Phytochemical screening, antioxidant, Antimicrobial and Fungicidal Activities of Nerium oleander L.
Phytochemical screening, antioxidant, Antimicrobial and Fungicidal Activities of Nerium oleander L.
- Author(s) Nassim Zouaoui1,2, Nassima Azizi1,3 , Hanane Seghier1,3 Hayette Bouabida1,3* and Selma Ferhi1,4
- Year: 2026
- Month: January
- Volume: 67
- Pages: 23-36
We did phytochemical screening of Nerium oleander L.,ethanolic and aqueous extracts, to
determine the content of total polyphenols and flavonoids, to test their in-vitro antioxidant activity
by DPPH radical scavenging and antimicrobial activity using the disk diffusion method. The plant
contained flavonoids, gallic tannins, catechol tannins, saponins and terpenes. The total polyphenols
and flavonoids contents ranged from 65.321±4.93 mg GAE/g to 11.753±0.92 mg QE/g for the
aqueous extract and 88.25±3.25 mg GAE/g to 10.035±0.34 mg QE/g for the ethanolic extract,
respectively. N. oleander extracts had higher antioxidant activities (from 33.38±2.88 aqueous and
10.97±1.66 μg/mL for ethanolic). The antimicrobial properties of N. oleander extracts were
evaluated against 3-Gram-negative bacteria (Escherichia coli, Pseudomonas aeruginosa and
Serratia marcescens), 2-Gram-positive bacteria (Staphylococcus epidermidis and Staphylococcus
aureus) and 2-fungal species (Candida albicans and Candida parapsilosis). Both ethanolic and
aqueous extracts demonstrated significant antimicrobial activity against all tested strains, except the
Serratia marcescens. The ethanolic extract of N. oleander showed the highest antimicrobial activity,
with inhibition zones of 15-17 mm against the most sensitive isolates. The lowest minimal
inhibitory concentration (MIC) of 39 μg/mL was observed for the ethanolic extract against C.
albicans, while the aqueous extract had an MIC of 78 μg/mL against P. aeruginosa.
