Assessment of the medicinal potentials of the methanol extracts of the leaves and stems of Buddleja saligna

<p>Abstract</p> <p>Background</p> <p><it>Buddleja saligna </it>Willd (Loganiaceae) is a small to medium-sized evergreen tree; trunk short, often gnarled and crooked; crown dense, rounded or domed-shaped; foliage greyish green. The wild olives are traditionally used to lower blood pressures in many parts of the world. In southern Africa, bark and leaf decoctions are used to treat colic, coughs, colds, sore eyes, urinary problems and as purgatives.</p> <p>Methods</p> <p>The antibacterial, antioxidant activities and phenolic contents of the methanol extracts of the leaves and stems of <it>Buddleja saligna </it>were evaluated using <it>in vitro </it>standard methods. Spectrophotometry was the basis for the determinations of total phenol, total flavonoids, flavonols, and proanthocyanidins. Tannins, quercetin and catechin equivalents were used for these parameters. The antioxidant activities of the leaves and stem extracts of <it>Buddleja saligna </it>were determined by ABTS, DPPH, and ferrous reducing antioxidant property (FRAP) methods. Laboratory isolates of 10 bacteria species which included five Gram-positive and five Gram-negative strains were used to assay for antibacterial activity of this plant.</p> <p>Results</p> <p>The antioxidant activities of the leaves as determined by the ABTS and DPPH were similar to that of the stem. The flavonoids and the flavonols contents of the leaves were higher than that of the stem but the total phenols, proanthocyanidins and FRAP activities were higher in the methanol extracts of the stem. The extracts did show activity against both Gram-positive and Gram-negative bacteria. For instance, while the methanol extract of the leaves showed good activities on all the organisms except <it>Serratia marcescens </it>and <it>Pseudomonas aeruginosa </it>at MICs of between 2.5 and 5.0 mg/ml, the extract of the stem only showed activities on <it>Bacillus cereus, Streptococcus pyrogens </it>and <it>Pseudomonas aeruginosa </it>at the same concentration.</p> <p>Conclusion</p> <p>The results from this study indicate that the leaves and stem extracts of <it>Buddleja saligna </it>possess antioxidant properties and could serve as free radical inhibitors or scavenger or, acting possibly as primary antioxidants. Although, the antibacterial properties of <it>Buddleja saligna </it>are not as effective as the standard drugs-Chloramphenicol and Streptomycin, they still possess some activity against bacterial strains used in this study. <it>Buddleja saligna </it>may therefore be a good candidate for functional foods as well as pharmaceutical plant-based products.</p

Antimicrobial activity of neotropical wood and bark extracts

A total of 203 wood and bark extracts obtained from a Neotropical lowland rainforest in French Guiana were tested for antimicrobial activity against a panel of four human pathogens. Inhibitory activity against #Staphylococcus aureus was regularly observed. Significant growth inhibition against #Enterococcus faecilis was found in species belonging to the plant genus #Sloanea (Elaeocarpaceae) and various Sapotaceae. The plant genera #Eschweilera, #Gustavia and #Couratari (Lecythidaceae) showed notable growth inhibitory activity against both #Escherichia coli and #Enterococcus faecilis. Fractionation of the active extracts showed that the activities against Gram-positive and Gram-negative bacteria appear to be associated with different compounds. In some cases several replicates were sampled, showing that intraspecific activity levels may vary. The results of the screening experiments are compared to ethnomedicinal information available from northern South America and adjacent areas. (Résumé d'auteur

Antimicrobial activity of neotropical wood and bark extracts

A total of 203 wood and bark extracts obtained from a Neotropical lowland rainforest in French Guiana were tested for antimicrobial activity against a panel of four human pathogens. Inhibitory activity against #Staphylococcus aureus was regularly observed. Significant growth inhibition against #Enterococcus faecilis was found in species belonging to the plant genus #Sloanea (Elaeocarpaceae) and various Sapotaceae. The plant genera #Eschweilera, #Gustavia and #Couratari (Lecythidaceae) showed notable growth inhibitory activity against both #Escherichia coli and #Enterococcus faecilis. Fractionation of the active extracts showed that the activities against Gram-positive and Gram-negative bacteria appear to be associated with different compounds. In some cases several replicates were sampled, showing that intraspecific activity levels may vary. The results of the screening experiments are compared to ethnomedicinal information available from northern South America and adjacent areas. (Résumé d'auteur