Marrubium vulgare Extract Improves Spatial Working Memory and Oxidative Stress Damage in Scopolamine-Treated Rats

Putting Ethnobotany into Practice: In Vitro Antioxidant Potential and Impact on Rat Gastric Smooth Muscle Reactivity of Aqueous Extracts of Marrubium friwaldskyanum Boiss. and Marrubium peregrinum L

The genus Marrubium (Lamiaceae) is widely used in traditional medicine. While some representatives of the genus have been well investigated, the biological activity of others remains largely unknown. The aim of the current study was to assess the in vitro antioxidant potential and the effect on the reactivity of isolated rat gastric smooth muscles (SM) of aqueous extracts of Marrubium friwaldskyanum inflorescences, stems and leaves, and Marrubium peregrinum as a whole herb. The antioxidant activity was analyzed through multiple spectrophotometric and fluorometric assays. The effect on SM reactivity was determined by the treatment of excised gastric muscles of 10 male Whistar rats with the plant extracts alone or successive to 1,1-dimethyl-4-diphenylacetoxypiperidinium iodide, ketanserin, verapamil, and acetylcholine. According to the obtained results, the M. friwaldskyanum leaf extract exhibited the greatest antioxidant potential, followed by the M. peregrinum one. The SM reactivity analysis revealed that the treatment with all four extracts induced a dose-dependent contractile response with predominant cholinergic character. However, activation of serotoninergic and/or dopaminergic pathways was also observed. Furthermore, when applied after verapamil, the extracts showed a SM relaxant effect. The discovered biological activity will serve as a basis for future analyses through which the therapeutic effect of the plants will be investigated.

Resveratrol-Loaded Pluronic Micelles Ameliorate Scopolamine-Induced Cognitive Dysfunction Targeting Acetylcholinesterase Activity and Programmed Cell Death

Numerous experimental studies suggest the potential for resveratrol (RVT) to be useful in the Alzheimer's disease treatment, but its low bioavailability limits its application. This study aimed to assess the potential of resveratrol-loaded micelles as a neuronal delivery platform to protect rats from scopolamine-induced memory impairment. Resveratrol was incorporated into Pluronic micelles, and the effects of micellar (mRVT) and pure resveratrol (RVT) were compared in the model of scopolamine-induced dementia in male Wistar rats. Memory performance was assessed by a T maze test. The effect of the treatment on specific neurotransmitter levels and protein expression in the cortex and the hippocampus were evaluated biochemically. Our results revealed that the polymeric micelles were in nanoscale (approximately 33 nm) and reached 79% encapsulation efficiency. The treatment with mRVT demonstrated better spatial memory protective effect. The biochemical assays showed that mRVT in a dose of 10 mg/kg enhanced the effects of the pure drug in regard to noradrenalin neurotransmission and acetylcholinesterase inhibitory activity in the hippocampus. Furthermore, micellar resveratrol increased the cAMP-response element-binding protein expression in the cortex and hippocampus of rats as well as the Bcl2/BAX ratio, which indicated an anti-apoptotic effect in the experimental dementia model. In conclusion, our results indicated the potential of a micellar system loaded with resveratrol for neurodegenerative diseases treatment.

Neuroprotective Effect of Marrubium vulgare Extract in Scopolamine-Induced Cognitive Impairment in Rats: Behavioral and Biochemical Approaches

The potential of Marrubium vulgare to alleviate scopolamine (Sco)-induced deficits in spatial working memory has drawn considerable scientific interest. This effect is partly attributed to its potent antioxidant and acetylcholinesterase inhibitory (AChEI) activities. This study examined the effects of M. vulgare extract, standardized to marrubiin content, on recognition memory in healthy and Sco-treated rats. Male Wistar rats (200-250 g) were divided into four groups. The extract was orally administered for 21 days and Sco (2 mg/kg) was intraperitoneally injected for 11 consecutive days. Memory performance was assessed using the novel object recognition test. Levels of acetylcholine (ACh), noradrenaline (NA), serotonin (Sero), and brain-derived neurotrophic factor (BDNF) and the phosphorylation of cAMP response element-binding protein (p-CREB) were evaluated in the cortex and hippocampus via ELISA. BDNF and CREB expression levels were assessed using RT-PCR. The results showed that M. vulgare significantly alleviated Sco-induced memory impairment, preserved cholinergic function in the hippocampus, increased NA levels in the brain, and restored pCREB expression in the cortex following Sco-induced reduction. In healthy rats, the extract upregulated BDNF, pCREB, and Bcl2 expression. Our findings indicate that the neuroprotective effects of M. vulgare may be linked to the modulation of cholinergic function, regulation of NA neurotransmission, and influence on key memory-related molecules.