A Whiff of Sulfur: One Wind a Day Keeps the Doctor Away.

Reactive Sulfur Species (RSS), such as allicin from garlic or sulforaphane from broccoli, are fre-quently associated with biological activities and possible health benefits in animals and humans. Among these Organic Sulfur Compounds (OSCs) found in many plants and fungi, the Volatile Sulfur Compounds (VSCs) feature prominently, not only because of their often-pungent smell, but also because they are able to access places which solids and solutions cannot reach that easily. Indeed, inorganic RSS such as hydrogen sulfide (H2S) and sulfur dioxide (SO2) can be used to lit-erally fumigate entire rooms and areas. Similarly, metabolites of garlic, such as allyl methyl sulfide (AMS), are formed metabolically in humans in lower concentrations and reach the airways from inside the body as part of one's breath. Curiously, H2S is also formed in the gastrointestinal tract by gut bacteria, and the question of if and for which purpose this gas then crosses the barriers and enters the body is indeed a delicate matter for equally delicate studies. In any case, nature is surprisingly rich in such VSCs, as fruits (for instance, the infamous durian) demonstrate, and therefore these VSCs represent a promising group of compounds for further studies.

Potential health effects of brewers' spent grain as a functional food ingredient assessed by markers of oxidative stress and inflammation following gastro-intestinal digestion and in a cell model of the small intestine.

Brewer's spent grains (BSG) are a by-product of the beer-brewing industry, often employed as animal feeding stuffs. With BSG being rich not only in proteins, lipids, and dietary fiber but also in certain phytochemicals, it constitutes a potentially valuable food source that could be employed as a functional food, e.g. against chronic inflammatory diseases. Several types of bread were prepared with various amounts of BSG as flour replacement (0, 10, 20, 40, 60, 80 and 100%), either employing wet BSG or dried BSG after pressing. Total phenolics, flavonoids, insoluble dietary fiber, as well as antioxidant capacity (FRAP, ABTS) were measured in the bread, before and after simulated gastro-intestinal digestion. Furthermore, we investigated digested BSG and bread-containing BSG for their capability to alter oxidative stress (Nrf2, malondialdehyde) and inflammation (IL-6, IL-8, NO, and PGE2) in a Caco-2 cell culture model of the small intestine. Incorporation of BSG significantly and dose-dependently enhanced the amount of dietary fiber in the product, as well as total phenolics, flavonoids, and antioxidant capacity, by over 10-fold, 3-fold, 4-fold and 5-fold, respectively, when replacing all of the flour with BSG. This pattern remained after in vitro digestion. However, digesta failed to show significant antioxidant or anti-inflammatory effects on the biomarkers observed in the cell model. Consuming 150 g of such a BSG-bread (wet based) would supply the proposed RDA of 25 g d-1 dietary fiber and could be a healthy product valorizing BSG.

Selenomethionine: A Pink Trojan Redox Horse with Implications in Aging and Various Age-Related Diseases.

Selenium is an essential trace element. Although this chalcogen forms a wide variety of compounds, there are surprisingly few small-molecule organic selenium compounds (OSeCs) in biology. Besides its more prominent relative selenocysteine (SeCys), the amino acid selenomethionine (SeMet) is one example. SeMet is synthesized in plants and some fungi and, via nutrition, finds its way into mammalian cells. In contrast to its sulfur analog methionine (Met), SeMet is extraordinarily redox active under physiological conditions and via its catalytic selenide (RSeR')/selenoxide (RSe(O)R') couple provides protection against reactive oxygen species (ROS) and other possibly harmful oxidants. In contrast to SeCys, which is incorporated via an eloquent ribosomal mechanism, SeMet can enter such biomolecules by simply replacing proteinogenic Met. Interestingly, eukaryotes, such as yeast and mammals, also metabolize SeMet to a small family of reactive selenium species (RSeS). Together, SeMet, proteins containing SeMet and metabolites of SeMet form a powerful triad of redox-active metabolites with a plethora of biological implications. In any case, SeMet and its family of natural RSeS provide plenty of opportunities for studies in the fields of nutrition, aging, health and redox biology.

Unleashing the Biological Potential of Fomes fomentarius via Dry and Wet Milling.

Fomes fomentarius, usually referred to as tinder conk, is a common wood-based fungus rich in many interesting phytochemicals and with an unique porous structure. Dry or wet ball milling of this sponge on a planetary mill results in small particles with sizes in the range of 10 µm or below. Suspended in water and without preservatives or other stabilizers, the resulting micro-suspensions are sterile for around six days, probably due to the increased temperatures of around 80 °C especially during the wet milling process. The suspensions also exhibit excellent antioxidant activities as determined in the DPPH, ferric reducing antioxidant potential (FRAP) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) assays. In the DPPH assay, IC50 values of 0.02-0.04% w/v and 0.04% w/v were observed for dry and wet milled samples, respectively. In the FRAP assay, IC50 values of <0.02% w/v and 0.04% w/v were observed for dry and wet milled samples, respectively. In contrast, the ABTS assay provided IC50 values of 0.04% w/v and 0.005% w/v, respectively. Notably, this activity is mostly-albeit not exclusively-associated with the highly porous particles and their large surfaces, although some active ingredients also diffuse into the surrounding aqueous medium. Such suspensions of natural particles carrying otherwise insoluble antioxidants on their surfaces provide an interesting avenue to unleash the antioxidant potential of materials such as sponges and barks. As dry milling also enables longer storage and transport, applications in the fields of medicine, nutrition, agriculture, materials and cosmetics are feasible.

Small Molecule Catalysts with Therapeutic Potential.

Catalysts are employed in many areas of research and development where they combine high efficiency with often astonishing selectivity for their respective substrates. In biology, biocatalysts are omnipresent. Enzymes facilitate highly controlled, sophisticated cellular processes, such as metabolic conversions, sensing and signalling, and are prominent targets in drug development. In contrast, the therapeutic use of catalysts per se is still rather limited. Recent research has shown that small molecule catalytic agents able to modulate the redox state of the target cell bear considerable promise, particularly in the context of inflammatory and infectious diseases, stroke, ageing and even cancer. Rather than being "active" on their own in a more traditional sense, such agents develop their activity by initiating, promoting, enhancing or redirecting reactions between biomolecules already present in the cell, and their activity therefore depends critically on the predisposition of the target cell itself. Redox catalysts, for instance, preferably target cells with a distinct sensitivity towards changes in an already disturbed redox balance and/or increased levels of reactive oxygen species. Indeed, certain transition metal, chalcogen and quinone agents may activate an antioxidant response in normal cells whilst at the same time triggering apoptosis in cancer cells with a different pre-existing "biochemical redox signature" and closer to the internal redox threshold. In pharmacy, catalysts therefore stand out as promising lead structures, as sensor/effector agents which are highly effective, fairly selective, active in catalytic, i.e., often nanomolar concentrations and also very flexible in their structural design.