Abstract
Acne is associated with hyperkeratosis, elevated levels of skin sebum and growth of Propionibacterium acnes (P. acnes) and Staphylococcus aureus (S. aureus). Furthermore, P. acnes promotes inflammation by inducing IL-6 production and oxidative stress. The aim of this study was to assess the antioxidant, anti-inflammatory and antibacterial potential of a hop-CO2-extract with 50% humulone and lupulone. The susceptibility of P. acnes and S. aureus to the hop extract was tested by using the broth microdilution technique. The minimal inhibitory concentrations (MIC) for P. acnes and S. aureus were 3.1 and 9.4 µg/mL, respectively. In addition, the hop extract showed an antioxidative effect with a half maximal inhibitory concentration (IC50) of 29.43 µg/mL as well as additional anti-inflammatory effects by reducing the IL-6 expression (IC50: 0.8 µg/mL). In addition, a gel formulation with 0.3% hop extract (w/w) had antibacterial activity against P. acnes and S. aureus (inhibition zone value: 5.5 mm and 3 mm, respectively) which was significantly superior to the placebo gel. The positive control (a gel with the antibiotic clindamycin) showed an inhibition zone of 9 mm. Due to its antioxidant, anti-inflammatory and antibacterial effects hop extract might be a treatment option for acne-prone skin.
Highlights
Acne is the most common inflammatory skin disease from which 70–95% of all teenagers temporarily suffer
We tested a hop extract rich in humulones and lupulones for its antioxidant and anti-inflammatory effects in human primary keratinocytes (HPKs) and, in addition, we analysed its antibacterial properties. In this process we found antimicrobial activities against both P. acnes and
To test the antioxidant effect of hop extract we used as test system irradiated HPKs, because ultraviolet (UV) radiation induces extensive generation of Reactive Oxygen Species (ROS) in the skin
Summary
Acne is the most common inflammatory skin disease from which 70–95% of all teenagers temporarily suffer. In about 19% acne continues to adulthood [1]. Acne is characterized by hyperactivity of sebaceous glands. Acne shows an epidermal hyperproliferation that causes follicular hyperkeratosis (comedones) and perifollicular inflammation (papules and pustules). The most important pathogen linked to acne-prone skin is Propionibacterium acnes (P. acnes) [2]. P. acnes is a Gram-positive, anaerobic, immobile bacterium that populates skin pores and hair follicles. It grows on sebaceous, greasy skin and uses sebum as nutrient source [3]. Sebum plays a role in the pathogenesis of acne [4], because P. acnes releases lipases, proteases and hydrolases into the sebum which promotes oxidative stress, inflammation and tissue destruction [5].
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
