Table 4: Determination of antimutagenic activity of Conyza extracts in Salmonella typhimurium TA1535 against sodium azide (NaN3; 2 μg/plate).

Treatment NaN3 mutagenicity at Conyza extract concentrations
(revertant colonies/plate; mean ± SEM (% reduction in NaN3 mutagenicity))
Preexposure*Coexposure*
1 mg/mL5 mg/mL1 mg/mL5 mg/mL

NaN3 (2 μg/plate)290.3 ± 17.1 (0)
I179.0 ± 10.5 (41)a31.3 ± 5.2 (95)a,b286.0 ± 18.0 (4)215.0 ± 18.1 (28)a,b
II129.3 ± 4.2 (59)a11.3 ± 1.9 (102)a,b291.0 ± 21.5 (0)24.0 ± 4.7 (97)a,b
III22.3 ± 2.9 (98)a13.3 ± 1.5 (101)a14.3 ± 2.7 (101)a10.0 ± 1.7 (103)a
IV64.0 ± 5.7 (83)a18.7 ± 3.7 (99)a,b74.0 ± 4.1 (79)a20.7 ± 1.2 (99)a,b
V10.7 ± 1.2 (102)a13.7 ± 1.5 (101)a58.7 ± 8.0 (85)a31.3 ± 6.1 (95)a

Plant extracts were incubated with bacteria either 30 minutes before NaN3 (Preexposure) or incubated with the bacteria and NaN3 (coexposure). The spontaneous revertant colonies were 17.0 ± 2.1. aSignificant (P < 0.05) reduction (% of inhibition of mutagenicity indicated in parentheses) from revertant colonies seen with NaN3. bSignificant difference (P < 0.05) between plant extract concentrations.