However, there are currently no published behavioral studies that have directly assessed the potential abuse liability of α-PVP and 4-MEC. Thus, the current study sought to determine the effects of α-PVP and 4-MEC, along with methamphetamine for comparison, on thresholds for intracranial self-stimulation (ICSS) using a discrete trials current threshold determination procedure (Markou and Koob, 1992). Using a discrete trials current intensity threshold intracranial self-stimulation procedure, the present study assessed the effects of 2 common second-generation synthetic cathinones, α‐pyrrolidinopentiophenone (0.1–5mg/kg) and 4-methyl-N-ethcathinone (1–100mg/kg) on brain reward function. PV9 and its substituted analogs produced significant cytotoxicity in all analyzed cell lines, with profound effects observed after 24 h incubation at concentrations of 200 and 300 μM (Fig. 6). Treatment with PV9 for 24 h caused a significant decrease in the survival of Hep G2 and RPMI 2650 (10–300 μM), SH-SY5Y (100–300 μM), and H9c2(2-1) (200 and 300 μM) cells. Cell viability was reduced to below 30% of the control group values by 200 and 300 μM PV9 in Hep G2 (max. reduction by 91%) and RPMI 2650 cells (max. reduction by 96%), and by 300 μM PV9 in SH-SY5Y (max. reduction by 81%) and H9c2(2-1) cells (max. reduction by 89%) (Fig. 6a).

• The result of the cellular products and proteins released during rhabdomyolysis and dehydration can impair the filtering function of the kidneys, leading to renal failure and death.
• Neurotransmitter levels were measured to investigate if neuronal signaling changed as a function of duration of synthetic cathinone exposure and modeled different stages of drug abuse (Koob and Volkow, 2010).
• Once a person who has misused Flakka is in a state where they are not a danger to themselves and others, a full diagnosis and course of treatment can be prescribed by a clinician or doctor.
• Thus, the current study sought to determine the effects of α-PVP and 4-MEC, along with methamphetamine for comparison, on thresholds for intracranial self-stimulation (ICSS) using a discrete trials current threshold determination procedure (Markou and Koob, 1992).
• Bath salts, in general, are psychoactive synthetic drugs (designer drugs) made in large quantities in foreign drug labs.
• Internationally, the legal status of flakka varies by country, but many countries have taken steps to control its use due to its dangerous effects.

It may be mixed with or sold as other illicit substances ranging from cocaine to ecstasy, LSD, methamphetamine, and more. Flakka only arrived on the drug market in the mid-2000s and has since become a significant threat to public health in many areas of Florida, and Broward County in particular. A hit of cocaine, when snorted, usually lasts around 30 minutes; a hit of Flakka can last for up to five hours. Some Flakka abusers have reported dissociative feelings similar to those felt when abusing benzodiazepines or hallucinogens such as ketamine. The epicenter of the flakka epidemic was Broward County, Florida, which includes the city of Fort Lauderdale.

Short-Term Effects Of Flakka Use

Self-administration of alpha-pyrrolidinopentiophenone function either synthetic cathinone also increased NE levels in several brain regions, with the biggest increases shown in hypothalamus. Synthetic cathinone self-administration also altered GLU levels compared to naïve in select brain regions, but the magnitude and direction of effects varied by synthetic cathinone. In addition to the observed changes in neurotransmitter levels, there were several interesting changes in neurotransmitter to metabolite ratios based on duration of drug exposure.

Treatment for Flakka abuse

• In SH-SY5Y neuroblasts, only 4-F-PVP and 4-MeO-PVP used at 300 μM caused a slight elevation of extracellular LDH activity.
• Despite these challenges, flakka holds promise in neuroscience research and potential therapeutic applications.
• Since 2008, each year has seen the introduction of a number of novel synthetic cathinone derivatives into the dynamic, clandestine NPS market, in an attempt to circumvent legal restrictions (EMCDDA 2017; Majchrzak et al. 2018; Zawilska and Wojcieszak 2017).
• Importantly, the more lipophilic PV8 and PV9 evoked changes in the membrane fluidity across a broader concentration range than PVP, an observation that is in line with the fact that disturbances were found in the internal, highly lipophilic part of the membrane but not in the external polar head-groups.
• The desired psychostimulatory effects include raised alertness and awareness, improved mood, impression of increased motivation, energy, and euphoria (Zawilska and Wojcieszak 2017).

Self-administration of α-PVP and 4MMC induced plasticity in neural circuitry that may be driving compulsive drug taking or producing a deficit state for normal reward, thereby increasing motivation to continue self-administration (Koob and Le Moal, 2005). Furthermore, the increased GLU levels observed for LgA groups may be enhancing drug seeking (Koob, 2010), although drug seeking was not directly measured in the present study. Cocaine and amphetamine, which have similar mechanisms of action as α-PVP and 4MMC, respectively, induce synaptic plasticity within the DA system and DA receptive neurons.

Effects of PV8, 4-F-PV8, and 4-MeO-PV8 on the Survival of SH-SY5Y, Hep G2, RPMI 2650, and H9c2(2- Cells

This includes feelings of euphoria, heightened focus, increased sex drive, and being sociable. When Flakka is abused in high amounts it can cause users to have paranoid, violent, and bizarre behavior, again similar to bath salt abuse. In the United States, flakka is classified as a Schedule I controlled substance under the Controlled Substances Act. Schedule I drugs are defined as substances with a high potential for abuse, no currently accepted medical use in treatment, and a lack of accepted safety for use under medical supervision. Our findings are in line with those published by Matsunaga et al. (2017), demonstrating that cytotoxicity of pyrovalerones increases with the elongation of the α-carbon side-chain.

Figure 1.

Flakka was added to the Schedule I list in 2014 by the Drug Enforcement Administration (DEA). This was part of an effort to curb the abuse of synthetic drugs, which were becoming increasingly popular and causing significant health issues. Exposure of Hep G2 cells to PVP, PV8, and PV9 for 15 min significantly lowered the fluorescence anisotropy of the DPH probe, which is negatively related to the fluidity of the inner part of the cell membrane. Statistically significant increases in membrane fluidity were observed in the concentration range from 50 to 300 μM for PVP and 25 to 300 μM for PV8 and PV9, while the most pronounced effect was observed after treatment with PV8 (300 μM) (Fig. 8). However, neither PVP, PV8, or PV9 lowered the fluorescence anisotropy of the TMA-DPH probe, which reflects the fluidity of the polar head-group portion of the cell membrane (Fig. 8). Hep G2 and H9c2(2-1) cells were cultivated in DMEM, SH-SY5Y in DMEM/F12, and RPMI 2650 in MEM with Earle’s salts and 1× Non-Essential Amino Acids Solution media, supplemented with 10% fetal bovine serum (FBS) and penicillin (100 U/ml)-streptomycin (100 μg/ml) at 37 °C in a humidified atmosphere enriched with 5% CO2.

Long incubation times were applied in order to show whether the cytotoxicity of studied compounds increase with time, which is relevant since the common abuse pattern of synthetic cathinones includes long sessions during which multiple doses are administered (Zawilska and Wojcieszak 2013). The effects of α-PPP on serotonin levels are somewhat surprising, as it has reported selectivity for the dopamine and norepinephrine transporters over the serotonin transporter (Eshleman et al. 2017). However, we used a relatively high dose regimen to ensure near maximal levels of toxicity, and α-PPP likely loses some selectivity at such doses.

Cedrick Maceo Daphney

Furthermore, data for several neurotransmitter levels were similar across groups, despite the analyses being conducted at different times. Thus, it is unlikely that the timing of the analyses caused differences in neurotransmitter levels. Another limitation was that only one self-administration dose of α-PVP and 4MMC was included. Although the doses were located at similar points on the dose-effect curves (Aarde et al., 2015; Gannon et al., 2017; Nguyen et al., 2016), it is unknown if the results of this study will generalize across doses. In contrast to the minor sex differences in self-administration behavior, sex differences in neurochemical changes were more widespread. Notably, sex differences in neurochemistry were more abundant for ShA than LgA groups, and the cause of this is unknown.

The report demonstrates, for the first time, that changes of fluidity of the interior part of plasma membrane contribute to the cytotoxicity of pyrovalerone derivatives, in addition to the previously reported mechanisms. As with neurochemistry, there has been little study of the persistent effects of synthetic cathinone exposure on learning, memory, and behavior. A recent study examined the effects of binge-like self-administration of MDPV using five 96-hour self-administration sessions in rats. Three weeks after the last session, the subjects showed both neurodegeneration and deficits in NOR performance (Sewalia et al. 2018). We report that, five days after exposure to α-PPP, mice exhibited decreased exploratory behavior as well as significantly impaired Y-maze performance.

Drug concentrations used in this in vitro study, reaching 300 μM, exceed those normally found in the blood obtained from intoxicated patients and during autopsies (Kudo et al. 2015; Marinetti and Antonides 2013). However, as discussed in our previous work (Wojcieszak et al. 2016), organs such as the liver, brain, and upper airway epithelium can be exposed to significantly higher local drug concentrations than those measured in blood. Moreover, it is noteworthy that immortalized cancer cell lines, which are a convenient model for in vitro studies, can be more resistant to cytotoxicity, and therefore, cell damage can be observed in concentrations higher than in normal cells in vivo (den Hollander et al. 2014; Wojcieszak et al. 2016).