Anti-Acne Activity of Italian Medicinal Plants Used for Skin Infection

Abstract

Propionibacterium acnes is implicated in the pathogenesis of acne vulgaris, which impacts >85% of teenagers. Novel therapies are in high demand and an ethnopharmacological approach to discovering new plant sources of anti-acne therapeutics could contribute to filling this void in effective therapies. The aims of our study were two-fold: (1) To determine if species identified in ethnopharmacological field studies as having traditional uses for skin and soft tissue infection (SSTI) exhibit significantly more activity against P. acnes than species with no such reported use; and (2) Chemically characterize active extracts and assess their suitability for future investigation. Extracts of Italian medicinal (for acne and other skin infection) and randomly collected plants and fungi were screened for growth-inhibitory and anti-biofilm activity in P. acnes using broth microdilution methods. Bioactive extracts were chemically characterized by HPLC and examined for cytotoxicity against human keratinocytes (HaCaTs). Following evaluation of 157 extracts from 10 fungi and 58 plants, we identified crude extracts from seven species exhibiting growth inhibitory activity (MICs 64–256 μg mL−1). All active extracts were examined for cytotoxicity against HaCaTs; extracts from one fungal and one plant species were toxic (IC50 256 μg mL−1). HPLC analysis with chemical standards revealed many of these extracts contained chlorogenic acid, p-coumaric acid, ellagic acid, gallic acid, and tannic acid. In conclusion, species used in traditional medicine for the skin exhibited significantly greater (p < 0.05) growth inhibitory and biofilm eradication activity than random species, supporting the validity of an ethnobotanical approach to identifying new therapeutics. The anti-acne activity of three extracts is reported for the first time: Vitis vinifera leaves, Asphodelus microcarpus leaves, and Vicia sativa aerial parts.

Validation of a 16th Century Traditional Chinese Medicine Use of Ginkgo biloba as a Topical Antimicrobial

“…S. pyogenes strains were streaked on TSA + 5% defibrinated sheep blood and incubated at 37 °C at 5% CO 2 , and liquid cultures were made in Brain Heart Infusion (BHI). C. acnes strains were treated as previously described (Nelson et al, 2016).…”

“…The minimum inhibitory concentration (MIC) for extracts was determined according to the CLSI guidelines (CLSI, 2013). For C. acnes , we followed previously described methods with some modifications (Tsai et al, 2010; Nelson et al, 2016). Concentrations of the overnight culture was determined using a Cytation 3 multimode plate reader (Biotek ® , Winooski, VT, United States) by optical density (OD 600 nm ), then was standardized to 5 × 10 5 CFU/mL with CAMHB media (or to 5 × 10 7 CFU/mL in BHI with 1% dextrose for C. acnes ).…”

“…All extracts were examined for biofilm inhibitory activity in four species: A. baumannii , K. pneumoniae , C. acnes , and S. aureus using previously described methods (Quave et al, 2012; Nelson et al, 2016; Muhs et al, 2017). For S. aureus , we used the well-characterized methicillin-sensitive Staphylococcus aureus (MSSA) osteomyelitis strain (UAMS-1), and its isogenic ΔsarA mutant, UAMS-929, which has a biofilm deficient phenotype and serves as a positive control.…”

A Review of the Phytochemistry, Traditional Uses, and Biological Activities of the Genus Ballota and Otostegia

“…resveratrol in the extract. Furthermore, in one case, the demonstration of the lack of antibacterial activity versus Propionicbacterium acnes (Gilchrist) Douglas of Italian B. nigra extract demonstrated the inconsistency of its claimed ethnopharmacological use as an anti-acne remedy [262]. In some cases, the antimicrobial activity of a certain species may vary greatly depending on the extraction solvent and the target investigated.…”

Pesquisa e desenvolvimento de emulsões à base de óleos vegetais (buriti, cenoura e urucum) e bases auto emulsionantes aditivadas de óleo de melaleuca e ácido salicílico para o tratamento de pele acneica

“…Assim, nas placas 1 (experimento 1) e 2 (experimento 2), os valores de CIM obtidos foram idênticos, mas variaram na placa 3 (experimento 3). (MORENO,et al, 2006;NELSON et al, 2016;VIJAYALAKSHMI, TRIPURA, RAVICHANDIRAN;.…”