Polyphenols contents, heavy metals analysis and <i>in vitro</i> antibacterial activity of extracts from <i>Cladanthus arabicus</i> and <i>Bubonium imbricatum</i> of Moroccan Origin

Abstract

Aim of this study was to evaluate polyphenols and major and trace elements of <i>Cladanthus arabicus</i> and <i>Bubonium imbricatum</i>, along with their <i>in vitro</i> antibacterial activity against six multidrug resistant <i>Enterobacteriaceae</i> (<i>Escherichia coli</i> S33/16, <i>E. coli</i> S34/16, <i>Proteus mirabilis</i> S32/16, <i>Klebsiella pneumoniae</i> S12/16, <i>Enterobacter cloacae</i> S5/16, and <i>Salmonella</i> sp S12/14). UV spectrophotometry, ultra-high-performance liquid chromatography coupled to mass spectrometry and inductively coupled plasma mass spectrometry were used to evaluate total polyphenol content, quali-quantitative profile of single polyphenols and inorganic elements of the extract. The antibacterial activity was investigated by standard methods. Twelve polyphenols were identified in both plants and these were more concentrated in <i>B. imbricatum</i> than <i>C. arabicus</i> extracts. High levels of minerals, essential trace elements and tolerable levels of heavy metals (Cd, As and Pb) were found. Furthermore, the extracts showed also a strong <i>in vitro</i> antibacterial activity, particularly versus <i>E. coli</i> S33/16 (MIC, 0.125 mg ml^-1).