The psychoactive drug 25B-NBOMe recapitulates rhabdomyolysis in zebrafish larvae

Abstract

N-Benzyl-substituted 2C class phenethylamines (NBOMes) are psychoactive designer drugs, with strong hallucinogenic and stimulant effects, even at low doses. The designer drug, 2-(4-bromo-2, 5-dimethoxyphenyl)-N-(2-methoxybenzyl) ethanamine (25B-NBOMe) is considered to be one of the most potent agonists of the serotonin-2A (5-HT2A) receptor. Recently, we reported the first lethal case of 25B-NBOMe intoxication with severe rhabdomyolysis, concluded by clinical, pathological and toxicological analyses. There are currently no good animal models that closely recapitulate serotonin receptor-dependent rhabdomyolysis. In the present study, we created animal models of rhabdomyolysis using zebrafish larvae to study the pathomechanism of rhabdomyolysis, and demonstrated that 25B-NBOMe can simulate lethal rhabdomyolysis in this animal. Treatment of the larvae with 25B-NBOMe decreased their survival rate, locomotion, altered birefringence of the skeletal muscle and immunostainings for dystroglycan (a myoseptal protein) and myosin heavy chain (a myofibril protein), which were consistent with rhabdomyolysis. This 25B-NBOMe-induced rhabdomyolysis was inhibited by the 5-HT2A receptor antagonists ritanserin and aripirazole, but not by the 5-HT1A + 5-HT1B receptor antagonist propranolol and the 5-HT3 receptor antagonist granisetron, indicating 5-HT2A-dependent rhabdomyolysis. The 25B-NBOMe-treated zebrafish is, therefore, a highly useful model of rhabdomyolysis for studying the pathomechanism of rhabdomyolysis as well as for therapeutic drug screening.

Zebrafish and Artemia salina in vivo evaluation of the recreational 25C-NBOMe drug demonstrates its high toxicity

“…In humans, it also includes mental status changes. In agreement with Kawahara et al (2017) the NBOMe compounds, which are serotonergic drugs, could induce effects associated with this syndrome caused mainly by excessive activation of serotonin receptors [ 4 ].…”

“…Our data in zebrafish embryos exposed to 25C-NBOMe show an LC 50 value of 10.76 μg/mL. Studies with other NBOMe family members have shown a reduction in the survival rate of approximately 40 %, for the concentration of 0.5 μg/mL for 25B-NBOMe [ 4 ]. However, this exposure was only done starting at 4 dpf by Kawahara et al (2017).…”

“…Although the 5-HT 2A receptor gene has been duplicated in a teleost, it retains its functions as observed in mammals. It shows similar expression patterns in smooth muscle fibers, skeletal muscle, endothelial cells, frontal cortex, basal ganglia, and the synaptic cleft [ 4 ], [ 26 ].…”

“…For the determination of the LC 50 in zebrafish we used the Test Guidelines for the Chemicals - Fish Embryo Toxicity Test (FET) for zebrafish ( Danio rerio ) proposed by Organisation for Economic Co-operation and Development (OECD - July 26, 2013) and the previous study of Kawahara et al [ 4 , 20 ].…”

“…Some aspects of the toxic effect of 25B-NBOMe like survival rate and the muscle effects have been evaluated but no study has been made for any other derivatives [ 4 ]. Specifically, 25C-NBOMe is under investigation due to adverse reactions attributed to it, such as sublingual numbness, levitation perception, involuntary motor activity, psychedelic effects, rhabdomyolysis, cardiac function problems, and, in some cases, death.…”