This study evaluated the in vitro and in vivo antibacterial activity and screened the phytochemical profile of the 80% methanol crude extract from Ehretia cymosa leaves. The extract was prepared from air-dried, powdered leaves via cold maceration, rotary evaporation, and freeze-drying. Antibacterial testing employed disk diffusion and MIC/MBC determinations. An in vivo murine burn-infection model was used to assess wound contraction and epithelialization. Statistical comparisons used one-way ANOVA with Tukey’s post hoc tests. The extract showed dose-dependent antibacterial effects (p < 0.001). MICs ranged from 6.25 to 75 mg/mL; MBC against Pseudomonas aeruginosa and Escherichia coli was 200 mg/mL. In vivo, wound contraction and epithelialization were faster for infections with Staphylococcus aureus than with P. aeruginosa. Phytochemical screening revealed the presence of flavonoids, terpenoids, and tannins. The authors recommend further isolation and characterization of active compounds.
Antimicrobial resistance and adverse effects associated with antibiotics have renewed interest in plant-derived antibacterial agents. Traditional medicinal plants are investigated as sources of novel bioactive compounds that may address resistant pathogens and provide alternative topical therapies for wound infections. Ehretia cymosa, a plant native to Ethiopia and used traditionally for wounds, gastrointestinal complaints, and other conditions, has prior reports of biological activity including antimicrobial effects. The current study aimed to extend earlier in vitro observations by quantifying MIC/MBC values, testing additional strains, and assessing efficacy in an in vivo burn infection model to better approximate therapeutic potential.
Fresh E. cymosa leaves were collected from eastern Ethiopia, washed, shade-dried, and ground to a fine powder. The material was authenticated by a biologist and a voucher specimen (HUHE0000002255 (023551)) was deposited in the Herbarium of the Biology Department at Haramaya University.
For extraction, 600 g of powdered leaf was macerated in 300 mL of 80% methanol. Cold maceration was performed with agitation on a mini-orbital shaker at 120 rpm for 72 hours; the residue was re-macerated twice to maximize yield. Filtration used nylon cloth followed by Whatman No. 1 filter paper under suction. The combined filtrate was concentrated using a low-pressure rotary evaporator (conditions reported in the source) and then freeze-dried to produce a brownish crude extract.
The choice of 80% methanol was based on its polarity, extraction efficiency, and compatibility with analytical techniques; it was selected as a balanced solvent for safety, solubility, and yield.
Antibacterial activity of the crude extract was assessed using the disk diffusion method against bacterial pathogens commonly implicated in wound infections. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values were determined; the reported MIC range for tested strains was 6.25 to 75 mg/mL, and the MBC against P. aeruginosa and E. coli was 200 mg/mL. Activity was reported as dose-dependent and statistically significant compared with controls (one-way ANOVA, Tukey post hoc; p < 0.001).
Specific details regarding the complete panel of bacterial strains tested, individual zone diameters for disk diffusion, or full MIC/MBC tables beyond the reported ranges are not included in the provided source excerpt.
An in vivo model involving a burn followed by bacterial infection was established in mice to evaluate the extract’s effect on wound contraction and epithelialization. The extract-treated wounds showed faster contraction and a shorter epithelialization period when infected with Staphylococcus aureus compared with wounds infected with Pseudomonas aeruginosa. The report indicates that the extract produced measurable benefits in wound healing against S. aureus in this model.
Detailed methodologies for inoculum preparation, topical formulation concentrations, treatment schedules, and quantitative wound-area data were described in the original study but are not fully reproduced in the provided excerpt.
Qualitative analysis of the crude leaf extract identified the presence of flavonoids, terpenoids, and tannins. These classes of secondary metabolites are commonly associated with antimicrobial and wound-healing properties and may underlie the observed antibacterial and in vivo effects.
The source reports these qualitative findings but does not provide chromatographic identification, compound structures, or quantitative concentrations of individual phytochemicals within the extract.
The observed in vitro antibacterial activity and the favorable outcomes in an in vivo wound model support the traditional use of E. cymosa leaves for treating infections and wound conditions. The presence of flavonoids, terpenoids, and tannins provides plausible mechanistic contributors to antibacterial and wound-healing effects, consistent with literature linking these compound classes to antimicrobial activity. MIC and MBC values indicate inhibitory and bactericidal concentrations within the tested ranges, with higher MBC values for Gram-negative organisms reported.
While results are promising, the crude extract is a complex mixture; definitive attribution of activity to individual constituents requires further phytochemical isolation, structural characterization, and mechanism-of-action studies. Additionally, full translation to clinical use would require standardized extract preparation, safety and toxicity profiling, dose optimization, and efficacy studies in larger, regulated preclinical models.
The 80% methanol extract of Ehretia cymosa leaves exhibited in vitro antibacterial activity and improved wound-healing parameters in an in vivo murine burn infection model, corroborating aspects of traditional use. The extract contained flavonoids, terpenoids, and tannins. The authors recommend isolation and characterization of active compounds and further studies to elucidate mechanisms, optimize formulations, and assess safety and efficacy in extended preclinical testing.
Note: Specific experimental details such as complete strain lists, exact in vivo dosing regimens, and comprehensive numerical outcome tables were not fully reported in the provided source excerpt and should be consulted in the original publication for operational replication and deeper analysis.