Preliminary evaluation of acute cytogenotoxicity of a novel phenylboronic acid derivative; 2-(bromoacetamido) phenylboronic acid using the Allium cepa chromosome aberrations assay

Figures & data

Figure 1. Structure of 2-(bromoacetamido) phenylboronic acid.

Figure 2. Measurement of the length of the test and control onion roots.

Figure 3. Concentration–response curve of 2-BAPBA effect on root growth inhibition. Vertical bars shown the standard deviation.

Table 1. The inhibition effects of various concentration of 2-(bromoacetamido) phenylboronic acid (2-BAPBA) and dimethyl sulfoxide (DMSO) on root growth of A. cepa.

Treatment	Concentration	Mean rootlength (cm ± SD)	Effect of 2-BAPBA on root growth reduction
MMS (positive control) (mg l^–1)	10	0.97 ± 0.21*	0.16
2-BAPBA in (mg l^–1)	3.1	5.01 ± 0.21^a*	0.02
	6.3	4.27 ± 0.53*	0.29
	12.5	2.73 ± 0.59*	1.10
	25	2.33 ± 0.28*	1.26
	50	1.09 ± 0.29*	0.80
	100	0.97 ± 0.34*	0.16
DMSO (%)	0.31	5.03 ± 0.27
	0.63	4.56 ± 0.45*
	1.25	3.83 ± 0.21*
	2.5	3.59 ± 0.44*
	5	1.89 ± 0.21*
	10	1.13 ± 0.18*

^a Only two bulbs roots measured.

* Significantly different from negative control (p < 0.01, independent t-test). SD: standard deviation.

Figure 4. Effect of different 2-BAPBA concentrations on A. cepa root length compared with concurrent DMSO concentrations.

Table 2. Types of chromosome aberrations and % aberrant cells induced by 2-BAPBA in A. cepa at different times and concentrations.

Treatment	Concentration(mg l^–1)	Treatment time	Counted cell number	Mitoticindex ± SD	Fragment	Anaphase bridge	Stickiness	Micronucleus	C-mitosis	Vagrant	Others^a	% ABC ± SD
Negative control	0.31% DMSO	24 h	3620	53.1 ± 1.15	2	2	23	10	9	1	7	2.8 ± 2.00
Positive control	10 mg l^–1 (MMS)		3545	24.3 ± 2.00*	40	32	209	118	62	18	71	63.9 ± 4.73*
2-BAPBA (mg l^–1)	2 × EC(17.8)		3440	13.3 ± 0.58*	12	24	94	68	32	18	39	62.7 ± 2.52*
	EC(8.9)		3600	14.5 ± 1.00*	15	10	51	42	18	9	24	32.4 ± 3.21*
	½EC(4.45)		3328	17.4 ± 2.00*	9	6	43	22	12	–	25	20.2 ± 2.65*
	¼EC(2.23)		3536	20.9 ± 1.53*	–	1	34	19	3	–	9	8.9 ± 2.00
Negative control	0.31% DMSO	48 h	3438	52.2 ± 1.53	2	4	24	12	13	1	8	3.6 ± 1.53
Positive control	10 mg l^–1 (MMS)		3515	21.6 ± 1.00*	46	39	215	126	69	24	77	78.5 ± 2.08*
2-BAPBA (mg l^–1)	2 × EC(17.8)		3271	12.8 ± 2.65*	17	26	106	71	35	20	45	76.2 ± 2.52*
	EC(8.9)		3592	13.9 ± 1.53*	14	14	68	55	19	10	28	41.7 ± 2.52*
	½EC(4.45)		3348	16.4 ± 2.52*	10	6	46	25	16	2	29	24.5 ± 1.15*
	¼EC(2.23)		3346	18.2 ± 1.00*	5	–	39	23	5	1	10	13.6 ± 1.53*

^a Others include: irregular prophase, nuclear abnormalities, pulverizations, binucleated cell, polyploidy, lagging chromosomes in anaphase, prophase nuclease buds, and multipolar cells.

^* Significantly different from negative control (p < 0.01, independent t-test).

Figure 5. Effect of 2-BAPBA at different times and concentrations on the mitotic index and chromosomal aberrations detected by percentage of aberrant cells of treated roots in A. cepa. Vertical bars show standard deviations.

Figure 6. Photomicrographs of squash preparations of root tips of Allium cepa stained with aceto-carmine showing different types of chromosomal aberrations observed in meristematic cells exposed to 2-BAPBA. (a) Normal stages of cell division: (a.1) interphase; (a.2) prophase; (a.3) metaphase; (a.4) anaphase; (a.5) telophase. (b) Normal cell (2n = 16). (c) C-mitosis (2n = 32). (d) Sticky chromosomes. (e) Anaphase bridge. (f) Vagrant chromosome. (g) Multipolar anaphase. (h) Pulverized chromosomes. (i) Micronucleated cell. (j) Binucleated cells. (k) Damaged nucleus. (l) Ghost cell. (m) Polyploid cell. (n) Polar deviation. (o) Anaphase lagging chromosome. (p) Ring chromosomes. Magnification 400×.