Table 2.
Activity and morphological effect of plant extracts and plant-derived compounds on H. pylori.
| Compound | H. pylori Strain(s) | Technic Determining Morphology |
Technic Determining Viability | Main Results Covering the Morphological Transformation of H. pylori | Authors Interpretation | Bibliography |
|---|---|---|---|---|---|---|
| Cranberry extract | NCTC 11637 | SEM | Culture | - Viability ↓ (2 log, 48 h, MIC) - 33% of coccoid forms (48 h, MIC) |
Inhibitory activity | [45] |
| Eugenol Cinnamaldehyde | ATCC 700392 | Light microscopy | Culture | - Total viability ↓ (9 h, MBC or 6 h, 2× MBC) - Viability ↓ (>3 log, 4 h, 2× MBC) - 70% of coccoid forms (4 h, 2× MBC) |
Inhibitory activity | [46] |
| Boropinol A | B128 | SEM | Culture | - Viability ↓ (several times lower OD, 48 h, MIC) - Spiral forms with shorter length and blebbing (24 h, MIC) |
Inhibitory activity | [47] |
| 7-O-Butylnaringenin | ATCC 700392 | SEM | Culture | - Viability ↓ (<3 log, 24 h, MIC) - Coccoid-like cells with irregular shapes (24 h, MIC) |
Inhibitory activity | [48] |
| β-ACPM | ATCC 43504 | TEM | Culture | - Total viability ↓ (18 h, MIC) - Coccoid forms with blebbing, detachment of the outer cell membrane, and membrane invaginations (24 h, MIC) |
Bactericidal activity | [49] |
| Methyl gallate Benzoic acid PGG Paeonol |
ATCC 43504 | Light microscopy | Culture | - Viability ↓ (1–2 log, 48 h, MIC) - Viability ↓ (≥5 log, 48 h, 2× MIC) - 43–52% of coccoid forms (48 h, MIC) - 74–91% of coccoid forms (48 h, 2× MIC) |
Bactericidal activity | [50] |
| DCL from Magnolia sieboldii leaves | ATCC 43504 | SEM | Culture | - Total viability ↓ (36 h, 2× MIC) - Viability ↓ (2 log, 48 h, MIC) - 49% and 94% of coccoid forms (48 h, MIC and 2× MIC, respectively) |
Bactericidal activity | [51] |
| Isocoumarin paepalantine | ATCC 43504 | SEM | Culture | - Total viability ↓ (72 h, MIC) - Spiral forms (72 h, ½× MIC) - Coccoid forms (72 h, MIC) |
Bactericidal activity | [52] |
| Patchouli alcohol | NCTC 11637 | SEM, TEM |
Culture | - Viability ↓ (1 log, 6 h, 2× MIC) - Mix of both spiral and coccoid forms (72 h, sub-MICs) - Coccoid forms with blebbing, cell wall damage, and lysis of the cytoplasmic membrane (1 h, MIC or 2 h, 2× MIC) |
Bactericidal activity | [53] |
| Chrysin (CH) Pinocembrin (P) Galangin (G) Caffeic acid (CA) |
ATCC 43504 | TEM | Culture | - Viability ↓ (4 log, 12 h, FIC of CH+P) - Viability ↓ (3 log, 12 h, FIC of G+CA) - Ghost (degenerative) cells with coccoid-like shape, membrane damage, and membrane vesicles formation (12 h, FIC of CH+P or G+CA) |
Bactericidal activity | [54] |
| Daphnetin | ATCC 43504 | SEM, TEM |
Culture, Fluorescence + CLSM + Flow cytometry (membrane integrity) |
- Spiral forms (72 h, ¼× MIC) - Single coccoid forms (72 h, ½× MIC) - Budding, rough outer membrane, peculiar detachments between membrane and cytoplasm, and numerous membrane vesicles (72 h, ½× MIC) - No membrane permeability and depolarization (24 h, ½× MIC) - DNA damage (24 h, ½× MIC) |
Daphnetin has a potential to be an effective anti-H. pylori agent | [55] |
Symbols: decrease (↓), increase (↑). Abbreviations: Beta-artecyclopropylmether (β-ACPM), dehydrocostus lactone (DCL), 1,2,3,4,6-penta-O-galloyl-β-D-glucopyranose (PGG), confocal laser scanning microscopy (CLSM), scanning electron microscopy (SEM), transmission electron microscopy (TEM), minimal inhibitory concentration (MIC), minimal bactericidal concentration (MBC), fractional inhibitory concentration (FIC), optical density (OD).