Table 3.

Effect of sub-MICs of methanolic extract of Psoralea corylifolia (seed) on inhibition of quorum sensing-regulated virulence factors in P. aeruginosa PAF-79.

Extract concentration (μg/ml)	Elastase activitya	Total proteaseb	Pyocyanin productionc	Chitinase activityd	EPS productione	Swarming motilityf
Control	0.167 ± 0.025	1.039 ± 0.041	3.8 ± 0.25	0.139 ± 0.005	0.886 ± 0.036	48 ± 1.5
100	0.148 ± 0.004 (11.3)	0.938 ± 0.021 (9.7)	3 ± 0.2 (21)	0.114 ± 0.008 (17.9)	0.661 ± 0.015 (25.3)	40 ± 0.5 (16.6)
200	0.140 ± 0.015 (16.1)	0.891 ± 0.030 (14.2)	2.4 ± 0.13 (36.8)	0.07 ± 0.005 (49.6)*	0.525 ± 0.018 (40.6)	33 ± 2 (31.2)*
400	0.115 ± 0.007 (31.1)	0.748 ± 0.014 (28)	2.1 ± 0.082 (44.7)*	0.063 ± 0.007 (54.6)*	0.373 ± 0.012 (57.9)*	24 ± 1.5 (50)*
800	0.090 ± 0.003 (46.1)*	0.515 ± 0.012 (50.5)*	1.6 ± 0.054 (57.8)*	0.051 ± 0.008 (63.3)*	0.292 ± 0.014 (67)*	22 ± 2.5 (54.1)*

^aElastase activity is expressed as the absorbance at OD₄₉₅.

^bTotal protease activity is expressed as the absorbance at OD_600.

^cPyocyanin concentrations were expressed as micrograms of pyocyanin produced per microgram of total protein.

^dChitinase activity is expressed as the absorbance at OD₅₇₀.

^eEPS production is expressed as absorbance at OD₄₈₀.

^fSwarming motility is expressed as diameter of swarm in mm.

All the data are presented as mean ± SD.

^*significance at p ≤ 0.05.

Values in the parentheses indicate percent reduction over control.