Acne vulgaris is a common skin disease affecting children and adolescents. The pathogenesis of acne is multifactorial and complex. There are four important factors that cause acne in humans, such as an increase in sebum secretion, keratinization of the follicle, bacteria, and inflammation (Farrar and Ingham 2004).
To overcome the problem of side effects, medicinal plants and marine organisms have been investigated for the treatment of acne. Therefore, we investigated the possibility that they may be effective acne treatments based on the previously known anti-methicillin-resistant
However, there is no obvious report on the antibacterial activity of phlorotannins from brown alga against acne-related bacteria. Therefore, we demonstrated that phlorotannins isolated from
Raw materials and extraction
In late September 2010,
The following bacterial strains obtained from the Korean Collection for Type Cultures (KCTC; Daejeon, Korea) were used as indicator microorganisms in the study:
The antibacterial efficacy was evaluated by disk diffusion assay described by the CLSI (2009). In brief, bacterial strains were cultured in TSB at 37°C until cells reached at an OD 600 nm of 0.5. One hundred microliter of bacterial culture containing approximately 104-105 CFU mL-1 was spread on MHA agar plates. A paper disc (6 mm in diameter) containing 1 mg and 5 mg of each extract was placed in the above MHA plate. After incubating for 24 h at 37°C, the diameter of the inhibition zone was measured on bacterial culture plates. The experiment was carried out three times and the mean values were presented.
Determination of minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs)
The concentration of MeOH extract and its solvent fractions of
Synergistic effects of fucofuroeckol-A (FF) with tetracycline, erythromycin, and lincomycin against Propionibacterium acnes
The interaction between FF and antibiotics including tetracycline, erythromycin, and lincomycin (Sigma Chemical Co., St. Louis, MO, USA) against
FICA = MICA in combination / MICA,FICB = MICB in combination / MICB,FIC index = FICA + FICB
The interaction was defined as synergistic if the FIC index was <1, additive if the FIC index was 1.0, subadditive if the FIC index was between 1.0 and 2.0, indifferent if the FIC index was 2, and antagonistic if the FIC index >2. Synergy was further subclassified as marked (FIC index, ≤0.50) and weak (FIC index, between 0.50 and 1.0).
In all cases analyses were performed in triplicate and data were averaged over the three measurements. The standard deviation (SD) was also calculated. Significance of differences between average MICs for each individual microorganism were determined by Student’s t test at the 95% significance level using SPSS version 12.0 (SPSS Inc., Chicago, IL, USA).
Anti-acne related bacteria activity of Eisenia bicyclis extracts
The antibacterial activity of methanol extract and its solvent fractions are presented in Table 1. The MeOH extract of
[Table 1.] Disk diffusion assay of methanol extract and its solvent-soluble fractions from Eisenia bicyclis against skin-pathogenic microorganisms
Disk diffusion assay of methanol extract and its solvent-soluble fractions from Eisenia bicyclis against skin-pathogenic microorganisms
Measurement of MIC and MBC values of Eisenia bicyclis extract
The MIC values of solvent fractions against acne-related bacteria varied depending on the polarity of the solvent. Among solvent-soluble fractions, the EtOAc-soluble fraction showed the lowest MIC values against acne-related bacteria. The EtOAc-soluble extract could completely inhibit the growth of
[Table 2.] Minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC) of methanol extract and its solvent-soluble fractions from Eisenia bicyclis against skin-pathogenic microorganisms
Minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC) of methanol extract and its solvent-soluble fractions from Eisenia bicyclis against skin-pathogenic microorganisms
MIC value of isolated phlorotannins from Eisenia bicyclis
According to above results, the EtOAc-soluble fraction of
[Table 3.] Minimum inhibitory concentrations (MIC) of phlorotannins isolated from Eisenia bicyclis and antibiotics (tetracycline, erythromycin, and lincomycin) against skin-pathogenic microorganisms
Minimum inhibitory concentrations (MIC) of phlorotannins isolated from Eisenia bicyclis and antibiotics (tetracycline, erythromycin, and lincomycin) against skin-pathogenic microorganisms
Synergic effects between FF and antibiotics against Propionibacterium acnes
As an alternative way, natural materials such as plantderived or marine-derived compounds in combination with traditional medicines against drug-resistant bacteria may be used as an effective approach for restoration of antibiotic activity (Eom et al. 2013). Taylor et al. (2005) reported that green tea components may display synergy with conventional antibiotics against gram-negative bacteria. In addition, the catechin fraction of green tea acted synergistically with ciprofloxacin in a chronic bacterial prostatitis model in the rat (Lee et al. 2005). Based on these reports, the synergistic effect of marine-derived polyphenol on
[Table 4.] Minimum inhibitory concentrations (MIC) and fractional inhibitory concentration (FIC) indices of fucofuroeckol-A in combination with antibiotics used in the treatment of acne
Minimum inhibitory concentrations (MIC) and fractional inhibitory concentration (FIC) indices of fucofuroeckol-A in combination with antibiotics used in the treatment of acne
Tetracycline, erythromycin, and lincomycin have been used for decades to treat acne. However, these antibiotics can cause undesirable side effects, including vomiting diarrhea, sore mouth, and skin redness. In addition, antibiotic-resistant
In an effort to decrease usage of antibiotics and discover an alternative therapeutic agent for treating acne infection, we have screened MeOH extract and its soluble extract from a brown alga
The present study showed significant correlations between anti-MRSA activity and anti-acne-inducing bacterial activity. In general, gram-negative bacteria are more resistant than gram-positive bacteria to treatment with natural anti-bacterial extracts (Afolayan 2003). The higher resistance of gram-negative bacteria than gram-positive bacteria against different antibacterial compounds is generally attributed to differences in their cell wall and outer membrane (Nikaido 1996, McDonnell and Russell 1999). In this study, the EtOAc-soluble extract of
According to Eom et al. (2011), the antibacterial activities of brown algae are related to their total phenolic contents. Marine-derived polyphenols (phlorotannins) are the predominant EtOAc-soluble compound in brown algae (Choi et al. 2010). Among EtOAc-soluble compound, the polyphenol polymers (eckol, PFF, dieckol, and 8,8′-bieckol) exhibited potent antibacterial activities (Nagayama et al. 2002, Isnansetyo and Kamei 2009). We also reported the isolation of six phloroglucinol derivatives from EtOAc-soluble extract of
Eckol (1), PFF (5), and dieckol (6) have previously been reported to exhibit potential antibacterial activity against MRSA (Lee et al. 2008, Choi et al. 2010, Eom et al. 2013). These results are in accordance with those of our study, which found that eckol-type phlorotannins might possess potential anti-bacterial activities. Although several anti-
From our results, it appears that
In conclusion, the antibacterial activity of the phlorotannins from edible marine brown algae
To our knowledge, this is the first report on the antibacterial activity of phlorotannins against acne-related bacteria. The results of the present investigation are expected to contribute to the development of an alternative phytotherapeutic ingredient without any adverse side effects to human body.