Alzheimer’s disease is first characterised by memory loss related to the central cholinergic system alteration. Available drugs provide symptomatic treatment with known side effects. The present study is aimed to evaluate the properties of Carissa edulis aqueous extract on a Scopolamine mouse model as an attempt to search for new compounds against Alzheimer’s disease-related memory impairment. Memory impairment was induced by administration of 1 mg/kg (i.p.) of Scopolamine for 7 days, and mice were treated with Carissa edulis aqueous extract. Behavioural studies were performed using T-maze and novel object recognition task for assessing learning and memory and open field test for locomotion. Brain acetylcholinesterase enzyme (AChE) activity was measured to evaluate the central cholinergic system. The level of MDA, glutathione, and catalase activity were measured to evaluate the oxidative stress level. Administration of Scopolamine shows a decrease in learning and memory enhancement during behavioural studies. A significant decrease in the time spent in the preferred arm of T-maze, in the time spent in the exploration of the novel object, and in the discrimination index of the familiar object was also observed. The significant impairment of the central cholinergic system was characterised in mice by an increase of AChE activity to 2.55±0.10 mol/min/g with an increase in oxidative stress. Treatment with the different doses of Carissa edulis (62.8, 157, 314, and 628 mg/kg orally administrated) significantly increased the memory of mice in T-maze and novel object recognition tests and also ameliorated locomotion of mice in the open field. Carissa edulis aqueous extract treatment also decreases the AChE activity and brain oxidative stress. It is concluded that administration of Carissa edulis aqueous extract enhances memory of mice by reducing AChE activity and demonstrating antioxidant properties. This could be developed into a novel therapy against memory impairment related to Alzheimer’s disease.

Objective: This study aims to evaluate the in vitro antioxidant, anti-inflammatory activities of the aqueous and hydroethanolic extracts recipe of Alchornea cordifolia and Antrocaryon klaineanum. A preliminary phytochemical screening was carried out. Methods: The total phenols content was determined by the Folin Ciocalteu reagent method, while the antioxidant activity of both extracts was characterized by the 2-2diphenyl-1-picrilhidrazil (DPPH) and β-carotene assays. The anti-inflammatory activity of the extracts was evaluated as the inhibition of Bovine Serum Albumin (BSA) denaturation and antiproteinase activity. Results: The aqueous extracts of Alchornea cordifolia and Antrocaryon klaineanum contained more polyphenols [270 mg Ascorbic acid equivalent (AAE)/g dry weight (dw)] than the hydroethanolic recipe extract (262.41 mg AAE/g dw) at the same concentration level. On the other hand, the aqueous and hydroethanolic recipe extract had the same radical scavenging activity with the antiradical power of 0.851 and 0.830, respectively. Similarly, the recipe extract had the same reducing activity with reducing the power of 94.2±2.03 mg EAA/g dw and 97.4±4.16 mg EAA/g dw for the aqueous and hydroethanolic recipe extract of Alchornea cordifolia and Antrocaryon klaineanum respectively. For the anti-inflammatory activity it was observed that both extracts possess the same activity as Diclofenac® with an IC50 of 50.21 μg/ml. The phytochemical screening of the extracts revealed the presence of alkaloids, flavonoids, carbohydrates, phenols and tannins, which may account for their activities. Conclusion: The plant recipe extract studied possess antioxidant and anti-inflammatory potentials, which may be beneficiary to its consumers.

Two new compounds, an isoquinoline (1) and caloneuramide (2), a ceramide were isolated from the stem bark of Discoglypremna caloneura together with seven known compounds namely aurantiamide acetate (3), acetylaleuritolic acid (4), 3α-hydroxylaleuritolic acid 2 α-phydroxybenzoate (5), mixture of stigmasterol (6) and β-sitosterol (7), mixture of 7-oxo-stigmasterol (8) and 7-oxo-β-sitosterol (9). Their structures were determined based on data from literature and spectroscopic methods. Derivatization reactions on the isoquinoline led to two new compounds, the methylated (10) and acetylated (11) derivatives. Some compounds and extracts were evaluated for their cytotoxic and antiproteinase activity. Antiproteinase effect of compounds 1, 10 and 11 exhibited IC50 values of 10.77, 1.19 and 3.61 µg/mL respectively; significantly low compared to the standard drug, acetyl salicylic acid (IC50 = 20.28 µg/mL). Ethyl acetate and methanol extract exhibited moderate cytotoxicity activity on Chang liver cells with CC50 values of 167.90±2.20 and 106.30 ±2.03 µg/mL compared to the reference drug cucurmin (CC50 = 11.05 ± 1.04 µg/mL).

This study evaluated the antibacterial efficacy of methanolic extracts of isolated endophytic fungi from stem barks and leaves of Alstonia boonei De Wild and Greenwayodendron suaveolens (Engl. and Diels) Verdc. subsp. Suaveolens against Klebsiella pneumoniae ATCC 43816, Haemophilus influenzae ATCC 49247, Pseudomonas aeruginosa ATCC 27853, and Escherichia coli ATCC 35218, responsible for causing pneumonia. The endophytic fungi were isolated and characterized in the Potato Dextrose Agar (PDA), Sabouraud Dextrose Agar (SDA), and Czapek Dox Agar (CDA) media. The fungi and their methanolic extracts were tested for in vitro antibacterial potential by antagonistic assay for endophytic fungi against bacterial pathogens and microdilution method. The phytochemical screening of extracts was carried out according to the colorimetric and precipitation methods to reveal the presence of secondary metabolites. The results showed that 24 macroscopically and microscopically distinct endophytic fungi were isolated, identified, and stored. These endophytic fungi possessed antibacterial activity against the selected bacterial strains with inhibition zones ranging from 7.00 to 25.00 mm. The endophytic fungi GS15 and AB24 have presented the inhibitions zones of 20.33 mm and 25.00 mm, respectively, and these were better than the ones obtained for Levofloxacin®. The endophytes with inhibition zones greater than 10 mm were used for extraction of their secondary metabolites. The endophytic fungi extracts showed antibacterial activity with the minimum inhibitory concentrations (MICs) ranging from 6.25 × 10−4 to 2 × 10−2 g/L and the minimum bactericidal concentrations (MBCs) ranging from 2.5 × 10−3 to 2 × 10−2 g/L. The endophytic fungi GS15 extract was the most effective extract; it showed bactericidal effects on the tested bacterial strains. The phytochemical screening of the extracts revealed the presence of secondary metabolites classes, responsible for causing the obtained antibacterial activity. Thus, the endophytic fungi methanolic extracts from A. boonei and G. suaveolens have the potential to inhibit the growth of bacteria responsible for nosocomial pneumonia.

The present work aimed to determine the phytochemical components and evaluate the in vitro anti-inflammatory and anti-mycobacterial effects of hydroethanolic extracts of Allium sativum L bulbs, Drypetes gossweileri S. MOORE stem-barks and Pentadiplandra brazzeana Baill roots against several resistant strains of Mycobacterium tuberculosis. The phytochemical screenings of extracts were carried out according the colorimetric and precipitation tests to reveal the presence of phytochemical compounds. The anti-inflammatory effects of extracts were evaluated using in vitro Bovine Serum Albumin denaturation and proteinase inhibitory action assays. The inhibitory parameters of hydro-ethanol extracts were evaluated by the microdilution method agaisnt Mycobacterium tuberculosis. The phytochemical screening of hydro-ethanol extracts revealed the presence of phenols, polyphenols, flavonoids, alkaloids, cathechic tannins, triterpens, steroids, anthocyanins and leucoanthocyanins. The anti-inflammatory activity of hydro-ethanol extracts of D. gossweileri, P. brazzeana and A. sativum have shown the inhibitory concentrations 50 (IC50) values ranging from 356.70, 183.30 and 226.30 mg/mL for BSA denaturation and 31.92, 33.62 and 56.93 mg/mL for proteinase inhibitory action respectively. The hydroethanolic extracts of D. gossweileri, P. brazzeana and A. sativum exhibited moderate and weak anti-mycobacterial activities with the minimum inhibitory concentrations (MICs) ranging from 312.5 to 2500 μg/mL. A. sativum hydro-ethanol extract has shown the highest anti-mycobacterial activity with MIC of 312.5 μg/mL against isoniazid resistant of M. tuberculosis and extremely resistant drug strain of M. tuberculosis. These results suggest that hydro-ethanol extracts of A. sativum, D. gossweileri and P. brazzeana are efficient against tuberculosis caused by multi-resistant Mycobacterium tuberculosis strains and are able to resorb the inflammation induced during infection. Keywords: Anti-inflammatory activity, Anti-mycobacterial effect, Hydroethanolic extracts, Medicinal plants, Phytochemical screening.