Forensic analysis of biological fluid stains on substrates by spectroscopic approaches and chemometrics: A review

BACKGROUND

Bodily fluid stains are one of the most relevant evidence that can be found at the crime scene as it provides a wealth of information to the investigators. They help to report on the individuals involved in the crime, to check alibis, or to determine the type of crime that has been committed. They appear as stains in different types of substrates, some of them porous, which can interfere in the analysis. The spectroscopy techniques combined with chemometrics are showing increasing potential for their use in the analysis of such samples due to them being fast, sensitive, and non-destructive.

FINDINGS

This is a comprehensive review of the studies that used different spectroscopic techniques followed by chemometrics for analysing biological fluid stains on several surfaces, and under various conditions. It focuses on the bodily fluid stains and the most suitable spectroscopic techniques to study forensic scientific problems such as the substrate's characteristics, the influence of ambient conditions, the aging process of the bodily fluids, the presence of animal bodily fluids and non-biological fluids (interfering substances), and the bodily fluid mixtures. The most widely used techniques were Raman spectroscopy and attenuated total reflection Fourier transform infrared spectroscopy (ATR FTIR). Nonetheless, other non-destructive techniques have been also used, like near infrared hyperspectral imaging (HSI-NIR) or surface enhanced Raman spectroscopy (SERS), among others. This work provides the criteria for the selection of the most promising non-destructive techniques for the effective in situ detection of biological fluid stains at crime scene investigations.

SIGNIFICANCE AND NOVELTY

The use of the proper spectroscopic and chemometric approaches on the crime scene is expected to improve the support of forensic sciences to criminal investigations. Evidence may be analysed in a non-destructive manner and kept intact for further analysis. They will also speed up forensic investigations by allowing the selection of relevant samples from occupational ones.

Activity and post antifungal effect of chlorpromazine and trifluopherazine against Aspergillus, Scedosporium and zygomycetes

The phenothiazine compounds chlorpromazine and trifluopherazine are antipsychotic agents that exhibit antimicrobial activity against bacteria, some protozoa and yeasts. Data of activity against filamentous fungi are lacking. The in vitro activity and postantifungal effect (PAFE) of chlorpromazine and trifluopherazine was determined against Aspergillus species, zygomycetes and Scedosporium species. In vitro susceptibility testing was performed with CLSI M38A and the PAFE was determined with previously established methods. Both drugs inhibited the growth of all fungi tested at concentrations of 16 to 64 microg ml(-1). For Aspergillus species the mean PAFE was 3.7 and 4.7 h; for zygomycetes, 3.1 and 3.4 h; for Scedosporium, 4.3 and 5.3 h for chlorpromazine and trifluoroperazine respectively. These are the first drugs shown to induce PAFE against Scedosporium. We show that phenothiazine compounds have in vitro antifungal activity and exhibit PAFE against a broad range of filamentous fungal pathogens. Although the exact mechanism of action is unknown, further studies are needed to explore the clinical usefulness of phenothiazine compounds.

The influence of long-term treatment with psychotropic drugs on cytochrome P450: the involvement of different mechanisms

This paper emphasises that besides the direct action of psychotropic drugs on cytochrome P450 (CYP) (i.e., the binding of the parent drug to the enzyme) indirect mechanisms of CYP-psychotropic interactions, namely the formation of CYP-reactive metabolite complexes and their influence on enzyme regulation, are also very important. The described interactions that are time-, drug- and CYP isoform-dependent may overlap during long-term treatment. The final result of the overlapping depends on the dosage and time interval after the last administration of a drug, which determines the concentration of the parent drug and its metabolites in the environment of the enzyme. These interactions may occur not only in the liver, but also in the brain, and may change the activity of CYP towards the metabolism of drugs, sex steroids, neurosteroids and amine neurotransmitters. The role of the CNS in the regulation of CYP by psychotropics and the significance of CYP-psychotropic interactions for pharmacological and clinical profiling of these drugs is discussed. In addition, different experimental approaches for studying CNS-acting drugs are compared.

Inhibition of rat liver CYP2D in vitro and after 1-day and long-term exposure to neuroleptics in vivo-possible involvement of different mechanisms

The aim of the present study was to investigate the influence of classic and atypical neuroleptics on the activity of rat CYP2D measured as a rate of ethylmorphine O-deethylation. The reaction was studied in control liver microsomes in the presence of neuroleptics, as well as in microsomes of rats treated intraperitoneally (i.p.) for 1-day or 2-weeks (twice a day) with pharmacological doses of the drugs (promazine, levomepromazine, thioridazine, perazine 10 mg kg(-1); chlorpromazine 3 mg kg(-1); haloperidol 0.3 mg kg(-1); risperidone 0.1 mg kg(-1); sertindole 0.05 mg kg(-1)), in the absence of the neuroleptics in vitro. Neuroleptics added in vitro to control liver microsomes decreased the activity of the rat CYP2D by competitive or mixed inhibition of the enzyme. Thioridazine (Ki=15 microM) was the most potent inhibitor of the rat CYP2D among the drugs studied, whose effect was more pronounced than that of the other neuroleptics tested: phenothiazines (Ki=18-23 microM), haloperidol (Ki=32 microM), sertindole (Ki=51 microM) or risperidone (Ki=165 microM). The investigated neuroleptics-when given to rats in vivo-also seemed to exert an inhibitory effect on CYP2D via other mechanisms. One-day exposure of rats to the classic neuroleptics decreased the activity of CYP2D in rat liver microsomes. After chronic treatment with the investigated neuroleptics, the decreased CYP2D activity produced by the phenothiazines was still maintained, while that caused by haloperidol diminished. Moreover, risperidone decreased the activity of that enzyme. The obtained results indicate drug- and time-dependent interactions between the investigated neuroleptics and the CYP2D subfamily of rat cytochrome P-450, which may proceed via different mechanisms: (1) competitive or mixed inhibition of CYP2D shown in vitro, the inhibitory effects of phenothiazines being stronger than those of haloperidol or atypical neuroleptics, but weaker than the effects of the respective drugs on human CYP2D6; (2) in vivo inhibition of CYP2D, produced by both 1-day and chronic treatment with phenothiazines, which suggests inactivation of enzyme by intermediate metabolites; (3) in vivo inhibition of CYP2D by risperidone, produced only by chronic treatment with the drug, which suggests its influence on the enzyme regulation.

Mouse liver microsomes (MLM) protect erythrocytes against trifluoperazine (TFP) induced and mechanical hemolysis which are due to TFP microsomal transformation and to the action of an unidentified water-soluble microsomal factor (UF)

Trifluoperazine (TFP), a phenothiazine derivative, produces either hemolysis or protection of erythrocytes under isosmotic conditions in a dose-dependent manner. The hemolytic effect of TFP is abolished in the presence of mouse liver microsomes (MLM) which is due, in part, to drug incorporation, transformation and a MLM enzyme driven metabolism. An unidentified water-soluble factor (or factors) derived from MLM has been found to protect erythrocytes against both mechanical and TFP-induced isosmotic hemolysis.

A kinetic study of the generation and decomposition of some phenothiazine free radicals formed during enzymatic oxidation of phenothiazines by peroxidase-hydrogen peroxide

A kinetic study of the oxidation of four different phenothiazines (Pts) by peroxidase-hydrogen peroxide was carried out. The free radical formed during the enzymatic oxidation suffers a non-enzymatic breakdown and the overall system was analysed and characterized. The non-enzymatic breakdown of the cation radical does not occur through a disproportionation mechanism but through a more complex mechanism. The kinetic parameters of the overall system were determined for the different Pts. These experimental data may serve in the understanding of the pharmacological action of Pts.

Mechanistic aspects of the oxidation of phenothiazine derivatives by methemoglobin in the presence of hydrogen peroxide

Mechanistic aspects of the reaction of hydrogen peroxide with methemoglobin with respect to phenothiazine oxidation have been studied. Three phenothiazines, methoxy- (MoPZ), chlor- (CPZ) and methoxycarbonylpromazine (MaPZ), have been used. These phenothiazines differ only in substitution at the 2-position, which contributes substantially to the electron-donating properties of these compounds. Reaction with hydrogen peroxide oxidizes methemoglobin to ferrylhemoglobin, which contains iron(IV)-oxo porphyrin moiety and a protein radical. The phenothiazines are oxidized by ferrylhemoglobin in the presence of H2O2 mainly to their sulfoxides, with a radical cation as intermediate. The conversion rates (MoPZ greater than CPZ greater than MaPZ) decrease with the electron-withdrawing ability of the 2-substituent, as indicated by Hammett sigma para values. Hydrogen peroxide consumption during the reaction is similar for the three phenothiazines. Denaturation reactions that occur upon exposure of methemoglobin to hydrogen peroxide have been investigated. For this heme-protein cross-linking was studied by means of heme retention by the protein after methyl ethyl ketone extraction. Furthermore, oxygen consumption during the reaction was assayed, which indicates formation of protein-peroxy radicals. The extent of both heme-protein cross-linking and oxygen consumption is decreased by phenothiazines in the same order as the phenothiazine conversion rate. CPZ sulfoxide is not converted by methemoglobin in the presence of hydrogen peroxide, and CPZ sulfoxide shows no effect on heme-protein cross-linking and oxygen consumption. The results are explained by electron transfer from phenothiazine to the protein radical. Stronger electron donors (MoPZ greater than CPZ greater than MaPZ) are converted faster and by reducing the protein radical they better protect hemoglobin against denaturation. A catalytic cycle, that takes into account our observation and the existing knowledge of hemoglobin oxidation states, is presented.

Oxidation of chlorpromazine by methemoglobin in the presence of hydrogen peroxide. Formation of chlorpromazine radical cation and its covalent binding to methemoglobin

The oxidation of chlorpromazine by methemoglobin plus H2O2 has been studied. The transient formation of the chlorpromazine radical cation in this reaction has been demonstrated by light absorption measurements. Under the experimental conditions complete conversion of chlorpromazine yields approximately 60% chlorpromazine sulfoxide. From studies with 3H-labeled chlorpromazine it appears that the remaining 40% is covalently bound to apohemoglobin. Upon reaction of methemoglobin with H2O2 a stable ferrylhemoglobin is formed. This ferrylhemoglobin is not the reactive species, which accepts the chlorpromazine electron, as its presence is not sufficient to induce chlorpromazine oxidation. For this the presence of H2O2 is a prerequisite. This indicates that a transient species in the formation of the stable ferrylhemoglobin is involved, whether this is a compound I analogue or a ferrylhemoglobin with a free radical on one of the apoprotein residues. Exposition of methemoglobin to H2O2 denatures hemoglobin and induces protein-heme crosslinks, as appears from changes in the visible absorption spectrum and heme retention by the protein after methyl ethyl ketone extraction. Reaction with CPZ partly protects against denaturation and crosslinking.

Metabolic activation of chlorpromazine by stimulated human polymorphonuclear leukocytes. Induction of covalent binding of chlorpromazine to nucleic acids and proteins

Human polymorphonuclear leukocytes (PMNs) have been stimulated with either phorbol 12-myristate 13-acetate (PMA), calcium ionophore A23187 or a combination of both to induce the respiratory burst and myeloperoxidase (MPO) release. Chlorpromazine (CPZ) but not chlorpromazine sulfoxide (CPZSO) inhibited the respiratory burst as measured with lucigenin chemiluminescence. The inhibition was due to interference with processes in the cell leading to the respiratory burst and not to scavenging of produced oxygen radicals that provoke the luminescence. CPZ was metabolized by stimulated PMNs. HPLC analysis revealed formation of CPZSO and an unidentified product. Both products result from decay of chlorpromazine radical cation (CPZ+.), indicating formation of this radical intermediate in CPZSO oxidation by stimulated PMNs. CPZ conversion correlated with H2O2 production and MPO release. The largest CPZ conversion was observed with phorbol ester plus A23187 stimulation. The conversion was reduced by catalase and sodium azide, an inhibitor of MPO, with 70% and 40%, respectively. This indicates only partial involvement of extracellularly released MPO in CPZ metabolism by PMNs. Considerable covalent binding of [3H]CPZ to nucleic acids and proteins of intact stimulated PMNs was observed. This binding was larger upon co-stimulation with phorbol ester and A23187. Azide did not reduce covalent binding. This indicates that covalent binding is not mediated by extracellularly released MPO and that CPZ is probably activated intracellularly. Activation of PMNs and production of H2O2 is a prerequisite for both CPZ conversion and covalent binding. This study demonstrates that phagocytic cells might contribute to drug metabolism and drug-induced toxicity.

Is hemoglobin a catalyst for sulfoxidation of chlorpromazine? An investigation with isolated purified hemoglobin and hemoglobin in monooxygenase and peroxidase mimicking systems

The possible role of hemoglobin in the sulfoxidation of chlorpromazine is still a controversial subject. Therefore this sulfoxidation was investigated with purified oxyhemoglobin and methemoglobin under various conditions: (i) in phosphate buffer pH 6.5; (ii) in monooxygenase mimicking systems with electron donors like ascorbic acid and NADPH, the last, with and without an electron carrier like methylene blue and cytochrome c reductase; (iii) in the presence of H2O2. Only in the presence of H2O2 chlorpromazine was converted into chlorpromazine sulfoxide in a considerable amount. This so-called peroxidase activity of hemoglobin appeared not to be based on a Fenton-type reaction. An oxidized reactive form of hemoglobin (i.e. ferrylhemoglobin) is responsible for the sulfoxidation. In the other systems only with ascorbic acid some chlorpromazine sulfoxide was produced. This is probably due to the production of H2O2 and the subsequent peroxidase activity of hemoglobin. Chlorpromazine enhanced the autoxidation of oxyhemoglobin, without being transformed itself.

Inhibition of the mutagenicity and metabolism of 6-methyl-benzo[a]pyrene and 6-hydroxymethyl-benzo[a]pyrene

Previously reported inhibitors of benzo[a]pyrene (BaP) mutagenicity in Salmonella typhimurium strain TA98 were tested for their effectiveness against the mutagenicity of 6-methyl-benzo[a]pyrene (6-CH3-BaP), 6-hydroxymethyl-benzo[a]pyrene (6-CH2OH-BaP) and 6-acetoxymethyl-benzo[a]pyrene (6-CH3COOCH2-BaP). Dose-response curves obtained for phenothiazine (PTH), 2-chlorophenothiazine (2Cl-PTH), phenylisothiocyanate (PHN), phenethylisothiocyanate (PNE), trans-retinol (TR) and disulfiram (TETD) showed a variety of degrees of inhibition of mutagenicity. Additionally, glutathione (GSH) was found to inhibit the mutagenicity of 6-CH3COOCH2-BaP, and the mutagenicity of 6-CH2OH-BaP was enhanced by the addition of supplemental ATP, Na2SO4 and EDTA. Only 2Cl-PTH was equally as good an inhibitor of 6-CH3-BaP and BaP, reducing revertant colonies to less than 50% of control at 10 X BaP concentration. To probe the mechanism of inhibition, the effect of 2Cl-PTH on the binding of BaP and the 6-substituted benzo[a]pyrenes to cytochrome P-450 was investigated by difference spectroscopy. Also, the effect of 2Cl-PTH on the subsequent metabolism of 6-CH3-BaP and 6-CH2OH-BaP was investigated by rapid scan difference spectroscopy and high-performance liquid chromatographic separation of products. The results are consistent with a major mechanism of inhibition for 2Cl-PTH involving a competition for the cytochrome P-450 binding site.

Degradation products of the promethazine radical cation

The degradation products of the promethazine radical cation, generated from promethazine with horseradish peroxidase/H2O2, have been investigated. Several products have been identified which resulted from fission of the bond between the two ethanamine carbon atoms of the N10 side chain. The main product (approx. 90%) was identified as 10-formyl-5-oxophenothiazine. The likely structure of three minor products was also elucidated. The degradation of the promethazine radical cation is different from that of radical cations derived from the propanamine side chain containing phenothiazine drugs.

Oxidative reactions of hydroxylated chlorpromazine metabolites

The oxidation pathways of two hydroxylated chlorpromazine metabolites were investigated using modern electrochemical techniques. Upon oxidation, the 7-hydroxy derivative of chlorpromazine rapidly reacts to form the 7,8-dihydroxy derivative and a substituted quinone. The oxidation potentials for both compounds were determined in the pH 3-8 range. The importance of these redox reactions and potentials to the pharmacology of the materials is discussed.

Reducing hospital readmission rates among schizophrenics

Most schizophrenics become in-patients in State mental hospitals, and most improve on neuroleptic medication and are rapidly discharged. The majority require long-term medication; the single most important factor in maintaining remission. This paper describes a mirror-image study using patients as their own controls, and demonstrates the highly significant differences in hospitalization before and after the administration of a depot phenothiazine. It highlights the need for vigorous and determined out-patient follow-up. It is suggested that the costs of an adequately staffed clinic are still small when compared with the costs of hospitalization. Subgroups of poor drug-responders, sex differences, variations in side effects and frequency of administration of the depot drug require further evaluation.

The distribution and metabolism of chlorpromazine in rats and the relationship to effects on cerebral monoamine metabolism

Rats were injected with chlorpromazine (CPZ), 21 mumoles/kg (7.5 mg/kg) i.p., and killed after different time intervals up to 24 h. Mass fragmentographic methods were used to determine the levels of CPZ, monodemethyl-chlorpromazine (nor1-CPZ) and 7-hydroxy-chlorpromazine (7-OH-CPZ) in brain and blood and dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA) and 5-hydroxy-3-indoleacetic acid (5-HIAA) in the striatum. Significant correlations between the brain and blood concentrations of CPZ as well as its active metabolites and the levels of DOPAC and HVA were obtained at several time points. The similarity between the time curves for CPZ dominantly the unchanged drug in the brain which determines the acceleration of DA metabolism.

A mirror image Out-patient study at a depot phenothiazine clinic

This Mirror Image Study, at a specialised clinic, has shown a significant reduction in days spent in Hospital. Individual features of the sample include sex and age difference in the sub-groups for dosage, duration of treatment and anti-Parkinsonian medication. Preliminary cost-effectiveness analysis has been reported.