Anti-Propionibacterium acnes and the anti-inflammatory effect of Aloe ferox miller components

Acne is a chronic skin disease caused by inflammation led by Propionibacterium acnes (P. acnes) in the pilosebaceous unit. This study investigated whether plant Aloe ferox (AF) components may have anti-P. acnes and anti-inflammatory properties that may serve for acne treatment. Extracts of Aloe ferox (500 g) were prepared by extracting with 4 L volumes of distilled water (AFW), 50% ethanol (AF50), or 95% ethanol (AF95). AF95 was further fractionated with 2 L volumes of ethyl acetate (AF95E), butanol (AF95B) or water (AF95W). The antibiotic potency against P. acnes was determined by the paper disc diffusion method along with measuring minimal inhibitory concentration and minimal bactericidal concentrations. The anti-inflammatory effect of Aloe ferox was determined by measuring TNF-α, IL-1β, IL-6, and IL-8 levels in THP-1 cells co-cultured with P. acnes. Proliferation of P. acnes was inhibited by 25 mg/mL AFW, AF50 and AF95; however, AF95 had the highest anti-P. acnes activity. AF95 and all its fractions (AF95E, AF95 B and AF95W) remarkably reduced P. acnes-induced elevated levels of inflammatory cytokines (TNF-α, IL-1β, IL-6, and IL-8). From these fractions, AF95E had the largest cytokine dampening. In conclusion, extracts of Aloe ferox had anti-P. acnes and anti-inflammatory effects, suggesting that Aloe ferox could be further studied as a potential treatment for acne.