Origanum vulgare L. Essential Oil as a Potential Anti-Acne Topical Nanoemulsion—In Vitro and In Vivo Study

Abstract

Antibiotics are often prescribed in acne treatment; however, Propionibacterium acnes and Staphylococcus epidermidis, the two of the major acne-associated bacteria, developed antibiotic resistance. Essential oils (EOs) present a natural, safe, efficacious and multifunctional alternative treatment. This study aimed to assess the potential anti-acne activity of selected seven EOs commonly used in Mediterranean folk medicine. Antimicrobial activity screening of these oils showed oregano to exhibit the strongest antimicrobial activity with minimum inhibitory concentration (MIC) of 0.34 mg/mL and minimum bactericidal concentration (MBC) of 0.67 mg/mL against P. acnes; and MIC of 0.67 mg/mL and MBC of 1.34 mg/mL against S. epidermidis. The composition of the most effective EOs (oregano and thyme) was determined using gas chromatography-mass spectrometry (GC-MS). Monoterpenoid phenols predominated oregano and thyme EO with thymol percentile 99 and 72, respectively. Thymol showed MIC 0.70 mg/mL against both P. acnes and S. epidermidis whereas MBC was 1.40 and 2.80 mg/mL against P. acnes and S. epidermidis, respectively. Moreover, oregano exhibited the strongest anti-biofilm effect against S. epidermidis with MBIC 1.34 mg/mL and killing dynamic time of 12 and 8 h against P. acnes and S. epidermidis, respectively. Oregano, the most effective EO, was formulated and tested as a nanoemulsion in an acne animal mouse model. The formulation showed superior healing and antimicrobial effects compared to the reference antibiotic. Collectively, our data suggested that oregano oil nanoemulsion is a potential natural and effective alternative for treating acne and overcoming the emerging antibiotic resistance.

An Overview of Micro- and Nanoemulsions as Vehicles for Essential Oils: Formulation, Preparation and Stability

“…Nevertheless, In addition to the aforementioned non-ionic surfactants, an interesting alternative is represented by the tri-block polymeric surfactants. Taleb et al reported the use of Pluronic F127 in the formulation of Origanum vulgare EO NE [74]. It is a surface active non-ionic ABA block copolymer having the following structural formula: (ethylene oxide)97(propylene oxide)69(ethylene oxide)97.…”

“…Although the stability of these systems is a fundamental aspect, the lack of such information in a remarkable number of publications has to be highlighted. In addition, when such information are present, they are reported only for short periods, such as 30 or 60 days [74,106,111], that cannot be considered sufficient to predict their behaviour over time ( Figure 4A). In this respect, some authors used predictive studies about the thermodynamic stability of MEs and NEs.…”

<p>Clinical Assessment of New Topical Cream Containing Two Essential Oils Combined with Tretinoin in the Treatment of Acne</p>

“…The antibacterial activity on the main skin bacteria has been demonstrated by us in vitro while the one against propionibacterium by other researchers. 18 In addition, in a previous study, the essential oil of Origanum vulgare in nanoemulsion, tested in an acne animal mouse model, has been shown to be a potential anti-acne product. 18 The myrtle in previous studies has also shown in vitro a potential anti-acne activity associated with other plant extracts19 or antibiotics.…”

“…18 In addition, in a previous study, the essential oil of Origanum vulgare in nanoemulsion, tested in an acne animal mouse model, has been shown to be a potential anti-acne product. 18 The myrtle in previous studies has also shown in vitro a potential anti-acne activity associated with other plant extracts19 or antibiotics. 19,20 The anti-inflammatory action of the 2 essential oils has been demonstrated in vitro by other authors.…”

Ciprofloxacin loaded castor oil based emulsion: Its antimicrobial, hematotoxicity and soft tissue pathophysiological study in Wister rats

“…Over the years, the quest to solve the problems associated with drug delivery necessitated the development of various means of its delivery. This will foster patient compliance as well as improve the therapetic potentials as well as the bioavailability of the encapsulated drugs without necessarily increasing the concentration [4,5]. On this note, colloids have played a vital role in which series of emulsion have been formulated.…”