Antibacterial Components and Modes of the Methanol-Phase Extract from Commelina communis Linn

Abstract

Infectious diseases caused by pathogenic bacteria severely threaten human health. Traditional Chinese herbs are potential sources of new or alternative medicine. In this study, we analyzed for the first time antibacterial substances in the methanol-phase extract from a traditional Chinese herb—Commelina communis Linn—which showed an inhibition rate of 58.33% against 24 species of common pathogenic bacteria. The extract was further purified using preparative high-performance liquid chromatography (Prep-HPLC), which generated four single fragments (Fragments 1 to 4). The results revealed that Fragment 1 significantly increased bacterial cell surface hydrophobicity and membrane permeability and decreased membrane fluidity, showing disruptive effects on cell integrity of Gram-positive and Gram-negative bacteria, such as Bacillus cereus, Enterococcus faecalis, Staphylococcus aureus, and Salmonella enterica subsp., compared to the control groups (p < 0.05). In sum, 65 compounds with known functions in Fragment 1 were identified using liquid chromatography and mass spectrometry (LC-MS), of which quercetin-3-o-glucuronide was predominant (19.35%). Comparative transcriptomic analysis revealed multiple altered metabolic pathways mediated by Fragment 1, such as inhibited ABC transporters, ribosome, citrate cycle and oxidative phosphorylation, and upregulated nitrogen metabolism and purine metabolism, thereby resulting in the repressed bacterial growth and even death (p < 0.05). Overall, the results of this study demonstrate that Fragment 1 from C. communis Linn is a promising candidate against common pathogenic bacteria.

Antibacterial Ingredients and Modes of the Methanol-Phase Extract from the Fruit of Amomum villosum Lour.

“…Based on our recent studies [ 11 , 12 , 13 , 14 ], the M–CE method was employed to extract antibacterial substances from the fruit of A. villosum Lour. Its water loss rate was 73.68% after freeze-drying at −80 °C for 48 h. The extraction yields of the MPE and chloroform-phase extract (CPE) of A. villosum Lour.…”

“…The bacterial strains and media used in this study are shown in Table S7 . The incubation conditions of the bacterial strains were the same as those described in our recent reports [ 11 , 12 , 13 , 14 ].…”

“…The fruit is oval, purplish red when ripe, and brown after dry, with a unique and rich aroma. The antibacterial components in the samples were extracted using the M–CE method, as reported in our recent studies [ 11 , 12 , 13 , 14 ]. Briefly, the fresh samples were washed with water, cut into small pieces of about 1/4 size, and pre-frozen at −80 °C for 8 h. Thereafter, the samples were further freeze-dried, crushed, and extracted with the methanol–chloroform (2:1, v / v , analytical grade, Merck KGaA, Darmstadt, Germany) at a solid-to-liquid ratio of 1:10 ( m / v ) for 5 h. A certain amount of H 2 O (analytical grade) was added, sonicated, and filtered, and then the MPE and CPE were separated using the same equipment and parameters described in our recent reports [ 11 , 12 , 13 , 14 ].…”

“…In order to further explore the antibacterial activity of A. villosum Lour., in this study, we aimed to extract bioactive compounds in the fruit of A. villosum Lour. using the methanol–chloroform extraction (M–CE) method, which has been well established in our laboratory [ 11 , 12 , 13 , 14 ], and to decipher the antibacterial ingredients and modes of the methanol-phase extract (MPE) from A. villosum Lour.…”

The genus Commelina: Focus on distribution, morphology, traditional medicinal uses, phytochemistry, and Ethno-pharmacological activities: An updated literature review

“…Effective antibacterial components were present in the ethyl acetate extract of C . communis Linn, with MICs of 10 mg/mL against Salmonella typhi , Escherichia coli , Staphylococcus aureus , and Staphylococcus albus [ 43 ].…”