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

Investigating the Potential of Essential Oils from Citrus reticulata Leaves in Mitigating Memory Decline and Oxidative Stress in the Scopolamine-Treated Zebrafish Model

Petitgrain essential oil (PGEO) is derived from the water distillation process on mandarin (Citrus reticulata) leaves. The chemical constituents of PGEO were analyzed by gas chromatography/mass spectrometry (GC/MS) method which revealed the presence of six compounds (100%). The major peaks were for methyl-N-methyl anthranilate (89.93%) and γ-terpinene (6.25%). Over 19 days, zebrafish (Tubingen strain) received PGEO (25, 150, and 300 μL/L) before induction of cognitive impairment with scopolamine immersion (SCOP, 100 μM). Anxiety-like behavior and memory of the zebrafish were assessed by a novel tank diving test (NTT), Y-maze test, and novel object recognition test (NOR). Additionally, the activity of acetylcholinesterase (AChE) and the extent of the brain's oxidative stress were explored. In conjunction, in silico forecasts were used to determine the pharmacokinetic properties of the principal compounds discovered in PGEO, employing platforms such as SwissADME, Molininspiration, and pKCSM. The findings provided evidence that PGEO possesses the capability to enhance memory by AChE inhibition, alleviate SCOP-induced anxiety during behavioral tasks, and diminish brain oxidative stress.

Effect of Laurus nobilis on bacteria and human transforming growth factor-β1

OBJECTIVE

In this study, we aimed to determine the phenolic compounds, the antibacterial activity of extract from Laurus nobilis leaves, and its possible effect on transforming growth factor-β1 expression level in peripheral blood mononuclear cells.

METHODS

The phenolic components of Laurus nobilis were identified by the high-performance liquid chromatography method. The antibacterial activity of this extract was determined by disk diffusion and broth microdilution methods. The transforming growth factor-β1 expression was analyzed using the RT-qPCR method.

RESULTS

Epicatechin was found in the highest amount and o-coumaric acid in the lowest amount. The half-maximal inhibitory concentration (IC50) was determined to be 55.17 μg/mL. The zones of inhibition and minimum inhibitory concentration for Staphylococcus aureus, Enterococcus faecalis, and Klebsiella pneumoniae were 15, 14, and 8 mm and 125, 250, and 1000 μg/mL, respectively. The change in transforming growth factor-β1 expression levels was found to be statistically significant compared with the control groups (p<0.0001).

CONCLUSION

Laurus nobilis extract was found to be effective against bacteria and altered the expression level of transforming growth factor-β1 in peripheral blood mononuclear cells.

Minocycline alleviated scopolamine-induced amnesia by regulating antioxidant and cholinergic function

Background and aim

Minocycline, a tetracycline derivative, has been found to exert neuroprotective properties. The current project aimed to assess the antioxidant status and cholinergic function in the amnesia induced by scopolamine.

Methods

We evaluated the passive avoidance performance, acetylcholine esterase (AChE) enzyme activity, and the oxidative stress indicators in the following groups: Normal control, scopolamine, and the treatment groups (the animals were given minocycline (10-30 mg/kg)).

Results

Scopolamine (intraperitoneal) injection was associated with impairment of passive avoidance performance and neurotoxicity. Minocycline pronouncedly ameliorated scopolamine injury as presented by the increased latency time to darkness and stay time in lightness along with the decreased darkness entry. Moreover, minocycline decreased lipid peroxidation, while it elevated the levels of superoxide dismutase, AChE enzymes, and thiol groups in both the cortex and hippocampus.

Conclusion

Our data suggested that minocycline modulated the antioxidant status and AChE in the brains, which may contribute to its protective effects against scopolamine-induced amnesia.

The Potential Neuroprotective Effect of Cyperus esculentus L. Extract in Scopolamine-Induced Cognitive Impairment in Rats: Extensive Biological and Metabolomics Approaches

The aim of the present study is to investigate the phytochemical composition of tiger nut (TN) (Cyperus esculentus L.) and its neuroprotective potential in scopolamine (Scop)-induced cognitive impairment in rats. The UHPLC-ESI-QTOF-MS analysis enabled the putative annotation of 88 metabolites, such as saccharides, amino acids, organic acids, fatty acids, phenolic compounds and flavonoids. Treatment with TN extract restored Scop-induced learning and memory impairments. In parallel, TN extract succeeded in lowering amyloid beta, β-secretase protein expression and acetylcholine esterase (AChE) activity in the hippocampus of rats. TN extract decreased malondialdehyde levels, restored antioxidant levels and reduced proinflammatory cytokines as well as the Bax/Bcl2 ratio. Histopathological analysis demonstrated marked neuroprotection in TN-treated groups. In conclusion, the present study reveals that TN extract attenuates Scop-induced memory impairments by diminishing amyloid beta aggregates, as well as its anti-inflammatory, antioxidant, anti-apoptotic and anti-AChE activities.

Altı Tıbbi Bitkinin Sitotoksik Etkileri ve SARS-CoV-2'ye Karşı Antiviral Etkinliğinin Araştırılması

Aim: Today, the COVID-19 pandemic, which causes deaths in 224 countries around the world, continues to show its effect all over the world. However, unfortunately, there are few studies that determine the effect of natural products derived from plants on COVID-19. However, as it is known, the source of most drugs is plants and medicinal aromatic plants have been used frequently for therapeutic purposes since the existence of humanity. The aim of this study is to investigate the cytotoxic effects of six medicinal plants such as Licorice (Glycyrrhiza glabra), Saffron (Crocus sativus L.), Black Cumin (Nigella sativa L.), Laurel (Lauris nobilis), Buckwheat (Lavandula stoechas) and Zahter (Thymbra spicata L. var. spicata) and their antiviral activities against SARS-CoV-2 in vitro conditions. Material and Method: This study was carried out in two stages. In the first stage, plants were collected and extracts were obtained. At the beginning of the second stage, cytotoxic effects on vero cells at non-cytotoxic broad-spectrum concentrations against SARS-CoV-2 in cell culture of six medicinal plants were investigated. In this step, the concentration of six ethnobotanically important medicinal plants that were not cytotoxic to SARS-CoV-2 was determined. In the continuation of the second stage, the plants were evaluated for the determination of viral replication inhibition and their antiviral effectiveness against SARS-CoV-2. In this step, in vitro antiviral effects of plants against SARS-CoV-2 were determined at a concentration that did not show cytotoxic effects.. Results: The concentration of six plants used in the study without cytotoxic effects was determined.. Among the plants examined, it was determined that the only plant that was effective against SARS-CoV-2 in vitro conditions was the licorice plant (Glycyrrhiza glabra). The licorice plant was found to inhibit SARS-CoV-2 in vitro at the 2nd dilution (1:4) after the initial concentration. Conclusion: According to the findings obtained from our study, it was determined that the licorice plant was effective against the SARS-CoV-2 in vitro conditions. Supported by further studies, it can be thought that our findings may contribute to the fight against the COVID-19 pandemic. Keywords: SARS-CoV-2, Antiviral Efficacy, Plant Extract, Licorice (Glycyrrhiza glabra), Saffron (Crocus sativus L.), Black Cumin (Nigella sativa L.), Laurel (Lauris nobilis), Buckwheat (Lavandula stoechas), Zahter (Thymbra spicata L. var. spicata).

Effect of Sanguisorba minor on scopolamine-induced memory loss in rat: involvement of oxidative stress and acetylcholinesterase

Sanguisorba minor (S. minor) has neuroprotective and antioxidant activities. However, its potential benefits in ameliorating learning and memory functions have been explored in no studies up to now. So, in the current study, rats were treated with S. minor hydro-ethanolic extract (50, 100, and 200 mg/kg, intraperitoneal (i.p.)) as well as rivastigmine (0.5 mg/kg, i.p.) for 21 consecutive days. Thereafter, their behavioral performance was assessed using Morris water maze (MWM) and passive avoidance (PA) tasks. Notably, 30 min before conducting the tasks, scopolamine was injected. Finally, the biochemical assessments were done using the brain tissue. The extract characterization was performed by liquid chromatography-mass spectrometry, which confirmed the presence of quercetin, myricetin, kaempferol, catechin, ellagic acid, and gallic acid derivatives. In the MWM test, the extract reduced both escape latency and the travelled distance, compared to the scopolamine group. Moreover, in the PA test, the latency to enter the dark chamber significantly increased by the extract, compared to the scopolamine group (p < 0.05-p < 0.001). Notably, the beneficial effects of S. minor on cognitive performance of the scopolamine-treated rats appeared to be similar or even better than rivastigmine in behavior performance. Similar to rivastigmine, it was observed that the extract attenuated both AChE activity and oxidative injury in the brain as evidenced by the increased antioxidant enzymes and total thiol content; however, it decreased malondialdehyde level (p < 0.05-p < 0.001). In conclusion, the results suggested the effectiveness of S. minor in preventing cognitive dysfunction induced by scopolamine. Accordingly, these protective effects might be produced by the regulation of cholinergic activity and oxidative stress. S. minor could be considered as a potential alternative therapy in cognition disorders.

Origanum vulgare ssp. hirtum (Lamiaceae) Essential Oil Prevents Behavioral and Oxidative Stress Changes in the Scopolamine Zebrafish Model

Origanum vulgare ssp. hirtum has been used as medicinal herbs promoting antioxidant, anti-inflammatory, antimicrobial, and neuroprotective activities. We investigated the protective effects and the mechanism of O. vulgare ssp. hirtum essential oil (OEO) on cognitive impairment and brain oxidative stress in a scopolamine (Sco)-induced zebrafish (Danio rerio) model of cognitive impairment. Our results show that exposure to Sco (100 µM) leads to anxiety, spatial memory, and response to novelty dysfunctions, whereas the administration of OEO (25, 150, and 300 µL/L, once daily for 13 days) reduced anxiety-like behavior and improved cognitive ability, which was confirmed by behavioral tests, such as the novel tank-diving test (NTT), Y-maze test, and novel object recognition test (NOR) in zebrafish. Additionally, Sco-induced brain oxidative stress and increasing of acetylcholinesterase (AChE) activity were attenuated by the administration of OEO. The gas chromatography-mass spectrometry (GC-MS) analyses were used to elucidate the OEO composition, comprising thymol (38.82%), p-cymene (20.28%), and γ-terpinene (19.58%) as the main identified components. These findings suggest the ability of OEO to revert the Sco-induced cognitive deficits by restoring the cholinergic system activity and brain antioxidant status. Thus, OEO could be used as perspective sources of bioactive compounds, displaying valuable biological activities, with potential pharmaceutical applications.