Study On Antimicrobial Activities Of Traditional Chinese Medicine Aqueous Extract To Propionibacterium Acnes In Vitro And Observation Of The Medicine Effects On Rabbit’s Ear Acne Vulgaris Models

Objective: In order to provide optional medicines for clinical treatmentof acne vulgaris. We observed the effects of19kinds of traditional Chinesemedicine (TCM) aqueous extract in vitro on the standard and clinical strains ofpropionibacterium acnes and screened out the effective TCM aqueous extract.Then we applied them externally on rabbit’s ear acne vulgaris models toobserve their effects and side effects. Methods:(1) We collected lesioncontents of acne vulgaris patients and conducted anaerobic cultivation ofpropionibacterium acnes at37°C for forty-eight hours. After tested by oxygenresistance experiment, gram staining microscopy, catalytic test, nitrate test andsugar fermentation experiment as well as tested by ANI anaerobic identificationcard, VITEK fully-automatic microbe instrument, the strains were identified aspropionibacterium acnes.(2) According to the literature, we chose19kinds ofTCM which were clinically used frequently, including Cortex phellodendri,Scutellaria baicalensis, Rhubarb, Sophora flavescens, Honeysuckle, Forsythia,Belvedere fruit, Chinese bulbul, Spreading hedyotis, Houttuynia cordata,Purslane, Yerbadetajo herb, Lithospermum erythrorhizon, Radix isatidis,Folium isatidis, Taraxacum, Semen plantaginis, Angelica dahurica, Fructuscnidii. We weighed each of them20g, soaked them in water, cook, filtered andthen concentrated to20ml TCM aqueous extract (equivalent to the original drugconcentration of1g/ml).(3) We modulated improved GAM culture plates withdifferent concentration of TCM aqueous extracts. Afterwards we used AGARdilution method to test the MIC values of various TCM aqueous extracts, andthen selected the TCM aqueous extracts which have inhibitory effect. At the same time we attempted to know the drug resistance situation ofpropionibacterium acnes by testing the MIC values of4kinds of antibioticswhich is commonly used in the clinical treatment of acne vulgaris.(4)Weselected7twelve-week’s old male rabbits, used Kligman method to moldrabbits’ ear acne vulgaris models. We wiped coal tar at the opening of rabbits’ears tubes with2cm x2cm areas by the frequency of once a day for two weeks.We injected50ul bacterial suspension of the propionibacterium acnes intorabbit’s each ear subcutaneously on the seventh day, the concentration ofpropionibacterium acnes was1.0×108CFU/ml.14ears of rabbits were dividedinto7groups randomly after the molds were finished, two ears per group.6group’s rabbits’ ears of them were wiped TCM aqueous extract respectively,while the last group were wiped physiological saline on one ear and fusidic acidcream on the other ear, once a day. At last, we observed their treatment effectsand adverse reactions respectively on the7th day, the15th day and the21st day.Results:(1)27strains were identified as propionibacterium acnes afterseparation and cultivation from the lesion contents of80acne vulgaris patients,the positive rate of cultivation was33.75%. No statistical difference was foundnot only between gender groups but also between age groups.(2) The MICvalues of Cortex phellodendri, Scutellaria baicalensis, and Rhiubarb were25mg/ml respectively; the MIC values of Sophora flavescens and Honeysucklewere50mg/ml respectively; the MIC values of Forsythia was100mg/ml.13kinds of TCM aqueous extract didn’t produce bacteriostasis at the highestconcentration of200mg/ml including Belvedere fruit, Chinese bulbul,Hedyotis diffusa, Houttuynia cordata, purslane, Yerbadetajo herb, Radix isatidis,Lithospermum erythrorhizon, Folium isatidis, Taraxacum, Semen plantaginis,Angelica dahurica, Fructus cnidii.(3) The MIC50and the MIC90ofMetronidazole were16μg/ml and128μg/ml respectively, and the resistance rateof Metronidazole was78.57%; The MIC50and The MIC90of Clindamycinwere4μg/ml and16μg/ml respectively, and the resistance rate of Clindamycin was28.57%; The MIC50and The MIC90of Azithromycin were2μg/ml and8μg/ml, and the resistance rate of Azithromycin was21.42%; The MIC50andThe MIC90of Roxithromycin were1μg/ml and64μg/ml respectively, and theresistance rate of Roxithromycin was46.42%.(4) After coated with coal tarfor7days, we found the rabbits’ ears turned thickening and hardening, thepores became bulky, opening and intumescent, white comedos and blackcorneous plugs could also be seen.14days later, red inflammatory papules andpustules were found.(5) The rabbits’ ears were wiped with aqueous extract ofCortex phellodendri, Scutellaria baicalensis, Rhubarb, Sophora flavescens,Honeysuckle and Forsythia respectively, we found their ears became thinnerand softer after7days; the swell reclined and even disappeared after14days;the local hair follicles corneous plugs became flattened, pimples and comedosreduced after21days. No adverse effects such as erythema and desquamationwere found. At the same time we found the rabbits’ ear which was wiped withfusidic acid cream the swell disappeared. We didn’t see obvious changes onrabbits’ ear which was wiped with physiological saline. Conclusion:(1)Aqueous extracts of Cortex phellodendri, Scutellaria baicalensis, Rhubarb,Sophora flavescens, Honeysuckle, Forsythia have good inhibitory effects invitro on Propionibacterium acnes.(2) Propionibacterium acnes presentdifferent degrees of resistance to Metronidazole, Clindamycin, Erythromycinand Azithromycin. The resistance of Metronidazole is the highest in4kinds ofantibiotics.(3) Aqueous extracts of Cortex phellodendri, Scutellaria baicalensis,Rhubarb, Sophora flavescens, Honeysuckle and Forsythia have therapeuticaleffects on rabbit’s ear acne vulgaris models.(4) No obvious adversereactions were found after applied externally aqueous extracts of Cortex phellodendri, Scutellaria baicalensis, Rhubarb, Sophora flavescens,Honeysuckle and Forsythia on rabbit’s ear acne vulgaris models.