Research On A Topical External Antibacterial Agent Mainly Containing Exacts Of Rabdosia Rubescens

In recent years, the widespread use and abuse of antibiotic therapy conferantibiotic resistance to various bacteria strains, so new antibacterial drugs research anddevelopment is urgently needed. Because of its special antibacterial mechanism,tradition Chinese medicine rarely leads to drug resistance. Therefore, researches onantibiotics of tradition Chinese medicine have become the hot topic in the medical andpharmaceutical studies. Rabdosia rubescens, also named as ice grass, is a perennialherbaceous plant of Plectranthus (Lamiaceae). It mainly distributes in Henan andHebei, and the best of that is produced in Jiyuan. Rabdosia rubescens is an herbal rootextract of traditional Chinese medicine used to treat inflammatory diseases and pain.Modern studies have found that Rabdosia rubescens extracts have obviously inhibitioneffect on bacteria, and the major antibiotic compositions of it were oridonin andponicidin which could evidently inhibit the growth of Staphylococcus aureus, Bacillussubtilis and Pseudomonas aeruginosa. The forms of the drug about Rabdosiarubescens mainly include tablets, dropping pills, capsule and injection etc. However,studies on local external antibacterial agents of Rabdosia rubescens have not beendescribed. In this thesis, a local external antibacterial agents mainly containing exactsof Rabdosia rubescens was designed and prepared. The details of the work are asfollowed:1.The extraction and separation processes of Rabdosia rubescens antibacterialingredients were studied, including extracting with80%ethanol, system solventextracting, silica gel column chromatography isolation etc. The results are shownbelow: Total extraction rate was5.29%, and extraction rate of the chloroform partwhich contained3.3%of oridonin was1.23%. And the rate of oridonin was0.042%.2.It is carried on that comparative study of antibacterial effect and the MICs fromeach part. It is proved that the chloroform part of Rabdosia rubescens had significantantibacterial effect on Staphylococcus aureus, Bacillus subtilis Pseudomonas aeruginosa, bacillus thuringiensis and Methicillin-resistant staphylococcus aureus(MASR). The values of MIC were0.78mg/mL,0.78mg/mL,0.39mg/mL, and1.56mg/mL. Oridonin could inhibit the growth of MRSA with the MIC of0.0625mg/mL.3.The percutaneous absorption of external agents not only depends on drugsthemselves, but also on the penetration enhancers to a large extent. To optimize craftof external cream’s formulas, in this study, azone, green gooseberry oil and shea butterwere selected for comparative researches of enhancement effect through transdermalexperiments in vitro. The result showed that green gooseberry oil was the bestselection of transdermal enhancement effects.4.Rabdosia rubescens cream (5%) was prepared with extracts and accessories,such as dimethylsilicone fluid, liquid paraffin, green gooseberry oil, and so on.Guineapigs were employed in the experiments of acute skin irritation and topical anti-inflammation for the cream. The drug was obvious safe and nonirritating for the resultsproved that not only normal skin but also damaged skin of guinea pigs did not emergethe symptoms of red, swollen lesions nor peeled skin after drugs administrated for twoweeks. Hairless guinea pigs whose skin had been infected by Staphylococcus aureuswere used as topical infection model. The successful model was estimated by thetypical lesions and the trace of Staphylococcus aureus in the skin tissue. By beingcontinuous quantitative timing administrated in7d, the typical lesions of red, swollenskin of guinea pigs disappeared, and infectious pathogens were barely detected at thesite of infection. The studies showed the prominent anti-infective activity of the creamfor treatment infection.5.Mini Duroc pigs of being injected MRSA under the scalded skin were used inthe topical anti-infectious researches. The successful model was estimated by thelesions with red, swollen and purulent secretion at the burned site, and the trace ofMRSA in the skin tissue. By being consecutively administrated in12d, the lesions ofred, swollen skin disappeared, the skin became soft in the infection sites, and infectivebacteria of skin tissue was found to reduce gradually by microscopic examination.Data detected by using the test kits displayed that: compared with the control group,SOD content of the sample group significantly raised after1-4d, and the content ofMDA and IL-6reduced. Besides, the changes of growth factors and endotoxin werenot obvious.