Aqueous extract of Parkia biglobosa (Jacq.) R. Br. (Fabaceae) exerts antiepileptogenic, anti-amnesic, and anxiolytic-like effects in mice via mechanisms involving antioxidant and anti-inflammatory pathways

Abstract

Parkia biglobosa (Jacq.) R. Br. (Fabaceae) is a widely distributed tree, used in traditional medicine to treat amebiasis, hookworm infection, ascariasis, asthma, sterility, dental pain, headaches, cardiac disorders, and epilepsy. To date, no study on the effect of an aqueous extract of P. biglobosa on epileptogenesis and associated neuropsychiatric disorders has been undertaken. Therefore, this study aimed to investigate antiepileptogenic-, antiamnesic-, and anxiolytic-like effects of an aqueous extract of P. biglobosa using pentylenetetrazole (PTZ)-induced kindling in mice. Animals were divided into six groups of eight mice each. Thus, a PTZ group received distilled water (10 ml/kg, per os), a positive control group received sodium valproate (300 mg/kg, p.o.), and three test groups received the aqueous extract of P. biglobosa (80, 160, and 320 mg/kg, p.o.).In addition, a control group of eight mice receiving distilled water (10 ml/kg, p.o.) was formed. The treatments were administered to mice, 60 min before administration of PTZ (20 mg/kg, i.p.). These co-administrations were performed once daily, for 22 days. The number and duration of seizures (stages 1, 2, 3, and 4 of seizures) exhibited by each mouse were assessed for 30 min during the treatment period. Twenty-four hours following the last administration of the treatments and PTZ, novel object recognition and T-maze tests were performed to assess working memory impairment in mice, while the open field test was performed to assess anxiety-like behavior. After these tests, the animals were sacrificed, and the hippocampi were collected for biochemical and histological analysis. During the period of PTZ-kindling, the extract at all doses completely (p < 0.001) protected all mice against stages 3 and 4 of seizures when compared to sodium valproate, a standard antiepileptic drug. The extract also significantly (p < 0.001) attenuated working memory impairment and anxiety-like behavior. In post-mortem brain analyses, the extract significantly (p < 0.001) increased γ-aminobutyric acid (GABA) level and reduced oxidative stress and inflammation. Histological analysis showed that the aqueous extract attenuated neuronal degeneration/necrosis in the hippocampus. These results suggest that the extract is endowed with antiepileptogenic-, anti-amnesic-, and anxiolytic-like effects. These effects seem to be mediated in part by GABAergic, antioxidant, and anti-inflammatory mechanisms. These results suggest the merit of further studies to isolate the bioactive molecules responsible for these potentially therapeutically relevant effects of the extract.

Contemporary Insights into the Biological Mechanisms of Parkia biglobosa

“…In rat brain mitochondrial preparations, it was found to modulate Na + / K + -ATPase activity and improve ROS formation [2]. More recently, an aqueous extract of PB stem bark was found to protect mice from pentylenetetrazole-induced epileptic seizures, amnesia, and anxiety-like behavior while also reducing oxidative stress, inflammation, and degenerated or necrotic neurons in the hippocampus [4]. In vitro, Parkia biglobosa bark extract conferred protection against the cytotoxic, neurotoxic, and hemotoxic effects of venoms from two lethal snakes, Naja nigricollis and Echis ocellatus, and was able to delay mortality from the venoms in mice under in vivo conditions [74].…”

“…The neuroprotective properties of Parkia biglobosa are thought to be attributed, at least partially, to its GABAergic, antioxidant, and anti-inflammatory signaling mechanisms [4]. Several studies confirmed the antioxidant and anti-inflammatory potentials of the Parkia biglobosa plant in both in vitro and in vivo settings, and some of the therapeutic efficacy of the plant proceeded via these mechanisms [4,75].…”

“…Parkia biglobosa (PB) has more recently aroused the interest of researchers with its promising preclinical findings, suggesting it could be a valuable source of therapeutic compounds. Extracts of the leaf and/or stem bark were reported to exert antioxidant, hypotensive, cardioprotective, antihyperlipidemic, antidiabetic, antiepileptogenic, anti-amnesic, and anxiolytic-like effects in animal models [2][3][4][5][6][7], as well as antidiarrheal and antibacterial properties [8,9]. Furthermore, protein isolates from the seed exhibited hypolipidemic and cardioprotective effects [10,11], while the seeds were found to have vasorelaxant actions on smooth muscles, thereby initiating hypotensive effects [12].…”

Bioactive agents from Parkia biglobosa (Jacq.) R.Br. ex G. Don bark extracts for health promotion and nutraceutical uses

“…For exampel, it has been found to possess analgesic, anti-inflammatory, antimicrobial, antiepileptogenic, anti-amnesic and anxiolytic-like activities. [14][15][16] Additionally, phenolic compounds were found to be the major antimalarial components of P. biglobosa and have shown antimalarial activity against Plasmodium berghei and clinical isolate of Plasmodium falciparum. 17 Furthemore, extracts of fermented seeds of P. biglobosa were reported to exert a hypoglycaemic effect, thus demonstrating an antidiabetic effect.…”

“…Along with their renowned status in traditional medicine, their actual pharmacological effects validated by a panoply of studies have also been widely elaborated. For exampel, it has been found to possess analgesic, anti‐inflammatory, antimicrobial, antiepileptogenic, anti‐amnesic and anxiolytic‐like activities 14‐16 . Additionally, phenolic compounds were found to be the major antimalarial components of P. biglobosa and have shown antimalarial activity against Plasmodium berghei and clinical isolate of Plasmodium falciparum 17 .…”