Table 2.
Literature review of research on the antimicrobial properties of Kalanchoe spp.
| Kalanchoe sp. | Method | Microbes tested/Gram (+/-) | Results |
|---|---|---|---|
| K. pinnata (Kouitcheu Mabeku et al., 2017) | Leaf methanol and ethyl acetate extracts were tested against Helicobacter pylori in vitro and in the guts of Swiss mice. | Helicobacter pylori (-) | Methanol extract showed a significant anti-Helicobacter activity with MIC and MBC values of 32 and 256 μg mL-1, respectively. Also reduced bacterial load of gastric mucosa. |
| K. pinnata Transgenic and wild-type (Lebedeva et al., 2017) | Leaf aqueous extracts of wild-type and transgenic (cecropin producing) were applied directly to infected wounds. | Wounds were infected with Staphylococcus aureus (+), Pseudomonas aeruginosa (-), or a combination of both. | Both wild-type and transgenic extracts accelerated wound-healing and demonstrated anti-microbial effects, even in comparison to an antibiotic. |
| K. pinnata (Larasati and Wahid, 2016) | Leaf ethanolic extracts tested using microdilution method | Acinetobacter baumannii (-) and S. aureus (+) | Effective against both bacteria. |
| K. laciniata (Iqbal et al., 2016) | Aerial parts in a 60% methanolic extract | S. aureus (+) and Bacillus subtilis (+) | In assays the crude extract was found effective against S. aureus and B. subtilis, with MIC values of 5 and 2.5 mg mL-1, respectively. |
| K. blossfeldiana (Sarkar et al., 2015) | Methanolic extract evaluated against biofilm production | P. aeruginosa (-) | Extract reduced biofilm formation and thickness reduced secretion of virulence factors. Concentrated extract destroyed biofilms. |
| K. pinnata (Pattewar et al., 2013) | Leaf 95% ethanolic, methanolic extracts 60% methanolic, aqueous extracts | S. aureus (+), P. aeruginosa (-), Escherichia coli (-), and fungus Candida albicans | Zones of inhibition, MICs established (30 mg for S. aureus). All extracts showed antimicrobial effects. 60% methanol extracts performed best. |
| K. pinnata (Tatsimo et al., 2012) | Evaluation of methanolic, ethanolic crude extracts, and extract partitions (in ethyl acetate, hexane) | S. aureus (+), P. aeruginosa (-), Salmonella typhi (-) Fungi C. albicans, Candida parapsilosis, Cryptococcus neoformans | Crude extracts displayed strong antibacterial and especially antifungal effects. Ethyl acetate fractions more strongly anti-microbial. An isolated flavonoid showed particularly strong effects. |
| K. pinnata (Biswas et al., 2011b) | Ethanolic extracts used in agar-diffusion method. | Bacillus megaterium (+), B. subtilis (+), S. aureus (+), E. coli (-), P. aeruginosa (-), Shigella dysenteriae (-), S. typhi (-), Vibrio cholera (-) | Bacterial growth was inhibited by extract, expect for, S. typhi, V. cholera. Effects were strongest against E. coli, with a zone of inhibition of 8.2 ± 0.22. |
| K. pinnata (Majaz et al., 2011) | Root extracts of petroleum ether, chloroform, methanol, and water | S. aureus (-), E. coli (-), P. aeruginosa (-) Fungus C. albicans. | Methanolic extracts most effective against all bacteria; no extracts effective against C. albicans. |
| K. pinnata (Okwu and Nnamdi, 2011) | Two flavonoid compounds were isolated and tested directly | P. aeruginosa (-), Klebsiella pneumoniae (-), E. coli (-), S. aureus (-) Fungi C. albicans and Aspergillus niger | Zones of inhibition, MICs established for all bacteria tested. |
| K. pinnata (Nwadinigwe, 2011) | Stem extracts of methanol, water. Agar-diffusion | S. typhi (-), P. aeruginosa (-), S. aureus (+), Bacillus subtilis (+), Fungi C. albicans and A. niger | Bactericidal effects established against B. subtilis and S. aureus, with the methanolic extract showing strong effects. No effects against P. aeruginosa, C. albicans, and A. niger. S. aureus showed the lowest minimum inhibitory concentration (MIC) of 6.29 mg mL-1 in the methanol extract, while S. typhi showed the highest MIC of 9.98 mg mL-1 in the aqueous extract. |
| K. crenata/K. pinnata (Akinsulire et al., 2007) | Methanol, aqueous extracts. Juice from squeezed leaves. Three solvents based on local alcoholic beverages. Agar diffusion, broth dilution methods to determine MIC. | E. coli (-) ATCC 25922, P. aeruginosa (-), K. pneumoniae (-), Shigella flexneri (-), Salmonella paratyphi (-), Citrobacter spp. (-) S. aureus (+) ATCC 25213, Enterococcus faecalis (+), B. subtilis (+) Fungus C. albicans | Methanolic extracts of both species were effective against all tested, though Gram-positive bacteria were more susceptible. Aqueous extracts were less effective. K pinnata water extracts did not affect E. coli, K. pneumoniae, S. paratyphi, Citrobacter. Aqueous for either species did not affect C. albicans. Local solvents were not effective. Leaf juice extract was effective, particularly for K. crenata, against all except C. albicans. |
| K. pinnata (Ofokansi et al., 2005) | Methanolic extracts. Agar-diffusion, checkerboard. | S. aureus (+) ATCC 9637, K. pneumonia (-), P. aeruginosa (-), S. typhi (-), E. coli ATCC 9637 | MIC determined against S. aureus and B. subtilis, K. pinnata demonstrated synergistic antibacterial effects with another plant |
| K. pinnata (Akinpelu, 2000) | 60% methanolic extracts, tested at 25 mg mL-1 | S. aureus (+), K. pneumoniae (-), P. aeruginosa (-), E. coli (-), B. subtilis (-), S. dysenteriae (-), C. albicans | B. subtilis, E. coli, P. vulgaris, S. dysenteriae, S. aureus were growth inhibited. K. pneumoniae and P. aeruginosa were not growth inhibited. |
| K. pinnata (Obaseiki-Ebor, 1985) | Leaf juice extract 5% v/v tested | S. aureus (+), Streptococcus pyogenes (+), E. faecalis (+), E. coli (-), Proteus spp. (-), Klebsiella spp. (+), Shigella spp. (-), Salmonella spp. (-), Serratia marcescens (-), and P. aeruginosa (-) | Bactericidal effects against all demonstrated. |
Almost all antimicrobial work has focused on the species K. pinnata. Table, in part, adapted from review papers: Biswas et al. (2011a), Quazi Majaz et al. (2011), Pattewar (2012), and Rajsekhar et al. (2016).