Investigation of in vivo potential of scorpion venom against skin tumorigenesis in mice via targeting markers associated with cancer development

Figures & data

Table 1 Effect of L. quinquestriatus crude venom extract on DMBA-initiated and croton oil-promoted mouse skin tumor incidence and tumor multiplicity

Groups	na	Number of tumor-bearing mice	Tumor incidence (%)	Tumor multiplicity
Group I	13	0	0	0
Group II	13	13	100	14
Group III	13	10	76.9	7.6
Group IV	13	12	92.3	8.4
Group V	13	11	84.6	6

Note:

a n indicates the number of mice in each group.

Abbreviation: DMBA, 7,12-dimethylbenz[a]anthracene.

Figure 1 Effect of Leiurus quinquestriatus venom extract on DMBA/croton oil-induced mouse skin tumorigenesis.

Notes: (A) Group I: only vehicle (0.2 mL acetone); (B) Group II: DMBA + croton oil; (C) Group III: DMBA + croton oil + L. quinquestriatus venom (17.5 μg per mouse); (D) Group IV: DMBA + croton oil + L. quinquestriatus venom (35 μg per mouse); and (E) Group V: DMBA + croton oil + L. quinquestriatus venom (52.5 μg per mouse).
Abbreviation: DMBA, 7,12-dimethylbenz[a]anthracene.

Figure 2 Effect of Leiurus quinquestriatus venom extract on histology of DMBA/croton oil-induced skin tumorigenesis.

Notes: Representative photomicrographs (magnification ×4, ×10, and ×20) depicting histological changes are shown. (A) Group I: only vehicle (0.2 mL acetone); (B) Group II: DMBA + croton oil; (C) Group III: DMBA + croton oil + L. quinquestriatus venom (17.5 μg per mouse); (D) Group IV: DMBA + croton oil + L. quinquestriatus venom (35 μg per mouse); and (E) Group V: DMBA + croton oil + L. quinquestriatus venom (52.5 μg per mouse). Vehicle-treated animals show normal histological pattern (A), DMBA + croton oil-treated animals show intense histological deformities (B), and DMBA + croton oil + L. quinquestriatus venom-treated animals show suppressed histological changes (C–E).
Abbreviation: DMBA, 7,12-dimethylbenz[a]anthracene.

Figure 3 Effect of Leiurus quinquestriatus venom extract on DMBA/croton oil-induced cutaneous proinflammatory cytokines.

Notes: (A) TNF-α; (B) IL-6; (C) IL-1β. Values are expressed as mean ± SEM (n=6). ***P<0.001 shows significant difference in DMBA + croton oil-treated Group II experimental animals compared with vehicle-treated Group I animals. ^#P<0.05, ^##P<0.01, and ^###P<0.001 show significant difference in the L. quinquestriatus venom-treated experimental animal groups (Groups III–V) compared with DMBA + croton oil-treated Group II animals. ns indicates nonsignificant reduction of TNF-α and IL-1β levels in the animals of experimental Group III compared to Group II animals.
Abbreviations: DMBA, 7,12-dimethylbenz[a]anthracene; IL, interleukin; SEM, standard error of the mean; TNF, tumor necrosis factor.

Figure 4 Effect of Leiurus quinquestriatus venom extract on cell proliferation marker Ki-67 in the chemically induced skin tumors.

Notes: Representative photomicrographs (magnification ×20; scale bar: 100 μm) of (A) Group I: only vehicle (0.2 mL acetone); (B) Group II: DMBA + croton oil; (C) Group III: DMBA + croton oil + L. quinquestriatus venom (17.5 μg per mouse); (D) Group IV: DMBA + croton oil + L. quinquestriatus venom (35 μg per mouse); and (E) Group V: DMBA + croton oil + L. quinquestriatus venom (52.5 μg per mouse). Group II animals showed more number and intense immunopositive staining of Ki-67 (arrows) compared with Group I animals. Groups containing L. quinquestriatus venom-treated animals exhibit reduced Ki-67 expression (arrows) compared to Group II animals.
Abbreviation: DMBA, 7,12-dimethylbenz[a]anthracene.

Figure 5 Effect of Leiurus quinquestriatus venom extract on NF-κB expression in chemically induced skin tumors.

Notes: Representative photomicrographs (magnification ×40; scale bar: 50 μm). (A) Group I: only vehicle (0.2 mL acetone); (B) Group II: DMBA + croton oil; (C) Group III: DMBA + croton oil + L. quinquestriatus venom (17.5 μg per mouse); (D) Group IV: DMBA + croton oil + L. quinquestriatus venom (35 μg per mouse); and (E) Group V: DMBA + croton oil + L. quinquestriatus venom (52.5 μg per mouse). Group II animals showed more immunopositive staining of NF-κB (arrows) compared with Group I animals. L. quinquestriatus venom-treated animals exhibit reduced NF-κB expression (arrows) compared to Group II animals.
Abbreviations: DMBA, 7,12-dimethylbenz[a]anthracene; NF-κB, nuclear factor kappa-B.

Figure 6 Effect of Leiurus quinquestriatus venom extract on COX-2 expression in chemically induced skin tumors.

Notes: Representative photomicrographs (magnification ×40; scale bar: 50 μm). (A) Group I: only vehicle (0.2 mL acetone); (B) Group II: DMBA + croton oil; (C) Group III: DMBA + croton oil + L. quinquestriatus venom (17.5 μg per mouse); (D) Group IV: DMBA + croton oil + L. quinquestriatus venom (35 μg per mouse); and (E) Group V: DMBA + croton oil + L. quinquestriatus venom (52.5 μg per mouse). Group II animals showed more immunopositive staining of COX-2 (arrows) compared with Group I animals. L. quinquestriatus venom-treated animals exhibit reduced COX-2 expression (arrows) compared to Group II animals.
Abbreviations: COX, cyclooxygenase; DMBA, 7,12-dimethylbenz[a]anthracene.

Figure 7 Effect of Leiurus quinquestriatus venom extract on Bcl2 expression in chemically induced skin tumors.

Notes: Representative photomicrographs (magnification ×40; scale bar: 50 μm). (A) Group I: only vehicle (0.2 mL acetone); (B) Group II: DMBA + croton oil; (C) Group III: DMBA + croton oil + L. quinquestriatus venom (17.5 μg per mouse); (D) Group IV: DMBA + croton oil + L. quinquestriatus venom (35 μg per mouse); and (E) Group V: DMBA + croton oil + L. quinquestriatus venom (52.5 μg per mouse). Group II animals showed more immunopositive staining of Bcl2 (arrows) compared with Group I animals. L. quinquestriatus venom-treated animal groups exhibit reduced Bcl2 expression (arrows) compared to Group II animals.
Abbreviations: Bcl2, B-cell lymphoma-2; DMBA, 7,12-dimethylbenz[a]anthracene.

Figure 8 Effect of Leiurus quinquestriatus venom extract on VEGF expression in chemically induced skin tumors.

Notes: Representative photomicrographs (magnification ×20; scale bar: 100 μm). (A) Group I: only vehicle (0.2 mL acetone); (B) Group II: DMBA + croton oil; (C) Group III: DMBA + croton oil + L. quinquestriatus venom (17.5 μg per mouse); (D) Group IV: DMBA + croton oil + L. quinquestriatus venom (35 μg per mouse); and (E) Group V: DMBA + croton oil + L. quinquestriatus venom (52.5 μg per mouse). Group II animals showed more immunopositive staining of VEGF (arrows) compared with Group I animals. L. quinquestriatus venom-treated animal groups exhibit reduced VEGF expression (arrows) compared to Group II animals.
Abbreviations: DMBA, 7,12-dimethylbenz[a]anthracene; VEGF, vascular endothelial growth factor.