Pterostilbene, a Methoxylated Resveratrol Derivative, Efficiently Eradicates Planktonic, Biofilm, and Intracellular MRSA by Topical Application

Abstract

Pterostilbene is a methoxylated derivative of resveratrol originated from natural sources. We investigated the antibacterial activity of pterostilbene against drug-resistant Staphylococcus aureus and the feasibility of using it to treat cutaneous bacteria. The antimicrobial effect was evaluated using an in vitro culture model and an in vivo mouse model of cutaneous infection. The minimum inhibitory concentration (MIC) assay demonstrated a superior biocidal activity of pterostilbene compared to resveratrol (8~16-fold) against methicillin-resistant S. aureus (MRSA) and clinically isolated vancomycin-intermediate S. aureus (VISA). Pterostilbene was found to reduce MRSA biofilm thickness from 18 to 10 μm as detected by confocal microscopy. Pterostilbene showed minimal toxicity to THP-1 cells and was readily engulfed by the macrophages, facilitating the eradication of intracellular MRSA. Pterostilbene exhibited increased skin absorption over resveratrol by 6-fold. Topical pterostilbene application improved the abscess formation produced by MRSA by reducing the bacterial burden and ameliorating the skin architecture. The potent anti-MRSA capability of pterostilbene was related to bacterial membrane leakage, chaperone protein downregulation, and ribosomal protein upregulation. This mechanism of action was different from that of resveratrol according to proteomic analysis and molecular docking. Pterostilbene has the potential to serve as a novel class of topically applied agents for treating MRSA infection in the skin while demonstrating less toxicity to mammalian cells.

Wine Phenolic Compounds: Antimicrobial Properties against Yeasts, Lactic Acid and Acetic Acid Bacteria

“…Pterostilbene is a methoxylated derivate of resveratrol originating from natural sources like wine grapes or blue berries. Its potent capability against methicillin-resistant Staphylococcus aureus (MRSA) has been related to bacterial membrane leakage, chaperone protein downregulation, and ribosomal protein upregulation [42].…”

In vivo studies of resveratrol contained in cosmetic emulsions

“…It can be concluded that resveratrol penetrates the epidermis, thus supplementing the lipids of its protective layer. Therefore, during the use of the tested emulsion, the hydration level increased (Yang et al, 2017;Igielska-Kalwat J, Tariq Mahmood, 2018;Vries et al, 2018). Figure 5 presents the average changes in the skin hydration level in the control group.…”

The atopic dermatitis-like lesion and the associated MRSA infection and barrier dysfunction can be alleviated by 2,4-dimethoxy-6-methylbenzene-1,3-diol from Antrodia camphorata

“…The biofilm was treated by DMD, ciprofloxacin, or CPC at a concentration of 500 mg/ml for 24 h. The three-dimensional structure and thickness of biofilm were detected by Leica TSC SP2 confocal microscopy [10].…”