A new study published in Molecules examined anti-bacterial, anti-biofilm and anti-oxidant potential effects of low molecular weight (LMW) peptides (Br-p) isolated from burdock (Arctium lappa L.) roots.

This preliminary study was performed to exclude or confirm the antibiotic activity of the LMW peptides fraction of Arctium or burdock plants. Antibacterial activity was tested against acne strains using diffusion tests, MIC and MBC. The fibroblast cytotoxicity of Br-p was assessed and the selectivity index (SI) value was determined. An active dressing based on chitosan/alginate/genipin was prepared using freeze-drying; the dressing was evaluated for its anti-acne activity.

The results showed that the fraction of 46 Br-p peptides isolated from burdock root with a molecular weight below 5000 Da and theoretic pI (isoelectric point) of 3.67-11.83 had a narrow spectrum of activity against Gram-positive acne bacterial strains. One of the Br-p peptides assessed on MALDI RapidDeNovo was LRCDYGRFFASKSLYDPLKKRR cationic peptide. It was found to be analogous to that contained in A. lappa protein and was matched as a peptide with antibiotic nature. Meanwhile, Br-p did not show toxicity to fibroblasts in the tested concentration up to 10 mg/mL, obtaining CC50 10 mg/mL. The SI value for the tested Propionibacterium strains ranged from 160-320.

The findings confirmed the anti-acne properties of the isolated peptide fraction from burdock root, and pointed towards the possibility of using as an active dressing on the skin.

Source: Molecules. 2020 Apr 27;25(9):E2027. doi: 10.3390/molecules25092027.