Biochemical and in silico study of leaf and bark extracts from Aphanamixis polystachya against common pathogenic bacteria

Abstract

Aphanamixis polystachya may be a natural, renewable resource against antibiotic-resistant bacterial infections. The antibacterial activity of A. polystachya leaf and bark extracts was investigated against three antibiotic-resistant bacterial species and one fungus. Methanolic leaf extract showed only limited antibacterial activity but both methanolic and aqueous bark extract showed high antimicrobial activity. In an antioxidant activity test, leaf and bark extracts exhibited 50% free radical scavenging at a concentration of 107.14 ± 3.14 μg/mL and 97.13 ± 3.05 μg/mL, respectively, indicating that bark extracts offer more antioxidative activity than leaf extracts. Bark extracts also showed lower toxicity than leaf extracts. This suggests that bark extracts may offer greater development potential than leaf extracts. The molecular dynamics were also investigated through the simulated exploration of multiple potential interactions to understand the interaction dynamics (root-mean-square deviation, solvent-accessible surface area, radius of gyration, and the hydrogen bonding of chosen compounds to protein targets) and possible mechanisms of inhibition. This molecular modeling of compounds derived from A. polystachya revealed that inhibition may occur by binding to the active sites of the target proteins of the tested bacterial strains. A. polystachya bark extract may be used as a natural source of drugs to control antibiotic-resistant bacteria.

In vitro Antimicrobial and Antioxidant Activity of Meliaceae Plants Collection of Eka Karya Bali Botanic Garden

“…Sultana et al (2009) also found that bark methanol extract of A. polystachya revealed maximum free radical scavenging activity (IC50 5.36 ppm) was much stronger than our results using leaf extract (IC50 916.378 ppm). In line with Krishnaraju et al (2009), A. polystachya bark extracts exhibited better efficacies toward free radical agent compared to vitamin C. This is in accordance with Paul et al (2021) which found that bark extracts offer more antioxidative activity than leaves extracts.…”