Ameliorative effects of Albizia adianthifolia aqueous extract against pentylenetetrazole-induced epilepsy and associated memory loss in mice: Role of GABAergic, antioxidant defense and anti-inflammatory systems

Albizia adianthifolia (Schumach.) (Fabaceae) is a medicinal herb used for the treatment of epilepsy and memory impairment. This study aims to investigate the anticonvulsant effects of Albizia adianthifolia aqueous extract against pentylenetetrazole (PTZ)-induced spontaneous convulsions in mice; and determine whether the extract could mitigate memory impairment, oxidative/nitrergic stress, GABA depletion and neuroinflammation. Ultra-high performance liquid chromatography/mass spectrometry analysis was done to identify active compounds from the extract. Mice were injected with PTZ once every 48 h until kindling was developed. Animals received distilled water for the normal group and negative control groups, doses of extract (40, 80, or 160 mg/kg) for the test groups and sodium valproate (300 mg/kg) for the positive control group. Memory was measured using Y maze, novel object recognition (NOR) and open field paradigms, while the oxidative/nitrosative stresses (MDA, GSH, CAT, SOD and NO), GABAergic transmission (GABA, GABA-T and GAD) and neuro-inflammation (TNF-α, IFN-γ, IL- 1β, and IL-6) were determined. Brain photomicrograph was also studied. Apigenin, murrayanine and safranal were identified in the extract. The extract (80-160 mg/kg) significantly protected mice against seizures and mortality induced by PTZ. The extract significantly increased the spontaneous alternation and the discrimination index in the Y maze and NOR tests, respectively. PTZ kindling induced oxidative/nitrosative stress, GABA depletion, neuroinflammation and neuronal cells death was strongly reversed by the extract. The results suggest that the anticonvulsant activity of Albizia adianthifolia extract is accompanied by its anti-amnesic property, and may be supported by the amelioration of oxidative stress, GABAergic transmission and neuroinflammation.

Estrogenic and anti-amnesic potential of Millettia griffoniana Baill. (Fabaceae) ethanolic extract on scopolamine-induced memory impairment in ovariectomized Wistar rats

ETHNOPHARMACOLOGICAL RELEVANCE

Dementias including Alzheimer disease (AD) are three times higher in menopausal women than in men. Phytoestrogens, a group of plant-derived compounds are known to alleviate menopausal complaints including dementia. Millettia griffoniana Baill is a phytoestrogen-rich plant used to treat menopausal complaints and dementia.

AIM

Evaluating the estrogenic and neuroprotective potential of Millettia griffoniana on ovariectomized (OVX) rats.

MATERIALS AND METHODS

The in vitro safety of M. griffoniana ethanolic extract was assayed by MTT in human mammary epithelial (HMEC) and mouse neuronal (HT-22) cells and its lethal dose 50 (LD₅₀) was estimated following OECD 423 guidelines. For estrogenicity, in vitro the well known E-screen assay on MCF-7 cells was performed and in vivo four groups of OVX rats were treated either with 75, 150 and 300 mg/kg M. griffoniana extract doses or estradiol (1 mg/kg BW) for three days; and changes in uterine and vagina were analyzed. Then, for neuroprotective effect, Alzheimer-type dementia induction was achieved by scopolamine (1.5 mg/kg B.W., i.p.) injection four days/week and M. griffoniana extract as well as piracetam (standard) were administered daily for 2 weeks to evaluate the extract's neuroprotective potential. The endpoints were the assessment of learning and working memory, oxidative stress state (SOD, CAT, and MDA) in brain, acetylcholine esterase (AChE) activity and the histopathological changes in hippocampus.

RESULTS

No toxic effect was observed when incubating mammary (HMEC) and neuronal (HT-22) cells with M. griffoniana ethanol extract for 24 h and its LD₅₀ was found >2000 mg/kg. The extract also exhibited both in vitro and in vivo estrogenic activities, displayed by a significant (p < 0.01) increment in MCF-7 cells population in vitro and an increase in the epithelium height of the vagina and the wet weight of the uterus mainly with the 150 mg/kg BW extract dose compared to untreated OVX rats. The extract also reversed scopolamine-induced memory impairment in rat by improving learning, working and reference memory. This was associated with an increment in CAT and SOD expression, alongside a decrement in MDA content and AChE activity in hippocampus. Further, the extract reduced neuronal cell loss in hippocampal structures (CA1, CA3 and dentate gyrus). High Performance Liquid Chromatography coupled with Mass Spectrometry (HPLC-MS) spectra, revealed the presence of numerous phytoestrogens in M. griffoniana extract.

CONCLUSION

M. griffoniana ethanolic extract has estrogenic, anticholinesterase and antioxidant activities that could account for its anti-amnesic effects. These findings therefore sheds light on why this plant is commonly used in the therapy of menopausal complaints and dementia.

Anxiolytic and antidepressant effects of Ziziphus mucronata hydromethanolic extract in male rats exposed to unpredictable chronic mild stress: Possible mechanisms of actions

ETHNOPHARMACOLOGICAL RELEVANCE

Ziziphus mucronata (ZM) is used traditionally in the treatment of mood and depression. However, no existing scientific data is confirming this traditional claim.

AIM OF THE STUDY

The present study was planned to investigate the anxiolytic and antidepressant-like effects of this plant in a stressed-induced depression model in rats.

MATERIALS AND METHODS

Depressive-like behaviors were induced by exposing rats to different stress paradigms daily for 30 days. A sucrose preference test was performed to assess anhedonia in rats. Anxiety and depression-related behavior were assessed. The oxidative parameters (lipid peroxidation, SOD and catalase activities) were evaluated. Pindolol and Flumazenil were also used to assess the mechanism of action of ZM extract.

RESULTS

The results showed that chronic administration of ZM (150, 300, and 600 mg/kg, p.o., 30 days) and imipramine treatment (20 mg/kg, p.o, 30 days) remarkably (P < 0.05) reversed the UCMS-induced behavioral changes observed in stress vehicle treated rats by reducing sucrose preference, decreased the immobility period in the FST and latency in NSF. Besides, ZM (300 and 600 mg/kg, p.o., 30 days) raised the percentages of time spent and number of open arms entries as well as the number of transitions. Also, ZM (300 mg/kg, (P < 0.05) decreased lipid peroxidation and increased both SOD and catalase activities (300 and 600 mg/kg, (P < 0.05)). These aforementioned behavioral indices were also completely nullified by pindolol a β-adrenoceptors blocker and 5-HT 1A/1B receptor antagonist but not by flumazenil, a benzodiazepine receptors antagonist.

CONCLUSION

ZM improved symptoms of anxiety and depression in behavioral despair paradigm in chronically stressed rats. The observed effects could be due to its capacities to restore the antioxidant status, and probably the modulation of monoamines transmissions.

Cholinergic Enhancing and Antioxidant Effect of Vigna subterranea (L.) Verdc. (Fabaceae) Landrace Aqueous Extract on Scopolamine-Induced Amnesia in Male Swiss Mice

The present study was conducted to investigate protective effects of the aqueous extract of V. subterranea seeds landrace on amnesia induced by scopolamine in mice. V. subterranea aqueous extract (100, 200 and 400 mg/kg BW) was administered by gavage for nine consecutive days and memory impairment was induced by repeated intraperitoneal injection of scopolamine (1.5 mg/kg). The Y-maze (YM), Morris water maze (MWM), novel object recognition paradigm (NOR) and the T maze (TM) were used to assess learning, memory and retention. Superoxide dismutase (SOD), Catalase (CAT), Malondialdehyde (MDA) levels and Acetylcholine esterase activity was also evaluated in the mice hippocampi homogenates. V. subterranea aqueous extract (400 mg/kg) significantly increased the percentage of spontaneous alternation in the YM task and decreased escape latency in the MWM. Moreover, this dose brought about a significantly improvement in the time spent in the preferred TM arm and discrimination index in the NOR tasks despite repeated scopolamine injection. Additionally, low acetylcholine esterase levels, reduced lipid peroxidation (malondialdehyde) but increased antioxidant enzymes (catalase and superoxide dismutase) activity was observed in hippocampi homogenate of mice pre-treated with the extract. A protective action against hippocampal cell damage was also evident. This finding suggests that the aqueous extract of V. subterranea seed landrace may improve learning and memory.