Anti-adhesive activity of Aframomum melegueta major phenolics on lower respiratory tract pathogens

Abstract

Recent studies have raised interest in the potential health effect of Aframomum melegueta, which is related to the phenolic content of its seeds. The methanolic extract of A. melegueta seeds showed a significant anti-adhesive effect against Staphylococcus aureus to lung carcinoma cell line in a concentration-dependent manner. The n-butanol and the chloroform fractions exhibited a significant antiadhesive activity against S. aureus. The chloroform fraction exhibited an antiadhesive effect of 49.53%, 40.15% and 70.34% at concentrations 25, 50 and 100 µg/mL, respectively. Through a biologically guided isolation, the chloroform fraction yielded a new diarylheptanoid identified using 1D, 2D NMR and HREIMS and named 3-(S)-acetyl-1-(4′,5′-dihydroxy-3′- methoxyphenyl)-7-(3″,4″-dihydroxyphenyl)heptane(1), in addition to eight known compounds (2–9). Compounds (1), 6-paradol (5), [6]-shogaol (7), [8]-gingerol(8) and dihydro[6]paradol (9) exhibited a significant anti-adhesive activity against S. aureus with a % of inhibition of adhesion of 60.58, 50, 70.07, 85.4, 59.85% at 50 µg/mL, respectively. Additionally, the extract’s capacity to reduce adhesion without reducing bacterial growth reduces the likeliness of resistance development.

Keywords:

• Aframomum melegueta
• antiadhesive
• diarylheptanoids
• Staphylococcus aureus