Myristica fragrans seed extract reverses scopolamine-induced cortical injury via stimulation of HO-1 expression in male rats

Myristica fragrans, commonly known as nutmeg, belongs to the Myristicaceae family and is used as a spice and for its medicinal properties. The purpose of this study was to assess the neuroprotective effect of M. fragrans seed methanolic extract (MFE) on scopolamine-induced oxidative damage, inflammation, and apoptosis in male rat cortical tissue. MFE or N-acetylcysteine (NAC), a standard antioxidant drug, was administered 7 days before treatment with scopolamine resulted in high levels of malondialdehyde and nitric oxide (oxidative stress biomarkers), tumor necrosis factor-alpha and interleukin-1 beta (inflammatory mediators), and Bax and caspase-3 pro-apoptotic proteins. Additionally, scopolamine significantly depleted levels of glutathione (an antioxidant marker), Bcl-2 and c-FLIP (anti-apoptotic proteins), and antioxidant enzymes activity in cortical tissue. Scopolamine also enhanced acetylcholinesterase activity. MFE treatment protected the cortex of rats from the effects of scopolamine by reversing the effects on these toxicity markers. Interestingly, the neuroprotective effect of MFE was comparable to that exerted by the reference antioxidant NAC. Thus, our findings show that MFE has antioxidant, anti-inflammatory, and anti-apoptotic effects. The beneficial effects of MFE on scopolamine were partially mediated by promoting heme oxygenase 1 (Hmox1) expression and preserving cortical tissue structure.