There is a risk of crimes remaining unsolved when no matching DNA profiles or fingermarks are found. If this is the case, forensic investigations are faced with a significant shortage of evidence and ...information regarding the unknown perpetrator and/or victim as well as any missing persons. However, a rather commonly found biological trace encountered at crime scenes is human hair. As hair acts as a biochemical reservoir, it may contain valuable information regarding one’s characteristics and habits. This study aimed to build an analytical method capable of determining a marker set of relevant metabolites in hair, eventually building up a profile of its donor. To find potential markers, an untargeted metabolomics approach was developed to select and identify statistically significant features. For that purpose, a total of 68 hair samples were collected at several hairdresser shops in varying neighbourhoods. Compound extraction was achieved via methanolic incubation overnight and analysis performed using a high-resolution mass spectrometry (HRMS) Orbitrap Q Exactive Focus. The acquired data was uploaded and statistically evaluated using two free online software/libraries, where a total of eight compounds have given a match on both tools. Their presumptive identity was confirmed using reference standards and consequently added to a dynamic target donor profiling list. These results show the potential of using untargeted metabolomics for the search for lifestyle biomarkers capable of differentiating individuals. Such tools are of paramount importance in a forensic setting with little or no evidence available and no clear tactical leads.
•An untargeted metabolomics method was developed to aid evidence-scarce cases.•Hair proves to be an efficient forensic reservoir for one’s lifestyle.•A pioneering untargeted approach was used to unravel biomarkers in hair.
We assessed the prevalence of potential health hazards to intervention staff and cannabis growers in Belgian indoor cannabis plantations. Surface mold swab samples were taken at 16 Belgian indoor ...plantations contained mostly Penicillium sp. and Aspergillus sp. However, their precise health impact on intervention staff and illicit growers is unclear as no molds spore concentrations were measured. Atmospheric gas monitoring in the studied cannabis plantations did not reveal dangerous toxic substances. Health symptoms were reported by 60% of 221 surveyed police, but could not be linked to specific plantation characteristics. We conclude that Belgian indoor cannabis plantations pose a potential health threat to growers and intervention staff. AS there are currently no clear safety guidelines for seizure and dismantling of Belgian indoor cannabis plantations, we recommend first responders to follow strict safety rules when entering the growth rooms, which include wearing appropriate personal protective equipment.
Phlotoxin-1 (PhlTx1) is a peptide previously identified in tarantula venom (
species) that belongs to the inhibitory cysteine-knot (ICK) toxin family. Like many ICK-based spider toxins, the synthesis ...of PhlTx1 appears particularly challenging, mostly for obtaining appropriate folding and concomitant suitable disulfide bridge formation. Herein, we describe a procedure for the chemical synthesis and the directed sequential disulfide bridge formation of PhlTx1 that allows for a straightforward production of this challenging peptide. We also performed extensive functional testing of PhlTx1 on 31 ion channel types and identified the voltage-gated sodium (Na
) channel Na
1.7 as the main target of this toxin. Moreover, we compared PhlTx1 activity to 10 other spider toxin activities on an automated patch-clamp system with Chinese Hamster Ovary (CHO) cells expressing human Na
1.7. Performing these analyses in reproducible conditions allowed for classification according to the potency of the best natural Na
1.7 peptide blockers. Finally, subsequent in vivo testing revealed that intrathecal injection of PhlTx1 reduces the response of mice to formalin in both the acute pain and inflammation phase without signs of neurotoxicity. PhlTx1 is thus an interesting toxin to investigate Na
1.7 involvement in cellular excitability and pain.
Highlights • MSI is useful tool in studying the effect of cosmetic treatment on cocaine in hair. • Bleaching hair peroxide decreases the detectability of cocaine in user hair. • Melanin–cocaine bonds ...are broken and cocaine is degraded into reaction products. • Unbound cocaine and reaction products are washed out removing evidence of cocaine use.
Kbot55 is a 39 amino acid peptide isolated from the venom of the Tunisian scorpion Buthus occitanus tunetanus. This peptide is cross-linked by 3 disulfide bridges and has a molecular mass of ...4128.65Da. Kbot55 is very low represented in the venom and thus represents a challenge for biochemical characterization. In this study, Kbot55 has been subjected to a screening on ion channels expressed in Xenopus laevis oocytes. It was found that Kbot55 targets voltage-gated potassium channels with high affinity. Kbot55 shows very low amino acid identity with other scorpion potassium toxins and therefore was considered a bona fide novel type of scorpion toxin. Sequence alignment analysis indicated that Kbot55 is the first representative of the new α-Ktx31 subfamily and therefore was classified as α-Ktx31.1.
Gigantoxin I, isolated from sea anemone Stichodactyla gigantea, was previously described as the first epidermal growth factor (EGF)-like toxin from natural origin. In this study, we discovered the ...interaction between the transient receptor potential vanilloid subtype I (TRPV1) channels and gigantoxin I. The TRPV1 channel is a non-selective cation channel involved in pain sensation and is described as pharmacological target of cnidaria venom. Our results highlight the involvement of the epidermal growth factor receptor/phospholipaseA2/arachidonic acid/lipoxygenase (EGFR/PLA2/AA/ LOX) pathway in the indirect activation of TRPV1 channels by gigantoxin I. This is the first time that this pathway is described in the indirect activation of TRPV1 channels by toxins. This knowledge not only gives insights into the possible induced effects by this new group of toxins, but also leads to a better understanding of the regulatory mechanism of TRPV1 channels themselves.
In this study, we isolated and pharmacologically characterized the first α-like toxin from the venom of the scarcely studied Iranian scorpion
Odonthobuthus doriae. The toxin was termed OD1 and its ...primary sequence was determined: GVRDAYIADDKNCVYTCASNGYCNTECTKNGAESGYCQWIGRYGNACWCIKLPDEVPIRIPGKCR. Using the two-electrode voltage clamp technique, the pharmacological effects of OD1 were studied on three cloned voltage-gated Na
+ channels expressed in
Xenopus laevis oocytes (Na
v1.2/β
1, Na
v1.5/β
1, para/tipE). The inactivation process of the insect channel, para/tipE, was severely hampered by 200
nM of OD1 (EC
50
=
80
±
14
nM) while Na
v1.2/β
1 still was not affected at concentrations up to 5
μM. Na
v1.5/β
1 was influenced at micromolar concentrations.
Certain amphibians provide themselves with a chemical defense by accumulating lipophilic alkaloids into skin glands from dietary arthropods. Examples of such alkaloids are pumiliotoxins (PTXs). In ...general, PTXs are known as positive modulators of voltage-gated sodium channels (VGSCs). Unlike other PTXs, PTX
251D does not share this characteristic. However, mice and insect studies showed that PTX
251D is highly toxic and to date the basis of its toxicity remains unknown.
In this work, we searched for the possible target of PTX
251D. The toxin was therefore made synthetically and tested on four VGSCs (mammalian rNa
v1.2/β
1, rNa
v1.4/β
1, hNa
v1.5/β
1 and insect
Para/tipE) and five voltage-gated potassium channels (VGPCs) (mammalian rK
v1.1-1.2, hK
v1.3, hK
v11.1 (hERG) and insect
Shaker IR) expressed heterologously in
Xenopus laevis oocytes, using the two-electrode voltage clamp technique.
PTX
251D not only inhibited the Na
+ influx through the mammalian VGSCs but also affected the steady-state activation and inactivation. Interestingly, in the insect ortholog, the inactivation process was dramatically affected. Additionally, PTX
251D inhibited the K
+ efflux through all five tested VGPCs and slowed down the deactivation kinetics of the mammalian VGPCs. hK
v1.3 was the most sensitive channel, with an IC
50 value 10.8±0.5
μM. To the best of our knowledge this is the first report of a PTX affecting VGPCs.
Over the last couple of years, transient receptor potential vanilloid 1(TRPV1) channels have been a hot topic in ion channel research. Since this research field is still rather new, there is not much ...known about the working mechanism of TRPV1 and its ligands. Nevertheless, the important physiological role and therapeutic potential are promising. Therefore, extensive research is going on and a lot of natural as well as synthetic compounds are already described. In this review, we briefly give an overview of capsaicin's history and the current knowledge of its working mechanism and physiological role. We discuss the best known plant molecules acting on TRPV1 and highlight the latest discovery in TRPV1 research: animal venoms and toxins acting on TRPV1 channels. In an effort to give the complete image of TRPV1 ligands known today, the most promising synthetic compounds are presented. Finally, we present a novel pharmacophore model describing putative ligand binding domains.
PDF
