Research On Screening, Mechanism And Efficacy Of Chinese Herbals In Cosmetic Inhibition Of Demodex

Human Demodex is a permanent parasite mite which parasites in the skin of healthpeople. The infection rate of human demodex is ranged from0.8%to91.8%. It mainlyparasitizes in the position which has strong sebaceous gland on human face, which mayaffect people’s health and beauty seriously, thus it has been widely concerned. Accordingto the pathopoiesia way of demodex, this article concludes3levels to inhibit humandemodex, as follows. First, hold up sebaceous gland from excreting overabundant lipidwhich can prevent forming the environment advantaged for demodex breed. Second,enhance skin’s safeguard itself, inhibit skin surface bacteria and raising theresponsiveness of T-cell. It can prevent to cause lesion by the infection of both demodexand bacteria when the body’s immunity gets weak. Third, cut the metabolism of demodexby biological method which can lead demodex to death. Specific to the inhibitionpathways that mentioned above, this article did the cosmetic demodex inhibitionscreening, the mechanism study and the functional test to20bacteriostatic Chinese herbs.1. Stability under original status was tested by observing solution’s color, smell,clarity, soluble solid and pH in20kinds of herbs. It was discovered that3kinds of herbextracts appear instability such as changing of color and precipitated under normaltemperature.2. Safety test, including irritant, anti-allerge and anti-irritant, was proceeded byusing normal/modified RBC hemolysis experiment and hyaluronidase in vitro inhibitionexperiment in17kinds of herbs.2kinds of herb extracts were found having irritant lagerthan15%, and coupling with slight hemolysis.3. Chitinase inhibition experiment which can replace in vitro demodex test wasestablished. Good correlation between this method and in vitro demodex test was verified.Functions of15kinds of herbs were tested by transparent circle method and DNScolorimetric method in chitinase inhibition experiment. Rhubarb, hairyvein agrimony,muwort leaf got high inhibition of88.9%,77.5%,70.2%respectively. Bacteriostaticactivities were tested by Oxford cup method. Four kinds of skin bacteria Staphylococcusaureus Rosenbach, Staphylococcus Epidermidis, Propionibacterium acnes and Malasseziafurfur were included in this test. The result shows, rhubarb, golden cypress and radixsophorae flavescentis had inhibition in all of4kinds of bacteria. In conclusion ofdemodex and bacteria inhibition, rhubarb was chosen as the best herb for demodex inhibition material.4. Primary mechanism research of anthraquinone in rhubarb extraction wasdeveloped.5anthraquinones were analyzed by HPLC. The result showed the contents ofaloeemodin, rhein, emodin, chrysophanol and physcion were0.4mg/g,1.2mg/g,0.1mg/g,0.8mg/g and0.4mg/g respectively. Chitinase inhibition experiment was processed toanthraquinones. Aloeemodin has the best inhibition rate of92.53%, while values of theother four were below85%. Bacteria inhibition test was proceeded to anthraquinones. Allof5anthraquinones have the ability to inhibit Staphylococcus aureus Rosenbach,Staphylococcus Epidermidis and Propionibacterium acnes. The experiment shows the5anthraquinones were existed in rhubarb and they were the main components in inhibitingdemodex and bacteria.5. Mechanism research of demodex inhibition was carried out by inhibiting oilsecretion, improving immune system response and in vitro demodex inhibition of rhubarbextraction. It was discovered rhubarb extraction can inhibit oil secretion on oily and mixmodel skin. When concentration of rhubarb extraction was2.5%, inhibition of oilsecretion was31.1%. Rhubarb doesn’t have ability to improve body immune system, onthe other side; it can inhibit cell multiplication when concentration exceeds5%. Positiverelationship was determined between in vitro demodex inhibition and concentration ofrhubarb. Inhibition can reach84%when50%rhubarb affected2h. It was proved thatextract of rhubarb has the effect of inhibition to demodex. However it can not increasethe protection of skin itself.In conclusion, compare to the traditional in vitro demodex inhibition experiment theestablished chitinase inhibition experiment was a fast and convenient method to test thedemodex inhibition function. The rhubarb extract which was screened by stability, saftyand function can be used as raw material of demodex inhibition. The primary research ofthe demodex inhibition activity in five anthraquinones provided a good theory guide forthe deep study of demodex inhibition mechanism. The research of the demodex inhibitionpathway in rhubarb extends the thinking in developing demodex inhibition cosmetic inthe future.