Polyprenols of Ginkgo biloba Enhance Antibacterial Activity of Five Classes of Antibiotics

Table 4

Fractional inhibitory concentration (FIC) index used to determine the type of interactions.

Samples	FIC index
	E. coli	S. aureus
A+GBP-1	3	1
C+GBP-1	1	1
G+GBP-1	1	0.5
E+GBP-1	1	1
P+GBP-1	3	0.8

Synergistic effect (0 < FIC index ≤ 0.5). Additive effect (0.5 < FIC index ≤ 1). Indifferent effect (1 < FIC index ≤ 4).