Waterpipe smoke: source of toxic and carcinogenic VOCs, phenols and heavy metals?

The use of the waterpipe, a traditional aid for the consumption of tobacco, has spread worldwide and is steadily increasing especially among the youth. On the other hand, there is a lack of knowledge regarding the composition of mainstream waterpipe smoke and the toxicological risks associated with this kind of smoking habit. Using a standardized machine smoking protocol, mainstream waterpipe smoke was generated and further analyzed for twelve volatile organic compounds (VOCs) and eight phenolic compounds by applying gas chromatography-mass spectrometry and reverse-phase high-performance liquid chromatography-fluorescence detection, respectively. Additionally, seventeen elements were analyzed in waterpipe tobacco and charcoal prior to and after smoking, applying inductively coupled plasma-mass spectrometry to assess the maximum exposure of these elements. For the first time ever, we have been able to show that waterpipe mainstream smoke contains high levels of the human carcinogen benzene. Compared with cigarette smoke yields, the levels were 6.2-fold higher, thus representing a significant health hazard for the waterpipe smoker. Furthermore, we found that waterpipe mainstream smoke contains considerable amounts of catechol, hydroquinone and phenol, each of which causing some health concern at least. The analysis of waterpipe tobacco and charcoal revealed that both matrices contained considerable amounts of the toxic elements nickel, cadmium, lead and chromium. Altogether, the data on VOCs, phenols and elements presented in this study clearly point to the health hazards associated with the consumption of tobacco using waterpipes.

Metal release from coffee machines and electric kettles.

The release of elemental ions from 8 coffee machines and 11 electric kettles into food simulants was investigated. Three different types of coffee machines were tested: portafilter espresso machines, pod machines and capsule machines. All machines were tested subsequently on 3 days before and on 3 days after decalcification. Decalcification of the machines was performed with agents according to procedures as specified in the respective manufacturer's manuals. The electric kettles showed only a low release of the elements analysed. For the coffee machines decreasing concentrations of elements were found from the first to the last sample taken in the course of 1 day. Metal release on consecutive days showed a decreasing trend as well. After decalcification a large increase in the amounts of elements released was encountered. In addition, the different machine types investigated clearly differed in their extent of element release. By far the highest leaching, both quantitatively and qualitatively, was found for the portafilter machines. With these products releases of Pb, Ni, Mn, Cr and Zn were in the range and beyond the release limits as proposed by the Council of Europe. Therefore, a careful rinsing routine, especially after decalcification, is recommended for these machines. The comparably lower extent of release of one particular portafilter machine demonstrates that metal release at levels above the threshold that triggers health concerns are technically avoidable.

Leishmania promastigotes lack phosphatidylserine but bind annexin V upon permeabilization or miltefosine treatment.

The protozoan parasite Leishmania is an intracellular pathogen infecting and replicating inside vertebrate host macrophages. A recent model suggests that promastigote and amastigote forms of the parasite mimic mammalian apoptotic cells by exposing phosphatidylserine (PS) at the cell surface to trigger their phagocytic uptake into host macrophages. PS presentation at the cell surface is typically analyzed using fluorescence-labeled annexin V. Here we show that Leishmania promastigotes can be stained by fluorescence-labeled annexin V upon permeabilization or miltefosine treatment. However, combined lipid analysis by thin-layer chromatography, mass spectrometry and (31)P nuclear magnetic resonance (NMR) spectroscopy revealed that Leishmania promastigotes lack any detectable amount of PS. Instead, we identified several other phospholipid classes such phosphatidic acid, phosphatidylethanolamine; phosphatidylglycerol and phosphatidylinositol as candidate lipids enabling annexin V staining.

Bacterial predators possess unique membrane lipid structures.

Bdellovibrio-and-like organisms (BALO) are a phylogenetically diverse group of predatory prokaryotes that consists of the two families Bdellovibrionaceae and Bacteriovoracaceae. We investigated the phospholipid composition of the three important BALO strains Bacteriovorax stolpii (DSM 12778), Bdellovibrio bacteriovorus HD100 (DSM 50701) and Peredibacter starrii (DSM 17039). We confirmed the presence of sphingophosphonolipids in B. stolpii, while we characterized sphingophosphonolipids with a 2-amino-3-phosphonopropanate head group for the first time. In B. bacteriovorus HD100 phosphatidylthreonines were found and, thus, B. bacteriovorus is the second prokaryote investigated so far possessing this rare lipid class. In the third analyzed organism, P. starrii, we observed phosphatidylethanolamine structures with an additional N-glutamyl residue, which form the first reported class of amino acid-containing phosphatidylethanolamines.

Chemical structure of Bacteriovorax stolpii lipid A.

Bdellovibrionales is a phylogenetically diverse group of predatory prokaryotes, which consists of the two families Bdellovibrionaceae and Bacteriovoracaceae. We describe LPS and lipid A of the type strain Bacteriovorax stolpii DSM 12778, representing the first characterized endotoxin of a Bacteriovoracaceae member. It has a smooth form LPS, which was identified by SDS-polyacrylamide gel electrophoresis. The lipid A structure was determined by combined gas chromatography-mass spectrometry, electrospray ionization mass spectrometry and NMR spectroscopy. Its backbone consists of two beta-(1-->6)-linked 2,3-diamino-2,3-dideoxy-D-glucopyranoses (GlcpN3N) carrying a pyrophosphoethanolamine at O-4' of the non-reducing sugar and a phosphate group linked to O-1 of the reducing GlcpN3N. Positions 2, 3, 2' and 3' of the two GlcpN3N are acylated with primary 3-hydroxy fatty acids and one of those carries a secondary fatty acid.