7-ketositosterol an increase in early apoptotic cells was observed. Enhancement of O(2)(-) production was assessed for all oxides, whereas malondialdehyd (MDA) levels were increased by 7-keto- and 7alpha-OH-sitosterol only. However, cell death did not appear to be necessarily dependent on the generation of oxidative stress. Further no DNA strand breaks were observed with the COMET assay. By assessing the accumulation of single oxidation products in the cells a link between higher proportions of oxides inside the cells and their cytotoxic potential could be found.

Anti-genotoxic effect of hydrated sodium calcium aluminosilicate on genotoxicity to human lymphocytes induced by aflatoxin B1

The anti-genotoxic potential of hydrated sodium calcium aluminosilicate (HSCAS) was investigated using sister chromatid exchanges (SCEs) induced by aflatoxin B1 (AFB1) as genotoxic endpoint in human lymphocytes. Whole blood samples from two healthy male donors were used for this experiment and the effects of different concentrations of HSCAS (5 x 10(-6) and 1 x 10(-5) M) and AFB1 (1, 5 and 10 microM) were tested. The present results established that the frequencies of SCEs (at doses of 5 and 10 microM except for 1 microM) in lymphocytes were significantly increased by AFB1 compared to controls. When HSCAS was added alone at a molar ratio of 5 x 10(-6) and 1 x 10(-5), lymphocytes did not show significant increases in SCE frequencies, but SCE frequencies induced by the various concentrations of AFB1 could be significantly reduced by the presence of HSCAS (at both doses). In fact, HSCAS at 1 x 10(-5) M completely inhibited SCE formations caused by AFB1. These results suggest for the first time, that HSCAS can antagonize the ability of AFB1 to cause DNA damage that leads to the formation of SCEs.

Synthesis, antifungal and haemolytic activity of a series of bis(pyridinium)alkanes

A series of bis(pyridinium)alkanes have been prepared and their antifungal activity, haemolytic activity and ability to inhibit fungal phospholipase B1 have been investigated, together with those of the commercially available antiseptics octenidine and dequalinium. Removal of the amino substituents from the pyridinium rings resulted in a significant decrease in antifungal activity. However, shortening or removing the alkyl chains attached to the amino groups had little effect on antifungal activity and significantly reduced haemolytic activity. Only octenidine was a strong inhibitor of fungal phospholipase B1.

The in vitro effective antiviral action of povidone-iodine (PVP-I) may also have therapeutic potential by its intravenous administration diluted with Ringer's solution

The use of povidone-iodine (PVP-I) is well known in clinical medical practice. In vitro studies of cell cultures infected by HIV and H5N1 virus have shown that PVP-I has an antiviral action, while the cell hosts were not affected and survived. It is therefore worth investigating whether PVP-I, diluted with Ringer's solution, may have a therapeutic effect by parenteral administration. Specifically, the question is whether small concentrations of intravenous PVP-I could be well tolerated by the human organism, and in addition, if it would be possible to detect a beneficial activity. Its intravenous use may have a potential value against infections (by microbes, viruses, fungi and parasites), as well as an anti-inflammatory activity, especially in cases where antibiotics are ineffective. It could be used as a blood disinfectant, for treating burns, for the prevention of cancer, for the therapy of H5N1 influenza after its mutation, and other potential applications.