Chemopreventive Activity of 80% Methanol Leaf Extract of Vernonia auriculifera Hiern (Asteraceae) Against Dimethylhydrazine-Induced Colorectal Carcinogenesis in Rats

Figures & data

Table 1 Parameters Showing Induction of Colorectal Cancer by Dimethylhydrazine After 25 Weeks

Parameters	Groups
	Normal Control	DMH20
Average no. of tumor	0.00	4.00 ± 0.52***
Tumor size (mm^3)	–	125.00 ± 34.33***
Tumor incidence (%)	0.00	100
TG (mg/dl)	59.82 ± 4.25	89.25 ± 8.0**
TCHOL (mg/dl)	55.57 ± 1.24	71.43 ± 5.84*
TP (mg/dl)	6.54 ± 0.08	5.60 ± 0.14*

Notes: Data are expressed as mean ± standard error of the mean (SEM); n=6; DMH20, negative controls treated with 20 mg/kg of dimethylhydrazine; TG, triglyceride; TCHOL, total cholesterol; TP, total protein; *p<0.05; **p<0.01; ***p<0.001 compared to normal control.

Figure 1 Representative macroscopic appearance of the colorectum with and without tumors; Dimethyl hydrazine treated group (A), Normal Control (B). The black arrows indicate the tumors on the epithelium of colorectum.

Table 2 Effect of Vernonia Auriculifera on Number and Size of Tumors in Colon and Rectum of Dimethylhydrazine-Treated Rats

Groups	No. Rats Examined	No. Rats with Tumor	Total No. of Tumor	Average No. of Tumor	Tumor Size (mm^3)
DMH20	6	6	26	4.33 ± 0.42	138.33 ± 26.25
ASA60	6	2	2	0.33 ± 0.21^a*	29.50 ± 18.66^a*
Pre-Initiation phase
PIV100	6	4	14	2.33 ± 0.84	42.83 ± 20.56
PIV200	6	4	12	2.00 ± 0.63	34.17 ± 10.98^a*
PIV400	6	3	4	0.67 ± 0. 33^a*	35.00 ± 21.60^a*
Post-Initiation phase
POV100	6	4	24	3.33 ±1.67	46.67 ± 15.84
POV200	6	4	13	2.17 ± 0.91	35.00 ± 11.97^a*
POV400	6	4	4	0.67 ± 0. 33^a*	36.66 ± 16.5^a*

Notes: Data are expressed as mean ± standard error of the mean (SEM); n=6; a: compared to DMH20; ASA60, Aspirin 60 mg/kg; DMH20, dimethylhydrazine 20 mg/kg; PIV and POV; Pre-initiation and Post initiation V. auriculifera at 100, 200, and 400 mg/kg, respectively; *p<0.05.

Figure 2 Dose-response curve of the extract in tumor number reduction for the pre-initiation (A) and post-initiation (B) phases.

Table 3 Effect of Vernonia Auriculifera on Tumor Incidence in Dimethylhydrazine-Treated Rats

Groups	No. Rats Examined	No. Rats with Tumor	Tumor Incidence (%)
DMH20	6	6	100
ASA60	6	2	33.33
Pre-Initiation phase
PIV100	6	4	66.67
PIV200	6	4	66.67
PIV400	6	3	50
Post-Initiation phase
POV100	6	4	66.67
POV200	6	4	66.67
POV400	6	4	66.67

Notes: n=6; ASA60, Aspirin 60 mg/kg; DMH20, dimethylhydrazine 20 mg/kg; PIV and POV; Pre-initiation and Post initiation V. auriculifera at 100, 200, and 400 mg/kg, respectively.

Table 4 Effect of Vernonia Auriculifera on Body Weight Gain and Growth Rate of Experimental Rats

Groups	% Body Weight Gain	Growth Rate
NC	180.62 ± 18.44	1.27 ± 0.13
DMH20	91.47 ± 10.84	0.67 ± 0.08
ASA60	120.00 ± 13.26^b*	1.01 ± 0.08
Pre-initiation phase
PIV100	109.33 ± 11.28^a*	0.84 ± 0.07^a*
PIV200	107.52 ± 4.06 ^a*	0.83 ± 0.03^a*
PIV400	123.80 ± 7.26 ^b*	0.99 ± 0.03
Post-initiation phase
POV100	96.56 ± 11.23^a**	0.78 ± 0.12^a**
POV200	92.32 ± 18.08^a**	0.75 ± 0.14 ^a**
POV400	102.26 ± 10.92^a**	0 0.79 ± 0.064^a*

Notes: Data are expressed as Mean ± SEM (n=6); Analysis was performed by one-way ANOVA; ^aCompared to normal control; ^bCompared to DMH20; NC, normal control; ASA60, Aspirin 60 mg/kg; DMH20, dimethylhydrazine 20 mg/kg; PIV and POV; Pre-initiation and Post initiation V. auriculifera at 100, 200, and 400 mg/kg, respectively *p<0.05; **p<0.01.

Table 5 Histopathological Classification of Tumors Induced by Dimethylhydrazine in the Various Groups

Groups	Tubular Adenoma	Villous Adenoma	Tubulovillous Adenoma	Invasive Adenocarcinoma
DMH20	5	–	–	21
ASA60	2	–	–	–
Pre-Initiation phase
PIV100	5	-	5	4
PIV200	5	-	7	-
PIV400	4	-	-	-
Post-Initiation phase
POV100	8	2	2	10
POV200	9	1	2	1
POV400	3	3	-	-
Total	41	6	16	36

Notes: ASA60, Aspirin 60 mg/kg; DMH20, dimethylhydrazine 20 mg/kg; PIV and POV; Pre-initiation and Post initiation V. auriculifera at 100, 200, and 400 mg/kg, respectively.

Figure 3 Photomicrographs showing hematoxylin and eosin stained normal colon and tumor pathological sections taken from Normal Control, DMH20, PIV100, PIV200, PIV400, POV100, POV200, POV400, and A+SA60 groups respectively; colon with normal glands having normal mucosal and sub-mucosal layers (a), invasive adenocarcinoma (b), tubulovillous adenoma (c), villous adenoma (d), tubular adenoma (e), invasive carcinoma (f), villous adenoma with villous components (g), tubular adenoma (h), Tubular adenoma with increased number of glands (i).

Table 6 Effect of Vernonia Auriculifera on Serum Biochemical Parameters in Dimethylhydrazine-Induced Colorectal Cancer

Groups	Triglyceride (mg/dl)	Total Cholesterol (mg/dl)	Total Protein (mg/dl)
Normal control	59.82 ± 4.25	55.57 ± 1.24	6.54 ± 0.08
DMH20	89.25 ± 8.0^a**	71.43 ± 5.84^a*	5.60 ± 0.14^a*
ASA60	61.33 ± 5.05^b**	55.82 ± 0.84^b*	6.27 ± 0.22
Pre-initiation phase
PIV100	62.73 ± 1.62 ^b*	58.35 ± 1.27	5.75 ± 0.17
PIV200	63.20 ± 4.83 ^b*	59.95 ± 1.77	5.85 ± 0.14
PIV400	60.00 ± 2.68 ^b**	57.33 ± 4.07^b*	6.10 ± 0.16
Post-initiation phase
POV100	67.97 ± 2.82	63.52 ± 3.22	5.56 ± 0.22^a**
POV200	65.55 ± 6.36 ^b*	61.20 ± 2.05	5.63 ± 0.20^a*
POV400	63.77± 6.43 ^b*	58.72 ± 2.69	5.87 ±0.20

Notes: Data are expressed as mean ± standard error of the mean (SEM); n=6; Compared to normal control; ^bCompared to DMH20; ASA60, Aspirin 60 mg/kg; DMH20, dimethylhydrazine 20 mg/kg; PIV and POV; Pre-initiation and Post initiation V. auriculifera at 100, 200, and 400 mg/kg, respectively; *p<0.05; **p<0.01.