Pinus halepensis Essential Oil Ameliorates Aß1-42-Induced Brain Injury by Diminishing Anxiety, Oxidative Stress, and Neuroinflammation in Rats.

The Pinus L. genus comprises around 250 species, being popular worldwide for their medicinal and aromatic properties. The present study aimed to evaluate the P. halepensis Mill. essential oil (PNO) in an Alzheimer's disease (AD) environment as an anxiolytic and antidepressant agent. The AD-like symptoms were induced in Wistar male rats by intracerebroventricular administration of amyloid beta1-42 (Aß1-42), and PNO (1% and 3%) was delivered to Aß1-42 pre-treated rats via inhalation route for 21 consecutive days, 30 min before behavioral assessments. The obtained results indicate PNO's potential to relieve anxious-depressive features and to restore redox imbalance in the rats exhibiting AD-like neuropsychiatric impairments. Moreover, PNO presented beneficial effects against neuroinflammation and neuroapoptosis in the Aß1-42 rat AD model.

Conifer Essential Oils Reversed Amyloid Beta1-42 Action by Modulating BDNF and ARC Expression in The Rat Hippocampus.

BACKGROUND: The conifer species Pinus halepensis (Pinaceae) and Tetraclinis articulata (Cupressaceae) are widely used in traditional medicine due to their beneficial health properties. OBJECTIVE: This study aimed to investigate the mechanisms by which P. halepensis and T. articulata essential oils (1% and 3%) could exhibit neuroprotective effects in an Alzheimer's disease (AD) rat model, induced by intracerebroventricular (i.c.v.) administration of amyloid beta1-42 (Aß1-42). METHODS: The essential oils were administered by inhalation to the AD rat model, once daily, for 21 days. DNA fragmentation was assessed through a Cell Death Detection ELISA kit. Brainderived neurotrophic factor (BDNF), activity-regulated cytoskeleton-associated protein (ARC), and interleukin-1ß (IL-1ß) gene expressions were determined by RT-qPCR analysis, while BDNF and ARC protein expressions were assessed using immunohistochemistry technique. RESULTS: Our data showed that both essential oils substantially attenuated memory impairments, with P. halepensis mainly stimulating ARC expression and T. articulata mostly enhancing BDNF expression. Also, the inhalation of essential oils reduced IL-1ß expression and induced positive effects against DNA fragmentation associated with Aß1-42-induced toxicity, further contributing to the cognitive improvement in the rats with the AD-like model Conclusion: Our findings provide further evidence that these essential oils and their chemical constituents could be natural agents of therapeutic interest against Aß1-42-induced neurotoxicity.

Anxiolytic and Antidepressant-Like Effects of Conyza canadensis Aqueous Extract in the Scopolamine Rat Model.

Conyza canadensis is a plant widely used in traditional medicine in Morocco for the treatment of varied health challenges. However, to the best of our knowledge, there is no scientific study justifying the traditional use of Conyza extract as an anxiolytic and antidepressant agent. Moreover, data regarding the polyphenolic fraction is limited. Therefore, the present study was conducted to investigate the chemical composition of an aqueous extract obtained from the aerial parts of Conyza, its antioxidant potential, and the anxiolytic and antidepressant-like effects of the sample (100 and 200 mg/kg body weight (bw)) in the scopolamine (Sco) (0.7 mg/kg bw) rat model. To achieve this purpose, a variety of antioxidant tests (including free radical-scavenging activity and lipoxygenase-inhibitory potential assays) and behavioral procedures, such as the elevated plus-maze and forced swimming tests, were performed. The results demonstrated that the aqueous extract of Conyza canadensis is rich in catechins and flavonoids which possess good antioxidant activity. Additionally, concentrations of 100 and 200 mg/kg of the extract exhibited significant anxiolytic and antidepressant-like profiles following scopolamine treatment. Therefore, we propose that the use of Conyza canadensis could be a new pharmacological target for the amelioration of major depression.

Memory-Enhancing Effects of Origanum majorana Essential Oil in an Alzheimer's Amyloid beta1-42 Rat Model: A Molecular and Behavioral Study.

Origanum L. (Lamiaceae) is an important genus of medicinal and aromatic plants used in traditional medicine since ancient times as culinary herbs and remedies. The aim of the present study was to evaluate the chemical composition, as well as the biochemical and cellular activities of freshly prepared Origanum majorana L. essential oil (OmEO) in an Alzheimer's disease (AD) amyloid beta1-42 (Aß1-42) rat model. OmEO (1% and 3%) was inhaled for 21 consecutive days, while Aß1-42 was administered intracerebroventricularly to induce AD-like symptoms. Our data demonstrate that OmEO increased antioxidant activity and enhanced brain-derived neurotrophic factor (BDNF) expression, which in concert contributed to the improvement of cognitive function of animals. Moreover, OmEO presented beneficial effects on memory performance in Y-maze and radial arm-maze tests in the Aß1-42 rat AD model.

Pinus halepensis essential oil attenuates the toxic Alzheimer's amyloid beta (1-42)-induced memory impairment and oxidative stress in the rat hippocampus.

The most prevalent neurodegenerative disease is Alzheimer's dementia. It is determined by the deposits of amyloid-beta peptide which leads to memory impairment, oxidative stress, and neurodegeneration. Aromatherapy by using essential oils could represent a natural treatment option for Alzheimer's dementia. Therefore, this study aimed to identify the neuroprotective and nootropic effects of Pinus halepensis essential oil (PNO, 1% and 3%, administered for three weeks) in a rat model of acute amyloid beta (1-42) (Aß1-42) toxicity. Rats were behaviorally tested (radial arm maze and Y-maze activities being used). Rats were divided into five groups (n = 5 / group): first group - vehicle, second group - Aß1-42, the third and fourth group - PNO treatment groups (1% and 3%), and fifth group - donepezil group (as positive control, 5 mg/kg injected in Aß1-42-treated rats). Antioxidant activity of the investigated essential oil was assessed using radical scavenging assays, such as 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 3-ethylbenzothiazoline-6-sulfonic acid (ABTS) tests. Also, biochemical estimations of the brain homogenates for acetylcholinesterase and oxidative stress biomarkers were carried out. The essential oil reversed the amyloid beta (1-42)-induced decreasing of the spontaneous alternation in the Y-maze test and the amyloid beta (1-42)-induced increasing of the working and reference memory errors in the radial arm maze test. The amyloid beta (1-42)-induced modification of the balance oxidant-antioxidant and acetylcholinesterase action in the hippocampus of the rat has been ameliorated using the essential oil. These findings suggested that Pinus halepensis essential oil has nootropic and neuroprotective activities and may be regarded as a therapeutic tool for attenuation of Aß toxicity and neuronal dysfunction.

Tetraclinis articulata essential oil mitigates cognitive deficits and brain oxidative stress in an Alzheimer's disease amyloidosis model.

BACKGROUND: Tetraclinis articulata is used in traditional medicine and has been reported to possess antibacterial, antifungal, cytotoxic, anti-inflammatory and antioxidant properties. PURPOSE: This study investigated the effects of T. articulata essential oil on memory and brain oxidative stress in amyloid-ß peptide 1-42 (Aß1-42)-induced an Alzheimer's disease amyloidosis model. Moreover, the underlying mechanism for memory enhancement and antioxidant activity was investigated, thus supporting its traditional use with scientific evidence for further studies. METHODS: T. articulata essential oil was administered by inhalation to male Wistar rats once daily for 15 min period at doses of 1% and 3% for 21 days after the intracerebroventricular administration of Aß1-42 right-unilaterally to induce memory deficits. The chemical composition of the essential oil was done by GC-MS and GC-FID. Spatial memory of rats was tested using Y-maze and radial arm maze tests. The possible underlying mechanism for memory improvement exhibited by T. articulata essential oil was investigated by in vivo brain antioxidant effect and acetylcholinesterase (AChE) inhibitory effect. In vitro, experimental evaluations were assessed through DPPH and ABTS tests. RESULTS: The GC-MS and GC-FID data showed that the essential oil has a high percent of monoterpene hydrocarbons. Also, we demonstrated the essential oil reversed the Aß1-42-induced decreasing of the spontaneous alternation in the Y-maze test and the Aß1-42-induced increasing of the working and reference memory errors in the radial arm maze test. Furthermore, the Aß1-42-decreased the acetylcholinesterase activity and the oxidant-antioxidant status in the rat hippocampus was retrieved by the treatment with the essential oil. CONCLUSION: The study demonstrates that the essential oil could be a potent pharmacological agent against dementia by modulating cholinergic activity and promoting antioxidant action in the rat hippocampus.

Ameliorative effects of Matricaria chamomilla L. hydroalcoholic extract on scopolamine-induced memory impairment in rats: A behavioral and molecular study.

BACKGROUND: Matricaria chamomilla L. is a medicinal herb traditionally used as the anti-inflammatory, antimicrobial, antiviral, anxiolytic and antidepressant agent. Nevertheless, supporting evidence demonstrated its memory enhancing activity and antioxidant properties. PURPOSE: To investigate the effects of the hydroalcoholic extract of M. chamomilla L. on memory processes in a scopolamine-induced a rat model of amnesia and to reveal its underlying mechanism of action. METHODS: The hydroalcoholic extract (25 and 75 mg/kg) was intraperitoneally administered to rats once daily for 7 days, and scopolamine (0.7 mg/kg) was injected 30 min before the behavioral testing to induce memory impairment. The phytochemical composition of the extract was quantified by HPLC/DAD analysis. Y-maze and radial arm-maze tests were employed for memory assessing. Acetylcholinesterase activity was measured in the rat hippocampus. Superoxide dismutase, glutathione peroxidase, and catalase specific activities along with the total content of reduced glutathione and protein carbonyl and malondialdehyde levels were also measured in the rat hippocampus. qRT-PCR was used to quantify BDNF mRNA and IL1ß mRNA expression in the rat hippocampus. RESULTS: We first identified the chlorogenic acid, apigenin-7-glucoside, rutin, cynaroside, luteolin, apigenin and derivatives of apigenin-7-glucoside as the extract major components. Furthermore, we showed that the extract reversed the scopolamine-induced decreasing of the spontaneous alternation in the Y-maze test and the scopolamine-induced increasing of the working and reference memory errors in the radial arm maze test. Also, the scopolamine-induced alteration of the acetylcholinesterase activity and the oxidant-antioxidant balance in the rat hippocampus was recovered by the treatment with the extract. Finally, we demonstrated that the extract restored the scopolamine-decreased BDNF expression and increased IL1ß expression in the rat hippocampus. CONCLUSION: These findings suggest that the extract could be a potent neuropharmacological agent against amnesia via modulating cholinergic activity, neuroinflammation and promoting antioxidant action in the rat hippocampus.

Lactuca capensis reverses memory deficits in Aß1-42-induced an animal model of Alzheimer's disease.

We investigated the neuropharmacological effects of the methanolic extract from Lactuca capensis Thunb. leaves (100 and 200 mg/kg) for 21 days on memory impairment in an Alzheimer's disease (AD) rat model produced by direct intraventricular delivery of amyloid-ß1-42 (Aß1-42). Behavioural assays such as Y-maze and radial arm maze test were used for assessing memory performance. Aß1-42 decreased cognitive performance in the behavioural tests which were ameliorated by pre-treatment with the methanolic extract. Acetylcholinesterase activity and oxidant-antioxidant balance in the rat hippocampus were abnormally altered by Aß1-42 treatment while these deficits were recovered by pre-treatment with the methanolic extract. In addition, rats were given Aß1-42 exhibited in the hippocampus decreased brain-derived neurotrophic factor (BDNF) mRNA copy number and increased IL-1ß mRNA copy number which was reversed by the methanolic extract administration. These findings suggest that the methanolic extract could be a potent neuropharmacological agent against dementia via modulating cholinergic activity, increasing of BDNF levels and promoting antioxidant action in the rat hippocampus.

Cognitive-enhancing and antioxidant activities of the aqueous extract from Markhamia tomentosa (Benth.) K. Schum. stem bark in a rat model of scopolamine.

BACKGROUND: Plants of the genus Markhamia have been traditionally used by different tribes in various parts of West African countries, including Cameroun. Markhamia tomentosa (Benth.) K. Schum. (Bignoniaceae) is used as an antimalarial, anti-inflammatory, analgesic, antioxidant and anti-Alzheimer agent. The current study was undertaken in order to investigate its anti-amnesic and antioxidant potential on scopolamine-induced cognitive impairment and to determine its possible mechanism of action. METHODS: Rats were pretreated with the aqueous extract (50 and 200 mg/kg, p.o.), for 10 days, and received a single injection of scopolamine (0.7 mg/kg, i.p.) before training in Y-maze and radial arm-maze tests. The biochemical parameters in the rat hippocampus were also assessed to explore oxidative status. Statistical analyses were performed using two-way ANOVA followed by Tukey's post hoc test. F values for which p < 0.05 were regarded as statistically significant. RESULTS: In the scopolamine-treated rats, the aqueous extract improved memory in behavioral tests and decreased the oxidative stress in the rat hippocampus. Also, the aqueous extract exhibited anti-acetylcholinesterase activity. CONCLUSIONS: These results suggest that the aqueous extract ameliorates scopolamine-induced spatial memory impairment by attenuation of the oxidative stress in the rat hippocampus.

Antidepressant Flavonoids and Their Relationship with Oxidative Stress.

Depression is a serious disorder that affects hundreds of millions of people around the world and causes poor quality of life, problem behaviors, and limitations in activities of daily living. Therefore, the search for new therapeutic options is of high interest and growth. Research on the relationship between depression and oxidative stress has shown important biochemical aspects in the development of this disease. Flavonoids are a class of natural products that exhibit several pharmacological properties, including antidepressant-like activity, and affects various physiological and biochemical functions in the body. Studies show the clinical potential of antioxidant flavonoids in treating depressive disorders and strongly suggest that these natural products are interesting prototype compounds in the study of new antidepressant drugs. So, this review will summarize the chemical and pharmacological perspectives related to the discovery of flavonoids with antidepressant activity. The mechanisms of action of these compounds are also discussed, including their actions on oxidative stress relating to depression.