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

Abstract

Aim of this study was to evaluate polyphenols and major and trace elements of Cladanthus arabicus and Bubonium imbricatum, along with their in vitro antibacterial activity against six multidrug resistant Enterobacteriaceae (Escherichia coli S33/16, E. coli S34/16, Proteus mirabilis S32/16, Klebsiella pneumoniae S12/16, Enterobacter cloacae S5/16, and Salmonella 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 B. imbricatum than C. arabicus 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 in vitro antibacterial activity, particularly versus E. coli S33/16 (MIC, 0.125 mg ml⁻¹).

Graphical Abstract

Keywords:

• Bubonium imbricatum
• Cladanthus arabicus
• antimicrobials
• enterobacteria
• polyphenols
• major and trace elements
• heavy metals

Acknowledgements

The authors are very grateful to the program Erasmus + under Grant No.: 2015-1-IT02-KA107-014704 and to CNRST (Centre National de Recherche Scientifique et Technique, Morocco) for financial support.

Disclosure statement

No potential conflict of interest was reported by the authors.