Angelica purpurascens (Avé-Lall.) Gilli. Essential Oil Improved Brain Function via Cholinergic Modulation and Antioxidant Effects in the Scopolamine-Induced Zebrafish (Danio rerio) Model

Angelica purpurascens (Avé-Lall.) Gilli. is a medicinal plant that displays antioxidant, anticholinesterase, and neuroprotective properties. The effect of A. purpurascens essential oil (APO) on memory impairments and brain oxidative stress in zebrafish (Danio rerio) treated with scopolamine (Sco), as well as the underlying mechanism involved, were investigated in this study. Exposure to Sco (100 μM) resulted in anxiety in zebrafish, as assessed by the novel tank diving test (NTT), whereas spatial memory and novelty response dysfunctions, as evidenced by the Y-maze test and novel object recognition test (NOR), were noticed. When zebrafish were given Sco and simultaneously given APO (25 and 150 μL/L, once daily for 13 days), the deficits were averted. An increase in brain antioxidant enzymes, a reduction of lipid peroxidation, and protein oxidation were linked to this impact. Furthermore, acetylcholinesterase (AChE) activity was significantly reduced in the brains of APO-treated zebrafish. The main detected components in the APO composition were β-phellandrene (33.80%), sabinene (6.80%), α-pinene (5.30%), germacrene-D (4.50%), α-phellandrene (4.20%), and p-cymene (3.80%) based on gas chromatography–mass spectrometry (GC-MS) investigations. Our findings show that APO’s beneficial effect in a zebrafish model of Sco-induced memory impairment is mediated through multiple mechanisms, including the restoration of cholinergic system function and the improvement of the brain antioxidant state. As a result, APO could be employed as a potential source of bioactive molecules with useful biological properties and medicinal uses

TIME DEPENDENT ACCUMULATION OF NICOTINE DERIVATIVES IN THE CULTURE MEDIUM OF ARTHROBACTER NICOTINOVORANS pAO1

Previous studies have shown that the metabolic intermediate 6-hidroxy-D-nicotine (6HNic) found in the Arthrobacter nicotinovorans pAO1+ nicotine catabolic pathway has the ability to bind nicotinic acetylcholine receptors and to sustain spatial memory in rats. These properties make 6HNic a valuable compound with some potential for medical applications, thereby a suitable, simple and efficient method for producing 6-hidroxy-D-nicotine is necessary. Here, we focus on identifying the best moment for harvesting A. nicotinovorans cells in order to directly convert nicotine to 6HNic with the best yield. The growth of A. nicotinovorans pAO1+ was monitored and the correlation between the growth phases and nicotine metabolism was established. After about 5 hours of lag, the strain entered the log phase and was fully grown after 10 hours. The nicotine concentration began to drop dramatically as the pAO1+ culture reached saturation and was depleted in 5 hours. As the nicotine concentration dropped, 6HNic began to accumulate, reaching the maximum levels after about 11 hours of growth. Two other products could be detected by HPLC, one which was identified as the nicotine-blue (NB) pigment and a second a still unknown end-product

Anxiolytic, Promnesic, Anti-Acetylcholinesterase and Antioxidant Effects of Cotinine and 6-Hydroxy-L-Nicotine in Scopolamine-Induced Zebrafish (<i>Danio rerio</i>) Model of Alzheimer’s Disease

Cotinine (COT) and 6-hydroxy-L-nicotine (6HLN) are two nicotinic derivatives that possess cognitive-improving abilities and antioxidant properties in different rodent models of Alzheimer’s disease (AD), eluding the side-effects of nicotine (NIC), the parent molecule. In the current study, we evaluated the impact of COT and 6HLN on memory deterioration, anxiety, and oxidative stress in the scopolamine (SCOP)-induced zebrafish model of AD. For this, COT and 6HLN were acutely administered by immersion to zebrafish that were treated with SCOP before testing. The memory performances were assessed in Y-maze and object discrimination (NOR) tasks, while the anxiety-like behavior was evaluated in the novel tank diving test (NTT). The acetylcholinesterase (AChE) activity and oxidative stress were measured from brain samples. The RT-qPCR analysis was used to evaluate the npy, egr1, bdnf, and nrf2a gene expression. Our data indicated that both COT and 6HLN attenuated the SCOP-induced anxiety-like behavior and memory impairment and reduced the oxidative stress and AChE activity in the brain of zebrafish. Finally, RT-qPCR analysis indicated that COT and 6HLN increased the npy, egr1, bdnf, and nrf2a gene expression. Therefore, COT and 6HLN could be used as tools for improving AD conditions

Promnesic, Anxiolytic and Antioxidant Effects of <i>Glaucosciadium cordifolium</i> (Boiss.) Burtt & Davis Essential Oil in a Zebrafish Model of Cognitive Impairment

The purpose of this study was to investigate the effect of Glaucosciadium cordifolium essential oil (GCEO, 25 and 150 µL/L) on anxiety and learning and memory impairment induced by scopolamine (SCOP) in zebrafish. The chemical composition was analyzed by GC-MS, and the results showed that the highest content was limonene followed by α- and β-pinene, p-cymene and α-phellandrene. The dementia model was induced by SCOP (100 µM), whereas GCEO and galantamine (GAL, 1 mg/L) were delivered to the SCOP-induced model. It was found that GCEO significantly improved memory impairment and anxiety-like response induced by SCOP through the Y-maze, novel object recognition (NOR) test, and novel tank diving tests (NTT). Biochemical analyses showed that GCEO reduced SCOP-induced oxidative damage. Additionally, the cholinergic system activity was improved in the SCOP-induced model by decreasing the acetylcholinesterase (AChE) activity following the exposure to GCEO. It was clear that as a mixture, GCEO displays positive action in improving memory impairment through restoring cholinergic dysfunction and brain antioxidant status

<i>Angelica purpurascens</i> (Avé-Lall.) Gilli. Essential Oil Improved Brain Function via Cholinergic Modulation and Antioxidant Effects in the Scopolamine-Induced Zebrafish (<i>Danio rerio</i>) Model

Angelica purpurascens (Avé-Lall.) Gilli. is a medicinal plant that displays antioxidant, anticholinesterase, and neuroprotective properties. The effect of A. purpurascens essential oil (APO) on memory impairments and brain oxidative stress in zebrafish (Danio rerio) treated with scopolamine (Sco), as well as the underlying mechanism involved, were investigated in this study. Exposure to Sco (100 μM) resulted in anxiety in zebrafish, as assessed by the novel tank diving test (NTT), whereas spatial memory and novelty response dysfunctions, as evidenced by the Y-maze test and novel object recognition test (NOR), were noticed. When zebrafish were given Sco and simultaneously given APO (25 and 150 μL/L, once daily for 13 days), the deficits were averted. An increase in brain antioxidant enzymes, a reduction of lipid peroxidation, and protein oxidation were linked to this impact. Furthermore, acetylcholinesterase (AChE) activity was significantly reduced in the brains of APO-treated zebrafish. The main detected components in the APO composition were β-phellandrene (33.80%), sabinene (6.80%), α-pinene (5.30%), germacrene-D (4.50%), α-phellandrene (4.20%), and p-cymene (3.80%) based on gas chromatography–mass spectrometry (GC-MS) investigations. Our findings show that APO’s beneficial effect in a zebrafish model of Sco-induced memory impairment is mediated through multiple mechanisms, including the restoration of cholinergic system function and the improvement of the brain antioxidant state. As a result, APO could be employed as a potential source of bioactive molecules with useful biological properties and medicinal uses

(-)-cis-Carveol, a Natural Compound, Improves β-Amyloid-Peptide 1-42-Induced Memory Impairment and Oxidative Stress in the Rat Hippocampus

Alzheimer’s disease (AD) could be considered a multifactorial neurodegenerative disorder characterized by the accumulation of the β-amyloid-peptide (Aβ) within the brain leading to cognitive deficits, oxidative stress, and neuroinflammation. The present work was carried out to investigate the neuroprotective effect of (-)-cis-carveol (1% and 3%, for 21 days) against the β-amyloid-peptide 1-42- (Aβ1-42-) induced AD. Twenty-five rats were divided into five groups (n=5/group): the first group—control (sham-operated); the second group—Aβ1-42 (1 mM) that received donepezil treatment (5 mg/kg, as the positive reference drug in the Y-maze and the radial arm maze tests); the third group—Aβ1-42 (1 mM); the fourth and fifth groups—Aβ1-42 (1 mM) that received (-)-cis-carveol treatment groups (1% and 3%). The results of this study demonstrated that (-)-cis-carveol improved Aβ1-42-induced memory deficits examined by using Y-maze and radial arm maze in vivo tests. Also, the biochemical analyses of the hippocampus homogenates showed that (-)-cis-carveol reduced hippocampal oxidative stress caused by Aβ1-42. Our results suggested that the use of (-)-cis-carveol may be suitable for decreasing AD-related symptoms

Bay Leaf (<i>Laurus Nobilis</i> L.) Incense Improved Scopolamine-Induced Amnesic Rats by Restoring Cholinergic Dysfunction and Brain Antioxidant Status

Bay leaf (Laurus nobilis L.) has been shown to possesses various biological activities such as wound healing activity, antioxidant activity, antibacterial activity, antiviral activity, immunostimulant activity, anticholinergic activity, antifungal activity, insect repellant activity, anticonvulsant activity, antimutagenic activity, and analgesic and anti-inflammatory activity. The present study aimed to investigate whether the bay leaf incense (BL) elicits the memory formation via the action on the cholinergic system using a scopolamine (Sco)-induced rat model. Rats were exposed to BL over 5 min in a smoking chamber apparatus once daily for 22 days, whereas memory impairment was induced by Sco (0.7 mg/kg), a muscarinic receptor antagonist, delivered 30 min before each behavioral test. The phytochemical composition of BL was achieved by gas chromatograph–mass spectrometry (GCMS). Behavioral effects in rats were assessed by Y-maze, radial arm maze (RAM), and novel object recognition (NOR) paradigms. Additionally, the acetylcholinesterase (AChE) activity and the oxidative stress markers in the rat hippocampus were also evaluated. Exposure to BL significantly ameliorated Sco-induced cognitive impairment and oxidative stress in the rat hippocampus. The obtained results suggested that BL-induced ameliorative cognitive effects are mediated by enhancement of the cholinergic system and antioxidant activities

Bay Leaf (Laurus Nobilis L.) Incense Improved Scopolamine-Induced Amnesic Rats by Restoring Cholinergic Dysfunction and Brain Antioxidant Status

Bay leaf (Laurus nobilis L.) has been shown to possesses various biological activities such as wound healing activity, antioxidant activity, antibacterial activity, antiviral activity, immunostimulant activity, anticholinergic activity, antifungal activity, insect repellant activity, anticonvulsant activity, antimutagenic activity, and analgesic and anti-inflammatory activity. The present study aimed to investigate whether the bay leaf incense (BL) elicits the memory formation via the action on the cholinergic system using a scopolamine (Sco)-induced rat model. Rats were exposed to BL over 5 min in a smoking chamber apparatus once daily for 22 days, whereas memory impairment was induced by Sco (0.7 mg/kg), a muscarinic receptor antagonist, delivered 30 min before each behavioral test. The phytochemical composition of BL was achieved by gas chromatograph–mass spectrometry (GCMS). Behavioral effects in rats were assessed by Y-maze, radial arm maze (RAM), and novel object recognition (NOR) paradigms. Additionally, the acetylcholinesterase (AChE) activity and the oxidative stress markers in the rat hippocampus were also evaluated. Exposure to BL significantly ameliorated Sco-induced cognitive impairment and oxidative stress in the rat hippocampus. The obtained results suggested that BL-induced ameliorative cognitive effects are mediated by enhancement of the cholinergic system and antioxidant activities