Oxidative stress in opium users after using lead-adulterated opium: The role of genetic polymorphism

Sinapic acid protects against lead acetate-induced lung toxicity by reducing oxidative stress, apoptosis, inflammation, and endoplasmic reticulum stress damage

Lead acetate (PbAc) is a compound that produces toxicity in many tissues after exposure. Sinapic acid (SNP) possesses many biological and pharmacological properties. This study aimed to investigate the efficacy of SNP on the toxicity of PbAc in lung tissue. PbAc was administered orally at 30 mg/kg and SNP at 5 or 10 mg/kg for 7 days. Biochemical, genetic, and histological methods were used to investigate inflammatory, apoptotic, endoplasmic reticulum stress, and oxidative stress damage levels in lung tissue. SNP administration induced PbAc-reduced antioxidant (GSH, SOD, CAT, and GPx) and expression of HO-1 in lung tissue. It also reduced MDA, induced by PbAc, and thus alleviated oxidative stress. SNP decreased the inflammatory markers NF-κB, TNF-α and IL-1β levels induced by PbAc in lung tissue and exhibited anti-inflammatory effect. PbAc increased apoptotic Bax, Apaf-1, and Caspase-3 mRNA transcription levels and decreased anti-apoptotic Bcl-2 in lung tissues. SNP decreased apoptotic damage by reversing this situation. On the other hand, SNP regulated these markers and brought them closer to the levels of the control group. PbAc caused prolonged ER stress by increasing the levels of ATF6, PERK, IRE1α, GRP78 and this activity was stopped and tended to retreat with SNP. After evaluating all the data, While PbAc caused toxic damage in lung tissue, SNP showed a protective effect by reducing this damage.

Lead poisoning among asymptomatic individuals with a long-term history of opiate use in Golestan Cohort Study

BACKGROUND

Recent reports of lead poisoning suggest that people who use opium may be exposed to high amounts of lead. Here, we investigate the association between opium use and blood lead levels (BLL) in a population-based cohort study.

METHODS

In 2017, we studied a random sample of 410 people who currently (both within the past year and the past month) used opium and 104 who did not from participants of the Golestan Cohort Study in northeast Iran. Participants were stratified by sex and tobacco use history, completed a comprehensive opiate and tobacco use questionnaire and provided blood. BLL was measured by Lead Care® II Blood Lead Test Kit, validated by inductively coupled plasma triple quadrupole mass spectrometry. BLL was categorized as "<5 µg/dL", "elevated" (5-10 µg/dL), "high" (10-50 µg/dL), and "very high" (above 50 µg/dL). To assess the association between BLL categories and opiate use, route of consumption and weekly use, we used ordered logistic regression models, and report OR (odds ratio) and 95% CI (confidence interval) adjusted for age, sex, place of residence, education, occupation, household fuel type, and tobacco use.

RESULTS

In the cohort, participants used only raw (teriak) or refined (shireh) opium, which were smoked (45%, n = 184), taken orally (46%, n = 189), or both (9%, n = 37), for a mean duration of 24.2 (standard deviation: 11.6) years. The median BLL was significantly higher in people who currently used opium (11.4 µg/dL; IQR: 5.2-23.4) compared with those who did not (2.3 µg/dL; IQR: 2.3-4.2), and the highest median BLL was seen in oral use (21.7 µg/dL; IQR: 12.1-34.1). The BLL was <5 µg/dL among 79.8% of people with no opiate use, compared with only 22.7% in those using opium. BLL was elevated in 21.7%, high in 50.5% and very high in 5.1% of people using opium. About 95% of those with oral (180/189) or dual use (35/37) and 55% (102/184) of those who smoked opium had levels of blood lead above 5 µg/dL. The OR for the association between any opium use and each unit of increase in BLL category was 10.5 (95%CI: 5.8-19.1), and oral use of opium was a very strong predictor of increasing BLL category (OR=74.1; 95%CI: 35.1-156.3). This odds ratio was 38.8 (95%CI: 15.9-95.1) for dual use and 4.9 (95%CI: 2.6-9.1) for opium smoking. There was an independent dose-response association between average weekly dose and BLL among people using opium, overall and when stratified by route of use.

CONCLUSION

Our results indicate that regular use of lead-adulterated opium can expose individuals to high levels of lead, which may contribute to mortality and cancer risks associated with long-term opium use.

Protective Effects of Chrysin Against Oxidative Stress and Inflammation Induced by Lead Acetate in Rat Kidneys: a Biochemical and Histopathological Approach

In this study, the protective effects of chrysin (CR) on lead acetate (PbAc)-induced renal toxicity in Sprague-Dawley rats were investigated with biochemical, histopathological, and immunohistochemical methods. In the study, rats were given orally at 30 mg/kg/body weight (BW) PbAc after CR of 25 and 50 mg/kg/BW was administered to them orally (a total of 7 administrations for 7 days). The results showed that CR reduced urea and creatinine levels by alleviating PbAc-induced kidney damage. It was determined that CR decreases PbAc-induced lipid peroxidation due to its antioxidant properties and increases catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx) activities, and glutathione (GSH) levels. It was also detected that CR protects DNA from the toxic effects of PbAc and reduces 8-hydroxy-2'-deoxyguanosine (8-OHdG) levels. Biochemical and immunohistochemical findings demonstrated that CR had anti-inflammatory and antiapoptotic effects and reduced nuclear factor kappa-B (NF-κB), interleukin-33 (IL-33), prostaglandin-E2 (PGE-2), tumor necrosis factor-α (TNF-α), p53 levels, and the activities of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS), which were increased with PbAc administration. Moreover, CR was found to increase the levels of aquaporin-1 (AQP-1) and nephrine in PbAc-induced kidney tissue. CR decreased the contents of lead (Pb), zinc (Zn), iron (Fe), sodium (Na), and copper (Cu) and increased those of potassium (K) calcium (Ca) in renal tissue. These results indicated that CR considerably alleviates kidney toxicity caused by PbAc.

Viral vector-mediated gene therapy for opioid use disorders

Chronic exposure to opioids typically results in adverse consequences. Opioid use disorder (OUD) is a disease of the CNS with behavioral, psychological, neurobiological, and medical manifestations. OUD induces a variety of changes of neurotransmitters/neuropeptides in the nervous system. Existing pharmacotherapy, such as opioid maintenance therapy (OMT) is the mainstay for the treatment of OUD, however, current opioid replacement therapy is far from effective for the majority of patients. Pharmacological therapy for OUD has been challenging for many reasons including debilitating side-effects. Therefore, developing an effective, non-pharmacological approach would be a critical advancement in improving and expanding treatment for OUD. Viral vector mediated gene therapy provides a potential new approach for treating opioid abused patients. Gene therapy can supply targeting gene products directly linked to the mechanisms of OUD to restore neurotransmitter and/or neuropeptides imbalance, and avoid the off-target effects of systemic administration of drugs. The most commonly used viral vectors in rodent studies of treatment of opioid-used disorder are based on recombinant adenovirus (AV), adeno-associated virus (AAV), lentiviral (LV) vectors, and herpes simplex virus (HSV) vectors. In this review, we will focus on the recent progress of viral vector mediated gene therapy in OUD, especially morphine tolerance and withdrawal.

MOLECULAR MECHANISMS OF LEAD NEUROTOXICITY

Lead (Pb2+) is a non-essential metal with numerous industrial applications that have led to ts ubiquity in the environment. Thus, not only occupational-exposed individuals' health is compromised, but also that of the general population and in particular children. Notably, although the central nervous system is particularly susceptible to Pb2+, other systems are affected as well. The present study focuses on molecular mechanisms that underlie the effects that arise from the presence of Pb2+ in situ in the brain, and the possible toxic effects that follows. As the brain barriers represent the first target of systemic Pb2+, mechanisms of Pb2+ entry into the brain are discussed, followed by a detailed discussion on neurotoxic mechanisms, with special emphasis on theories of ion mimicry, mitochondrial dysfunction, redox imbalance, and neuroinflammation. Most importantly, the confluence and crosstalk between these events is combined into a cogent mechanism of toxicity, by intertwining recent and old evidences from humans, in vitro cell culture and experimental animals. Finally, pharmacological interventions, including chelators, antioxidants substances, anti-inflammatory drugs, or their combination are reviewed as integrated approaches to ameliorate Pb2+ harmful effects in both developing or adult organisms.

Lead poisoning associated with illicit opium use

Lead poisoning is an uncommon and challenging diagnosis to make. In 2018, The Victorian Department of Health issued a health warning following four cases of lead poisoning associated with illicit opium use in Melbourne, Australia. We present these cases to highlight clinical features and the relevant investigations leading to diagnosis. All cases occurred in recent immigrants to Australia, who had access to non-traditional sources of opioids. Health care professionals should consider lead poisoning in patients with appropriate symptoms and a history of illicit opium use.

The effects of functionalization of carbon nanotubes on toxicological parameters in mice

Carbon nanotubes (CNTs) have emerged as a new class of multifunctional nanoparticles in biomedicine, but their multiple in vivo effects remain unclear. Also, the impact of various functionalization types and duration of exposures are still unidentified. Herein, we report a complete toxicological study to evaluate the effects of single- and multiwalled carbon nanotubes (SWCNTs and MWCNTs) with either amine or carboxylic acid (COOH) surface functional groups. The results showed that significant oxidative stress and the subsequent cell apoptosis could be resulted in both acute and, mainly, in chronic intravenous administrations. Also, male reproductive parameters were altered during these exposures. The amino-functionalized CNTs had more toxic properties compared with the COOH functionalized group, and also, in some groups, the multiwalled nanotubes were more active in eliciting cytotoxicity than the single-walled nanotubes. Interestingly, the SWCNTs-COOH had the least alterations in most of the parameters. Evidently, it is concluded that the toxicity of CNTs in specific organs can be minimized through particular surface functionalizations.

Homogeneous liquid–liquid microextraction based on liquid nitrogen-induced phase separation followed by GFAAS for sensitive extraction and determination of lead in lead-adulterated opium and refined opium

Herein, we developed a novel homogeneous liquid–liquid microextraction based on liquid nitrogen-induced phase separation (HLLME-LNPS) for the extraction and determination of lead (Pb) in Pb-adulterated opium and refined opium by GFAAS analysis. In this procedure, first, 400 μl of acetonitrile (extractant) containing 7.0 μl of diethyl dithiophosphoric acid (DDTP) is injected into a sample solution and a homogeneous solution is formed. Subsequently, the homogeneous mixture is cooled using liquid nitrogen for 16 seconds. By this process, due to the difference in the freezing points of the organic and aqueous phases, the homogeneous state is broken and the Pb-DDTP species are extracted into the liquid organic phase collected on top of the frozen aqueous phase. The introduced method exhibited a good linearity with a coefficient of determination (r²) of 0.9988 and an acceptable linear range of 0.6–100 μg l⁻¹. Accordingly, the detection limit was 0.2 μg l⁻¹ (S/N = 3) for Pb ions, and a high enrichment factor was obtained. The proposed method was successfully utilized to determine trace levels of Pb in opium samples. The results of the sample analysis showed that 65% of the opium samples and 85% of the refined opium samples had much higher than expected levels of contaminating Pb, and this contamination poses a serious threat to drug users.

Herein, we developed a novel homogeneous liquid–liquid microextraction based on liquid nitrogen-induced phase separation (HLLME-LNPS) for the extraction and determination of lead (Pb) in Pb-adulterated opium and refined opium by GFAAS analysis.