The Effect of Prunus amygdalus var. amara Essential Oil on Suppressing Morphine-Induced Cell Death via Inhibition of Inflammatory Cytokines and Nitric Oxide Production

Objective: Elevated levels of morphine have been shown to promote cell death by enhancing cytotoxicity, as well as the production of nitric oxide (NO), inflammatory cytokines, and Caspase-3 within the central nervous system (CNS). The objective of this study was to investigate the inhibitory effects of essential oil derived from Prunus amygdalus var. amara on morphine-induced cell death in neuron-like PC12 cells. Material and Methods: Gas Chromatography Mass Spectroscopy (GC-MS) was employed for the chemical characterization of the essential oil derived from Prunus amygdalus var. amara. The assessment of cell viability, proliferation, and cytotoxicity was conducted using Trypan blue and lactate dehydrogenase (LDH) assays, respectively. DNA fragmentation was evaluated using the Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay. Nitric oxide production was quantified via the Griess reaction. The levels of inflammatory cytokines, specifically IL-1β, IL-6, INF-γ, and TNF-α, were measured using the Rat V-Plex Kit. Additionally, mitochondrial membrane potential was assessed with rhodamine-123, and Caspase-3 activity was determined using the Caspase-3 Colorimetric Assay Kit. Results: Gas chromatography-mass spectrometry analysis revealed that benzaldehyde and benzoic acid are the predominant chemical constituents present in the essential oil of Prunus amygdalus var. amara. Treatments utilizing the essential oil from Prunus amygdalus var. amara demonstrated enhanced cell proliferation and viability, alongside reduced cytotoxicity and cell death indices when compared to cells treated with morphine. Furthermore, the presence of Prunus amygdalus var. amara essential oil resulted in a decrease in the production of nitric oxide, interleukin-1 beta, interleukin-6, interferon-gamma, tumor necrosis factor-alpha, and Caspase-3, as well as a reduction in mitochondrial membrane potential. Conclusion: Our findings indicate that the essential oil derived from Prunus amygdalus var. amara effectively mitigates cell death induced by morphine in PC12 cells. This essential oil demonstrates the ability to inhibit nitric oxide (NO) production. Furthermore, it appears to impede apoptosis by inhibiting Caspase-3 activity, preventing DNA fragmentation, and disrupting the integrity of the mitochondrial membrane.