AIM: To investigate the chemopreventive efficacy of the Indian medicinal plant Acanthus ilicifolius L Acanthaceae in a transplantable Ehrlich ascites carcinoma (EAC)- bearing murine model. METHODS: Male Swiss albino mice were divided into four groups: Group A was the untreated normal control; Group B was the EAC control mice group that received serial, intraperitoneal (ip) inoculations of rapidly proliferating 2 x 105 viable EAC cells in 0.2 mL of sterile phosphate buffered saline; Group C was the plant extract-treated group that received the aqueous leaf extract (ALE) of the plant at a dose of 2.5 mg/kg body weight by single ip injections, once daily for 10, 20 and 30 consecutive days following tumour inoculation (ALE control); and Group D was the EAC + ALE- treatment group. The chemopreventive potential of the ALE was evaluated in a murine model by studying various biological parameters and genotoxic markers, such as tumour cell count, mean survival of the animals, haematological indices, hepatocellular histology, immunohistochemical expression of liver metallothionein (MT) protein, sister-chromatid exchanges (SCEs), and DNA alterations.RESULTS: Treatment of the EAC-bearing mice with the ALE significantly (P < 0.001) reduced viable tumour cell count by 68.34% (228.7 x 106 ± 0.53) when compared to EAC control mice (72.4 x 106 ± 0.49), and restored body and organ weights almost to the normal values. ALE administration also increased (P < 0.001) mean survival of the hosts from 35 ± 3.46 d in EAC control mice to 83 ± 2.69 d in EAC + ALE-treated mice. Haematological indices also showed marked improvement with administration of ALE in EAC-bearing animals. There was a significant increase in RBC count (P < 0.001), hemoglobin percent (P < 0.001), and haematocrit value (P < 0.001) from 4.3 ± 0.12, 6.4 ± 0.93, and 17.63 ± 0.72 respectively in EAC control mice to 7.1 ± 0.13, 12.1 ± 0.77, and 30.23 ± 0.57 respectively in EAC + ALE-treated group, along with concurrent decrement (P < 0.001) in WBC count from 18.8 ± 0.54 in EAC control to 8.4 ± 0.71 in EAC + ALE. Furthermore, treatment with ALE substantially improved hepatocellular architecture and no noticeable neoplastic lesions or foci of cellular alteration were observed. Daily administration of the ALE was found to limit liver MT expression, an important marker of cell proliferation with concomitant reduction in MT immunoreactivity (62.25 ± 2.58 vs 86.24 ± 5.69, P < 0.01). ALE was also potentially effective in reducing (P < 0.001) the frequency of SCEs from 14.94 ± 2.14 in EAC control to 5.12 ± 1.16 in EAC + ALE-treated group. Finally, in comparison to the EAC control, ALE was able to suppress in vivo DNA damage by abating the generations of ‘tailed’ DNA by 53.59% (98.65 ± 2.31 vs 45.06 ± 1.14, P < 0.001), and DNA single-strand breaks (SSBs) by 38.53% (3.14 ± 0.31 vs 1.93 ± 0.23, P < 0.01) in EAC-bearing murine liver. CONCLUSION: Our data indicate that, ALE is beneficial in restoring haematological and hepatic histological profiles and in lengthening the survival of the animals against the proliferation of ascites tumour in vivo. Finally, the chemopreventive efficacy of the ALE is manifested in limiting MT expression and in preventing DNA alterations in murine liver. The promising results of this study suggest further investigation into the chemopreventive mechanisms of the medicinal plant A. ilicifolius in vivo and in vitro. AIM: To investigate the chemopreventive efficacy of the Indian medicinal plant Acanthus ilicifolius L Acanthaceae in a transplantable Ehrlich ascites carcinoma (EAC) - bearing murine model. METHODS: Male Swiss albino mice were divided into four groups: Group A was the untreated normal control; Group B was the EAC control mice group that received serial, intraperitoneal (ip) inoculations of rapidly proliferating 2 x 105 viable EAC cells in 0.2 mL of sterile phosphate buffered saline; Group C was the plant extract-treated group that received the aqueous leaf extract (ALE) of the plant at a dose of 2.5 mg / kg body weight by single ip injections, once daily for 10, 20 and 30 consecutive days following tumor ingestion (ALE control); and Group D was the EAC + ALE-treatment group The chemopreventive potential of the ALE was evaluated in a murine model by studying various biological parameters and genotoxic markers, such as tumor cell count, mean survival of the animals, haematological ind ices, hepatocellular histology, immunohistochemical expression of liver metallothionein (MT) protein, sister-chromatid exchanges (SCEs), and DNA alterations .RESULTS: Treatment of the EAC- bearing mice with the ALE significantly (P <0.001) reduced viable cell count by 68.34% (228.7 x 106 ± 0.53) when compared to EAC control mice (72.4 x 106 ± 0.49), and restored body and organ weights almost to the normal values. ALE administration also increased (P <0.001) mean survival of the hosts From 35 ± 3.46 d in EAC control mice to 83 ± 2.69 d in EAC + ALE-treated mice. Haematological indices also showed marked improvement with administration of ALE in EAC-bearing animals. There was a significant increase in RBC count (P <0.001 ), hemoglobin percent (P <0.001), and haematocrit value (P <0.001) from 4.3 ± 0.12, 6.4 ± 0.93, and 17.63 ± 0.72 respectively in EAC control mice to 7.1 ± 0.13, 12.1 ± 0.77, and 30.23 ± 0.57 in EAC + ALE-treated group, along with concurren t decremenFurther, treatment with ALE substantially improved hepatocellular architecture and no noticeable neoplastic lesions or foci of cellular alteration were observed. (d <0.001) in WBC count from 18.8 ± 0.54 in EAC control to 8.4 ± 0.71 in EAC + ALE. the ALE was found to limit liver MT expression, an important marker of cell proliferation with concomitant reduction in MT immunoreactivity (62.25 ± 2.58 vs 86.24 ± 5.69, P <0.01). ALE was also potentially effective in reducing (P <0.001) the frequency of SCEs from 14.94 ± 2.14 in EAC control to 5.12 ± 1.16 in EAC + ALE-treated group. Finally, in comparison to the EAC control, ALE was able to suppress in vivo DNA damage by abating the generations of ’tailed’ DNA by 53.59 % (98.65 ± 2.31 vs 45.06 ± 1.14, P <0.001), and DNA single-strand breaks (SSBs) by 38.53% (3.14 ± 0.31 vs 1.93 ± 0.23, P <0.01) in EAC-bearing murine liver. data indicates that, ALE is beneficial in restoring haemat ological and hepatic histological profiles and in lengthening the survival of the animals against the proliferation of ascites tumor in vivo. Finally, the chemopreventive efficacy of the ALE is manifested in limiting MT expression and in preventing DNA alterations in murine liver. The promising results of this study suggest further investigation into the chemopreventive mechanisms of the medicinal plant A. ilicifolius in vivo and in vitro.