Atividade neuroprotetora do óleo de Cannabis rico em delta-9-tetraidrocanabinol (Δ9-THC) em modelo de epilepsia in vitro em linhagem celular do tipo SH-SY5Y

Abstract

The endocannabinoid system (ECS) is the main modulator of the central nervous system involved in synaptic plasticity processes and homeostatic events. Therefore, it has the ability to promote regulation in neurophysiological activities, including neurocognitive, nociceptive and mood processing. This mechanism occurs through the adjustment of the ECS in excitatory neurotransmission, especially in glutamatergic neurons. Excitotoxicity events mediated by Lglutamate are involved in different neuropathological conditions, such as neurodegenerative diseases and epilepsy. Nonclinical and clinical studies demonstrate that therapy with phytocannabinoids can generate improvements in the quality of life of patients, especially those suffering from disorders that do not respond to conventional therapy. Among them, we have patients with refractory epilepsy, an example of the observation in Dravet Syndrome and Lennox-Gastaut Syndrome. In the last decade, studies have emphasized a possible potentiation of pharmacological effects and reduction of side effects in cannabinoid therapy due to the entourage effect, which occurs through the synergy between phytocannabinoids, terpenes and flavonoids present in the Cannabis sativa plant. However, in vitro scientific evidence that reveals the pharmacological mechanisms that allow this synergism in neuroprotection needs to be better evaluated. Objectives: an in vitro investigation in a cellular model of epilepsy of the pharmacological mechanisms of full spectrum Cannabis oil rich in Δ9-THC in the excitotoxicity events induced by L-glutamate. Methodology: computational analysis in vitro silico culture of the SH-SY5Y cell line, cell procurement, Δ9-THC cytotoxicity assay, L-glut excitotoxicity assay and pharmacological blockers, analyzed through the tetrazolium salt reduction assay (MTT). Results: The study used the ProTox II tool to prevent Δ9-THC toxicity, showing an 84% probability of inactive cytotoxicity and 99% binding to mitochondrial membrane potential. In vitro analyses revealed that Δ9-THC increased cell coverage at low concentrations, with 88.92% survival at 0.5 μg/mL. When exposed to Lglutamate, cell options ranged from 86.04% to 96.47% with Δ9-THC, comparing neuroprotective effects. The CNQX and MK-801 blockers increased recommendations by up to 88.49%, evidencing the synergy between matter in modulating excitotoxicity. Conclusions: Δ9-THC presents cytotoxic and neuroprotective activity in vitro at low concentrations in the neuroblastoma cell line SH-SY5Y. Furthermore, the combination with the CNQX and MK-801 blockers potentiated the neuroprotective effects, possibly through action on CB1R receptors. Therefore, these findings are important for future research on new neuroprotective agents, more effective treatments for neuropathologies with neurotoxic effects.