Antimicrobial Activity of Stilbenes from Bletilla striata against Cutibacterium acnes and Its Effect on Cell Membrane

Abstract

The abnormal proliferation of Cutibacterium acnes is the main cause of acne vulgaris. Natural antibacterial plant extracts have gained great interest due to the efficacy and safety of their use in skin care products. Bletilla striata is a common externally used traditional Chinese medicine, and several of its isolated stilbenes were reported to exhibit good antibacterial activity. In this study, the antimicrobial activity of stilbenes from B. striata (BSS) against C. acnes and its potential effect on cell membrane were elucidated by determining the minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), bacterial growth curve, adenosine triphosphate (ATP) levels, membrane potential (MP), and the expression of genes related to fatty acid biosynthesis in the cell membrane. In addition, the morphological changes in C. acnes by BSS were observed using transmission electron microscopy (TEM). Experimentally, we verified that BSS possessed significant antibacterial activity against C. acnes, with an MIC and MBC of 15.62 μg/mL and 62.5 μg/mL, respectively. The growth curve indicated that BSS at 2 MIC, MIC, 1/2 MIC, and 1/4 MIC concentrations inhibited the growth of C. acnes. TEM images demonstrated that BSS at an MIC concentration disrupted the morphological structure and cell membrane in C. acnes. Furthermore, the BSS at the 2 MIC, MIC, and 1/2 MIC concentrations caused a decrease in the intracellular ATP levels and the depolarization of the cell membrane as well as BSS at an MIC concentration inhibited the expression of fatty acid biosynthesis-associated genes. In conclusion, BSS could exert good antimicrobial activity by interfering with cell membrane in C. acnes, which have the potential to be developed as a natural antiacne additive.

SK-03-92 Treatment Causes Release of a Lethal Factor Protein That Kills Staphylococcus aureus Cells

“…Many recent prior studies have examined the antibacterial properties of stilbene compounds [12,[38][39][40][41][42][43]. Genome-wide RNA sequencing analysis of resveratrol treated S. aureus cells has shown no significant changes in brpR, brpS, or lrgA transcription [44,45].…”

Combined metabolomics and transcriptomics reveal the secondary metabolite networks in different growth stages of Bletilla striata (Thunb.) Reichb.f.

“…Pharmacological investigations have demonstrated the efficacy of extracts containing stilbene components from B . striata in preventing pulmonary fibrosis, while the antibacterial activity of stilbene against Cutibacterium acnes can be utilized for acne treatment [ 15 ]. The compound militarine belongs to the class of 2-isobutyl malate gluconoxy-benzyl ester, which is derived from 2-isobutyl malate, which is believed to have the effects of improving cognitive function in rats with chronic cerebral ischemia [ 16 ] and relaxing the isolated thoracic aorta rings of rats [ 17 ].…”