Detection of heroin metabolites at different developmental stages of Lucilia cuprina (Diptera: Calliphoridae) reared in heroin-treated meat: a preliminary analysis

Abstract

Background: Blowfly larvae and pupae collected during post-mortem forensic investigation can be analysed to detect drugs or toxins in a dead body. Drug or toxin-contaminated tissues of human remains consumed by blowfly larvae are stored in the crop even after a body has decomposed to the point where no fluid or tissues are retrievable. Therefore, blowfly larva and pupa are favourable specimens under conditions in which host tissues or blood samples are not available. Methodology: We carried out a study to detect heroin metabolites in Lucilia cuprina (Weidemann, 1830) immatures fed on different concentrations of heroin-treated meat: 500, 1000, 2500, 5000, and 10,000 ng/μl. Heroin metabolites detection was performed by a gas chromatography mass spectrophotometry (GCMS) analysis.Results: This study indicates that L. cuprina can be utilized in a toxicological analysis to detect heroin in a host. However, the expected complete metabolites of heroin were not detected in the first instar larvae and pupa, while the second and third instar larvae contributed to a complete heroin metabolite which was morphine. This was subject to the heroin concentration given. Morphine was detected in the third instar larvae treated with 5000 and 10,000 ng/μl heroin, while in the second instar, it was detected only at 10,000 ng/μl. Heroin metabolites detected in the second and third instar larvae proves that biochemical conversions occur in the fly larvae. Conclusion:The absence of heroin metabolites in the first instar larvae and pupa does not necessarily mean that the drug was not present in the host. Therefore, the limitations of heroin detection capability during these stages should be always kept in mind, as this could contribute to a false-negative result in a forensic analysis. If all stages are available during sample collection, it is crucial to prioritize the third instar larvae in a toxicological analysis.

Unexpected results found in larvae samples from two postmortem forensic cases

“…Several factors may influence the detectability of substances in larvae. The area of feeding and the developmental stage of the larvae [6,10,41] determine which substances they consume and the extent of their bioaccumulation in larvae. Moreover, the drug's pharmacokinetic behavior in both humans and larvae, as well as its physicochemical properties should be considered.…”

Entomotoxicología Forense En Cadáveres En Estado De Descomposición

“…The ecuador journal of medicine The ecuador journal of medicine lección de la muestra, es crucial priorizar las larvas del tercer estadio en un análisis toxicológico (33).…”

“…Sin embargo, los metabolitos completos esperados de la heroína no se detectaron en las larvas y pupas del primer estadio, mientras que las larvas del segundo y tercer estadio mostraron un metabolito completo de la heroína: la morfina (dependiente de la concentración de heroína dada). Los metabolitos de heroína detectados en el segundo y tercer estadio larvario probaron que se producen conversiones bioquímicas en las larvas de mosca (33).…”

Forensic analysis of mosquito blood meal digestion process and the impact of heroin opiate: determination of the post-feeding interval as a PMI estimation

“…GC–MS was used in this study because it has been successfully used for detecting heroin and its metabolites in insect tissues (Kintz et al 1990, Ishak et al 2019) and in human blood (Jones et al 2012). Samples were subjected to a series of processing steps for purifying heroin, as detailed in Andersen et al (2009).…”

“…The dry residues were then reconstituted with an ice-cold mobile phase (3% acetonitrile/97% 5 mM ammonium format buffer, pH 3.1), centrifuged, and transferred to the auto-sampler vials and used for GC–MS analysis. The qualitative analysis of heroin and its metabolites was carried out as detailed in Ishak et al (2019). The obtained results were analyzed using the National Institute of Standards and Technology (NIST) and Wiley MS libraries available on the GC–MS instrument.…”