Review on the Antibacterial Mechanism of Plant-Derived Compounds against Multidrug-Resistant Bacteria (MDR)

Table 2

Plants reported with antimicrobial activity against MDR bacteria from 2015to 2021.

Plant	Part	Active compound	Mechanism of action	Active against	Findings	Reference
Alkanna tinctoria	Leaves	Alkaloids		MRSA, E. coli, P. aeruginosa, A. baumannii	MIC well diffusion methodMBC model	[73]
		Flavonoids
		Carbohydrates
Rhazya stricta Decne.	Leaves	Alkaloids	Cell membrane disruption	MRSA, E. coli, K. pneumoniae, VRE	TEM analysis	[74]
Holarrhena antidysenterica		Conessine alkaloid	Efflux pump inhibition	P. aeruginosa	MIC model	[75]
					NPN uptake assay
					Active against RND family
Allium sativum L. (garlic)	Fruit	Allicin (sulfur-containing compound)		P. aeroginosa	MIC and MBC models	[76]
					In vivo
Oxalis corniculata	Leaves			MDR Salmonella typhi	MIC and MBC well diffusion methods	[18]
				K. pneumoniae
Coula edulis Baill.	Fruit	Alkaloids, flavonoids, saponin	Efflux pump inhibition	E. coli	MIC and MBC models	[77]
		Cardiac glycosides		K. pneumoniae
Mangifera indica L.	Bark	Carotenoid	Efflux pump inhibition	P. aeruginosa	MIC and MBC models	[77]
		Tannin
		Catechin
		Polyphenol
Citrus sinensis	Peel	Polyphenol	Efflux pump inhibition	E. coli	MIC and MBC models	[77]
		Catechin
		Carbohydrates
Moringa oleifera Lam.	Leaves	Alkaloids,		P. aeruginosaKlebsiella spp.E. coli	MIC and MBC models	[78]
		Polyphenols
		Flavonoids
		Anthraquinones
		Coumarin
		Tannin, saponin
		Terpenes, sterols
Matricaria recutita L.	Flowers			P. aeruginosa	MIC and MBC model	[78]
				Klebsiella spp.
				E. coli
Eleutherine bulbosa (Mill.) Urb.	Bulb extract			S. aureusShigella boydii	MIC and MBC model	[79]
					Time kill study
					TLC-bioautography
Zanthoxylum alatum	Leaves, stem	Fenchol, linalool		E. coliK. pneumoniae	In vitro model	[80]
					MIC
Cinnamomum tamala	Leaves	Cinnamaldehyde		MDR-H. pylori	In vitro model	[80]
Ocimum sanctum L.	Leaves			S. aureus-resistant strains	In vitro model	[80]
					MIC
Zanthoxylum armatum DC.	Fruit			E. faecium	MIC	[81]
				S. aureus	Biofilm and quorum sensitivity assay
				K. pneumoniae	δ-Toxin inhibition
				A. baumannii	Mammalian cytotoxicity study
				P. aeruginosa
Adiantum capillus-veneris L.	Whole plant			E. faecium	MIC	[82]
				S. aureus	Biofilm and quorum sensitivity assay
				K. pneumoniae	δ-Toxin inhibition
				A. baumannii	Mammalian cytotoxicity study
				P. aeruginosa
Artemisia absinthium L.	Aerial parts			E. faecium	MIC	[82]
				S. aureus	Biofilm and quorum sensitivity assay
				K. pneumoniae	δ-Toxin inhibition
				A. baumannii	Mammalian cytotoxicity study
				P. aeruginosa
Martynia annua L.	Fruit			E. faecium	MIC	[82]
				S. aureus	Biofilm and quorum sensitivity assay
				K. pneumoniae	δ-Toxin inhibition
				A. baumannii	Mammalian cytotoxicity study
				P. aeruginosa
Cynodon dactylon (L.) Pers.	Whole plant			MRSA	MIC and MBC models	[82]
				Imipenem-resistant P. aeruginosa
				MDR- salmonella typhi
Ocimum basilicum L.		Phytol, cadinene		A. baumannii	MIC using broth microdilution technique	[83]
				E. coli
Plectranthus barbatus Andrews.		Phytol, camphor, verbenone		A. baumannii	MIC using broth microdilution technique	[83]
				K. pneumoniae
				E. coli
				P. aeruginosa
Rosmarinus officinalis L.		Phytol, camphor, verbenone		A. baumannii	MIC using broth microdilution technique	[83]
				K. pneumoniae
Myrtus communis L.	Seeds	Gallic acid		S. aureus	MIC model	[60]
		Ellagic acid		P. aeruginosa
		Flavonoids		E. coli
		Fatty acid, tannin		S. enteric
Cinnamomum zeylanicum	Leaves	Polyphenol		S. aureus	MIC model	[60]
				P. aeruginosa
				E. coli
				S. enteric
Syzygium legatii Burtt Davy & Greenway.	Leaves			E. coli	MICIn vitro toxicity study using Caco-2 cells	[84]
		Eugenia zeyheri (Harv.) Harv.
Peganum harmala L.		Seeds	Alkaloids					MRSA	MICMTT assay using HEK-293 cells	[85]
	Harman, harmine
	Harmaline, harmalol
Glycyrrhiza glabra L.	Fruit & leaves	Alkaloids, saponin		P. aeruginosa	MIC model	[86]
		Tannin, flavonoids
		Phenols, coumarin, terpenes
Ficus sycomorus L.	Leaves	Flavonoids		A. baumannii	MIC and MBC models	[87]
		Phenols		Resistant S. aureus
Syzigium cumini	Leaves	Alkaloids		MRSAE. coli	MIC and MBC models	[88]
		Flavonoids
		Terpenoids
Punica granatum L.	Peel	Ellagic tannin		P. aeruginosa	MIC and MBC models	[89]
		Ellagic acid
		Gallic acid
Camellia sinensis (green tea)	Leaves			MRSA	MIC model	[90]
Mentha longifolia (L.) L.	Arial part			VRE	MIC model	[90]
Croton macrostachyus hochst. ex Delile.	Leaves	Triterpenes		MRSA	MIC and MBCBroth microdilution method	[91]
		Sterols, polyphenols
		Saponins
Catharanthus roseus (L.) G.Don.	Leaves	Alkaloids, triterpenes		MRSA	MIC and MBCBroth microdilution method	[91]
		Sterols, flavonoids
		Polyphenols
Paullinia pinnata L.	Leaves	Triterpenes		MRSA	MIC and MBCBroth microdilution method	[91]
		Sterols, polyphenols
		Saponins
Anacardium occidentale L.	Leaves	Alkaloids, saponin		E. coliK. pneumoniae	MIC agar well diffusion method	[92]
		Flavonoids, tannin
		Phenol anthocyanin
Thymbra spicata L.	Arial parts	Carvacrol, thymol		E. coli	MIC and MBC microdilution method	[93]
		Camphor
Lawsonia inermis (henna)	Leaves	Alkaloids, terpenoids, phenolic compounds, tannins, steroids, anthraquinones		MRSA ATCC43300	MIC and MBC (agar well diffusion and colorimetric microdilution methods)	[94]
				K. pneumoniae
				ATCC700603
				P. aeruginosa ATCC37853
Azadirachta indica (neem)	Leaves	Alkaloids, terpenoids, phenolic compounds, tannins, steroids, saponins, flavonoids		MRSA ATCC43300	MIC and MBC (agar well diffusion and colorimetric microdilution methods)	[94]
				K. pneumoniae
				ATCC700603
				P. aeruginosa ATCC37853
Piper betle Linn.	Leaves			P. aeruginosa TISTR1287	Agar-disc diffusion method	[95]
					Broth dilution assay (MIC and MBC)
Cistus salviifolius		Hydrolysable tannins, flavonoids (myricetin and quercetin)		MRSA	Disc-dilution method, microdilution method	[96]
Punica granatum		Hydrolysable tannins (punicalin and punicalagin)		MRSA	Disc-dilution method, microdilution method	[96]
Platanus hybrida	Fruits	Phenolic compounds		E. faecium, E. faecalisP. aeruginosa, K. pneumoniae	Kirby–Bauer disc diffusion method	[97]
Syzygium aromaticum	Flower buds			K. pneumoniaeS. aureus	Disc-diffusion method (MIC and MBC), scanning electron microscopy, DNA apoptosis	[98]
Acacia nilotica	Seeds			S. aureus	Disc-diffusion method (MIC and MBC), scanning electron microscopy, DNA apoptosis	[98]

All bacteria strains are multidrug resistant.