Endophytic Fungi from Alstonia boonei De Wild and Greenwayodendron suaveolens (Engl. and Diels) Verdc. subsp. Suaveolens Possess Inhibitory Activity against Pneumonia Causing Bacteria.

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.

Toxicity and Activity of Ethanolic Leaf Extract of Paullinia pinnata Linn (Sapindaceae) in Shigella flexneri-Induced Diarrhea in Wistar Rats.

Herbal products from Paullinia pinnata Linn are widely used in African folk medicine to treat several infectious diseases. Although the extracts from this plant has been shown to possess antimicrobial potential, their activity in infectious diarrhea is less reported. Diarrhea was induced by oral administration of 1.2 × 109 CFU/mL of Shigella flexneri to the rats. The infected rats were treated for 5 days with the doses of 111.42, 222.84, and 445.68 mg/kg of P pinnata. The level of biochemical parameters was assessed and histology of organs examined by 14 days subacute toxicity. S flexneri stool load was considerably reduced after 4 days of treatment with the dose of 445.68 mg/kg, 5 days at the dose of 222.84 mg/kg for the extract, and 2 days with ciprofloxacin. The dose of 111.42 mg/kg appeared efficient after 5 days of treatment. The creatinine level increased at the dose of 445.68 mg/kg in both male and female rats and decrease at the dose of 222.84 mg/mL in female rats while an increase was noted in the male rats. Liver and kidney histology were modified at the dose of 445.68 mg/kg while no change was observed at the doses of 111.42 and 222.84 mg/kg. P pinnata leaf extract is efficient against infectious diarrhea at 111.42 mg/kg without side effect.

Effect of Drypetes gossweileri essential oil and irradiation treatments on inhibition and sensitivity of bacterial spores.

This work assesses the effect of Drypetes gossweileri essential oil on germination of Bacillus spores inoculated in orange juice and milk. We also report the capacity of the essential oil at 0.25, 0.5 and 1 µg/mL to induce sensitivity of spores to some irradiation treatments. The concentrations of essential oil were chosen after sensory analysis. The results show that the essential oil inhibited spores germination with minimal inhibitory concentrations inhibiting spore germination (MICg) of 10 µg/mL in the orange juice. In milk, the spores appeared to be less sensitive with MICg varying from 20 to 40 µg/mL. The sensory analysis revealed 2.5 µg/mL as the acceptable concentration of essential oil in orange juice. The essential oil at 1 µg/mL induced the sensitivity of spore of three Bacillus to alpha radiation of 101.4 Gy. Ultraviolet-C and microwave treatments in the presence of essential oil in general led to higher inactivation of spores up to 100% in some cases.

Secondary metabolites from Triclisia gilletii (De Wild) Staner (Menispermaceae) with antimycobacterial activity against Mycobacterium tuberculosis.

Triclisinone (2), a new ochnaflavone derivative, was isolated from the aerial parts of Triclisia gilletii, along with known drypemolundein B (1) and eight other known compounds. The chemical shifts of drypemolundein B (1) have been partially revised based on reinterpretation of NMR spectroscopic data. The eight other secondary metabolites are composed of: (+)-nonacosan-10-ol (3); stigmasterol (4), 3-O-ß-D-glucopyranosylsitosterol (5), 3-O-ß-D-glucopyranosylstigmasterol (6); oleanic acid (7); myricetin (8), quercetin (9) and 3-methoxyquercetin (10). Their structures were elucidated using IR, MS, NMR 1D and 2D, 1H and 13C and comparison with literature data. Furthermore, compounds 1, 2, 5, 6, 8, 9 and the crude extract were tested against Mycobacterium tuberculosis. Compounds 1, 2, 8 and 9 displayed moderate to very good activity against resistant strain (codified AC 45) of M. tuberculosis with minimum inhibitory concentrations MICs ranging from 3.90 to 62.5 µg/mL.

Applying the hydrodistillation process to Pentadiplandra brazzeana Baill. root: a chemical assessment.

A chemical study of the volatile components obtained by applying the hydrodistillation and reflux processes to Pentadiplandra brazzeana roots was performed by GC-FID and GC-MS. The hydrodistillation process showed a total yield of 0.97% with 0.11% of essential oil and 0.86% of volatile compounds from the aqueous reaction medium; in the reflux process, the volatile extract yield was 1.03%. Benzylic-type isothiocyanates were the major degradation products of glucosinolates in the essential oil (95.0%); the CH2Cl2 extracts obtained from the aqueous solutions were characterised by alcohols and amines in both processes. This study has shown that during hydrodistillation, only 10% of the glucosinolate degradation products are recovered in the essential oil whereas 90% remain in the aqueous medium, being converted into alcohols and amines. The relative percentages of the different chemical classes recovered in our experimental conditions are discussed in relation with the glucosinolate composition in the raw material.

Antidiarrheal Activity of Dissotis multiflora (Sm) Triana (Melastomataceae) Leaf Extract in Wistar Rats and Subacute Toxicity Evaluation.

The present work was undertaken to evaluate antidiarrheal activity of ethanolic leaf extract of Dissotis multiflora (Sm) Triana (D. multiflora) on Shigella flexneri-induced diarrhea in Wistar rats and its subacute toxicity. Diarrhea was induced by oral administration of 1.2 × 109 cells/mL S. flexneri to rats. Antidiarrheal activity was investigated in rats with the doses of 111.42 mg/kg, 222.84 mg/kg, and 445.68 mg/kg. The level of biochemical parameters was assessed and organs histology examined by 14 days' subacute toxicity. S. flexneri stool load decreased significantly in dose-dependent manner. The level of ALT increased (p < 0.05) in male rats treated with the dose of 445.68 mg/kg while creatinine level increased in rats treated with both doses. In female rats, a significant decrease (p < 0.05) of the level of AST and creatinine was noted in rats treated with the dose of 222.84 mg/kg of D. multiflora. Histological exams of kidney and liver of treated rats showed architectural modifications at the dose of 445.68 mg/kg. This finding suggests that D. multiflora leaf extract is efficient against diarrhea caused by S. flexneri but the treatment with doses lower than 222.84 mg/kg is recommended while further study is required to define the exact efficient nontoxic dose.