Elevation of Pro-inflammatory and Anti-inflammatory Cytokines in Rat Serum after Acute Methamphetamine Treatment and Traumatic Brain Injury

The impact of psychostimulants on central and peripheral neuro-immune regulation: a scoping review of cytokine profiles and their implications for addiction

It is now well-accepted that psychostimulants act on glial cells causing neuroinflammation and adding to the neurotoxic effects of such substances. Neuroinflammation can be described as an inflammatory response, within the CNS, mediated through several cytokines, reactive oxygen species, chemokines and other inflammatory markers. These inflammatory players, in particular cytokines, play important roles. Several studies have demonstrated that psychostimulants impact on cytokine production and release, both centrally and at the peripheral level. Nevertheless, the available data is often contradictory. Because understanding how cytokines are modulated by psychoactive substances seems crucial to perspective successful therapeutic interventions, here, we conducted a scoping review of the available literature. We have focused on how different psychostimulants impact on the cytokine profile. Publications were grouped according to the substance addressed (methamphetamine, cocaine, methylphenidate, MDMA or other amphetamines), the type of exposure and period of evaluation (acute, short- or long-term exposure, withdrawal, and reinstatement). Studies were further divided in those addressing central cytokines, circulating (peripheral) levels, or both. Our analysis showed that the classical pro-inflammatory cytokines TNF-α, IL-6, and IL-1β were those more investigated. The majority of studies have reported increased levels of these cytokines in the central nervous system after acute or repeated drug. However, studies investigating cytokine levels during withdrawal or reinstatement have shown higher variability in their findings. Although we have identified fewer studies addressing circulating cytokines in humans, the available data suggest that the results may be more robust in animal models than in patients with problematic drug use. As a major conclusion, an extensive use of arrays for relevant cytokines should be considered to better determine which cytokines, upon the classical ones, may be involved in the progression from episodic use to the development of addiction. A concerted effort is still necessary to address the link between peripheral and central immune players, including from a longitudinal perspective. Until there, the identification of new biomarkers and therapeutic targets to envision personalized immune-based therapeutics will continue to be unlikely.

Intermittent theta burst stimulation to the left dorsolateral prefrontal cortex improves cognitive function in polydrug use disorder patients: a randomized controlled trial

Background

Polydrug abuse is common among opioid users. Individuals who use both heroin and methamphetamine (MA) have been shown to experience a wide range of cognitive deficits. Previous research shows that repetitive transcranial magnetic stimulation (rTMS) can change cerebral cortical excitability and regulate neurotransmitter concentration, which could improve cognitive function in drug addiction. However, the stimulation time, location, and possible mechanisms of rTMS are uncertain.

Methods

56 patients with polydrug use disorder were randomized to receive 20 sessions of 10 Hz rTMS (n = 19), iTBS (n = 19), or sham iTBS (n = 18) to the left DLPFC. All patients used MA and heroin concurrently. Cognitive function was assessed and several related proteins including EPI, GABA-Aα5, IL-10, etc. were quantified by ELISA before and after the treatment.

Results

Baseline RBANS scores were lower than normal for age (77.25; IQR 71.5-85.5). After 20 treatment sessions, in the iTBS group, the RBANS score increased by 11.95 (95% CI 0.02-13.90, p = 0.05). In particular, there were improvements in memory and attention as well as social cognition. Following treatment, serum EPI and GABA-Aα5 were reduced and IL-10 was elevated. The improvement of immediate memory was negatively correlated with GABA-Aα5 (r = -0.646, p = 0.017), and attention was positively correlated with IL-10 (r = 0.610, p = 0.027). In the 10 Hz rTMS group, the improvement of the RBANS total score (80.21 ± 14.08 before vs.84.32 ± 13.80 after) and immediate memory (74.53 ± 16.65 before vs.77.53 ± 17.78 after) was statistically significant compared with the baseline (p < 0.05). However, compared with the iTBS group, the improvement was small and the difference was statistically significant. There was no statistically significant change in the sham group (78.00 ± 12.91 before vs.79.89 ± 10.92 after; p > 0.05).

Conclusion

Intermittent theta burst stimulation to the left DLPFC may improve cognitive function in polydrug use disorder patients. Its efficacy appears to be better than that of 10 Hz rTMS. The improvement of cognitive function may be related to GABA-Aα5 and IL-10. Our findings preliminarily demonstrate the clinical value of iTBS to the DLPFC to augment neurocognitive recovery in polydrug use disorders.

Pharmacological components with neuroprotective effects in the management of traumatic brain injury: evidence from network meta-analysis

BACKGROUND

Neuroprotective drugs have been used to prevent secondary brain injury in patients with traumatic brain injury; however, the optimal medication remains questionable. We performed a Bayesian network meta-analysis to evaluate the safety and efficacy of different medications with known neuroprotective properties in this group of patients.

METHODS

Several databases were searched to identify any eligible trials comparing pharmacological components with confirmed neuroprotective mechanisms. Bayesian network meta-analysis was performed to combine direct and indirect evidence. The surface under the cumulative ranking curve was obtained to determine the ranking probability of the treatment agents for each outcome. The primary outcome was all-cause mortality.

RESULTS

A total of 23 trials comprising 4,325 participants were identified. The pooled relative risk (RR) showed administration of erythropoietin (RR: 0.68; 95% CrI: 0.50-0.93) and propranolol (RR: 0.43; 95% CrI: 0.20-0.85) decreased all-cause mortality compared with placebo. We also found erythropoietin (RR: 1.55; 95% CrI: 1.03-2.35), propranolol (RR: 1.52; 95% CrI: 1.05-2.20), and progesterone (RR: 1.47; 95% CrI: 1.03-2.10) showed better efficacy in functional recovery.

CONCLUSION

Overall, erythropoietin and propranolol were associated with reduced mortality in adults with traumatic brain injury. These treatment agents were also associated with improved functional outcomes.

Role of Microglia in Psychostimulant Addiction

The use of psychostimulant drugs can modify brain function by inducing changes in the reward system, mainly due to alterations in dopaminergic and glutamatergic transmissions in the mesocorticolimbic pathway. However, the etiopathogenesis of addiction is a much more complex process. Previous data have suggested that microglia and other immune cells are involved in events associated with neuroplasticity and memory, which are phenomena that also occur in addiction. Nevertheless, how dependent is the development of addiction on the activity of these cells? Although the mechanisms are not known, some pathways may be involved. Recent data have shown psychoactive substances may act directly on immune cells, alter their functions and induce various inflammatory mediators that modulate synaptic activity. These could, in turn, be involved in the pathological alterations that occur in substance use disorder. Here, we extensively review the studies demonstrating how cocaine and amphetamines modulate microglial number, morphology, and function. We also describe the effect of these substances in the production of inflammatory mediators and a possible involvement of some molecular signaling pathways, such as the toll-like receptor 4. Although the literature in this field is scarce, this review compiles the knowledge on the neuroimmune axis that is involved in the pathogenesis of addiction, and suggests some pharmacological targets for the development of pharmacotherapy.

Nanowired Delivery of Curcumin Attenuates Methamphetamine Neurotoxicity and Elevates Levels of Dopamine and Brain-Derived Neurotrophic Factor

Curcumin is a well-known antioxidant used as traditional medicine in China and India since ages to treat variety of inflammatory ailments as a food supplement. Curcumin has antitumor properties with neuroprotective effects in Alzheimer's disease. Curcumin elevates brain-derived neurotrophic factor (BDNF) and dopamine (DA) levels in the brain indicating its role in substance abuse. Methamphetamine (METH) is one of the most abused substances in the world that induces profound neurotoxicity by inducing breakdown of the blood-brain barrier (BBB), vasogenic edema and cellular injuries. However, influence of curcumin on METH-induced neurotoxicity is still not well investigated. In this investigation, METH neurotoxicity and neuroprotective effects of curcumin nanodelivery were examined in a rat model. METH (20 mg/kg, i.p.) neurotoxicity is evident 4 h after its administration exhibiting breakdown of BBB to Evans blue albumin in the cerebral cortex, hippocampus, cerebellum, thalamus and hypothalamus associated with vasogenic brain edema as seen measured using water content in all these regions. Nissl attaining exhibited profound neuronal injuries in the regions of BBB damage. Normal curcumin (50 mg/kg, i.v.) 30 min after METH administration was able to reduce BBB breakdown and brain edema partially in some of the above brain regions. However, TiO₂ nanowired delivery of curcumin (25 mg/kg, i.v.) significantly attenuated brain edema, neuronal injuries and the BBB leakage in all the brain areas. BDNF level showed a significant higher level in METH-treated rats as compared to saline-treated METH group. Significantly enhanced DA levels in METH-treated rats were also observed with nanowired delivery of curcumin. Normal curcumin was able to slightly elevate DA and BDNF levels in the selected brain regions. Taken together, our observations are the first to show that nanodelivery of curcumin induces superior neuroprotection in METH neurotoxicity probable by enhancing BDNF and DA levels in the brain, not reported earlier.

Methamphetamine induced neurotoxic diseases, molecular mechanism, and current treatment strategies

Methamphetamine (MA) is a extremely addictive psychostimulant drug with a significant abuse potential. Long-term MA exposure can induce neurotoxic effects through oxidative stress, mitochondrial functional impairment, endoplasmic reticulum stress, the activation of astrocytes and microglial cells, axonal transport barriers, autophagy, and apoptosis. However, the molecular and cellular mechanisms underlying MA-induced neurotoxicity remain unclear. MA abuse increases the chances of developing neurotoxic conditions such as Parkinson's disease (PD), Alzheimer's disease (AD) and other neurotoxic diseases. MA increases the risk of PD by increasing the expression of alpha-synuclein (ASYN). Furthermore, MA abuse is linked to high chances of developing AD and subsequent neurodegeneration due to biological variations in the brain region or genetic and epigenetic variations. To date, there is no Food and Drug Administration (FDA)-approved therapy for MA-induced neurotoxicity, although many studies are being conducted to develop effective therapeutic strategies. Most current studies are now focused on developing therapies to diminish the neurotoxic effects of MA, based on the underlying mechanism of neurotoxicity. This review article highlights current research on several therapeutic techniques targeting multiple pathways to reduce the neurotoxic effects of MA in the brain, as well as the putative mechanism of MA-induced neurotoxicity.

State-of-the-Art on Wound Vitality Evaluation: A Systematic Review

The vitality demonstration refers to determining if an injury has been caused ante- or post-mortem, while wound age means to evaluate how long a subject has survived after the infliction of an injury. Histology alone is not enough to prove the vitality of a lesion. Recently, immunohistochemistry, biochemistry, and molecular biology have been introduced in the field of lesions vitality and age demonstration. The study was conducted according to the preferred reporting items for systematic review (PRISMA) protocol. The search terms were "wound", "lesion", "vitality", "evaluation", "immunohistochemistry", "proteins", "electrolytes", "mRNAs", and "miRNAs" in the title, abstract, and keywords. This evaluation left 137 scientific papers. This review aimed to collect all the knowledge on vital wound demonstration and provide a temporal distribution of the methods currently available, in order to determine the age of lesions, thus helping forensic pathologists in finding a way through the tangled jungle of wound vitality evaluation.