inhibition of protease activity in active treated samples compared to controls viable numbers of bacteria were quantified using columbia blood agar plates supplemented with haemin and menadione aerobes were counted after incubation for 2 days and anaerobes including black pigmenting colonies bpc were counted after incubation at appropriate conditions for 9 days plate counts are expressed as colony forming units cfu per ml and differences between control and active plates are expressed in logs orthosiphon spicatus reduced plate counts of black pigmenting colonies by 2 59 logs compared to the controls each sample was repeated 5 times within the assay unless otherwise stated all extracts were tested in the assay at a concentration of 500 u03bcg ml for each sample all of the values obtained were logged and the means calculated from the log values a 2 tailed t test with unequal variance was then performed an unequal variance analysis was selected as the individual analyses were independent i e the measures were not comparable to one another for each data set p values were obtained and these gave an indication of the reproducibility of the data a table summarising how orthosiphon spicatus performed in the tests is set out below the raw plant material of orthosiphon spicatus was also tested in the plate biofilm assay as well as the extracts described above the raw plant material was prepared through a 250 u03bcm pore size sieve and was tested at 5000 u03bcg ml in the assay the raw material was at least as effective at inhibiting biofilm formation as the previously tested extracts in fact the raw material reduced black pigmenting colonies by 3 86 logs and protease production by 32 65 orthosiphon spicatus powder was tested for inhibition of biofilm formation in a human form of the plate biofilm.