Antimicrobial potency of red and yellow varieties of grapefruit (Citrus Paradisi Macfad) grown in Jordan

Main Article Content

Malek A. Zihlif
Fatima Afifi


grapefruit, antimicrobial, microorganisms, Jordan


Introduction: Worldwide, grapefruit is known to have medicinal values with antimicrobial, anti-inflammatory, antioxidant, and astringent propensities. Only a few researchers studied its antibacterial effects underlining the efficacy of the flavonoids extracted from the grapefruit peels against gram-positive and negative bacteria. Aims: The purpose of this work was to evaluate the antibacterial activity of the grapefruit water and ethanol extracts and their furanocoumarins against three common infectious bacteria and their multi-drug resistant clinical isolates. Methods: Antimicrobial activity of 4 different grapefruit extracts (Red-Ethanol, Yellow-Ethanol, Red-n-Hexane, Yellow-n-Hexane) from 2 different varieties (Red & Yellow) along with 4 of its active materials (naringin X, Bergaptol, Bergapten, Bergamottin) have been evaluated in vitro against 7 different bacteria that are frequently incriminated in human infection four of which were ATCC (Salmonella paratyphi, E.coli, Staphylococcus aureus, Pseudomonas) and three clinical bacteria (Pseudomonas aeruginosa drugs sensitive, Klebsiellas pneumonia multi-drug resistant, Pseudomonas aeruginosa multi-drug resistant) by assessing the minimum inhibitory concentration (MIC), using the microdilution method to test the microorganisms. Results: Most of the grapefruit’s tested extracts showed great activity level, including the active materials (Furanocoumarins) of the grapefruit, which showed a strong level of antimicrobial activity against the tested microorganisms, especially against the gram-negatives. Conclusions: The results obtained from this study confirm that the grapefruit extracts had a significant antimicrobial effect on the tested microorganisms, especially the Red-Ethanol extract, which had more activity against gram-negative bacteria, including E.coli, Pseudomonas as well as Pseudomonas aeruginosa drugs sensitive.

Abstract 172 | PDF Downloads 20


1. Izquierdo-Vega JA, Morales-González JA, Sánchez-Gutiérrez M, et al. Evidence of some natural products with antigenotoxic effects. Part 1: fruits and polysaccharides. Nutrients. 2017;9(2):102.
2. Dow CA, Going SB, Chow H-HS, et al. The effects of daily consumption of grapefruit on body weight, lipids, and blood pressure in healthy, overweight adults. Metabolism. 2012;61(7):1026-1035.
3. Murunga AN, Miruka DO, Driver C, et al. Grapefruit derived flavonoid naringin improves ketoacidosis and lipid peroxidation in type 1 diabetes rat model. PLoS One. 2016;11(4):e0153241.
4. Rossi M, Aktar S, Davis M, et al. The Grapefruit Effect: Interaction between Cytochrome P450 and Coumarin Food Components, Bergamottin, Fraxidin and Osthole. X-ray Crystal Structure and DFT Studies. Molecules. 2020;25(14) molecules25143158
5. Zheng H, Zhang Q, Quan J, Zheng Q, Xi W. Determination of sugars, organic acids, aroma components, and carotenoids in grapefruit pulps. Food Chem. 2016;205:112-21.
6. Negi P, Jayaprakasha G. Antibacterial activity of grapefruit (Citrus paradisi) peel extracts. European Food Research and Technology. 2001;213:484-487.
7. Yin X, Gyles CL, Gong J. Grapefruit juice and its constituents augment the effect of low pH on inhibition of survival and adherence to intestinal epithelial cells of Salmonella enterica serovar Typhimurium PT193. International Journal of Food Microbiology. 2012;158(3):232-238.
8. Uysal B, Sozmen F, Aktas O, et al. Essential oil composition and antibacterial activity of the grapefruit (Citrus Paradisi. L) peel essential oils obtained by solvent‐free microwave extraction: comparison with hydrodistillation. International journal of food science & technology. 2011;46(7):1455-1461.
9. Okunowo WO, Oyedeji O, Afolabi LO, et al. Essential oil of grape fruit (Citrus paradisi) peels and its antimicrobial activities. 2013;
10. Adukwu E, Allen SC, Phillips CA. The anti‐biofilm activity of lemongrass (Cymbopogon flexuosus) and grapefruit (Citrus paradisi) essential oils against five strains of Staphylococcus aureus. Journal of Applied Microbiology. 2012;113(5):1217-1227. https://
11. Oyelami O, Agbakwuru E, Adeyemi L, et al. The effectiveness of grapefruit (Citrus paradisi) seeds in treating urinary tract infections. Journal of Alternative & Complementary Medicine. 2005;11(2):369-371.
12. Cvetnic Z, Vladimir-Knezevic S. Antimicrobial activity of grapefruit seed and pulp ethanolic extract. Acta Pharm. 2004;54(3):243- 250.
13. Girennavar B, Cepeda ML, Soni KA, et al. Grapefruit juice and its furocoumarins inhibits autoinducer signaling and biofilm formation in bacteria. International journal of food microbiology. 2008;125(2):204-208. ijfoodmicro.2008.03.028
14. Bernatoniene J, Keraitė R, Masteikova R, et al. A combination of grapefruit seed extract and concentrated cranberry juice as a potential antimicrobial preservative for the improvement of microbiological stability of hypromellose gel. Ceska a Slovenska farmacie: casopis Ceske farmaceuticke spolecnosti a Slovenske farmaceuticke spolecnosti. 2013;62(5):212-219.
15. Oikeh EI, Omoregie ES, Oviasogie FE, et al. Phytochemical, antimicrobial, and antioxidant activities of different citrus juice concentrates. Food science & nutrition. 2016;4(1):103-109.
16. Perez C. Antibiotic assay by agar-well diffusion method. Acta Biol Med Exp. 1990;15:113-115.
17. Alsayed AR, El Hajji FD, Al-Najjar MA, et al. Patterns of antibiotic use, knowledge, and perceptions among different population categories: A comprehensive study based in Arabic countries. Saudi Pharmaceutical Journal. 2022;30(3):317-328. https://doi. org/10.1016/j.jsps.2022.01.013
18. Heisey R, Gorham BK. Antimicrobial effects of plant extracts on Streptococcus mutans, Candida albicans, Trichophyton rubrum and other micro‐organisms. Letters in Applied Microbiology. 1992;14(4):136-139.

Most read articles by the same author(s)

1 2 3 4 5 6 7 8 9 10 > >>