Antibacterial and Synergistic Effect of Phlorotannins Isolated from Eisenia bicyclis against Acne-related Bacteria
- Abstract
- This study was performed to isolate antibacterial substances from brown seaweed, Eisenia bicyclis against acne vulgaris, and to elucidate the antibacterial mechanism against Propionibacterium acnes, acne-causing bacteria. The antimicrobial activities of methanolic extract of E. bicyclis and its organic solvent soluble extracts including n-hexane (Hexane), dichloromethane (DCM), ethyl acetate (EtOAc), n-butanol (BuOH) and water (H2O) extracts were measured through disk diffusion and minimum inhibitory concentration(MIC) assay. The antibacterial activity of E. bicyclis extracts was in the order of EtOAc-, DCM-, BuOH-, Hexane- and H2O-soluble extract according to MIC assay. And, the results of disk diffustion assay were in accordance with the MIC values, because the maximum value was obtained for the EtOAc extract agent, EtOAc-soluble compounds acne-related bacteria, suggesting that the EtOAc-soluble compounds are related with the antibacterial activity against acne-related bacteria.
ii
Finally, six phlorotannins were isolated from the EtOAc-soluble extract, which exhibited the strongest antibacterial activity against acne-related bacteria among the organic solvent-fractionated extracts. According to the comprehensive spectral analyses of fast-atom bombardment (FAB) mass and NMR profiles, the six compounds were identified to be eckol (EK), fucofuroeckol-A (FF), 7-phloroeckol (7P), dioxinodehydroeckol (DD), phlorofucofuroeckol-A (PFF) and dieckol (DE). Among them, FF showed the highest antibacterial activity compared to those of other phlorotannins. The MIC of FF was determined to be in a range from 32 – 128 μg/mL against P. acnes strains. Also, the synergistic effects of FF was assessed in combination with common antibiotics to treat acnes, tetracycline, erythromycin, and lincomycin. FF clearly reversed the high-level erythromycin and lincomycin resistance of P. acnes. The MIC values of erythromycin against P. acnes were dramatically reduced from 2,048 to 1.0 μg/mL in combination with MIC of FF (64 μg/mL). The fractional inhibitory concentration indices of erythromycin and lincomycin were measured from 0.500 to 0.751 in combination with 32 or 64 μg/mL of FF, respectively against all tested P. acnes strains, suggesting that FF-erythromycin and FF-lincomycin combinations exert a weak synergistic effect against P. acnes.
- Issued Date
- 2014
- Awarded Date
- 2014. 8
- Type
- Dissertation
- Publisher
- 부경대학교
- Alternative Author(s)
- Jeong-Ha Lee
- Affiliation
- 대학원
- Department
- 대학원 미생물학과
- Advisor
- 이명숙
- Table Of Contents
- Chapter I. General Introduction ……….…………………………………… 1
1. Background ……………………………..…………....……...……….…… 2
2. An antibiotic resistance of P. acnes …………..…………………….…….. 4
3. Mechanism of an antibiotic resistance of P. acnes …….………………..… 5
4. Prevalence of antibiotic-resistant P. acnes……………..…………………... 8
5. Strategies for overcoming antibiotic resistance of bacteria ….…………... 10
6. The objectives of this study ……………………………………..…….…. 13
Chapter II. Antimicrobial Activity of Methanol Extract and its Fraction of Eisenia bicyclis against Acne-related Bacteria ………..……... 14
1. Introduction …………………………………………………..…..……… 15
2. Materials and Methods ……………………………..……………….…… 17
2.1. Raw materials and extraction ………………...……………………. 17
2.2. Microorganism and culture …………………….……………..……. 19
2.3. Disk diffusion assay ………………………...……..………….……. 20
2.4. Determination of minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) ……………..……... 20
2.5. Determination of polyphenol content …………………………...….. 21
2.6. Statistical analysis ……………………………………………….…. 22
3. Results and Discussion ………………………………………………….. 23
3.1. Antibacterial activity of E. bicyclis extracts against acne-related bacteria …………………………………………….…………….…………. 23
3.2. Measurement of MIC and MBC values of E. bicyclis extracts ………. 30
3.3. Total phenolic content of E. bicyclis extracts …………….………… 32
4. Summary …………………..………..………………………….……….. 35
Chapter III. Purification and Structure Analysis of the Ethyl acetate-soluble Extracts from Eisenia bicyclis ……………………….………... 36
1. Introduction ……………………………….………….……..…………… 37
2. Materials and Methods ……………………………..……………………… 38
2.1. Isolation and fractionization of the EtOAc-soluble extract from E. bicyclis …………………………………………………………….….. 38
2.2. Identification of phlorotannins from E. bicyclis ………………..……. 38
2.3. Antibacterial activity assay ………………………….………….……. 39
2.4. Statistical analysis ……………………………………………………. 39
3. Results and Discussion …………………………………..……………… 41
3.1. Isolation of phlorotannins from E. bicyclis …………………………... 41
3.2. Identification of compounds isolated from E. bicyclis ………………. 44
3.3. Spectroscopic properties of compounds 1-6 isolated from the EtOAc- soluble extract …………….…………………………………..….. 46
3.4. MIC value of isolated phlorotannins from E. bicyclis ………………. 55
4. Summary ………..……………………………………………….….….. 60
Chapter IV. Synergistic Effects between Fucofuroeckol-A and Dioxinodehydroeckol with Antibiotics in the Treatment of Acnes by Propionibacterium acnes …………….……...…… 61
1. Introduction ……………………………………….……………………… 62
2. Materials and Methods ………………………………………..…………… 63
2.1. Synergistic effects of fucofuroeckol-A and dioxinodehydroeckol with tetracycline, erythromycin, and lincomycin against P. acnes ………. 63
2.2. Synergy tests interpretation …………………………………………. 64
2.3. Statistical analysis ……………………………………………………. 64
3. Results and Discussion …………………………………..……………… 65
3.1. Synergistic effects between fucofuroeckol-A, dioxinodehydroeckol and antibiotics against P. acnes ………………………………………... 65
4. Summary………………………………………………………………….... 70
Conclusions ……………………………………….………………………….. 72
References …………………………………………..………………………… 75
Abstract by Korean Language……………………….………………………. 91
Acknowledgements ……………………………………..……………………. 94
- Degree
- Doctor
- Files in This Item:
-
-
Download
Antibacterial and Synergistic Effect of Phlorotannins Isolated from Eisenia bicyclis against Acne-re.pdf
기타 데이터 / 1.64 MB / Adobe PDF
-
Items in Repository are protected by copyright, with all rights reserved, unless otherwise indicated.