The Inhibitory Effects of Aqueous Extract from Guava Twigs, Psidium guajava L., on Mutation and Oxidative Damage

Table 6

The antimutagenicity of the aqueous extract of guava twigs (GTE) toward S. typhimurium TA98 and TA100.

Sample (mg/plate)	His^+ revertants/plate (% of inhibition)
	TA98 + 4-NQO	TA100 + 4-NQO
0	456 ± 32 (0)^d	1848 ± 55 (0)^d
2	330 ± 13 (30)^c	1338 ± 54 (31)^c
5	144 ± 7 (75)^b	1049 ± 47 (48)^b
10	97 ± 6 (87)^a	632 ± 35 (74)^a
	His^+ revertants/plate (% of inhibition)
	TA98 + 2-AA + S9	TA100 + 2-AA + S9
0	534 ± 43 (0)^d	1780 ± 142 (0)^d
2	270 ± 19 (54)^c	1326 ± 86 (28)^c
5	158 ± 14 (74)^b	717 ± 32 (65)^b
10	120 ± 11 (82)^a	491 ± 27 (78)^a

Data represent means ± SD for 𝑛=3. 4-NQO, 4-nitroquinoline N-oxide. 2-AA, 2-anthramine. Values with different superscripts in a column are significantly different (𝑃<0.05). % of inhibition =(1−((no. of revertants with mutagen and sample − no. of spontaneous revertants)/(no. of revertants with mutagen − no. of spontaneous revertants)))×100. The number of spontaneous revertants was determined without samples and mutagen.