Phenolic Composition, Anti-Biofilm, Anti-Quorum Sensing, Antioxidant and Enzyme Inhibitory Activities of Pteleopsis Suberosa (Combretaceae) Leaves

Abstract

P. suberosa is a multipurpose medicinal plant in West and Central Africa. Fourteen phenolic compounds were identified in the P. suberosa leaves extract using HPLC-DAD and gallic acid (175.10 & PLUSMN;0.42 & mu;g/g) was the most abundant. The total phenolic content was 112.16 & PLUSMN; 0.33 mg GAE/g DW while the total flavonoid content was 36.10 & PLUSMN;0.58 mg QE/g DW. Minimal inhibitory concentration (MIC) values for antimicrobial activity were 0.3125 mg/mL and 1.25 mg/mL on S. aureus and E. faecalis respectively and 2.5 mg/mL and 0.3125 mg/mL on E. coli and S. typhi respectively. Biofilm inhibition evaluated at sub-MIC concentrations revealed that gram-negative biofilms were more susceptible to P. suberosa extract than gram-positive ones and E. coli biofilms were the most susceptible. The extract inhibited violacein production and quorum sensing with inhibition zones varying from 17.0 & PLUSMN;0.5 mm at MIC to 12.0 & PLUSMN;0.1 mm at MIC/4. The extract showed good antioxidant capacity and was more active in the DPPH & BULL; assay than the two standards & alpha;- tocopherol and BHA used. In the ABTS & BULL;+ and CUPRAC assays, the activity of the extract was greater than that of & alpha;-Tocopherol and very close to that of BHA. The extract showed potential to alleviate Alzheimer's disease by inhibiting acetylcholinesterase and butyrylcholinesterase as well as antidiabetic activity by inhibiting & alpha;-amylase and & alpha;-glucosidase. This is an open-access article distributed under the terms of the Creative Commons Attribution -Non Commercial-Share Alike 4.0 License, which allows others to remix, tweak, and build upon the work non commercially, as long as the author is credited and the new creations are licensed under the identical terms.