Antibacterial activity of <i>Tabernaemontana stapfiana</i> Britten (apocynaceae) extracts

Abstract

Antibacterial and phytochemical screening of methanolic, sequential extracts (hexane, dichloromethane, ethyl acetate and methanol) and alkaloid rich fractions of Tabernaemontana stapfiana Britten was carried out. The phytochemical screening showed the presence of alkaloids, flavonoids, coumarins, tannins and saponins that have been associated with antimicrobial activity. The stem and root bark methanolic extracts showed good activity against the bacterial strains used including the multiple drug resistant Staphylococcus aureus strain with minimum inhibitory concentrations ranging from 15.6 to 500 µg/ml and minimum bactericidal concentrations ranging from 31.25 to 500 µg/ml. The sequential extracts of the root and stem bark had high antimicrobial activity with minimum inhibitory concentrations (MICs) ranging between 3.9 and 250 µg/ml and minimum bactericidal concentrations (MBCs) ranging between 7.8 and 500 µg/ml against the tested microorganisms. The dichloromethane extract of the alkaloid rich fractions however exhibited reduced antibacterial activities as compared to methanol and sequential extracts but the dichloromethane:methanol (4:1) mixture showed high activity with MICs ranging between 15.6 and 250 µg/ml. These antibacterial efficacy studies suggest that Tabernaemontana stapfiana Britten could be a source of antibacterial agents.

Ethnobotanical Identification and Anti-microbial Evaluation of Some Anti-Diarrhoeal Plants Used by the Samburu Community, Kenya

“…These extracts together with others had some substantial amounts of tannins, saponins, flavonoids, terpenoids, alkaloids and cardiac glycosides that have been known to have antimicrobial properties. Thus their activity could be ascribed to the presence of the above phytochemicals and also to the cell wall properties of the tested isolates (Ruttoh et al, 2009). The ability of these extracts to be sensitive to both Gram positive and Gram negative bacteria is a clear indication of their broad spectrum antimicrobial activity.…”

“…Among the phytochemicals screened for tannins were found to be the most abundant followed by the flavonoids and the saponins. These clearly demonstrates the reason as to why the community uses more than one plant to make a concoction for the treatment of a given disease since they can have some additive or synergistic activity against the pathogens of interest (Elgayyar et al, 2000;Ruttoh et al, 2009).…”

Olive Leaf Extract as a New Topical Management for Oral Mucositis Following Chemotherapy: A Microbiological Examination, Experimental Animal Study and Clinical Trial

“…The MIC value of benzydamine HCl and olive leaf that indicates insignificant difference in antibacterial activity against Gram +ve and Gram -ve bacteria, is also important since Gram -ve bacteria have cell wall impermeable to lipohilic solutes while Gram +ve bacteria are susceptible because it has only an outer peptiodoglycan layer which is not an effective permeability barrier [72].…”

Phytochemical screening and antibacterial investigations of crude methanol extracts of <i>Senna didymobotrya</i> (Fresen.) H. S. Irwin & Barneby

“…Generally, the composition of phytochemical compounds within the same plant species differed from one part to another. These observations clearly demonstrated the reason as to why traditional healers use more than one plant parts to make a concoction for the treatment of a given disease since they have some additive or synergistic activity among various phytochemicals against the pathogens of interest (Addo-Fordjour et al ., 2008;Ruttoh et al ., 2009). Bacterial bioassays: Staphylococcus aureus is a grampositive bacterium that produces staphylococcal enterotoxin (SE) A which is responsible for almost all staphylococcal food poisoning, a form of gastroenteritis (Argudin et al ., 2010).…”