Antibacterial activity of two extracts from Rubus fruticosus L. against resistant pathogens and their antioxidant potential

One of the most serious threats to public health across the world is the spread of antibiotics resistant pathogens. This situation obliges researchers from all over the world to focus on how they can overcome this obstacle mainly by searching or synthesizing new molecules to neutralize microbes and to overcome the phenomenon of resistance. One of the main reservoirs of potentially active molecules is the plantae kingdom. In this work, we focused on Rubus fruticosus L., a medicinal species which is used traditionally in Algeria to heal respiratory infections. Both of chemical composition and biological activities of essential oils and flavonoids extract were explored. GC-MS analysis of essential oil reveals the Lanceol as the most abundant component (20.22%). HPLC applied on flavonoids extract shows the presence of the gallic acid, gallocatechin, protocatechuic acid, catechin, caffeic acid, rutin, ellagic acid and myricetin. Tests of antioxidant capacity using the DPPH reveals an inhibiting effect which is more important with the flavonoid extract. Otherwise, resistant strains to conventional antibiotics seem to be sensitive to the flavonoids of this species with MICs varying from 2.36 to 75.54 mg/ml. This study indicates that R. fruticosus L. has an important antimicrobial effect, which justifies its potential use in infectious diseases. For many reasons, this species remains poorly studied, further refined studies on its pure secondary metabolites are needed in the perspective of identifying new antimicrobial molecules from this plant.