Comparison of phenolic and flavonoid contents and antioxidant and antimicrobial properties of olive leaf and fruit extracts (Olea europaea L.) in two different climatic conditions

Zahedi, Mahboobeh; دهقانی کاظمی, مهدی; Beyzaei, Hamid; Esmaeilzadeh Bahabadi, Sedigheh

doi:10.22034/jpr.2024.8430.3342

Comparison of phenolic and flavonoid contents and antioxidant and antimicrobial properties of olive leaf and fruit extracts (Olea europaea L.) in two different climatic conditions

Document Type : Research Paper

Authors

Mahboobeh Zahedi ¹

مهدی دهقانی کاظمی ²

Hamid Beyzaei ³

Sedigheh Esmaeilzadeh Bahabadi ¹

¹ Department of Biology, Faculty of Basic Sciences, University of Zabol, Zabol, Iran

² Department of Biology, Faculty of Science, University of Zabol, Zabol, Iran

³ Department of Chemistry, Faculty of Basic Sciences, University of Zabol, Zabol, Iran

10.22034/jpr.2024.8430.3342

Abstract

In this research, phenolic and flavonoid compounds as well as antioxidant and antimicrobial properties of the fruits and leaves of Olea europaea L. from Zabul and Zahedan were compared. The total phenolic and flavonoid contents were measured by the Folin Ciocalteu and aluminum chloride colorimetry methods. DPPH free radical scavenging method was used to measure the antioxidant properties of the organs. Inhibitory properties of hydroalcoholic extracts were studied against several Gram-positive and Gram-negative pathogenic bacteria and fungal strains. The total phenolic and flavonoid contents ranged from 132±12 to 207±21 mg of gallic acid equivalent per gram and 26.2±2.5 to 34.4±2.5 mg of quercetin equivalent per gram of dried samples, respectively. IC50 values ranged from 5.27±1 to 128.03±14 μg/ml. No inhibitory activity was observed at the highest concentration of the extracts against strains of E. coli, B. cereus, S. epidirmidis, and A. fumigatus. Most of the extracts were able to prevent the growth of Fusarium oxysporum, but the growth of Pseudomonas aeruginosa strain was inhibited only by Zabul fruit extract. There was no obvious relationship between the climatic conditions of the plant's habitat and the total phenolic and flavonoid contents, antioxidant capacity, and antimicrobial properties of the extracts. Consistent with their high antioxidant properties, extracts of Zahedan olive leaf and Zabul olive fruit showed a wider range of inhibitory effects against pathogens and can be used in the treatment of microbial infections and diseases caused by oxidative stress.

Keywords

Olea europaea

Total phenolic content

Total flavonoid content

Antioxidant capacity

Antimicrobial properties

Subjects