Antimicrobial Activity of Pomegranate and Green Tea Extract on Propionibacterium Acnes, Propionibacterium Granulosum, Staphylococcus Aureus and Staphylococcus Epidermidis

June 2015 | Volume 14 | Issue 6 | Original Article | 574 | Copyright © June 2015


Zhaoping Li MD PhD,a,c,d,e Paula H. Summanen MS,a Julia Downes BS,a Karen Corbett BS,a Tomoe
Komoriya PhD,a,e Susanne M. Henning PhD,c,d Jenny Kim MD PhD,a,c,d and Sydney M. Finegold MDa,b,c

aDepartment of Medicine and Research Service, VA West Los Angeles Medical Center, Los Angeles, CA
bDepartment of Microbiology, Immunology and Molecular Genetics, UCLA, Los Angeles, CA
cDepartment of Medicine, UCLA, Los Angeles, CA
dCenter for Human Nutrition, UCLA School of Medicine, Los Angeles, CA
eDepartment of Sustainable Engineering, College of Industrial Technology, Nihon University, Japan

Abstract
We used pomegranate extract (POMx), pomegranate juice (POM juice) and green tea extract (GT) to establish in vitro activities against bacteria implicated in the pathogenesis of acne. Minimum inhibitory concentrations (MIC) of 94 Propionibacterium acnes, Propionibacterium granulosum, Staphylococcus aureus, and Staphylococcus epidermidis strains were determined by Clinical and Laboratory Standards Institute-approved agar dilution technique. Total phenolics content of the phytochemicals was determined using the Folin-Ciocalteu method and the polyphenol composition by HPLC. Bacteria were identified by 16S rRNA sequence analysis. GT MIC of 400 μg/ml or less was obtained for 98% of the strains tested. 64% of P. acnes strains had POMx MICs at 50 μg/ml whereas 36% had MIC >400 μg/ml. POMx, POM juice, and GT showed inhibitory activity against all the P. granulosum strains at ≤100 μg/ml. POMx and GT inhibited all the S. aureus strains at 400 μg/ml or below, and POM juice had an MIC of 200 μg/ml against 17 S. aureus strains. POMx inhibited S. epidermidis strains at 25 μg/ml, whereas POM juice MICs were ≥200 μg/ml. The antibacterial properties of POMx and GT on the most common bacteria associated with the development and progression of acne suggest that these extracts may offer a better preventative/therapeutic regimen with fewer side effects than those currently available.

J Drugs Dermatol. 2015;14(6):574-578.

INTRODUCTION

Acne vulgaris is a prevalent skin disorder that affects more than 80% of adolescents in the United States.1 Four major pathological processes, increased sebum production, altered keratinization of follicular keratinocytes, colonization of the skin by the anaerobic Gram-positive bacterium Propionibacterium acnes, and inflammation have been implicated to be important in the development of acne.1 In addition, colonization by Staphylococcus aureus, Staphylococcus epidermidis, and Propionibacterium granulosum have been implicated in the pathogenesis of acne.2-4 It was reported that S. epidermidis, P. acnes, and P. granulosum, accounted for 95% of all the sequences analyzed of sebaceous follicles of two acne-affected patients.3 The current treatment options for acne are of only modest efficacy. The use of broad-spectrum antibiotics has led to widespread resistance 5,6 and the topical retinoids, currently considered as the first-line treatment of acne, have serious side effects. There is a need and public interest to identify alternative compounds with improved therapeutic properties for acne vulgaris.
Pomegranate juice exceeds the in vitro antioxidant potency of other common commercial fruit juices.7 Pomegranate fruit contains ellagitannins, gallotannins, ellagic acid, and smaller amounts of flavonoids and anthocyanins. The most abundant type of polyphenols in pomegranate juice and pomegranate extracts are ellagitannins.8 POMx extract is a commercially available dietary supplement that is manufactured from the residual material after the first squeezing of the whole pomegranate fruit for juice production.7 Oral feeding of pomegranate fruit extract to mice afforded protection to mouse skin against the adverse effects of UVB radiation by modulating UVB-induced signaling pathways.9 Hydroalcoholic extract based-ointment from pomegranate was reported to improve wound healing in vivo.10 Pomegranate extract has been demonstrated to have antimicrobial activity against Clostridium difficile.11 Investigations using pure bacterial in vitro cultures have shown that pomegranate by-products and punicalagins significantly inhibited the growth of pathogenic clostridia and Staphyloccocus aureus.12
Green tea is derived from the leaves of Camellia sinensis plant. Tea leaves are rich in polyphenols, such as epigallocatechin-3-gallate (EGCG), the major polyphenol in green tea and the most commonly investigated. These polyphenols are maintained