Acute and sub-chronic oral toxicity assessment of the leaf aqueous extract of Kalanchoe crenata (Crassulaceae)

Previous studies demonstrated that the leaves of Kalanchoe crenata (Crassulaceae) possess analgesic, anti-inflammatory, anticonvulsant and cardiovascular activities but nothing is known about the toxicity of this plant material. The objective of the present study was to evaluate the acute and sub-chronic toxicities of the aqueous extract of the leaves of K. crenata (AEKC) prepared as a dry leaves decoction. Acute oral toxicity of the AEKC was evaluated in mice at doses 2, 4, 6, and 8 g/kg. Animals were observed for 3 hours post administration for signs and symptoms of intoxication. Survivors were followed up for 14 days after treatment. Wistar rats of both sexes were used for sub-chronic toxicity. They were orally treated with the AEKC at doses of 300, 600 and 1200 mg/kg/day for 4 consecutive weeks. They were further euthanized and blood was collected for biochemical and hematological analyses. A single acute administration of AEKC reduced the sensitivity to pain and the mobility of animals. These behavioral modifications disappeared 3 hours after administration. Only the dose of 8 g/kg caused the death of one female mouse out of 6, inferring a LD50 greater than 8 g/kg. The daily administration of AEKC did not induce mortality, behavioral modifications, significant variations of body weight, relative weights of the liver and kidney and plasma content of Alanine amino transferase (ALAT) and aspartate amino transferase (ASAT). Besides, no significant difference was observed on glomerular filtration rate and other parameters of renal excretion. Meanwhile, at the dose of 300 mg/kg/day, a significant increase in total bilirubin, free bilirubin and a significant decrease in conjugated bilirubin and plasma creatinine were registered. These results suggest that the aqueous extract of the leaves of K. crenata can be classified as a non-toxic substance. However, attention should be paid on the hepatic function.Keywords: Acute and sub-chronic toxicity, aqueous extract, Kalanchoe crenata, Crassulacea

Aqueous Root Bark Extract of Daniellia oliveri (Hutch. & Dalz.) (Fabaceae) Protects Neurons against Diazepam-Induced Amnesia in Mice

Daniellia oliveri (DO) is a traditional medicinal plant used for the treatment of diseases such as inflammation, schizophrenia, and epilepsy in Nigeria, Kenya, Congo, and Cameroon. This study was carried out to evaluate the potential neuroprotection effect of the aqueous root bark extract of Daniellia oliveri against diazepam-induced amnesia in mice. Thirty-six adult male mice were distributed into six groups: the three test groups received Daniellia oliveri root bark extract (100, 200, and 300 mg/kg), the normal control group received distilled water (10 ml/kg), a positive control group received piracetam (150 mg/kg), and the negative control received diazepam (2.5 mg/kg). Learning and memory were evaluated using the radial arm maze and the T-maze. Biomarkers of oxidative stress were also quantified in mice brains. Statistical analyses were performed using two-way ANOVA followed by Tukey’s post hoc test. Daniellia oliveri root bark aqueous extract decreased the number of working memory errors and number of reference memory errors in amnesic mice evaluated in the radial arm maze. Also, an increase in glutathione activity and a decrease in malondialdehyde levels were noted in the hippocampi homogenate of the extract-treated mice as compared to the diazepam-demented but untreated group. Moreover, pretreatment with Daniellia oliveri aqueous root bark extract reversed the decrease in hippocampal cell density observed in the nontreated diazepam group. Taken together, these results suggest that the aqueous extract of DO leaves possesses antioxidant potential and might provide an opportunity for the management of neurological abnormalities in amnesic conditions

Cashew (<i>Anacardium occidentale</i>) Extract: Possible Effects on Hypothalamic–Pituitary–Adrenal (HPA) Axis in Modulating Chronic Stress

Depression presents a significant global health burden, necessitating the search for effective and safe treatments. This investigation aims to assess the antidepressant effect of the hydroethanolic extract of Anacardium occidentale (AO) on depression-related behaviors in rats. The depression model involved 42 days of unpredictable chronic mild stress (UCMS) exposure and was assessed using the sucrose preference and the forced swimming (FST) test. Additionally, memory-related aspects were examined using the tests Y-maze and Morris water maze (MWM), following 21 days of treatment with varying doses of the AO extract (150, 300, and 450 mg/kg) and Imipramine (20 mg/kg), commencing on day 21. The monoamines (norepinephrine, serotonin, and dopamine), oxidative stress markers (MDA and SOD), and cytokines levels (IL-1β, IL-6, and TNF-α) within the brain were evaluated. Additionally, the concentration of blood corticosterone was measured. Treatment with AO significantly alleviated UCMS-induced and depressive-like behaviors in rats. This was evidenced by the ability of the extract to prevent further decreases in body mass, increase sucrose consumption, reduce immobility time in the test Forced Swimming, improve cognitive performance in both tests Y-maze and the Morris water maze by increasing the target quadrant dwelling time and spontaneous alternation percentage, and promote faster feeding behavior in the novelty-suppressed feeding test. It also decreased pro-inflammatory cytokines, corticosterone, and MDA levels, and increased monoamine levels and SOD activity. HPLC-MS analysis revealed the presence of triterpenoid compounds (ursolic acid, oleanolic acid, and lupane) and polyphenols (catechin quercetin and kaempferol). These results evidenced the antidepressant effects of the AO, which might involve corticosterone and monoaminergic regulation as antioxidant and anti-inflammatory activities

Neuroprotective Potential of <i>Guiera senegalensis</i> (Combretaceae) Leaf Hydroethanolic Extract against Cholinergic System Dysfunctions and Oxidative Stress in Scopolamine-Induced Cognitive Impairment in Zebrafish (<i>Danio rerio</i>)

Guiera senegalensis JF Gmel. (Combretaceae) (GS) is a plant used in traditional medicine in West Africa for the treatment of several diseases, such as epilepsy and depression. However, its potential benefits in improving scopolamine (Sco)-induced memory impairment and brain oxidative stress in zebrafish have been investigated. In the present study, zebrafish (Danio rerio) were treated with GS (1, 4, and 8 μg/L) for 19 days as well as Sco (100 µM) 30 min before behavioral tests. Behavioral performance was assessed by the Y-maze test and novel object recognition test (NOR), whereas anxiety response was evaluated in the novel tank diving test (NTT). Subsequently, high-performance liquid chromatography (HPLC) was used to evaluate the GS chemical composition. Sco promoted oxidative stress and acetylcholinesterase (AChE) activity. Moreover, both oxidative stress parameters and AChE activity were ameliorated by GS treatment. Accordingly, the present findings further provided the potential use of GS as a natural, alternative treatment against cognitive disorders associated to Alzheimer’s disease (AD)