Anti-Quorum Sensing and Antibiotic Enhancement of Allylpyrocatechol and Methyl Gallate

Abstract

In this study, the antibiotic enhancement and quorum sensing (QS) inhibition of allylpyrocatechol (APC) and methyl gallate (MG) isolated from leaves of Piper betle (betel) and leaf shoots of Anacardium occidentale (cashew), respectively, were compared. When applied with streptomycin and tested against Staphylococcus aureus and Pseudomonas aeruginosa, the effect of APC was additive while that of MG was synergistic. In terms of QS inhibition against Chromobacterium violaceum, both compounds were equally effective with violacein inhibition observed at concentrations of 60 μg/mL. We successfully increased the purity of APC in the methanol betel leaf extract from 13.2% to 31.5% w/w through solvent partitioning. This study is the first to document the anti-QS activity of APC, which is comparable to that of MG.

A review on tyrosinase inhibition potential of plant extracts for skin whitening

“…When comparing the two species, Rhizophora apiculata showed considerably high tyrosinase inhibitory potencies in comparison to Rhizophora mucronata where the methanol extract of Rhizophora apiculata leaves showed the IC 50 value of 280 µg/ml. In contrast, the methanol extract of Rhizophora mucronata showed an IC 50 value of 790 µg/ml (Lim et al, 2021).…”

“…In the family Malvaceae, the species Thespesia populnea and Hibiscus tiliaceus showed moderate tyrosinase inhibitory potencies, where methanol extract of Thespesia populnea bark showed the IC 50 value of 190 µg/ml (Perera et al, 2018) while the dichloromethane extract of leaves of Hibiscus tiliaceus showed the IC 50 value of 130 µg/ml. (Lim et al, 2021). Since the leaves and fruit peel of Pouteria torta, as well as leaves, seeds, and bark of Saraca asoca, showed moderate tyrosinase inhibitory potencies, these two plant species contain considerable skin whitening properties; thus, these two species can be used for product development in skin whitening products.…”

“…In comparison, the methanol extract of Sonneratia alba leaves showed an IC 50 value of 650 µg/ml. (Lim et al, 2021). Acetone has a lesser polarity than methanol; thus, it gave a high IC 50 value even for the same plant part of the same species.…”

Inhibition of Pseudomonas aeruginosa quorum sensing by methyl gallate from Mangifera indica

“…The highest QSI was produced by a MG compound. Similarly, MG isolated from other plants like Piper betle (betel), Anacardium occidentale (cashew), and Anacardium occidentale L. (cashew) exhibited anti-Qs activity against C. violaceum 12472 35 , 36 . Additionally, MG displayed QSI activity against other pathogenic strains like Salmonella Typhimurium alone and in combination with marbofloxacin at 30 μg/mL concentration 37 .…”