Antibacterial Activities of Selected Cameroonian Plants and Their Synergistic Effects with Antibiotics against Bacteria Expressing MDR Phenotypes

Table 1

Plants used in the present study and evidence of their activities.

Plant (family); and voucher number^a	Traditional uses	Parts used	Bioactive or potentially bioactive Components	^bBioactivities of crude extracts
Allium sativum Liliaceae; 44810/HNC	Cardiovascular diseases, intoxication, inflammations [7], fungi and parasitic infections, respiratory diseases, and asthma [8]	Bulbs	Allicine [7]	Antimicrobial: essential oil against Haemonchus contortus [8]
Allium cepa (Liliaceae); 034/UDS	Cardiovascular diseases, intoxication, inflammations, bacterial and fungal infections [7]	Bulbs	Sulfur component [9]	Antimicrobial: crude extract against Ec, St, and Bs [9]
Carica papaya (Caricaceae); 18647/SRF-CAM	Gastroenteritis, oxidative stress, intestinal worms, hepatitis, cancer, and asthma [10]	Seeds, fruits, leaf, and bark	Alkaloids, steroids, triterpenes and flavonoids [11]	Antimicrobial: seeds, fruits, and bark methanol and aqueous extract active against Sa, Ec, Pa, Pv, St, Kp, Ec, and Bs [12]
Buchholzia coriacea (Capparidaceae); 32124/SRF-CAM	Gastroenteritis [7]	Seeds, bark	Alkaloids, anthraquinones, tannins, cardiaques glycosides, flavonoids glycosides, saponines, steroids, steroids terpenes [13],	Antimicrobial: Seeds methanol and aqueous extract against Sa, St, Bc, Ec [13, 14]
Citrus medica (Rutaceae); 65106/HNC	Atheriosclerosis, influenza, infectious diseases, urinary and cholelithiasis, hypertension, dysentery, diarrhea, rheumatism, gout, worms, anemia, seasickness, pulmonary troubles, and intestinal ailments [15]	Fruits	flavonoids, phenolics, glycosides, and steroids [16]	Antimicrobial: fruit extract against Ca, Ck, Tr, Pa, Sf, St, Ec, Sa, Kp, Pv, Bc, Bm, Bs, Bst, Cf, Mm, Pm, Shf, Stm, Sp, and Ng [16]
Cola acuminata (Sterculiaceae); 1729/SRFK	Cellulite, Asthenia, sexual Asthenia, physical and intellectual fatigue, and gastrointestinal infections [17]	Seeds	Alkaloids (colanine or catechin-caffeine, caffeine, kolatine) [17]	—
Garcinia kola (Clusiaceae) 27839/SRF-CAM	Nervous alertness and induction of insomnia, purgative, wound healing, and cancers [18, 19]	Roots, seeds, and latex	kolanone, kolaflavanone, and garciniaflavanone [20, 21]	Antimicrobial: seeds ethanol extract against Sa, Sp, Spn, and Hi [22]; cytotoxicity of fruits crude methanol extract: weak activity on leukemia CCRF-CEM and pancreatic MiaPaCa-2 cell lines [19]
Garcinia lucida (Clusiaceae); 17974/SRF-CAM	Gastrointestinal infections, poison, and cancers [8, 19, 23]	Bark, seeds, and roots	Dihydrochelerithrine, 6-acétonyldihydrochelerithrine, and lucidamine [24]	Antimicrobial: Seeds methylene chloride extract as β-lactamase inhibitor [25]; cytotoxicity of fruits crude methanol extract: weak activity on leukemia CCRF-CEM and CEM/ADR5000 cells and pancreatic MiaPaCa-2 cell lines [19]
Picralima nitida (Apocynaceae) 1942/SRFK	Malaria and fever [26–28], diabetes, inflammation [29, 30], and cancers [19]	Seeds, fruits, leaf, bark, and roots	Akuammicine, akuammidine, akuammine, picracine, picraline pseudo-akuammigine [31]; glycosides, saponins, tannins, flavonoids, terpenoides and alkaloids [32]	Antimicrobial: fruits aqueous, methanol and dichloromethane against PF [31]; root and stem bark (aqueous and ethanol) against Sa, Pa, Ec, and Bs [32]; cytotoxicity of fruits crude methanol extract: weak activity on leukemia CCRF-CEM cell line [19]

^a(HNC): Cameroon National Herbarium; (SRFC): Société des réserves forestières du Cameroun; (UDs): University of Dschang; Microorganisms (Ca: Candida albicans; Ck: Candida krusei; Bc: Bacillus cereus; Bm: Bacillus megaterium; Bs: Bacillus subtilis; Bst: Bacillus stearothermophilus; Cf: Citrobacter freundii; Ec: Escherichia coli; Hi: Haemophilus influenzae; Kp: Klebsiella pneumoniae; Mm: Morganella morganii; Ng: Neisseria gonorrhoeae; Pa: Pseudomonas aeruginosa; Pf: Plasmodium falciparum; Pm: Proteus mirabilis; Pv: Proteus vulgaris; Sa: Staphylococcus aureus; Spn: Streptococcus pneumoniae; Sp: Streptococcus pneumoniae; St: Salmonella typhi; Tr: Trichophyton rubrum; Sf: Streptococcus faeealis; Shf: Shigella flexneri; Stm: Salmonella typhimurium; Sp: Streptococcus pneumonia). ^bScreened activity: significant (S: CMI < 100 μg/mL). Moderate (M: 100 < CMI ≤ 625 μg/mL). Weak (W: CMI > 625 μg/mL). Q: qualitative activity based on the determination of inhibition zone [33].