Antibacterial Activity of Three Medicinal Lasianthus (Rubiaceae) Extracts on Human Resistant Pathogenic Bacteria

Abstract

Aim: To evaluate the activity of medicinal Lasianthus extracts on bacteria and to determine the chemical characters among three medicinal Lasianthus (Rubiaceae) species. Materials and Methods:The phytochemical investigation of L. cyanocarpus, L. hirsutus and L. lucidus were performed using thin layer chromatography and high performance liquid chromatography (HPLC) techniques. Four antibacterial resistant strains including Staphylococcus aureus ATCC 43300 (MRSA), Klebsiella pneumoniae ATCC BAA 1705 (carbapenemase; KPC-producing strain) and Pseudomonas aeruginosa ATCC 27853 (AmpC β-lactamase producing strain) were used. The phytochemical investigation of L. cyanocarpus, L. hirsutus and L. lucidus were performed using thin layer chromatography and high performance liquid chromatography (HPLC) techniques. We also detected the effects of extracts on bacteria by using a scanning electron microscope. Results:The lipophilic extracts from the three plants revealed the terpenoids, coumarin and iridoid. HPLC showed similarities in the chemical profiles of both leaf and stem bark extracts. L. lucidus lipophilic extracts revealed the greatest effect against S. aureus and P. aeruginosa at 400 and 100 µg/mL respectively, whereas L. cyanocarpus extracts prominently affected K. pneumoniae at 400 µg/mL. Cell lysis and leakage of bacteria treated with extracts were observed. Conclusion:Our findings surprisingly showed the potential of antibacterial effect among resistant pathogenic bacteria. We also revealed the comparable signals of the chemical characters from the three Lasianthus. These findings support the traditional use related infectious diseases and it might be possible to further develop the antibiotic agents.

Changes in cellular elasticities and conformational properties of bacterial surface biopolymers of multidrug-resistant Escherichia coli (MDR-E. coli) strains in response to ampicillin

“…Investigations of the antibacterial activity of β-lactams on susceptible bacterial strains using biochemical techniques ( Kumarasamy et al, 2010 , El Seedy et al, 2017 ), scanning electron microscope (SEM), ( Hartmann et al, 2010 , Napiroon et al, 2017 ), and transmission electron microscope (TEM) ( Hartmann et al, 2010 , Bæk et al, 2014 , Napiroon et al, 2017 ) is well documented in the literature. For example, biochemical techniques such as polymerase chain reaction (PCR) could assess specific resistance genes that may be expressed in antibiotic-resistant bacteria upon exposure to antibiotics ( Fluit et al, 2001 , Kumarasamy et al, 2010 ).…”

“…These include: (1) the need for large samples of organisms to provide reliable sensitivity; (2) lots of samples are discarded in the medium during the RNA preparation; and (3) each antibiotic to be investigated requires an individual assay ( Cockerill, 1999 ). In comparison, both SEM and TEM could directly depict the bacterial cell envelope and clearly show morphological changes in the single cell and cell colonies in response to antibiotics ( Hartmann et al, 2010 , Bæk et al, 2014 , Napiroon et al, 2017 ). However, despite the high resolution of these imaging techniques, they require multiple sample preparation steps before and after exposure to antibiotics that can dry the bacterial cell and induce damage to the cell membrane leading to misinterpretation of bacterial surface structure change resulting from exposure to antibiotics ( Beniac et al, 2014 , Golding et al, 2016 ).…”