Table 4.

Toxicity and mutagenicity of CYN/MC-LR in L5178YTk^+/− cells after 4 h with S9 fraction by the mouse lymphoma thymidine-kinase assay (MLA) (n = 2). ^a: Total mutant frequency divided into small/large (S/L) colony mutant frequencies. The induced mutant frequency (IMF) was determined according to the formula IMF = MF-SMF, where MF is the test culture mutant frequency and SMF is the spontaneous mutant frequency. *** p < 0.001.

Concentration (µg/mL)	Relative Total Growth		Percent Plating Efficiency		Mutant Frequency (× 10−6)		MF (S/L) a		IMF (MF-SMF) (× 10−6)
	Experiment 1	Experiment 2	Experiment 1	Experiment 2	Experiment 1	Experiment 2	Experiment 1	Experiment 2	Experiment 1	Experiment 2
0	100	100	93	102	155	146	96/59	82/64	-	-
0.04 CYN-0.4 MC	96	84	82	84	94	100	43/51	42/58	−61	−46
0.08 CYN-0.8 MC	82	72	91	91	95	95	50/45	50/45	−60	−51
0.16 CYN-1.6 MC	58	51	95	100	98	95	48/50	49/47	−57	−51
0.33 CYN-3.3 MC	58	56	102	100	98	105	56/43	60/45	−57	−41
0.67 CYN-6.7 MC	26	31	118	113	120	132	62/58	77/55	−35	−14
1.35 CYN-13.5 MC	16	16	130	116	70	91	29/41	38/53	−85	−55
CP (3 µg/mL)	99	81	65	73	480 ***	433 ***	228/252	213/220	325	286

Positive controls: methylmethanesulfonate, MMS 10 μg/mL without S9 fraction and cyclophosphamide, CP 3 μg/mL with S9 fraction.