Abstract

Background:
Opuntia spp. are prickly pear cactus species that have long been used for medical purposes. Mature cladodes are also used to feed animals during droughts.

Aim:
The phytochemical and chemical composition of cladode extracts from Opuntia streptacantha and thornless Opuntia ficus indica cultivated in Al-Zawia-Libya and to evaluate their antibacterial activity through both in vitro assay and molecular docking analysis.

Methods:
Cladode extracts from two Opuntia species cultivated in Libya were analyzed in this study to compare their chemical composition and evaluate their antibacterial properties explained by structure-function relationships studies.

Results:
The ethanolic extract of O. streptacantha registered the highest total polyphenolic content, total flavonoid content, and tannin contents (112.00 ± 0.58 mg GAE/g, 64.67 ± 0.88 mg CAT/g, and 0.408 ± 0.046 mg CAT/g, respectively). The ethanolic extract of thornless O. ficus-indica exhibited strong antibacterial activity against several bacterial strains, particularly colistin-resistant Escherichia coli. Rutin and luteolin-7-O-glucoside interact with key active-site residues, including the catalytic residues Thr285 and His395.

Conclusion:
Opuntia spp. cultivated in Libya are a valuable source of biomolecules with significant antibacterial properties and may be exploited as a functional food.

Key words: Phytochemical; Opuntia spp.; Molecular docking; Antibacterial.