Abstract:
Human skin has a balanced Skin Resident Bacterial Flora (SRBF) which is beneficial for healthy skin maintenance and different factors are responsible for their well-being. Since facial cleansers are such potential factors as a widely used personal care product, their effects on human facial SRBFwere studied in terms of toxicity. A dose- response analysis was performed by exposing Staphylococcus aureus and Staphylococcus epidermidis, which represent human facial SRBF, to a commercially available facial cleanser containing a high number of chemical ingredients, at eight different concentrations from 100 mL L-1 to 0.1 mL L-1. The concentrations were prepared depending on previous data of the average amount of cleanser usage at once. The percentage survivals and the EC50 values calculated according to the bacterial growth were compared to evaluate the toxic effect of the cleanser. The percentage survivals of both the test organisms were decreased with time when increasing the test concentrations.The EC50 values for Staphylococcus aureus were decreased from 2.928 mL L-1 to 0.5717 mL L-1 and the EC50 values for Staphylococcus epidermidis were increased from 1.761 mL L-1 to 19.34 mL L-1 from 24 h to 48 h resulting more toxic effect towards Staphylococcus aureus compared to Staphylococcus epidermidisat the end of the incubation according to the EC50 values.The product was negatively affected on the survival of both the test organisms at higher concentrations without any significant difference in the toxic effect at both the time intervals (P= 0.063) with revealing the necessity of future aspects.
