Phenolic profile, antioxidant and antibacterial activities of Balanites aegyptiaca fruit peel

The Balanites aegyptiaca fruit possesses bioactive properties, which may be attributed to its phenolic compounds. However, identifying these phenolic compounds has become increasingly relevant to understanding such activities. Generally, fruit peel contains high content of phenolic compounds compared with flesh. Therefore, this study aimed to identify the profile of phenolic compounds in B. aegyptiaca fruit peel extract (BAFPE) and evaluate their antioxidant and antibacterial activities.

In this study, the great phenolic and flavonoid contents of 1040 mg GAE/100 g DW and 287 mg CE/100 g DW were detected in BAFPE, respectively. The main phenolic compounds identified by the HPLC analysis of BAFPE were gallic acid, apigenin-7-glucoside, rutin, quercetin, and catechin. The antioxidant activity of BAFPE was assessed by 2,2- diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis-[3-ethyl-benzothiazoline]-6-sulfonic acid (ABTS), ferric reducing antioxidant power (FRAP), phosphomolybdenum complex (PMC) and reducing power (RP) assays. The BAFPE showed an efficient antibacterial activity against five human pathogenic bacterial strains with low minimum inhibition concentration (MIC) values. After 8 to 10 h, every examined bacterial strain was entirely dead in the time-killing curves. The correlation of phenolic compounds and antibacterial activity has been discussed. These findings demonstrated that BAFPE can serve as the free radicals neutralizer and antibacterial agent.