Table 1.
Plants and parts of the plants used in this study.
Table 2.
Phytochemical composition and total antioxidant capacity of P. graveolens, P. odoratissimum, and P. zonale hydroalcoholic extracts.
Table 3.
Tentative identification of the most abundant masses in Pelargonium species hydroalcoholic extracts.
Table 4.
Screening of the antimicrobial activity of P. graveolens, P. odoratissimum, and P. zonale methanolic extracts against bacterial and yeast strains of clinical importance using a microdilution assay.
Methanolic extracts are at a concentration of 1000 μg/mL.
Table 5.
Growing inhibitory parameters (MIC, and MBC) of P. graveolens, P. odoratissimum and P. zonale methanolic extracts against bacteria of clinical importance using broth dilution format.
Fig 1.
Representative illustration of the biofilm inhibition by P. graveolens, P. odoratissimum and P. zonale against bacteria of clinical importance.
The plots illustrated the biofilm inhibition of S. aureus ATCC 25923 by (A) P. graveolens, (B) P. odoratissimum, and (C) P. zonale. Biofilm inhibition of S. aureus MRSA 333 by (D) P. zonale, followed by the biofilm inhibition of (E) E. faecalis ATCC 29212 and (F) E. faecalis INSPI 032 by P. graveolens. Finally, biofilm inhibition of (G) E. faecalis ATCC 29212 and E. faecalis INSPI 032 (H) by P. zonale. Biofilm formation values of methanol-water controls and samples were calculated as the percentage of bacteria biofilm formation through the optical density comparison between methanol-water controls/samples and bacterial growth in only medium culture (positive control). Error bars indicate ± SD of two independent experiments. Statistical significance was analysed using a non-parametric Wilcoxon test (95% confidence interval) for comparison between biofilm formation values where: * p-values < 0.05; ** p-values < 0.01; *** p-values < 0.001; and ns: Non-significant p-value.
Fig 2.
Representative illustration of the biofilm eradication by P. graveolens, P. odoratissimum and P. zonale against bacteria of clinical importance.
The plots illustrated the biofilm eradication of S. aureus ATCC 25923 by (A) P. graveolens, (B) P. odoratissimum, and (C) P. zonale. Biofilm eradication of S. aureus MRSA 333 by (D) P. zonale, followed by the biofilm eradication of (E) E. faecalis ATCC 29212 and (F) E. faecalis INSPI 032 by P. graveolens. Finally, biofilm eradication of (G) E. faecalis ATCC 29212 and E. faecalis INSPI 032 (H) by P. zonale. Biofilm formation values of methanol-water controls and samples were calculated as the percentage of bacteria biofilm formation through the optical density comparison between methanol-water controls/samples and bacterial growth in only medium culture (positive control). Error bars indicate ± SD of two independent experiments. Statistical significance was analysed using a non-parametric Wilcoxon test (95% confidence interval) for comparison between biofilm formation values where: * p-values < 0.05; ** p-values < 0.01; *** p-values < 0.001; and ns: Non-significant p-value.
Fig 3.
Raw 264.7 macrophage viability at 48 h upon treatment with the methanolic extracts.
(A) P. graveolens, (B) P. odoratissimum and (C) P. zonale at concentrations of 0, 125, 250, 500 and 1000 μg/mL. The percentage of viability was calculated relative to the control (DMEM media with the dissolvent methanol-water 80:20, v/v). Error bars indicate ± SD of two independent experiments done in quadruplicates.
Fig 4.
Antibacterial effect of P. zonale fractions in S. aureus ATCC 25923 growth.
Fractions 1 to 10 (A) and fractions 1 to 4 (B) were evaluated against S. aureus ATCC 25923 at 800 μg/mL. Growth inhibition of the 14 fractions is expressed as CFU/mL. Error bars indicate ± SD of two independent experiments done in duplicates.
Fig 5.
Overall evaluation of the chemical profile among fractions.
(A) Dendrogram computed from fractions 1 to 10 post solid-phase extraction of P. zonale based on rescaled metabolite areas. Two clusters are observed comprising fractions 1–4 (cluster 1) and comprising fractions 5–10 (cluster 2). (B) Dendrogram based on tentatively identified compounds from fractions 1 to 4. Distances were computed from their structural and physicochemical similarities using ChemMine Tools. Four clusters are observed and are represented in blue (cluster 1), light blue (cluster 2), green (cluster 3) and orange (cluster 4). (C) The relative abundance of each chemical cluster in the fractions was determined by calculating the mean of the normalised areas of all compounds in the cluster. It should be noted that Cluster 5 (yellow), which corresponds to unidentified compounds, has been included.
Table 6.
Tentative identification of metabolites identified in fractions 1–4 in P. zonale in positive ionization mode.